Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/008—Controlling each cylinder individually
  • F02D41/0087—Selective cylinder activation, i.e. partial cylinder operation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D17/00—Controlling engines by cutting out individual cylinders; Rendering engines inoperative or idling
  • F02D17/02—Cutting-out
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
  • F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
  • F02D35/023—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions by determining the cylinder pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/04—Introducing corrections for particular operating conditions
  • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
  • F02D41/062—Introducing corrections for particular operating conditions for engine starting or warming up for starting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/04—Introducing corrections for particular operating conditions
  • F02D41/06—Introducing corrections for particular operating conditions for engine starting or warming up
  • F02D41/068—Introducing corrections for particular operating conditions for engine starting or warming up for warming-up
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
  • F02B2275/16—Indirect injection
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/40—Engine management systems

Definitions

• the present invention relates, in general, to a starting control method of a car for reducing the emission of noxious gas including unburned hydrocarbons, and, more particularly, to a starting control method of a car for reducing the emission of noxious gas including unburned hydrocarbons, which skips fuel injection into some cylinders while an engine cycles 1 to 3 times after an initial start or.
• the gasoline engine is also called a reciprocating type spark ignition internal combustion engine.
• air is compressed in a cylinder at a volume ratio of about 1:20 to raise a temperature in a combustion chamber to 500 ⁇ 700°C, and a petroleum fuel, such as kerosene, light oil or heavy oil, which has a vaporization characteristic inferior to gasoline and cannot be easily vaporized by a carburetor, is injected into the air in the cylinder having high temperature and high pressure, so that the fuel can be spontaneously fired and burned. Therefore, the diesel engine is also called a reciprocating type compression firing internal combustion engine .
• the gasoline engine and diesel engine used in a car are slightly different from each other in terms of combustion pattern, they have substantially similar structures in that they belong to an internal combustion engine in which a mixture or petroleum fuel is injected into four or six cylinders of a four- cylindered or six-cylindered engine at a proper volume ratio depending upon the desired output power, the mixture or petroleum fuel injected into the cylinders is sequentially burned in combustion chambers defined in the respective cylinders, and a crankshaft connected to pistons is rotated by explosion force generated due to the combustion of fuel in the cylinders to produce power. Accordingly, in an engine, the combustion of fuel in cylinders should be appropriately implemented to improve engine performance and output power and reduce the amount of noxious gas exhausted from the car.
• a problem is caused in that, since a part of the fuel condensed on the cold inner wall surface of the cylinder begins to vaporize after the fuel is ignited (in the case of the gasoline engine) or fired (in the case of the diesel engine) , the emission of unburned hydrocarbons (HC) significantly increases due to incomplete combustion. Also, if a phenomenon in which part of the vaporized fuel re-condenses on the cold inner wall surface of the cylinder occurs, the emission of noxious gases including unburned hydrocarbons (HC) increases to a serious level . Further, in these days, due to the rapid popularization of cars, traffic congestion occurs all the time including during rush hour.
• an idle-stop system is installed on most cars having high fuel economy to automatically stop the operation of the engine when 3 to 5 seconds lapse after a car stops, thereby preventing unnecessary fuel consumption.
• a cold start state is repeated to cause atmospheric pollution due to the emission of noxious gas including unburned hydrocarbon.
