RU2007602C1 - Piston for internal combustion engine - Google Patents

Abstract

FIELD: engine engineering. SUBSTANCE: piston has head with heat belt and grooves for compressing and oil catch rings and skirt profiled so that a ratio of diametrical deviations from nominal diameter of the piston at the top edge of the heat belt, at bottom edge of the first inter- crank crosspiece, at the top zone of the skirt, at the bottom edge of the skirt to diameter of the cylinder at a given value of a distance from the bottom of the piston to nominal diameter result in optimization of the profile of side surface of the piston. Characteristic parameters for engines with spark ignition and Diesels are available separately. EFFECT: improved design. 4 cl, 1 dwg

Description

 The invention relates to mechanical engineering, in particular to engine building, and can be used in the design of pistons of an internal combustion engine (ICE).

 Known pistons of the internal combustion engine containing a head with grooves for compression and oil scraper ring, and a skirt. Moreover, the outer surface of the piston, based on ensuring the operability of the structure in the entire speed and load ranges of the internal combustion engine, gives a very definite configuration (oval-conical, oval-barrel-shaped, etc.).

 The closest technical solution to the proposed one is the piston of an internal combustion engine containing a head with a heat belt and grooves for compression and oil scraper rings, and a skirt with a profiled oval-barrel-shaped working surface.

 The disadvantage of this design, as well as the design of similar types of pistons, is that despite attempts to optimize the profile of the piston working surface by setting its geometrical parameters, it is not possible to sufficiently reduce fuel and engine oil consumption, noise and toxicity.

 The aim of the invention is to increase fuel efficiency, reduce oil consumption for waste, noise and toxicity of exhaust gases, both for spark ignition engines and for diesel engines.

The technical result expressed in the purpose of the invention is achieved due to the fact that in the piston of the internal combustion engine containing a head with a heat belt and grooves for compression and oil scraper rings and a skirt with a profiled oval-barrel-shaped working surface, the geometric parameters of the head and skirt of the piston are made in accordance with the ratios : Δ ₁ / D _c = = (2.6-4.85) ˙10 ^-3 , Δ ₂ / D _c = (0.95-3.25) ˙ 10 ^-3 , Δ ₃ / D _c = (0 , 74-1.84) ˙10 ^-3 , Δ ₄ / D _c = (0.08-0.4) ˙10 ^-3 , N _o / D _c = (0.6-0.9), where Δ ₁ - diametrical deviation in the upper edge of the flame belt from the nominal diameter of the piston, mm;
Δ ₂ is the diametrical deviation in the lower edge of the first inter-annular jumper from the nominal diameter of the piston, mm;
Δ ₃ - diametrical deviation in the upper zone of the skirt from the nominal diameter of the piston, mm;
Δ ₄ - diametrical deviation in the lower edge of the skirt from the nominal diameter of the piston, mm; _N D - diameter of the cylinder, mm;
N _about - the distance from the piston bottom to the zone of the maximum diameter of the piston.

In addition, for engines with spark ignition, the following parameter can be additionally changed, namely, the ratio of the height of the flame belt N _g to the cylinder diameter D _c can be selected in the range 0.05-0.059.

 For diesel engines, this parameter can be made equal to 0.091-0.19.

 The drawing shows a piston with a barrel-shaped surface.

The internal combustion engine piston contains a head 1 with a heat belt 2 and grooves 3 for compression and oil scraper rings (not shown), a skirt 4 with a profiled oval-barrel surface 5. Diametrical deviation Δ ₁ in the upper edge 6 of the fire belt 2 from the nominal piston diameter D _p relative to the diameter of the cylinder Dc is made equal to (2.6-4.85) ˙10 ^-3 . The diametrical deviation Δ ₂ in the lower edge 7 of the first inter-valve jumper 8 from the nominal piston diameter D _p relative to D _{c is} made equal to (0.95-3.25) ˙ 10 ^-3 . The diametrical deviation 3 in the upper zone of the skirt 9 from the nominal diameter D _p with respect to D _{c is} made equal to (0.79-1.84) ˙10 ^-3 . The diametrical deviation Δ ₄ in the upper edge 10 of the skirt from the nominal piston diameter D _p relative to D _{c is} made equal to (0.08-0.4) ˙10 ^-3 . Moreover, to the cylinder _of diameter D _p ratio of the distance H is chosen in the range (0.6-0.9). For engines with spark ignition, an additional profiling parameter is introduced: the ratio of the height of the flame belt N _g to the cylinder diameter D _c , which is selected within the range of 0.05-0.059. For diesel engines, the ratio of H _g / D _c is chosen equal to 0.091-0.19. Deviations Δ ₁ , Δ ₂ , Δ ₃ and Δ ₄ are set without taking into account the presence of chamfers at points 6,7,9 and 10.

 During the operation of the internal combustion engine when the piston moves in the cylinder, complex hydraulic and thermal processes occur between the cylinder and the lateral surface of the piston, leading to the need for profiling the piston and choosing the position of the piston rings.

 The manufacture of pistons with the geometrical parameters described above allows one to take into account the dynamics of oscillations of the piston on the oil layer and its thermal deformation and to obtain products that help reduce mechanical losses in the cylinder-piston group, reduce the so-called harmful volumes and toxicity of gases, reduce the intensity of piston shifting and noise and engine reducing crankcase gas consumption and increasing fuel and oil efficiency.

 For example, tests of experimental pistons made in accordance with the invention, compared with pistons of the VAZ-1111 engine, showed a decrease in the specific effective fuel consumption of 6.. . 12%, increase in torque by 10.. . 15%, noise reduction by 2.5. . . 3 dB and oil consumption for waste by 10%. (56) Orlin A.S. Design and calculation of piston and combined engines. M.: Mechanical Engineering, 1984, p. 123-126.

Claims (4)

1. A PISTON FOR THE INTERNAL COMBUSTION ENGINE, comprising a head with a heat belt and grooves for compression and oil scraper rings and a skirt with a profiled oval-barrel-shaped working surface, characterized in that the geometric parameters of the head and skirt are made in accordance with the ratios
Δ ₁ / D _c = (2.6 - 4.85) · 10 ^-3 ;
Δ ₃ / D _c = (0.79 - 1.84) · 10 ^-3 ;
Δ ₄ / D _c = (0.08 - 0.4) · 10 ^-3 ;
H _o / D _c = (0.6 - 0.9),
where Δ ₁ is the diametrical deviation in the upper edge of the flame belt from the nominal diameter of the piston, mm;
Δ ₃ - diametrical deviation in the upper zone of the skirt from the nominal diameter of the piston, mm;
Δ ₄ - diametrical deviation in the upper edge of the skirt from the nominal diameter of the piston, mm;
D _c - cylinder diameter;
H ₀ is the distance from the piston bottom to the zone of nominal diameter. 2. The piston according to claim 1, characterized in that the ratio of the diametrical deviation in the lower edge of the first inter-annular jumper from the nominal piston diameter Δ ₂ to the cylinder diameter D _c is equal to (0.95 - 3.25) · 10 ^-3 . 3. The piston according to paragraphs. 1 and 2, characterized in that the ratio piston top land height H _r to the cylinder diameter D _n is satisfied at 0.05 - 0.059. 4. The piston according to paragraphs. 1 and 2, characterized in that the ratio of the height of the flame belt H _g to the cylinder diameter D _{c is} made equal to 0.091 - 0.19.

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