Wire harness and lighting device

Abstract

The invention provides a wire harness and a lighting device using the wire harness, wherein the arrangement freedom degree of a connection object is improved. A wire harness (1) is provided with a trunk cable (2) extending from an upstream side (A) to a downstream side (B), a plurality of branch sections (3) provided at each of a plurality of branch locations on the trunk cable (2), and a plurality of branch cables (4) branching from the plurality of branch sections (3), the trunk cable (2) having a trunk conductor (21), the branch cables (4) having branch conductors (41), and the branch conductors (41) being arranged in the trunk cable (2). The branching section (3) is provided with: a sleeve (30) for linear docking, which electrically connects the trunk line conductor (21) on the upstream side (A) to the trunk line conductor (21) and the branch line conductor (41) on the downstream side (B); and a heat-shrinkable tube (31), an inner molded body (32), and an outer molded body (33), which cover the sleeve (30) for linear docking and the periphery thereof with an insulating material.

Description

Technical Field

[0001] This invention relates to wire harnesses and lighting devices. Background Technology

[0002] In recent years, in order to reduce the number of components and reduce costs, a waterproof socket that can directly connect to a straight tube LED light and a lighting device using the waterproof socket have been proposed (see, for example, Patent Document 1).

[0003] The waterproof socket described in Patent Document 1 is a socket that houses the lamp head of a single-sided powered straight tube LED lamp at one end and supplies power to the straight tube LED lamp via socket terminals. The socket terminals have a structure for connecting one connecting wire to other connecting wires. Therefore, power can be supplied to multiple straight tube LED lamps from an external power source via connecting wires, and the straight tube LED lamps can be used in lighting devices, such as those for artificial vegetable cultivation.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-107741

[0005] According to existing lighting fixtures, the straight tube LED light of the connected object is directly connected to the waterproof socket set on the connecting line. Therefore, there is a problem that the configuration of the straight tube LED light is restricted by the waterproof socket (for example, the straight tube LED light cannot be configured away from the connecting line). Summary of the Invention

[0006] The objective of this invention is to provide a wire harness that enables greater freedom in the configuration of connected objects, and a lighting device using the wire harness.

[0007] [1] A wire harness comprising: a trunk line extending from an upstream side to a downstream side; a plurality of branches, each branching off from the trunk line; and a plurality of branch lines branching off from the plurality of branch lines.

[0008] in,

[0009] The aforementioned trunk line has a trunk conductor.

[0010] The aforementioned branch line has a branch conductor.

[0011] The aforementioned branch includes: a conductor connection portion that electrically connects the upstream main conductor to the downstream main conductor and the branch conductor; and a covering portion that covers the conductor connection portion and its surrounding area with an insulating material.

[0012] [2] According to the wire harness described in [1] above, wherein,

[0013] The aforementioned covering part has:

[0014] A tubular body that covers the aforementioned conductor connection portion and its surrounding area;

[0015] The inner molded body, with resin molded on the outer side of the aforementioned tubular body; and

[0016] The outer molded body is formed on the outside of the aforementioned inner molded body.

[0017] [3] According to the wire harness described in [2] above, among which,

[0018] The aforementioned inner molding body is resin-molded onto the outer side of the aforementioned tubular body while the tubular body is positioned.

[0019] The outer molded body is resin molded on the outside of the inner molded body while the inner molded body is positioned.

[0020] [4] According to the wire harness described in [1] above, among which,

[0021] The aforementioned trunk line has a pair of trunk conductors.

[0022] The aforementioned branch line has a pair of branch conductors.

[0023] The aforementioned conductor connection is a pair of conductor connection parts that electrically connect the aforementioned pair of main conductors on the upstream side to the aforementioned pair of main conductors and the aforementioned pair of branch conductors on the downstream side.

[0024] [5] According to the wire harness described in [1] above, among which,

[0025] The aforementioned conductor connection portion electrically connects the upstream main conductor to the downstream main conductor and the aforementioned branch conductor by crimping.

[0026] [6] According to the wire harness described in [5] above, among which,

[0027] The aforementioned conductor connection part is a sleeve for straight-line connection.

[0028] [7] According to the wire harness described in [2] above, wherein,

[0029] The aforementioned tubular body is a heat-shrinkable tube.

