Patent Application
20120282828
This application claims priority to Japanese Patent Application No. 2011-103056 filed on May 2, 2011, the entirety of which is hereby incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a marine propulsion device.
2. Description of the Related Art
In marine propulsion devices such as the outboard motors, a drive shaft and a propeller are coupled through a rearward travel gear when a shift lever is shifted to a rearward travel position during high speed navigation. However, when the propeller is coupled to the rearward travel gear, the propeller can be rotated by a water stream passing through the propeller in a forward travel direction. Accordingly, the engine is reversely rotated. Marine propulsion devices are normally configured to discharge exhaust gas from the engine into the water through an exhaust path. Therefore, reverse rotation of the engine causes a phenomenon of inhaling water into the engine through the exhaust path. Such water intrusion into the engine may damage or break the engine.
Japan Laid-open Patent Application Publication No. JP-A-2003-120397 describes a device configured to count an angle signal of a crankshaft and detect reverse rotation of the crankshaft in accordance with the counted values. Further, the device is configured to stop ignition and fuel supply when detecting reverse rotation of the crankshaft. Thus, water intrusion into the engine is prevented by stopping the engine.
Further, Japan Laid-open Patent Application Publication No. JP-A-2008-274970 describes a device configured to detect reverse rotation of a crankshaft by detecting a crankshaft rotational angle and a cam shaft rotational angle. The device is configured to forcibly shift a forward/rearward travel switching gear to a neutral position when detecting reverse rotation of the crankshaft. Accordingly, water intrusion into the engine is prevented.
According to the device of Japan Laid-open Patent Application Publication No. JP-A-2003-120397, the propeller is rotated by the water stream even when ignition is stopped. Accordingly, reverse rotation of the crankshaft is continued. Therefore, prevention of water intrusion into the engine is relatively ineffective. According to the device of Japan Laid-open Patent Application Publication No. JP-A-2008-274970, on the other hand, the crankshaft may be continuously reversely rotated until the gear is completely shifted to the neutral position. In addition, reverse rotation of the crankshaft may be continued due to an inertial force for a while even after the gear is completely shifted to the neutral position. Therefore, prevention of water intrusion into the engine is limited. In view of the above, both devices described in the above-identified publications can prevent a large amount of water intrusion into the engine but cannot completely prevent water intrusion into the engine. In other words, both devices cannot prevent a small amount of water intrusion into the engine. When a small amount of water intrudes into the engine, the engine may be damaged or broken due to its corrosion after the elapse of a long period of time, even if the engine is not be immediately damaged or broken.
In order to overcome the problems described above, preferred embodiments of the present invention provide a marine propulsion device that prevents damage and breakage of the engine due to water intrusion.
A marine propulsion device according to a preferred embodiment of the present invention includes an engine, a propeller, a drive shaft, an exhaust path, a water intrusion detecting portion, and a recording portion. The drive shaft is configured to transmit a driving force from the engine to the propeller. The exhaust path allows exhaust air from the engine to pass therethrough. The water intrusion detecting portion is configured to detect a water intrusion potential indicating a possibility of water intrusion into the engine through the exhaust path. The recording portion is configured to record a detection result of the water intrusion detecting portion.
A marine propulsion device according to another preferred embodiment of the present invention includes an engine, a propeller, a drive shaft, an exhaust path, a water intrusion detecting portion, and a notifying portion. The drive shaft is configured to transmit a driving force from the engine to the propeller. The exhaust path allows exhaust air from the engine to pass therethrough. The water intrusion detecting portion is configured to detect a state of being prone to water intrusion into the engine through the exhaust path, that is, a state having a tendency or likelihood of water intrusion. The notifying portion is configured to perform a notifying action in accordance with a detection result by the water intrusion detecting portion.
According to the marine propulsion device of a first preferred embodiment of the present invention, when the water intrusion detecting portion detects the water intrusion potential, the recording portion is configured to record the detection result. Therefore, water intrusion potential can be obtained by examining the record stored in the recording portion at the time of maintenance without disassembling the engine. Thus, repair and inspection can thereby be executed while the engine is in a normal condition, and breakage or damage of the engine can thereby be prevented.
