The present application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2006-140539, filed on May 19, 2006, the entire contents of which is expressly incorporated by reference herein.
1. Field of the Inventions
The present inventions generally relate to engine control systems, and more specifically, to a shift cutout control system to facilitate interception of the power transmission, i.e. shift cutout, in an internal combustion engine having ignition cutout control for deactivating certain cylinder(s).
2. Description of the Related Art
An outboard motor of a watercraft uses power transmitted from an internal combustion engine to drive a propeller. This power is controlled by shifting a control lever among a forward position (causing propeller rotation in forward direction), a neutral position, and a reverse position (causing propeller rotation in an opposite direction), which shifting actuates a dog clutch. In the case of hard deceleration during the high-speed operation of the engine, shift cutout cannot be performed by merely lowering the throttle or dropping the engine rpm. A shift cutout control is implemented in such situations to reduce the torque of the engine by suspending the ignition operation in certain cylinder(s).
One example of the conventional shift cutout control device, as shown in
The example shown in
The fixed bracket 51 has a first stopper 61 for blocking the movable bracket 54 from clockwise rotation, as in the
The fixed bracket 51 has a shift cutout switch 64, and the movable bracket 54 has a pressing part 65. The pressing part 65 closes the contact point of the shift cutout switch 64 when the movable bracket 54, resisting the force of the torsion spring 63, is rotated counterclockwise in
In conventional shift cutout control devices similar to that described above, the roller 55 is moved along the guide rail 53 by the shifting force exerted on the remote control cable when the control lever of the remote controller is rotated. The movement of the roller 55 results in corresponding movement of the connecting lever 58, which is joined to the roller 55. Then, the lever 60 joined to the connecting lever 58 makes a swinging motion to rotate the shift rod 59, which causes the shifting of the dog clutch. On the other hand, as the roller 55 is moved along the guide rail 53, the shifting force from the forward position to the neutral position (shifting force fF) or the shifting force from the reverse position to the neutral position (shifting force fR) imposes a given preset level of force (namely the shifting force necessary to shift back to neutral position from forward or reverse position). Then, the movable bracket 54 rotates counterclockwise to turn on the shift cutout switch by the pressing part 65. The turn-on signal of the shift cutout switch 64 is transferred to the ignition control circuit of the internal combustion engine 50. Receiving the turn-on signal, the ignition control circuit determines that the shift cutout switch 64 has sensed the occurrence of shifting force fF or fR exceeding the given level, and implements the ignition cutout in the internal combustion engine 50 to reduce its torque. The shift cutout operation is therefore facilitated in this manner.
In the case of shift cutout control systems of the conventional mechanical remote control devices described above, the shift cutout switch 64 is used to detect the conditions for initiating the shift cutout. Simply, the shift cutout switch 64 mechanically reads the shifting force transmitted to the remote control cable 57 through the rotating motion of the control lever. In such a system, the performance of the shift cutout control is dependent on the quality of the shift cutout switch 64, and the space for attaching the shift cutout switch 64 must be maintained on the internal combustion engine 50.
According to at least one of the embodiments disclosed herein, a shift cutout control system is provided to mitigate and/or eliminate the problems related to the conventional shift cutout control devices described above. In particular, embodiments of the shift cutout control system can intercept power transmission from an engine in the event of certain circumstances (hereinafter such interception of the power transmission will be referred to as “shift cutout”). For example, an object of the present inventions is to provide a compact shift cutout control system that utilizes an electronic remote control device to obtain highly reliable shift cutout performance. In addition, a shift cutout control method is provided to eliminate the need for a shift cutout switch, thus eliminating dependence on the quality of the shift cutout switch to provide desirable performance. Further, another object is to eliminate the need for maintaining a space in/around the engine for mounting the shift cutout switch. Furthermore, it is contemplated that in some embodiments, the shift cutout control system can be utilized with a watercraft for a watercraft propulsion unit.
In accordance with an embodiment, the shift cutout control system can include a shift mechanism, an electronic control unit, a remote controller, and an ignition control means. The shift mechanism can be operative to switch a rotation of a propeller shaft into neutral, forward, or reverse, with the propeller shaft being driven by an output power of an internal combustion engine. The engine electronic control unit can be operative to control a drive state of an internal combustion engine. The remote controller can be operative to transmit a control signal to the internal combustion engine electronic control unit to achieve a target drive state. The ignition control means can be operative to initiate an ignition cutout in the engine when an operating position signal from a lever position detector, which can be operative to detect an operating position of the control lever, indicates that the control lever is in a neutral position and when a shift position signal from a shift position detector indicates a shift position is not in neutral.