• FIG. 1 is a schematic view of an in-line engine
• FIG. 2 is a schematic view of a V-shaped engine
• FIG. 3 is a schematic view of an opposed type engine
• FIG. 4 is a schematic view illustrating an experimental device which is applied to a control method according to the present invention
• FIG. 5 is a flow chart illustrating the control method according to the present invention
• FIG. 6 is a graph illustrating the results obtained by applying fuel skip cycles under a condition where a temperature of cooling water is 30°C
• FIG. 7 is a graph illustrating the results obtained by applying fuel skip cycles under a condition where a temperature of cooling water is 50°C
• FIG. 8 is a graph illustrating the results obtained by applying fuel skip cycles under a condition where a temperature of cooling water is 70°C
• FIG. 9 is a graph illustrating the results obtained by applying fuel skip cycles under a condition where a temperature of cooling water is 90°C
• FIG. 10 is a graph illustrating the unburned hydrocarbon emission reducing effect accomplished by the control method according to the present invention
• FIG. 11 is a graph comparing CO measurements in the CVS 75 test mode
• FIG. 12 is a graph comparing NOx measurements in the
• FIG. 13 is a graph comparing NMHC measurements in the CVS 75 test mode;
• FIG. 14 is a graph comparing C0 2 measurements in the CVS 75 test mode;
• FIG. 15 is a graph comparing F.E. and C0 2 measurements in the CVS 75 test mode;
• FIG. 16 is a graph comparing exhaust emission measurements and allowable limits in the CVS 75 test mode;
• FIG. 17 is a graph comparing CO measurements in the
• FIG. 18 is a graph comparing NOx measurements in the ECE15+EUDC test mode;
• FIG. 19 is a graph comparing NMHC measurements in the ECE15+EUDC test mode;
• FIG. 20 is a graph comparing C0 2 measurements in the ECE15+EUDC test mode;
• FIG. 21 is a graph comparing F.E. and C0 2 measurements in the ECE15+EUDC test mode;
• FIG. 22 is a graph comparing exhaust emission measurements and allowable limits in the ECE15+EUDC test mode;
• FIG. 23 is a graph comparing CO measurements in the Modal test mode;
• FIG. 24 is a graph comparing NOx measurements in the Modal test mode;
• FIG. 25 is a graph comparing NMHC measurements in the Modal test mode;
• FIG. 26 is a graph comparing C0 2 measurements in the Modal test mode;
• FIG. 27 is a graph comparing F.E. measurements in the
• FIG. 28 is a graph comparing F.E. and C0 2 measurements in the Modal test mode
• FIG. 29 is a graph comparing exhaust emission measurements and allowable limits in the Modal test mode.
• an object of the present invention is to provide a starting control method of a car for reducing the emission of noxious gases including unburned hydrocarbons, which skips fuel injection into some cylinders while an engine cycle proceeds 1 to 3 times after an initial start or a restart following an idle stop, such that the internal temperatures of the cylinders not injected with fuel are raised in advance with the aid of compression heat by pistons and, with the internal temperatures of the cylinders raised to predetermined levels in this way, normal fuel injection into the cylinders can be implemented, thereby reducing the emission of noxious gas including unburned hydrocarbons, the unburned hydrocarbons being otherwise generated due to the incomplete combustion of fuel when initially starting or restarting after idle stop.
• a starting control method of a car having several cylinders to be ignited in a predetermined ignition sequence to thereby complete a normal combustion cycle comprising the steps of: (a) judging whether or not an engine is in a starting state or a restarting state; and (b) repeating one or more times a fuel skip cycle in which ignition and skip are alternately implemented in the predetermined ignition sequence of the cylinders, when it is judged that the engine is in the starting state or the restarting state.
• the skip comprises interrupting the fuel supply to a cylinder.
• the predetermined ignition sequence begins with any one of the ignition and skip.
• the fuel skip cycle is repeated one to three times .
• fuel injection into cylinders is skipped while an engine cycles 1 to 3 times after an initial start or a restart following an idle stop, such that the internal temperatures of the cylinders not injected with fuel are raised in advance with the aid of compression heat due to the movement of pistons and, with the internal temperatures of the cylinders raised to predetermined levels in this way, normal fuel injection into the cylinders can occur, whereby it is possible to reduce the emission of noxious gases including unburned hydrocarbons which are otherwise generated due to the incomplete combustion of fuel when initially starting or restarting after an idle stop.
• An essential technical feature of the present invention is that, when an engine is started in a stopped state or is restarted after being automatically stopped by an idle-stop system, the ignition of the engine is implemented in conformity with an ignition sequence of the cylinders so that ignition and skip alternate with each other to raise the temperature of wall surfaces of combustion chambers of cylinders not injected with fuel to thereby induce complete combustion when fuel is injected into those cylinders . Therefore, since the engine can be sufficiently pre- heated, a cold starting state is avoided, whereby it is possible to reduce the emission of noxious gas including unburned hydrocarbons (HC) due to the incomplete combustion of fuel.
• HC unburned hydrocarbons
• the method according to the present invention largely comprises a start or restart judging step and a fuel skip cycle step. Whether or not the engine is in a starting state or a restarting state can be judged considering the operating information of the fuel injection valves for injecting fuel into the cylinders or of the ignition plugs for igniting the fuel in the cylinders . If it is judged in the judging step that the engine is in a starting or restarting state, the method proceeds to the fuel skip cycle step.
• car engines are divided into in-line engines, V-shaped engines and opposed type engines, depending upon the arrangement of the cylinders .
• the inline engine has cylinders which are arranged in line on a crankshaft, the V-shaped engine has two arrays of cylinders which are arranged on the crankshaft to define a V-shaped contour, and the opposed type engine has two groups of cylinders which are arranged opposite to each other and opposed to each other by 180°.
