JP5956183B2 - Exterior protection member for harness and manufacturing method thereof - Google Patents

Description

  The present invention relates to an exterior protection member for a harness composed of a synthetic resin bellows tube portion and a straight tube portion, such as a corrugated tube applied as an exterior member of an automobile wire harness, and a method for manufacturing the same.

  Conventionally, various harness exterior protection members such as a corrugated tube made of synthetic resin have been proposed in order to cover an electric wire arranged inside an automobile and protect it from interference with a vehicle body or the like.

  For example, Patent Literature 1 describes a harness exterior protection member (wire harness exterior protection material) composed of a bellows tube portion and a straight tube portion (straight tube portion). For example, straight tube portions are arranged in series between two bellows tube portions, one end side of one bellows tube portion, and the other end side of the other bellows tube portion. The bellows tube portion can be bent in a three-dimensional direction, and the straight tube portion has higher rigidity than the bellows tube portion and cannot be bent.

  The bellows tube portion is bent and wired according to the wiring harness wiring location of the vehicle, and the straight tube portion is wired straight. In the example of Patent Document 1, a harness exterior protection member is routed from a high-voltage battery behind a hybrid vehicle to a front inverter.

  Further, in Patent Document 1, as a method of manufacturing the harness exterior protection member, a fluid resin material is fed from an extruder through a die into a molding machine. The molding machine includes a bellows tube part molding die and a straight tube. Equipped with an upper mold mechanism and a lower mold mechanism in which the mold for partial molding is arranged in a loop so that it can be rotated continuously. And extruding.

JP 2009-143326 A (FIG. 1)

  However, in the conventional harness exterior protection member described above, when the straight pipe portion is rubbed by interference with the vehicle body or the like due to vibration during driving of the automobile, for example, the straight pipe portion is worn, There was a concern that the electric wire inserted into the exterior protection member may have an adverse effect.

  In addition, the straight tube portion has higher rigidity than the bellows tube portion and is difficult to bend, but since the material is a synthetic resin, the straight tube portion is not completely bent, and a further increase in rigidity of the straight tube portion has been expected.

  Also, for example, when wiring harnesses are routed, there is a concern that when the harness exterior protection member is bent strongly, it may be easily damaged from the boundary portion between the bellows tube portion and the straight tube portion. It was expected to increase the strength of the boundary with the part.

  In view of the above points, the present invention improves the wear resistance of the straight pipe portion in the harness exterior protection member including the bellows pipe portion and the straight pipe portion, and at least maintains the current rigidity of the straight pipe portion. The present invention provides a harness exterior protection member that can be improved and a method for producing the same, and a method for producing a harness exterior protection member that can increase the strength of the boundary portion between the bellows tube portion and the straight tube portion. Objective.

In order to achieve the above object, a harness exterior protective member according to claim 1 of the present invention is a synthetic resin harness composed of a bellows tube portion having alternating peaks and valleys and a straight tube portion. In the exterior protection member for an automobile, a plurality of annular grooves shallower than the depth of the trough are formed in parallel only at the outer periphery of the straight pipe at a pitch larger than the pitch of the trough, The width of the convex part between each groove part is defined to be larger than the width of the groove part and the peak part, and the inner peripheral surface of the bellows tube part is formed in irregularities corresponding to the peak part and the valley part, the inner peripheral surface of the straight tube portion is characterized by being substantially flat form to not flat without having annular groove.

  With the above configuration, the area of the outer periphery of the straight pipe portion increases and the straight pipe portion excluding the groove portion due to the annular shallow groove portion on the outer periphery of the straight pipe portion, that is, the groove portion having a smaller radial dimension than the plate thickness of the straight pipe portion. The wear resistance of the straight pipe part is enhanced by the convex part of the contact with the counterpart member such as the vehicle body or the floor with a small sliding resistance. Further, since the inner peripheral surface of the straight pipe portion is flat or substantially flat and the end face of the shallow groove portion on the outer periphery of the straight pipe portion is present, the bending rigidity of the straight portion is ensured.

  The harness exterior protection member according to claim 2 is the harness exterior protection member according to claim 1, wherein the inner peripheral surface of the bellows tube portion and the inner peripheral surface of the straight tube portion are continuously straight without any step. It is characterized by.

