Central joint part, wire harness, method for manufacturing central joint part

Abstract

To provide a concentrated joint part that can maintain water resistance of a conducting wire and can be manufactured at low cost at the same time.SOLUTION: A wire harness 1 has a concentrated joint part 3 formed by connecting an aggregate of a plurality of coated conducting wires 5. In the concentrated joint part 3, conducting wires 9 exposed from a coating part 7 are connected together. The conducting wires 9 exposed from the coating part 7 are all coated with a resin 11, including a conducting wire integration part 17. In the concentrated joint part 3, the resin 11 has a large-diameter part 13 in a top edge part of the conducting wire 9. The large-diameter part 13 is nearly hemispherical on the top end side. A small-diameter part 15 is formed closer to the coating part 7 side than the large-diameter part 13. The small-diameter part 15 has a smaller diameter than the large-diameter part 13 has.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a centralized joint portion of a large number of electric wires used in, for example, automobiles, a wire harness including the same, and a method for manufacturing the same.

Background Art

[0002] A wire harness used in an automobile or the like is used by joining a plurality of electric wires. As one method of connecting a plurality of electric wires, a method called a centralized joint is adopted. Since this centralized joint can easily join a plurality of electric wires, it is widely used in wire harnesses for automobiles and the like.

[0003] When electric wires are connected by this centralized joint, the conductor is exposed at the joint portion. Therefore, for insulation and protection, for example, a resin centralized joint cap (hereinafter sometimes simply referred to as a cap) is put on the joint portion. For example, a plurality of electric wires are inserted into the cap and fixed to the cap by a tape. In order to ensure the water stoppage property of the centralized joint portion where a plurality of electric wires are gathered in this way, a method has been proposed in which silicone rubber is filled in the cap with the tips of the plurality of electric wires inserted into the cap to form a water stoppage structure (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the method of Patent Document 1, the cap is formed of, for example, a hard resin in order to effectively protect the concentric joint portion from external impacts and the like. However, if the portion fixed to the electric wire with the tape is hard, the flexibility of the electric wire at that portion will decrease, which will cause a decrease in the degree of freedom of wiring the electric wire. In addition, in the conventional cap, it is necessary to prepare a large number of different types of caps according to the difference in the diameter of the electric wire bundle, and improvement has been demanded from the viewpoint of commonizing parts and reducing costs.

[0006] On the other hand, a method of ensuring water stoppage by covering the coating removal portion with a liquid ultraviolet curable resin and curing the resin in this state without using a cap can be considered. However, even if a part of the coating removal portion is integrated by welding or the like, if the tip of the electric wire is not integrally welded, there is a risk that the strands of the electric wire will become loose at the tip of the electric wire. Even if the ultraviolet curable resin is applied and cured in such a state, it is difficult to form a sufficient resin film thickness on the loose strands at the tip of the electric wire. For this reason, there has been a concern that an electrolytic solution such as salt water penetrates into the resin during vehicle mounting, leading to corrosion of the conductor portion.

[0007] The present invention has been made in view of such problems, and an object thereof is to provide a concentric joint portion or the like that can be manufactured at low cost while ensuring the waterproofness of the conducting wire.

Means for Solving the Problems

[0008] In order to achieve the above-described object, a first invention is a concentric joint portion in which a plurality of coated electric wires each including a conducting wire and a coating portion covering the conducting wire are joined, and at the tip portions of the plurality of coated electric wires, the coating portion is peeled off to expose the conducting wire, the respective conducting wires are joined to each other, and the conducting wire exposed from the coating portion is covered with resin, and the resin has, at the tip portion of the conducting wire, a large-diameter portion with a substantially hemispherical tip and a small-diameter portion formed on the coating portion side of the large-diameter portion and having a smaller diameter than the large-diameter portion. and the resin is a resin selected from at least one of an ultraviolet curable resin, a moisture curable resin, an anaerobic curable resin, and a thermosetting resin It is a concentric joint portion characterized by the above. A second invention is a concentrator joint portion in which a plurality of coated conductors each including a conductor and a coating portion covering the conductor are joined together. At the tip portions of the plurality of coated conductors, the coating portion is peeled off to expose the conductor, the conductors are joined together, and the conductors exposed from the coating portion are coated with a resin. The resin has, at the tip portion of the conductor, a large-diameter portion having a substantially hemispherical tip and a small-diameter portion formed on the coating portion side of the large-diameter portion and having a smaller diameter than the large-diameter portion, and the average thickness of the large-diameter portion is larger than the average thickness of the small-diameter portion. It is a concentrator joint portion characterized by this.

