An engine fuel injector inlet fitting assembly method

Abstract

The application discloses an engine fuel injector inlet joint assembling method, and belongs to the technical field of engine assembling, which solves the problem of easy oil leakage of the existing assembling method. The assembling method comprises the following steps: S1, pre-tightening the fuel injector to the cylinder head, and making the inlet joint face the high-pressure oil pipe side; S2, installing the high-pressure common rail pipe to the cylinder head and tightly fixing it in place; S3, aligning the two ends of the high-pressure oil pipe with the high-pressure common rail pipe and the inlet joint respectively, and tightly fixing the corresponding nuts at the two ends of the high-pressure oil pipe, at this time, the inlet joint is self-adjusted to the angle; S4, tightly screwing the fuel injector to meet the torque requirement, making the fuel injector compress the inlet joint, and completing the positioning of the inlet joint; S5, loosening the corresponding nuts at the two ends of the high-pressure oil pipe, and taking down the high-pressure oil pipe; S6, installing the cylinder head cover to the cylinder head, and tightly fixing it in place. The assembling method can reduce the phenomenon of engine oil and diesel oil leakage, and effectively improve the assembling quality and efficiency.

Description

Technical Field

[0001] This invention relates to the field of engine assembly technology, and more specifically, to a method for assembling an engine injector inlet connector. Background Technology

[0002] During engine assembly, the fuel injector inlet connector is usually installed inside the cylinder head cover. The existing assembly method is as follows: first, install the fuel injector into the cylinder head and pre-tighten it; then adjust the fuel injector inlet angle (relying on experience to visually check if it is adjusted in place); then tighten the corresponding fastening bolts of the fuel injector to fix the fuel injector; next, install the cylinder head cover and tighten its corresponding fastening bolts; finally, install the high-pressure fuel line.

[0003] The engine assembled using the above method was found to leak diesel fuel at the injector inlet joint and oil at the high-pressure fuel line seal during testing. Repeated disassembly and reassembly of the injector inlet joint failed to resolve the problem, wasting valuable test bench resources and severely impacting project development progress. Disassembly and analysis revealed that the primary cause was the lack of circumferential positioning design in the injector inlet joint. Adjustments were made entirely by visual inspection and experience of the assembly personnel. After deeming the adjustment satisfactory, the injector was tightened, followed by tightening the cylinder head cover and the high-pressure fuel line clamping cap. Because the injector joint was eccentrically positioned (the inlet joint was offset from the fuel line hole in the cylinder head cover), tightening the high-pressure fuel line clamping cap damaged the threads, resulting in a poor seal and diesel fuel leakage into the oil pan. Simultaneously, the misalignment of the high-pressure fuel line clamping cap (one-sided sealing) caused oil to splash out from the gaps in the cylinder head cover.

[0004] Therefore, there is an urgent need to develop and design a new method for assembling engine injector inlet connectors to solve the above-mentioned technical problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art. The purpose of the present invention is to provide an assembly method for an engine injector inlet connector, which can reduce the leakage of engine oil and diesel fuel, and effectively improve assembly quality and efficiency.

[0006] To achieve the above objectives, the present invention provides a method for assembling an engine injector inlet connector, the method comprising the following steps: S1. Pre-tighten the injector to the cylinder head and make the fuel inlet connector face the high-pressure fuel line. S2. Install the high-pressure common rail into the cylinder head and tighten it in place; S3. Align both ends of the high-pressure oil pipe with the high-pressure common rail pipe and the oil inlet connector respectively, and tighten the corresponding nuts at both ends of the high-pressure oil pipe. At this time, the oil inlet connector will adjust its angle automatically. S4. Tighten the injector to meet the torque requirements to press the injector against the inlet connector and complete the positioning of the inlet connector. S5. Loosen the nuts at both ends of the high-pressure oil pipe and remove the high-pressure oil pipe; S6. Install the cylinder head cover onto the cylinder head and tighten it into place. S7. Align both ends of the high-pressure oil pipe with the high-pressure common rail pipe and the oil inlet connector, and tighten the corresponding nuts at both ends of the high-pressure oil pipe.

[0007] As a further improvement, before step S1, step S0 is also included. The specific operation of step S0 is: to determine whether the engine to be installed is a new engine or an old engine that has already been installed. If the engine to be installed is a new engine, proceed to step S1; If the engine to be installed is an old one, first remove the high-pressure fuel line and cylinder head cover, then loosen the fuel injector, and finally proceed to step S3.

[0008] Furthermore, step S6 includes the following specific steps: S6.1. Pre-tighten the cylinder head cover onto the cylinder head; S6.2 Observe the position of the fuel inlet connector and determine whether the fuel inlet connector is centered. If the fuel inlet connector is not centered, remove the cylinder head cover and high-pressure fuel line, then loosen the fuel injector, and finally proceed to step S3. If the fuel inlet connector is centered, proceed to step S6.3. S6.3 Tighten the cylinder head cover to secure it in place.

[0009] Furthermore, in step S4, the torque for tightening the injector is 33 N·m to 37 N·m.

[0010] Beneficial effects Compared with the prior art, the advantages of this invention are as follows: The assembly method of this invention adds adjustment to the fuel injector inlet connector of the existing assembly process. It cleverly uses the pre-positioned common rail and high-pressure fuel line (formed tube) as a reference to self-adjust and precisely position the angle of the fuel injector inlet connector. This solves the problem of fuel injector connector misalignment (fuel inlet connector deviating from the cylinder head cover fuel line hole), which damages the threads when tightening the high-pressure fuel line clamping nut, resulting in poor sealing and diesel leakage into the fuel pan. At the same time, it solves the problem of oil splashing out of the cylinder head cover due to the high-pressure fuel line clamping nut being misaligned (single-sided sealing of the sealing ring), reducing oil and diesel leakage, effectively improving assembly quality and efficiency; and it eliminates the need for auxiliary positioning fixtures, which not only reduces the difficulty of operation but also reduces costs. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the assembled structure of the present invention; Figure 2 This is a partial structural diagram of the assembled invention.

[0012] Among them: 1-injector, 2-cylinder head, 3-inlet connector, 4-high pressure fuel line, 5-high pressure common rail, 6-nut. Detailed Implementation

[0013] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0014] See Figure 1-2 The present invention provides a method for assembling an engine injector inlet connector, the method comprising the following steps: S1. Pre-tighten the injector 1 onto the cylinder head 2. The fuel inlet connector 3 is a component that fits onto the injector 1. After the injector 1 is pre-installed, rotate the fuel inlet connector 3 so that the fuel inlet connector 3 faces the high-pressure fuel pipe 4. S2. Install the high-pressure common rail pipe 5 into the cylinder head 2 and tighten it in place. Install and fix the common rail pipe 5 in advance as the installation reference for the high-pressure oil pipe 4. S3. Align both ends of the high-pressure oil pipe 4 with the high-pressure common rail pipe 5 and the oil inlet connector 3 respectively, and tighten the corresponding nuts 6 at both ends of the high-pressure oil pipe 4. Since the high-pressure oil pipe 4 is a rigid formed pipe and the position of each oil outlet pipe of the high-pressure common rail pipe 5 is fixed, the oil inlet connector 3 will adjust its angle by itself after the high-pressure oil pipe 4 is installed. S4. Tighten the injector 1 to meet the torque requirements so that the injector 1 presses against the inlet connector 3, thus completing the positioning of the inlet connector 3. S5. Loosen the nuts 6 at both ends of the high-pressure oil pipe 4 and remove the high-pressure oil pipe 4 in order to install the cylinder head cover; S6. Install the cylinder head cover onto the cylinder head 2 and tighten it in place. The top surface of the cylinder head 2 has a mounting flange. Place the cylinder head cover onto the mounting flange and tighten it with screws to complete the installation. S7. Align both ends of the high-pressure oil pipe 4 with the high-pressure common rail pipe 5 and the oil inlet connector 3 respectively, and tighten the corresponding nuts 6 at both ends of the high-pressure oil pipe 4 to complete the installation of the high-pressure common rail system.

