Injection molded wiring harness and molding method

Abstract

The present invention relates to an injection-molded wiring harness and molding method. The wiring harness comprises a terminal and at least one conductor. One end of the terminal is connected to the electrical circuit of an electrical device, and the other end is connected to the conductor. The wiring harness is provided with an injection-molded protective layer covering the conductor, as well as at least one injection-molded positioning device for securing the wiring harness and / or a sealing device for waterproofing. The present invention can reduce manual labor, improve the consistency of wiring harness products, reduce production costs, and extend the service life of the wiring harness.

Description

Technical Field

[0001] The present invention relates to the technical field of wire harnesses, and in particular to an injection-molded wire harness and a molding method. Background Art

[0002] In the field of electrical connection, wiring harness serves as a bridge connecting electrical circuits, connecting power sources and electrical appliances, as well as between various electrical appliances for data exchange. It is an essential and important component in automobiles, airplanes, ships, various household appliances and equipment.

[0003] The construction methods and materials of wire harnesses vary greatly, but the main structure is composed of cables, terminals, sheaths, fixing devices, waterproof devices, etc., among which the cables are composed of conductors and an insulating layer wrapped around the conductor. The current processing technology of wire harnesses is relatively complicated, including cutting, stripping, crimping terminals, welding, threading pipes, inserting blind plugs, inserting terminals, inserting sheaths, sub-packaging, wiring, rubber coating, branch fixing, installation of positioning devices, installation of components, conduction, appearance inspection, packaging and other processes. Among them, sub-packaging, wiring, rubber coating, branch fixing, installation of positioning devices and installation of components are the main working hours occupied by wire harness production, and there is currently no automated production equipment. All operations are performed manually, with a high failure rate, high production costs, and the inability to guarantee product consistency. This has become a bottleneck restricting the development of the wire harness industry. In traditional wire harness processing technology, there are two ways to install the positioning device of the wire harness, namely, fixing with tape and fixing with cable ties, but both methods have disadvantages such as inaccurate installation dimensions and easy falling off of the positioning device. In traditional wire harness processing technology, the sealing device of the wire harness is made of rubber, which needs to be stretched out in advance during installation to ensure that the cable can pass through and be fixed. In order to ensure sealing, putty and sealant must be added between the sealing device and the cable. The process is complicated and can easily cause damage to the sealing device, making the sealing function ineffective.

[0004] In addition, the various parts of the traditional wiring harness are not tightly combined, including the cable and the protective sleeve on it, the cable connected to the sleeve through the terminal, the positioning device fixed by tape or cable ties, and the waterproof device attached to the wiring harness through the elasticity of the rubber part. During long-term use, the connections between the various parts will gradually fail, resulting in wear of the cable and the protective sleeve, separation of the cable and the sleeve, inaccurate position or fall-off of the positioning device, and damage or fall-off of the waterproof device, resulting in the loss of the function of each part, which will cause the wiring harness to fail, and in serious cases, cause accidents.

[0005] Therefore, the wire harness industry is in urgent need of a new method that can simplify the wire harness assembly production process, reduce manual operations, improve product consistency, and reduce product production costs.

[0006] To this end, Chinese invention patent application CN 104149770A discloses an injection-molded anti-lock brake system sensor harness. This invention adds injection-molded locating parts to the existing signal transmission cable. However, this invention only addresses anti-lock brake system sensor harnesses and has limitations. This invention still requires the purchase of finished cables and then processing them into the main harness body, which does not save harness costs. This invention does not protect the cables. After installation and use, the cable insulation can be damaged by vibration and friction at the mounting point. In severe cases, this can cause a short circuit and lead to a fire. Furthermore, the added injection-molded parts in this invention have a single function and cannot meet other complex wiring harness requirements.

[0007] Therefore, in the field of wire harness technology, there is an urgent need for a wire harness and forming method with simple production process, high wire harness dimensional accuracy and long service life, which can reduce wire harness cost, increase waterproof level, improve production efficiency, reduce product defect rate and extend wire harness service life. Summary of the Invention

[0008] In response to the above-mentioned technical problems and to overcome the shortcomings of the prior art, the present invention addresses the technical problem of providing a new injection-molded wire harness and molding method that can significantly simplify the wire harness processing process, reduce manual operations, improve product consistency, increase the waterproof rating, and reduce product production costs. Complex wire harnesses can be processed and molded in one go, improving production efficiency and making the wire harness more widely applicable. Furthermore, wire harnesses requiring sealing can be molded in one go, increasing the sealing performance of the wire harness, reducing the use of materials such as mortar and sealant, and extending the service life of the waterproof area, significantly improving safety performance.

[0009] The object of the present invention is achieved through the following technical solutions:

[0010] The present invention provides an injection-molded wiring harness, which includes a terminal and at least one conductor, one end of the terminal being connected to the electrical circuit of an electrical device, and the other end of the terminal being connected to the conductor. The wiring harness is provided with an injection-molded protective layer covering the outside of the conductor, and at least one injection-molded positioning device for fixing the position of the wiring harness and / or a sealing device for waterproofing. It should be noted that the wiring harness of the present invention is different from the traditional wiring harness, and can use cables with an insulating layer, or can directly use conductors for injection molding. The processing forms of the conductors can also be various, such as cutting of coiled conductors, cutting of copper foil, printing of conductors, 3D printing, etc. The wiring harness can be selected and optimized according to different usage environments, which can save raw materials to a greater extent, reduce processing time, and improve product quality.

[0011] The injection-molded wiring harness of the present invention has various parts that are connected together by heating and melting and then cooling and molding. It can be said to be an integrated structure. There is no mutual wear between the parts, the relative positioning dimensions are also accurate, the service life is greatly improved compared with traditional wiring harnesses, and safety can also be guaranteed.

