Two-cycle engine with exhaust temperature-controlled ignition timing
AssigneeArctic Cat Inc.
InventorGreg Spaulding
Life of this patent
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Abstract
A two-cycle internal combustion engine has an ignition timing that varies with engine speed. A plurality of ignition patterns (the relationship between ignition timing and engine speed) are used. The engine exhaust gas temperature is sensed and is used to determine the particular ignition pattern used at a particular time.
Claims21
A two-cycle engine, comprising;
- a cylinder;
- a piston movable in the cylinder, for compressing a fuel-air mixture to be ignited in the cylinder, with exhaust gas from combustion of the fuel-air mixture being expelled from the cylinder;
- an ignition source in the cylinder;
- a controller for activating the ignition source at a particular point during the movement of the piston, the controller containing a plurality of ignition patterns, each of said patterns reflecting desired ignition points that vary as a function of the operation speed of the engine;
- and
- a sensor for sensing a temperature of exhaust gas from the cylinder and for providing a signal to the controller indicative of the temperature of the exhaust gas;
- wherein the controller selects an ignition pattern based upon the sensed exhaust gas temperature.
A method of operating a two-cycle engine, comprising:
- moving a piston in a cylinder to compress a fuel-air mixture in the cylinder;
- activating an ignition source in the cylinder during the movement of the piston;
- expelling exhaust gas from combustion of the fuel-air mixture from the cylinder;
- sensing a temperature of the exhaust gas expelled from the cylinder;
- and
- selecting an ignition pattern from a plurality of ignition patterns based on the sensed exhaust temperature, each of said ignition patterns reflecting desired ignition points that vary as a function of the operation speed of the engine;
- and
- controlling the activation of the ignition source according to the selected ignition pattern.
A method of operating a two-cycle engine having a piston movable within a cylinder, an ignition source to ignite fuel in the cylinder, an exhaust system for carrying exhaust gas expelled from the cylinder, and a controller for controlling activation of the ignition source, the method comprising:
- storing a plurality of ignition patterns in the controller, each of said ignition patterns reflecting desired ignition points that vary as a function of the operation speed of the engine at a particular range of exhaust gas temperatures;
- moving the piston in the cylinder to compress a fuel-air mixture in the cylinder;
- activating the ignition source in the cylinder during the compression movement of the piston;
- expelling exhaust gas from the cylinder;
- sensing a temperature of the exhaust gas expelled from the cylinder;
- and
- selecting a desired ignition pattern based on the sensed exhaust gas temperature;
- and
- controlling the activation of the ignition source according to the selected ignition pattern.
Dependencies are inferred from the claim text.