High pressure common rail oil sprayer without static leakage

Abstract

Provided is a high pressure common rail oil sprayer without static leakage. An integral structure of an electromagnetic spraying control valve is changed into a split structure, the length of an upper guide section of an armature rod is reduced, the weight of the armature rod is substantially reduced, impact force generated by the armature rod in the high-speed opening and closing process is reduced, impact force of a control ball assembly to a conical surface oil hole of the top end of a valve sleeve is reduced, the speed of abrasion to a seal pair of the control ball assembly and the conical surface oil hole of the top end of the valve sleeve, and the service life of the common rail oil sprayer is prolonged. The lower end face of a valve rod is provided with a precise matching hole used for installing a guide post at the upper end of a valve needle, the sealing performance of a variable pressure cavity is guaranteed, the opening and closing response speed and use stability of the valve needle are increased, and if a damping groove is additionally formed in the guide post at the upper end of the valve needle, the opening and closing response sensitivity of the valve needle can be further improved. The service life of the common rail oil sprayer can be prolonged, the opening and closing response speed is increased, the product structure can also be simplified, manufacturability is optimized, and production cost is reduced.

Description

Technical field: [0001] The invention relates to a diesel engine high-pressure common rail technology, in particular to a high-pressure common rail fuel injector. Background technique: [0002] With the progress of society, the requirements for energy saving and emission reduction of diesel engines are getting higher and higher; this puts forward new requirements for the fuel supply system of diesel engines, requiring them to provide higher pressure fuel with more accurate timing and injection volume; With the development and improvement of high-pressure common rail technology for diesel engines, the common rail system has become the only fuel supply system that can meet the above three requirements at the same time. [0003] The common rail injector is a key component of the common rail system. Its working principle is to control the opening and closing of the high-speed solenoid valve through the electronic control unit (ECU), and inject high-pressure fuel into the combust...

AI Technical Summary

Problems solved by technology

[0006] The applicant conducted structural analysis and performance tests on the above-mentioned common rail injector and found that, in this common rail injector, the structure of the electromagnetic injection control valve 1 is complicated, the structural design of the control valve seat 17 is unreasonable, and the processing The workmanship is poor, especially the oil drain hole is difficult to process, the structure of the armature rod 14 is unreasonable, and the solid volume of the upper part of the armature rod 14 is too heavy. , the impact force of its motion inertia is extremely large, so that the service life of the sealing pair between the bottom sealing sphere of the armature rod 14 and the oil outlet cone hole at the top of the valve sleeve 3 cannot be guaranteed, which is the main reason for the short service life of the common rail injector

[0007] In the existing common rail injector, the main reason for the slow response speed of opening and closing is caused by the hydraulic coupling 9. In the existing hydraulic coupling 9, the control valve needle 94 moves upward and downward It is a cavity formed by butting the inner hole of the upper end of the oil nipple coupling 93 and the center hole of the transition block 95. The lower section of the valve stem 6 is in clearance fit with the center hole of the transition block 95. There is a plane between the oil nipple coupling 93 and the transition block 95. Butt joint seal, so in the actual assembly and use process, the sealing performance of the variable pressure chamber that controls the upward and downward movement of the valve needle 94 is difficult to guarantee, and the stability is poor, which directly affects the opening and closing response speed and stability of the common rail injector , at the same time, the components of the existing hydraulic coupler 9 are complex in structure and poor in manufacturing process

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