[0012] Preferably, an insulating layer is further provided on the outside of the conductor, and a protective layer is injection-molded outside the insulating layer.

[0013] Preferably, the positioning device includes a first fixing device connected to the wire harness and an assembly device connected to the mounting end of the wire harness, and the assembly device is connected to the first fixing device.

[0014] It's important to note that when installing a wiring harness, if it exceeds a certain length, a retaining device is typically used to connect it to the mounting end, such as an engine, sheet metal frame, or other pipeline. Without a retaining device, the wiring harness will shift relative to the mounting end, increasing wear and tear. Furthermore, this movement can produce unusual noises, affecting the user experience of vehicles, aircraft, ships, or various household appliances.

[0015] Preferably, the first fixing device is a cylindrical structure, and the inner wall of the cylindrical structure cooperates with the outer surface of the protective layer and is wrapped around the outer surface of the protective layer.

[0016] The cylindrical structure is used to enhance the strength of the fixing device and prevent the positioning device from falling off from the wiring harness due to stress.

[0017] Preferably, the assembly device is a columnar structure, and the outer periphery of the columnar structure has a reverse tooth structure.

[0018] The inverted tooth structure is used to prevent the columnar structure from falling off from the mounting hole when the columnar structure matches the mounting hole of the mounting end.

[0019] Preferably, the assembly device has a clip-like structure.

[0020] Preferably, the clip-like structure has a groove, and barbs are provided on both side walls of the groove. The barbs are provided in the groove so that when the clip-like structure matches the sheet metal edge of the mounting end, it can clamp the sheet metal edge and prevent the clip-like structure from falling off the sheet metal edge.

[0021] Preferably, the assembly device has a circular ring structure or a C-shaped ring structure. The circular ring structure or the C-shaped ring structure is to prevent the assembly device from falling off from other pipelines at the installation end when the assembly device is matched with the other pipelines.

[0022] Preferably, the positioning device is a plastic part processed by injection molding. Since the positioning device is rigidly connected to the mounting end, if a rubber part is used, the deformation is large and the connection will be loose, so a plastic part with good hardness and elasticity is used.

[0023] Preferably, the sealing device includes a second fixing device connected to the wiring harness and a waterproof device, and one end of the waterproof device is connected to the second fixing device.

[0024] Preferably, the second fixing device is a cylindrical structure, the inner wall of which cooperates with the outer surface of the protective layer and wraps around the outer surface of the protective layer. The cylindrical structure is to strengthen the fixing device and prevent the sealing device from falling off the wiring harness due to force.

[0025] Preferably, the sealing device is a rubber part processed by injection molding. Since the sealing device needs to seal the sealed end of the wiring harness, the sealed end of the wiring harness is injection-molded with an elastic material such as a rubber part to prevent water from the external environment from entering the wiring harness and causing corrosion of the wiring harness conductors, which would seriously reduce the service life of the wiring harness and even cause safety accidents.

[0026] It should be noted that the sealed end of the wiring harness refers to the holes on the partition between the dry area and the wet area that the wiring harness will pass through during installation. In order to prevent water from the wet area from entering the dry area, a waterproof device on the wiring harness is required to cooperate with the holes on the partition to seal the connection. In addition, when the wiring harness is in a wet area, conductors will be exposed between the protective layer and the terminals of the wiring harness. A sealing device is required to seal and wrap the exposed conductors and terminals to prevent water from the external environment from corroding the conductors and terminals. In addition, when the sheath is in a wet area, a sealing device is required to seal the holes in the sheath to prevent water from entering the sheath and causing corrosion to the terminals and conductors.

[0027] Preferably, the wiring harness is further provided with at least one sheath for plugging into the electrical device, and the terminals are assembled in corresponding holes of the sheath.

[0028] Preferably, the sheath is integrally injection-molded onto at least the terminal.

[0029] The conductor is connected to the sheath through a connecting terminal. In order to ensure a firm connection between the conductor and the sheath, the conductor and the sheath can be fixed together by the protective layer when the protective layer is injection molded, thereby extending the service life of the wiring harness.

[0030] Preferably, the conductor is a solid conductor, a flat conductor, or a multi-strand conductor. Depending on the different use environments of the wiring harness, the conductor can have different structures.

[0031] Preferably, the terminal is connected to a solid conductor, a flat conductor, or a conductor of a multi-strand wire by crimping or welding.

[0032] Generally, when the conductor and the terminal are made of the same or similar materials, crimping is used. When the conductor and the terminal are made of significantly different materials, welding is used.

[0033] Preferably, the cross section of the conductive portion of the conductor is circular, elliptical, polygonal, wavy or special-shaped.

[0034] According to the structure of the conductor in the wiring harness, conductive parts with different cross-sectional areas can be selected to form a conductive loop.

[0035] Preferably, when there are more than two conductors and they belong to the same loop, the non-terminal side conductors are connected to form conductor connection points according to loop requirements by crimping or welding.

[0036] Preferably, the conductor connection point is integrally sealed by injection molding.

[0037] The conductor connection points described above can significantly reduce the use of conductor material, allowing current to be diverted to different conductors at appropriate locations. Due to the use of crimping or welding, stress on the conductors on both sides of the conductor connection points is relatively concentrated. This can cause stress during subsequent use, leading to breakage of the conductor connection points and loss of wiring harness functionality. Therefore, integral injection molding is required to wrap and protect the conductor connection points. Injecting integrally molded conductor connection points in humid areas also provides a waterproof seal.

[0038] The method for preparing the wiring harness of the present invention comprises the following steps:

[0039] (1) preparing semi-finished wire harnesses;

[0040] (2) placing the required raw materials into an injection molding device and drying them, and then placing the wire harness semi-finished product prepared in step (1) into an injection mold; or placing the wire harness semi-finished product prepared in step (1) into an injection mold, and then placing the required raw materials into an injection molding device and drying them.

