ES2325060T3 - METHOD AND APPLIANCE FOR DETERMINING A QUANTITY OF FUEL SUPPLY OF AN INTERNAL COMBUSTION ENGINE. - Google Patents

Abstract

Method for determining the amount of fuel supplied to an internal combustion engine (1) which has the stages of fixing a first ratio, which reflects the correlation between engine speed (NE) and the amount of fuel supply, setting a speed of the target engine for idling (NETRG) based on the load acting on the engine (1) and obtaining a final fuel supply quantity (QFIN), using the final fuel supply quantity (QFIN) to drive the engine (1 ) at the target motor speed (NETRG), characterized by: the additional stage of setting a second relationship, which reflects the correlation between the motor speed (NE) and the friction created in the motor (1), obtaining the amount of Final fuel supply (QFIN) using the first relationship and the second relationship.

Description

Method and apparatus for determining a quantity of Fuel supply of an internal combustion engine.

The present invention relates to a method and an apparatus for determining a quantity of fuel supply  in an internal combustion engine. In particular, this invention relates to a method and an apparatus for determining the amount of fuel supply for a combustion engine internal idling.

In a diesel engine for a vehicle of the Japanese patent publication open for public inspection 11-141380, the amount of fuel injection It is determined according to the engine running state during idle.  Likewise, an integral correction factor is calculated based on the difference between the actual idle speed and a speed of target engine during idle (one idle speed objective). The integral correction factor is used to correct the amount of fuel injection. When the load is increased of the engine, for example, by turning on the air conditioner, the fuel injection amount is corrected to respond to a Estimated increase in engine load. Also, since the target idle speed increases as load increases of the engine, it is necessary to change the amount of fuel injection Therefore, an amount of Supplementary fuel injection correction. The amount of supplementary correction is used to change the amount of fuel injection by a corresponding amount with changes in speed at idle speed. As a result, the idle speed is controlled to respond to the increase in load.

A typical vehicle includes not only an air conditioning but also other auxiliary devices that they drive through the engine. The load applied to the engine for each auxiliary device varies according to the type of device. The Target idle speed varies depending on the load applied to the engine. When engine speed changes, engine friction is that is, the load that acts on the engine changes.

Therefore, it is necessary to determine the data used to obtain the additional correction amount for each type of auxiliary engine device considering the quantity of change in the amount of fuel injection that corresponds to changes in target idle speed and also changes in motor friction, which corresponds to the real idle speed However, determine the data for each type of auxiliary engine device considering the engine friction is extremely problematic and therefore complicated the development of programs to control the injection control of fuel. Also, if the engine specifications are changed, the degree of changes applied to the correction amount Supplementary is changed. Therefore, each time the engine specifications, the data must be determined for calculate the amount of supplementary correction for each type of auxiliary devices through experiments. In this way, Program developments are complicated, and the cost increases

In the technique presented in the publication earlier, if the engine speed changes sharply, it turns out uncomfortable for passengers. Therefore, when turned on any of the auxiliary devices of the engine, the amount of Supplementary correction is not added to the injection amount of current fuel once but it is added to the amount of Current fuel injection gradually. However, such gradual change procedure requires that the amount of supplementary correction and target idle speed will gradually change synchronously. Make a program to directly change the amount of supplementary correction of gradually complicates programs and procedures to Control the amount of fuel injection.

In this way, the control procedure of the idle speed of the prior art requires processes complicated to develop programs. That is, develop the programs to calculate the amount of fuel injection for a required idle speed increases the costs of engine development

EP 0 547 650 discloses a method and idle speed control apparatus that controls the idle speed depending on the target motor output.

Therefore, an object of the present invention is to provide a method and an apparatus for determining the fuel injection amount of a combustion engine internal that simplifies programs to calculate the amount of fuel injection for a required idle speed, thereby reducing the costs to develop the engine.

To achieve the above and other objectives and according to the purpose of the present invention, a method is provided to determine the amount of fuel supplied to an engine Internal combustion The method includes setting a first ratio, which reflects the correlation between engine speed and the amount of fuel supply, set a second ratio, which reflects the correlation between engine speed and the friction created in the engine, set an engine speed target for idle based on the load acting on the engine, and get a final fuel supply amount using the first relationship and the second relationship, using the amount of final fuel supply to drive the engine to target engine speed

The present invention has also tested a apparatus for determining the amount of fuel supplied to An internal combustion engine. The device includes means for store first relationship data and second relationship data, means for setting a target engine speed for idling based on the load acting on the engine, and means for calculate a final fuel supply amount using the First relationship data and second relationship data. The data First relationship reflect the correlation between the speed of the engine and the amount of fuel supply. The data from second relationship reflect the correlation between the speed of the engine and friction created in the engine. The supply amount of  final fuel is used to drive the engine at the speed of target engine

Other aspects and advantages of the invention will be evident from the following description, taken in conjunction with the accompanying drawings, which illustrate by way of example The principles of the invention.

