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US 6,648,706 B2Granted
Control system for marine engine
AssigneeYamaha Marine Kabushiki Kaisha
InventorIsao Kanno
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AssigneeYamaha Marine Kabushiki Kaisha
InventorIsao Kanno
Estimating the term…
A personal watercraft includes a hull and a jet propulsion unit that propels the hull. An engine powers the jet propulsion unit. The engine includes an air intake system to introduce air to a combustion chamber. The intake system includes a throttle valve to regulate an amount of the air. The throttle valve is moveable generally between a closed position and an open position. A fuel injection system is arranged to spray fuel for combustion in the combustion chamber. The engine also includes an intake pressure sensor, a throttle valve position sensor and an engine speed sensor. A control device is provided to control an amount of the fuel using either a D-j control mode or an α-N control mode. The D-j control mode is based upon a signal from the intake pressure sensor and a signal from the engine speed sensor. The α-N control mode is based upon a signal from a throttle valve position sensor and the signal from the engine speed sensor. The control device uses the D-j control mode either when the throttle valve is relatively in a low opening degree range or when an engine speed is relatively in a low speed range, and uses the α-N control mode either when the throttle valve is relatively in a high opening degree range or when the engine speed is relatively in a high speed range. Additionally, the control device is configured to detect the malfunction of the throttle valve position sensor and the pressure sensor. If the throttle valve position sensor malfunctions, the control device uses only the D-j control mode. If the pressure sensor malfunctions, the control device uses only the α-N control mode.
A planing-type watercraft comprising a hull, a propulsion device arranged to propel the hull, an internal combustion engine driving the propulsion device, the engine comprising an engine body, at least one moveable member moveable relative to the engine body, the engine body and the moveable member together defining at least one combustion chamber, an air intake system configured to guide air to the combustion chamber, the intake system including a throttle valve, the throttle valve moveable generally between a closed position and an open position, a fuel injection system configured to inject fuel for combustion in the combustion chamber, an intake pressure sensor, a throttle position sensor, an engine speed sensor, and a control device configured to control an amount of the fuel using either a first control mode or a second control mode, the first control mode being based upon a signal from the intake pressure sensor and a signal from the engine speed sensor, the second control mode being based upon a signal from the throttle position sensor and the signal from the engine speed sensor, the control device using the first control mode when either an opening of the throttle valve is relatively small or when an engine speed is relatively low, the control device using the second control mode when either the opening of the throttle valve is relatively large and when the engine speed is relatively high, the controller being further configured to use only the first control mode for all engine speeds if the throttle position sensor malfunctions and to use only the second control mode for all engine speeds if the intake pressure sensor malfunctions.
A watercraft comprising a hull, an engine supported by the hull, the engine comprising an engine body, a fuel supply system connected to the engine and configured to supply fuel for combustion in the engine body, a first sensor configured to detect a first engine operation parameter and a second sensor configured to detect a second engine operation parameter, and a controller configured to control at least the fuel supply system, the controller being configured to control the fuel supply system according to a first mode in a first engine speed range and to control the fuel supply system according to a second mode in a second engine speed range, the controller being further configured to control the fuel supply system according to a malfunction mode in which the first mode is used to control the fuel supply system for the second engine speed range if the second sensor malfunctions, and to use the second mode to control the fuel supply system for the first engine speed range if the first sensor malfunctions.
A watercraft comprising a hull, an engine supported by the hull, the engine comprising an engine body, a fuel supply system connected to the engine and configured to supply fuel for combustion in the engine body, a first sensor configured to detect a first engine operation parameter and a second sensor configured to detect a second engine operation parameter, and a controller configured to control at least the fuel supply system, the controller being configured to control the fuel supply system according to a first mode in a first engine speed range and to control the fuel supply system according to a second mode in a second engine speed range, the controller comprising malfunction mode means for controlling the fuel supply system according to a malfunction mode in which the first mode is used to control the fuel supply system for the second engine speed range if the second sensor malfunctions, and to use the second mode to control the fuel supply system for the first engine speed range if the first sensor malfunctions.
A method for controlling an engine for a watercraft, the method comprising detecting an engine speed, determining if the engine speed is in a first engine speed range or a second engine speed range which is higher than the first speed range, controlling fuel supply to the engine according to a first mode based on output from a first sensor when the engine speed is in the first range, controlling fuel supply to the engine according to a second mode based on output from a second sensor when the engine speed is in the second range, detecting a malfunction of the first and second sensors, controlling fuel supply according to the first mode in the second speed range when the second sensor malfunctions, and controlling fuel supply according to the second mode in the first engine speed range when the first sensor malfunctions.
Dependencies are inferred from the claim text.