[0041] (3) Start the injection molding equipment to heat and melt the raw materials and inject them into the injection mold for molding.

[0042] Preferably, when the prepared wire harness semi-finished product is a single conductor, the terminal is connected to the conductor using a crimping or welding device; and a protective layer or a positioning device or a sealing device is injection molded according to steps (2)-(3).

[0043] Preferably, when the prepared wire harness semi-finished product is more than one conductor, the terminal is connected to the conductor using a crimping or welding device; according to steps (2)-(3), a protective layer is first injection-molded to isolate multiple conductors, and then a positioning device or a sealing device is injection-molded.

[0044] Preferably, when the prepared wiring harness semi-finished product has more than two conductors and belongs to the same loop, the conductors are connected to form conductor connection points according to the loop requirements by crimping or welding; according to steps (2)-(3), the wiring harness protection device is first injection-molded, then the protective layer is injection-molded, and finally the positioning device or the sealing device is injection-molded.

[0045] Preferably, when the wiring harness semi-finished product is provided with a sheath, the terminals of the connecting conductors are inserted into the corresponding holes of the sheath before injection molding; or the wiring harness semi-finished product is injection molded first, and then the terminals of the connecting conductors are inserted into the corresponding holes of the sheath.

[0046] The semi-finished wire harness product is placed into an injection mold, and the sheath is integrally injection-molded onto at least the terminal.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The traditional design concept of wire harnesses is to purchase and process various raw materials such as cables, terminals, sheaths, fixtures, waterproof devices, tapes, and support troughs separately, and then assemble them into finished wire harnesses. This approach allows raw material manufacturers and wire harness manufacturers to divide the work and cooperate with each other, each doing its own job. However, the production process of this kind of production is particularly cumbersome, with many processing steps, a high defect rate in the production process, and it is difficult to guarantee the size and performance of the finished wire harness. The inventors of the present application have found that, except for conductors and terminals, the rest of the wire harness is basically plastic parts and rubber parts, and the current production process methods for plastic parts and rubber parts are mostly injection molding. Therefore, using the injection molding method of the present invention to process the wire harness protective layer, positioning device and waterproof device can reduce the cost of the wire harness, improve production efficiency, reduce the product defect rate and extend the service life of the wire harness.

[0049] 2. The wire harness of the present invention uses conductors that are directly injection molded, and the processing forms of the conductors can also be varied. They can be selected and optimized according to different wire harness usage environments, thus saving wire harness raw materials, reducing processing hours, and improving wire harness product quality to a greater extent. It also provides wire harness designers with more diverse design options, further optimizes wire harness costs, and improves wire harness product stability. The injection-molded protective layer of the present invention replaces the manual operation of sleeves and rubberized tape in traditional wire harnesses, and can achieve automated production. The more branches a wire harness has, the more working hours are saved. In addition, the protective layer produced by the injection molding process avoids the shortcomings of inaccurate dimensions and insufficient protection at the joints caused by manual rubberized tape operations, and can better guarantee the quality of wire harness products and extend the service life of the wire harness.

[0050] 3. The wiring harness of the present invention adopts an integral injection molding process. The protective layer, positioning device, sealing device and other components of the wiring harness can be tightly integrated. The waterproof effect of the wiring harness can reach the IP67 level. After the wiring harness undergoes salt spray tests, high and low temperature tests, vibration tests and aging tests, the mechanical and electrical properties between the wiring harness conductors and terminals are minimally affected, which can better ensure the quality of the wiring harness product and extend the service life of the wiring harness. At the same time, the injection molding materials are more diverse, and different injection molding materials can be selected according to different use environments, making the wiring harness more flexible and having better anti-vibration effect. It can be used in environments with relatively harsh vibration environments, significantly extending the service life of the wiring harness and improving the safety of the wiring harness.

[0051] 4. The wiring harness of the present invention can also use wires with an insulation layer. When the wiring harness has fewer loops, or the wires are longer and the sealing requirements are not high, using wires with an insulation layer can reduce the cost of the injection mold.

[0052] 5. The positioning device is processed by the injection molding method of the present invention, which replaces the use of tape and cable ties to fix the positioning device. The position size of the positioning device is guaranteed by the mold, and the size is accurate and consistent, which can better ensure the quality of the wiring harness product. At the same time, because the positioning device is integrally injection-molded on the wiring harness, the combination is more firm, the positioning device is not easy to fall off, the positioning effect is better, and in an environment with relatively harsh vibration conditions, the positioning device rarely has dimensional deviations or even detaches from the wiring harness, causing the wiring harness positioning function to fail, which can significantly extend the service life of the wiring harness. The assembly device adopts the injection molding processing method and can be set to different styles according to the different shapes of the wiring harness mounting end, which is more convenient for wiring harness installation and significantly improves the wiring harness installation efficiency. The positioning device adopts plastic parts, which are more convenient to injection mold. When assembled with the wiring harness mounting end, the elasticity of the plastic parts can better match the installation, significantly improving the installation efficiency of the positioning device. At the same time, due to the high corrosion resistance of the plastic parts, the service life of the wiring harness is greatly extended.

[0053] 6. The sealing device is processed by the injection molding method of the present invention. In the use environment of the wiring harness, the sealing device is used to seal the wet area and the dry area to prevent water in the wet area from entering the dry area, or entering the electrical circuit, damaging the electrical circuit in the dry area, causing the electrical function to fail, and in serious cases, causing safety accidents. The sealing device is integrally injection-molded using the injection molding process of the present invention. There is no need to pre-stretch the sealing device and then insert it into the wiring harness as in general wiring harness processing. This ensures that the position and size of the sealing device are accurate, and the sealing device can be more tightly combined with the protective layer. There is no need to use putty and sealant, saving material costs and installation time. Since it is a one-time shaping, the sealing device is not easily damaged, and is more tightly combined with the wiring harness protective layer. In addition, in an environment with relatively harsh vibration environments, the sealing device will not have dimensional deviations or even detach from the wiring harness, causing the wiring harness sealing function to fail, which can significantly extend the service life of the wiring harness. At the same time, the sealing device can also be arranged between the terminal and the conductor, and between the sheath and the protective layer, which can better seal the conductor, prevent the corrosion of the conductor by water in the external environment, and significantly extend the service life of the wiring harness. The sealing device adopts a rubber part, which has better fit with other parts. At the same time, the elasticity of the rubber part makes the sealing of the wiring harness better, which significantly improves the service life of the wiring harness.

