Engine piston, engine, hand-held tool, and method of manufacturing engine piston

Abstract

A two-stroke engine piston (1) is disclosed comprising a piston top (3), a mantle surface (5), a stratified scavenging channel (7) in the mantle surface (5), and a weight reduction space (9) arranged between the piston top (3) and the stratified scavenging channel (7). The weight reduction space (9) has a largest first axial extent (a1) at the mantle surface (5) and a second axial extent (a2) radially inside the mantle surface (5), and wherein the second axial extent (a2) is greater than the largest first axial extent (a1). The present disclosure further relates to an engine (30), a hand-held tool (40), and a method of manufacturing an engine piston (1).

Description

technical field

[0001] The invention relates to a piston for a two-stroke engine including a space for weight reduction. The invention also relates to a two-stroke engine comprising a piston, a hand-held tool comprising a two-stroke engine, and a method of manufacturing an engine piston. Background technique

[0002] A two-stroke engine is an internal combustion engine that completes the power cycle through two strokes of the piston during one revolution of the crankshaft. The highest position of the piston in the cylinder is usually called top dead center, and the lowest position of the piston in the cylinder is usually called bottom dead center. Compared with four-stroke engines, two-stroke engines have a greatly reduced number of moving parts, so they can be made more compact and lighter. Therefore, two-stroke gasoline engines are used in applications where mechanical simplicity, low weight and high power-to-weight ratio are the main concerns. Typical applications are ...

Examples

Embodiment Construction

[0074] Aspects of the invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions are not necessarily described in detail for brevity and / or clarity.

[0075] figure 1 A perspective view of a two-stroke engine piston 1 according to some embodiments is shown. For the sake of brevity and clarity, the two-stroke engine piston 1 is referred to as "piston 1" in some places herein. Piston 1 includes a piston crown 3 . When the piston 1 is arranged in the engine cylinder, the piston top 3 is arranged facing the cylinder head of the engine cylinder of the two-stroke engine. The piston crown 3 is arranged to define a combustion chamber together with the cylinder walls of the engine cylinder. Thus, the piston crown 3 is arranged to be in contact with hot combustion gases during the power stroke of the engine comprising the piston 1 . Furthermore, the piston 1 comprises a cylindrical mantle surface 5 . The outer...

technical field

[0001] The invention relates to a piston for a two-stroke engine including a space for weight reduction. The invention also relates to a two-stroke engine comprising a piston, a hand-held tool comprising a two-stroke engine, and a method of manufacturing an engine piston. Background technique

[0002] A two-stroke engine is an internal combustion engine that completes the power cycle through two strokes of the piston during one revolution of the crankshaft. The highest position of the piston in the cylinder is usually called top dead center, and the lowest position of the piston in the cylinder is usually called bottom dead center. Compared with four-stroke engines, two-stroke engines have a greatly reduced number of moving parts, so they can be made more compact and lighter. Therefore, two-stroke gasoline engines are used in applications where mechanical simplicity, low weight and high power-to-weight ratio are the main concerns. Typical applications are ...

Examples

Embodiment Construction

[0074] Aspects of the invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions are not necessarily described in detail for brevity and / or clarity.

[0075] figure 1 A perspective view of a two-stroke engine piston 1 according to some embodiments is shown. For the sake of brevity and clarity, the two-stroke engine piston 1 is referred to as "piston 1" in some places herein. Piston 1 includes a piston crown 3 . When the piston 1 is arranged in the engine cylinder, the piston top 3 is arranged facing the cylinder head of the engine cylinder of the two-stroke engine. The piston crown 3 is arranged to define a combustion chamber together with the cylinder walls of the engine cylinder. Thus, the piston crown 3 is arranged to be in contact with hot combustion gases during the power stroke of the engine comprising the piston 1 . Furthermore, the piston 1 comprises a cylindrical mantle surface 5 . The outer...

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