A wear-resistant fuel injection pump plunger pair with lubricating structure

Abstract

The invention discloses a wear-resisting oil injection pump plunger and barrel assembly of a lubricating structure. The wear-resisting oil injection pump plunger and barrel assembly comprises a sleeve and a plunger, wherein a plunger cavity is formed in the sleeve, the plunger is assembled into the plunger cavity of the sleeve in a ground mode, fuel oil holes coaxially and radially penetrating through the plunger cavity of the sleeve are formed in the sleeve at 180-degree intervals, two annular lubricating oil grooves are vertically formed in the plunger cavity in a spaced mode, the two annular lubricating oil grooves are each provided with a lubricating oil way communicated to the outer circumferential face of the sleeve, a sleeve positioning pit is manufactured in the outer circumferential face of the sleeve, the central axis of the sleeve positioning pit and the central axes of the fuel oil holes are located on the same plane and perpendicularly intersect with the central axis of the plunger cavity, the sleeve has a surface nitriding layer and a core hardness layer, the whole surface nitriding layer is obtained by the adoption of the nitriding treatment technology, the core hardness layer is located below the surface nitriding layer, the depth of the surface nitriding layer is larger than or equal to 0.4 mm, the surface hardness HV ranges from 900 to 1100, and the hardness HB of the core hardness layer ranges from 235 to 280. The wear-resisting oil injection pump plunger and barrel assembly has the advantages of being accurate in oil supply, simple in structure, easy to manufacture, good in sealing performance and long in service life and can meet the using requirement of a medium-speed diesel engine.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to a fuel injection pump plunger coupling used in a medium-speed diesel engine, in particular to a wear-resistant fuel injection pump plunger coupling with a lubricating structure. Background technique [0002] The plunger coupling of the fuel injection pump is called the heart of the diesel engine. Its main function is to supply high-pressure diesel to the fuel injector at regular intervals to obtain good spray quality. The fuel supply per cycle of the fuel injection pump mainly depends on the effective stroke of the plunger. The larger the stroke, the more fuel is supplied, and vice versa. The main principle is to change the effective stroke by turning the plunger to meet the needs of diesel engine load changes. . The total stroke of the plunger movement of the plunger fuel injection pump remains unchanged. The start time of fuel supply is controlled by the time when the upper ed...

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Problems solved by technology

[0003] The plunger coupling of the fuel injection pump in the prior art is prone to thermal deformation during use, causing the plunger to seize and other phenomena, thus affecting the service life of the plunger, and its processing and manufacturing are also relatively complicated, resulting in low production efficiency and low manufacturing efficiency. high cost

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