[0015] The assembly method of this invention adds adjustment to the fuel injector inlet connector of the existing assembly process. It cleverly uses the pre-positioned common rail and high-pressure fuel line (formed tube) as a reference to self-adjust and precisely position the angle of the fuel injector inlet connector. This solves the problem of fuel injector connector misalignment (fuel inlet connector deviating from the cylinder head cover fuel line hole), which damages the threads when tightening the high-pressure fuel line clamping nut, resulting in poor sealing and diesel leakage into the fuel pan. At the same time, it solves the problem of oil splashing out of the cylinder head cover due to the high-pressure fuel line clamping nut being misaligned (single-sided sealing of the sealing ring), reducing oil and diesel leakage, effectively improving assembly quality and efficiency; and it eliminates the need for auxiliary positioning fixtures, which not only reduces the difficulty of operation but also reduces costs.

[0016] Preferably, before step S1, there is also step S0, the specific operation of which is: to determine whether the engine to be installed is a new engine or an old engine that has already been installed; If the engine to be installed is a new engine, proceed to step S1; If the engine to be installed is an old one, first remove the high-pressure oil pipe 4 and cylinder head cover, then loosen the injector 1, and finally proceed to step S3.

[0017] In this embodiment, by understanding the type of the assembly object in advance, the assembly of a new engine or the readjustment and assembly of an old engine can be completed quickly.

[0018] Preferably, step S6 includes the following specific steps: S6.1. Pre-tighten the cylinder head cover onto the cylinder head 2; S6.2 Observe the position of the fuel inlet connector 3 and determine whether the fuel inlet connector 3 is centered. If the fuel inlet connector 3 is not centered, remove the cylinder head cover and high pressure oil pipe 4, then loosen the injector 1, and finally proceed to step S3. If the fuel inlet connector 3 is centered, proceed to step S6.3. S6.3 Tighten the cylinder head cover to secure it in place.

[0019] In this embodiment, before assembling the cylinder head cover, the position of the oil inlet connector 3 is observed again to ensure that the oil inlet connector 3 is accurately assembled before tightening the cylinder head cover, thereby further improving the assembly quality.

[0020] In step S4, the torque for tightening the injector (1) is 33 N·m to 37 N·m, which can better fix the injector 1 and the inlet connector 3.

[0021] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for assembling an engine injector inlet connector, characterized in that, The assembly method includes the following steps: S1. Pre-tighten the injector (1) onto the cylinder head (2) and make the oil inlet connector (3) face the high pressure oil pipe (4); S2. Install the high-pressure common rail pipe (5) into the cylinder head (2) and tighten it in place; S3. Align the two ends of the high-pressure oil pipe (4) with the high-pressure common rail pipe (5) and the oil inlet connector (3) respectively, and tighten the corresponding nuts (6) at both ends of the high-pressure oil pipe (4). At this time, the oil inlet connector (3) will adjust its angle by itself. S4. Tighten the injector (1) to meet the torque requirements so that the injector (1) presses against the oil inlet connector (3) to complete the positioning of the oil inlet connector (3); S5. Loosen the nuts (6) at both ends of the high-pressure oil pipe (4) and remove the high-pressure oil pipe (4); S6. Install the cylinder head cover onto the cylinder head (2) and tighten it in place; S7. Align both ends of the high-pressure oil pipe (4) with the high-pressure common rail pipe (5) and the oil inlet connector (3) respectively, and tighten the corresponding nuts (6) at both ends of the high-pressure oil pipe (4).

2. The method for assembling an engine injector inlet connector according to claim 1, characterized in that, Before step S1, there is also step S0, and the specific operation of step S0 is: to determine whether the engine to be installed is a new engine or an old engine that has already been installed. If the engine to be installed is a new engine, proceed to step S1; If the engine to be installed is an old one, first remove the high-pressure oil pipe (4) and cylinder head cover, then loosen the injector (1), and finally proceed to step S3.

3. The method for assembling an engine injector inlet connector according to claim 1, characterized in that, Step S6 includes the following specific steps: S6.

1. Pre-tighten the cylinder head cover onto the cylinder head (2); S6.2 Observe the position of the oil inlet connector (3) and determine whether the oil inlet connector (3) is centered. If the oil inlet connector (3) is not centered, remove the cylinder head cover and high pressure oil pipe (4), then loosen the injector (1), and finally proceed to step S3. If the oil inlet connector (3) is centered, proceed to step S6.

3. S6.3 Tighten the cylinder head cover to secure it in place.

4. A method for assembling an engine injector inlet connector according to any one of claims 1-3, characterized in that, In step S4, the torque for tightening the injector (1) is 33 N·m to 37 N·m.

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