[0030] [8] According to the wire harness described in [7] above, wherein,

[0031] Furthermore, it includes an adhesive that fills the gap between the inner surface of the heat shrink tube and the conductor connection portion and its surrounding area.

[0032] [9] According to the wire harness described in [4] above, among which,

[0033] The downstream trunk line and the aforementioned multiple branch lines are each connected to a plug connector at their respective ends on the side opposite to the aforementioned branch.

[0034]

[10] According to the wire harness described in [9] above, wherein,

[0035] The mating portion of the aforementioned plug connector is oriented in a direction orthogonal to the length direction of the aforementioned branch line.

[0036]

[11] A lighting device, comprising:

[0037] The wire harness described in [9] or

[10] above; and

[0038] Multiple lighting fixtures are equipped with multiple socket connectors that can be connected to the aforementioned plug connectors.

[0039] According to the present invention, the configuration freedom of connected objects can be increased. Attached Figure Description

[0040] Figure 1 This is a top view showing a schematic structural example of a lighting device according to an embodiment of the present invention.

[0041] Figure 2A An example showing the external shape of a branch is provided, in which... Figure 2A (a) is a top view. Figure 2A (b) is the left-side view. Figure 2A (c) is the right-side view.

[0042] Figure 2B An example showing the external shape of a branch is provided, in which... Figure 2B (d) is the main view. Figure 2B (e) is the rear view. Figure 2B (f) is the bottom view.

[0043] Figure 3 yes Figure 2B (d) CC line section view.

[0044] Figure 4 (a) is a three-dimensional diagram illustrating the connection method of conductors. Figure 4 (b) is Figure 4 (a) DD line section view.

[0045] Figure 5 An example of the external shape of an inner molded body is shown, wherein, Figure 5 (a) is a top view. Figure 5 (b) is the front view.

[0046] Figure 6 This is a top view showing an example of the plug connector of Modified Example 1.

[0047] Explanation of reference numerals in the attached figures

[0048] 1…Wire harness; 2, 2A~2C…Trunk cable; 3…Branch section; 3a…Trunk cable retainer; 3b…Branch cable retainer; 4…Branch cable; 5A, 5B…Plug connector; 20…Insulated wire; 21…Trunk conductor; 22…Insulator; 23…Sheath; 30…Sleeve for straight connection; 30a…First opening; 30b…Second opening; 30c…Wire fastener; 30d, 30e…Crimping part; 3 1…heat shrink tubing; 32…inner molded body; 32a…positioning hole; 32b…positioning protrusion; 32c…groove; 33…outer molded body; 33a…protrusion; 33b…mounting hole; 40…insulated wire; 41…branch conductor; 42…insulator; 43…sheath; 50…fitting part; 100…lighting device; 110…power supply unit; 120…lighting fixture; 121…jack connector; A…upstream side; B…downstream side. Detailed Implementation

[0049] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in each drawing, structural elements having substantially the same function are labeled with the same reference numerals, and repeated descriptions thereof are omitted.

[0050] [Implementation Method]

[0051] Figure 1 This is a top view illustrating a schematic structural example of a lighting device according to an embodiment of the present invention. The lighting device 100 includes: a power supply unit 110, a plurality (N) of lighting fixtures 120, and a wiring harness 1 for supplying power from the power supply unit 110 to the plurality of lighting fixtures 120. Here, A is designated as the upstream side, and B as the downstream side. The power supply unit 110 is an example of a power supply device or an upstream device. The lighting fixtures 120 are examples of connected objects or downstream devices. N is, for example, 40, but can also be 2.

[0052] The wiring harness 1 includes: a main cable 2A connected to the power supply unit 110; multiple (N-2) main cables 2B sequentially connected to the main cable 2A; a main cable 2C connected to the main cable 2B at the downstream end of the multiple main cables 2B; multiple (N-1) branch sections 3, one for each of the multiple branch sections on the main cables 2A, 2B, and 2C; multiple (N-1) branch cables 4 branching from the multiple branch sections 3; and multiple (N) plug connectors 5A, located at the ends of the main cable 2C at the downstream end of the B and the multiple branch cables 4 on the side opposite to the branch section 3, for connection to multiple lighting fixtures 120. Furthermore, when referring collectively to the main cables 2A, 2B, and 2C, they are hereinafter referred to as main cable 2. There are usually two or more branch sections 3, but there can also be one. Main cable 2 is an example of a main line. Branch cable 4 is an example of a branch line.