• FIGs . 1 through 3 are conceptual views of the in-line engine, the V-shaped engine and the opposed type engine, in which cylinders are numbered in order. When viewed from the top, the cylinders of the inline engine are numbered in an ascending order from one end remote from an output shaft toward the other end adjacent to the output shaft.
• the V-shaped engine When viewed from the top, the V-shaped engine is numbered first in a left array in an ascending order from one end remote from an output shaft toward the other end adjacent to the output shaft and then in a right array in an ascending order following the last number of the left array from one end remote from the output shaft toward the other end adjacent to the output shaft.
• the opposed type engine is numbered in the same manner as the V-shaped engine.
• the fuel skip cycle step is constructed so that the ignition and skip are alternately implemented in an inherent ignition sequence of a normal cycle of an engine. For example, if an ignition sequence of a six- cylindered in-line engine is 1-5-3-6-2-4, in the fuel skip cycle ignition is implemented in sequence of 1-S-3-S-2-S or S-5-S-6-S-4.
• the character 'S' means a fuel injection skip in which fuel is not injected. Since it is sufficient that the skip is alternately implemented with the ignition, selection is made in the first cylinder between skip and ignition, and remaining cylinders are arranged in such a way as to ensure alternate implementation of the skip and ignition.
• the fuel skip cycle is implemented at least one time.
• the fuel skip cycle be implemented one to three times for sufficient heating of the engine.
• the skip comprises interrupting the fuel supply to the cylinder.
• a piston causes air to be sucked, compressed, expanded and exhausted by force supplied from ignited cylinders or driving force from a starter motor, to function to raise a temperature of the wall surface of the combustion chamber.
• normal combustion is effected in conformity with the inherent ignition sequence of the engine .
• Table 1 there are presented ignition sequences in normal cycles and ignition sequences in fuel skip cycles, depending upon the kind of engine. It is to be readily understood that ignition sequences of fuel skip cycles for engines other than those presented in Table 1 can be determined in the same manner as in Table 1.
• FIG. 4 is a schematic view illustrating an experimental device which is applied to a control method according to the present invention
• FIG. 5 is a flow chart illustrating the control method according to the present invention
• FIGs. 6 through 9 are graphs illustrating the results obtained by applying fuel skip cycles under respective temperatures of cooling water
• FIG. 10 is a graph illustrating the unburned hydrocarbon emission- reducing effect accomplished by the control method according to the present invention.
• an encoder (Koyo Co., 360ppr) 20 is installed on a camshaft 19 for operating intake and exhaust valves, in a manner such that a pulse is generated for every 2 rotation degrees of a crankshaft, that is, for every 1 rotation degree of the camshaft 19.
• the pulse generated in this way is inputted into a data acquisition system 29 by way of a frequency-voltage converter 26.
• the ECU 21 senses the fuel injection timing for each cylinder 11 to selectively control the operation of the corresponding fuel injection valve 14 and the ignition plug 15.
• the temperature of cooling water is changed to 30°C, 50°C, 70°C and 90°C using a temperature adjustment device (not shown) to conform to the same situation as the initial starting, that is, cold starting or restarting after the idle stop of a car.
• a temperature adjustment device not shown
• the unburned hydrocarbons discharged through an exhaust manifold 16 is measured by an exhaust FID probe 24 such as an FRFID (fast response flame ionization detector) which is inserted into the exhaust manifold 16 connected to the fourth cylinder lid to measure the concentration of unburned hydrocarbons in the exhaust in real time.
• FIG. 5 is a flow chart programmed in the ECU 21 of the experimental device for implementing the starting control method of a car according to the present invention.
• a judging step (S-0) is implemented by the ECU 21 to judge whether or not the engine 10 is in a starting state or restarting state
• a setting step (S-l) is implemented to set the respective sensors 22, 23 and 24 including the encoder 20, the amplifiers 25, 27 and 28, the converter 26, and the data acquisition system 29 to an operable state.
• the normal engine cycle is implemented, in which explosion strokes are effected in order of first, third, fourth and second cylinders 11a, lie, lid and lib.
• fuel injection into some cylinders 11 is skipped while the normal engine cycle is implemented. Due to the fact that a temperature in combustion chambers of the cylinders 11 which are not injected with fuel is raised in advance with the aid of compression heat of air effected by virtue of the movement of the pistons, the influence of a cooled region on a wall surface of each combustion chamber of the cylinders 11 imposed on petroleum fuel can be minimized, as a result of which is it is possible to reduce emissions including unburned hydrocarbons due to • incomplete combustion when initially starting or restarting after an idle stop.