[0009] It is desirable that the average diameter of the large-diameter portion is 100 μm or more larger than the average diameter of the small-diameter portion.

[0010] It is desirable that the average thickness of the resin in the large-diameter portion is 200 μm or more.

[0011] It is desirable that the Shore D hardness of the resin after curing is 40 to 80.

[0012] It is desirable that the resin is a resin selected from at least one of silicone-based, acrylic-based, urethane-based, polyamide-based, epoxy-based, fluorine-based, polyvinyl butyral-based, phenol-based, polyimide-based, and acrylic rubber-based resins.

[0014] It is desirable that the conducting wire is selected from at least one of aluminum, aluminum alloy, copper, and copper alloy.

[0015] It is desirable that at least a part of the conducting wire is integrated by welding.

[0016] First 、2 According to the first invention, in the vicinity of the end of the concentrated joint portion, the resin covering the conducting wire is composed of a large-diameter portion with a substantially hemispherical tip and a small-diameter portion formed on the covering portion side of the large-diameter portion. Therefore, even when the conducting wire spreads at the tip, the conducting wire can be surely covered with the resin without using a cap.

[0017] Further, by making the average diameter of the large-diameter portion 100 μm or more larger than the average diameter of the small-diameter portion, the spread of the tip of the above-described conducting wire can be surely covered, and the excessive covering of the resin other than the tip portion can be reduced, thereby reducing the cost.

[0018] Moreover, if the average thickness of the resin in the large-diameter portion is 200 μm or more, the tip portion of the conducting wire can be surely protected.

[0019] In addition, if the Shore D hardness after curing of the resin is 40 to 80, since it is rubbery and soft, the concentrated joint portion can be effectively protected from external impacts and the like.

[0020] In addition, if the resin is a silicone-based, acrylic-based, urethane-based, polyamide-based, epoxy-based, fluorine-based, polyvinyl butyral-based, phenol-based, polyimide-based or acrylic rubber-based resin, the manufacturability is good and waterproofness can be ensured.

[0021] In addition, if the resin is an ultraviolet curable resin, moisture curable resin, anaerobic curable resin or thermosetting resin, the manufacturability is good.

[0022] Note that the conducting wire can be selected from aluminum, aluminum alloy, copper or copper alloy, and these may be mixed. Even in this case, since the tip of the conducting wire can be surely coated with resin, galvanic corrosion due to contact of different metals can be suppressed.

[0023] In addition, if at least a part of the conducting wires is integrated by welding, the conducting wires can be surely integrated. At this time, by integrating without using a ring or the like, it is possible to suppress the tip of the conducting wire from coming apart when inserting the conducting wire through the ring.

[0024] The 3 invention of claim is a wire harness characterized by comprising the concentrated joint portion according to the first invention.

[0025] The 3 invention according to claim can obtain a wire harness in which a large number of coated conducting wires are joined and the conducting wire portion is anticorrosive.

[0026] The 4The invention comprises a step of joining the conductors of a plurality of coated conductors each comprising a conductor and a coating portion covering the conductor, a step of immersing the conductors with their leading ends facing downward in resin, a step of holding the conductors in a pulled-up state for a predetermined time and allowing the resin to flow down, and a step of curing the resin in a state where the leading end of the resin covering the conductor at the leading end portion of the conductor becomes a large-diameter portion having a substantially hemispherical shape and a small-diameter portion having a diameter smaller than that of the large-diameter portion is formed on the coating portion side of the large-diameter portion. It is a method for manufacturing a concentrated joint portion characterized by comprising these steps.

[0027] While the conductor is in a pulled-up state, the diameter of the resin at the leading end portion of the conductor may be monitored, held until the large-diameter portion reaches a predetermined size, and the resin may be cured after the large-diameter portion reaches the predetermined size.