  With the above configuration, the electric wire is smoothly inserted into the inner space of the harness exterior protection member without being caught from the bellows tube portion or the straight tube portion.

  The harness exterior protection member according to claim 3 is the harness exterior protection member according to claim 1 or 2, wherein the depth of the groove is defined within a range of 5 to 20% of the plate thickness of the straight pipe portion. It is characterized by that.

  With the above configuration, the wear resistance of the straight pipe part with the groove part is improved experimentally compared with the straight pipe part without the groove part, and the bending rigidity of the straight pipe part with the groove part is compared with the straight pipe part without the groove part. It was improved to the same or better on a trial basis.

  The harness exterior protection member according to claim 4 is characterized in that, in the harness exterior protection member according to any one of claims 1 to 3, a convex portion of a latching clamp is latched in the groove portion. .

  With the above configuration, the locking clamp is mounted on the radially outer side of the groove portion of the straight pipe portion, the convex portion of the locking clamp is engaged with the groove portion, and the locking clamp is accurately positioned. Misalignment (unintentional movement) of the clamp in the longitudinal direction of the tube portion is prevented. The straight pipe portion is fixed to a counterpart member such as a vehicle body or a floor by a locking clamp.

  The harness exterior protection member according to claim 5 is the harness exterior protection member according to any one of claims 1 to 3, wherein a rib in the longitudinal direction of the tube portion is provided on an outer surface of the straight tube portion. Features.

  With the above configuration, the bending rigidity of the straight pipe portion is further increased by the axial ribs on the outer surface of the straight pipe portion. In addition, since the rib is in sliding contact with a mating member such as a vehicle body or a floor with low frictional resistance, wear on the outer surface of the straight pipe portion is prevented. It is preferable that a plurality of ribs are arranged symmetrically at two or four locations in the circumferential direction of the straight tube portion.

A method for manufacturing a harness exterior protection member according to claim 6 is a method for manufacturing a harness exterior protection member according to any one of claims 1 to 4, wherein the harness exterior protection member is formed by resin extrusion molding. The extrusion speed of the molten resin material from the nozzle of the machine is constant, the moving speed in the resin material extrusion direction of the mold for molding the bellows tube section is fast, and the resin material extrusion of the mold for molding the straight pipe section It is characterized in that the moving speed in the direction is specified to be slow.

  With the above configuration, the bellows tube portion is formed thin, and the straight tube portion is formed thick. The thickness of the bellows tube is thinner than that of the straight tube, which increases the flexibility of the bellows tube, and the thickness of the straight tube is thicker than that of the bellows tube. The bending rigidity of the part is increased.

The manufacturing method of the exterior protection member for harness according to claim 7 is the manufacturing method of the exterior protection member for harness according to claim 6 , wherein the boundary portion between the bellows tube portion and the straight tube portion is formed when the boundary portion is formed. It is characterized in that the moving speed of the mold is specified gradually slow or gradually.

  By the said structure, the thickness of the boundary part of a bellows pipe part and a straight pipe part is formed thickly, and the bending rigidity of a boundary part increases. “Slowly” is the speed when forming the straight tube portion next to the bellows tube portion, and “Slowly” is the speed when forming the bellows tube portion next to the straight tube portion. .

  According to the first aspect of the present invention, the shallow groove portion on the outer periphery of the straight tube portion can improve the wear resistance of the straight tube portion, and the rigidity of the straight tube portion is equivalent to that of the straight tube portion having no groove portion. It can be maintained or up. By increasing the wear resistance of the straight pipe part, wear of the straight pipe part is suppressed when the straight pipe part interferes with the mating member such as the vehicle body or floor due to vibration during vehicle travel, for example. The electric wire inserted inside the straight tube portion is safely protected. Also, by increasing the rigidity of the straight pipe part, for example, when wiring the harness exterior protection member to the mating member such as the vehicle body or floor, only the bellows pipe part is bent and the straight pipe part is routed. The positional accuracy can be improved.

  According to the invention of claim 2, the electric wire can be smoothly inserted into the inner space of the harness exterior protection member from the bellows tube portion or the straight tube portion without being caught, and the electric wire insertion workability is improved. Can do.