[0054] 7. The wiring harness of the present invention uses a separate sheath or an integrally molded sheath, enabling faster installation with electrical devices, improving installation efficiency. It also allows for quick replacement of damaged wiring harnesses, improving wiring harness repair efficiency and reducing labor costs. The integrally molded sheath is faster to process and more tightly adheres to the terminal, protective layer, or insulation layer, significantly improving the sealing level of the wiring harness.

[0055] 8. The conductors can be solid, flat, or multi-stranded, with a variety of conductive portion cross-sections. Depending on the actual use environment of the wiring harness, the appropriate conductor structure can be adopted, saving wiring harness costs and improving wiring harness installation efficiency. Different conductor structures and conductive portion cross-sections can also accommodate terminals with different connection methods, making it easier for wiring harness designers to select terminals and conductors for use in the harness, further optimizing wiring harness costs and improving wiring harness product stability.

[0056] 9. In the wiring harness of the present invention, when there are more than two conductors belonging to the same circuit, the non-terminal side conductors are connected to form conductor connection points according to the circuit requirements by crimping or welding. This can reduce the amount of conductors used when designing the wiring harness, significantly reducing the cost of the wiring harness. At the same time, the conductor connection points are integrally injection-molded and sealed, ensuring that the conductor connection points will not be damaged during installation and use of the wiring harness. In harsh vibration environments, the conductor connection points that are integrally injection-molded and sealed will not be broken by vibration. In addition, the integral injection-molded and sealed seal can prevent water from corroding the conductor connection points, significantly extending the service life of the wiring harness.

[0057] 10. The present invention also provides a method for preparing an integral injection-molded wiring harness. By adopting different process flows according to different wiring harness structures, the production efficiency of the wiring harness can be significantly improved and the cost of the wiring harness can be reduced.

[0058] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of a wiring harness of the present invention with a single conductor, no sheath, and a positioning device and a sealing device.

[0060] Figure 2 This is a schematic diagram of a wiring harness comprising multiple conductors, a sheath, a protective layer, a positioning device, and a sealing device according to the present invention.

[0061] Figure 3-1 Schematic diagram of the cross section of a wire harness of a single conductor with a protective layer according to the present invention.

[0062] Figure 3-2 This is a schematic cross-sectional view of a wiring harness in which multiple conductors with protective layers are arranged in parallel.

[0063] Figure 3-3 This is a schematic cross-sectional view of a wiring harness in which multiple conductors with protective layers are arranged in a ring shape according to the present invention.

[0064] Figure 3-4 The figure is a schematic cross-sectional view of a wire harness of multiple conductors with an insulation layer and a protective layer according to the present invention.

[0065] Figure 4 Schematic diagram of a wiring harness with multiple conductors and conductor connection points according to the present invention.

[0066] Figure 5 Schematic diagram of the structure of the positioning device of the present invention.

[0067] Figure 6 Schematic diagram of the assembly device of the inverted tooth structure.

[0068] Figure 7 Schematic diagram of the assembly device of the clip-like structure.

[0069] Figure 8 Schematic diagram of the assembly device of the C-ring structure.

[0070] Figure 9 The figure is a schematic structural diagram of a wiring harness of the present invention having a sealing device that cooperates with a through hole on a partition plate.

[0071] Figure 10 It is a schematic structural diagram of the sealing device of the conductor, terminal and protective layer of the present invention.

[0072] Figure 11 Schematic diagram of the structure of the sealing device of the sheath of the present invention.

[0073] Figure 12 This is a schematic structural diagram of the one-piece injection-molded sheath of the present invention.

[0074] Among them, the figures are marked as: 1. terminal, 2. conductor, 3. insulation layer, 4. sealing device, 5. positioning device, 6. sheath, 7. protective layer, 8. wire harness protection device, 9. waterproof device, 10. second fixing device, 11. assembly device, 12. first fixing device, 13. waterproof cover, 14. slot. DETAILED DESCRIPTION

[0075] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention object, the specific implementation methods, structures, features and effects of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments:

[0076] Example 1

[0077] like Figure 1 、 Figure 3-1As shown, the wiring harness is composed of a single conductor, and the two ends of the conductor 2 are respectively connected to terminals 1. The terminal 1 is a copper terminal, and the copper terminal is made of a copper alloy with a copper content of 60%, which can ensure that the copper terminal has good conductivity and machinability. The surface of the terminal 1 is nickel-plated, and can also be plated with one of cadmium, zirconium, chromium, cobalt, manganese, aluminum, tin, titanium, zinc, copper, silver or gold. The plating can slow down the corrosion of the terminal and extend the service life of the terminal. One end of the terminal 1 is connected to the conductor 2, and when in use, the other end of the terminal 1 is used to connect the electrical circuit of the electrical device. In this embodiment, the conductor 2 is composed of a multi-core wire, and the cross-section of the multi-core wire is circular. In other embodiments, the conductor 2 can also be a solid conductor and a flat conductor. The cross-section of the conductive part of the conductor 2 can also be elliptical, polygonal, wavy or irregular. The wiring harness is provided with an injection-molded protective layer 7 that covers the outside of the conductor 2. The protective layer 7 is made of plastic or rubber. In this embodiment, the material of the protective layer 7 is PVC; and at least one injection-molded positioning device 5 for fixing the position of the wiring harness and / or a sealing device 4 for waterproofing.

