RU184035U1 - PISTON OF THE DIESEL ENGINE OF INTERNAL COMBUSTION - Google Patents

Abstract

The utility model relates to the field of engine building, namely to piston designs and can be used as part of diesel internal combustion engines.

For KAMAZ engines of class EURO 0 and EURO 1, a piston is proposed for an internal combustion engine having a head with a combustion chamber in the bottom, grooves for two compression rings and one oil scraper ring and two valve selections, a skirt with an internal cavity and two bosses located in the cavity of the skirt made with holes for the piston pin and grooves for the locking rings, as well as through holes in the skirt for draining oil, characterized in that the groove for the oil scraper ring is made with a nominal height of "B" = 4.99 mm, and the outer turn NOSTA bridges over the groove and the outer surface of the skirt directly beneath the groove has underestimation "T" = 0.9 mm with respect to the radius of the maximum diameter of the piston, the length of understating "C" in both directions at least 3 mm from the top and bottom edges of the grooves.

The set of essential features of the utility model has increased the reliability and durability of the piston by reducing the axial clearance between the oil scraper ring and the groove, as well as improved removal of excess oil from the inner surface of the cylinder liner, resulting in a reduction in oil consumption for burning up to 0.05%. Also, due to the reduction of the axial clearance, linear deformations of the oil scraper ring during engine operation are minimized (the ring bends less and is more perpendicular to the liner surface, the working surface of the ring produces more uniform oil removal), which leads to an increase in the reliability and reliability of the engine as a whole . 3 ill.

Description

The utility model relates to the field of engine building, namely to piston designs and can be used as part of diesel internal combustion engines.

The closest to the claimed technical solution in terms of the set of essential features and the technical result achieved is a piston for an internal combustion engine containing a head with a combustion chamber in the bottom with a displacer and grooves for compression and oil rings, a skirt with bosses having an internal cavity above the holes for the piston pin made with grooves for circlips, oil drain holes. The nominal height of the groove under the oil scraper ring is 5 mm (see utility patent RU 104246, IPC F02F 3/02, published May 10, 2011).

A disadvantage of the known technical solution is that the declared nominal height for oil scraper rings have a disadvantage in terms of excessive gaps between oil scraper rings and the surfaces of grooves for oil scraper rings, which in turn negatively affects the running-in of piston rings. Excessive clearances contribute to the deformation of the piston body in the region of the upper and lower plane of the groove due to the shifting of the ring in the groove during engine operation, inefficient removal and removal of oil into the crankcase, which leads to the penetration of oil into the combustion chamber, the formation of soot in the grooves and, as a consequence of a decrease in the reliability and resource of the piston.

The proposed technical solution is aimed at improving the reliability and durability of the piston for a diesel internal combustion engine by optimizing the axial clearance between the planes of the groove and the planes of the oil scraper ring.

The proposed piston option for a diesel internal combustion engine can be manufactured on existing equipment using known technology. Other solutions of a similar purpose with similar essential features when conducting a search in the scientific and technical literature and patent documentation were not found by the applicant. Therefore, the applicant believes that the proposal for this application meets the eligibility criteria of the utility model “novelty” and “industrial applicability”.

For KAMAZ engines of class EURO 0, EURO 1, a piston is proposed for an internal combustion engine having a head with a combustion chamber in the bottom, grooves for two compression rings and one oil scraper ring and two valve selections, a skirt with an internal cavity and two bosses located in the cavity of the skirt made with holes for the piston pin and grooves for the snap rings, as well as through holes in the skirt for draining oil, characterized in that the groove for the oil scraper ring is made with a nominal height of "B" = 4.99 mm, and the outer turn The jumper over the groove and the outer surface of the skirt directly below the groove has an understatement of "T" = 0.9 mm per radius relative to the maximum diameter of the piston. The length of the understatement “C” in both directions is at least 3 mm from the upper and lower edges of the groove.

During engine operation, the pistons reciprocate in the cylinder liners, while oil is sprayed from the crankcase into the lower part of the pistons and onto the inner surface of the cylinders to ensure lubrication of the liner-piston pair. The oil scraper ring is designed to remove excess oil from the inside of the cylinder liner. Due to the groove under the oil scraper ring with a nominal height “B” = 4.99 mm, the gap between the planes of the groove and the planes of the scraper ring is reduced, which in turn leads to minimal ring shifting during the reciprocating movement of the piston in the cylinder. Minimal shifts prevent deformation of the groove, which increases the reliability and durability of the piston.