  According to the third aspect of the present invention, the wear resistance of the straight tube portion having the groove portion can be increased experimentally compared to the straight tube portion having no groove portion, and the bending rigidity of the straight tube portion having the groove portion can be increased. Compared to the straight pipe section with no, it was possible to improve it to the same level or more on a trial basis.

  According to the fourth aspect of the present invention, the convex portion of the locking clamp for fixing the straight pipe portion to the counterpart member such as the vehicle body or the floor is locked to the groove portion, so that the locking clamp is accurately While being able to position, the unexpected movement of the pipe part longitudinal direction of a clamp for latching can be prevented.

  According to the fifth aspect of the present invention, the wear resistance and bending rigidity of the straight pipe portion can be further increased by the ribs on the outer surface of the straight pipe portion.

According to the sixth aspect of the present invention, the thickness of the bellows tube portion is made thin, the thickness of the straight tube portion is made thick, the flexibility of the bellows tube portion is enhanced, and the bending rigidity of the straight tube portion is enhanced. be able to.

According to the seventh aspect of the present invention, the thickness of the boundary portion between the bellows tube portion and the straight tube portion is specified to be thick, and the bending rigidity of the boundary portion is increased, for example, the bellows tube of the harness exterior protection member When the portion is bent and routed to a counterpart member such as a vehicle body or a floor, breakage from the boundary portion can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a harness exterior protection member according to the present invention, (a) is a plan view in a straight free state, and (b) is a plan view in a bent state. It is a top view which similarly shows the similar form of the exterior protection member for harnesses. It is explanatory drawing which shows the abrasion-resistance test method of the exterior protection member for harnesses. The manufacturing method of the exterior protection member for harnesses is shown, (a) is an overall side view, (b) is a sectional view of the main part. It is a diagram explaining the principal part of the manufacturing method of the exterior protection member for harnesses. (A) (b) is a front view which shows each example of other embodiment of the exterior protection member for harnesses, respectively. (A) (b) is a side view perspective view which similarly shows the example from which other embodiments of the harness exterior protection member differ, respectively.

  1 (a) and 1 (b) show an embodiment of a harness exterior protective member according to the present invention. FIG. 1A shows a free state of the harness exterior protection member, and FIG. 1B shows a state where the bellows tube portion of the harness exterior protection member is bent.

  As shown in FIG. 1 (a), the harness exterior protection member 1 is composed of a synthetic resin bellows tube portion 2 and a straight tube portion 3, and the straight tube portion 3 is a shallow and narrow annular groove on the outer periphery. A plurality of (concave portions) 4 are provided in parallel, and the inner peripheral surface 5 of the straight pipe portion 3 is formed flat or substantially flat without having the groove portion 4 as in the outer periphery.

  The groove portions 4 are arranged at an equal pitch in the longitudinal direction of the straight tube portion 3. A wide convex portion 6 is formed between the groove portion 4 and the groove portion 4, and the width W1 of the groove portion 4 is defined to be approximately ½ or less of the width W2 of the convex portion 6. The width W1 of the groove part 4 is narrower than the width of the convex part 6. The depth H1 of the groove portion 4 is approximately 5 to 20% of the plate thickness T of the convex portion 6. The depth H1 of the groove portion 4 is formed to be extremely shallower than the depth H2 of the groove portion (recess or trough portion) 7 of the bellows tube portion 2. For example, the depth H1 is approximately half or less than the depth H2 of the groove portion 7 of the bellows tube portion 2. The depth is defined as follows (the depth H2 of the groove portion 7 of the bellows tube portion 2 can be arbitrarily set, so this value is only for reference).

  The groove portion 4 of the straight tube portion 3 is configured by being surrounded by a bottom surface 4a and front and rear end surfaces 4b in the longitudinal direction of the vertical tube portion having an extremely smaller dimension (depth) than the bottom surface 4a. The intersecting portion between the end surface 4b of the groove 4 and the outer peripheral surface 6a of the convex portion 6 may be continued by an arcuate surface 6b as shown in FIG. 1, or may intersect at a right angle.

  Although the groove part 4 is not formed in the inner peripheral surface 5 of the straight pipe part 3, in fact, the inner peripheral surface 5 of the straight pipe part 3 is said to be flat under the influence of the unevenness | corrugations 4 and 6 of the outer periphery at the time of resin molding mentioned later. In many cases, the shape becomes slightly wavy (substantially flat). Even in this case, there is no problem in actual use, and the wear resistance and rigidity of the straight portion 3 are not different from those of the flat inner peripheral surface 5. The kind of the synthetic resin material for forming the harness exterior protection member 1 can be appropriately set as necessary, either hard or soft.