According to the marine propulsion device of a second preferred embodiment of the present invention, when the water intrusion detecting portion detects the state of being prone to water intrusion, the notifying portion is configured to provide notification of the detection result. Therefore, an operator is alerted by the notification of the notifying portion, and can avoid a type of operation that might cause water intrusion. Thus, water intrusion into the engine can be prevented, and breakage or damage of the engine can thereby be prevented.
The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.
A marine propulsion device according to a preferred embodiment of the present invention will be hereinafter explained with reference to the attached drawings. In the present preferred embodiment, a marine propulsion device preferably is an outboard motor. However, the present invention can be applied to the other types of the marine propulsion devices such as an inboard/outboard motor.
The engine 5 is disposed within the top casing 2. The engine 5 includes a crankshaft 12. A drive shaft 11 is disposed within the bottom casing 3. The drive shaft 11 is disposed within the bottom casing 3 along a vertical (up-and-down) direction. The drive shaft 11 is coupled to the crankshaft 12 of the engine 5. Further, a propeller 13 is disposed in the lower portion of the bottom casing 3. The propeller 13 is disposed below the engine 5. A propeller shaft 14 is coupled to the propeller 13. The propeller shaft 14 is disposed along a longitudinal (front-to back) direction of the marine propulsion device 1. The propeller shaft 14 is coupled to the bottom end of the drive shaft 11 through a forward/rearward travel switching portion 15.
As illustrated in
In the marine propulsion device 1, a driving force generated by the engine 5 is configured to be transmitted to the propeller 13 through the drive shaft 11 and the propeller shaft 14. Accordingly, the propeller 13 is rotated in either the forward travel direction or the rearward travel direction. As a result, a propulsion force is generated to cause the vessel body including the marine propulsion device 1 to travel forwards or rearwards.
As illustrated in
The cylinder head 23 includes an intake port 31, an exhaust port 32, and a combustion chamber 33. The intake port 31 and the exhaust port 32 communicate with the combustion chamber 33. The intake port 31 is configured to be opened or closed by an intake valve 34. The exhaust port 32 is configured to be opened or closed by an exhaust valve 35. An intake manifold 36 is connected to the intake port 31. Further, a fuel injector 37 is attached to the intake manifold 36. The fuel injector 37 is configured to inject fuel to be supplied to the combustion chamber 33. A throttle valve 38 is disposed in the intake manifold 36. The opening degree of the throttle valve 38 is configured to be changed to regulate the amount of mixed air and gas to be supplied to the combustion chamber 33. On the other hand, an exhaust manifold 40 is connected to the exhaust port 32. An ignition device 39 is attached to the cylinder head 23. The ignition device 39 is inserted into the combustion chamber 33 to ignite the fuel therein.
The intake valve 34 is urged in a direction of closing the intake port 31 by an urging member such as a coil spring (not illustrated in the figures). The intake valve 34 is configured to be opened or closed by rotational driving of an intake cam shaft 41. On the other hand, the exhaust valve 35 is urged in a direction of closing the exhaust port 32 by an urging member such as a coil spring (not illustrated in the figures). The exhaust valve 35 is configured to be opened or closed by rotational driving of an exhaust cam shaft 42.
The operating unit 52 includes a throttle operating device 55, a shift operating device 56, and a start/stop operating device 57 for the engine 5. The throttle operating device 55 includes, for instance, a throttle operating member 55a such as a throttle lever. The throttle operating device 55 is configured to input an operating signal into the ECU 51 in response to an operation of the throttle operating member 55a in order to control an output of the engine 5. On the other hand, the shift operating device 56 includes, for instance, a shift operating member 56a such as a shift lever. The shift operating device 56 is configured to input an operating signal into the ECU 51 in response to an operation of the shift operating member 56a in order to switch the travel direction of the vessel body between the forward travel direction and the rearward travel direction. Specifically, the shift operating member 56a is allowed to be operated and set in one of the shifted positions of the forward travel position, the rearward travel position, and the neutral travel position. One of the unique operating signals corresponding to the shifted positions is configured to be inputted into the ECU 51. The start/stop operating device 57 for the engine 5 is a key switch, for instance, and is configured to input an operating signal into the ECU 51 in order to start or stop the engine 5.
