JP2006274969A - Start injection controller of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To promote the atomization of a fuel and increase startability even during starting at low and extremely low temperatures. <P>SOLUTION: This start injection controller of an engine comprises an engine water temperature detection means, an engine speed detection means, and an injection control means jetting a fuel injection amount by splitting it into multiple times during starting according to an engine water temperature. The number of split jetting times is set larger as the engine water temperature is lower by adding a function to controllably set to the number of times increasing in integral multiple of the quantity of all cylinders of the engine to the injection control means. Furthermore, a relation in interval time between a first injection amount and a second injection amount in the start injection controller of the engine is given by adding a function to controllably set the interval time shorter as the engine water temperature is lower to the injection control means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine start-up injection control device, and more particularly to a fuel injection control for a four-cycle direct injection gasoline engine or a fuel injection control for a port injection engine. TECHNICAL FIELD The present invention relates to an engine start-time injection control device that promotes optimization and improves startability.

  The engine is provided with an engine water temperature detecting means capable of detecting the engine water temperature, and an engine speed detecting means capable of detecting the engine speed, and according to the engine water temperature detected by the engine water temperature detecting means. Some have provided a start-up injection control device provided with injection control means for dividing and injecting a fuel injection amount into a plurality of times.

Japanese Patent No. 3518366 JP-A-4-183948 JP 2000-73823 A

  By the way, a conventional engine includes a direct injection engine that injects a required amount of fuel once in one process from an extremely low temperature to a complete warming when the injector is driven at the time of starting.

  In this direct injection engine, when performing fuel injection in one step, the time required for injection becomes shorter than that of the port injection engine by directly injecting the fuel into the cylinder, and there is a disadvantage that the fuel is difficult to atomize.

  In addition, when the atomization of the fuel is lowered, the fuel is in a droplet state, and when the fuel in the droplet state adheres to the cylinder wall or the upper part of the piston, the combustion deteriorates and the generation of soot is increased. .

  Therefore, in order to eliminate the above disadvantages, the present invention provides an engine water temperature detecting means capable of detecting the engine water temperature, an engine speed detecting means capable of detecting the engine speed, and an engine detected by the engine water temperature detecting means. In the engine start-up injection control device including the injection control means for dividing and injecting the fuel injection amount at start-up according to the water temperature, the number of divisions is set to be higher as the engine water temperature is lower, A function of controlling the number of injections by split injection to be set to a number that increases at an integral multiple of the total number of cylinders of the engine is provided in addition to the injection control means.

  Further, the engine water temperature detecting means capable of detecting the engine water temperature, the engine speed detecting means capable of detecting the engine speed, and the fuel injection amount at start-up according to the engine water temperature detected by the engine water temperature detecting means. In an engine start-up injection control device that includes an injection control means that injects fuel into two parts, the relationship between the interval times of the first injection amount and the second injection amount is such that the lower the engine water temperature, the shorter the interval time. The control function is provided in addition to the injection control means.

  As described above in detail, according to the present invention, the engine water temperature detecting means capable of detecting the engine water temperature, the engine speed detecting means capable of detecting the engine speed, and the engine water temperature detected by the engine water temperature detecting means. Accordingly, in an engine start-up injection control device comprising an injection control means for dividing and injecting a fuel injection amount at start-up into a plurality of times, the number of divisions is set to be larger as the engine water temperature is lower and divided injection is performed. Because the injection control means is added to the injection control means to control the number of injections by an integer multiple of the total number of cylinders in the engine. And startability can be improved, and wrinkles can be reduced.

  Further, an engine water temperature detecting means capable of detecting the engine water temperature, an engine speed detecting means capable of detecting the engine speed, and a fuel injection amount at start-up according to the engine water temperature detected by the engine water temperature detecting means. In an engine start-up injection control device having an injection control means for dividing and injecting, the relationship between the first injection amount, the second injection amount, and the interval time is controlled so that the interval time is set shorter as the engine water temperature is lower. Since this function is provided in addition to the injection control means, the startability at a low temperature can be improved even in the two-split injection.

  By inventing as described above, the number of divisions is set to be higher as the engine water temperature is lower by the injection control means, and the number of injections by the divided injection is set to a number that is increased by an integral multiple of the total number of cylinders of the engine. Control is performed to promote atomization of the fuel, improve startability, and reduce soot even at low temperature and cryogenic start.