The width W1 of the groove portion 4 of the straight tube portion 3 in this example is approximately the same as the width W3 of the groove portion 7 of the bellows tube portion 2. Further, the pitch P1 of the groove portion 4 of the straight tube portion 3 is approximately twice as large as the pitch P2 of the groove portion 7 of the bellows tube portion 2. These can be set as appropriate. While the inner peripheral surface 5 of the straight tube portion 3 is formed flat or substantially flat, the inner periphery of the bellows tube portion 2 is formed to be uneven, and the outer peripheral convex portion (mountain portion ) of the bellows tube portion 2 8. Constitutes a concave portion 9 opposite to the inner periphery of the bellows tube portion 2, and a concave portion 7 on the outer periphery of the bellows tube portion 2 constitutes a convex portion 10 opposite to the inner periphery of the bellows tube portion 2. The width W4 of the convex portion 8 on the outer periphery of the bellows tube portion 2 of this example and the width W3 of the concave portion 7 are defined to be substantially equal. The wall thickness T of the straight tube portion 3 is defined to be greater than the wall thickness of the bellows tube portion 2, and the bending rigidity of the straight tube portion 3 is enhanced.

  The inner peripheral surface 5 of the straight tube portion 3 continues straight without any step to the inner peripheral surface 10 of the bellows tube portion 2, that is, the peripheral surface of the convex portion 10 opposite to the inner periphery. That is, the inner diameter D1 of the straight tube portion 3 is set equal to the inner diameter D2 of the bellows tube portion 2. This is because when an electric wire (not shown) is inserted (penetrated) into the harness exterior protection member 1, the end opening 12 of the bellows tube portion 2 is inserted even if it is inserted from the end opening 11 of the straight tube portion 3. This is so that the electric wire can be smoothly inserted without being caught in any case.

  For example, as shown in a similar example in FIG. 2, when the straight tube portion 3 ′ is set to have a larger diameter than the example of FIG. 1A, the boundary portions 14 to 14 of the bellows tube portion 2 and the straight tube portion 3 ′. A step 15 is formed in the vicinity thereof, and since the outer diameter D3 of the straight tube portion 3 ′ is larger than the outer diameter D4 of the bellows tube portion 2 in the example of FIG. 2, the inner diameter D1 ′ of the straight tube portion 3 ′ is It becomes larger than the inner diameter D <b> 2 of the bellows tube portion 2, and the step 15 is easily generated. In this case, by inserting an unillustrated electric wire from the end opening 12 of the bellows tube portion 2, interference between the step 15 and the insertion tip of the electric wire can be prevented.

  In the example of FIG. 2, the width W <b> 1 ′ of the groove portion 4 ′ of the straight tube portion 3 ′ is defined to be slightly larger than the width W <b> 3 of the groove portion 7 of the bellows tube portion 2. In FIG. 2, the outer diameter D4 of the bellows tube portion 2 can be set to be the same as the outer diameter D3 of the straight tube portion 3 '. In that case, since the outer diameter (bottom diameter) D5 of the groove portion 7 on the outer periphery of the bellows tube portion 2 is also slightly increased, the step 15 between the straight tube portion 3 'and the bellows tube portion 2 is decreased. By defining the outer diameter of the straight tube portion 3 to be smaller than the outer diameter of the bellows tube portion 2 as in the example of FIG. 1, the straight tube portion 3 can be routed in a narrow space such as a vehicle.

  As shown in FIG. 1B, when the bending force F is applied to the harness exterior protection member 1, only the bellows tube portion 2 bends in the direction in which the bending force F is applied. For example, when the plate thickness T of the harness exterior protection member 1 is set to be thick (for example, about 2 mm), the bellows tube portion 2 is elastically restored when the bending force F of the bellows tube portion 2 is removed. Therefore (although the plate thickness T may be 2 mm or less, for example, about 1 mm), existing locking clamps (not shown) are attached to the straight tube portion 3 adjacent to the bellows tube portion 2 at two positions in the longitudinal direction of the bellows tube portion 2. It is preferable that the clamp for locking the straight tube portion 3 is locked and fixed to a counterpart member such as a vehicle body or a floor (not shown) in a form in which the bellows tube portion 2 is bent.

