Abstract:
A system is disclosed for implementing a technique for idling a diesel engine. The system comprises an engine controller, an air temperature sensor, and an engine speed sensor. The air temperature sensor provides a first signal indicative of an internal temperature of an intake manifold in fluid communication with the diesel engine. The engine speed sensor provides a second signal indicative of a rotational speed of a crankshaft of the diesel engine. In response to various other signals collectively indicating the diesel engine is idling, the engine controller controls the supply of fuel to the diesel engine as a function of the first signal. When the first signal is below a temperature level, engine controller supplies fuel to each combustion chamber of the diesel engine for a fixed period of time to achieve a desired range of rotational speeds of the crankshaft as indicated by the second signal. Thereafter, the engine controller supplies fuel to a subset of the combustion chambers to achieve a higher range of rotational speeds of the crankshaft as indicated by the second signal. When the first signal is at or above the temperature level, engine controller supplies fuel to each combustion chamber of the diesel engine to achieve a desired range of rotational speeds of the crankshaft as indicated by the second signal.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention generally relates to control methods and systems for diesel engines, and more specifically, but not exclusively, relates to a technique for injecting fuel into a first set of one or more combustion chambers and/or a second set of one or more combustion chambers of the diesel engine when idling the diesel engine based upon temperature ambient the diesel engine. 
     BACKGROUND OF THE INVENTION 
     A diesel engine in an idling state can experience incomplete combustion of fuel within the combustion chambers of the diesel engine if the temperature ambient the diesel engine is too low. As a result, structural damage to the diesel engine can occur. For example, while a diesel engine is idling at an ambient temperature of 10° F. or less, distillates of unburned fuel within a combustion chamber may precipitate on a corresponding valve of the diesel engine. Consequently, the valve can get stuck within a respective valve seat whereby a corresponding push tube of the diesel engine can be bent. Therefore, there is a need for an engine control method and system for diminishing, if not eliminating, any potential creation of distillates within the combustion chambers of a diesel engine while the diesel engine is idling. 
     SUMMARY OF THE INVENTION 
     The objective of the present invention is to address the need for significantly decreasing, if not eliminating, any potential creation of distillates within a combustion chamber while a diesel engine is idling. Various aspects of the present invention are novel, nonobvious, and provide various advantages. While the actual nature of the invention covered herein can only be determined with reference to the claims appended hereto, certain features which are characteristic of the various forms disclosed herein are described briefly as follows. 
     One form of the present invention is a unique method for injecting fuel into only a first set of combustion chambers of a diesel engine while the diesel engine is idling in a first state, and injecting fuel into both the first set of combustion chambers and a second set of combustion chambers of the diesel engine while the diesel engine is idling in a second state. The first state and the second state are based upon the temperature ambient to the diesel engine. 
     Another form of the present invention is a unique vehicle comprising a diesel engine and a controller. The controller is operable to control an injection of fuel into only a first set of combustion chambers of the diesel engine while the diesel engine is idling in a first state. The controller is further operable to control an injection of fuel into both the first set of combustion chambers and a second set of combustion chambers of the diesel engine while the diesel engine is idling in a second state. The first state and the second state are based upon the temperature ambient to the diesel engine. 
     Further forms, objects, features, aspects, benefits, and advantages of the present invention will become apparent from the drawings and description contained herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of one embodiment a vehicle of the present invention. 
     FIG. 2 is a flow chart of one embodiment of an engine fueling management procedure of the present invention for operating a FIG. 1 diesel engine. 
     FIG. 3 is a flow chart of one embodiment of an engine fueling routine of the present invention for idling the FIG. 1 diesel engine. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purposes of promoting an understanding of the principles of the present invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present invention is thereby intended. Any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the present invention as illustrated herein being contemplated as would normally occur to one skilled in the art to which the present invention relates. 
     FIG. 1 depicts a vehicle  10  comprising a vehicle chassis/body  11  defining an engine compartment  12  and an operator compartment  13 . While vehicle  10  can be any type of vehicle, preferably vehicle  10  is a light-duty truck. Within compartment  12 , vehicle  10  comprises a diesel engine  20  (hereinafter “engine  20 ”), an intake manifold  30 , a throttle  40 , a fueling system  50 , and a transmission  60 . 
