JP4000792B2 - Fuel injection control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection control device for an internal combustion engine, and more particularly to a fuel injection control device for an internal combustion engine that can prevent a control for increasing an injection amount from being repeated many times when the internal combustion engine is started for the first time.
[0002]
[Prior art]
Some internal combustion engines mounted on vehicles and the like are provided with a fuel injection valve for injecting fuel. The fuel injection valve is connected to the fuel tank by a fuel pipe. The fuel in the fuel tank is supplied to the fuel injection valve via the fuel pipe by the fuel pump, and is supplied by being injected into the internal combustion engine. The fuel injected by the fuel injection valve is controlled by the fuel injection control device. The fuel injection control device controls the operation of the fuel injection valve so as to inject an injection amount of fuel determined according to the operating state of the internal combustion engine.
[0003]
A vehicle equipped with the internal combustion engine is assembled in an assembly line at a factory, and when the assembly is completed, the internal combustion engine is started and self-runs to make the line off. The fuel piping from the fuel tank immediately after the assembly of the internal combustion engine to the fuel injection valve is not filled with fuel but contains air. Therefore, when the internal combustion engine is started for the first time after assembly, fuel cannot be injected until all the air in the fuel pipe is exhausted, so there is a problem that it takes time from the start to the complete explosion.
[0004]
Examples of shortening the time from the start of the initial start of the internal combustion engine to the complete explosion include those disclosed in Japanese Patent Application Laid-Open Nos. 8-1000069 and 9-317527.
[0005]
Japanese Patent Laid-Open No. 8-100696 discloses that a fuel injection valve is forcibly controlled to open for a predetermined period of time based on a predetermined valve opening time for air injection when power is first applied to a fuel supply control device. It is what you want to do.
[0006]
Japanese Patent Application Laid-Open No. 9-317527 discloses an increase correction of the valve opening time of the fuel injection valve when the internal combustion engine is started and in a non-combustion state.
[0007]
[Problems to be solved by the invention]
By the way, as described above, the fuel injection control device of the internal combustion engine increases the valve opening time when the initial start condition is satisfied in order to shorten the time from the start of the initial start of the internal combustion engine to the complete explosion. I have control. Thereby, the fuel injection control device scavenges the air in the fuel pipe and increases the fuel injection amount by increasing the fuel injection amount until a predetermined time elapses after the starter motor is rotated and cranking is started. When the start of the internal combustion engine is completed due to the complete explosion due to the combustion of fuel, the increase in the injection amount is stopped and returned to the normal injection amount.
[0008]
However, since the conventional fuel injection control device sets that the internal combustion engine has completed a complete explosion as a condition for stopping the increase in the injection amount and returning it to the normal injection amount, a complete explosion is detected. There is a problem that requires detection means.
[0009]
In addition, the conventional fuel injection control device again performs the initial start when the initial start condition is satisfied after the control for increasing the injection amount at the initial start is performed, or when the backup data in the control means is cleared. There is a possibility that control for increasing the injection amount is performed.
[0010]
[Means for Solving the Problems]
Accordingly, in order to eliminate the above-described disadvantages, the present invention is provided with a fuel injection valve that injects fuel into the internal combustion engine, and the fuel injection is performed so as to inject an amount of fuel determined according to the operating state of the internal combustion engine. Fuel injection control means for controlling the operation of the valve is provided, storage means for storing start information on whether the internal combustion engine is started for the first time or after the second time is provided, and at least as an initial start condition when starting the internal combustion engine When the condition that the starting information stored in the storage means is the first start is satisfied, there is provided an initial injection control means for controlling to increase the injection amount, and an integrated value of the increased injection amount by the initial injection control means When the fuel injection pressure exceeds a set value, a decrease injection control means is provided for controlling to gradually decrease the increased injection amount, and an integration of the increased injection amount by the initial injection control means is provided. If a is greater than or equal to the specified value is characterized in that a start information rewriting means for rewriting the startup information in the second and subsequent start-up.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The fuel injection control device for an internal combustion engine according to the present invention controls to increase the injection amount when at least the start information stored in the storage means as the initial start condition at the start of the internal combustion engine satisfies the initial start condition. Thus, when the internal combustion engine is started for the first time, the air in the fuel pipe can be quickly discharged to shorten the time from the start to the complete explosion, and the integrated value of the increased injection amount becomes equal to or greater than the set value. In such a case, by controlling so that the increased injection amount is gradually decreased, the increase in the injection amount can be stopped by calculation and returned to the normal injection amount. There is no need to provide a complete explosion detection means for detection. Further, the internal combustion engine fuel injection control device rewrites the start information of the storage means to the second and subsequent starts when the integrated value of the increased injection amount by the initial injection control means is equal to or greater than the set value, It is possible to prevent the control for increasing the injection amount at the initial start again.