  In that case, the straight tube portion 3 similar to that on the right side is integrally disposed at the left end (position indicated by reference numeral 12) of the bellows tube portion 2 in FIG. 1, and the groove portions 4 of the front and rear straight tube portions 3 and 3 are provided. Utilizing, a band portion (convex portion) of a locking clamp (not shown) is wound around the groove portion 4 to be positioned and fixed, or a convex portion provided on the locking clamp is engaged (locked) with the groove portion 4. .

  The locking clamp is, for example, provided with a pillar standing at the base end of the band part and providing, for example, a pair of claw parts at the tip of the pillar, and provided with a hole part inserted through the band part from the tip of the band part, For example, a claw for locking, for example, a sawtooth projection on the back surface of the band portion is provided in the hole portion. When the width of the band part is wider than the width of the groove part 4, the rib-like convex part formed at the center in the longitudinal direction of the band part or the convex part provided at the base end part of the band part is engaged with the groove part 4. The band part can be positioned and the band part can be prevented from being moved in the longitudinal direction of the pipe part.

  In the example of FIG. 1, a longitudinal slit for wire insertion is not provided in the harness exterior protection member 1, but a longitudinal slit (not shown) for electrical wire insertion may be provided in the harness exterior protection member 1. Is possible. When there is a slit, it is not necessary to insert the electric wire from the end openings 11 and 12 of the harness exterior protective member 1, and the electric wire may be inserted into the slit in the radial direction by widening the slit.

  FIG. 3 shows a method of confirming the wear resistance of the straight pipe portion 3 of the harness exterior protection member 1 of FIG.

  In this test method, an aluminum pipe 16 made of a conductive metal is inserted through the straight pipe portion (sample) 3 of the harness exterior protective member 1 without any gap, and the lead wire 18 is connected to the electric wire 17 inserted and connected into the aluminum pipe 16. Connected to the continuity measuring device 19, a weight 20 is placed on the upper surface of the straight tube portion 3, and a belt-like wear is made via a conductive metal roller 21 that is rotatable on the lower surface of the straight tube portion 3 so as to face the weight 20. The tape 22 is brought into contact, the roller 21 is connected to the continuity measuring machine 19 by the electric wire 25, and the abrasion tape 22 is confirmed to have wear resistance with a configuration in which the conductive metal portions 22b are arranged at an equal pitch on the surface of the file-like portion 22a. This is performed using the testing machine 23. In FIG. 3, reference numeral 24 denotes a support for receiving the electric wire 17. The aluminum pipe 16 and the electric wire 17 may be a product that forms a wire harness. The wire harness includes, for example, a plurality of electric wires and a harness exterior protection member 1.

  Then, the roller 21 is disposed so as to face the groove portion 4 of FIG. 1 of the straight tube portion 3, the wear tape 22 is rotated in a loop shape by a drive unit (not shown), and straight at the file-like portion 22 a of the wear tape 22. When the outer peripheral surface of the tube portion 3 is rubbed and worn, and the straight tube portion 3 is worn and there is a hole, the conductive portion 22b of the wear tape 22 comes into contact with the aluminum pipe 16 inside the straight tube portion 3 to form aluminum. The pipe 16, the electric wire 17, the lead wire 18, the continuity measuring device 19, the roller 21, and the conductive portion 22 b of the wear tape 22 constitute a closed circuit, and the continuity measuring device 19 measures and displays the moving distance of the wear tape 22.

  As a result of performing this wear resistance confirmation test using a sample having a thickness T of 1 mm of the straight pipe portion 3, the wear resistance of the complete straight pipe portion in which the groove portion 4 is not provided in the straight pipe portion 3 (wear tape 22). 1) is 4050 mm, the wear resistance of the straight tube portion 3 having the groove portion 4 as shown in FIG. 1 is 4800 mm, and the straight tube portion 3 having the groove portion 4 is the groove portion 4. It has been found that the tube has superior wear resistance as compared with a straight pipe portion having no outer diameter (the outer diameter is the same).

