# US 2004/0069271 A1 · Watercraft propulsion system and control method of the system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2004/0069271 A1 - Document ID: US20040069271A1 - Status: Published application - Kind: A1 - Application number: 10/619,333 - Filed: 2003-07-14 - Published: 2004-04-15 - Earliest claimed: 2002-07-12 - Assignees: Yamaha Marine Kabushiki Kaisha - Inventors: Isao Kanno; Masahiko Kato; Goichi Katayama - Web page: https://patentgrep.com/patent/US20040069271A1 ## CPC - F02D 11/107: {Safety-related aspects} - F02B 61/045: {for marine engines} - F02D 9/1065: {Mechanical control linkage between an actuator and the flap, e.g. including levers, gears, springs, clutches, limit stops of the like} - F02D 35/0007: {using electrical feedback (F02D35/0015 takes precedence)} - F02D 41/221: {relating to the failure of actuators or electrically driven elements} - F02D 9/1095: {Rotating on a common axis, e.g. having a common shaft} - F02D 2009/0277: {Fail-safe mechanisms, e.g. with limp-home feature, to close throttle if actuator fails, or if control cable sticks or breaks} - F02D 2009/0281: {with means for detecting malfunction of one throttle and actuating only the correctly working throttle} - F02M 69/10: peculiar to scavenged two-stroke engines, e.g. injecting into crankcase-pump chamber - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF ## Abstract A propulsion system for a watercraft includes an engine. An air intake device delivers air to a combustion chamber. A throttle valve regulates an amount of the air. A control device sets the throttle valve to a desired position. A remote controller provides the control device with the desired position. The engine can include an auxiliary intake device that delivers supplemental air to the combustion chamber. A control valve normally shuts the supplemental air from the combustion chamber. The control device determines whether an abnormal condition occurs in setting the throttle valve to the desired position. The control device determines whether the amount of the air is insufficient. The control device controls the control valve to allow the supplemental air to move to the combustion chamber when the control device determines that the abnormal condition occurs and the amount of the air is insufficient. ## Claims ### Claim 1 A propulsion system for a watercraft comprising an internal combustion engine that defines a combustion chamber, an intake device that delivers air to the combustion chamber, a throttle valve that regulates an amount of the air, a control device that sets the throttle valve to a desired position, an operating unit that provides the control device with the desired position, and means for delivering at least a minimum amount of air that maintains an operation of the engine to the combustion chamber when an abnormal condition occurs in setting the throttle valve to the desired position. ### Claim 2 (depends on 1) The propulsion system as set forth in claim 1 additionally comprising a valve position sensor configured to sense the actual position of the throttle valve, the control device being configured to determine whether the abnormal condition occurs based upon an actual position sensed by the valve position sensor and the desired position provided by the operating unit, the control device being configured to control the control valve to allow the secondary air to move to the combustion chamber when the control device determines that the abnormal condition occurs. ### Claim 3 (depends on 2) The propulsion system as set forth in claim 2, wherein the control device is configured to determine that the abnormal condition occurs when a difference between the actual position of the throttle valve and the desired position is equal to or greater than a preset threshold value. ### Claim 4 (depends on 1) The propulsion system as set forth in claim 1, wherein the means for delivering at least a minimum amount of air is a mechanism that automatically moves the throttle valve to a preset position. ### Claim 5 (depends on 1) The propulsion system as set forth in claim 1 additionally comprising an outboard motor that has a propulsion device, the engine is incorporated in the outboard motor and powers the propulsion device. ### Claim 6 A propulsion system for a watercraft comprising an internal combustion engine that defines a combustion chamber, a first intake device configured to deliver primary air to the combustion chamber, a first valve configured to regulate an amount of the primary air, a control device configured to set the first valve to a desired position, an operating unit configured to provide the control device with the desired position, a second intake device being configured to deliver secondary air to the combustion chamber, and a second valve configured to control a flow of secondary air to combustion chamber, the control device being configured to determine whether an abnormal condition occurs in setting the first valve to the desired position, the control device being configured to determine whether the amount of the first air is insufficient, the control device being configured to control the second valve to allow the secondary air to move to the combustion chamber when the control device determines that the abnormal condition occurs and the amount of the first air is insufficient. ### Claim 7 (depends on 6) The propulsion system as set forth in claim 6 additionally comprising a valve position sensor configured to sense the actual position of the first valve, the control device being configured to determine whether the abnormal condition occurs based upon an actual position sensed by the valve position sensor and the desired position provided by the operating unit. ### Claim 8 (depends on 7) The propulsion system as set forth in claim 7, wherein the control device is configured to determine that the abnormal condition occurs when a difference between the actual position of the first valve and the desired position is equal to or greater than a preset threshold value. ### Claim 9 (depends on 7) The propulsion system as set forth in claim 7, wherein the control device is configured to determine that the abnormal state occurs when the actual position of the first