[0078] The conductor 2 can be a purchased wire with an insulating layer 3, and a protective layer 7 is injection-molded outside the insulating layer 3; or the protective layer 7 can be directly injection-molded outside the conductor 2. Figure 3-1 As shown, the single conductor 2 is arranged in the middle and a protective layer 7 is injection-molded around the periphery.

[0079] After the conductor 2 is cut to a fixed length, its two ends are connected to the terminal 1 by crimping or welding. The semi-finished product is then placed in an injection mold, and the protective layer 7, the positioning device 5, and the sealing device 4 are injection molded according to the determined dimensions. The specific injection molding method is as follows:

[0080] (1) preparing semi-finished wire harnesses;

[0081] (2) placing the required raw materials into an injection molding device and drying them, and then placing the wire harness semi-finished product prepared in step (1) into an injection mold; or placing the wire harness semi-finished product prepared in step (1) into an injection mold, and then placing the required raw materials into an injection molding device and drying them.

[0082] (3) Start the injection molding equipment to heat and melt the raw materials and inject them into the injection mold for molding.

[0083] The positioning device 5 is made of PA66. In other embodiments, the positioning device 5 is a plastic part processed by injection molding. The positioning device 5 includes a first fixing device 12 connected to the wiring harness and an assembly device 11 connected to the mounting end of the wiring harness. The assembly device 11 is connected to the first fixing device 12. The first fixing device 12 is a tubular structure. The inner wall of the tubular structure cooperates with the outer surface of the protective layer 7 and wraps around the outer surface of the protective layer 7. The specific structure of the assembly device 11 can be a tooth structure that is inserted into the mounting hole, that is, the assembly device is a columnar structure, and the outer periphery of the columnar structure has a tooth structure that is inserted into the hole to be installed. In other embodiments, the assembly device can also be a clip-like structure that is connected to the plate, specifically with a groove, and barbs are set on the two side walls of the groove to engage with the plate. It can also be a circular ring or C-shaped ring structure assembled with a tubular or columnar structure.

[0084] It should be noted that the material of the sealing device 4 is FPDM. In other embodiments, the sealing device 4 is a rubber part processed by injection molding. Generally, when installing the wiring harness, it will pass through the holes on the partition board between the dry area and the wet area. In order to prevent water from the wet area from entering the dry area, Figure 9 As shown, the sealing device 4 in this example includes a second fixing device 10 connected to the wiring harness and a waterproof device 9, and the waterproof device 9 is connected to the second fixing device 10; the second fixing device 10 is a cylindrical structure, and the inner wall of the cylindrical structure cooperates with the outer surface of the protective layer 7 and is wrapped around the outer surface of the protective layer 7. The waterproof device 9 structure includes a waterproof sleeve 13 connected to the second fixing device 10 at one end, and a card slot 14 connected to the other end of the waterproof sleeve 13 to be assembled with the waterproof hole.

[0085] When the wiring harness is in a humid area, a sealing device is provided between the protective layer 7, the conductor 2 and the terminal 1 of the wiring harness to seal and wrap the protective layer 7, the conductor 2 and the terminal 1. Figure 10 As shown, the sealing device 4 is injection molded on the conductor 2, the connection between the terminal 1 and the conductor 2 and the outside of the protective layer. The corresponding parts of the conductor 2 and the terminal 1 are waterproof devices 9, and the corresponding parts of the protective layer 7 are second fixing devices 10.

[0086] Example 2

[0087] like Figure 2 、 Figure 3-2 、 Figure 3-3As shown, the wiring harness is composed of more than one conductor 2, and each of the conductors 2 is connected to a terminal 1 at both ends. The surface of the terminal 1 is galvanized, and can also be plated with one of nickel, cadmium, zirconium, chromium, cobalt, manganese, aluminum, tin, titanium, copper, silver or gold. The conductor 2 and the terminal 1 are the same as those in Example 1 and will not be described in detail. The difference from Example 1 is that the wiring harness is also provided with at least one sheath 6 that is plugged into the electrical device. After the conductor 2 is connected to the terminal 1, the terminal 1 is assembled in the sheath 6. Different terminals 1 correspond to different holes in the sheath 6 according to design requirements, so as to play the role of connecting different circuits, and at the same time protect the terminal 1 from damage. The sheath 6 is integrally injection molded onto at least the terminal 1.

[0088] After the conductors 2 are cut to length, their ends are crimped or welded to the terminals 1. The semi-finished product is then placed in an injection mold, and the protective layer 7, positioning device 5, and sealing device 4 are injection-molded according to the determined dimensions. The wiring harness protective layer 7 is injected first, followed by the wiring harness protective device 8, and finally the positioning device 5 or sealing device 4.

[0089] When the wiring harness is in a humid area, a sealing device 4 is provided between the protective layer 7, the conductor 2 and the terminal 1 of the wiring harness to seal and wrap the protective layer 7, the conductor 2 and the terminal 1. Figure 10 As shown, the sealing device 4 is injection molded on the conductor 2, the connection between the terminal 1 and the conductor and the outside of the protective layer 7, the corresponding parts of the conductor 2 and the terminal 1 are the waterproof device 9, and the corresponding part of the protective layer 7 is the second fixing device 10.

[0090] The specific injection molding method is as follows:

[0091] (1) preparing semi-finished wire harnesses;

[0092] (2) placing the required raw materials into an injection molding device and drying them, and then placing the wire harness semi-finished product prepared in step (1) into an injection mold; or placing the wire harness semi-finished product prepared in step (1) into an injection mold, and then placing the required raw materials into an injection molding device and drying them.