• a pulse generated from the encoder 20 by the rotation of the camshaft 19 is inputted into the data acquisition system 29 by way of the frequency-voltage converter 26.
• the ECU 21 performs an operation task for the inputted data to determine a fuel injection timing for the first cylinder 11a.
• the ECU 21 turns off the switches 17 and 18 connected to the corresponding fuel injection valve 14 and ignition plug 15.
• a first skip step (S-2) is implemented, in a manner such that fuel injection into the first cylinder 11a and subsequent fuel combustion in the first cylinder 11a are not effected.
• a temperature in the combustion chamber of the first cylinder 11a is raised to a predetermined level with the aid of compression heat of air effected by virtue of the movement of the piston.
• a pulse generated in the encoder 20 by the rotation of the camshaft 19 is inputted into the data acquisition system 29 by way of the frequency-voltage converter 26.
• the ECU 21 performs an operation task for the inputted data to determine a fuel injection timing for the third cylinder lie.
• the ECU 21 turns on the switches 17 and 18 connected to the corresponding fuel injection valve 14 and ignition plug 15.
• a first fuel injection step (S-3) is implemented, in a manner such that fuel injection into the third cylinder lie and subsequent fuel combustion in the third cylinder lie are effected. Due to this fact, an initial driving force for operating the engine 10 is produced.
• a pulse generated in the encoder 20 by the rotation of the camshaft 19 is inputted into the data acquisition system 29 by way of the frequency-voltage converter 26.
• the ECU 21 performs an operation task for the inputted data to determine a fuel injection timing for the fourth cylinder lid.
• the ECU 21 turns off the switches 17 and 18 connected to the corresponding fuel injection valve 14 and ignition plug 15.
• a second skip step (S-4) is implemented, in a manner such that fuel injection into the fourth cylinder lid and subsequent fuel combustion in the fourth cylinder lid are not effected. Due to this, instead of fuel combustion being effected in the fourth cylinder lid, a temperature in the combustion chamber of the fourth cylinder lid is raised to a predetermined level with the aid of compression heat of air effected by virtue of the movement of the piston.
• a pulse generated in the encoder 20 by the rotation of the camshaft 19 is inputted into the data acquisition system 29 by way of the frequency-voltage converter 26. Then, the ECU 21 performs an operation processing for the inputted data to determine a fuel injection timing for the second cylinder lib.
• the ECU 21 turns on the switches 17 and 18 connected to the corresponding fuel injection valve 14 and ignition plug 15. In this way, a second fuel injection step (S-5) is implemented, in a manner such that fuel injection into the second cylinder lib and subsequent fuel combustion in the second cylinder lib are effected. Due to this fact, an additional driving force for operating the engine 10 is produced in addition to the initial driving force produced by the first fuel injection step (S-3) .
• the fuel skip cycle (SC) which is composed of the first skip step (S-2) through the second fuel injection step (S-5) as described above, one to three times after the setting step (S-l) upon initial starting, that is, cold starting or restarting after idle stop, temperatures in the combustion chambers of the first and fourth cylinders 11a and lid are raised by a predetermined level with the aid of the compression heat of air, and then, fuel injection into the respective cylinders 11 and fuel combustion are effected in the same manner as the normal engine cycle .
• SC fuel skip cycle
• FIG. 6 is a graph illustrating the results obtained by comparing concentrations of unburned hydrocarbon emissions after conducting the conventional starting operation (0 skip) and the present skipped-starting operations (1 skip) (3 skips) under a condition where a temperature of cooling water is 30°C, similar to the initial (cold) starting of a car.
• a temperature of cooling water is 30°C, similar to the initial (cold) starting of a car.
• FIG. 6 it is to be readily understood that about 1 second after starting represents a transient section where an air-fuel ratio fluctuates markedly, and thereafter, an equivalence ratio decreases gradually from about 1.6 to about 1.4 while experiencing slight fluctuations.
• a concentration of unburned hydrocarbons (HC) exhausted through the exhaust manifold 16 increases, from 1 to 1.5 seconds after starting, to a very high maximum value of 130,000 ppm due to incomplete combustion in the cylinders 11. Thereafter, a concentration of unburned hydrocarbons (HC) decreases to a low minimum level of 10,000 ppm ⁇ 20,000 ppm due to a temperature rise of the inner walls of the cylinders 11 due to continuous operation of the engine 10.