[0012]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention. In FIG. 3, 2 is an internal combustion engine mounted on a vehicle (not shown), 4 is a cylinder block, 6 is a cylinder head, 8 is a head cover, and 10 is a combustion chamber.
[0013]
The internal combustion engine 2 has an intake passage 22 that communicates with the combustion chamber 10 by sequentially connecting an air cleaner 12, an intake pipe 14, a throttle body 16, a surge tank 18, and an intake manifold 20 as an intake system. A throttle valve 24 is provided in the intake passage 22 of the throttle body 16. Further, the internal combustion engine 2 is provided with an exhaust passage 32 that sequentially connects an exhaust manifold 26, an exhaust pipe 28, and a catalytic converter 30 as an exhaust system and communicates with the combustion chamber 10.
[0014]
The internal combustion engine 2 is provided with a supercharger 34 that supercharges intake air. The supercharger 34 is provided with a compressor 36 in the middle of the intake pipe 14, and a turbine 38 that drives the compressor 36 in the middle of the exhaust pipe 28. In the internal combustion engine 2, an intercooler 40 is provided in the intake pipe 14 on the downstream side of the compressor 36.
[0015]
The supercharger 34 is provided with a bypass passage 42 that bypasses the turbine 38 and communicates with the exhaust passage 32, a waste gate valve 44 that opens and closes the bypass passage 42, and an actuator 46 that opens and closes the waste gate valve 44. ing. The actuator 46 opens and closes the waste gate valve 44 by the supercharging pressure introduced from the intake passage 22 on the downstream side of the compressor 36 to control the supercharging pressure to the set supercharging pressure.
[0016]
The internal combustion engine 2 is provided with an ignition coil 46 attached to the head cover 8. Further, the internal combustion engine 2 is provided with a first blow-by gas passage 50 that communicates the inside of the head cover 8 and the intake passage 22 of the surge tank 18 via the PCV valve 48, and the intake passage 22 directly downstream of the air cleaner 12 and the air cleaner 12 is provided. Is provided with a second blow-by gas passage 52.
[0017]
In the internal combustion engine 2, the intake manifold 20 is provided with a fuel injection valve 54 that injects fuel toward each combustion chamber 10. The fuel injection valve 54 is connected to the fuel tank 60 by a fuel supply passage 58 via a fuel distribution pipe 56. A fuel filter 62 is provided in the fuel supply passage 58. A fuel pump 64 is provided in the fuel tank 60.
[0018]
The fuel in the fuel tank 60 is pumped to the fuel supply passage 58 by the fuel pump 64, dust is removed by the fuel filter 62, the pressure is adjusted by the fuel pressure adjusting unit 66, and the fuel distribution pipe 56 is used for each combustion chamber 10. The fuel injection valve 54 is distributed and supplied. Excess fuel whose pressure has been adjusted by the fuel pressure adjusting unit 66 is returned to the fuel tank 60 by the fuel return passage 68.
[0019]
The fuel tank 60 communicates with one end side of an evaporation passage 72 having a two-way check valve 70 interposed therebetween. The other end side of the evaporation passage 72 communicates with the canister 74. The canister 74 communicates with one end of a purge passage 78 having a one-way check valve 76 interposed therebetween. The other end side of the purge passage 78 communicates with the intake passage 22 of the throttle body 16.
[0020]
The internal combustion engine 2 is provided with an idle air passage 80 that bypasses the throttle valve 24 and communicates the intake passage 22 of the throttle body 16 and the intake passage 22 of the surge tank 18. In the middle of the idle air passage 80, an idle air amount control valve 82 for adjusting the idle air amount is provided.