     Engine  20  is of the four stroke diesel-fueled type with Compression Ignition (CI) having intake manifold  30  is in fluid communication therewith. In other embodiments, engine  20  can be a different type of engine as would occur to one skilled in the art, e.g. a two stroke diesel-fueled types, a four stroke crude oil fueled internal combustion engine, etc. Engine  20  includes a combustion chamber  21 , a combustion chamber  22 , a combustion chamber  23 , a combustion chamber  24 , a combustion chamber  25 , a combustion chamber  26 , and a crankshaft  27 . The present description of engine  20  is directed to the primary components of engine  20  interacting with an engine fueling management system of the present invention, with other standard components of engine  20  as would be known to one skilled in the art not being specifically described herein. It should be appreciated that engine  20  is being schematically represented and that more or fewer combustion chambers may be employed as would occur to one skilled in the art. 
     An accelerator pedal  41  within compartment  13  be manipulated, physically or electrically, by an operator of vehicle  10  from a rotational position of 0% at one extreme to a rotational position of 100% at the other extreme. Throttle  40  is operatively coupled to pedal  41  to thereby synchronously rotate with pedal  41  between the 0% rotational position and 100% rotational position. The 0% rotational position represents an idle position for throttle  40 . 
     Fueling system  50  includes a fuel source (not shown), e.g. a fuel tank, to thereby supply fuel by a fuel pathway  51  to combustion chambers  21 - 26  in accordance with a firing order as established by the engine fueling management system of the present invention. Fuel pathway  51  represents one or more fuel lines, signal paths, and/or other type of engine connections associated with conventional fueling systems. Preferably, engine  20  is configured for chamber-injection fueling, and fueling system  50  includes electronically controlled fuel injectors. Alternatively, other fueling arrangements may be utilized as would occur to one skilled in the art. 
     Transmission  60  includes a torque converter (not shown) operatively coupled to crankshaft  27 . Transmission  60  is a combination mechanical and shift-by-wire type of automatic transmission. In other embodiments, transmission  60  can be a different type of transmission as would occur to one skilled in the art, e.g. a mechanical type of automatic transmission, a shift-by-wire type of transmission, a manual transmission, etc. A propeller shaft  70  is operatively coupled to transmission  60 . A drive axle  71  is operatively coupled to propeller shaft  70 . A pair of wheels  73   a  and  73   b  are operatively coupled to a drive axle  72 . A pair of wheels  73   c  and  73   d  are operatively coupled to drive axle  71 . Engine  20  is the prime mover for vehicle  10  that provides mechanical power to transmission  60  whereby propeller shaft  70 , drive axle  71 , drive axle  72 , wheel  73   a , wheel  73   b , wheel  73   c , and wheel  73   d  are rotated. 
     Within compartment  13 , vehicle  10  also comprises a brake pedal  80 . Brake pedal  80  can be manipulated by an operator of vehicle  10  from a rotational position of 0% at one extreme to a rotational position of 100% at the other extreme. Brake pedal can be any type of pedal. 
     Still referring to FIG. 1, one embodiment of the engine fueling management system of the present invention includes a engine controller  90  , an vehicle controller  100 , a coolant temperature sensor  28 , an air temperature sensor  31 , a throttle position sensor  42 , a vehicle speed sensor  74 , and a brake position sensor  81 . Engine controller  90  and vehicle controller  100  are preferably electronic subsystems, each being comprised of one or more components of a common engine control unit (hereinafter “the common ECU”) (not shown) that is powered by a battery (not shown). Engine controller  90  and vehicle controller  100  may include digital circuitry, analog circuitry, and/or hybrid circuitry. Engine controller  90  and vehicle controller  100  can include multiple components that are physically positioned at different locations within vehicle  10 . In the illustrated embodiment, engine controller  90  includes a memory  91  and a central processing unit  92  (hereinafter “CPU  92 ”), and engine controller includes a memory  101  and a central processing unit  102  (hereinafter “CPU  102 ”). 
     Memory  91  and memory  101  are of the solid-state electronic variety, and may be embodied in one or more components. In other embodiments, memory  91  and memory  101  may alternatively or concurrently include magnetic or optical types of memory. Memory  91  and memory  101  can be volatile, nonvolatile, or a combination of both volatile and nonvolatile types of memory. While it is preferred that memory  101  be integrally included in the common ECU and memory  91  be remotely distributed for access via a local area network  110  (hereinafter “LAN  110 ”), in other embodiments, memory  91  is remotely distributed for access via LAN  110  and/or memory  101  is integrally included in the common ECU. In still other embodiments, memory  91  and memory  101  are provided by a single integral memory. 