The ECU 51 includes a recording portion 71, a calculating portion 72, and an externally outputting portion 73. The recording portion 71 is a recording device configured to write and read electronic data. The recording portion 71 stores a control program to cope with preliminarily defined operating states. The calculating portion 72 is configured to determine the current operating state based on signals from the various sensors 61 to 69 and the operating unit 52 and control actions of the ignition device 39, the fuel injector 37, and the throttle valve 38 based on the control program. Further, the ECU 51 is configured to control the shift actuator 54 based on an operating signal from the shift operating device 56. For example, the shift actuator 54 includes a driving unit such as a motor. The shift actuator 54 is configured to be controlled by the ECU 51 and is thereby configured to move the dog clutch 19 to one of the forward travel position, the rearward travel position, and the neutral travel position.
The display unit 53 is configured to display a variety of vessel-body related information detected by the various sensors 61 to 69. For example, the display unit 53 is configured to display status information of the engine 5 such as the engine speed or the engine temperature. Further, the display unit 53 is configured to display an estimated speed of the vessel body calculated by the ECU 51. For example, the recording portion 71 stores a map representing a relationship among the engine speed, the intake pressure, and the vessel body speed. The aforementioned estimated speed is calculated based on the map.
The detection signals and the operating signals inputted into ECU 51 from the operating unit 52 and various sensors 61 to 69 are stored in the recording portion 71 as operational data. The externally outputting portion 73 is an interface to execute electronic data communication with external devices. The externally outputting portion 73 is configured to output the operational data stored in the recording portion 71 to the external device. As represented in
The calculating portion 72 of the ECU 51 functions as a water intrusion detecting portion according to a preferred embodiment of the present invention, which is configured to detect water intrusion potential. Water intrusion potential herein indicates the potential of water intrusion into the engine 5 through the exhaust path 20 illustrated in
The crank angle sensor 61 preferably is a magnetic sensor configured to detect passage of a plurality of protrusions 120 of the crankshaft 12 as illustrated in
The cam angle sensor 62 preferably is a magnetic sensor configured to detect passage of a plurality of protrusions 420 provided on the exhaust camshaft 42. In
As described above, the crankshaft 12 and the exhaust camshaft 42 are configured to be rotated in conjunction with each other. In other words, when the crankshaft 12 is rotated in a forward direction (i.e., a normal rotational direction), the first region A1 and the third region A3 appear in synchronization with each other at the same timing. In the case of the time chart of
When rotation of the crankshaft 12 is rotated in a reverse direction (i.e., an opposite direction to the normal rotational direction), by contrast, the timing of detecting the third region A3 is different from that in the normal rotation of the crankshaft 12. Accordingly, the detection pattern of detecting the first regions A1 and the third regions A3 in reverse rotation is different from that in the normal rotation. The calculating portion 72 is configured to determine that the crankshaft 12 is reversely rotated when the first regions A1 and the third regions A3 are detected in a different detection pattern from that in the normal rotation of the crankshaft 12.
When reverse rotation of the crankshaft 12 is detected, the calculating portion 72 is configured to determine whether or not the other predetermined conditions for water intrusion potential (see Steps S1 to S3 in
In Step S1, it is determined whether or not a period of time t1 or greater has elapsed after starting of the engine 5. In other words, it is determined whether or not reverse rotation of the crankshaft 12 is detected except when the engine 5 fails to be started. Starting of the engine 5 may be determined based on a starter relay signal or a variation in battery voltage for driving a starter. Alternatively, starting of the engine 5 may be determined based on an engine starting signal configured to be outputted when an engine starter key is turned. Yet alternatively, starting of the engine 5 may be determined based on whether or not the engine speed exceeds a predetermined threshold. The processing proceeds to Step S2 when the period of time t1 or greater is elapsed after starting of the engine 5. In other words, the processing proceeds to Step S2 when reverse rotation of the crankshaft 12 is detected except when the engine 5 fails to be started.