[0021]
The internal combustion engine 2 is provided with a crank angle sensor 84 for detecting the crank angle for detecting the engine speed, and a throttle opening sensor 86 for detecting the throttle opening of the throttle valve 24 to detect knocking. The sensor 88 is provided, the intake air temperature sensor 90 for detecting the intake air temperature is provided, the cooling water temperature sensor 92 for detecting the cooling water temperature is provided, the pressure sensor 94 for detecting the pressure of the intake air as the supercharging pressure is provided, An O2 sensor 96 for detecting the oxygen concentration is provided.
[0022]
The ignition coil 46, fuel injection valve 54, fuel pump 64, idle air amount control valve 82, crank angle sensor 84, throttle opening sensor 86, knocking sensor 88, intake air temperature sensor 90, cooling water temperature sensor 92, and pressure sensor 94. And the O2 sensor 96 are connected to the control unit 100 constituting the fuel injection control device 98.
[0023]
An ignition switch 102 of the internal combustion engine 2 is connected to the control unit 100, and a battery 108 is connected via a main switch 104 and a fuse 106. The control unit 100 controls the operation of the ignition coil 46, the fuel injection valve 54, and the like by signals input from the crank sensor 84 to the O2 sensor 96, and controls the ignition timing and the injection amount.
[0024]
The fuel injection control device 98 is provided with fuel injection control means 110, storage means 112, initial injection control means 114, decrease injection control means 116, and start information rewriting means 118 in the control unit 100.
[0025]
The fuel injection control means 110 controls the operation of the fuel injection valve 54 so as to inject an amount of fuel determined according to the operating state of the internal combustion engine 2. The storage means 112 stores start information on whether the internal combustion engine 2 is started for the first time or after the second time. The storage means 112 is composed of a flash memory (an electrically rewritable nonvolatile semiconductor memory).
[0026]
The initial injection control means 114 controls to increase the injection amount when at least the start information stored in the storage means 112 is satisfied as the initial start condition when the internal combustion engine 2 is started. . In this embodiment, the initial injection control means 114 is in the temperature range where the start information stored in the storage means 112 is the initial start and the coolant temperature exceeds the lower limit temperature and the upper limit temperature as the initial start conditions. If the condition is satisfied, control is performed to increase the injection amount.
[0027]
When the integrated value of the increased injection amount by the initial injection control unit 114 becomes equal to or greater than a set value, the decreased injection control unit 116 controls to gradually decrease the increased injection amount. The set value is the volume of the fuel distribution pipe 56, the fuel supply passage 58, the fuel filter 62, the fuel pressure adjustment section 66, the fuel return passage 68, etc. that constitute the fuel pipe disposed from the fuel tank 60 to the fuel injection valve 54. Set by.
[0028]
The start information rewriting means 118 rewrites the start information stored in the storage means 112 to the second and subsequent start when the integrated value of the increased injection amount by the initial injection control means 114 becomes equal to or greater than the set value. The start information rewriting means 118 calculates a set time calculated from the time required from the start of cranking of the internal combustion engine 2 until the integrated value of the increased injection amount by the initial injection control means 114 becomes equal to or greater than the set value. When either one of the condition exceeding the above condition and the condition where the ignition switch 102 is turned OFF after the start of the internal combustion engine 2 is satisfied, the start information in the storage means 112 is rewritten to the second and subsequent start.
[0029]
Next, the operation of this embodiment will be described with reference to FIGS.
[0030]
As shown in FIG. 1, when the ignition switch 102 is turned on and the control starts (200), the fuel injection control device 98 is in a clear state: Tf = '0'. It is determined whether or not there is (202), and it is determined whether or not the condition that the start information stored in the storage means 112 as the initial start condition is the first start is satisfied.
[0031]
If this determination (202) is NO, the routine jumps to (216) to end the increase in the injection amount TP. If this determination (202) is YES, it is determined whether or not the cooling water temperature TWN exceeds the lower limit temperature TWPL and is lower than or equal to the upper limit temperature TWPH (204), and the cooling water temperature falls within the set temperature range as the initial start condition. It is determined whether or not a certain condition is satisfied.
[0032]
If this determination (204) is NO, the process jumps to (216) to end the increase in the injection amount TP. When this determination (204) is YES, the basic injection amount TPBASE is multiplied by the initial start increase correction KPURG (TP = TPBASE * KPURG) to increase the obtained injection amount TP (206), as shown in FIG. The increased injection amount TP is integrated {TPs = TPi + (TPi−1)} to obtain an integrated value TPs (208), and it is determined whether or not the integrated value TPs is equal to or greater than the set value TPc (TPs ≧ TPc). (210).