  This is because the surface area of the straight tube portion 3 having the groove portion 4 is increased by the radial height H1 of the front and rear end surfaces 4b (FIG. 1) of the groove portion 4 as compared to the straight tube portion having no groove portion 4. (The surface area is a value obtained by adding the area of the front and back end surfaces 4b of the groove 4 and the area of the bottom surface 4a of the groove 4), and the moving distance of the wear tape 22 moving along the straight tube portion 3 having a large surface area is increased. The reason is that. Thus, it can be seen that the presence of the groove 4 sufficiently enhances the wear resistance when a relatively flexible portion of the counterpart member such as a vehicle body or a floor contacts the straight pipe portion 3. Further, even when a hard part of the counterpart member such as a vehicle body or a floor and the straight pipe portion 3 are in contact with each other, it is understood that the wear resistance is improved by scraping and wearing the front and rear end surfaces 4b of the groove portion 4. .

  Further, the presence of the groove 4 reduces the area of the outer peripheral surface 6a of the straight tube part 3 (the area of the outer peripheral surface 6a of the convex part 6 is smaller than that without the groove part 4), and the convex part 6 has a small area. By contacting the mating member such as the body and the floor, the sliding frictional resistance between the outer peripheral surface 6a of the convex portion 6 and the mating member such as the vehicle body and the floor is reduced, whereby the wear resistance of the straight pipe portion 3 is reduced. Can be said to improve. The depth of the groove portion of the straight pipe portion, which is a sample in the wear resistance test, is defined in the range of 5 to 20% of the plate thickness of the straight pipe portion.

  In addition to the above-described wear resistance test, a bending stress confirmation test of the straight pipe portion 3 is also performed. In a bending stress confirmation test (not shown), the straight pipe portion 3 is supported by two receiving tools (not shown) in the longitudinal direction, and the downward opening angle of 30 ° is intermediate between the two receiving tools. The maximum load generated when the straight pipe portion 3 is pressed downward and bent with a metal jig having the illustrated protrusion is measured.

The result of this bending stress confirmation test, the straight tube portion 3 having a groove 4, to exert the same or more bending load than the straight tube portion having no groove 4 was found. The reason for this is that straight pipes are formed by end faces 4b of the extremely shallow groove part 4 provided in the straight pipe part 3 before and after the pipe part longitudinal direction (the radial height H1 is extremely smaller than the plate thickness T of the straight pipe part 3). The rigidity of the bending direction of the part 3 is raised. For example, if there are irregularities 7 to 10 on the outer periphery and the inner periphery as in the bellows tube portion 2 (FIG. 1), the bending rigidity decreases due to the irregularities 7 to 10 on the inner periphery and the outer periphery. The groove portion 4 is extremely shallow, and the groove portion 4 is formed only on the outer periphery and is not formed on the inner peripheral surface 5, so the bending rigidity tends to increase (at least a straight pipe portion having no groove portion 4 The depth of the groove portion of the straight tube portion, which is a sample in the bending stress test, is defined in the range of 5 to 20% of the plate thickness of the straight tube portion.

  4 (a) and 4 (b) show an embodiment of a method for producing the harness exterior protection member 1 described above. There are two types of methods for manufacturing an exterior protective member for a harness, that is, air blow molding and vacuum molding. Both molding methods will be described using FIGS. 4A and 4B in common.

  The molding by the air blow method uses the resin extruder 31 and the blow molding machine 32 shown in FIG. 4A, and the extruder 31 pushes out the hopper 33 into which the resin material is introduced and the molten resin material at a constant speed. The blow molding machine 32 includes a plurality of molds 35 that rotate in the up and down directions of FIG. 4B, and each mold 35 is a mold 35a for molding a bellows tube portion. And a mold (not shown) for forming a straight pipe portion. The bellows tube molding die 35a has a deep groove 36 in parallel in the moving direction, and the straight tube mold has a shallow groove in parallel in the moving direction.

  Air is fed into the nozzle 34 and the harness exterior protection member 1 is resind along the inner peripheral surface of each die 35 (represented by reference numeral 36) in a state where the tip of the harness exterior protection member 1 is closed with a lid (not shown). Mold. In the molding machine 32, the upper and lower molds 35 are rotated to continuously extrude the harness exterior protection member 1, and the long harness exterior protection member 1 is wound around a drum (not shown). When a slit is made in the longitudinal direction of the harness exterior protection member 1, the slit is made by a take-up machine (not shown), and the harness exterior protection member 1 is wound around a bundler (not shown). The harness exterior protection member 1 is cut into a required length for use.