[0028] No. 4 According to the invention of No. , by providing a step of holding the conductor in a pulled-up state for a predetermined time and allowing the resin to flow down, a large-diameter portion having a substantially hemispherical leading end can be formed at the leading end portion of the conductor, and a small-diameter portion can be formed on the coating portion side of the large-diameter portion. In this state, by curing the resin, the conductor at the leading end portion can be reliably covered.

[0029] Also, while the conductor is in a pulled-up state, by monitoring the diameter of the resin at the leading end portion of the conductor and curing it in a state where a predetermined large-diameter portion is formed, the size of the resin leading end portion can be surely made constant.

Effect of the Invention

[0030] According to the present invention, it is possible to provide a concentrated joint portion or the like that can be manufactured at low cost while ensuring the waterproofness of the conductor.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0032] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the wire harness 1, and FIG. 2 is an enlarged view of the vicinity of the concentrated joint portion 3 of the wire harness 1. Note that FIG. 1 is a view showing the resin 11 in a perspective manner.

[0033] The coated wire 5 is composed of a conductor 9 and a coating portion 7 that coats the conductor 9. The conductor 9 is, for example, a stranded wire in which a plurality of strands are twisted together. The material of the conductor 9 is selected from at least one of, for example, aluminum, aluminum alloy, copper, or copper alloy. At the tip of each of the plurality of coated wires 5, the coating portion 7 having a predetermined length is peeled off to expose the conductor 9.

[0034] The wire harness 1 has a concentrated joint portion 3 where a plurality of coated wires 5 are gathered and joined. In the concentrated joint portion 3, the conductors 9 exposed from the coating portion 7 as described above are joined together. The joining of the conductors 9 may use, for example, a ring member or the like, but it is desirable to integrate at least a part of the conductors 9 by welding to form a conductor integrated portion 17. Note that the number and form of the coated wires 5 constituting the concentrated joint portion 3 are not limited to the illustrated example.

[0035] The conductor 9 exposed from the coating portion 7, including the conductor integrated portion 17, is entirely coated with the resin 11. That is, the entire conductor 9 is coated with the resin 11, and the conductor 9 is not exposed to the outside from the resin 11.

[0036] Next, the form of the resin 11 will be described in detail. As shown in FIG. 2, in the concentrated joint portion 3, a large-diameter portion 13 is formed at the tip of the conductive wire 9. The large-diameter portion 13 has at least a substantially hemispherical shape on the tip side. Note that the tip being substantially hemispherical means that the tip side is formed of a smooth curved surface and has no flat portion, and does not necessarily mean a constant radius of curvature or a form obtained by precisely bisecting a sphere. For example, it includes those having an overall substantially spherical shape and those having a shape flattened in the longitudinal direction or the width direction.

[0037] In the large-diameter portion 13, it is desirable that the average thickness of the resin 11 is 200 μm or more. Further, in the range of the large-diameter portion 13, it is desirable that the resin 11 covers the surface of the conductive wire 11 with a thickness of 200 μm or more at any position. In this case, also with respect to the maximum width (diameter) portion (B in the figure) of the conductive wire 9, the width (diameter) (A in the figure) of the resin 11 at this portion is at least 400 μm larger. Note that the maximum width (diameter) portion of the conductive wire 9 is the portion where the width (diameter) is the largest on the tip side of the conductive wire integrated portion 17. For example, if there is dispersion in the conductive wire 9, it is the tip of the conductive wire 9.

[0038] Also, a small-diameter portion 15 is formed on the covering portion 7 side of the large-diameter portion 13. The small-diameter portion 15 is a portion having a smaller diameter than the large-diameter portion 13. It is desirable that the average diameter of the large-diameter portion 13 is 100 μm or more larger than the average diameter of the small-diameter portion 15.

[0039] Note that the boundary between the large-diameter portion 13 and the small-diameter portion 15 is not necessarily clear. For example, a portion having a larger diameter of the resin 11 than the overall outer diameter of the covering portion 7 (for example, the diameter immediately above the resin at a portion where the resin 11 is not attached, D in the figure) is defined as the large-diameter portion 13. That is, when the conductive wire portion is made straight, in a side view, a portion on the tip side of the conductive wire 9 (that is, excluding the covering portion 7 side) where all the extension lines of the outer peripheral portion of the covering portion 7 are included is defined as the large-diameter portion 13. Also, the small-diameter portion 15 is between the large-diameter portion 13 and the covering portion 7, and for example, a portion where a part of the extension line of the outer peripheral portion of the covering portion 7 passes outside the resin 11.