Next in Step S2, it is determined whether or not a period of time t2 or greater has elapsed after a command of stopping the engine 5 is generated. It other words, it is determined whether or not reverse rotation of the crankshaft 12 is detected except when the engine 5 is stopped. Specifically, it is determined whether or not the period of time t2 or greater has elapsed after an operating signal for stopping the engine 5 is generated by the start/stop operating device 57 of the engine 5 and is inputted into the ECU 51. The processing proceeds to Step S3 when the period of time t2 or greater has elapsed after the command of stopping the engine 5 is generated. In other words, the processing proceeds to Step S3 when reverse rotation of the crankshaft 12 is detected except when the engine 5 is stopped.
Next in Step S3, it is determined whether or not a period of time t3 or less has elapsed after the forward/rearward travel switching portion 15 is switched into the rearward travel state. In other words, it is determined whether or not reverse rotation of the crankshaft 12 is detected within a predetermined period of time from the point in time when the forward/rearward travel switching portion 15 is switched into the rearward travel state. Specifically, the point in time when the forward/rearward travel switching portion 15 is switched into the rearward travel state is determined based on a detection signal from the shifted position sensor 69. The processing proceeds to Step S4 when the period of time t3 or less has elapsed after the forward/rearward travel switching portion 15 is switched into the rearward travel state. In other words, the processing proceeds to Step S4 when reverse rotation of the crankshaft 12 is detected within a predetermined period of time from the point in time when the forward/rearward travel switching portion 15 is switched into the rearward travel state. The point in time when the forward/rearward travel switching portion 15 is switched into the rearward travel state may be determined based on an operating signal from the shift operating device 56. In other words, it may be determined that the forward/rearward travel switching portion 15 is switched into the rearward travel state when the shift operating member 56a is moved to the rearward travel position.
Next in Step S4, it is determined whether or not the engine 5 is stopped. More specifically, it is determined whether or not the engine 5 is stopped after reverse rotation of the crankshaft 12 is detected. For example, it is determined that the engine 5 is stopped when a detection signal from the crank angle sensor 61 is not detected for a predetermined period of time. The processing proceeds to Step S5 when it is determined that the engine 5 is stopped. In other words, the processing proceeds to Step S5 when the engine 5 is stopped after reverse rotation of the crankshaft 12 is detected.
Next in Step S5, a detection result of water intrusion potential is recorded in the recording portion 71. More specifically, the detection result of water intrusion potential is recorded in the recording portion 71 when reverse rotation of the crankshaft 12 is detected as a condition and the predetermined conditions regarding water intrusion potential represented in Steps S1 to S3 are all satisfied. Specifically, the detection result of water intrusion potential includes the number of reverse rotations of the crankshaft 12 (also hereinafter referred to as “reverse rotation number”), the number of times of detecting water intrusion potential as of the present point in time, the total operating time as of the present point in time, the vessel speed, and logging of the engine states.
The reverse rotation number of the crankshaft 12 is a value indicating the number of reverse rotations of the crankshaft 12 until the engine 5 is stopped from the point in time when reverse rotation of the crankshaft 12 is first detected. The reverse rotation number of the crankshaft 12 is configured to be calculated based on a detection signal from the crank angle sensor 61. In the present preferred embodiment, the number of times of detecting water intrusion potential as of the present in time is a value obtained by subtracting the number of times that the predetermined conditions of Steps S1 to S3 are not satisfied from the total number of times that reverse rotation of the crankshaft 12 is detected until the present point in time.
The total operating time as of the present point in time is set as the total operating time of the engine 5 elapsed until the engine 5 is stopped after water intrusion potential is detected since the first use of the engine 5. The vessel speed may be a vessel speed at a point in time when water intrusion potential is detected, alternatively a vessel speed at a point in time when reverse rotation is detected, and further alternatively a vessel speed at a point in time when a predetermined operation that might reverse rotation is executed. It is more preferable to record a vessel speed at a point in time when the forward/rearward travel switching portion 15 is switched into the rearward travel state. Specifically, the vessel speed to be recorded is an estimated vessel speed calculated by the calculating portion 72.