In another embodiment, the ignition control means can be operative to terminate the ignition cutout of the internal combustion engine while the shift cutout is implemented by the ignition control means, if the operating position signal from the lever position detector indicates the control lever position is not in a neutral position.
In yet another embodiment, the ignition control means can be operative to terminate the ignition cutout of the internal combustion engine while the shift cutout is implemented by the ignition control means if the shift position signal from the shift position detector indicates that the shift position has been kept in a neutral position for a predetermined period of time or longer.
In yet another embodiment, a plurality of shift position detectors have multiple circuits that are in electrical communication with the ignition control means and the shift position detector.
The above-mentioned and other features of the inventions disclosed herein are described below with reference to the drawings of the preferred embodiments. The illustrated embodiments are intended to illustrate, but not to limit the inventions. The drawings contain the following figures:
The following is a description of embodiments that are arranged and configured in accordance with certain features, aspects and advantages of the present inventions. This description makes reference to
Additionally, as shown in
The shift controller 15 of the engine-side ECU 10 can send a shift control signal to control operation of the shift actuator 14 based at least in part upon an operation state (operation position) of the control lever 5. The engine 9 can include a shift position detector 19 that can be operative at least to monitor the movement of the shift actuator 14. In response to any movement of the shift actuator 14, the shift position detector 19 can send a shift position signal to the shift controller 17 as feedback to indicate a shift position such as “forward,” “neutral,” and “reverse.” To achieve a similar feedback control, the throttle position detector 20, which can be used to detect an operation state of the throttle actuator 11, can be connected with the throttle control device 12. Further, the ignition timing detector 21, which can be used to detect an operation state of the spark plug 16, can be connected with the ignition control device 17.
In some embodiments, the shift position detector 19 can include multiple circuits to facilitate connection with the ignition controller 17. In this manner, the reliability of the shift cutout control system can be improved because the normal shift cutout can be achieved even in the case of failure in the shift position detector 19 or in the circuit between the ignition controller 17 and the shift position detector 19.
The dog clutch 27 can be connected with the slider 29, which can slide in the axial direction of the propeller shaft 24 with the crossing pin 28. The slider 29 can be configured with a front head end connected with the shifter 30 to facilitate rotation. The shifter 30 can be connected by a cam linkage with a cam 32. The cam 32 can be coupled to a bottom end of a shift rod 31. When the shift rod 31 is rotated around the axis to rotate the cam 32, the shifter 30 can move to the front (F) or to the rear (R) accordingly. Thus, the shifter 30 can slide back and forth to cause the dog clutch 27 to engage with either of the forward gear 25 or the reverse gear 26. In this manner, a rotation of the pinion 23 can be transmitted to the front shaft portion 24b as a rotational force in the forward direction or in the reverse direction. Subsequently, the rotational force transmitted to the front shaft portion 24b is passed to the rear shaft portion 24a, which can be coupled thereto.
As shown in
As also illustrated in
In addition, the lever position detector 18 can be used for detecting the current operating position of the control lever 5, and for transmitting the detected data to the remote-side ECU 7. Thus, the remote-side ECU 7 can receive both the input of the shift position data and the operating position data of the control lever 5. Further, an arithmetical unit (not shown) in the remote-side ECU 7 can process these input data to perform control operations for developing instructions related at least to the required ignition cutout. Instructions regarding the control operations and the extent of ignition cutout required for controlling the internal combustion engine 9 can then be transmitted to the ignition controller 17.
More specifically, once the main switch of the shift cutout control system is turned on, a start-up state J1 changes into a normal state J2 as shown in
The shift cutout state J3 can be canceled to resume the normal state J2. In some embodiments, a signal for terminating the ignition cutout on the engine 9 can be transmitted to the ignition controller 17. For example, the lever position detector 18 can transmit the operation position signal indicating that the control lever 5 is not in a neutral position and accordingly, the shift cutout state J3 can be canceled to resume the normal state J2. In another example, the shift position detector 19 can transmit the shift position signal indicating that the control lever 5 has been in a neutral shift position for at least a given period of time or that the shift position is neutral. In such cases, a signal for terminating the ignition cutout on the internal combustion engine 9 can be transmitted to the ignition controller 17 to cancel the shift cutout state J3 and to resume the normal state J2.