[0040] The average diameter of the large-diameter portion 13 and the average diameter of the small-diameter portion 15 are measured as follows. In a side view of the wire harness 1 seen from an arbitrary circumferential direction, the diameter of the largest-diameter portion (A in the figure) in the large-diameter portion 13 and the diameter of the central portion in the longitudinal direction of the conductor 9 exposed from the covering portion 7 (the diameter of the small-diameter portion 15) are measured. Each diameter can be measured by using a shape measurement function such as a digital microscope for the concentrated joint portion 3 after curing the resin 11, or can be measured with calipers. Also, regarding the thickness of the resin 11, the maximum width (diameter) portion of the conductor 9 and the diameter of the conductor 9 at the portion where the diameter of the small-diameter portion 15 is measured are measured respectively, and the film thickness of the resin 11 at each portion can be obtained from the difference from each of the diameters measured above. However, the above is limited to the case where the resin 11 is mainly an ultraviolet-curable resin and is light-transmittable, and the conductor 9 is visible through the resin 11 with a microscope or the like. For example, in resins such as moisture-curing resins, anaerobic-curing resins, or thermosetting resins alone that do not necessarily need to transmit ultraviolet rays, they may be colored. In such a case, it may be difficult to calculate the film thickness of the resin 11 using the above microscope. In such a case, the diameter of the conductor 9 is measured in advance with a microscope or calipers before applying the resin, and the film thickness can be obtained from the difference from the same measured value after applying the resin. By measuring and averaging the diameters of the large-diameter portion 13 and the small-diameter portion 15 and the film thickness of the resin 11 at each portion from an arbitrary 5 directions in the circumferential direction by the above method, the average diameter of the large-diameter portion 13, the average diameter of the small-diameter portion 15, and the average film thickness of the resin 11 at each portion can be measured.

[0041] Next, a method for manufacturing the concentrated joint portion 3 (wire harness 1) will be described. First, as described above, the covering portions 7 with a predetermined length at the tips of the plurality of covered conductors 5 are each peeled off to expose the internal conductors 9. Next, the exposed conductors 9 of the plurality of covered conductors 5 are joined together. The joining may be, for example, arc welding, laser welding, ultrasonic joining, etc., or may use crimping or other caulking members.

[0042] Next, as shown in Fig. 3(a), the integrated coated conductor 5 is immersed in the uncured resin 11 with the tip side of the conductor 9 facing downward. As the resin 11, for example, at least one resin selected from silicone-based, acrylic-based, urethane-based, polyamide-based, epoxy-based, fluorine-based, polyvinyl butyral-based, phenol-based, polyimide-based, and acrylic rubber-based resins can be used.

[0043] Next, as shown in Fig. 3(b), the conductor 9 is completely pulled out of the resin 11 from the tank in which the resin 11 is stored (arrow E in the figure). Then, with the tip of the conductor 9 facing downward, it is held for a predetermined time to allow the resin 11 to flow down. During the holding process, the coated conductor 5 may be moved from above the tank to the next process.

[0044] Fig. 4 is a conceptual diagram showing the flow-down state of the resin 11 when held in the state of being pulled out from the resin 11. Immediately after the conductor 9 is pulled out (Fig. 4(a)), the resin 11 adheres to substantially the entire conductor 9 (and a part of the coating portion 7, the same applies hereinafter). If held as it is, the resin 11 flows downward due to gravity, and the resin 11 accumulates on the tip side of the conductor 9 (Fig. 4(b)). At this time, droplets of the resin 11 gradually become substantially spherical at the tip portion of the conductor 9. That is, a large-diameter portion is formed.

[0045] Furthermore, if held as it is, the resin 11 further flows down to the tip portion of the conductor 9, and the shape of the resin 11 at the tip portion of the conductor 9 becomes larger (Fig. 4(c)). When the resin 11 at the tip portion of the conductor 9 reaches a certain size, the resin 11 drips downward (Fig. 4(d)). In this state, the amount of the resin 11 at the tip portion of the conductor 9 suddenly decreases, and the size also becomes smaller. If the resin 11 adheres sufficiently, the form may further change from Fig. 4(b) to Fig. 4(c) thereafter.