• the fuel skip cycle (SC) according to the present invention is implemented one time (1 skip)
• a concentration of unburned hydrocarbons (HC) exhausted through the exhaust manifold 16 decreases, from 1 to 1.5 seconds after starting, to a level of 10,000 ppm ⁇ 15,000 ppm, and, 2 seconds after starting, a concentration of unburned hydrocarbons (HC) exhibits a value which is lower than that under normal starting conditions .
• FIG. 7 is a graph illustrating the results obtained by comparing concentrations of unburned hydrocarbons emissions after conducting the conventional starting operation (0 skip) and the present skipped-starting operations (1 skip) (3 skips) under a condition where a temperature of cooling water is 50°C, similar to restarting after an idle stop which occurs a short period of time after starting of a car.
• the fuel skip cycle (SC) according to the present invention is implemented one time (1 skip)
• a concentration of unburned hydrocarbons (HC) exhausted through the exhaust manifold 16 is decreased, from 1.2 seconds after starting, to a level of 10,000 ppm, which is significantly lower than that obtained under normal starting conditions.
• the fuel skip cycle (SC) according to the present invention is implemented three times (3 skips)
• a concentration of unburned hydrocarbons (HC) exhausted through the exhaust manifold 16 decreases, from 1.7 seconds after starting, to a level no greater than 10,000 ppm which is significantly lower than that obtained under normal starting conditions .
• FIG. 8 is a graph illustrating the results obtained by comparing concentrations of unburned hydrocarbons emissions after conducting the conventional starting operation (0 skip) and the present skipped-starting operations (1 skip) (3 skips) under a condition where a temperature of cooling water is 70°C, similar to restarting after an idle stop which occurs after traveling through a certain distance following starting a car.
• a temperature of cooling water 70°C
• a concentration of unburned hydrocarbons (HC) exhausted through the exhaust manifold 16 increases, from 1 to 2.5 seconds after starting, to a level of 15,000 ppm ⁇ 30,000 ppm. Thereafter, a concentration of unburned hydrocarbons (HC) decreases to a level of 10,000 ppm ⁇ 17,000 ppm.
• SC fuel skip cycle
• FIG. 9 is a graph illustrating the results obtained by comparing the concentrations of unburned hydrocarbon emissions after conducting the conventional starting operation (0 skip) and the present skipped-starting operations (1 skip) (3 skips) under a condition where a temperature of cooling water is 90°C, similar to restarting after idle stop which occurs when the engine is sufficiently warmed up following starting of a car.
• a temperature of cooling water is 90°C
• a concentration of unburned hydrocarbons (HC) exhausted through the exhaust manifold 16 is increased, from 1 to 3 seconds after starting, to a level of 20,000. ppm ⁇ 30,000 ppm. Thereafter, a concentration of unburned hydrocarbons (HC) decreases to a level of 10,000 ppm ⁇ 17,000 ppm.
• the fuel skip cycle (SC) according to the present invention is implemented one time (1 skip) , it is to be recognized that a concentration of unburned hydrocarbons (HC) exhausted through the exhaust manifold 16 has, from 2 to 3.5 seconds after starting, a level of 10,000 ppm ⁇ 25,000 ppm, as a result of which the unburned hydrocarbon emission-reducing effect is slight when compared to the normal starting condition.
• HC unburned hydrocarbons
• the fuel skip cycle (SC) when the fuel skip cycle (SC) is applied at least one time following the start of a car, it is possible to accomplish an unburned hydrocarbon (HC) emission-reducing effect that is an improvement over a normal start. Also, when simultaneously considering an unburned hydrocarbon (HC) emission-reducing effect and a start delay of a car, it is not preferable to apply the fuel skip cycle (SC) four or more times following the start of a car. As a consequence, it is preferred that the fuel skip cycle (SC) is applied a minimum of one to a maximum of three times following the start of a car.
• results of travel mode tests conducted to demonstrate working effects accomplished by the present invention will be described in detail.
• the travel mode tests were conducted to confirm whether the present invention satisfies the travel test modes for a car, which are regulated in U.S., Europe, Japan, Korea, etc.
• the travel test modes for a car include an FTP72 and an FTP75 of U.S., an ECE/EG of Europe, 11- and 10-modes of Japan, and so forth.
• FTP72 and FTP75 modes of U.S. a test is completed by one cycle, a test distance is 12.1 km, an average speed is 31-34 km/h, and a maximum speed is 91.2 km/h.
• the ECE/EG of- Europe and the 11- and 10-modes of Japan are characterized in that a test cycle is repeated four times for each test.
• a test distance for one cycle is very short, about 1.0 km, an average speed is 18.7 km/h, and a maximum speed is 50 km/h which is less than that of the FTP modes.