The invention, together with the objects and advantages of it, can be better understood by reference to the following description of the currently preferred embodiments together with the attached drawings in which:

Figure 1 is a schematic view illustrating a common rail diesel engine and a control system according to a first embodiment of the present invention;

Figure 2 is a flow chart showing a routine to control the amount of fuel injection executed by the electronic control unit shown in the figure one;

Figure 3 is a graph showing a correlation used in the routine of figure 2 to calculate basic injection amounts tQGOV1 and tQGOV2 based on the NE engine speed and the degree to which the pedal is depressed ACCP acceleration;

Figure 4 is a flow chart showing a routine to control a speed control procedure at idle (ISC) executed by the electronic control unit shown in figure 1;

Figure 5 is a flow chart showing a routine to calculate an estimate correction factor of ISC executed by the electronic control unit shown in the Figure 1;

Figures 6 (A), 6 (B), and 6 (C) are correlations used in the routine of the figure 5;

Figures 7 (A) and 7 (B) are correlations used in the routine of Figure 5;

Figure 8 is a flow chart showing a part of a routine for an ISC procedure executed by an ECU according to a second embodiment;

Figure 9 is a schedule showing a example of the procedure according to the second embodiment; Y

Figure 10 is a schedule showing a procedure according to a modification of the second embodiment.

Figure 1 is a schematic view illustrating an accumulator type diesel engine (a common rail type diesel engine) 1 and its control system according to a first embodiment of the present invention. Diesel engine 1 is an internal combustion engine used in a vehicle.

Engine 1 has four cylinders # 1, # 2, # 3, and # 4 (only one is shown in figure 1). An injector 2 is located in the combustion chamber of each of the cylinders # 1 to # 4. Each injector 2 is connected to an electromagnetic valve. The amount of fuel injection from each injector 2 in the Corresponding cylinders # 1 to # 4 are controlled by a corresponding electromagnetic valve 3.

Each injector 2 is connected to a pressure accumulator, which is a common rail 4 in this embodiment. While the solenoid valve 3 is open, the fuel in the common rail 4 is injected from each injector 2 into the corresponding # 1- # 4 cylinder. The common rail 4 maintains a relatively high pressure that corresponds to the fuel injection pressure. To maintain such a high pressure, the common rail 4 is connected to a discharge orifice 6a of a supply pump 6 through a supply pipe 5. A check valve 7 is located in the supply pipe 5. The valve Withdrawal 7 allows the fuel to be supplied from the supply pump 6 to the common rail 4 and prevents the fuel from flowing from the common rail 4 to the supply pump 6.

The supply pump 6 is connected to a fuel tank 8 through a suction hole 6b. A filter 9 is located between the fuel tank 8 and the suction hole 6b. The supply pump 6 sucks fuel from the fuel tank 8 through the filter 9. The supply pump 6 includes a plunger and a cam. The cam is operated in synchronization with the motor 1 and makes the piston oscillate. The piston increases the fuel pressure to a required level and then sends pressurized fuel to the common rail 4.

A pressure control valve 10 is located in the vicinity of the discharge orifice 6a of the supply pump 6. The pressure control valve 10 controls the injection pressure, or the fuel pressure supplied from the discharge orifice 6a to the common rail 4. When the control valve 10 is open, the fuel that has not been discharged from the discharge orifice 6a, or the excess fuel, is returned to the fuel tank 8 through a return orifice 6c of the supply pump 6 and a return line 11.

Each combustion chamber is connected to a common intake duct 13 and a common exhaust duct 14. Each combustion chamber is selectively connected to and disconnected from the intake duct 13 by means of a valve intake 31. Also, each combustion chamber is connected selectively with and disconnected from the exhaust duct 14 by means of a corresponding exhaust valve 32. Valves admission 31 are driven by an intake camshaft (no shown), and the exhaust valves 32 are operated by a exhaust camshaft (not shown). The camshafts are coupled to a crankshaft (not shown) of engine 1 through a timing belt and turn at half the speed of rotation of the crankshaft.

An incandescent spark plug 18 is located in each combustion chamber. Each glow plug 18 is connected to an incandescent relay 18a. Each glow plug 18 receives current from the corresponding incandescent relay 18a and set incandescent immediately before starting engine 1.

Atomized fuel is sprayed on the incandescent spark plug 18 in an incandescent state, which favors ignition and combustion. In this way, the glow plugs 18 function as an auxiliary device to start the engine 1.

Engine 1 has the following sensors to detect the running state of the engine 1. A pedal sensor acceleration 20 is located in the vicinity of a pedal acceleration 19. Pedal sensor 20 detects the degree to which press the ACCP acceleration pedal 19. A closing switch complete 21 is arranged near the acceleration pedal sensor 20. Full close switch 21 turns on when the pedal of acceleration 19 has not been depressed and emits a closing signal full.

An air flow sensor 22 is located in the intake duct 13. The air flow sensor 22 detects the air inlet flow in the intake duct 13, or the GN amount of air intake sucked into the chamber of combustion. A coolant temperature sensor 24 is located in the engine cylinder block 1. The sensor coolant temperature 24 detects the THW temperature of the refrigerant.

A fuel temperature sensor 26 is located in the return line 11 to detect the fuel temperature. A fuel pressure sensor 27 is located in the common rail 4 to detect the PC pressure of the fuel in the common rail 4.

A crankshaft rotor (not shown) is attached to the engine crankshaft 1. The crankshaft rotor has protrusions circumferential A crankshaft sensor 28 is located in the proximity of the crankshaft rotor. The crankshaft sensor 28 detects the projections on the crankshaft rotor and emits signals from impulse. A cam rotor (not shown) is attached to one of the shaft of intake cams and the exhaust camshaft. The rotor of Cam has circumferential protrusions. A cam sensor 29 is located in the vicinity of the cam rotor. The cam sensor 29 detects the projections on the cam rotor and emits signals from impulse. The speed of rotation of the crankshaft, or the speed of the NE engine, and the angle of rotation of the crankshaft, or the angle of the crankshaft  AC are calculated based on impulse signals. It also estimate that the piston in each cylinder # 1- # 4 is in neutral upper (TDC) based on impulse signals.