[0046] Thus, the form of the resin 11 changes according to the holding time. Therefore, at the tip of the conductive wire 9, the tip of the resin 11 before curing that coats the conductive wire 9 becomes the shape of a large-diameter portion 13 with a substantially hemispherical shape, and it is held until the coated portion side of the large-diameter portion 13 becomes the shape of a small-diameter portion 15, and by curing the resin 11 in that state, the large-diameter portion 13 and the small-diameter portion 15 can be formed.

[0047] Note that the holding time may be determined in advance according to the type of the resin 11 or the like, but as shown in FIG. 3(b), for example, the form of the resin 11 may be monitored by an imaging device 19 such as a CCD camera. In this case, it may be held until the large-diameter portion 13 reaches a predetermined size, and the curing of the resin 11 may be started after the large-diameter portion 13 reaches the predetermined size. Note that instead of the imaging device 19, the size of the resin 11 may be monitored by a laser sensor or the like. Also, as described above, the monitoring may be performed after moving to the curing process instead of on the tank.

[0048] Here, it is desirable that the resin 11 is a resin selected from at least one of an ultraviolet-curable resin, a moisture-curable resin, an anaerobic-curable resin, and a thermosetting resin. For example, when the resin 11 is an ultraviolet-curable resin, after finishing the above-described holding process, the resin 11 can be cured by immediately irradiating the resin 11 with ultraviolet rays. At this time, for example, ultraviolet rays may be irradiated from below the conductive wire 9.

[0049] Also, a combined type resin of an ultraviolet-curable resin and a moisture-curable resin or an anaerobic-curable resin, or a thermosetting resin may be used. To form a large-diameter portion 13 having a hemispherical curved surface on the tip surface, which has a larger diameter than the coating portion 7, for example, at the tip of the conductive wire 9, an ultraviolet-curable resin capable of being rapidly cured at a predetermined timing is suitable. On the other hand, it is difficult for ultraviolet rays from the outside to reach the resin 11 that has penetrated between the strands. Therefore, it is preferable that the inside is cured by a moisture-curable resin, an anaerobic-curable resin, or a thermosetting resin.

[0050] When using an ultraviolet curable resin, it is preferable to use an ultraviolet curable acrylic resin. Specific examples of the ultraviolet curable acrylic resin include acrylate resins, methacrylate resins, urethane acrylate resins, urethane methacrylate resins, epoxy acrylate resins, epoxy methacrylate resins, polyester acrylate resins, polyester methacrylate resins, and the like. Further, it is preferable that the ultraviolet curable resin contains a photoinitiator that activates and initiates the curing of the resin when irradiated with ultraviolet light. When using a moisture curable resin, in addition to cyanoacrylate resins and silicone resins, silicone acrylate resins are preferable when using both ultraviolet curing and moisture curing in combination. Anaerobic curable resins are blocked from air (oxygen), and a radical chain reaction occurs by contact with an active material such as metal, and curing proceeds even at room temperature. The main component is an acrylic resin, which is composed of a reaction initiator that starts the reaction in the presence of metal, etc. Examples of the main component include acrylate resins, methacrylate resins, urethane acrylate resins, urethane methacrylate resins, epoxy acrylate resins, epoxy methacrylate resins, polyester acrylate resins, polyester methacrylate resins, and the like. Anaerobic adhesives are most suitable for bonding metals, but can also be used for some inert materials such as plastics when an activator is added as an activator. When using a thermosetting resin, phenolic resins, epoxy resins, melamine resins, urea resins (urea resins), unsaturated polyester resins, alkyd resins, polyurethane resins, polyimides, diallyl phthalate resins, silicone resins, etc. can be used. Further, as the thermosetting resin, a room temperature curable resin can also be used. In addition, the above adhesives may be used alone or in combination of two or more.

[0051] Here, in order to surely form the large-diameter portion 13, it is desirable that the viscosity of the resin 11 before curing is 200 mPa·s to 5000 mPa·s. If the viscosity is less than 200 mPa·s, the droplets will fall in a short time, and it will be difficult to form a hemispherical shape with a large diameter of a predetermined size. On the other hand, if the viscosity exceeds 5000 mPa·s, the resin will not sag to the tip by its own weight, and a large amount of adhered resin layer will be formed not only at the tip of the wire bonding portion but also at portions other than the tip, resulting in a need for more resin than necessary, which is uneconomical.