[0053] As in existing examples, if a structure is used to directly connect the lighting fixture 120 to the main cable 2 via a waterproof socket, it is impossible to place the lighting fixture 120 away from the main cable 2, and the placement of the lighting fixture 120 is restricted by the waterproof socket. Therefore, this embodiment adopts a structure that connects the lighting fixture 120 to the main cable 2 via a branch cable 4. As a result, the lighting fixture 120 can be placed relative to the main cable 2 at any position (e.g., away from or close to the main cable 2) and in any orientation (e.g., parallel to or perpendicular to the main cable 2), thereby increasing the freedom of placement of the lighting fixture 120.

[0054] As multiple trunk cables 2B, cables of the same length can be used. For example, the total length of the trunk cable 2B can be set to be slightly longer than the total length of the lighting fixture 120. This allows the lighting fixture 120 to be arranged parallel to the trunk cable 2B. Alternatively, as multiple trunk cables 2B, cables of different lengths can also be used. Furthermore, the total length of the trunk cable 2C at the downstream end B can be set to the sum of the total length of the trunk cable 2B and the total length of the branch cable 4. This allows for... Figure 1 The imaginary line shown is the plug connector 5A side of the trunk cable 2C. Figure 1 As shown by the solid line, the trunk cable 2C is configured to face the same direction as the branch cable 4, allowing the trunk cable 2C to be handled in the same way as the branch cable 4.

[0055] The trunk cable 2 and branch cable 4 in this embodiment are, for example, a two-core power cable with a pair of power lines. The detailed structure of the trunk cable 2 and branch cable 4 in this embodiment will be described later. Furthermore, as shown below, the trunk cable 2 and branch cable 4 can be cables with a core wire structure corresponding to the connected object.

[0056] (i) A power cable having a grounding wire and a pair of power lines

[0057] (ii) A power cable with three power cords

[0058] (iii) Signal cables with two or more signal lines

[0059] (iv) Cables with 3 or more cores that have power and signal lines

[0060] Alternatively, the main cable 2 and branch cable 4 can also be insulated wires that separate multiple conductors and cover their outer perimeter with a single insulator. Cables and insulated wires are an example of wires.

[0061] The plug connector 5A can use a connector with a number of poles corresponding to the number of cores in the main cable 2C and the branch cable 4. In this embodiment, the plug connector 5A uses a connector with a number of poles corresponding to the number of cores (two-core) in the main cable 2C and the branch cable 4. Furthermore, when waterproofing is required, the plug connector 5A preferably has a waterproof sealing ring in the mating portion 50. This provides higher waterproof performance (e.g., IEC standard IPX7 (water will not seep in even when temporarily submerged under certain water pressure), allowing the wiring harness 1 to be installed outdoors in locations where watering is required (e.g., plant cultivation factories). Alternatively, the waterproof performance can also be IEC standard IPX6 (unaffected by strong jets of water from all directions) or IPX5 (unaffected by jets of water from all directions).

[0062] As a lighting fixture 120, a single-sided powered straight-tube LED lamp can be used, for example. The straight-tube LED lamp includes: a cylindrical tube component formed of acrylic resin, polycarbonate resin, etc.; a pair of cap-shaped cover components blocking both ends of the tube component; a circuit board housed inside the tube component and on which multiple LED elements are mounted along its length; and a socket connector 121 disposed in one of the cover components and connected to the plug connector 5A. An LED element is an example of a light-emitting element. Furthermore, the light-emitting element is not limited to LED elements; it can also be a fluorescent lamp, an incandescent bulb, an organic EL, an inorganic EL, etc. The number of light-emitting elements can be one for one branch cable 4 or one trunk cable 2C. Furthermore, where waterproofing is required, the socket connector 121 preferably has a waterproof sealing ring at the mating part. This allows for higher waterproof performance (e.g., IPX7 according to IEC standards). Alternatively, the waterproof performance can also be IPX6, IPX5, etc., according to IEC standards.

[0063] The power supply unit 110 can use a power supply corresponding to the straight tube LED lamp of the lighting fixture 120. Specifically, if the straight tube LED lamp has a built-in converter that converts AC power to DC power, then AC power (e.g., AC100V, AC200V, etc.) can be used as the power supply unit 110. If the straight tube LED lamp does not have the built-in converter, then DC power (e.g., DC12V, DC24V, etc.) can be used as the power supply unit 110.

