Marine diesel guiding valve type pintle nozzle matching parts

Abstract

The present invention discloses a slide valve type pin valve coupling of a marine diesel engine, which comprises a pin valve body, a pin valve, a thrust block seat, a spout and a fastener which are suitably assembled together; wherein, the pin valve, the front part of which is extended into the cavity of the spout via the front hole of the pin valve body, is arranged in the cavity of the pin valve body in clearance fit; the rear cavity of the pin valve is in interference fit with the periphery of the front part of the thrust block seat in a sliding way; the front part of the pin valve is in interference fit with the spout in a sliding way; the rear part of the thrust block seat is provided with a lug boss, which is in interference fit with the rear end surface of the pin valve body; the assembling position of the spout is determined by the fastener; the pin valve can directly shut the spray hole of the spout by shutting a high-pressure oil circuit and can prevent the spray hole of the spout from being blocked by carbonized residue fuel oil in the cavity of the spout to the maximum extent; high-pressure diesel oil is sealed in a cavity formed by the pyramidal surface of the pin valve and the seat surface of the pin valve body. The pin valve coupling, which can meet the requirement of the marine diesel engine on the pin value coupling of an oil atomizer, has the advantages of ingenious structure, small volume, good performance, low oil consumption, little discharge, strong reliability, little carbon deposit in the spout, long service life of the spout, etc.

Description

technical field [0001] The invention relates to the technical field of marine diesel engines, in particular to a sliding valve type needle valve coupling of marine diesel engines. Background technique [0002] The fuel injector is an important component of the diesel engine. Its main function is to atomize the high-pressure diesel oil from the fuel injection pump according to certain requirements, and distribute it into the combustion chamber to form a good combustible mixture. As the core of the injector assembly, the needle valve coupler is a pair of precision couplers. The guide cylindrical surface on the upper part of the needle valve and the inner cylindrical surface of the needle valve are in high-precision sliding fit. The clearance is about 0.004mm to 0.006mm. The roughness reaches Ra0.025μm. The tapered surface in the middle of the needle valve cooperates with the seat surface on the needle valve body to act as a seal. When the oil pressure reaches the opening pres...

AI Technical Summary

Problems solved by technology

Because there is a certain space between the nozzle and the sealing cone in the existing needle valve assembly, a small amount of fuel is likely to remain in the nozzle, and it is easy to block the nozzle hole after carbonization

The diameter of the nozzle hole is generally about 0.5-1.0mm. Under the action of high-pressure oil mist in a high-temperature working environment, the end of the nozzle hole is prone to corrosion failure, which affects the atomization effect of fuel.

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