     CPU  92  is configured to access memory  91   101  and is remotely distributed for access via LAN. CPU  92  is a programmable, microprocessor-based device that executes instructions stored in memory  91 , and accesses memory  91  to read or write data in accordance with the instructions. CPU  102  is configured to access memory  110  and is mounted on the common ECU. CPU  102  is a programmable, microprocessor-based device that executes instructions stored in memory  101 , and accesses memory  101  to read or write data in accordance with the instructions. In other embodiments, CPU  92  is integrally included in the common ECU and/or CPU  102  is remotely distributed for access via LAN  110 . In yet other embodiments, CPU  92  and/or CPU  102  can alternatively be implemented as a dedicated state machine, or a hybrid combination of programmable and dedicated hardware. In still other embodiments, engine controller  90  and vehicle controller  100  are provided by a single integral processing unit. Engine controller  90  and vehicle controller  100  further include any interfaces, control clocks, signal conditioners, signal converters, filters, communication ports, or any other type of operators as would occur to one skilled in the art to implement the principles of the present invention. 
     Still referring to FIG. 1, engine controller  90  is in electrical communication with fueling system  50  by a signal path  93  to thereby provide a fueling meter signal FM s  that is indicative of a level of fuel to be supplied to a selected combustion chamber of combustion chambers  21 - 26 . Specifically, an active fuel injector (not shown) of fueling system  50  conventionally expels fuel therefrom at a fixed rate. Fueling meter signal FM s  informs fueling system  50  of a fixed length of time to activate the fuel injector such that a desired level of fuel is supplied to the selected combustion chamber. Vehicle controller  100  is in electrical communication with transmission  60  by a signal path  61  to exchange a plurality of transmission management signals TM s  for managing the operation of transmission  60 , and a plurality of transmission condition signals TC s  that are indicative of the operating state of transmission  60 . Engine controller  90  receives a transmission operation signal TO s  from vehicle controller  100  via LAN  110  wherein vehicle condition signal VO s  is also indicative of an operating state of the various components of vehicle  10  other than engine  20  and associated components of vehicle  10 . 
     Coolant temperature sensor  28  is in electrical communication with engine controller  90  by a signal path  29 . Coolant temperature sensor  28  is a conventional temperature sensor positioned within respect to a cooler passage (not shown) of engine  20  to thereby provide a coolant temperature signal CT s  to engine controller  90  via signal path  29 . Coolant temperature signal CT s  is an indication of the internal temperature of the coolant with the cooler passage. 
     Air temperature sensor  31  is in electrical communication with engine controller  90  by a signal path  32 . Air temperature sensor  31  is a conventional temperature sensor positioned within intake manifold  30  to thereby provide a air temperature signal AT s  to engine controller  90  via signal path  32 . Air temperature signal AT s  is an indication of the internal temperature of intake air within intake manifold  30 . As will be further described herein, temperature signal AT s  is utilized as a representation of a temperature ambient engine  20 . 
     Throttle position sensor  42  is in electrical communication with engine controller  90  by a signal path  43 . Throttle position sensor  42  is a conventional magnetic sensor positioned with respect to throttle  40  to thereby provide a throttle position signal TP s  to engine controller  90  via signal path  43 . Throttle position signal TP s  is an indication of a rotational position of throttle  40 . Alternatively or additionally, throttle position signal TP s  can be derived from a detected rotational position of accelerator pedal  41  which can be manually operated or electronically operated by a cruise control system as taught by commonly owned U.S. Pat. No. 5,738,606, that is hereby incorporated by reference. 
     Engine speed sensor  62  is in electrical communication with engine controller  90  by a signal path  63 . Engine speed sensor  62  is a conventional magnetic sensor positioned with respect to crankshaft  27  to thereby provide an engine speed signal ES s  to engine controller  90  via signal path  63 . Engine speed signal ES s  is an indication of a rotational speed of crankshaft  27 . Engine speed sensor  62  can alternatively be positioned with respect to propeller shaft  70  to thereby provide engine speed signal ES s  as would occur to one skilled in the art. 
     Vehicle speed sensor  74  is in electrical communication with vehicle controller  100  by a signal path  75 . Vehicle speed sensor  74  is conventional magnetic sensor positioned relative to wheel  73   b  to provide a vehicle speed signal VS s  to vehicle controller  100  via signal path  75 . Vehicle speed signal VS s  is an indication of a rotational speed of wheels  73   a - 73   d.    
     Brake position sensor  81  is in electrical communication with vehicle controller  100  by a signal path  82 . Brake position sensor  81  is a conventional magnetic sensor positioned with respect to brake pedal  80  to thereby provide a brake position signal BP s  to vehicle controller  100  via signal path  82 . Brake position signal BP s  is an indication of a rotational position of brake pedal  80 . 