A vehicle speed sensor 30 is located in the vicinity of the output shaft of a transmission (no shown). The vehicle speed sensor 30 detects the SPD vehicle speed based on the rotation speed of the output tree

The vehicle also has an air switch conditioning 34, a power steering switch 36, and a alternator control circuit 38. The air switch conditioning 34 is used to turn an air on and off conditioning, which is driven by the engine 1. The vehicle has a power steering system, which is operated by pressure Hydraulics generated by a motor driven hydraulic pump 1. The power steering switch 36 emits a signal that represents if the power steering system is working. He alternator control circuit 38 is located in an alternator and controls the generation of electricity by the alternator through of service signal control.

The various engine control procedures 1 are executed by an electronic control unit (ECU) 40. ECU 40 executes procedures to control the amount of fuel injection The ECU 40 includes a central unit of process (CPU), a read-only memory (ROM) to store various programs, correlations and data, an access memory random (RAM) to temporarily store results of CPU calculation, a backup RAM to make a copy of reservation of necessary data, a timer-counter, an input interface, and an output interface, which are connected to each other through a bus

The acceleration pedal sensor 20, the sensor air flow 22, coolant temperature sensor 34, a fuel temperature sensor 26, the pressure sensor of fuel 27 and alternator control circuit 38 are connected to the input interface through a memory corresponding intermediate, a common multiplexer, and a common analog-to-digital converter (none of the which is shown), respectively. The crankshaft sensor 28, the cam sensor 29, and vehicle speed sensor 30 are connected to the input interface through a circuit corresponding waveform conformation (not shown), respectively. The complete closing switch 21, the switch air conditioner 34 and power steering switch 36 They are directly connected to the input interface. CPU receives signals from the sensors through the interface of entry.

The electromagnetic valve 3, the valve pressure control 10, and incandescent relay 18a are connected to the output interface through a drive circuit. The CPU executes control calculations based on the received signals and controls the solenoid valve 3, the control valve of pressure 10, and the incandescent relay 18a.

A procedure of fuel injection quantity control, which runs through ECU 40, with reference to a flow chart of the figure 2. The procedure in figure 2 is executed in a manner interrupted at each injection. Since motor 1 is of the type of four cylinders, the procedure is executed in each of the 180º increments of the crankshaft angle. Each stage of procedure is represented by a letter "S" accompanied of a number

When the procedure starts, ECU 40 stores various information in the RAM work area in the step S110. Stored information includes engine speed NE detected by the sensor of NE 28, the degree to which the ACCP acceleration pedal detected by the pedal sensor acceleration 20, an integral correction factor QII, a factor of QIPB estimated load correction of speed control at idle (ISC), and a rotation speed correction factor Dear QIPB of ISC. The integral correction factor QII, the ISC QIPB estimated load correction factor, and the ISC QIPB estimated rotational speed correction are calculated in an ISC control procedure, which will be analyzed later.

In step S120, ECU 40 calculates an amount Basic idle injection tQGOV1 and an injection amount basic moving vehicle tQGOV2 referring to a correlation shown in figure 3. The correlation of figure 3 defines the ratio of the basic injection quantities tQGOV1, tQGOV2 with the speed of the NE motor and the degree to which the ACCP acceleration pedal. As shown in the correlation of Figure 3, the amount of basic idle injection tQGOV1 is shown by dashed lines and corresponds to a low speed range of motor 1, that is, with the state at idle or a state close to idle state. The amount of Basic injection of moving vehicle tQGOV2 shown by continuous lines and corresponds to a high interval engine speed 1, that is, with a state in which the Vehicle is in motion.

In step S130, ECU 40 adds the factor of integral correction QII, the estimated load correction factor ISC QIPB, and the estimated rotation speed correction factor ISC QIPB to the basic idle injection amount tQGOV1, and add the ISC QIPB estimated load correction factor to the basic injection amount of moving vehicle tQGOV2. The ECU 40 compares the sums and sets the largest as an amount of QGOV corrected injection. Therefore, as shown in the Figure 3, when the speed of the NE motor is relatively low, the corrected injection quantity QGOV of engine 1 is calculated in its most adding values to the basic injection amount of I idle tQGOV1. When engine speed is relatively high, the amount of corrected injection QGOV is calculated in your most adding values to the basic injection amount of tQGOV2 moving vehicle.

In step S140, ECU 40 calculates an amount Maximum injection QFULL. The maximum injection quantity QFULL is the upper limit value of the amount of fuel injected in combustion chambers, and is determined to suppress a abrupt increase in smoke from combustion chambers and to prevent excessive torque.

In step S150, the ECU 40 sets the lowest of the maximum injection quantity QFULL and injection quantity corrected QGOV as a final injection quantity QFIN. In the step S160, ECU 40 calculates a TSP injection period, which is corresponds to the amount of final injection QFIN. On stage S170, ECU 40 issues the TSP injection period, and then Temporarily suspend the current routine. Each valve Electromagnetic 3 is controlled based on the injection period TSP. Then the corresponding injector 2 injects fuel whose amount corresponds to the amount of final injection QFIN.

Figure 4 shows a flow chart of a Idle speed control procedure (ISC). He procedure of figure 4 is executed in an interrupted manner in Each injection

When the procedure starts, ECU 40 stores various information in the work area of a RAM in the step S210. The information stored includes the degree to which press the ACCP acceleration pedal detected by the pedal sensor 20, the on-off state of the switch full shutdown 21, THW refrigerant temperature detected by the coolant temperature sensor 24, the speed of the NE motor detected by sensor NE 28, the speed of the SPD vehicle detected by vehicle speed sensor 30, the on-off state of the air switch conditioning 34, the on-off state of the power steering switch 36, and a service relationship of DU alternator control generated by the control circuit of alternator 38.