[0064] Furthermore, the downstream device connected to the main cable 2C and multiple branch cables 4 is not limited to the lighting fixture 120, but may also be the device shown below.

[0065] (i) Equipment that requires a power supply

[0066] (ii) Equipment that requires power supply and needs to transmit and receive signals

[0067] (iii) Devices that do not require a power supply but can transmit and receive signals

[0068] As an upstream device connected to the upstream side A of the trunk cable 2A, it is not limited to the power supply unit 110, but may also be the device shown below.

[0069] (i) Equipment that supplies power

[0070] (ii) Equipment that supplies power and transmits / receives signals

[0071] (iii) Equipment that transmits and receives signals but is not powered.

[0072] Signals transmitted and received between upstream and downstream devices include, for example, control signals and drive signals.

[0073] (The appearance and shape of the branch)

[0074] Figure 2A , Figure 2B An example showing the external shape of branch 3 is provided. Figure 2A (a) is a top view. Figure 2A (b) is the left-side view. Figure 2A (c) is the right-side view. Figure 2B (d) is the main view. Figure 2B (e) is the rear view. Figure 2B (f) is a bottom view. Branch section 3 consists of a trunk cable retaining section 3a formed along the trunk cable 2B and a branch cable retaining section 3b formed along the branch cable 4, and has an overall T-shape, as described later. Figure 3As described, it includes: a pair of heat shrink tubes 31, an inner molded body 32 formed of resin on the outside of the pair of heat shrink tubes 31, and an outer molded body 33 formed of resin on the outside of the inner molded body 32. The shape of the outermost outer molded body 33 forms the appearance shape of the branch 3. A trunk cable 2B (or trunk cable 2A) is led out from the outer molded body 33 to the upstream side A, a trunk cable 2B (or trunk cable 2C) is led out from the outer molded body 33 to the downstream side B, and a branch cable 4 is led out from the outer molded body 33 in a direction that intersects with the trunk cable 2B.

[0075] In this embodiment, the lead-out angle θ of the branch cable 4 relative to the main cable 2B (2C) on the downstream side B is set to 90°, but it can also be less than 90° (e.g., 45°) or more than 90° (e.g., 135°). Alternatively, the branch cable 4 can be led out parallel to the main cable 2B (2C) (θ = 0°). In this case, the branch cable 4 can be in contact with the main cable 2B (2C) or separated.

[0076] The two ends 3c and 3d of the trunk cable retaining part 3a are formed into a tapered shape to prevent the wall thickness of the inner molded body 32 and the outer molded body 33 from becoming locally thicker. As a result, when the inner molded body 32 and the outer molded body 33 are formed by injection molding or the like, it becomes easier to inject the molten resin into the mold cavity.

[0077] A protrusion 33a extends near the root of the generally T-shaped outer forming body 33, and a mounting hole 33b is formed in the protrusion 33a. A cable tie can be passed through the mounting hole 33b and used to mount the branch 3 to a frame (e.g., the frame supporting the lighting fixture 120). Alternatively, the protrusion 33a and mounting hole 33b can be provided in other locations, or in more than two locations. Alternatively, the protrusion 33a and mounting hole 33b may not be provided.

[0078] (Internal structure of the branch)

[0079] Figure 3 yes Figure 2B (d) CC-line cross-sectional view. Main cable 2 is, for example, a two-core power cable consisting of a sheath 23 covering a pair of insulated wires 20. Branch cable 4 is, for example, a two-core power cable consisting of a sheath 43 covering a pair of insulated wires 40. As described later... Figure 4 As shown, the insulated wire 20 of the trunk cable 2 includes: a trunk conductor 21, and an insulator 22 covering the outer periphery of the trunk conductor 21. (As described later...) Figure 4As shown, the insulated wire 40 of the branch cable 4 includes: a branch conductor 41 and an insulator 42 covering the outer periphery of the branch conductor 41. The main conductor 21 and the branch conductor 41 can be, for example, stranded wires made of multiple stranded metal wires. Alternatively, single wires can be used instead of stranded wires for the main conductor 21 and the branch conductor 41. The insulators 22 and 42 are formed, for example, of resin materials such as polyvinyl chloride and polyethylene. The sheaths 23 and 43 are formed, for example, of resin materials such as polyvinyl chloride and polyethylene.