[0052] In addition, after the lifting, the holding time until the shape of the large-diameter portion is formed is, for example, about 10 seconds, and more preferably, it is 20 seconds to 90 seconds. If it exceeds 90 seconds, it will take too much time in the coating and curing process, resulting in poor production efficiency. If it is less than 10 seconds, it will be difficult to form a sphere of sufficient size at the tip. The holding time is appropriately set according to the size and shape of the wire bonding portion and the viscosity of the resin.

[0053] Further, as the resin 11 in the present invention, it is desirable that the Shore D hardness after curing is 40 to 80. Compared with the case of covering the concentrated joint portion 3 with a hard resin as in the prior art, by making the resin 11 after curing rubbery and soft, the flexibility of the wire at that portion will not be reduced. Therefore, the degree of freedom in routing the wire harness 1 will not be reduced. In addition, since the resin 11 is rubbery and soft, it can withstand external impacts. If the Shore D hardness of the resin 11 is less than 40, the strength of the resin 11 will be small, and there is a concern that the resin 11 will crack when an external force is applied. If the Shore D hardness of the resin 11 exceeds 80, it will become hard, resulting in a decrease in flexibility and a loss of the degree of freedom in routing the wire harness.

[0054] As described above, according to the present embodiment, by forming a large-diameter portion 13 of a predetermined size at the tip of the conductive wire, even if there is some variation at the tip of the conductive wire 9, the conductive wire 9 can be surely coated with the resin 11. At this time, the outer periphery may be further coated with a conventionally used cap, but the cap is not necessarily required. Further, since portions other than the tip portion of the conductive wire 9 are coated with the small-diameter portion 15, the amount of resin 11 used can be reduced.

[0055] Further, if the resin 11 is an ultraviolet-curable resin, the resin 11 can be cured immediately at the timing of curing. At this time, by combining a moisture-curable resin, an anaerobic-curable resin, or a thermosetting resin, the resin 11 can be surely cured even inside the conductive wire.

[0056] Also, by integrating the conductive wires 9 by welding, it is not necessary to use a conventionally used ring member or the like. Therefore, when the conductive wire 9 is inserted into the ring member, it is possible to suppress the tip of the conductive wire 9 from being scattered.

[0057] Further, since the Shore D hardness of the resin 11 after curing is within a predetermined range, the degree of freedom of routing of the wire harness is not reduced due to appropriate flexibility, and the strength of the resin 11 can be ensured.

[0058] As described above, a wire harness with excellent waterproof performance can be obtained.

Example

[0059] Next, a plurality of concentrated joint portions were prototyped and tested for each sample, and the results will be described below.

[0060] Two aluminum-coated conductors (0.75 sq) and two copper-coated conductors (0.75 sq) were prepared. The coating parts at both ends were peeled off to expose the conductors and the conductors were integrated. The outer diameter of the collective part in the coating part was 3.3 mm. In that state, resin was applied by the method shown in Figure 3 and cured in a desired form. The form of the resin was changed by changing the viscosity and holding time of the resin. Each condition is shown in Table 1 and Table 2.

[0061]

Table 1

[0062]

Table 2

[0063] For No.1 to No.3 and No.8, acrylate resin (UV curable type) (product name: 3094, manufactured by Three Bond Co., Ltd.) was used as the resin. For No.4, acrylate resin (UV curable type) (product name: 3013M, manufactured by Three Bond Co., Ltd.) was used as the resin. For No.5, acrylate resin (UV curable type) (product name: 3094B, manufactured by Three Bond Co., Ltd.) was used as the resin. For No.6, silicone acrylate resin (UV + moisture curable type) (product name: 3056F, manufactured by Three Bond Co., Ltd.) was used as the resin. For No.7, acrylate resin (UV + anaerobic curable type) (product name: 3062K, manufactured by Three Bond Co., Ltd.) was used as the resin. For No.9, acrylate resin (UV curable type) (product name: 3052, manufactured by Three Bond Co., Ltd.) was used.