The logging of the engine states is a history of the engine information until the engine 5 is stopped from a point in time earlier by a predetermined period of time t4 than the point in time when water intrusion potential is first detected. The engine information indicates the states of the engine 5 and includes the information such as the throttle opening degree, the intake pressure, the engine speed, the switched state of the forward/rearward travel switching portion 15, and the shifted position of the shift operating member 56a. It should be noted that the engine information is configured to be recorded in the recording portion 71 at every predetermined period of time t5 (e.g., every ten seconds) during driving of the engine 5 regardless of detection of water intrusion potential. The recording portion 71 is configured to overwrite the past engine information to update the engine information with the latest information at every predetermined period of time. When water intrusion potential is detected, the recording portion 71 is configured to store the engine information in the aforementioned period of time without erasing the engine information by overwriting it. For example, at a point in time when water intrusion potential is detected, the recording portion 71 stores both the currently recorded engine information and the engine information until the engine 5 is stopped from the point in time when water intrusion is detected without overwriting the engine information as the logging of the engine states.
Next in Step S6, the display unit 53 displays an alarm message. The alarm message is of a type of alarm to notify an operator of the detection of water intrusion potential. Therefore, the display unit 53 is an example of a notifying portion according to a preferred embodiment of the present invention configured to notify detection of water intrusion potential. It should be noted that the display unit 53 may be configured to display different types of alarm messages in accordance with the reverse rotation number of the crankshaft 12. Alternatively, the display unit 53 may be configured to display different types of alarm messages in accordance with the number (i.e., frequency) of detections of reverse rotation of the crankshaft 12.
It should be noted that water intrusion potential is not detected when the predetermined conditions of water intrusion potential of Steps S1 to S3 are not satisfied. Further, the processing proceeds to Step S7 when it is determined that the engine 5 is not being stopped in Step S4.
In Step S7, it is determined whether or not the reverse rotation number of the crankshaft 12 exceeds a predetermined threshold N. More specifically, it is determined whether or not the reverse rotation number of the crankshaft 12 exceeds the predetermined threshold N after reverse rotation of the crankshaft 12 is detected. The processing proceeds to Step S8 when the reverse rotation number of the crankshaft 12 exceeds the predetermined threshold N after reverse rotation of the crankshaft 12 is detected. By contrast, the processing returns to Step S4 when the reverse rotation number of the crankshaft 12 does not exceed the predetermined threshold N.
In Step S8, detection results regarding water intrusion potential are recorded, including a detection result that the reverse rotation number exceeds an upper limit, instead of the detection result of the reverse rotation number of the crankshaft 12 to be recorded in Step S5. The detection results to be recorded in Step S8 further include the number of times of detecting water intrusion potential as of the present point in time, the total operating time as of the present point in time, the vessel speed, and logging of the engine states. However, these detection results regarding water intrusion potential are basically the same as those to be recorded in Step S5. Therefore, explanation thereof will be hereinafter omitted.
The marine propulsion device 1 according to the present preferred embodiment preferably includes the following features.
When water intrusion potential is detected, the detection result is recorded in the recording portion 71. In turn, the detection result regarding water intrusion potential recorded in the recording portion 71 is allowed to be outputted to an external device through the externally outputting portion 73. For example, the terminal device 80 (e.g., a personal computer) is connected to the externally outputting portion 73 through a communication device (wired communication, wireless communication, etc.). With reference to the detection results regarding water intrusion potential, a maintenance service staff can appropriately judge the engine states regarding water intrusion potential through the monitor screen of the terminal device 80. Therefore, repair and inspection can be executed while the engine 5 is in a normal condition. Breakage or damage of the engine 5 can thereby be prevented.
The predetermined conditions of water intrusion potential include, for example, detection of reverse rotation of the crankshaft 12. Therefore, it is possible to accurately detect a state with a higher water intrusion potential.
The predetermined conditions of water intrusion potential include that reverse rotation of the crankshaft 12 is detected except when the engine 5 fails to be started. When the engine 5 fails to be started, reverse rotation of the crankshaft 12 may be detected. In this case, however, chances are low that water intrusion actually occurs. Therefore, detection errors can be prevented without detecting water intrusion potential when reverse rotation is detected but the engine 5 fails to be started.