• an idle rotation rate is 31%, this mode has the longest idle rotation period among the test modes .
• test distances of one cycle are 1.0 km and 0.7 km, respectively.
• Average speeds are 30.6 km/h and 17.7 km/h, and maximum speeds are 60 km/h and 40 km/h. Idle rotation rates during one test period are 21.7% and 26.7%. Characteristics of these modes are presented in Table 3.
• the above-described FTP75 test cycle designates a representative driving speed pattern of a car, which is measured in morning rush hours at Los Angeles, U.S., and is composed of three test phases .
• a first phase is a cold phase to be tested for 0-505 seconds
• a second phase is a stabilized phase to be tested for 505-1,372 seconds.
• a third phase corresponding to a hot phase is tested for 1,972-2,477 seconds .
• the test for a car is conducted after parking the car in a test room having a temperature of 20 ⁇ 30°C for no less than 12 hours.
• a travel test is conducted in conformity with a regulated travel speed.
• emission (exhaust gas) of the car is collected in a first bag.
• Emission discharged from 505 seconds to 1,371 seconds after the stabilized phase begins is collected in a second bag.
• the third phase proceeds for 505 seconds.
• Exhaust gas discharged at the third phase is collected in a third bag. Since there is a regulation which prohibits the first and second bags from being exposed to the outside for more than 20 minutes, immediately when the second phase is completed, analysis is implemented. Analysis for the exhaust gas collected in the third bag is implemented simultaneously with the completion of the third phase.
• Table 4 indicates allowance limits for exhaust gas of a car by the FTP75 test cycle regulated in U.S. and California.
• Travel characteristics of the CVS 75 mode are employed in Korea. While there is a substantial gap between the CVS 75 mode and a downtown traveling pattern in Korea, the Ministry of Environment of Korea adopted the FTP75 mode regulated in U.S. and applied it to the downtown traveling pattern in Korea.
• the CVS 75 mode is composed of a cold phase of 505 seconds, a stabilized phase of 867 seconds and a hot phase of 505 seconds.
• Cars measured using the CVS 75 test mode include a base car, a car which is fitted with an HC adsorber, and a control mode 1 car which is fitted with an ASG (auto stop and go) system according to the present invention. Measurement results for the respective cars are presented in Table 5.
• the base car, the car fitted with the HC adsorber and the control mode 1 car fitted with the ASG system all satisfy the allowable limits for exhaust gases including CO (of which the allowable limit is ⁇ 2.11 g/km), Nox (of which the allowable limit is ⁇ 0.19 g/kg) and NMHC (of which the allowable limit is ⁇ 0.062 g/km), regulated by the CVS 75 test mode. Therefore, all the cars were shown to be able to be driven in Korea.
• the control mode 1 car fitted with the ASG system has the idle stop function. Therefore, when the car is restarted, fuel injection into two cylinders among four cylinders is skipped for three cycles.
• FIGs. 11 through 16 are graphs which are obtained by comparing the resultant values of Table 5 for respective measurement items .
• CO emission is the most in Phi and is decreased in Ph2
• CO emission is the most in Ph2 and is the least in Phi.
• Characteristics of the control mode 1 car fitted with the ASG are in that, since an engine is interrupted in the idle phase and restarted at a point where the idle phase ends and a speed of the car increases, in order for the ECU to ensure the certainty of start when restarting from the idle stop, an increased amount of fuel is injected so as to supply a dense mixture. At this time, in a catalyst, even when a temperature of the catalyst is sufficiently high, because the catalyst is positioned out of a cleaning region, it is nearly impossible to clean the exhaust gas and reduce the emission of CO. Thus, in the case of the control mode 1 car fitted with the ASG, the emission of CO cannot help but increase when compared to the other cars.
• FIG. 12 is a graph which is obtained by comparing the measurements of NOx for the respective test cars . When viewed as a whole, NOx exhaust is largest in Phi and smallest in Ph2, and all the cars satisfy the allowable NOx emission limit of 0.19 g/km, regulated by the CVS 75.
• FIG. 13 is a graph which is obtained by comparing the measurements of NMHC for the respective test cars. When viewed as a whole, while exhaust of NMHC is largest in Phi and smallest in Ph2, in the case of the car fitted with the ASG, exhaust of NMHC is largest in Ph3.
• NMHC is an exhaust gas which is most related to the warm-up degree of an engine.
• the control mode 1 car fitted with the ASG since the engine is always stopped and restarted in the idle phase, a difference exists in terms of warm-up phase when compared to the other car conditions, to reveal different exhaust emission characteristics .