[0033]
If this determination (210) is NO, the processing returns to the processing (206). If this determination (210) is YES, as shown in FIG. 2, the increased injection amount TP is gradually decreased (212), and a flag of Tf = '1' is set in the flash memory as the storage means 112. (214) The starting information stored in the storage means 112 is rewritten to the second and subsequent startings, and the increase in the injection amount TP is terminated (216).
[0034]
It should be noted that the integrated value TPs of the injection quantity TP increased by the initial injection control means 114 from the start of cranking of the internal combustion engine 2 is set at a timing when the start information stored in the storage means 112 is rewritten to the second or subsequent start. A condition in which a calculation time TSs calculated from a time TTPc required to reach TPc or more (TTPc * FT) exceeds a set time TSc, and a condition in which the ignition switch 102 is turned off after the start of the internal combustion engine 2 is completed. It is assumed that either one is true.
[0035]
The condition that the calculated time TSs exceeds the set time TSc (TSs> TSc) is that the time FT times the time TTPc required until the integrated value TPs of the increased injection amount TP becomes equal to or greater than the set value TPc has elapsed. Thus, the state in which the internal combustion engine 2 is stably operated is determined. The condition that the ignition switch 102 is turned off after the start of the internal combustion engine 2 is completed is to determine a state in which the internal combustion engine 2 is stopped after being stably operated.
[0036]
Thus, as shown in FIG. 2, the fuel injection control device 98 of the internal combustion engine 2 has a condition that at least the start information stored in the storage means 112 as the initial start condition when the internal combustion engine 2 is started is the first start. When established, the control is performed to increase the injection amount TP, so that the air in the fuel pipe such as the fuel supply passage 58 is quickly discharged at the initial start of the internal combustion engine 2 to shorten the time from the start to the complete explosion. When the integrated value TPs of the increased injection amount TP becomes equal to or greater than the set value TPc, the increase in the injection amount TP is calculated by performing control so as to gradually decrease the increased injection amount TP. Since it is possible to stop and return to the normal injection amount, it is not necessary to provide a complete explosion detecting means for detecting that the internal combustion engine 2 has completely exploded as in the prior art. Can.
[0037]
Further, the fuel injection control device 98 of the internal combustion engine 2 gives the starting information of the storage means 112 for the second and subsequent times when the integrated value TPs of the injection amount TP increased by the initial injection control means 114 becomes equal to or greater than the set value TPc. It is possible to prevent the control to increase the injection amount of the initial start again.
[0038]
Therefore, the fuel injection control device 98 of the internal combustion engine 2 can prevent the control for increasing the injection amount from being repeated many times when the internal combustion engine 2 is started for the first time, thereby improving the reliability of the control. Can do.
[0039]
Further, the fuel injection control device 98 of the internal combustion engine 2 is provided with a flash memory as the storage means 112, so that even when the backup data is cleared, control for increasing the initial start injection amount is performed again. The reliability of control can be improved.
[0040]
In the above-described embodiment, when the initial start condition is satisfied, the injection amount TP obtained by TPBASE * KPURG is increased, and the integrated value TPs of the increased injection amount TP is equal to or greater than the set value TPc (TPs ≧ TPc). ), The increased injection amount TP is gradually decreased. However, the injection amount TP can be increased or decreased by the crank angle.
[0041]
For example, as shown in FIG. 2, the injection amount TP is multiplied by PRV (TP * PRV) from the cranking start to the crank angle determination, and after the crank angle determination, the injection amount TP every N rotations of the crankshaft. Is gradually decreased to PRV2 times (TP * PRV2), and thereafter, the injection amount TP is maintained at PRV2 times (TP * PRV2), thereby increasing / decreasing according to the crank angle.
[0042]
In the above-described embodiment, the injection amount TP increased by multiplying a certain value when the initial start condition is satisfied is set to a constant value. However, the initial injection amount TP is set to the maximum value, and then the injection amount TP. Is set so as to decrease in a quadratic curve, the air in the fuel pipe can be discharged more quickly, and the time from the start to the complete explosion can be shortened.