     In other embodiments of the present invention, coolant temperature signal CT s , air temperature signal AT s , throttle position signal TP s , engine speed signal ES s , vehicle speed signal VS s  and/or brake position signal BP s  can be provided by other types of sensors. 
     Referring additionally to FIG. 2, one embodiment of an engine fueling management procedure  120  for implementing the engine fueling management technique of the present invention is shown. Procedure  120  is implemented by engine controller  90  upon receipt of a signal from vehicle controller  100  via LAN  110  indicating that an ignition switch (not shown) of vehicle  10  is positioned in a START position or an ON position. During stage S 122  of procedure  120 , coolant temperature signal CT s , throttle position signal TP s , vehicle speed signal VS s , brake position signal BP s  and a gear position signal GP s  are received by engine controller  90  as well as other signals known to one skilled in the art. Gear position signal GP s  is embedded within transmission condition signals TC s  as received by vehicle controller  100 , and is indicative of a gear position of transmission  60 , e.g. 1 St  gear, 2 nd  gear, park, neutral, etc., as would occur to one skilled in the art. Coolant temperature signal CT s , throttle position signal TP s , vehicle speed signal VS s , brake position signal BP s  and gear position signal GP s  are continually received thereafter by engine controller  90  until the ignition switch is positioned in an OFF position. 
     During stage S 124  of procedure  120 , engine controller  90  initially determines whether engine  20  is operating in a drive state or an idle state. For the embodiment of vehicle  10  illustrated herein, engine controller  90  makes this initial determination as a function of coolant temperature signal CT s , throttle position signal TP s , vehicle speed signal VS s , brake position signal BP s  and gear position signal GP s . For the illustrated embodiment, engine  20  is operating in an idle state when coolant temperature signal CT s  indicates a coolant temperature less than or equal to 140° F., throttle position signal TP s  indicates throttle valve  41  is at the 0% position, vehicle speed signal VS s  indicates a vehicle speed less than or equal to 2 MPH, brake position signal BP s , brake position signal TP s  indicates brake pedal  80  is at the 0% position, and gear position signal GP s  indicates transmission  60  is in park or neutral. Engine  20  is operating in a drive state if any one of the above mentioned parameters for the signals is not initially indicated. Engine  20  is operating in a drive state after an determined idle state if any of the above mentioned parameters for throttle position signal TP s , vehicle speed signal VS s , brake position signal BP s  and transmission condition signal TC s  are no longer being indicated or coolant temperature signal CT s  indicates a coolant temperature greater than 175° F. 
     In other embodiments, different parameters for coolant temperature signal CT s , throttle position signal TP s , vehicle speed signal VS s , brake position signal BP s  and/or gear position signal GP s  are utilized to determine if engine  20  is operating in an idle state. In still other embodiments, other signals as would occur to one skilled in the art can concurrently or alternatively be received during stage S 122  to determine if engine  20  is operating in an idle state. 
     If engine controller  90  determines engine  20  is operating in a drive state during stage S 122 , engine controller  90  executes a conventional engine fueling routine  130  as would occur to one skilled in the art for supplying fuel to combustion chambers  21 - 26  in a specific firing order. If engine controller  90  determines engine  20  is operating in an idle state during stage S 122 , engine controller  90  executes a unique engine fueling routine  140  for supplying fuel to either combustion chambers  21 - 26  in a specific firing order, or combustion chambers  21 ,  23 , and  25  in a specific firing order. Engine controller  90  continually determines the operating state of stage S 122  until the ignition switch is positioned in an OFF position. Consequently, it is to be appreciated that routine  130  is being executed while routine  140  is not being executed, and vice-versa. 
     Referring additionally to FIG. 3, one embodiment of an engine fueling routine  140  of the present invention is shown. During stage S 142  of routine  140 , air temperature signal AT s  and engine speed signal ES s  are received by engine controller  90  as well as other signals as known to one skilled in the art. Air temperature signal AT s  and engine speed signal ES s  are continually received thereafter by engine controller  90  until routine  140  is terminated or the ignition switch is positioned in an OFF position. 
     Engine controller  90  determines if air temperature signal AT s  is less than or equal to 15° F. during stage S 144  of routine  140 . For this embodiment, air temperature signal AT s  being less than or equal to 15° F. is representative of a temperature ambient to engine  20  for facilitating the creation of distillates within combustion chambers  21 - 26 . For other embodiments, air temperature signal AT s  can be tested during stage S 144  against a different temperature that is considered representative of a temperature ambient to engine  20  for facilitating the creation of distillates within combustion chambers  21 - 26 . 