• All of the cars satisfy the allowable NMHC emission limit of no greater than 0.062 g/km, regulated by the CVS 75.
• FIG. 14 is a graph which is obtained by comparing the measurements of C0 2 for the respective test cars . When viewed as a whole, C0 2 exhaust is largest in Phi and smallest in Ph3. C0 2 is an exhaust gas which is directly related to the fuel economy of an engine.
• FIG. 15 is a graph which is obtained by comparing the measurements of F.E. (fuel economy) and C0 2 for the respective test cars .
• FIG. 16 is a graph illustrating measurements of exhaust gas of the respective test cars, with reference to the allowable limits for exhaust gas of a car, which are regulated in the CVS 75.
• ECE15+EUCE Test Cycle an ECE/EG cycle is to test a driving speed pattern and is prepared on the basis of a driver's driving practice in a downtown.
• the ECE test cycle is adopted in Belgium, Denmark,
• a test cycle begins after starting a car which has been parked for 12 hours in a test room having a temperature of 20 ⁇ 30°C and warming up the car for 40 seconds.
• One cycle is completed by repeating a travel pattern having a test distance of 1.013 km four times.
• exhaust gas is collected in the same sample bag and then, analysis of the exhaust gas is conducted.
• a car test mode has been changed from the ECE/EG mode to the ECE15+EUDC mode.
• the ECE15+EUDC mode a high speed mode is added to the ECE/EG mode to constitute a total test distance of 11 km.
• the ECE15+EUDC mode has been applied as a test mode of an EUR03.
• Table 6 represents allowable emission limits of a car regulated by the ECE/EG test cycle.
• the ECE15+EUDC mode has an idle rotation rate of 31% whereas the CVS 75 mode has an idle rotation rate of 17.9%.
• a first cycle has idle rotation intervals of 11 seconds, 21 seconds and 21 seconds, and second through fourth cycles have idle rotation intervals of 18 seconds, 21 seconds and 21 seconds. Therefore, it was judged that the time at the idle rotation intervals allows exhaust gas to have an idle rotation preventing function and improves fuel economy.
• Table 7 represents car test results according to the ECE15+EUDC mode.
• FIGs. 17 through 22 are graphs comparing the resultant measurements of Table 7 for the respective test items .
• Phi designates a downtown traveling pattern
• Ph2 designates a highway traveling pattern. Resultant measurements of the test cars must be mainly observed in terms of Phi.
• respective measurements are denoted by g/km.
• CO is denoted by 30 g/test
• HC+NOx is denoted by 8 g/test.
• the emission of CO is increased in Phi and decreased in Ph2.
• CO is increased in Ph2 and decreased in Phi .
• Characteristics of the control mode 0 and the control mode 1 cars fitted with the ASG are in that, since an engine is interrupted in an idle phase and restarted at a point where the idle phase ends and a speed of the car is accelerated, in order for the ECU to ensure the certainty of start when restarting from the idle stop, an increased amount of fuel is injected to supply a dense mixture.
• FIG. 18 is a graph which is obtained by comparing the measurements of NOx for the respective test cars. When viewed as a whole, NOx exhaust is largest in Phi and smallest in Ph2.
• FIG. 19 is a graph which is obtained by comparing the measurements of NMHC for the respective test cars. When viewed as a whole, NMHC exhaust is largest in Phi and smallest in Ph2.
• NMHC is most greatly exhausted in the case of the base car at 0.64 g/km.
• NMHC In the case of control mode 0 car fitted with the ASG, NMHC of 0.624 g/km is exhausted.
• control mode 1 car fitted with the ASG In the case of control mode 1 car fitted with the ASG, NMHC of 0.605 g/km is exhausted.
• NMHC of 0.293 g/km is largest.
• ECE15+EUDC mode it is to be readily understood that, since it has an idle phase which is longer than that of the CVS 75 mode, a significant exhaust gas reducing effect can be accomplished due to the idle stop.
• FIG. 20 is a graph which is obtained by comparing the measurements of C0 2 for the respective test cars.
• FIG. 21 is a graph which compares the fuel economy and the measurements of C0 2 for the respective test cars.
• FIG. 22 is a graph illustrating exhaust emission measurements of the respective test cars with reference to the allowable emission limits for a car, which is regulated by ECE15+EUDC.
• the allowable emission limit is 30 g/test
• the base car was 15.82 g/test
• the car fitted with the HC adsorber was 10.72 g/test
• the control mode 1 car fitted with the ASG was 27.29 g/test, by which it is to be readily understood that all test cars sufficiently satisfy the allowable emission limits.