[0093] (3) Start the injection molding equipment to heat and melt the raw materials and inject them into the injection mold for molding.

[0094] Injection molding parameters include heating temperature, cooling temperature, injection pressure, injection time, etc., and are operated according to existing injection molding equipment, which is a conventional operation method. Requirements: The finished injection molded product must not have defects such as impurities, pits, flash, and air holes.

[0095] like Figure 3-2 、 3-3As shown, the multiple conductors 2 are arranged in the middle and a protective layer 7 is injected on the periphery. Firstly, the multiple conductors 2 are bound together to prevent the conductors 2 from spreading out when the wiring harness is installed. Secondly, the multiple conductors 2 are insulated and isolated to prevent the multiple conductors 2 from short-circuiting with each other and being damaged by external forces such as scraping after the wiring harness is installed. In this embodiment, the conductor 2 is a solid conductor or a flat conductor, and the cross-section of the conductive part of the conductor 2 is a special-shaped structure, which can also be elliptical or wavy. The protective layer 7 is made of PVC. The positioning device 5 and the sealing device 4 are the same as those in Example 1 and will not be described in detail.

[0096] Example 3

[0097] like Figure 4 As shown, the wiring harness is composed of more than one conductor 2, and the ends of a part of the conductors 2 are connected to the terminals 1, and the ends of the other part of the conductors 2 are connected to form conductor connection points according to the loop requirements by crimping or welding. The surface of the terminal 1 is silver-plated, and can also be plated with one of nickel, cadmium, zirconium, chromium, cobalt, manganese, aluminum, tin, titanium, zinc or gold. After the conductor 2 is connected to the terminal 1, the terminal 1 is assembled into a sheath 6 that is plugged into the electrical device, and different terminals 1 correspond to different holes in the sheath 6 according to design requirements. During preparation, the conductor connection point is sealed as a wiring harness protection device 8 as a whole; the wiring harness protection device 8 is a rubber part or plastic part processed by injection molding. As Figure 3-4 As shown, an insulating layer 3 is provided outside the conductor 2, and a protective layer 7 is injection-molded outside the insulating layer 3. The terminal 1 and the sheath 6 are the same as those in embodiment 1 and are not described in detail.

[0098] After the multiple conductors 2 are cut into fixed lengths, some of the conductors 2 are connected to the terminals 1 by crimping or welding according to the design requirements. When there are more than two conductors 2 in another part and they belong to the same loop, the non-terminal side conductors are connected to form conductor connection points according to the loop requirements by crimping or welding. The semi-finished product is then placed in an injection mold, and according to the determined size and the injection molding steps described in Example 2, the protective layer 7 is first injection-molded, then the wiring harness protection device 8 is injection-molded, and finally the positioning device 5 and / or the sealing device 4 are injection-molded. In this embodiment, the conductor 2 is composed of multiple strands of wire, and the cross-section of the conductive part of the conductor 2 is a polygonal structure. The material of the wiring harness protection device 8 is plastic. In other applications, the material of the wiring harness protection device 8 can also be rubber. The protective layer 7, positioning device 5, and sealing device 4 are the same as those in Example 2 and will not be elaborated on.

[0099] In the injection molding wire harness preparation method, when the wire harness semi-finished product is provided with a sheath 6, the terminal 1 of the connecting conductor 2 is inserted into the corresponding hole of the sheath 6 before injection molding; or the wire harness semi-finished product is injection molded first, and then the terminal 1 of the connecting conductor 2 is inserted into the corresponding hole of the sheath 6.

[0100] like Figure 11 As shown, when the sheath 6 is in a humid area, a sealing device 4 is provided to seal the holes of the sheath 6 to prevent water from entering the sheath 6. A waterproof device 9 is injection-molded in the connection gap between the sheath 6 and the conductor 2 to seal the sheath 6 for waterproofing. A second fixing device 10 is connected between the waterproof device 9 and the end of the sheath 6. The waterproof device 9 is injection-molded, and the second fixing device 10 is a sleeve structure that cooperates with the outer protective layer 7 of the conductor 2.

[0101] like Figure 12 As shown, the sheath 6 described in this example can also be integrally injection molded. The semi-finished wire harness is placed in an injection mold, and the sheath 6 is integrally injection molded onto at least the terminal 1. In other embodiments, the sheath 6 can also be integrally injection molded onto the terminal 1 and the conductor 2, or the sheath 6 can be integrally injection molded onto the terminal 1, the conductor 2 and the protective layer 7.

[0102] In order to demonstrate the effects of the wiring harness processed by the traditional method and the wiring harness integrally injection molded as described in Examples 1-3 of the present invention on the mechanical properties and electrical properties of the terminals and conductors of the wiring harness, the inventors of the present application conducted a series of experiments on the mechanical properties, electrical properties and lifespan of the wiring harness processed by the above two different methods.

[0103] The specific experimental process is as follows: simulate the actual use environment of the wiring harness, but increase the test conditions to a level far more stringent than that of ordinary environments. In this way, in a short period of time, the test results that can be achieved in a long time under the actual use environment can be obtained. The series of tests includes: 1) Initial pull-out force and voltage drop testing of Terminal 1 and Conductor 2 of both wiring harnesses to determine their initial mechanical and electrical properties; 2) A 1000-hour salt spray test, in which salt water is sprayed onto both wiring harnesses in a salt spray chamber, replacing the typical 10-year salt spray test in coastal environments; 3) A 200-hour high-low temperature test, in which both wiring harnesses are subjected to the highest and lowest operating temperatures for one hour each, with a temperature switching time of less than 5 seconds, for 100 cycles, replacing the typical 10-year high-low temperature test in an external hot-cold-hot environment; 4) A 120-hour vibration test, in which both wiring harnesses are mounted on a vibration test bench and subjected to vibration in three directions at an amplitude selected according to the operating environment, replacing the typical 10-year vibration test in an environmental environment; and 5) A 6000-hour aging test, in which both wiring harnesses are placed in an aging chamber to simulate an environment exceeding the rated operating conditions, replacing the typical 20-year aging test in an environmental environment. After each test, the voltage drop and pull-out force values ​​of Terminal 1 and Conductor 2 of both wiring harnesses are tested. The experimental results are shown in Table 1-1, Table 1-2 and Table 1-3.