The predetermined conditions of water intrusion potential include that reverse rotation of the crankshaft 12 is detected except when the engine 5 is stopped. When the engine 5 is stopped, reverse rotation of the crankshaft 12 may be detected. In this case, however, chances are low that water intrusion actually occurs. Therefore, detection errors can be prevented without detecting water intrusion potential when reverse rotation is detected but when the engine 5 is stopped.
The predetermined conditions of water intrusion potential include that reverse rotation of the crankshaft 12 is detected within a predetermined period of time from the point in time when the forward/rearward travel switching portion 15 is switched into the rearward travel state. Chances are high that water intrusion actually occurs when reverse rotation is detected within a predetermined period of time from the point in time when the forward/rearward travel switching portion 15 is switched into the rearward travel state. Therefore, water intrusion potential can be accurately detected.
When the engine 5 is stopped after reverse rotation is detected, the detection result to be recorded is the reverse rotation number of the crankshaft 12 until the engine 5 is stopped from the point in time when reverse rotation is first detected. Accordingly, the engine states can be appropriately determined.
When the reverse rotation number of the crankshaft 12 exceeds a predetermined threshold, the detection result that the reverse rotation number of the crankshaft 12 exceeds the upper limit is recorded even if the engine 5 is not stopped after reverse rotation is detected. Reverse rotation of the crankshaft 12 may be continued when the forward/rearward travel switching portion 15 is in the rearward travel state, for instance, where the vessel body is forwardly moved by a plurality of marine propulsion devices or where the vessel body including the marine propulsion device 1 is forwardly moved while being tugged by another vessel. In this case, chances are high that water intrusion actually occurs even when the engine 5 is not stopped after reverse rotation is detected. Therefore, the engine states can be appropriately determined by causing the recording portion 71 to record the detection results regarding water intrusion potential, including the detection result that the reverse rotation number of the crankshaft 12 exceeds the upper limit, as described above.
Next, a second preferred embodiment of the present invention will be hereinafter explained. The structure of a marine propulsion device of the second preferred embodiment is similar to the marine propulsion device 1 of the first preferred embodiment. In the marine propulsion device of the second preferred embodiment, the calculating portion 72 of the ECU 51 is configured to detect a state of being prone to water intrusion into the engine 5 through the exhaust path 20.
First, in Step S11 it is determined whether or not the vessel speed is greater than or equal to a predetermined speed V1. An estimated vessel speed calculated by the calculating portion 72 is herein used as the vessel speed. The calculating portion 72 is configured to determine that the water intrusion prone state is produced when the vehicle speed is greater than or equal to the predetermined speed V1. Next, in Step S12 the calculating portion 72 causes the display unit 53 to display an alarm message. The alarm message is a type of message for providing notification of information of operations that cause an increase in a possibility of water intrusion. Specifically, the alarm message is a type of message for alerting an operator not to shift the shift operating member 56a to the rearward travel position. The alarm message is not displayed on the display unit 53 when the vessel speed is not greater than or equal to the predetermined speed V1 in Step S11.
In the marine propulsion device 1 according to the second preferred embodiment, the alarm message is configured to be displayed on the display unit 53 when the water intrusion prone state is detected. An operator is alerted by the alarm message of the display unit 53, and can avoid shifting the shift operating member 56a to the rearward travel position. Accordingly, water intrusion into the engine Scan be prevented, and breakage or damage of the engine 5 can be thereby prevented.
First and second preferred embodiments of the present invention have been described above. However, the present invention is not limited to the preferred embodiments described above, and a variety of changes can be herein made without departing from the scope of the present invention.
In the first preferred embodiment, the predetermined conditions of water intrusion potential preferably include detection of reverse rotation of the crankshaft 12 and the aforementioned respective conditions in Steps S1 to S3 (see
In the first preferred embodiment, the recording portion 71 is preferably configured to record an estimated vessel speed calculated by the calculating portion 72. When a vessel speed sensor configured to detect a vessel speed is connected to the ECU 51, the recording portion 71 may be configured to record a vessel speed detected by the vessel speed sensor. Alternatively, the recording portion 71 may be configured to record a vessel speed calculated based on positional information from a GPS (Global Positioning System). Further in the second preferred embodiment, either the vessel speed detected by the aforementioned vessel speed sensor or the vessel speed calculated based on the aforementioned positional information from a GPS may be used as the vessel speed in the determination condition of Step S11.