In step S220, the ECU 40 estimates whether motor 1 It is currently idling. For example, if the degree to which you step on The ACCP acceleration pedal is 0%, the closing switch Complete 21 is on, and the SPD vehicle speed is 0km / h, ECU 40 estimates that engine 1 is idling.

If engine 1 is not idling, or if the result of step S220 is negative, ECU 40 suspends so  Temporary current routine.

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If engine 1 is idling, or if the result from step S220 is positive, ECU 40 continues until stage S230 In step S230, the ECU 40 sets an idle speed NETRG goal that is appropriate for the state on-off air conditioner, status power steering system on-off,  the electric charge represented by the DU service ratio, and THW refrigerant temperature. ECU 40 determines the NETRG target idle speed based on correlations and data stored in the ROM. For example, idle speed NETRG target is set relatively high if the air conditioner is on, the power steering system is on, the Electric charge is high, and THW coolant temperature is low.

In step S240, ECU 40 calculates the NEDL difference between the NETRG target idle speed and the Actual NE motor speed through the following formula 1.

[Formula 1] NEDL \ leftarrow NETRG - NE

In step S250, ECU 40 calculates an amount integral ΔQII based on the NEDL difference by reference to a map stored in ROM. If the difference NEDL has a positive value, the integral amount ΔQII is set to a positive value, and if the NEDL difference has a value negative, the integral amount ΔQII is set to a value negative.

In step S260, ECU 40 adds the amount integral ΔQII of the current control cycle to a factor of integral correction QII (i-1) of the quantity fuel injection calculated in the control cycle previous. ECU 40 sets the resulting as the correction factor integral QII (i) current.

In step S270, the ECU 40 executes a procedure for a calculation of a correction factor of ISC estimation. When step S270 is completed, ECU 40 Temporarily suspend the current routine.

Figure 5 is a flow chart showing ISC estimate correction factor calculation. In the step S310 of this procedure, ECU 40 calculates the factor of ISC QIPB estimated rotation speed correction of amount of fuel injection based on an Fx function of the following formula 2

[Formula 2] QIPNT \ leftarrow Ax * (NETRG - NETRGbs)

The symbol Ax represents the gradient of the basic injection amount tQGOV1 or tQGOV2 when the degree to which the ACCP acceleration pedal is pressed is 0% in the correlation of Figure 3. In other words, the value Ax represents the relationship of the basic injection quantity tQGOV1 or tQGOV2 with the speed of the NE motor when motor 1 receives no load. If the Corrected injection amount QGOV is set based on the basic idle injection quantity tQGOV1 in step S130 of Figure 2, the Ax value corresponding to the amount of basic idle injection tQGOV1 is used in formula 2. If the Corrected injection amount QGOV is set based on the basic injection amount of moving vehicle tQGOV2 in the step S130 of Figure 2, the Ax value corresponding to the basic injection amount of moving vehicle tQGOV2 se use in formula 2. The NETRGbs symbol is an idle speed referential and represents the lowest idle speed, which is use when no load is applied to motor 1 and it has been completed engine warming 1.

The rotation speed correction factor QIPNT represents the amount of fuel shortage or excess of fuel created due to idle speed changes NETRG objective in the calculation using the correlation of Figure 3. In other words, the rotation speed correction factor QIPNT corresponds to the amount of a change in the amount of fuel injection that needs to be done according to a change in idle speed NETRG target.

In step S320, the ECU 40 calculates a factor of QIPBB friction correction based on NE motor speed real referring to a correlation shown in the figure 6 (A). The correlation in Figure 6 (A) represents the relationship between the engine speed NE and the friction generated in the motor 1. The friction in the motor 1 changes according to the speed of the NE motor The friction correction factor QIPBB is used to reflect friction changes according to NE motor speed in the amount of fuel injection.

In step S330, the ECU 40 calculates a factor of QIPBCL low temperature correction based on temperature THW refrigerant referring to a correlation shown in figure 6 (B). The friction in the motor 1 changes according to the THW refrigerant temperature, which reflects the temperature of the engine. Specifically, when engine 1 is cold, the friction increases. The low temperature correction factor QIPBCL It is used to reflect changes in friction according to temperature of the THW refrigerant in the injection amount of fuel.

In step S340, the ECU 40 calculates a factor of QIPBDF electric charge correction based on the ratio of DU service referring to a correlation shown in the Figure 6 (C). The vehicle includes various devices that they consume electricity such as 18 glow plugs and headlights. The alternator control circuit 38 adjusts the ratio of DU control service, which is sent to the alternator, to increase the  alternator electricity generation according to an increase in electricity used by such devices. Correction factor QIPBDF electric charge is used to reflect changes in the DU service control ratio, which reflects the consumption of electricity by devices that consume electricity, in the amount of fuel injection.

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In step S350, the ECU 40 estimates whether the air Conditioning is working. If the air conditioner is working, or if the result of step S350 is positive, the ECU 40 continues to step S360. In step S360, the ECU 40 Calculate a QIPBAC air conditioning correction factor based on the actual NE motor speed referring to a correlation of figure 7 (A). The correction factor of QIPBAC air conditioner is used to reflect engine load due to the operation of the air conditioner in the amount of fuel injection and adjusts according to engine speed NE.

