Engine speed control system for outboard motor

• US 7,077,713 B2
• Filed: 09/25/2003
• Issued: 07/18/2006
• Est. Priority Date: 10/02/2002
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Takada, Hideaki, Masubuchi, Yoshinori, Watabe, Hiroshi
• Primary Examiner(s): BASINGER, SHERMAN D
• Application Number:
  US10/669,716
• Publication Number:
  US 20040065300A1
• Time in Patent Office: 1,027 Days
• Field of Search: 440/1, 440/84, 440/87
• US Class Current: 440/1
• CPC Class Codes: A61K 2300/00 Mixtures or combinations of active ingredients, wherein at least one active ingredient is fully defined in groups A61K31/00 - A61K41/00
• CPC Class Codes: A61K 31/7088 Compounds having three or more nucleosides or nucleotides
• CPC Class Codes: A61K 38/18 Growth factors; Growth regulators
• CPC Class Codes: A61K 38/1858 Platelet-derived growth factor [PDGF]
• CPC Class Codes: A61K 38/1866 Vascular endothelial growth factor [VEGF]
• CPC Class Codes: F02B 61/045 for marine engines
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: 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
• CPC Class Codes: F02D 31/006 for maximum speed control
• CPC Class Codes: G01N 33/5058 Neurological cells
• CPC Class Codes: G01N 33/5073 Stem cells

Abstract

In an engine speed control system for an outboard motor having a throttle valve that regulates air to be sucked and an actuator connected to the throttle valve to move it in an opening direction or in a closing direction, the actuator is driven to move the throttle valve in the closing direction such that the engine speed drops, if it is discriminated that a detected engine speed exceeds a predetermined speed (set to a speed at which the engine can assumably continue to run until the boat has returned to port), when a trouble has occurred in the engine. Thus, the system can lower the engine speed so as to allow the boat to return to port, without causing the engine to vibrate, when a trouble has occurred in the engine.

Claims

1. A system for controlling a speed of an internal combustion engine installed in an outboard motor mounted on a boat and having a propeller powered by the engine to propel the boat, the engine having a throttle valve that regulates air to be sucked, comprising:

an actuator connected to the throttle valve to move it in an opening direction or in a closing direction;

engine speed detecting means for detecting the speed of the engine;

engine trouble detecting means for detecting a trouble occurred in the engine;

engine speed discriminating means for discriminating whether the detected engine speed exceeds a predetermined speed which is larger than an engine idle speed when it is detected that the trouble has occurred in the engine; and

actuator driving means for driving the actuator to move the throttle valve in the closing direction such that the engine speed drops, when it is discriminated that the detected engine speed exceeds the predetermined speed, wherein

the actuator driving means drives the actuator to move the throttle valve in the closing direction by an amount repeatedly such that the engine speed is gradually lowered to the predetermined speed.

2. A system according to claim 1, wherein the trouble includes at least one of engine overheating, shortage of engine oil and excessive engine revving.

3. A system according to claim 1, further including:

alerting means for alerting an operator to occurrence of the trouble.

4. A system according to claim 1, wherein the predetermined speed is a speed at which the engine can assumably continue to run until the boat has returned to port.

5. A method of controlling speed of an internal combustion engine installed in an outboard motor mounted on a boat and having a propeller powered by the engine to propel the boat, the engine having a throttle valve that regulates air to be sucked and an actuator connected to the throttle valve to move it in an opening direction or in a closing direction, comprising the steps of:

detecting the speed of the engine;

detecting a trouble occurred in the engine;

discriminating whether the detected engine speed exceeds a predetermined speed which is larger than an engine idle speed when it is detected that the trouble has occurred in the engine; and

driving the actuator to move the throttle valve in the closing direction such that the engine speed drops, when it is discriminated that the detected engine speed exceeds the predetermined speed, wherein

the step of actuator driving drives the actuator to move the throttle valve in the closing direction by an amount repeatedly such that the engine speed is gradually lowered to the predetermined speed.

6. A method according to claim 5, wherein the trouble includes at least one of engine overheating, shortage of engine oil and excessive engine revving.

7. A method according to claim 5, further including the step of:

alerting an operator to occurrence of the trouble.

8. A method according to claim 5, wherein the predetermined speed is a speed at which the engine can assumably continue to run until the boat has returned to port.

9. A computer program embodied on a computer-readable medium for controlling speed of an internal combustion engine installed in an outboard motor mounted on a boat and having a propeller powered by the engine to propel the boat, the engine having a throttle valve that regulates air to be sucked and an actuator connected to the throttle valve to move it in an opening direction or in a closing direction, comprising the steps of:

detecting the speed of the engine;

detecting a trouble occurred in the engine;

discriminating whether the detected engine speed exceeds a predetermined speed which is larger than an engine idle speed when it is detected that the trouble has occurred in the engine; and

driving the actuator to move the throttle valve in the closing direction by an amount repeatedly such that the engine speed is gradually lowered to the predetermined speed, when it is discriminated that the detected engine speed exceeds the predetermined speed.