• CO emission was 48.74 g/test, in excess of the allowable emission limit, so that it does not satisfy the regulated value.
• the control mode 0 of the car fitted with the ASG corresponds to the general restart mode in which fuel skip is not implemented when restarting after idle stop in the idle phase.
• the base car was 4.822 g/test
• the car fitted with the HC adsorber was 2.27 g/test
• the control mode 0 of the car fitted with the ASG was 5.75 g/test
• the control mode 1 of the car fitted with the ASG was 5.32 g/test, by which it is to be readily understood that all test cars sufficiently satisfy the allowable emission limits.
• Modal test There is a Modal test in which reliability is slightly lower than the authentication test under the ECE15+EUDC mode but it is possible to analyze an emission degree per hour. In this Modal test, it is possible to measure all exhaust emissions per second in test phases and output the results, so that characteristics of the exhaust emissions generated in the respective driving phases of a travel mode can be analyzed.
• the Modal test was conducted for the base car and control modes 2 and 3 of the car fitted with the ASG, and the results were presented in the following Table 8. In the control mode 2, the idle stop function acts from when a temperature of cooling water is 65°C, and in the control mode 3, fuel injection skip is implemented.
• FIGs. 23 through 29 are graphs comparing the measurements of Table 8 for respective test items.
• the control mode 2 represents a mode in which the ASG function acts when a temperature of cooling water is 65°C, and operates substantially from the third cycle among four cycles constituting Phi in the ECE15+EUDC mode.
• the control mode 3 represents a control mode in which the ASG function acts in the first cycle among four cycles constituting Phi, does not act in the second cycle and acts again in the third cycle.
• FIG. 24 is a graph comparing measurements of NOx for the test cars. It is to be noted that the control mode 2 discharges the least NOx to render NOx emission reducing effect when compared to the base car.
• FIG. 25 is a graph comparing measurements of NMHC for ⁇ the test cars.
• Emission of NMHC has a very important 'meaning.
• the control mode 2 has the least emission of NMHC and therefore accomplishes an NMHC emission reducing effect superior to the base car.
• the emission of NMHC is somewhat increased when compared to the base car.
• the control mode 3 of the car fitted with the ASG is 0.75 g/km which is the most, the base car is 0.595 g/km, and the control mode 2 of the car fitted with the ASG is 0.520 g/km which is the least.
• an NMHC reducing effect of about 12.6% was accomplished.
• FIG. 26 is a graph comparing measurements of C0 2 for the test cars.
• the base car is 282.4 g/km
• the control mode 2 of the car fitted with the ASG is 267.7 g/km
• the control mode 3 of the car fitted with the ASG is 255.1 g/km.
• the control mode 3 of the car fitted with the ASG has the least emission of C0 2 .
• the reason for this is that, since the ECE15+EUDC mode has an idle phase which is longer than that of the CVS 75 mode, a significant exhaust gas reducing effect can be accomplished due to the idle stop.
• FIG. 27 is a graph comparing measurements of fuel economy for the test cars. Referring to FIG.
• FIG. 28 is a graph comparing measurements of fuel economy and C0 2 for the test cars .
• the control mode 2 of the car fitted with the ASG effects were accomplished in that fuel economy is improved by about 2.5%, and C0 2 is reduced by 2.9%, when compared to the base car.
• FIG. 29 is a graph illustrating exhaust emission measurements of the respective test cars with reference to the allowable emission limits for a car, which is regulated by ECE15+EUDC.
• the allowable emission limit is 30 g/test
• the base car was 8.26 g/test
• the control mode 2 of the car fitted with the ASG was 15.19 g/test
• the control mode 3 of the car fitted with the ASG was 23.1 g/test, by which it is to be readily understood that all test cars sufficiently satisfy the allowable emission limits .
• ASG was 5.406, by which it is to be readily understood that all test cars sufficiently satisfy the allowable emission limits .
• the control mode 2 revealed satisfiable results over the base car by 11.1% in NOx, 10.2% in NMHC,

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
• Ignition Installations For Internal Combustion Engines (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=36242004

Family Applications (1)

Country Status (3)

Families Citing this family (6)

Family Cites Families (5)

• 2004
  • 2004-08-24 EP EP04774391A patent/EP1664510A1/en not_active Withdrawn
  • 2004-08-24 WO PCT/KR2004/002130 patent/WO2005019629A1/en active Application Filing
  • 2004-08-24 JP JP2006508544A patent/JP2006526735A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events