In accordance with some embodiments, the shift cutout reduces the torque of the engine 9 to facilitate shifting of the gears into neutral, for instance. As described above, the torque can be reduced by suspending the operation of the engine 9 through the ignition cutout of the engine 9. The shift cutout can therefore change the number of ignition suspended cylinders in accordance with the rotational speed of the engine 9. For example, in the case of a six-cylinder internal combustion engine, ignition cutout may require that the ignition is suspended in: (1) all six cylinders if the engine speed is at or over about 8000 rpm; (2) five cylinders if the engine speed is between approximately 1500 rpm to approximately 8000 rpm; (3) four cylinders if the engine speed is between approximately 850 rpm to approximately 1500 rpm; (4) three cylinders if the engine speed is between approximately 700 rpm to approximately 850 rpm; (5) two cylinders if the engine speed is between approximately 600 rpm to approximately 700 rpm; (6) one cylinder if the engine speed is between approximately 500 rpm to approximately 600 rpm; and (7) none of the cylinders if the rotational speed of the engine is less than approximately 500 rpm.
Therefore, in accordance with one of the embodiments disclosed herein, a compact and highly reliable shift cutout control system is provided that can eliminate the need for a shift cutout switch requiring mechanical or manual operation. Embodiments can simplify operation of the motor 1 by monitoring the operating position of the control lever 5 and the rotational speed of the engine 9. When necessary or desired, the ignition controller 17 can automatically initiate ignition cutout of the engine 9. Thus, shift cutout performance is not dependent on the quality of a shift cutout switch.
In addition, it is contemplated that the shift cutout control system can remain active even though the shift cutout is terminated. Thus, after shift cutout has been triggered, and the operating position signal is transmitted to the ignition controller 17 indicating that the position of the control lever 5 is not in a neutral position, the ignition controller 17 can terminate the ignition cutout in the engine 9. In such a circumstance, the shift cutout control system can continue to operate accordingly.
Further, the shift cutout can be maintained when the shift position sensor indicates the control lever 5 is in the neutral position, regardless of the fact that the gearshift is still engaged. Continued engagement of the gearshift after the control lever 5 is in the neutral position can be caused by torsional deformation of the long shift rod 31. Some embodiments can tend to mitigate against such continued engagement of the gearshift by maintaining the shift cutout; this can be performed, as mentioned above, with the ignition controller 17 terminating the ignition cutout of the engine 9 only after the shift position signal has identified the neutral shift position for at least a given period of time. Alternatively, embodiments are provided wherein the shift position signal can indicate the neutral shift position and thereby facilitate disengagement of the gearshift.
Still further, embodiments disclosed herein can be beneficially employed in vehicles such as watercraft and the like. For example, as mentioned above, embodiments of the shift cutout control system can eliminate the need for manual operation of the shift cutout switch to effect shift cutout. Further, shift cutout performance of the watercraft would not depend on the quality of the shift cutout switch. In addition, embodiments disclosed herein could provide a highly reliable shift cutout system for a watercraft or other vehicle and eliminate the need for providing an area in or around an engine 9 for mounting a shift cutout switch.
Embodiments of the shift cutout control system can be configured such that the engine-side ECU 10 of the engine 9 and the remote-side ECU 19 of the remote controller 6 can operate in combination with each other to carry out the target control. However, the present inventions are not limited to the above-mentioned embodiments. Alternative constructions and configurations may be applied in which one or more functions of the remote-side ECU 19 can be incorporated into the engine-side ECU 10 to eliminate the remote-side ECU 19, for instance.
Although these inventions have been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present inventions extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the inventions and obvious modifications and equivalents thereof. In addition, while several variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combination or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above.
Number | Date | Country | Kind |
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2006-140539 | May 2006 | JP | national |
Number | Name | Date | Kind |
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6942530 | Hall et al. | Sep 2005 | B1 |
20060135314 | Shomura et al. | Jun 2006 | A1 |
Number | Date | Country |
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02-216391 | Aug 1990 | JP |
Number | Date | Country | |
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20070270054 A1 | Nov 2007 | US |