  Molding by vacuum is performed by vacuuming the inside of the mold 35 radially outward from a hole (not shown) provided in each mold 35 with the front end of the harness exterior protection member 1 opened (without using a lid). Then, the harness exterior protection member 1 is formed by bringing the molten resin material supplied from the nozzle 34 along the inner peripheral surface 36 of each mold 35. The harness exterior protection member 1 is continuously extruded by rotation of the upper and lower molds 35, and a slit is formed by a take-up machine (not shown), and the harness exterior protection member 1 is formed by a bundler. Wind up continuously. The shapes of the bellows tube portion molding die 35a and the straight tube portion molding die (not shown) are the same as in the blow molding machine.

  In each of the above molding methods, the supply speed of the molten resin material from the nozzle 34 of the resin extruder 31 is constant, and as shown in FIG. The thin bellows tube portion 2 is formed, and the feed rate of the mold for forming the straight tube portion is slowed to form the thick straight tube portion 3. In FIG. 5, the vertical axis indicates the feed rate of the die 35, and the horizontal axis indicates the longitudinal position of the harness exterior protection member 1, that is, the bellows tube portion 2 and the straight tube portion 3.

In order to increase the rigidity of the boundary portion 14 between the bellows tube portion 2 and the straight tube portion 3, the feed rate of the mold 35 is gradually increased in an inclined manner between the bellows tube portion 2 and the straight tube portion 3, or By gradually loosening, the thickness of the boundary portion 14 between the bellows tube portion 2 and the straight tube portion 3 is ensured to be thick. The mold feed rate is gradually increased from the front straight tube portion 3 to the bellows tube portion 2 (indicated by symbol A), and the mold feed speed is gradually decreased from the bellows tube portion 2 to the rear straight tube portion 3. (Denoted by symbol B).

  FIGS. 6-7 shows one Embodiment of the exterior protection member for harnesses which concerns on this invention. The configuration of the harness exterior protection members 41 and 41 ′ may be applied to the straight pipe portion 3 with the groove 4 of the harness exterior protection member 1 of FIG. 1 or the harness exterior protection member 1 of FIG. In addition to the straight pipe portion 3, the straight pipe portion having no groove portion may be applied.

  6 (a) and 6 (b) show examples in which ribs 44, 45, 44 and 46 in the longitudinal direction of the pipe portion are integrally formed at four locations in the circumferential direction of the straight pipe portions 43 and 43 'made of synthetic resin. It is. The ribs 43 to 46 protrude outward in the radial direction, and the outer surfaces 44a to 46a of the ribs 44 to 46 protrude outward in the radial direction from the outer peripheral surface 43a of the straight pipe portions 43 and 43 ′. Recessed groove-like inner surfaces 44b-46b of the ribs 44-46 protrude radially outward from the inner peripheral surface 43b of the portions 43, 43 ′.

  The ribs 44 and 45 in FIG. 6A are a pair of ribs 44 having a projecting cross section and ribs 45 having a substantially arcuate cross section arranged symmetrically in a 180 ° direction. The ribs 44 and 46 in FIG. 6B are formed by symmetrically arranging a pair of ribs 44 having a projecting cross section and a rib 46 having a rectangular or trapezoidal cross section in a 180 ° direction. The shape, combination, height, and plate thickness of the ribs 44 to 46 can be appropriately set according to the required characteristics of the straight pipe portions 43 and 43 '. If necessary, similar ribs can be formed on the bellows tube portions (not shown) of the harness exterior protection members 41 and 41 '.

  The ribs 44 to 46 extending in the longitudinal direction of the straight pipe portions 43 and 43 'increase the bending rigidity of the straight pipe portions 43 and 43'. Further, when the harness exterior protection members 41 and 41 'are routed to the mating member such as the vehicle body or the floor, the ribs 44 to 46 come into contact with the mating member, so that the straight pipe portions 43 and 43' The frictional resistance of the outer peripheral surface 43a is reduced, and the wear resistance of the harness exterior protection members 41 and 41 ′ is improved.

