A fuel injector cable assembly front mounted on a diesel engine cylinder head

Abstract

The present invention provides an injector cable assembly that is front-mounted on a diesel engine cylinder head, which belongs to the field of engines and includes an electric connector assembly, a wiring harness, and a wiring terminal; the cylinder head is provided with a mounting hole, the electric connector is connected to the cylinder head, the middle of one end of the electric connector assembly is connected to the wiring terminal through a wiring harness, the wiring harness passes through the mounting hole, and the wiring terminal is connected to the injector mounted on the cylinder head. The present invention is used to solve the installation problem of the injector drive wiring harness on the cylinder head and the problem of electrical discontinuity of the system shielding layer and incomplete electrostatic shielding layer at the injector.

Description

Technical Field

[0001] The invention belongs to the field of diesel engines, and in particular relates to an injector cable assembly which is front-mounted on a cylinder head of a diesel engine. Background Art

[0002] With the widespread application of high-pressure common rail diesel engines in special vehicles and the increasing number of electronic equipment on the whole vehicle, the electromagnetic environment on the whole vehicle is becoming more and more complex, and higher requirements are placed on the electromagnetic capacitance of the diesel engine electronic control system. In order to meet the electromagnetic compatibility requirements and prevent external interference injection or external radiation emission, it is required that the metal shells or shielding layers of the various components of the diesel engine electronic control system and their connected components should have good electrical continuity to achieve the integrity of the electrostatic shielding.

[0003] The high-pressure common rail diesel engine injector is an important component installed in the diesel engine cylinder. It is driven by the diesel engine electronic control system through high-frequency pulse current to drive the high-speed solenoid valve inside the injector to realize the injection action. The frequent changes of the current in the injector drive wire will radiate electromagnetic interference outward, which will have a negative impact on the electromagnetic environment of the whole vehicle. At the same time, the electromagnetic interference radiated outward by other electronic equipment on the whole vehicle will also enter the electronic control system through the injector drive wire, which will have an adverse effect on the operation of the injector and the entire diesel engine electronic control system. At present, the wiring method used for the injector high-speed solenoid valve is: directly lead the wire from its terminal or connect it to the diesel engine electronic control system through a plastic electrical connector. This will cause the shielding layer of the entire diesel engine electronic control system to have electrical discontinuity and incomplete electrostatic shielding layer at the injector, resulting in the diesel engine electronic control system failing to meet the electromagnetic compatibility requirements of the special vehicle. At the same time, the environment in the diesel engine cylinder is relatively harsh, and the design of the injector cable assembly needs to fully consider the influence of comprehensive environmental stress factors such as oil and gas, high temperature, vibration and shock in the cylinder. Summary of the invention

[0004] In view of this, the present invention aims to propose an injector cable assembly that is front-mounted on a diesel engine cylinder head to solve the problem of installing the injector drive harness on the cylinder head and the problems of electrical discontinuity of the system shielding layer and incomplete electrostatic shielding layer at the injector.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A fuel injector cable assembly front-mounted on a diesel engine cylinder head is characterized in that it comprises an electrical connector assembly, a wiring harness and a wiring terminal; the cylinder head is provided with a mounting hole, the electrical connector is connected to the cylinder head, the middle part of one end of the electrical connector assembly is connected to the wiring terminal through a wiring harness, the wiring harness passes through the mounting hole, and the wiring terminal is connected to the fuel injector mounted on the cylinder head.

[0007] Furthermore, a mounting plate is provided in the middle of the electrical connector assembly, and the mounting plate is a square flange, which is installed and connected to the cylinder head assembly through bolts to achieve the connection between the electrical connection assembly and the cylinder head; a shell is provided at one end of the electrical connector assembly, and the shell is a hollow structure, and the connection point between the wiring harness and the electrical connector assembly is arranged in the shell; the shell is used to be inserted into the mounting hole.

[0008] Furthermore, a conductive rubber pad is provided between the mounting plate and the cylinder head, and the conductive rubber pad is used to establish electrical continuity and improve sealing between the electrical connector assembly and the cylinder head.

[0009] Furthermore, a groove is provided on the circumferential outer surface of the shell, and a fluorosilicone rubber sealing ring is installed in the groove. The fluorosilicone rubber sealing ring is used to improve the sealing performance of the assembly between the shell and the mounting hole, and the length of the shell is smaller than the depth of the mounting hole.

[0010] Furthermore, a contact is provided at one end of the electrical connector assembly, and the contact is used for welding to the wiring harness. A heat shrink tube is sleeved at the welding point between the contact and the wiring harness, and silicone is poured into the inner cavity of the shell to fix and seal the welding point wrapped with the heat shrink tube. Epoxy resin glue is set at the port of the shell to seal and fix the wiring harness.