If the air conditioner is not working, or if the result of step S350 is negative, ECU 40 continues until step S370. In step S370, the ECU 40 sets the factor of QIPBAC air conditioning correction to zero.

In step S380, the ECU 40 estimates whether the system Power steering is working. If the steering system assisted is working, or if the result of step S380 is positive, ECU 40 continues to step S390. In step S390, ECU 40 calculates a power steering correction factor QIPBPS based on the actual NE motor speed doing reference to a correlation of figure 7 (B). The factor of power steering correction QIPBPS is used to reflect the engine load due to steering system operation assisted in the amount of fuel injection and adjusts according to the speed of the NE motor.

If the power steering system is not running, or if the result of step S380 is negative, the ECU 40 continues to step S400. In step S400, the ECU 40 sets the QIPBPS power steering correction factor at zero.

In step S410, ECU 40 calculates the sum of the friction correction factor QIPBB, the correction factor of QIPBCL cold start, the electric charge correction factor QIPBDF, the QIPBAC air conditioning correction factor, and the QIPBPS power steering correction factor. ECU 40 sets the resulting as the load correction factor QIPB.

The rotation speed correction factor QIPNT and the load correction factor QIPB are calculated from the manner described above and are reflected in the amount of corrected injection QGOV, which is calculated in step S130 of the fuel injection quantity control procedure (figure 2). Therefore, the amount of injection corrected QGOV it is determined so that the engine speed NE searches for the NETRG target idle speed, which corresponds to various loads acting on the motor 1.

The first embodiment has the following advantages.

(A) The AX value, which represents the relationship between the engine speed NE and the amount of basic injection tQGOV1, tQGOV2, is used to calculate the correction factor of QIPNT rotation speed. The speed correction factor of QIPNT turn corresponds to the amount of a change in the amount of fuel injection that needs to be done according to A change in idle speed NETRG target. The correlation of Figure 6 (A) is used to calculate the factor of QIPBB friction correction based on NE motor speed.  The friction correction factor QIPBB is used to reflect engine friction changes based on NE engine speed actual in the amount of fuel injection. The correlation of Figure 6 (A) is stored independently in the ROM of the ECU 40 from the Ax value and the correlations to obtain correction factors apart from the correction factor of QIPBB friction.

The auxiliary devices of the engine, or external charging devices, such as air conditioning and the power steering system is powered by the power of the motor 1 and apply load to motor 1. The load applied to motor 1 It varies according to the type of each auxiliary device. Speed to NETRG target idle is determined based on the load acting on the engine 1. The amount of fuel injection is controlled by so that the actual NE motor speed looks for idle speed NETRG determined objective. When the NE motor speed changes actual, therefore, the friction in the engine 1 is changed. therefore, it is necessary to correct the injection amount of fuel according to changes in engine friction.

However, as described previously, the amount of a change in the amount of injection of fuel that needs to be made according to a change in the NETRG target idle speed is corrected by the factor of QIPNT rotation speed correction. In addition, a change in the engine friction caused by a change in the speed of the Actual NE engine is corrected by adjusting the injection amount of fuel using the friction correction factor QIPBB. He QIPBB friction correction factor is calculated so independent of the other correction factors QIPNT, QIPBCL, QIPBDF, QIPBAC, QIPBPS. Specifically, the factor of QIPBB friction correction is calculated using the correlation of the Figure 6 (A), which is specially designed to calculate the friction correction factor QIPBB. Therefore doing reference to the correlation of figure 6 (A), the factor of QIPBB friction correction is easily determined based on only at the actual NE motor speed. It is not necessary determine the data to obtain a correction value of fuel injection that corresponds to the friction of the engine for each type of auxiliary engine device. Likewise, QIPNT rotation speed correction factor is calculated easily based on the idle speed NETRG target referring to formula 2. As a result, the factors of correction are easily calculated based on changes in speed to NETRG target idle.

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As described above, it is not it is necessary to determine the data to obtain a correction value fuel injection that corresponds to the speed at NETRG target idle for each of the auxiliary devices the motor. This facilitates the development of programs to Control fuel injection.

Since the Ax value is included in the design of the program, it is only necessary to obtain the correlation of the Figure 6 (A) to calculate the friction correction factor QIPBB through experiments when the specification is changed of the engine 1. In other words, it is not necessary to determine the data to calculate the amount of fuel injection correction for each type of auxiliary engine device, which reduces the development costs

When speed changes to target idle NETRG, the rotation speed correction factor QIPNT is changed automatically through step S310 of figure 5. By consequently, the actual NE motor speed is changed, and, through of step S320, the factor of QIPBB friction correction. Thus, a calculation is not necessary to adjust the friction correction factor QIPBB to follow changes in idle speed NETRG target. Therefore, The program is simplified.

Therefore, the program is simplified to calculate the amount of fuel injection to drive the Engine 1 at a required idle speed. This simplifies the development of programs to control the amount of injection made out of fuel. Consequently, the development cost of the engine 1 is reduced.