[0104] Table 1-1: Effects of traditional wiring harnesses and one-piece injection molded wiring harnesses on the pull-out force and voltage drop between terminals and conductors (before and after 1000 hours of salt spray testing)

[0105]

[0106] Table 1-2: Effects of conventional wiring harnesses and one-piece injection-molded wiring harnesses on the pull-out force and voltage drop between terminals and conductors (200-hour high and low temperature test and 120-hour vibration test)

[0107]

[0108] Table 1-3: Effects of traditional wiring harnesses and one-piece injection molded wiring harnesses on the pull-out force and voltage drop between terminals and conductors (6000-hour aging test)

[0109]

[0110] From the results in Tables 1-1, 1-2, and 1-3 above, it can be seen that the initial pull-out force values ​​and voltage drop values ​​of terminal 1 and conductor 2 of the wiring harness processed by the traditional method and the wiring harness produced by integral injection molding are relatively close.

[0111] After undergoing a 1000-hour salt spray test, a 200-hour high and low temperature test, a 120-hour vibration test, and a 6000-hour aging test, the pull-out force values ​​of terminal 1 and conductor 2 of the one-piece injection-molded wiring harness after the test were much higher than those of the wiring harness processed by traditional methods, and were also relatively close to the initial pull-out force values.

[0112] However, for the wiring harness processed by traditional methods, the pull-out force values ​​of terminal 1 and conductor 2 after the experiment are significantly lower, and the mechanical properties are unstable, which may cause the terminal 1 and conductor 2 of the wiring harness to separate, thereby causing a short circuit in the wiring harness, which may lead to functional failure at the least and a fire accident at the worst.

[0113] For the one-piece injection-molded wiring harness, the voltage drop between terminal 1 and conductor 2 after the experiment is basically close to the initial voltage drop between terminal 1 and conductor 2 of the wiring harness processed by traditional methods.

[0114] For the wiring harness processed by traditional methods, the voltage drop value between terminal 1 and conductor 2 is significantly reduced after the experiment, the electrical performance is unstable, and the contact resistance between terminal 1 and conductor 2 of the wiring harness increases. When conducting electricity, the terminal 1 and conductor 2 of the wiring harness will cause them to heat up and turn red. In severe cases, they may burn due to excessive temperature, causing serious accidents.

[0115] Therefore, after the experiment, the mechanical and electrical properties of the terminal 1 and conductor 2 of the one-piece injection-molded wiring harness are far superior to those of the wiring harness processed by traditional methods, which can reduce the product defect rate and extend the service life of the wiring harness.

[0116] To demonstrate the positioning effectiveness of the fixtures for conventionally processed wire harnesses and the integrally injection-molded wire harnesses described in Examples 1-3 of the present invention under vibration conditions, 100 wires of each type were selected and subjected to vibration tests to evaluate the performance of the fixtures. The results are shown in the following table:

[0117] Table 2: Effects of vibration testing on fixture performance for conventional and integrally molded wiring harnesses (120-hour vibration test)

[0118]

[0119] As can be seen from the above table, the traditional wiring harness uses cable ties to fix the positioning device. The number of dimensional deviations of the positioning device 5 accounts for 52% of the total number of wiring harnesses, and the number of wire harnesses detached accounts for 11% of the total number of wiring harnesses, with a very high defective rate. The traditional wiring harness uses tape to fix the positioning device 5. The number of dimensional deviations of the positioning device 5 accounts for 69% of the total number of wiring harnesses, and the number of wire harnesses detached accounts for 24% of the total number of wiring harnesses, with a very high defective rate, which seriously affects the installation and function realization of the wiring harness, and in severe cases, the wiring harness function will fail.

[0120] In contrast, the three types of positioning devices 5 in the one-piece injection-molded wiring harness only experienced dimensional deviations of 0%, 1%, and 1% of the total number of wires, and the number of wires detached was 0%. Therefore, the one-piece injection-molded wiring harness provides a more secure bond between the positioning device 5 and the harness, making it less likely to fall off, resulting in better positioning. Furthermore, in environments with harsh vibrations, the positioning device 5 rarely experiences dimensional deviations or even detaches from the harness, causing the harness's positioning function to fail, significantly extending the harness's service life.

[0121] To demonstrate the protection level of the sealing device 4 against external dust and water erosion in wire harnesses processed by conventional methods and the integrally injection-molded wire harnesses described in Examples 1-3 of the present invention, 100 wire harnesses of each type were selected to test the performance of the sealing device 4 of the wire harnesses. The results are shown in the following table:

[0122] Table 3: Protection level pass rate of sealing devices for traditional wiring harnesses and one-piece injection molded wiring harnesses

[0123]

[0124] As can be seen from the table above, the three sealing devices 4 of traditional wiring harnesses have a protection level pass rate of only 89%, 92%, and 88% in the IP54 protection level test; and a protection level pass rate of only 68%, 75%, and 71% in the IP67 protection level test. The protection level pass rate is very low, and the sealing performance of the wiring harness cannot be guaranteed. It cannot prevent dust and water in the external environment from corroding the conductor 2, which may cause the wiring harness to fail.

[0125] The three sealing devices 4 of the one-piece injection molded wiring harness have a protection level pass rate of 100% in the IP54 protection level test; in the IP67 protection level test, the protection level pass rates are 99%, 100% and 100%, which are fully able to meet the sealing performance of the wiring harness, make the wiring harness more sealed, prevent the corrosion of dust and water in the external environment on the conductor, and significantly improve the service life of the wiring harness.