[0011] Furthermore, a mold is provided at the port of the shell, and epoxy resin glue is poured into the mold for shaping, and the length of the epoxy resin glue after molding is 13-20 mm.

[0012] Furthermore, a protective layer is sleeved on the outside of the wiring harness, and the protective layer fits tightly against the wiring harness. The protective layer is made of TPE material, and an identification sleeve is also sleeved on the outside of the protective layer.

[0013] Furthermore, the wiring terminal is provided with a self-locking plug spring, which is adapted to the plug-in wiring terminal of the injector, and the outside of the wiring terminal is sheathed with a nylon flame-retardant flexible sheath or a nylon right-angle sheath for flame retardancy and insulation protection of the wiring terminal.

[0014] Compared with the prior art, the fuel injector cable assembly pre-installed on the diesel engine cylinder head of the present invention has the following advantages:

[0015] (1) The present invention provides an injector cable assembly that is front-mounted on a diesel engine cylinder head, which is easy to disassemble and use and has strong versatility. According to the form of the outlet terminal of the high-speed solenoid valve of different injectors (such as screw terminals, plastic sockets, etc.), the terminal with a self-locking plug spring is replaced with a corresponding terminal (such as a nut-type terminal, a plug, etc.), so that it can be assembled with other types of injectors.

[0016] (2) The fuel injector cable assembly of the present invention, which is pre-installed on the diesel engine cylinder head, not only meets the use requirements of the special environment inside the cylinder head (high temperature, oil and gas, etc.), but also realizes the electrical continuity of the overall shielding layer of the diesel engine electronic control system and the integrity of the electrostatic shielding under the premise of the sealing requirements of the cylinder head.

[0017] (3) The fuel injector cable assembly of the present invention, which is front-mounted on the cylinder head of a diesel engine, has a simple and practical structure, a low processing difficulty, and a low cost, and is easy to be widely promoted.

[0018] (4) The fuel injector cable assembly of the present invention, which is front-mounted on the cylinder head of a diesel engine, adopts a double-glue sealing and fixing method, which not only improves the sealing and insulation performance at the welding point, but also enhances the vibration, impact and pulling resistance of the welding point and the wiring harness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0020] Figure 1 This is a cross-sectional view of an injector cable assembly front-mounted on a diesel engine cylinder head according to an embodiment of the present invention;

[0021] Figure 2 Schematic diagram of a mounting plate according to an embodiment of the present invention.

[0022] Description of reference numerals:

[0023] 1. Electrical connector assembly; 11. Mounting plate; 12. Housing; 13. Conductive silicone; 14. Groove; 15. Silicone; 16. Epoxy resin glue; 2. Wiring harness; 3. Terminal block; 4. Identification sleeve. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0027] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0028] A fuel injector cable assembly mounted on a diesel engine cylinder head, such as Figure 1 As shown, it includes an electric connector assembly 1, a wiring harness 2 and a terminal block 3; the cylinder head is provided with a mounting hole, and the mounting plate 11 is reserved for the cylinder head for the electric connector assembly 1; the electric connector is connected to the cylinder head, and the middle part of one end of the electric connector assembly 1 is connected to the terminal block 3 through the wiring harness 2, the wiring harness 2 passes through the mounting hole, and the terminal block 3 is connected to the injector installed on the cylinder head.

[0029] Preferably, a mounting plate 11 is provided in the middle of the electrical connector assembly 1, and the mounting plate 11 is a square flange. Figure 2 As shown, the mounting plate is connected to the cylinder head assembly by bolts to realize the connection between the electrical connection assembly and the cylinder head; a circular hole is provided at each of the four corners of the mounting plate, and the specification of the circular hole is M3×4. Preferably, a conductive rubber pad is also provided between the mounting plate 11 and the cylinder head, and the conductive rubber pad is used to establish electrical continuity and improve sealing between the electrical connector assembly 1 and the cylinder head. The contour of the conductive rubber pad matches the contour of the mounting plate, and a circular hole of M3×4 is also provided.

[0030] Preferably, a shell 12 is provided at one end of the electrical connector assembly 1, and the shell 12 is a hollow structure. The connection point between the wiring harness 2 and the electrical connector assembly 1 is arranged inside the shell 12; the shell 12 is used to be inserted into the mounting hole.

[0031] Preferably, a groove 14 is provided on the circumferential outer surface of the shell 12, and a fluorosilicone rubber sealing ring is installed in the groove 14. The fluorosilicone rubber sealing ring is used to improve the sealing performance of the assembly between the shell 12 and the mounting hole to prevent the leakage of oil and gas inside the cylinder body; and the length of the shell 12 is less than the depth of the mounting hole.