[0080] Branch section 3 includes: a pair of straight-connect sleeves 30, which electrically connect the main conductors 21 of a pair of insulated wires 20 constituting the main cable 2 on the upstream side A to the main conductors 21 of a pair of insulated wires 20 constituting the main cable 2 on the downstream side B and the branch conductors 41 of a pair of insulated wires 40 constituting the branch cable 4; a pair of heat-shrinkable tubes 31, which respectively cover the pair of straight-connect sleeves 30 and their peripheries; an inner molded body 32, which is formed with resin on the outside of the heat-shrinkable tubes 31 when the pair of heat-shrinkable tubes 31 are positioned relative to the inner molded body by a mold; and an outer molded body 33, which is formed with resin on the outside of the inner molded body 32 when the inner molded body 32 is positioned relative to the outer molded body by a mold. The straight-connect sleeves 30 are an example of a conductor connection portion. The heat-shrinkable tubes 31 are an example of a tubular body. The heat-shrinkable tubes 31, the inner molded body 32, and the outer molded body 33 are an example of a covering portion formed of insulating material. In addition, the inner molded body 32 and the outer molded body 33 can also be formed from a single molded body.

[0081] The straight-line connection sleeve 30 can be, for example, a bare crimping sleeve for copper wire according to JIS C2806. The straight-line connection sleeve 30 is formed, for example, of a soft conductive material (e.g., oxygen-free copper). The straight-line connection sleeve 30 directly connects and crimps the main conductor 21 of the upstream side A to the main conductor 21 and branch conductor 41 of the downstream side B, thereby electrically connecting the main conductor 21 of the upstream side A to the main conductor 21 and branch conductor 41 of the downstream side B. Alternatively, other sleeves that electrically connect conductors by crimping, or connecting components that electrically connect conductors by welding, fusion, etc., can be used instead of the straight-line connection sleeve 30.

[0082] The heat shrink tube 31 is formed from polyethylene resin, polyolefin resin, fluoropolymer resin, etc., and shrinks radially upon heating. The heat shrink tube 31 can also be a commercially available double-layered heat shrink tube with a hot melt adhesive layer on the inner side. In this case, by heating the heat shrink tube with the hot melt adhesive, the heat shrink tube shrinks radially, and the hot melt adhesive enters the gap between the inner surface of the heat shrink tube and the straight-line sleeve 30 and its surroundings (insulated wires 20, 40 and conductors 21, 41, etc.), filling the gap with the hot melt adhesive, thereby achieving higher waterproof performance (e.g., IPX7 according to IEC standards). Furthermore, instead of the heat shrink tube with the hot melt adhesive, methods such as applying hot melt adhesive to the straight-line sleeve 30 and its surroundings before wrapping the heat shrink tube 31, or pre-curing a water-resistant adhesive (such as an instant adhesive) before wrapping the heat shrink tube 31, can also be used. Considering the control of the wall thickness of the hot melt adhesive and the adhesion between the hot melt adhesive and the heat shrink tube 31 (which is more difficult for fluoropolymers), the aforementioned heat shrink tube with hot melt adhesive is preferred. The hot melt adhesive and water-resistant adhesive are examples of adhesives used to fill the gaps between the inner surface of the heat shrink tube and the conductor connection portion and its periphery. Alternatively, as an example of a tubular body, a tubular molded body formed of resin can be used instead of the heat shrink tube 31, and it can be coated with an insulating adhesive such as hot melt adhesive or wrapped with insulating tape.

[0083] The inner molded body 32 may also be formed from a soft resin material (e.g., soft polyvinyl chloride, polyethylene, etc.) by resin molding (e.g., injection molding, compression molding, extrusion molding, calendering, transfer molding, lamination molding, etc.).

[0084] The outer molded body 33 may also be formed from a soft resin material (e.g., soft polyvinyl chloride, polyethylene, etc.) by resin molding (e.g., injection molding, compression molding, extrusion molding, calendering, transfer molding, lamination molding, etc.).