(B) The air correction factor QIPBAC conditioning, the power steering correction factor QIPBPS, the cold start correction factor QIPBCL, and the QIPBDF electric charge correction factor are calculated by separated with respect to the speed correction factor QIPNT and the friction correction factor QIPBB. The factors of QIPBAC, QIPBPS, QIPBCL, and QIPBDF correction are calculated according to the NE engine speed, THW coolant temperature and DU service relationship. Therefore, the amount of injection of fuel to adjust the idle speed so that it corresponds to the loads that act on the motor 1 is calculated reliably

A second one is described below. embodiment of the present invention. Instead of step S230 of ISC control procedure (figure 4) of the first embodiment, a procedure of figure 8 is executed in the second embodiment Other structures are the same as in the First realization

If the result of step S220 of Figure 4 is positive, ECU 40 continues to step S510 of Figure 8. In step S510, the ECU 40 determines an idle speed tNETRG referential objective that corresponds to the state on-off air conditioner, status on-off steering system assisted, the electric charge represented by the ratio of DU service of the alternator control, and the temperature of the THW refrigerant

In step S520, ECU 40 estimates whether the cycle Current control is the first after starting engine 1. Yes the current cycle is the first, or if the result of step S520 is positive, ECU 40 continues to step S530. In step S530, ECU 40 initializes the NETRG target idle speed with the idle speed reference target tNETRG. Yes routine current is not the first, or if the result of step S520 is negative, the ECU 40 maintains the idle speed NETRG target current.

In step S540, ECU 40 estimates whether the formula 3 is fulfilled.

[Formula 3] NETRG + dNE < tNETRG

The symbol dNE represents a margin of change gradual and is determined so that a change in the speed of the NE motor due to an increase in target idle speed NETRG is not a nuisance to passengers.

When step S540 is executed the first time, that is, when the process moves from step S530 to the stage S540, the NETRG is equal to tNETRG. Thus, formula 3 is not met, and The result of step S540 is negative. Therefore, the ECU 40 Continue to step S550 and estimate if formula 4 is met.

[Formula 4] NETRG - dNE> tNETRG

When step S550 is executed the first time, that is, when the process moves from step S530 to the stage S540, NETRG is equal to tNETRG. Thus, formula 4 is not met, or the result of step S550 is negative. In this case, ECU 40 Continue to step S560. In step S560, the ECU 40 replaces idle speed reference target tNETRG for speed to NETRG target idle and then continue to the stage S240 of Figure 4. In steps S240 of Figure 4 and S310 of the Figure 5 below, the NETRG target idle speed, which is equal to the idle speed reference target tNETRG, it is used to calculate the NEDL difference and the correction factor of QIPNT rotation speed.

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Next, the case is described in which the current execution of the control cycle takes place a second or more time since the engine 1 is started, that is, the case when step S530 is not executed. If the difference between the tNETRG target idle speed, which is calculated in step S510, and the current NETRG target idle speed is less than the gradual change margin dNE, the results of steps S540 and S550 are negative. In this case, ECU 40 continues to step S560. In step S560, the ECU 40 sets the target idle speed tNETRG, which was calculated in the current cycle, as a new target idle speed value.
NETRG

If, for example, the air is turned on conditioned in this state, the load acting on the  engine 1. Then, idle speed reference target tNETRG, which is calculated in step S510, becomes significantly higher than the idle speed value tNETRG reference objective that was calculated in the control cycle previous, that is, that the current idle speed value NETRG objective.

If the idle speed reference target tNETRG exceeds the sum of the idle speed NETRG target current and the gradual margin of change dNE, formula 3 is met and The result of step S540 is positive. In this case, ECU 40 Continue to step S570 and calculate the idle speed NETRG objective through the following formula 5.

[Formula 5] NETRG \ leftarrow NETRG + dNE

That is, the idle speed NETRG target it is increased by the gradual margin of change dNE.

In later stages S240, S310, the speed at NETRG target idle, which is calculated by adding the margin of gradual change dNE to idle speed NETRG target from from the previous control cycle, it is used to calculate the difference NEDL and the rotation speed correction factor QIPNT.

If formula 3 is met in the procedure of subsequent control, or if the result of step S540 is positive, ECU 40 continues to step S570 and increases the speed to NETRG target idle through the gradual exchange margin dNE a through formula 5.

In this way, the target idle speed NETRG is gradually increased until formula 3 is not met, or until the result of step S540 is negative. If he result of step S540 was positive in the control cycle previous and negative in the current control cycle, the difference between the current NETRG target idle speed and the speed at idle target current tNETRG target is equal to or less than gradual margin of change dNE. In this case, the result of the stage Later S550 is negative. Therefore, ECU 40 continues up to step S560 and set the target idle speed Referential tNETRG as the idle speed NETRG target. By therefore, in the subsequent stages S240, S310, the speed at NETRG target idle, which is set to idle speed tNETRG reference objective, is used to calculate the difference NEDL and the rotation speed correction factor QIPNT.

From then on, the idle speed tNETRG benchmark continues to be used as the speed at NETRG target idle as long as the target idle speed Referential tNETRG is not changed to exceed the exchange margin gradual dNE.

If the air conditioning is turned off, the formula NETRG - dNE> tNETRG is met. In this case, formula 4 is complies and the result of step S550 is positive. Therefore, the ECU 40 calculates the NETRG target idle speed through the following formula 6.

[Formula 6] NETRG \ leftarrow NETRG - dNE

The NETRG target idle speed is decreases through the gradual margin of change dNE.

In the subsequent steps S240, S310, the NETRG target idle speed, which is calculated by subtracting the gradual change margin dNE of target idle speed NETRG of the previous control cycle, is used to calculate the NEDL difference and the rotation speed correction factor QIPNT

If formula 4 is met in the control cycle later, or if the result of step S550 is positive, the ECU 40 continues to step S580 and slows down NETRG objective through the gradual exchange margin dNE through the formula 6.

