Piston for internal combustion engine

Abstract

The invention relates to a piston (1) comprising a piston head (3), a circumferential ignition strip (4) and at least one annular groove (5). What are essential to the invention herein are a first ignition strip portion (7) adjoining the piston head (3), a third ignition strip portion (8) adjoining the annular groove (5), and a second ignition strip portion (9) connecting the two ignition strip portions (7, 8) and arranged therebetween; the first ignition strip portion (7) has an axial height h1, the second ignition strip portion (9) has an axial height h2, and the third ignition strip portion(8) has an axial height h3; the first ignition strip portion (7) has an upper outer diameter D1, the third ignition strip portion (8) has a lower outer diameter D3, and wherein the piston (1) has anouter diameter D12 at a transition portion from the first ignition strip portion (7) to the second ignition strip portion (9) and an outer diameter D23 at a transition portion from the second ignitionstrip portion (9) to the third ignition strip portion (8); the piston is applicable to (D12-D23) / h2> (D23-D3) / h3, and especially can reduce the negative LSPI effect.

Description

technical field [0001] According to the preamble of claim 1, the invention relates to a piston for an internal combustion engine comprising a piston head, a surrounding ignition band and at least one annular groove for receiving a piston ring And adjacent to the ignition zone. Furthermore, the invention relates to an internal combustion engine having at least one such piston. Background technique [0002] Pistons of conventional type are well known, wherein the outer diameter from the piston head to the first annular groove is usually arranged on the fire land of said piston, the gap between the fire land and the cylinder wall being increased due to this outer diameter. Larger and narrower from the piston head to the first annular groove. It goes without saying that cylindrical ignition strips are also known. This can be achieved by means of a conical or cylindrical ignition zone of this type, for example with a larger chamfer at the transition from the ignition zone to t...

AI Technical Summary

Problems solved by technology

[0005] However, in a gap of this type, which narrows between the ignition strip and the cylinder wall from the piston head to the first annular groove, it is disadvantageous that the pressure fluctuations flowing into said gap are further amplified

In some cases, pressure spikes, especially in so-called low speed pre-ignition (LSPI) conditions, are created by said amplified pressure fluctuations, which potentially increase the bursting of the ignition strip upwards and thus into the combustion chamber, Or the risk of a downward rupture of the ignition strip located between the first and second annular grooves, which must be avoided at all costs

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