valve does not follow the desired position provided by the operating unit. ### Claim 10 (depends on 6) The propulsion system as set forth in claim 6 additionally comprising a first valve actuator configured to actuate the first valve toward the desired position, the control device being configured to control the first valve actuator based upon the desired position provided by the operating unit. ### Claim 11 (depends on 6) The propulsion system as set forth in claim 6 additionally comprising a second valve actuator configured to actuate the second valve between a shutting position that does not allow the second air to the combustion chamber and a releasing position that allows the second air to the combustion chamber, the control device being configured to control the second valve actuator. ### Claim 12 (depends on 6) The propulsion system as set forth in claim 6, wherein the control device is configured to control the engine to increase an engine speed when the control device determines that the abnormal state occurs and the amount of the primary air is insufficient. ### Claim 13 (depends on 6) The propulsion system as set forth in claim 6 additionally comprising a firing system configured to fire an air/fuel charge in the combustion chamber, the control device being configured to retard a firing timing of the firing system to decrease the engine speed during an abnormal state of the first valve. ### Claim 14 A propulsion system for a watercraft comprising an internal combustion engine that defines a combustion chamber, an intake device configured to deliver air to the combustion chamber, a throttle valve configured to regulate an amount of the air, a control device configured to set the throttle valve to a desired position, an operating unit configured to provide the control device with the desired position, the control device being configured to determine whether an abnormal state occurs in setting the throttle valve to the desired position, the control device being configured to determine whether the watercraft is berthing, the control device also being configured to decrease an engine speed of the engine when the control device determines that the abnormal state occurs and the watercraft is berthing. ### Claim 15 (depends on 14) The propulsion system as set forth in claim 14 additionally comprising means for detecting that the watercraft is berthing, the control device determining that the watercraft is berthing by an output from the means for detecting the watercraft is berthing. ### Claim 16 A propulsion system for a watercraft comprising an outboard drive, the outboard drive having a propulsion device that propels the watercraft, the propulsion device being selectively operable at least in a forward or reverse mode, an internal combustion engine that powers the propulsion device, the engine defining a combustion chamber, an intake device configured to deliver air to the combustion chamber, a throttle valve configured to regulate an amount of the air, a control device configured to set the propulsion device in the forward or reverse position and to set the throttle valve to a desired position, and a operating unit configured to provide the control device with the forward or reverse mode and the desired position, the control device being configured to determine whether an abnormal state occurs in setting the throttle valve to the desired position, the control device also being configured to determine whether the operating unit provides the control device with the reverse mode, the control device further being configured to decrease an engine speed of the engine when the control device determines that the abnormal state occurs and that the operating unit provides the control device with the reverse mode. ### Claim 17 (depends on 16) The propulsion system as set forth in claim 16 additionally comprising a valve position sensor configured to sense the actual position of the throttle valve, the control device being configured to determine whether the abnormal state occurs based upon an actual position sensed by the valve position sensor and the desired position provided by the operating unit. ### Claim 18 (depends on 16) The propulsion system as set forth in claim 16 additionally comprising a changeover mechanism configured to move the propulsion device between the forward and reverse modes. ### Claim 19 A propulsion system for a watercraft comprising an outboard drive, the outboard drive having a propulsion device that propels the watercraft, the propulsion device being selectively operable at least in a forward or reverse mode, an internal combustion engine that powers the propulsion device, the engine defining a combustion chamber, an intake device configured to deliver air to the combustion chamber, a throttle valve being configured to regulate an amount of the air, a throttle valve capable to be set to a desired position, an operating unit being configured to operate the propulsion device between the forward and reverse modes, a connecting device being configured to selectively connect the throttle valve and the operating device, and a control device configured to determine whether an abnormal state occurs in setting the throttle valve to the desired position, the control device being configured to activate the connecting device to connect the throttle valve and the operating unit when the control device determines that the abnormal state occurs. ### Claim 20 (depends on 19) The propulsion system as set forth in claim 19, wherein the throttle valve is configured to regulate the amount of the air to decrease when the connecting device is activated. ### Claim 21 A propulsion system for a watercraft comprising an internal combustion engine that defines a combustion chamber, an intake device configured to deliver air to the combustion chamber, a throttle valve configured to regulate an amount of the air, a control device configured to set the throttle valve to a desired position, an operating unit configured to provide the control device with the desired position, a communication device through which the operating unit can communicate with the control device, and an auxiliary operating unit configured to set the throttle valve to a desired position