[0085] By making the inner molded body 32 and the outer molded body 33 from a soft resin material, the branch portion 3 can be made flexible, which can alleviate the load on the trunk cable 2 and the branch cable 4 when laying them. In addition, by forming the inner molded body 32 and the outer molded body 33 by injection molding, it is possible to stably and mass-produce molded bodies of the same quality.

[0086] (Methods for connecting conductors)

[0087] Figure 4 (a) is a three-dimensional diagram illustrating the connection method of conductors. Figure 4 (b) is Figure 4(a) DD-line cross-sectional view. The straight-line connection sleeve 30 is cylindrical and includes: a first opening 30a for inserting the main conductor 21 of the upstream side A into one side; a second opening 30b for inserting the main conductor 21 and branch conductor 41 of the downstream side B into the other side; and a wire fixing member 30c disposed in the center. The straight-line connection sleeve 30 inserts the main conductor 21 of the upstream side A into the first opening 30a until its front end abuts against the wire fixing member 30c, and inserts the main conductor 21 and branch conductor 41 of the downstream side B into the second opening 30b until their front ends abut against the wire fixing member 30c. In the state where the main conductor 21 of the upstream side A and the main conductor 21 and branch conductor 41 of the downstream side B are straight-line connected, the crimping portion 30d of the first opening 30a and the crimping portion 30e of the second opening 30b are crimped together. Therefore, the main conductor 21 of the upstream side A can be easily electrically connected to the main conductor 21 and branch conductor 41 of the downstream side B.

[0088] (Structure of the inner shaped body)

[0089] Figure 5 An example of the external shape of the inner molded body 32 is shown. Figure 5 (a) is a top view. Figure 5 (b) is the front view. The inner molded body 32 includes: multiple positioning holes 32a for positioning pins to pass through during resin molding; multiple positioning protrusions 32b for positioning the inner molded body 32 during resin molding of the outer molded body 33; and two grooves 32c. By providing the grooves 32c, the straight-line mating sleeve 30, on which the heat shrink tube 31 is mounted, can... Figure 5 In (b), the position is set so that it does not move in the up and down directions.

[0090] (Manufacturing method of wire harness)

[0091] Next, an example of the manufacturing method of wire harness 1 will be described.

[0092] (1) Preparation of trunk cables and branch cables

[0093] Prepare the upstream trunk cable 2A, multiple trunk cables 2B connected to the trunk cable 2A, the downstream trunk cable 2C, and multiple branch cables 4. At this time, expose both ends of the trunk conductor 21 of the insulated wire 20 of the trunk cable 2 and both ends of the branch conductor 41 of the insulated wire 40 of the branch cable 4.

[0094] (2) Connection of conductors based on straight-line butt sleeves

[0095] The front end of the main conductor 21 of the upstream side A is inserted into the first opening 30a of the straight-line connection sleeve 30 until it abuts against the wire fixing member 30c. The front ends of the main conductor 21 and branch conductor 41 of the downstream side B are inserted into the second opening 30b of the straight-line connection sleeve 30 until they abut against the wire fixing member 30c. Next, the crimping portion 30d of the first opening 30a and the crimping portion 30e of the second opening 30b are crimped together. Thus, the main conductor 21 of the upstream side A is electrically connected to the main conductor 21 and branch conductor 41 of the downstream side B. The connection of conductors based on a pair of straight-line connection sleeves 30 is performed for one branch 3 as described above, and the conductor connection is performed in the same way for other branch 3.

[0096] (3) Installation of heat shrink tubing

[0097] A heat shrink tube 31 with hot melt adhesive on its inner side is used to cover the straight-line coupling sleeve 30 and its periphery. The heat shrink tube 31 is heated to shrink radially, and the heat shrink tube 31 is used to wrap the straight-line coupling sleeve 30 and its periphery with hot melt adhesive. As described above, a pair of heat shrink tubes 31 with hot melt adhesive on their inner sides are installed on a pair of straight-line coupling sleeves 30 and their periphery for one branch 3, and the same applies to other branches 3.

[0098] (4) Positioning of heat shrink tubing

[0099] A pair of heat-shrinkable tubes 31, which are installed on a pair of straight-line connecting sleeves 30 connected to the main cable 2 and the branch cable 4, are positioned on the lower mold of the inner forming mold (not shown). At this time, as... Figure 3 As shown, a locating pin is inserted into a hole formed in the lower mold of the inner molding die corresponding to the locating hole 32a. The locating pin positions a pair of heat shrink tubes 31 and a pair of insulated wires 40 of the branch cable 4 relative to the lower mold of the inner molding die. In addition, a hole for inserting the locating pin is also formed in the upper mold of the inner molding die.