[0064] No. 10 used a one - component epoxy resin (thermosetting type) (product name: EP106NL, manufactured by Cemedine Co., Ltd.), No. 11 used a two - component curing epoxy resin (room temperature (heat) curing type) (product name: EP007, manufactured by Cemedine Co., Ltd.), No. 12 used a one - component addition type silicone resin (thermosetting type) (product name: TSE3281 - G, manufactured by Momentive), No. 13 used a two - component curing silicone resin (thermosetting type) (product name: TSE3380, manufactured by Momentive), and No. 14 used an acrylate resin (UV + heat curing type) (product name: 3042, manufactured by Three Bond).

[0065] Also, as the heat curing conditions after coating, for No. 1 - 9, a UV - LED (365 nm) was used, with an illuminance of 100 mW / cm 2 and an irradiation time of 30 sec (integrated light quantity 3,000 mJ / cm 2 ) for UV curing. Also, for No. 6 and 7, after UV curing, they were left at room temperature for 1 week for moisture or anaerobic curing. For No. 10, it was 120 °C × 1 h, for No. 11, it could be either 80 °C × 1 h or left at room temperature of 23 °C for 7 days, or a combination of heat curing and room temperature curing could be used. For example, it could be cured at 80 °C × 30 min and then at room temperature of 23 °C for 3.5 days. For No. 12, it was 150 °C × 1 h, and for No. 13, it was 150 °C × 0.5 h. The UV curing conditions for No. 14 were using a UV - LED (365 nm), with an illuminance of 100 mW / cm 2 and an irradiation time of 30 sec (integrated light quantity 3,000 mJ / cm 2 ) for UV curing, and then further heat cured at 60 °C × 1 h.

[0066] Also, in the table, the "major - diameter part diameter" is the average diameter when viewed from 5 directions in the major - diameter part, and the "minor - diameter part diameter" is the average diameter when viewed from 5 directions at approximately the center of the minor - diameter part (approximately the center of the wire exposed part). The "minor - diameter part resin film thickness" and "major - diameter part resin film thickness" in the table are the average thicknesses of the resin at the respective outer - diameter measurement parts.

[0067] In the table, the "Shore D hardness" was measured according to the method of JIS K7215. A 1-mm-thick sheet was made, and two sheets were stacked and measured with Shore D. For flexible resins, the Shore A hardness was measured according to the method of JIS K7215, and then a numerical conversion to Shore D hardness was performed. Shore A and Shore D can be converted from a hardness comparison table. For example, a comparison table of measurement values by a durometer described in the durometer / IRHD hardness meter catalog of Teclock Corporation can be referred to.

[0068] In the table, for "coating of electric wire", those with the wire completely coated were marked as "○". Also, in the table, "flexibility" was judged by the resistance when the concentrated joint part was fixed with a vice and the resin-coated part was bent. At this time, those that were easy to bend were marked as "〇", those that were slightly difficult to bend were marked as "△", and those that did not bend were marked as "×".

[0069] Also, for "resistance value variation" in the table, out of 5 coated conductors, any 2 were selected, and the initial resistance values between the 2 conductors of all combinations were measured. Next, the resistance values between the respective conductors after the durability test (after immersion in 3% salt water for 48 hours and then in damp heat at 60°C - 95% for 48 hours) were measured. The initial resistance value and the resistance value after the durability test were compared, and those with the difference being 0.5 mΩ or less were marked as "〇", those with a difference exceeding 0.5 mΩ and being 1.0 mΩ or less were marked as "△", and those with a difference exceeding 1 mΩ were marked as "×".

[0070] Also, for "water stoppage between wires" in the table, as shown in Fig. 5, out of 5 coated conductors 5, 1 was selected, and air was sent in at a pressure of 30 kPa by a regulator 23 (F in the figure), and it was evaluated whether there was any air leakage (G in the figure) from the other 4 coated conductors 5 immersed in the water in the water tank 21. This evaluation was carried out by sending pressurized air from each coated conductor 5, and those with no leakage due to pressurization from all coated conductors 5 were marked as "〇", those with slight leakage in any of the coated conductors 5 were marked as "△", and those with a large leakage amount in any of the coated conductors 5 were marked as "×".

