SU1204767A1 - Piston for internal combustion engine - Google Patents

Description

The invention relates to mass structure, namely to engine building (mainly to internal combustion engines), and is intended for use in thin-walled cast iron pistons of forced diesel engines.

The purpose of the invention is to increase reliability and durability by increasing the rigidity of the piston head.

Fig, 1 shows a piston, a general view; FIG. 2 is a section A-A in FIG. 1,

The piston comprises a housing 1 with a combustion chamber 2, formed in the bottom 3, connected with bobs 4, mutually perpendicular stiffening ribs 5 and 6.

The inner surface of the bottom 3 is made in the form of a paraboloid of rotation with a vertex located at the intersection of the vertical axis 7 of the piston with the inner surface of the bottom 3 and forming, executed in accordance with the dependence

xf y, -,

where y is the vertical coordinate

points on the surface of the paraboloid from the plane of reference 8, passing through the vertex of the paraboloid of rotation, perpendicular to the axis 7 of the piston;

the horizontal coordinate of a point on the surface of the paraboloid;

coefficient of proportionality, equal to 175, Mutually perpendicular ribs 5 and 6 of rigidity are made in the st; e parabolas 8 of the form

.

(

X, and. where y is the vertical coordinate of the parabola point, X2 is the horizontal1 on the coordinate

points of a parabola, h - constant, equal to 2 n: 4; aj is a proportionality coefficient equal to 4300, the tops of the parabolic 9 iie6ep 5 and 6 stiffness are connected to the top of the paraboloid, and the thickness of the bottom 3 from the center to the periphery of the combustion chamber 2 satisfies the condition

h

h

"/ 2 /

h where r

h.

the ratio of the thickness of the bottom 3 at the periphery to the thickness in the center, equal to 1.05-1.3 base of natural logarithm,

 - exponent exponent equal to 0,, 0073; - the coordinate on the generator of the paraboloid of rotation of the inner surface of the bottom 3 is equal to 35 ,,

The stiffener 5 is connected to the flat edge 0 and the bob 4, and the rib 6 is connected to the core of the piston rings 1 1, the skirt of the piston 12 and the bottom 3 of the piston.

When the engine is operating, the forces of pressure of gases and inertia of progressively moving masses acting on the days of the piston 3 are transmitted to the walls of the boss 4 through the piston rings 11, the stiffeners 5, 6, 10 and the piston skirt 12,

The bottom 3, the inner surface of which is made in the form of a paraboloid of rotation with the top in the center of the bottom and forming the form

2 X,

U1

reduces meridional, circumferential forces and in combination with mutually perpendicular stiffening ribs 5 and 6, made in the form of parabolas of the form

45

2

/ one /

/ X2 /

reduces the intensity of the stresses in the zone of connection of the fins 5 and 6 with the bottom 3, the thickness of which from the center to the periphery of the combustion chamber 2 satisfies the following condition

h h.

tt / 2 /

-e

ensures reliable operation of the piston by eliminating the appearance of fatigue cracks on the surface of the combustion chamber.

fig.i

Compiled by V.Lobanov Editor M.Tovtin Tehred A. Babinets

Order 8503/32 Circulation 537 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d, 4/5

Branch 1ShP Patent, Uzhgorod, st. Project, 4

FI.2

Proofreader L. Patay

Claims (4)

I. PISTON FOR THE INTERNAL-COMBUSTION ENGINE, containing a housing with a combustion chamber made in its bottom and bosses connected to the inner surface of the bottom with mutually perpendicular stiffeners, characterized in that, in order to increase reliability, the inner surface of the bottom is made in the form of a paraboloid rotation with a vertex located at the intersection of the vertical axis of the piston with the inner surface of the bottom, and a generatrix made in accordance with the dependence X * Uss; ⁵ where is the vertical coordinate of a point on the surface of the paraboloid from the reference plane passing through the vertex of the paraboloid of rotation perpendicular to the axis of the piston; ¹ 'x, is the horizontal coordinate of the point on the surface of the paraboloid', and, is the proportionality coefficient equal to 175, 2. The piston in π. 1 of the Lich t u u · d and with me in that the inner surface- mutually perpendicular edges gkestkosti made a parabola in:, tsa "/ 2 'and _x' where - the vertical coordinate of the point of the parabola;? X _g is the horizontal coordinate of the parabola point, 2i p - 4; - coefficient proportional to direct 4300. 3. The piston according to paragraphs. 1-2, with the fact that the vertices of the parabolas of the stiffeners and the vertex of the paraboloid of rotation are combined with each other, 4. The piston according to paragraphs. 1-3, due to the fact that the thickness of the bottom from the center to the periphery of the combustion chamber increases from the center to the bottom 3 h where m -> 0 in accordance with the relation m -, ¹ 'P - the ratio of the thickness of the bottom on the periphery to the thickness. in the center, equal to 1.05-1.3; u - exponent, Ο, ΟΟ25έο <£ 0.0073; Ζ - coordinate on the generatrix of the paraboloid of rotation 35.9 * ^ 37; C is the basis of the natural logarithm.