[0100] (5) Formation of the inner molded body

[0101] For example, the inner molded body 32 is formed by injection molding. That is, the lower mold of the inner molded body mold is aligned with the upper mold, and molten first resin (e.g., soft polyvinyl chloride) is injected into the mold cavity (first space) between the lower and upper molds of the inner molded body mold. After the first resin cools and solidifies, the solidified molded product is demolded from the inner molded body mold. Thus, the inner molded body 32 is formed with the main cable 2 leading upstream to A and the main cable 2 and branch cable 4 leading downstream to B. The locating pin is pulled out from the inner molded body mold. As described above, one inner molded body 32 is formed for one branch 3, and the same inner molded body 32 is formed for other branches 3.

[0102] (6) Formation of the outer shaping body

[0103] For example, an outer molded body 33 is formed on the outside of an inner molded body 32 by injection molding. That is, the inner molded body 32 is positioned on the lower mold of an outer molded body mold, with the lower mold aligned with the upper mold. At this time, the inner molded body 32 is positioned relative to the outer mold by a positioning protrusion 32b formed on the inner molded body 32. Furthermore, in Figure 3 and Figure 5 The positioning protrusion 32b is provided only at the bottom of the paper in (a) because the molten second resin is injected from the sprue located above, and the inner molded body 32 is squeezed downward. Therefore, depending on the location of the sprue, the positioning protrusion 32b can also be provided at other locations.

[0104] Next, molten second resin (e.g., flexible polyvinyl chloride) is injected into the mold cavity (second space) between the lower and upper molds of the outer molding body mold. After the second resin cools and solidifies, the solidified molded article is demolded from the outer molding body mold. Thus, the outer molding body 33 is formed with the main cable 2 leading upstream to side A and the main cable 2 and branch cable 4 leading downstream to side B. As described above, one outer molding body 33 is formed for one branch 3, and the same applies to other branch 3.

[0105] (7) Connecting the plug connector

[0106] Connect plug connectors 5A to the ends of the main cable 2C on the downstream side B and the multiple branch cables 4. Manufacture the wire harness 1 as described above. In use, connect the main cable 2A on the upstream side A to the power supply unit 110.

[0107] Furthermore, the order of the above operations can be changed. For example, during the preparation of the main cable 2C and branch cables 4, plug connectors 5A can be connected to the ends of the main cable 2C and the multiple branch cables 4.

[0108] (Effects of the implementation method)

[0109] According to this embodiment, the following effects are achieved.

[0110] (a) The lighting fixture 120 is connected to the main cable 2 via the branch cable 4, thereby increasing the flexibility of the configuration of the lighting fixture 120.

[0111] (b) The main conductor 21 of the upstream side A is connected to the main conductor 21 and branch conductor 41 of the downstream side B using a straight-line connection sleeve 30. The straight-line connection sleeve 30 and its periphery are covered with heat-shrinkable tubing 31 using hot melt adhesive. Further coverage is achieved by a double-molded body consisting of an inner molded body 32 and an outer molded body 33. This improves the waterproofness of the branch portion 3, resulting in higher waterproof performance (e.g., IPX7 according to IEC standards). Alternatively, depending on the application, waterproof performance lower than IPX7, such as IPX6 or IPX5 according to IEC standards, may be used, or there may be almost no waterproof performance.

[0112] (c) It can supply power to multiple lighting fixtures 120 through trunk cables 2B and 2C branching from a trunk cable 2A and branch cables 4.

[0113] (Variation Example 1)

[0114] Figure 6 This is a top view showing an example of the plug connector of Modified Example 1. In the above embodiment, a plug connector 5A is used where the orientation of the mating portion 50 is the same as the length direction of the branch cable 4. However, the plug connector 5B of Modified Example 1 is an L-shaped plug connector, and the orientation of the mating portion 50, which is mated to the socket connector 121 of the lighting fixture 120, is orthogonal to the length direction of the branch cable 4. Therefore, the lighting fixture 120 can be arranged parallel to the main cable 2 even without bending the branch cable 4.