[0043]
Further, in the above-described embodiment, when the integrated value TPs of the increased injection amount TP becomes equal to or greater than the set value TPc, the first start injection is again performed by rewriting the start information in the storage means 112 to the second and subsequent start. Although the control to increase the amount is prevented, when the starting information in the storage means 112 is rewritten to the second and subsequent startings, the fuel is removed from the fuel pipe due to the disassembly / maintenance of the fuel system. When the fuel has run out from the fuel pipe due to lack of gas, a control is provided to increase the injection amount of the initial start again by providing means for rewriting the start information of the storage means 112 from the second start to the initial start. It is possible to reduce the time from the start of the first start to the complete explosion after maintenance.
[0044]
Furthermore, in the above-described embodiment, the air in the fuel pipe such as the fuel supply passage 58 is ejected from the fuel injection valve 54 to the intake passage 22 and discharged. It is also possible to provide a discharge valve that is opened and to discharge air, and when the integrated value TPs of the injection amount TP increased at the initial start of the internal combustion engine 2 becomes equal to or greater than the set value TPc, the air pressure is increased. Although the injection amount TP is controlled so as to gradually decrease, it is also possible to perform control so as to switch to normal fuel injection when the injection of air from the fuel injection valve 54 ends and liquid fuel is injected.
[0045]
【The invention's effect】
Thus, the fuel injection control device for an internal combustion engine according to the present invention can quickly discharge the air in the fuel pipe when the internal combustion engine is started for the first time, thereby reducing the time from the start to the complete explosion. The increase in the injection amount can be stopped and returned to the normal injection amount, and there is no need to provide a complete explosion detection means for detecting that the internal combustion engine has completed a complete explosion as in the prior art. Further, the fuel injection control device for the internal combustion engine is not performed again after the control for increasing the injection amount at the initial start is performed.
[0046]
For this reason, the fuel injection control device for the internal combustion engine can prevent the control for increasing the injection amount from being repeated many times when the internal combustion engine is first started, and can improve the reliability of the control.
[Brief description of the drawings]
FIG. 1 is a flowchart of control of a fuel injection control device showing an embodiment of the present invention.
FIG. 2 is a control timing chart of the fuel injection control device.
FIG. 3 is a schematic configuration diagram of an internal combustion engine provided with a fuel injection control device.
[Explanation of symbols]
2 Internal combustion engine 10 Combustion chamber 22 Intake passage 32 Exhaust passage 34 Supercharger 54 Fuel injection valve 84 Crank angle sensor 86 Throttle opening sensor 88 Knock sensor 90 Intake temperature sensor 92 Cooling water temperature sensor 94 Vehicle speed sensor 94 Pressure sensor 96 O2 sensor 98 Fuel Injection Control Device 100 Control Unit 102 Ignition Switch 110 Fuel Injection Control Unit 112 Storage Unit 114 Initial Injection Control Unit 116 Decrease Injection Control Unit 118 Start Information Rewriting Unit

Claims (3)

A fuel injection valve for injecting fuel into the internal combustion engine; and a fuel injection control means for controlling the operation of the fuel injection valve so as to inject an amount of fuel determined according to an operating state of the internal combustion engine. Storage means for storing start information indicating whether the engine is started for the first time or after the second time is provided, and at least the start information stored in the storage means as the initial start condition when starting the internal combustion engine is the first start. When a certain condition is satisfied, an initial injection control means for controlling the injection amount to be increased is provided, and when the integrated value of the increased injection amount by the initial injection control means exceeds a set value, the increased injection A decrease injection control means for controlling the amount to gradually decrease is provided, and when the integrated value of the increased injection amount by the initial injection control means becomes a set value or more, the start information is given for the second time. Providing the start information rewriting means for rewriting the descending of starting fuel injection control device for an internal combustion engine characterized by. The start information rewriting means has a set time calculated from the time required from the start of cranking of the internal combustion engine until the integrated value of the increased injection amount by the initial injection control means exceeds a set value. When either one of the exceeded condition and the condition where the ignition switch is turned off after the start of the internal combustion engine is satisfied, the start information rewriting means for rewriting the start information of the storage means to the second and subsequent start The fuel injection control device for an internal combustion engine according to claim 1, wherein the fuel injection control device is provided. 3. The fuel injection control apparatus for an internal combustion engine according to claim 1, wherein the storage means is a flash memory.

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