During engine operation, the piston and piston rings are subjected to thermal and dynamic loads, under the influence of which the materials of which the piston and rings are made have linear extensions. As a rule, pistons are made of silumins, and piston rings, including the oil scraper ring, are made of modified cast iron. The working temperature of the CPG, during normal engine operation, is about 250 ° C. At this temperature, the linear expansion of the material of which the piston (silumin) is made will be a maximum of 0.12 mm for every 100 mm.

At the same temperature, the linear expansion of the cast iron rings will be no more than 0.0011 mm for every 100 mm. Due to the rather small value of the linear expansion of the rings, in further calculations they can be neglected.

The main objective of the proposed solution is to minimize the axial clearance between the oil scraper ring and the groove, which will allow to avoid deformation of the piston body during shifting of the ring during engine operation.

The proposed technical solution takes into account the standard design of oil scraper rings, which are available on the market, due to which changes in the piston design will not lead to a change in the product line of rings and negative feedback from consumers.

It is known that the standard height in the performance of oil scraper rings for KAMAZ engines of the environmental class EURO 0 and EURO 1 is from 4.970 mm to 4.990 mm. Those. at room temperature, the maximum ring-piston clearance is 0.020 mm.

Given the linear temperature expansion of the piston, which will be 0.006 mm to the height of the groove under the oil scraper ring at the engine operating temperature, the minimum clearance will be 0.006 mm and the maximum 0.026 mm, which eliminates large axial displacements of the ring.

To effectively remove excess oil, this solution proposes an understatement of "T" = 0.9 mm per radius relative to the maximum diameter of the piston above and below the groove for the oil scraper ring, length "C" of at least 3 mm, ensuring the presence of cavities for excess removed from the inner surface of the cylinder liner oil. When the piston moves in the direction of top dead center, oil, through the oil scraper ring, is removed from the inner surface of the cylinder liner and accumulates in the cavity above the oil scraper ring groove, and then, through the provided gap between the ring plane and the groove plane, flows into the engine crankcase through holes in the piston skirt.

When the piston moves in the direction of bottom dead center, oil from the inner surface of the cylinder liner accumulates in the cavity under the groove under the oil scraper ring, and then also flows through the gap into the crankcase through the through holes in the piston skirt.

The set of essential features of the utility model made it possible to increase the reliability and durability of the piston by reducing the axial clearance between the oil scraper ring and the groove, as well as improved removal of excess oil from the inner surface of the cylinder liner, as a result of reducing oil consumption for burning up to 0.05%. Also, due to a decrease in the axial clearance, linear deformations of the oil scraper ring during engine operation are minimized (the ring works less bending and is more perpendicular to the surface of the liner, the working surface of the ring produces more uniform oil removal), which leads to an increase in the reliability and reliability of the engine in whole.

The claimed technical solution is illustrated by the drawings:

FIG. 1 - sectional view of a piston of an internal combustion engine;

FIG. 2 is a view A in FIG. one;

FIG. 3 - piston of an internal combustion engine, top view.

A piston (Fig. 1) for an internal combustion engine having a head 1 with a combustion chamber 2 in the bottom 3, grooves 4 and 5 for two compression rings and a groove 6 for the oil scraper ring, two samples 7 for the valve (Fig. 3), skirt 8 with an internal cavity 9 and two bosses 10 located in the cavity of the skirt, made with holes 11 for the piston pin and grooves for the snap rings (not shown), as well as through holes 12 in the skirt 8 for draining the oil. The groove under the oil scraper ring (Fig. 2) is made with a nominal height "B" = 4.99 mm. The outer surface of the jumper 13 above the groove 6 and the outer surface of the skirt 8 directly below the groove 6 has an understatement of "T" = 0.9 mm per radius relative to the maximum diameter of the piston. The length of the understatement “C” in both directions is at least 3 mm from the upper and lower edges of the groove. Understatements form two cavities, the lower 14 and the upper 15, for the accumulation of excess oil, limited to the surfaces of the piston, oil scraper ring 16 and the inner surface 17 of the cylinder liner.

Claims (1)

A piston for an internal combustion engine having a head with a combustion chamber in the bottom, grooves for two compression rings and one oil scraper ring and two valve samples, a skirt with an internal cavity and two bosses located in the cavity of the skirt, made with holes for the piston pin and grooves under retaining rings, as well as through holes in the skirt for draining oil, characterized in that the groove for the oil scraper ring is made with a nominal height "B" = 4.99 mm, and the outer surface of the jumper above the groove and the outer surface s skirt directly beneath the groove has underestimation "T" = 0.9 mm with respect to the radius of the maximum diameter of the piston, and the length of understating "C" in both directions at least 3 mm from the top and bottom edges of the grooves.

Images