[0115] Similar to plug connector 5A, L-type plug connector 5B also uses a connector with a number of poles (two poles) corresponding to the number of cores (two cores) of the main cable 2C and the branch cable 4. Furthermore, where waterproofing is required, plug connector 5B preferably has a waterproof sealing ring in the mating portion 50. This allows for higher waterproofing performance (e.g., IPX7 according to IEC standards). Alternatively, waterproofing performance can also be IPX6, IPX5, etc., according to IEC standards.

[0116]

Example

[0117] A waterproof performance test was conducted on the heat shrink tube 31 constituting branch 3 with and without hot melt adhesive. The test results are shown in Table 1.

[0118] (Test subjects)

[0119] The following Examples 1 and 2 were used as test subjects. In Example 1, a commercially available heat shrink tube (with a hot melt adhesive layer on the inside) was used as the heat shrink tube 31. In Example 2, a heat shrink tube (without an adhesive layer on the inside) was used as the heat shrink tube 31. Furthermore, in Examples 1 and 2, an inner molded body 32 and an outer molded body 33 were respectively formed by injection molding.

[0120] (Judgment Criteria)

[0121] After conducting tests for each level of waterproof performance according to IEC standards, a voltage of 1500V was immediately applied between the electrodes for 1 minute, and the presence or absence of insulation failure was used as the judgment result. In the judgment results in Table 1, 〇 indicates no insulation failure (good), and × indicates the presence of insulation failure (bad).

[0122] Table 1

[0123] Table 1

[0124]

[0125] (Experimental Results)

[0126] It is evident that Example 1, which uses a heat shrink tube with hot melt adhesive as the heat shrink tube 31, meets the IEC standards IPX1 to IPX7. It is evident that Example 2, which uses a heat shrink tube without adhesive as the heat shrink tube 31, meets the IEC standards IPX1 and IPX2. That is, it is evident that by providing hot melt adhesive on the inside of the heat shrink tube 31, the waterproof performance is significantly improved.

[0127] The embodiments of the present invention have been described above, but the embodiments of the present invention are not limited to the above embodiments and can be implemented in various modifications.

Claims

1. A wire harness comprising: a trunk line extending from an upstream side to a downstream side; a plurality of branches, each branching off from the trunk line; and a plurality of branch lines branching off from the plurality of branches. in, The trunk line has a trunk conductor. The branch line has a branch conductor. The branch section includes: a conductor connection portion that electrically connects the upstream main conductor to the downstream main conductor and the branch conductor; and a covering portion that covers the conductor connection portion and its surrounding area with an insulating material.

2. The wire harness according to claim 1, wherein, The covering portion includes: A tubular body that covers the conductor connection portion and its periphery; The inner molded body, with resin molded on the outer side of the tubular body; and The outer molded body is formed on the outside of the inner molded body.

3. The wire harness according to claim 2, wherein, The inner molding body is formed on the outer side of the tubular body while the tubular body is positioned. The outer molded body is formed on the outside of the inner molded body while the inner molded body is positioned.

4. The wire harness according to claim 1, wherein, The trunk line has a pair of trunk conductors. The branch line has a pair of branch conductors. The conductor connection is a pair of conductor connection parts that electrically connect the pair of main conductors on the upstream side to the pair of main conductors and the pair of branch conductors on the downstream side respectively.

5. The wire harness according to claim 1, wherein, The conductor connection portion electrically connects the upstream main conductor to the downstream main conductor and the branch conductor by crimping.

6. The wire harness according to claim 5, wherein, The conductor connection part is a sleeve for straight-line connection.

7. The wire harness according to claim 2, wherein, The tubular body is a heat-shrinkable tube.

8. The wire harness according to claim 7, wherein, It further includes an adhesive that fills the gap between the inner surface of the heat shrink tube and the conductor connection portion and its periphery.

9. The wire harness according to claim 4, wherein, The downstream trunk line and the plurality of branch lines are connected to plug connectors at their respective ends on the side opposite to the branch.

10. The wire harness according to claim 9, wherein, The mating portion of the plug connector is oriented in a direction orthogonal to the length direction of the branch line.

11. A lighting device, wherein, have: The wire harness as described in claim 9 or 10; and Multiple lighting fixtures, each having multiple socket connectors that connect to the multiple plug connectors.

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