In this way, the target idle speed NETRG gradually decreases until formula 4 is not meets, or until the result of step S550 is negative. If he result of step S550 was positive in the control cycle previous and negative in the current control cycle, the difference between the current NETRG target idle speed and the speed at idle target current tNETRG target is equal to or less than gradual margin of change dNE. In this case, the ECU 40 sets the idle speed reference target tNETRG as the speed at NETRG target idle at step S560 later. Therefore in the subsequent stages S240, S310, the target idle speed NETRG, which is set at idle speed reference target tNETRG, is used to calculate the NEDL difference and the factor of QIPNT rotation speed correction.

From then on, the idle speed tNETRG benchmark continues to be used as the speed at NETRG target idle as long as the target idle speed Referential tNETRG is not changed to exceed the exchange margin gradual dNE.

An example of the following is described procedure according to the second embodiment with reference to schedule of figure 9. When the air switch conditioning 34 turns on at time t0, the speed at idle target tNETRG is set to a value that represents the load due to the air conditioner. However, the NETRG target idle speed is gradually increased to the idle speed tNETRG reference target in a period from time t0 to time t1. Like idle speed NETRG goal is gradually changed, the correction factor of QIPNT rotation speed is changed gradually. As the factor of QIPNT rotation speed correction is gradually changed, the Actual NE engine speed is gradually changed. As the Actual NE motor speed is gradually changed, the factor of QIPBB friction correction, the air correction factor QIPBAC conditioning, and the estimated load correction factor ISC QIPB are gradually changed.

Therefore, it is not necessary to control directly the friction correction factor QIPBB for change it gradually. That is, when the idle speed NETRG goal is directly controlled to change gradually, the friction correction factor QIPBB follows automatically changes in idle speed NETRG target. Also, the Actual NE engine speed is gradually changed.

When the air conditioner switch 34 is turn off as shown in figure 9 (time t2 to time t3), the control values related to the control of the amount of fuel injection are changed in the same way as when the air conditioning switch 34 turns on. Also, when the power steering system turns on or off, the control values related to the control of the amount of fuel injection are changed in the same way as when the air conditioning switch 34 turns on or off.

In addition to the advantages of the first embodiment, the second embodiment has the following advantages.

(A) As shown in the procedure of calculation of an ISC estimation correction factor of the Figure 5, the rotation speed correction factor is changed QIPNT by simply changing the speed to idle NETRG target. Consequently, the actual NE motor speed is changed, and the friction correction factor QIPBB, the correction factor of QIPBAC air conditioner, and address correction factor Assisted QIPBPS are changed.

When changing the load acting on the Engine 1, NETRG target idle speed is changed gradually according to the engine load so that the speed at target idle NETRG looks for target idle speed Referential tNETRG. Therefore, correction factors QIPNT, QIPBB, QIPBAC, QIPBPS are changed to correspond with the NETRG target idle speed.

Therefore, when the speed is changed to NETRG target idle, NE motor speed is prevented change abruptly, which prevents inconvenience to passengers. Likewise, such a precise procedure is carried out without procedures to control the correction factors QIPNT, QIPBB, QIPBAC, and QIPBPS according to the target idle speed NETRG This simplifies the program and reduces the costs of developing.

It must be evident to experts in the technique that the present invention can be performed from many others specific forms without departing from the scope of the invention. In In particular, it should be understood that the invention can be carried out in The following ways.

In the illustrated embodiment, the factor of QIPBB friction correction, the air correction factor QIPBAC conditioning, and address correction factor QIPBPS assisted are calculated using the actual NE engine speed as a parameter in the correlations. However, the factors of QIPBB, QIPBAC, and QIPBPS correction can be calculated using the NETRG target idle speed as a parameter in them correlations In this case, if the target idle speed NETRG is gradually changed as in the second embodiment, the values change as in the schedule in figure 10.

In the illustrated embodiment, the engine is used diesel type accumulator 1. However, other types may be used Diesel engine For example, the present invention can be applied to a series fuel injection system and to a system of distributor type injection.

Therefore, the present examples and realizations should be considered as illustrative and not restrictive  and the invention should not be limited to the details given in the This document, but can be modified within the scope and equivalence of the appended claims.

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The amount of a change in the amount of fuel injection that needs to be done according to a change in the target idle speed NETRG is corrected by the QIPNT rotation speed correction factor. When friction of the motor is changed due to a change in the engine speed NE actual, the fuel injection amount is adjusted using a QIPBB friction correction factor. The correction factor of QIPBB friction is obtained independently from the other correction factors and using a correlation especially designed. Therefore, all correction factors are calculated easily according to changes in idle speed NETRG target, which facilitates the development of programs to control the fuel injection

Claims (20)