[0032] Preferably, a double-glue fixing and sealing method is adopted inside the shell 12. A contact is provided at one end of the electrical connector assembly 1, and the contact is used to be welded to the wiring harness 2. A heat shrink tube is sleeved at the welding point between the contact and the wiring harness 2. Silicone gel 15 is poured into the inner cavity of the shell 12, and the silicone gel 15 is 704 silicone gel 15; it is used to fix and seal the welding point wrapped with the heat shrink tube. Epoxy resin glue 16 is set at the port of the shell 12 to seal and fix the wiring harness 2.

[0033] Preferably, the epoxy resin glue 16 is DG-3S epoxy resin glue 16 .

[0034] Preferably, a mold is provided at the port of the shell 12, and the mold is shaped by pouring epoxy resin glue 16 into the mold. The end surface of the epoxy resin glue 16 after molding is 15 mm longer than the end surface of the shell 12 where the epoxy resin glue 16 is provided.

[0035] Preferably, the outside of the wiring harness 2 is sleeved with a protective layer. The wiring harness 2 is required to use a high-temperature and oil-resistant flexible wire that is extruded once according to the internal environment of the diesel engine cylinder (temperature, oil and gas characteristics, and space size) and the working current of the injector solenoid valve. The length is 12 cm, and its internal wire is a 2-core AF-200-1.0mm2 high-temperature resistant wire (operating temperature range -50°C ~ 125°C). The external protective layer of the wiring harness 2 is an oil-resistant and high-temperature resistant TPE material, and the internal wire core is required to fit tightly with the external protective layer. The protective layer is also sleeved with an identification sleeve 4. The identification sleeve 4 adopts a white or yellow wear-resistant and oil-resistant heat shrink tube, and the identification content thereon is processed by laser engraving technology to ensure that the identification is not corroded and damaged in the oil and gas environment inside the cylinder head.

[0036] Preferably, the terminal block 3 with a self-locking plug spring is a locking spring terminal made of tin-plated copper (the material thickness is not less than 0.4 mm, and the jack is adapted to the injector plug), and a push-lock hook is designed inside, and the rear end wire groove is adapted to the wire with a cross-sectional area of ​​1.0 mm2; this end of the electrical connector assembly 1 can select different terminal blocks 3 or connectors for use with the injector according to the form of the outlet terminal of the injector high-speed solenoid valve, and is adapted to the plug-in terminal block 3 of the injector, and the terminal block 3 is externally sleeved with a nylon flame-retardant flexible sheath or a nylon right-angle sheath for flame retardant and insulation protection of the terminal block 3.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuel injector cable assembly front mounted on a diesel engine cylinder head, characterized in that: It includes an electric connector assembly, a wiring harness and a terminal block; the cylinder head is provided with a mounting hole, the electric connector is connected to the cylinder head, the middle part of one end of the electric connector assembly is connected to the terminal block through a wiring harness, the wiring harness passes through the mounting hole, and the terminal block is connected to the injector mounted on the cylinder head; a mounting plate is provided in the middle of the electric connector assembly, the mounting plate is a square flange, and the mounting plate is connected to the cylinder head assembly through bolts to achieve the connection between the electric connection assembly and the cylinder head; a shell is provided at one end of the electric connector assembly, the shell is a hollow structure, and the connection point between the wiring harness and the electric connector assembly is arranged in the shell; the shell is used to be inserted into the mounting hole; The wiring terminal is provided with a self-locking plug spring, which is adapted to the plug-in wiring terminal of the injector, and the wiring terminal is externally sleeved with a nylon flame-retardant flexible sheath or a nylon right-angle sheath for flame retardancy and insulation protection of the wiring terminal; A conductive rubber pad is also provided between the mounting plate and the cylinder head, and the conductive rubber pad is used to establish electrical continuity between the electrical connector assembly and the cylinder head and improve the sealing performance; A groove is provided on the circumferential outer surface of the shell, and a fluorosilicone rubber sealing ring is installed in the groove. The fluorosilicone rubber sealing ring is used to improve the sealing performance of the assembly between the shell and the mounting hole, and the length of the shell is less than the depth of the mounting hole; A contact is provided at one end of the electrical connector assembly, and the contact is used for welding to the wiring harness. A heat shrink tube is sleeved at the welding point between the contact and the wiring harness. Silicone is poured into the inner cavity of the shell to fix and seal the welding point wrapped with the heat shrink tube. Epoxy resin glue is set at the port of the shell to seal and fix the wiring harness.

2. The fuel injector cable assembly front-mounted on a diesel engine cylinder head according to claim 1, characterized in that: A mold is provided at the port of the shell, and epoxy resin glue is poured into the mold for shaping. The length of the epoxy resin glue after molding is 13-16 mm.

3. The fuel injector cable assembly front-mounted on a diesel engine cylinder head according to claim 1, characterized in that: The outside of the wiring harness is sleeved with a protective layer, which fits tightly to the wiring harness. The protective layer is made of TPE material, and an identification sleeve is also sleeved outside the protective layer.

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