ENGINE-POWERED WORK TOOL PROVIDED WITH WIND GOVERNOR THAT PERFORMS IGNITION CONTROL
First Claim
1. An engine-powered work tool comprising:
- an air-cooled engine including a crank shaft configured to rotate and a cooling fan fixed to the crank shaft and configured to rotate together with the crank shaft to generate cooling air;
an ignition system for igniting the engine;
an output controller configured to control an output of the engine, the output controller including a throttle valve shaft defining an axis and configured to make an angular rotation about the axis, the output of the engine being controlled based on the angular rotation of the throttle valve shaft;
a wind governor connected to the throttle valve shaft and including a governor plate configured to move upon receipt of the cooling air thereon, the wind governor being configured to control the angular rotation of the throttle valve shaft based on an amount of the cooling air received by the governor plate;
a rotation speed detector configured to detect a rotation speed of the crank shaft; and
an ignition control unit configured to control the ignition system based on the rotation speed of the crank shaft detected by the rotation speed detector to reduce the output of the engine when the rotation speed detector determines that the governor plate exceeds a predetermined position.
2 Assignments
0 Petitions
Accused Products
Abstract
An engine-powered work tool includes an engine having a crank shaft, an ignition system, an output controller having a throttle valve shaft for controlling output of the engine, a wind governor connected to the throttle valve shaft, a rotation speed detector and an ignition control unit. The wind governor includes a governor plate movable upon receipt of cooling air generated by a cooling fan to control an angular rotation of the throttle valve shaft. The rotation speed detector detects a rotation speed of the crank shaft. The ignition control unit controls the ignition system based on the rotation speed of the crank shaft detected by the rotation speed detector to reduce the output of the engine when the rotation speed detector determines that the governor plate exceeds a predetermined position.
15 Citations
10 Claims
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1. An engine-powered work tool comprising:
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an air-cooled engine including a crank shaft configured to rotate and a cooling fan fixed to the crank shaft and configured to rotate together with the crank shaft to generate cooling air; an ignition system for igniting the engine; an output controller configured to control an output of the engine, the output controller including a throttle valve shaft defining an axis and configured to make an angular rotation about the axis, the output of the engine being controlled based on the angular rotation of the throttle valve shaft; a wind governor connected to the throttle valve shaft and including a governor plate configured to move upon receipt of the cooling air thereon, the wind governor being configured to control the angular rotation of the throttle valve shaft based on an amount of the cooling air received by the governor plate; a rotation speed detector configured to detect a rotation speed of the crank shaft; and an ignition control unit configured to control the ignition system based on the rotation speed of the crank shaft detected by the rotation speed detector to reduce the output of the engine when the rotation speed detector determines that the governor plate exceeds a predetermined position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification