SU1469199A1 - Compression piston ring - Google Patents

Abstract

Invention m. used in. engine building. The purpose of the invention is to increase the wiper oil seals by creating a pear-shaped diagram of the radial pressures. The ring 2 has a symmetrical cross section and on its working outer surface 5 obliquely relative to its ends 3 and 4 are undercuts 2. The height of the surface 5 gradually decreases to both sides from the max, the value in the cross section chosen equal to the nominal outgrowth of the ring, to a minimum. values at the ends of the ring. Undercut 2 m. made in the upper and lower outer quadrants of the cross section of the ring, and one bore can be. performed in the middle of the ring height. The angle of inclination b of the undercuts is chosen from the ratio / 3: arctg x X (H (c1.-1) / 2 o (D, where H is the nominal ring size, ai is the specified increase rate of the radial pressure at the ends of the ring compared to the pressure in around the back, D is the nominal diameter of the ring. The ends of the ring are pressed against the sleeve with a higher pressure than in other sections, which provides less penetration of oil into the combustion chamber near the ends of the ring. L with:

Description

J 2

O5 UD

SO About

FIG. I

This invention relates to machine building, in particular to engine building,

The purpose of the invention is to increase the retaining properties of piston seal rings by creating a pear-shaped radial pressure plot.

FIG. 1 shows a ring, a plan view} in FIG. 2 is the same, side view, in FIG. 3 - section A-Ana of FIG. 1 in FIG. 4 is a section BB in FIG. one; in fig. 5 is a sectional view BB in FIG. one; in fig. 6 is a side view of a ring with a variable area of the working surface obtained by a centrally located single inclined undercut.

The compression piston ring 1 of symmetrical cross section has in the upper and lower outer quadrants of the cross section of the undercut 2 tilted to the ends 3 and 4 of the ring 1 at an angle P, with this the working outer surface 5 is formed, the height of which gradually decreases in both directions along the length rings from the maximum value chosen equal to the nominal height of the ring, in cross section 6 of the backrest to the minimum value at the ends 7 of the ring 1. The magnitude of the angle UZ, which determines the production of a ring with a variable height along the circumference, and atelno, the contact area is found from the ratio: about

HW-i) arctg. -2-5 where the angle between the projection of the shelf

undercut and butt of the ring, N is the nominal height of the ring, mm,

“(- the specified coefficient of increase in the radial pressure at the ends of the ring compared to the pressure in the back region (irregularity coefficient of the pear-shaped diagram of the radial pressure of the ring), D is the nominal diameter of the ring, mm.

Ring 1 with a variable circumference of the height of the working surface 5 can also be obtained by performing one centrally located inclined undercut 2, and the shelves of undercut 8 and 9 are located at an angle f to the ends 3 and 4, the value of this angle can be determined from the ratio

if ;; arctg

(

2s (0

where h is the width of the undercut

in cross-section of the back of the ring, is equal to the allowable width of the cutter to perform the internal heat, mm.

The considered rings are characterized by the specific pressure at the ends of the ring (where the area of contact with the sleeve is minimal). Since they possess the so-called pear-shaped epure of radial: pressure.

I

In the case of a recess with an inclination in the other direction (when the contact area decreases when moving from the ends of the ring to its back), a structure is obtained that has elevated pressures in the region of the back, i.e. The ring has a plot in the form of a block, so it is possible to use rings in two-stroke diesel engines with direct jet blowing through the windows. I

The ring 1 rises to the cylinder bushing mirror by its own elasticity, which occurs when it is compressed to the nominal diameter, and, when reciprocating along with the piston, ensures the removal of excess oil on the sleeve. The magnitude of the elastic forces per unit length of the ring is almost the same (the difference is no more than 6%) in all sections of the ring, while the radial pressure per unit of contact surface is significantly differentiated along the circumference: in the back area, where the height of the working surface maximum, specific pressures are minimal, and at the ends of the ring, where the height of the working surface is minimal, the resulting specific pressures are maximum. As practice has shown, engines equipped with compression piston rings with a pear-shaped plot of pressure have higher economic performance due to lower oil consumption for burning as a result of less penetration of oil into the combustion chamber at the ends of the ring sections, pressure to the sleeve.

Claims (5)

Claim 1. Compression piston ring of symmetrical cross section with at least one undercut on its working surface, characterized in that, in order to improve the oil wiping properties by creating a pear-like plot, radial pressure, undercut is slope but relative to one of the ends of the ring, with the height of the outer working cylindrical surface gradually decreasing in both directions from the maximum value in cross section to the minimum value at the ends of the ring. 2. The ring of claim 1, in accordance with claim 1, that the recesses are made in the upper and lower outer quarts of the cross section of the ring. 3. The ring of claim 1, in connection with the fact that the recess is made in the middle of the height of the ring. 4. The ring according to claim 1, characterized in that the maximum height of the working surface is chosen equal to the nominal height of the ring. 5.Ring on PP. 1 and 2, characterized in that the value of the angle of inclination of the undercuts is selected from cojb, arctg ) de / 3 - the angle between the projection of the shelf of the undercut and the end of the ring, H is the nominal height of the ring, mm  - the specified coefficient of increase in the radial pressure at the ends of the ring compared to the pressure in the back area, D is the nominal diameter of the ring, mm. . I L-4 FU8.J 13 (put.S Compiled by A.Gladkikh Editor L.Pcholinska Tehred M.Hodanich Corrector M.Vasilyeva Order 1337/39 Circulation 482 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 B C FIG. S Subscription