Piston for internal combustion engine

Abstract

The invention discloses a piston for an internal combustion engine. The piston for high rotation is formed through lighter weight and compactness. A first air ring groove 2 and an oil ring groove 4 are formed around the crown 1, and an oil supply hole 5 is provided inside the oil ring groove 4, and a pair of air ring grooves 5 are arranged at positions opposite to the bottom of the crown 1 continuously. The piston pin seat 6 is provided with a skirt 7 staggered by 90 degrees from the piston pin seat 6, the lower end 12 of the skirt 7 is located above the lower end 11 of the piston pin 6, and on the upper part of the skirt 7, the oil An oil supply hole 10 is provided below and near the ring groove 4 .

Description

technical field [0001] The present invention relates to a piston for an internal combustion engine, and more particularly to a piston for an internal combustion engine suitable for high rotational speed and compactness. Background technique [0002] Existing pistons for internal combustion engines have a crown, a piston pin seat integrally formed with the crown, and a pair of skirts oppositely arranged, and grooves for piston rings are formed around the crown (as an example, refer to Japan Real Fair 7-7570). FIG. 6 shows such a conventional structure. A first air ring groove 2, a secondary ring groove 3, and an oil groove 4 are arranged around the crown portion 1, and piston rings omitted from the figure are respectively fitted in them. The bottom of the oil ring groove 4 is formed with an oil supply hole 5 penetrating inside and outside. [0003] Reference numeral 6 is a piston pin seat portion, 7 is a skirt portion, and the lower end of the skirt portion 7 extends downwa...

AI Technical Summary

Problems solved by technology

[0005] However, when the lower part of the skirt 7 protrudes much downward as in the example of the prior art as described above, the weight is increased by it, and therefore, there is a problem that it hinders the high rotation speed or compactness of the engine.

The same problem also exists when the circumferential width of the skirt is large

[0006] In addition, if sufficient lubrication cannot be provided even if an oil supply hole is provided on the bottom of the oil ring groove, the friction between the piston and the cylinder will become severe, and sometimes the piston will be stuck or burnt.

[0007] In addition, although the step portion 8 for machining reference is provided at the lower portion of the skirt portion 7, under the condition that the skirt portion 7 is subjected to a high load, the step portion 8 may become a starting point of fracture due to stress concentration.

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