1. Method to determine the amount of fuel supplied to an internal combustion engine (1) that has the stages of set a first relationship, which reflects the correlation between engine speed (NE) and the amount of Fuel supply, set a target motor speed to idle (NETRG) based on the load acting on the motor (1) Y get a supply amount of final fuel (QFIN), using the supply amount of final fuel (QFIN) to drive the engine (1) at speed of the target engine (NETRG), characterized by: the additional stage of setting a second ratio, which reflects the correlation between engine speed (NE) and the friction created in the engine (1), obtaining the supply amount of final fuel (QFIN) using the first ratio and the second relationship. 2. Method according to claim 1, characterized in that the first relationship represents the correlation between engine speed (NE) and the amount of fuel supply in a state in which the engine is not receiving any load. Method according to claim 1, characterized in that the first relation represents the correlation between engine speed (NE) and the amount of fuel supply in a state in which the engine (1) is idling and receives no load. . Method according to any one of claims 1 to 3, characterized by obtaining a first fuel correction factor using the first ratio and based on the difference between the current target engine speed (NETRG) and a reference engine speed (tNETRG ), which is required when the engine (1) is not receiving any load, in which the first fuel correction factor is used to calculate the final fuel supply amount (QFIN). 5. Method according to any one of claims 1 to 3, characterized by obtaining a first fuel correction factor using the first ratio and based on the current target engine speed (NETRG), wherein the first fuel correction factor It is used to calculate the final fuel supply quantity (QFIN). Method according to any one of claims 1 to 5, characterized in that the second relationship defines the relationship between engine speed (NE) and a second fuel correction factor, which corresponds to engine friction, further comprising the method of obtaining the second fuel correction factor based on the actual engine speed (NE) or the target engine speed (NETRG) and using the second ratio, and in which the second fuel correction factor is used to calculate the final fuel supply quantity (QFIN). Method according to any one of claims 1 to 6, characterized by obtaining a third fuel correction factor, which corresponds to an external loading device driven by the engine (1), wherein the third correction factor of Fuel is used to calculate the final fuel supply quantity (QFIN). Method according to claim 7, characterized in that the third fuel correction factor is changed according to the actual engine speed (NE) or the target engine speed (NETRG). 9. Method according to any one of claims 1 to 3, characterized by: get a supply amount of basic fuel (tQGOV1, tQGOV2), which the engine (1) requires during idle; get a first correction factor of fuel using the first ratio, in which the first factor fuel correction corresponds to the amount of a change in the amount of fuel supply according to a change in the target engine speed (NETRG); get a second correction factor of fuel using the second ratio, the second corresponding  fuel correction factor with engine friction; get a third correction factor of fuel, which corresponds to an external charging device motor driven (1); Y correct the supply amount of basic fuel (tQGOV1, tQGOV2) according to correction factors  of fuel first to third, thereby obtaining the final fuel supply quantity (QFIN). Method according to claim 9, characterized in that the first fuel correction factor is obtained based on the target engine speed (NETRG) and using the first ratio, the second fuel correction factor is obtained based on the engine speed. (NE) real and using the second ratio, and in which the third fuel correction factor is changed according to the actual engine speed (NE). Method according to claim 9, characterized in that the first fuel correction factor is obtained based on the target engine speed (NETRG) and using the first ratio, the second fuel correction factor is obtained based on the engine speed. target (NETRG) and using the second ratio, and in which the third fuel correction factor is changed according to the target engine speed (NETRG). 12. Method according to any one of claims 1 to 11, characterized in that the target motor speed (NETRG) is gradually changed to approach a value that is suitable for the load acting on the motor (1). 13. Method for determining the amount of fuel supplied to an internal combustion engine according to claim 1, characterized by: get a supply amount of basic fuel for idling (tQGOV1, tQGOV2) based on the motor speed (NE); get a first correction factor of fuel using the first relationship, which reflects the correlation between engine speed (NE) and supply quantity of basic fuel (tQGOV1, tQGOV2), in which the first factor of fuel correction corresponds to the amount of a change in the amount of fuel supply according to a change in the target engine speed (NETRG); get a second correction factor of fuel using the second ratio, the second corresponding  fuel correction factor with engine friction; Y correct the supply amount of basic fuel (tQGOV1, tQGOV2) according to correction factors  of first and second fuel, thereby obtaining the final fuel supply quantity (QFIN). 14. Apparatus for determining the amount of fuel supplied to an internal combustion engine that has means for storing first relationship data, which reflect the correlation between engine speed (NE) and the amount of Fuel supply, means to set a motor speed idle target (NETRG) based on the load acting on the engine (1), and means for calculating an amount of final fuel supply (QFIN), using the amount of final fuel supply (QFIN) to drive the engine (1) at the target engine speed (NETRG), being characterized by: means for storing second relationship data, that reflect the correlation between engine speed (NE) and the friction created in the engine; and because the means to calculate the amount of final fuel supply (QFIN) use the first data ratio and second relationship data to calculate the amount of final fuel supply (QFIN). 15. Apparatus according to claim 14, characterized in that the calculation means obtain a first fuel correction factor using the first relation data and based on the difference between the current target engine speed (NETRG) and a reference engine speed ( tNETRG), which is required when the engine (1) is not receiving any load, in which the calculation means use the first fuel correction factor to calculate the final fuel supply amount (QFIN). 16. Apparatus according to claim 14 or 15, characterized in that the storage means stores the relationship between engine speed (NE) and a second fuel correction factor, which corresponds to engine friction, such as second data ratio, in which the calculation means obtain the second fuel correction factor based on the actual engine speed (NE) or the target engine speed (NETRG) and using the second relationship data, and in which the media Calculation uses the second fuel correction factor to calculate the final fuel supply quantity (QFIN). 17. Apparatus according to any one of claims 14 to 16, characterized in that the calculation means obtain a third fuel correction factor, which corresponds to an external loading device driven by the engine (1), wherein the means Calculation uses the third fuel correction factor to calculate the final fuel supply amount (QFIN). 18. Apparatus according to claim 17, characterized in that the storage means stores data of a third relation, representing the relationship between engine speed (NE) and the third fuel correction factor, and in which the calculation means they obtain the third fuel correction factor based on the actual engine speed (NE) or target engine speed (NETRG) and using the third relationship data. 19. Apparatus according to any one of claims 14 to 18, characterized in that the fixing means gradually change the speed of the target motor (NETRG) to approach a value that is suitable for the load acting on the motor (1). 20. Apparatus according to any one of claims 14 to 19, characterized in that the engine (1) is a diesel engine.