In the first preferred embodiment, the recording portion 71 is configured to record the engine information until the engine 5 is stopped from a point in time earlier by the period of time t4 than the point in time when water intrusion potential is first detected. Alternatively, the recording portion 71 may be configured to record the engine information until the engine 5 is stopped from a point in time earlier by the period of time t4 than the point in time when reverse rotation of the crankshaft 12 is first detected. Alternatively, the recording portion 71 may be configured to record the engine information within a predetermined period of time earlier than the point in time when water intrusion potential is first detected. Alternatively, the recording portion 71 may be configured to record the engine information from a point in time earlier by a predetermined period of time than the point in time when water intrusion potential is first detected to a point in time later by a predetermined period of time than the point in time when water intrusion potential is first detected. Yet alternatively, the recording portion 71 may be configured to record the engine information from a point in time earlier by a predetermined period of time than the point in time when reverse rotation of the crankshaft 12 is first detected to a point in time later by a predetermined period of time than the point in time when reverse rotation of the crankshaft 12 is first detected.
In the first preferred embodiment, the recording portion 71 is preferably configured to record the reverse rotation number of the crankshaft 12. Alternatively, the recording portion 71 may be configured to record the reverse rotation number of the flywheel 48 instead of the reverse rotation number of the crankshaft 12.
In the first preferred embodiment, the total operating time of the engine 5 from the first use of the engine 5 to the stop of the engine 5 is recorded as the time-related detection result regarding water intrusion potential. Alternatively, the total operating time of the engine 5 from the first use of the engine 5 to detection of reverse rotation of the crankshaft 12 may be recorded. The total operating time of the engine 5 is configured to be counted and recorded by a unit of a predetermined period of time (e.g., ten minutes). However, a period of time that the crankshaft 12 is reversely rotated may be shorter than the counting/recording unit. Therefore, the margin of error is small in the total operating time of the engine 5 to be recorded as the time-related detection result regarding water intrusion potential, even if either is selected from detection of reverse rotation of the crankshaft 12 and the point in time when the engine 5 is stopped as the final point in time for counting the total operating time of the engine 5. Yet alternatively, the recording portion 71 may be configured to record the date and time when reverse rotation of the crankshaft 12 is detected as the time-related detection result regarding water intrusion potential.
The notification by the notifying portion is not limited to the alarm message to be displayed on the display unit 53 as described in the aforementioned preferred embodiments. For example, the notification may be any suitable display such as an alarm lamp or sign. The notification by the notifying portion may be acoustically appealing such as a buzzer or a voice, instead of the visual notification. Further, detection of water intrusion potential may be notified using different types of notifications such as display of a message, lighting of a lamp, sounding a buzzer, and sounding a voice in accordance with the frequency of detections of reverse rotation of the crankshaft 12. For example, a checkup alarm for the engine 5 may be configured as the notification by using display of a message, lighting of a lamp or the like when frequency of detections of reverse rotation of the crankshaft 12 is less than a predetermined frequency N1. By contrast, a checkup alarm for the engine 5 may be configured as the notification by continuously sounding a buzzer or a voice when the frequency of detections of reverse rotation of the crankshaft 12 is greater than or equal to the predetermined frequency N1.
Similarly, detection of water intrusion potential may be notified using different types of notifications in accordance with the total reverse rotation number of the crankshaft 12. For example, a checkup alarm of the engine 5 may be configured as the notification using display of a message, lighting of a lamp or the like when the total reverse rotation number of the crankshaft 12 is less than a predetermined rotation number N2. By contrast, a checkup alarm for the engine 5 may be configured as the notification by continuously sounding a buzzer or a voice when the total reverse rotations number of the crankshaft 12 is greater than or equal to the predetermined rotation number N2.
The externally outputting portion 73 may be configured to output electronic data containing the aforementioned detection results of water intrusion potential to a recording medium such as a nonvolatile memory and not to the terminal device 80.
While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-103056 | May 2011 | JP | national |