     Engine controller  90  proceeds to stage S 146  of routine  140  if engine controller  90  determines air temperature signal AT s  is less than or equal to 15° F. During stage S 146 , engine controller  90  provides fueling meter signal FM s  to fueling system  50  via path  93  whereby fueling system  50  supplies fuel to combustion chambers  21 - 26  for a fixed period of time in response to fueling meter signal FM s . Consequently, the firing order for stage S 146  includes all six (6) combustion chambers  21 - 26 . Preferably, if air temperature signal AT s  is less than or equal to 0° F. fueling system  50  supplies fuel to combustion chambers  21 - 26  for twenty (20) seconds whereby crankshaft  27  is rotated at approximately 1,000 RPM as indicated by engine speed signal ES s . It is also preferred that if air temperature signal AT s  is greater than 0° F. and less than or equal to 15° F., fueling system  50  supplies fuel to combustion chambers  21 - 26  for one (1) minute whereby crankshaft  27  is rotated at approximately 800 RPM as indicated by engine speed signal ES s . 
     Upon completion of stage S 146 , engine controller  90  proceeds to stage  148  of routine  140 . During stage S 148 , engine controller  90  provides fueling meter signal FM s  to fueling system  50  via path  93  whereby fueling system  50  supplies fuel to combustion chambers  21 ,  23 , and  25  in response to fueling meter signal FM s . Consequently, the firing order for stage S 146  includes only combustion chambers  21 ,  23 , and  25 . Preferably, if air temperature signal AT s  is less than or equal to 0° F., fueling system  50  supplies fuel to combustion chambers  21 ,  23 , and  25  whereby the rotation of crankshaft  27  is accelerated from approximately 1,000 RPM to approximately 1,200 RPM at a rate of 13 RPM/sec as indicated by engine speed signal ES s . It is also preferred that if air temperature signal AT s  is greater than 0° F. and less than or equal to 15° F., fueling system  50  supplies fuel to combustion chambers  21 ,  23 , and  25  whereby the rotation of crankshaft  27  is accelerated from approximately 800 RPM to approximately 1200 RPM at a rate of 13 RPM/sec as indicated by engine speed signal ES s . 
     It is to be appreciated that stage S 146  and stage S 148  are executed during an idle state of engine  20  whereby distillates of unburned fuel with combustion chambers  21 - 26  could be created therein as indicated by air temperature signal AT s . It is to be further appreciated that substantial, if not complete, combustion of fuel within combustion chambers  21 ,  23 , and  25  occurs during stage S 148  due to the increased amount of power combustion chambers  21 ,  23 , and  25  must provide to accelerate crankshaft  27 . Thus, the creation of distillates within combustion chambers  21 - 26  is diminished, if not eliminated. In other embodiments of the present invention, any number less than all six (6) of combustion chambers  21 - 26  can receive fuel during stage S 148  whereby substantial, if not complete, combustion is occurring within the combustion chambers receiving fuel. 
     Engine controller  90  proceeds to stage S 150  of routine  140  if vehicle controller  100  determines air temperature signal AT s  is greater than 15° F. During stage S 150 , vehicle controller  100  provides fueling meter signal FM s  to fueling system  50  via path  93  whereby fueling system  50  supplies fuel to combustion chambers  21 - 26  in response to fueling meter signal FM s . Consequently, the firing order for stage S 150  includes all six (6) combustion chambers  21 - 26 . Preferably, if air temperature signal AT s  is greater than 15° F. and less than or equal to 32° F., fueling system  50  supplies fuel to combustion chambers  21 - 26  for one (1) minute whereby crankshaft  27  is rotated at approximately 800 RPM as indicated by engine speed signal ES s , and thereafter accelerates crankshaft  27  from approximately 800 RPM to approximately 1,200 RPM at a rate of 13 RPM/sec. It is also preferred that if air temperature signal AT s  is greater than 32° F., fueling system  50  supplies fuel to combustion chambers  21 - 26  whereby crankshaft  27  is rotated at approximately 800 RPM as indicated by engine speed signal ES s . 
     It is to be appreciated that stage S 150  is executed during an idle state of engine  20  when there is a no risk as indicated by air temperature signal AT s  of distillates being created within combustion chambers  21 - 26  due to unburned fuel therein. It is to be further appreciated that engine controller  90  is continually monitoring air temperature signal AT s . Consequently, engine controller  90  can be shifting back and forth between stage S 146  and stage S 148 , collectively, and stage S 150  whenever air temperature signal AT s  is fluctuating around 15° F. or whatever the temperature parameter may be. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.