Handheld engine-driven working machine
AssigneeYamabiko Corporation
InventorsKuniyoshi ETO, Masayoshi MIYAMOTO
Life of this patent
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Abstract
A handheld engine-driven working machine comprises an internal combustion engine and an ignition control device; wherein the ignition control device can switch its control between a normal mode and a operation mode, wherein during the operation mode, the ignition timing within the high speed range is maintained at a second BTDC angle, and the ignition timing within the medium speed range is advanced more than a third BTDC angle between a first BTDC angle and the second BTDC angle, and wherein at any rotational speed within the medium speed range, the ignition timing during the operation mode is advanced more than the ignition timing during the normal mode.
Claims8
A handheld engine-driven working machine comprising:
- an internal combustion engine which includes a cylinder, a crankshaft, a piston disposed in the cylinder and connected to the crankshaft, and an ignition plug disposed in an upper portion of the cylinder;
- and
- an ignition control device activating the ignition plug;
- wherein the ignition control device can switch its control between a normal mode and an operation mode,
- wherein during the normal mode, the ignition timing within a medium speed range is advanced from a first BTDC angle to a second BTDC angle as the rotational speed increases and the ignition timing within a high speed range is maintained at the second BTDC angle,
- wherein during the operation mode, the ignition timing within the high speed range is maintained at the second BTDC angle and the ignition timing within the medium speed range is advanced more than a third BTDC angle between the first BTDC angle and the second BTDC angle, and
- wherein at any rotational speed within the medium speed range, the ignition timing during the operation mode is advanced more than the ignition timing during the normal mode.
Dependencies are inferred from the claim text.