  7A and 7B, ribs 54 and 54 ′ having the same shape as the ribs 44 to 46 in FIG. 6 are appropriately selected and used in the longitudinal direction in the four circumferential directions of the straight pipe portions 53 and 53 ′. The form example extended continuously or discontinuously is shown. Each rib 54 in FIG. 7A is formed continuously in the longitudinal direction of the tube portion. The rib 54 ′ in FIG. 7B is intermittently formed in the longitudinal direction of the tube portion, like the groove portion 4 of the straight tube portion 3 in FIG. 1, and is used for locking to the groove-like portion 55 without the rib 54 ′. A locking clamp can be assembled by engaging a band part of a clamp (not shown) or a rib in the center in the width direction of the band part.

  The straight pipe portions 53 and 53 'have higher rigidity in the straight pipe portion 53 shown in FIG. 7A than in the straight pipe portion 53' shown in FIG. 7B. In the example of FIG. 7B, the rib 54 ′ is not completely cut out in the radial direction, but is cut out to the middle in the height direction of the rib 54 ′ to form a groove (55). It is also possible to ensure rigidity.

  In each of the embodiments shown in FIGS. 1, 6, and 7, the length, diameter, number, arrangement, and the like of the bellows tube portion 2 and the straight tube portions 3, 43, 53 of the harness exterior protection members 1, 41, 51 are as follows. It can be appropriately set as necessary. Further, in each of the embodiments described above, the harness exterior protection members 1, 41, 51 having a circular cross section are used. For example, for a harness having an oblong cross section (flat type) depending on the cross sectional shape of the electric wire inserted through the harness. It is also possible to use an exterior protection member (not shown).

  The harness exterior protection member and the manufacturing method thereof according to the present invention include a harness exterior protection member including a bellows tube portion and a straight tube portion. Can be used to maintain or improve at least the current state and to increase the strength of the boundary portion between the bellows tube portion and the straight tube portion.

DESCRIPTION OF SYMBOLS 1 Harness exterior protection member 2 Bellows pipe part 3 Straight pipe part 4 Groove part 5,10 Inner peripheral surface 14 Boundary part 31 Resin extruder 34 Nozzle 35 Mold 41, 41 ', 51, 51' Harness exterior protection member 44- 46, 54, 54 'rib H1 depth T thickness

Claims (7)

In the outer sheath protective member made of synthetic resin composed of a bellows tube portion having straight portions and valley portions alternately and a straight tube portion, only the outer periphery of the straight tube portion is shallower than the depth of the valley portion. A plurality of annular groove portions are formed in parallel at a pitch larger than the pitch of the valley portions, and the width of the convex portion between each groove portion of the straight tube portion is defined to be larger than the width of the groove portion and the peak portion. The inner peripheral surface of the bellows tube portion is formed to be uneven corresponding to the peak portion and the valley portion, and the inner peripheral surface of the straight tube portion is formed flat or substantially flat without having an annular groove portion. The exterior protection member for harnesses characterized by the above-mentioned.   The harness exterior protective member according to claim 1, wherein the inner peripheral surface of the bellows tube portion and the inner peripheral surface of the straight tube portion are continuously straight without any step.   The harness exterior protection member according to claim 1 or 2, wherein a depth of the groove is defined in a range of 5 to 20% of a plate thickness of the straight pipe portion.   The exterior protective member for a harness according to any one of claims 1 to 3, wherein a convex portion of the locking clamp is locked to the groove.   The exterior protection member for harnesses according to any one of claims 1 to 3, wherein a rib in the longitudinal direction of the pipe part is extended on an outer surface of the straight pipe part.   In the method for manufacturing a harness exterior protection member according to any one of claims 1 to 4, wherein the harness exterior protection member is formed by resin extrusion, the extrusion rate of the molten resin material from the nozzle of the resin extruder is constant. For a harness, characterized in that the speed of movement of the mold for molding the bellows tube portion in the resin material extrusion direction is defined fast, and the speed of movement of the mold for molding the straight tube section in the direction of resin material extrusion is defined slow. Manufacturing method of exterior protection member.   The harness exterior protection member according to claim 6, wherein when the boundary portion between the bellows tube portion and the straight tube portion is formed, the moving speed of the mold is specified to be gradually slow or gradually fast. Manufacturing method.

Images