when an abnormal state occurs at the operating unit or in the communication device. ### Claim 22 (depends on 21) The propulsion system as set forth in claim 21, wherein the communication device has an open node, the auxiliary operating unit has an output port detachably connectable to the open node. ### Claim 23 (depends on 21) The propulsion system as set forth in claim 21, wherein the operating unit is configured to provide the desired position to the control device by a data packet, the control device being configured to determine that the abnormal state occurs at the operating unit or in the communication device if the control device does not receive the data packet within a preset time. ### Claim 24 (depends on 21) The propulsion system as set forth in claim 21 additionally comprising an alarming device, the control device being configured to control the alarming device to alarm when the abnormal state occurs. ### Claim 25 A propulsion system for a watercraft comprising an internal combustion engine that defines a combustion chamber, an intake device configured to deliver air to the combustion chamber, a throttle valve configured to regulate an amount of the air, a control device configured to set the throttle valve to a desired position, an operating unit configured to provide the control device with the desired position, a communication device through which the operating unit can communicate with the control device, and an alarming device configured to emit an alarm when an abnormal state occurs in the communication device. ### Claim 26 A control method for controlling a watercraft propulsion system that has an engine, comprising regulating an amount of air to the engine with a regulating device, setting the regulating device to a desired regulating position, providing the desired regulating position to an operating unit, determining whether an abnormal state occurs in setting the regulating device to the desired regulating position, and delivering at least a minimum amount of air to the engine so as to maintain an operation of the engine when the occurrence of the abnormal state is determined. ### Claim 27 (depends on 26) The control method as set forth in claim 26 additionally comprising sensing an actual regulating position of the regulating device, and comparing the actual regulating position with the desired regulating position. ### Claim 28 (depends on 26) The control method as set forth in claim 26, wherein the regulating device is a throttle valve. ### Claim 29 A control method for controlling a watercraft propulsion system that has an engine, comprising regulating an amount of air to the engine with a regulating valve, setting the regulating valve to a desired regulating position, providing the desired regulating position to an operating unit, determining whether an abnormal state occurs in setting the regulating valve to the desired regulating position, determining whether the amount of the air is insufficient, and delivering a supplementary amount of air to the engine when the occurrence of the abnormal state is determined and the insufficient condition of the air is determined. ### Claim 30 (depends on 29) The control method as set forth in claim 29 additionally comprising sensing an actual regulating position of the regulating valve, and comparing the actual regulating position with the desired regulating position. ### Claim 31 (depends on 29) The control method as set forth in claim 29 additionally comprising actuating a control valve of an auxiliary air delivery device to deliver the supplementary amount of the air. ### Claim 32 (depends on 29) The control method as set forth in claim 29 additionally comprising determining the amount of the air is insufficient when the regulating valve is placed adjacent to a closed position of an air delivery device more than an open position of the air delivery device. ### Claim 33 (depends on 29) The control method as set forth in claim 29 additionally comprising increasing an engine speed of the engine when the occurrence of the abnormal state is determined and the insufficient condition of the air is determined. ### Claim 34 A control method for controlling a watercraft propulsion system that has an engine, comprising regulating an amount of air to the engine by a regulating valve, setting the regulating valve to a desired regulating position, providing the desired regulating position by an operating unit, determining whether an abnormal state occurs in setting the regulating valve to the desired regulating position, determining whether the watercraft is berthing, and decreasing an engine speed of the engine when the occurrence of the abnormal state is determined and the berthing condition of the watercraft is determined. ### Claim 35 A control method for controlling a watercraft propulsion system that has an engine and a propulsion device, comprising regulating an amount of air to the engine with a regulating valve, setting the regulating valve to a desired regulating position, providing the desired regulating position to an operating unit, providing a forward or reverse mode of the propulsion device to the operating unit, determining whether an abnormal state occurs in setting the regulating valve to the desired regulating position, determining whether the reverse mode is provided to the operating unit, and decreasing an engine speed of the engine when the occurrence of the abnormal state is determined and the provision of the reverse mode to the operating unit is determined. ### Claim 36 (depends on 35) The control method as set forth in claim 35 additionally comprising sensing an actual regulating position of the regulating valve, and comparing the actual regulating position with the desired regulating position. ### Claim 37 A control method for controlling a watercraft propulsion system that has an engine, comprising regulating an amount of air to the engine with a regulating device, setting the regulating device to a desired regulating position, providing the desired regulating position to an operating unit, determining whether the desired regulating position is normally provided to the regulating device by the operating unit, and triggering an alarm when the determination is negative.