Power Tool

Abstract

A power tool is driven by a two-stroke engine. The two-stroke engine has a cylinder and a piston reciprocating within the cylinder. The cylinder has a combustion chamber delimited by the piston. The two-stroke engine has a crankcase and a crankshaft rotatably supported in the crankcase and driven by the piston with a connecting rod. The two-stroke engine has one or more transfer passages connecting the crankcase to the combustion chamber in at least one position of the piston. The two-stroke engine has a mixture passage that is connected to a piston-controlled mixture intake provided at the cylinder and supplies a fuel/air mixture. The combustion chamber has an exhaust port provided within the cylinder. The two-stroke engine has a transverse plane dividing the cylinder parallel to and along the longitudinal cylinder axis. The exhaust port and the mixture intake are arranged on the same side of the transverse plane.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side view of a power tool according to the invention.

FIG. 2 is a schematic longitudinal section view of the two-stroke engine.

FIG. 3 is a section view of the cylinder of the two-stroke engine along section line III-III of FIG. 2 showing the piston at the top dead center.

FIG. 4 is a perspective schematic illustration of the two-stroke engine.

FIG. 5 is a side view of the two-stroke engine of FIG. 4 showing the carburetor arranged thereat.

FIG. 6 is an end view of the two-stroke engine in the direction of arrow VI of FIG. 5.

FIG. 7 is an end view of the two-stroke engine in the grip housing of the power tool viewed in the direction of arrow VII of FIG. 1.

Claims

1. A power tool comprising: a working tool;a two-stroke engine driving the working tool;the two-stroke engine comprising a cylinder and a piston reciprocating within the cylinder in a direction of a longitudinal cylinder axis, wherein the cylinder has a combustion chamber delimited by the piston;the two-stroke engine comprising a crankcase and a crankshaft rotatably supported in the crankcase about an axis of rotation, wherein the piston drives with a connecting rod the crankshaft;the two-stroke engine having one or more transfer passages connecting the crankcase to the combustion chamber in at least one position of the piston;the two-stroke engine comprising a mixture passage supplying a fuel/air mixture, wherein the cylinder has a mixture intake that is connected to the mixture passage and is piston-controlled;wherein the combustion chamber has an exhaust port provided within the cylinder;wherein the two-stroke engine has a transverse plane dividing the cylinder parallel to the longitudinal cylinder axis into a first half and a second half, wherein the longitudinal cylinder axis is located within the transverse plane;wherein the exhaust port and the mixture intake are arranged on the first half of the cylinder.

2. The power tool according to claim 1, wherein the mixture intake is arranged adjacent to the exhaust port on a side of the exhaust port facing the crankcase.

3. The power tool according to claim 1, wherein the two-stroke engine has an air passage that supplies combustion air, wherein the cylinder has an air intake and the air passage is connected to the air intake, wherein the air intake is arranged on the second half of the cylinder.

4. The power tool according to claim 3, wherein the one or more transfer passages each have a transfer port opening into the combustion chamber, wherein the piston has a piston recess, and wherein the air passage is connected through the piston recess in at least one position of the piston to at least one of the transfer ports of the one or more transfer passages.

5. The power tool according to claim 4, wherein the air intake of the cylinder is the only connection of the air passage into the cylinder, wherein the piston recess in at least one position of the piston is connected to all of the transfer ports of the one or more transverse passages.

6. The power tool according to claim 5, wherein the air passage opens in a central area of the piston recess relative to a circumferential direction of the piston.

7. The power tool according to claim 4, wherein the two-stroke engine has a center plane dividing the exhaust port, wherein on either side of the center plane at least one of the one or more transfer passages is arranged.

8. The power tool according to claim 8, wherein a main flow direction of the exhaust port is parallel to the center plane.

9. The power tool according to claim 8, wherein the center plane is perpendicular to the transverse plane, wherein the longitudinal cylinder axis and the axis of rotation of the crankshaft are located within the center plane.

10. The power tool according to claim 3, wherein the air passage and the mixture passage each extend completely on opposite sides of the transverse plane.

11. The power tool according to claim 3, wherein the two-stroke engine has a carburetor in which the fuel/air mixture is generated and in which a throttle element is pivotably supported, wherein the two-stroke engine further comprises an air passage component provided with an air passage section, wherein a choke is pivotable supported in the air passage component, wherein the carburetor and the air passage component are arranged at the level of a cylinder head of the cylinder.

12. The power tool according to claim 1, comprising a power tool housing and an top handle that extends across a top side of the power tool housing, wherein the two-stroke engine is arranged in the power tool housing such that the transverse plane of the two-stroke engine is parallel to the top handle.

13. The power tool according to claim 12, wherein the carburetor is arranged on a side of the cylinder that is facing the top handle.

14. The power tool according to claim 12, wherein the two-stroke engine is arranged substantially horizontally in the power tool housing.

15. The power tool according to claim 1, wherein the axis of rotation of the crankshaft extends perpendicularly to the transverse plane.