[0126] To compare the risk of conductor connection point breakage in conventionally processed wire harnesses and the integrally injection-molded wire harnesses described in Examples 1-3 of the present invention, 100 wire harnesses of each type were subjected to a 120-hour vibration test. The breakage rate of the conductor connection points was measured. The results are shown in the following table:

[0127] Table 4: Fracture ratio of conductor connection points for traditional wiring harnesses and one-piece injection molded wiring harnesses

[0128]

[0129] The table above shows that after a 120-hour vibration test, the breakage rate for the two traditional wiring harness conductor connection point wrapping methods was 26% for the conductor connection point wrapped with tape, and 18% for the conductor connection point wrapped with heat shrink tubing. This high breakage rate cannot guarantee the wiring harness's conductivity in harsh vibration environments, posing a significant risk of wiring harness failure.

[0130] The one-piece injection-molded wiring harness has an injection-wrapped conductor connection point with a breakage rate of 0%, which is fully capable of meeting the wiring harness's conductive performance in harsh vibration environments and significantly improving the wiring harness's service life.

[0131] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. An injection molded wiring harness, characterized in that: The wiring harness includes a terminal and at least one conductor, one end of the terminal is connected to the electrical circuit of the electrical device, and the other end of the terminal is connected to the conductor. The wiring harness is provided with an injection-molded protective layer covering the outside of the conductor, and at least one injection-molded positioning device for fixing the position of the wiring harness and / or a sealing device for waterproofing; The wiring harness includes more than two conductors, and a portion of the conductors extending in two different directions are connected to form a conductor connection point for current diversion. The conductor connection point is located between the positioning device and the sealing device. The conductor connection point is sealed as a whole by the wiring harness protection device, and the protective layer covers the wiring harness protection device and the conductors.

2. The injection molded wiring harness according to claim 1, characterized in that: An insulating layer is further provided on the outside of the conductor, and a protective layer is injection-molded outside the insulating layer.

3. The injection molded wiring harness according to claim 1, characterized in that: The positioning device includes a first fixing device connected to the wire harness and an assembly device connected to the mounting end of the wire harness, wherein the assembly device is connected to the first fixing device.

4. The injection molded wiring harness according to claim 3, characterized in that: The first fixing device is a cylindrical structure, and the inner wall of the cylindrical structure cooperates with the outer surface of the protective layer and wraps around the outer surface of the protective layer.

5. The injection molded wiring harness according to claim 3, characterized in that: The assembly device is a columnar structure, and the outer periphery of the columnar structure has a reverse tooth structure.

6. The injection molded wiring harness according to claim 3, characterized in that: The assembly device has a clip-like structure.

7. The injection molded wiring harness according to claim 6, characterized in that The clip-shaped structure has a groove, and barbs are arranged on both side walls of the groove.

8. The injection molded wiring harness according to claim 3, characterized in that: The assembly device has a circular ring structure or a C-shaped ring structure.

9. The injection molded wiring harness according to claim 3, characterized in that: The positioning device is a plastic part processed by injection molding.

10. The injection molded wiring harness according to claim 1, characterized in that: The sealing device includes a second fixing device connected to the wiring harness and a waterproof device, and one end of the waterproof device is connected to the second fixing device.

11. The injection molded wiring harness according to claim 10, characterized in that: The second fixing device is a cylindrical structure, and the inner wall of the cylindrical structure cooperates with the outer surface of the protective layer and wraps around the outer surface of the protective layer.

12. The injection molded wiring harness according to claim 10, characterized in that: The sealing device is a rubber part processed by injection molding.

13. The injection molded wiring harness according to claim 1, characterized in that: The wiring harness is further provided with at least one sheath for plugging into the electrical device, and the terminals are assembled in corresponding holes of the sheath.

14. The injection molded wiring harness according to claim 13, characterized in that: The sheath is integrally injection-molded onto at least the terminal.

15. The injection molded wiring harness according to claim 1, characterized in that: The conductor is a solid conductor, a flat conductor, or a conductor with multiple strands of wire.

16. The injection molded wiring harness according to claim 1, characterized in that: The terminal is connected to a conductor such as a solid conductor, a flat conductor, or a multi-strand conductor by crimping or welding.

17. The injection molded wiring harness according to claim 1, characterized in that: The cross section of the conductive portion of the conductor is circular, elliptical, polygonal, wavy or irregular.

18. A method for preparing the wiring harness according to any one of claims 1 to 17, characterized in that: (1) preparing semi-finished wire harnesses; (2) placing the required raw materials into the injection molding equipment and drying them, and then placing the wire harness semi-finished product prepared in step (1) into the injection mold; Alternatively, the semi-finished wire harness prepared in step (1) is placed into an injection mold, and then the required raw materials are placed into the injection molding equipment and dried; (3) Start the injection molding equipment to heat and melt the raw materials and inject them into the injection mold for molding; The method further includes the following steps: preparing a semi-finished wire harness having more than two conductors, and connecting a portion of the conductors extending in two different directions to form a conductor connection point for current diversion by crimping or welding; and firstly injecting a wire harness protection device to seal the conductor connection point as a whole according to steps (2) to (3), then injecting a protective layer, and finally injecting a positioning device or a sealing device, wherein the conductor connection point is located between the positioning device and the sealing device.

19. The method according to claim 18, wherein: When the semi-finished wire harness is provided with a sheath, the terminals of the connecting conductors are inserted into the corresponding holes of the sheath before injection molding; or the semi-finished wire harness is injection molded first, and then the terminals of the connecting conductors are inserted into the corresponding holes of the sheath.

20. The method of claim 19, wherein: The semi-finished wire harness product is placed into an injection mold, and the sheath is integrally injection-molded onto at least the terminal.

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