[0071] From Table 1, for all of No.1 to No.14, it was possible to completely cover the electric wire with resin without any part of the electric wire being exposed from the resin. In particular, for No.1 to No.7 and No.10 to No.14, large-diameter portions of sufficient size were formed and the film thickness was also sufficient, so they were all Δ or above in all evaluations. Furthermore, for those in which moisture curing and anaerobic curing were used in combination in addition to ultraviolet curing, the water stoppage between wires became ○.

[0072] On the other hand, for No.8, since a large-diameter portion of sufficient size was not formed, the resistance value fluctuation became ×. Also, for No.9, although the resistance value fluctuation was ○, the Shore D hardness was too large, so the flexibility became ×.

[0073] As described above, the embodiments of the present invention have been described with reference to the attached drawings. However, the technical scope of the present invention is not limited by the above-described embodiments. It is obvious that those skilled in the art can conceive various modification examples or correction examples within the scope of the technical idea described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention.

Explanation of Signs

[0074] 1………Wire harness 3………Concentrated joint part 5………Coated conductor 7………Coated part 9………Conductor 11………Resin 13………Large-diameter part 15………Small-diameter part 17………Conductor integrated part 19………Imaging device 21………Water tank 23………Regulator

Claims

1. A concentric joint part in which a plurality of coated conductors each composed of a conductor and a coating part covering the conductor are joined together, at the tip portions of the plurality of coated conductors, the coating parts are peeled off to expose the conductors, the respective conductors are joined together, and the conductors exposed from the coating parts are coated with resin, the resin has, at the tip portion of the conductor, a large-diameter portion with a substantially hemispherical tip and a small-diameter portion formed on the coating part side of the large-diameter portion and having a smaller diameter than the large-diameter portion, the concentric joint part is characterized in that the resin is a resin selected from at least one of an ultraviolet curable resin, a moisture curable resin, an anaerobic curable resin, and a thermosetting resin.

2. A concentric joint part in which a plurality of coated conductors each composed of a conductor and a coating part covering the conductor are joined together, at the tip portions of the plurality of coated conductors, the coating parts are peeled off to expose the conductors, the respective conductors are joined together, and the conductors exposed from the coating parts are coated with resin, the resin has, at the tip portion of the conductor, a large-diameter portion with a substantially hemispherical tip and a small-diameter portion formed on the coating part side of the large-diameter portion and having a smaller diameter than the large-diameter portion, the concentric joint part is characterized in that the average thickness of the large-diameter portion is larger than the average thickness of the small-diameter portion.

3. The concentric joint part according to claim 1 or claim 2, wherein the average diameter of the large-diameter portion is 100 μm or more larger than the average diameter of the small-diameter portion.

4. The concentric joint part according to any one of claims 1 to 3, wherein the average thickness of the resin in the large-diameter portion is 200 μm or more.

5. The concentric joint part according to any one of claims 1 to 4, wherein the Shore D hardness of the resin after curing is 40 to 80.

6. The concentric joint part according to any one of claims 1 to 5, wherein the resin is a resin selected from at least one of a silicone-based, acrylic-based, urethane-based, polyamide-based, epoxy-based, fluorine-based, polyvinyl butyral-based, phenol-based, polyimide-based, and acrylic rubber-based resins.

7. The concentric joint part according to any one of claims 1 to 6, wherein the conductor is selected from at least one of aluminum, an aluminum alloy, copper, and a copper alloy.

8. The concentrated joint part according to any one of claims 1 to 7, characterized in that at least a part of the wire is integrated by welding.

9. A wire harness, comprising the concentrated joint part according to any one of claims 1 to 8.

10. A step of joining the wires of a plurality of coated wires composed of a wire and a coating part covering the wire; A step of dipping the tip side of the wire downward into the resin; A step of holding the wire in a pulled-up state for a predetermined time and allowing the resin to flow down; A step of curing the resin in a state where the tip of the resin covering the wire becomes a large-diameter part having a substantially hemispherical shape at the tip of the wire, and a small-diameter part having a diameter smaller than that of the large-diameter part on the coating part side of the large-diameter part; A method for manufacturing a concentrated joint part, characterized by comprising the above steps.

11. While the wire is in a pulled-up state, monitoring the diameter of the resin at the tip of the wire and holding until the large-diameter part reaches a predetermined size; The method for manufacturing a concentrated joint part according to claim 10, characterized in that the resin is cured after the large-diameter part reaches a predetermined size.

Images