JPS5943483Y2 - Anti-twist piston ring for internal combustion engines - Google Patents

Description

[Detailed description of the invention] The present invention is installed in a piston ring groove drilled on the outer periphery of a piston ring of the same shape that slides into a cylinder IL having an oval or oval cross section in a cylinder block of an internal combustion engine. related to piston rings.

As such a piston ring, for example, as shown in FIG.
15,016, and both side portions 017,018 which have a smaller curvature than those both ends and smoothly connect to those both ends.
It is formed into an elliptical or oval shape, is cut at one end 015 in the longitudinal direction, has a cutting cut 019, and has a constant cross-sectional shape over the entire circumference. .

In particular, the both side parts 017 and 01B, which have a small curvature and are relatively long, tend to twist around the longitudinal center line as shown in FIG. 6 when subjected to external force during engine operation. Outer peripheral end surfaces S of the both side portions 817, 018
When the enormous gas pressure in the combustion chamber 012 is applied to the combustion chamber 012, the side portions 017 and 018 may be bent inward as shown by the chain lines in FIG. 5, causing a problem of generating a large amount of blow-by gas.

Therefore, the present invention can solve the above-mentioned problems by particularly strengthening the rigidity of the both sides having a small curvature in the oval-shaped piston ring described above.

An object of the present invention is to provide an anti-twist piston ring for an internal combustion engine.

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
A cylinder hole 2 having an oval cross section is formed in the cylinder block 1, and a piston 3 having an oval cross section is slidably fitted into the cylinder hole 2.

A piston pin 4 is horizontally suspended in the longitudinal direction of the piston 3, and the small ends of two connecting rods 5 are connected to the piston pin 4, and the large ends of these connecting rods 50 are connected to the crankshaft 6. Ru.

Note that 5' is another connecting rod connected to the crankshaft 6, and these connecting rods are connected to the piston 3 in another cylinder block 1 (not shown) which is arranged in a V-shape with the cylinder block 1.

A cylinder head 8 is attached to the upper part of the cylinder block 1 via a gasket γ, and a combustion chamber 10 is formed by the combustion chamber wall 9 formed on the lower surface of the cylinder head 8 and the upper surface of the piston 3.

A piston ring groove 11 and an oil ring groove 12 are formed on the outer peripheral surface of the piston 3, and these grooves 11
, 12 are fitted with a piston ring 13 and an oil ring 14, which will be described later.

Next, the structure of the piston ring 13 of the present invention will be explained. FIG. 3 shows the state when the piston ring 13 is installed, and the piston ring 13 has a longitudinal end portion 15.16 formed in an arc shape. their longitudinal ends 15,1
and a straight side 17.18 smoothly connecting to 6;
The overall outer shape is formed into an oval shape, and the longitudinal end portion 1
One of 5 and 16 is cut at the center to form a cut slit 19.

Width W of linear both sides i7, 18 of piston ring 13
S is formed to be larger than the width WC at the center of the arcuate ends 15, 16, and the width of the arcuate end portions 1516 is formed to gradually decrease toward the center.

With this configuration, both sides 1 are straight and have a small curvature.
By particularly strengthening the rigidity of 7.18, additional twisting and bending deformation of the both side portions 17 and 18 can be effectively suppressed.

In the above, a piston ring having an oval-shaped outer shape has been described, but a piston ring has an oval shape having both longitudinal ends with a large curvature and both sides with a smaller curvature and smoothly connecting to the ends. may be formed.

As described above, according to the present invention, a piston ring is attached to a piston ring groove of a piston having a cross section of the same shape and is slidably fitted into a cylinder hole having an oval or oval cross section of a cylinder block of an internal combustion engine. , formed into an oval or oval shape having both ends in the longitudinal direction having a large curvature and both sides having a smaller curvature than both ends and smoothly connected to the both ends, and cutting at one end in the longitudinal direction. A cutting cut is formed, and the width of both sides with the small curvature is made wider than the width of the longitudinal end with a large curvature, so that the rigidity of both sides, which have relatively low rigidity, is increased and the radius of curvature is increased. It is possible to particularly strengthen the rigidity of the relatively long both side portions, which have a small diameter, and effectively suppress the twisting and bending deformation of the both side portions during engine operation. It is possible to improve performance.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention. Fig. 1 is a longitudinal cross-sectional view of an internal combustion engine having a piston with an oval cross section equipped with the piston ring of the present invention, and Fig. 2 is a line taken along the line ■-■ of Fig. 1. 3 is a plan view of the piston ring of the present invention, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a plan view of a conventional piston ring, and FIG. 6 is a plan view of a conventional piston ring. FIG. 1... Cylinder block, 2... Cylinder hole, 3... Piston, 11... Piston ring groove, 13... Piston ring, 1
5.16... Both ends in the longitudinal direction, 17, 18...
...Both sides, 19...Cut cut, WC...
... Width at both ends in the longitudinal direction, WS... Width at both ends.

Claims (1)

[Scope of utility model registration request] A piston ring that is installed in a piston ring groove of a piston that has a cross section of the same shape and is slid into a cylinder hole that has an oval or oval cross section of a cylinder block, and in the installed state, both ends in the longitudinal direction are arcuate. It is formed into an oval or oval shape having a curvature smaller than those of both ends and both sides smoothly connected to those ends, and is cut at one of the ends in the longitudinal direction to form a cutting cut. A twist-preventing piston ring for an internal combustion engine, wherein the width of the both sides is larger than the width of both ends in the longitudinal direction.