  Further, the relationship between the first injection amount and the second injection amount is controlled by the injection control means so that the interval time is set to be shorter as the engine water temperature is lower. Has improved.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  1 to 9 show an embodiment of the present invention. In FIG. 5, 2 is a direct injection gasoline engine mounted on a vehicle (not shown), 4 is a cylinder block, 6 is a cylinder head, 8 is a cylinder head cover, and 10 is a combustion chamber.

  In the intake system, an air cleaner 12, an intake pipe 14 that guides intake air from the air cleaner 12 to the engine 2, a throttle body 16, and an intake manifold 20 integrated with a surge tank 18 are sequentially connected to the engine 2. An intake passage 22 communicating with 10 is formed.

  A throttle valve 24 is provided in the throttle body 16.

  Further, in the exhaust system, an exhaust manifold 32 that guides exhaust from the engine 2, an exhaust pipe 28, and a catalytic converter 30 are sequentially connected, and an exhaust passage 32 that communicates with the combustion chamber 10 is formed.

  Further, the engine 2 is provided with a supercharger (turbocharger) 34 for supercharging intake air from the air cleaner 12. The supercharger 34 includes a compressor 36 provided in the middle of the intake pipe 14 and a turbine 38 provided in the middle of the exhaust pipe 28 to drive the compressor 36, and the compressor 36 and the turbine 38 are connected by a turbo shaft 40. A bypass passage 42 is provided so as to connect the exhaust pipe 28 on the upstream side of the turbine 38 and the exhaust pipe 28 on the downstream side so as to bypass the turbine 38.

  An intercooler 44 for cooling the intake air supercharged by the supercharger 34 is provided in the middle of the intake pipe 14 on the downstream side of the compressor 36.

  The cylinder head 6 is provided with a fuel injection valve 46 that directly injects gasoline as fuel into the combustion chamber 10. The fuel injection valve 46 communicates with the fuel tank 50 through a fuel supply passage 48 that is a fuel pipe. A fuel filter 52 is provided in the middle of the fuel supply passage 48.

  Further, an electromagnetic fuel pump 54 is provided in the fuel tank 50. The fuel in the fuel tank 50 is pumped to the fuel supply passage 48 by the operation of the electromagnetic fuel pump 54, dust is removed by the fuel filter 52, and is fed to the fuel injection valve 46. The fuel is directly injected from the valve 46 into the combustion chamber 10.

  One end side of the regulator passage 56 is connected to the fuel supply passage 48 between the fuel filter 52 and the fuel injection valve 46 via a pressure regulator 58 that adjusts the fuel pressure. The other end side of the regulator passage 56 is disposed in the fuel tank 50.

  The fuel tank 50 communicates with one end side of an evaporation passage 62 having a two-way check valve 60 interposed therebetween. The other end side of the evaporation passage 62 communicates with the canister 64. The canister 64 communicates with one end side of a purge passage 68 provided with a one-way check valve 66. The other end side of the purge passage 68 communicates with the throttle body 16.

  An idle air passage 70 is provided so as to bypass the throttle valve 24 and communicate the inside of the throttle body 16 and the surge tank 18. An ISC valve (also referred to as “idle speed control valve” or “idle air amount control valve”) 72 for adjusting the amount of idle air is provided in the middle of the idle air passage 70.

  Further, an ignition coil 74 and a PCV valve 76 are attached to the cylinder head cover 8. A first blow-by gas passage 78 communicating with the inside of the surge tank 18 is connected to the PCV valve 76. A second blow-by gas passage 80 is provided so that the inside of the cylinder head cover 8 communicates with the intake passage 22 immediately downstream of the air cleaner 12.

  Further, in the engine 2, an engine speed detecting means capable of detecting the engine speed, for example, a crank angle sensor 82 for detecting a crank angle so as to detect the engine speed, and a throttle opening degree of the throttle valve 24 are detected. A throttle sensor 84 for detecting knocking, a knocking sensor 86 for detecting knocking, an intake air temperature sensor 88 for detecting the temperature of intake air, a water temperature sensor 90 for detecting engine water temperature, and a water temperature sensor 90 for detecting engine water temperature. A pressure sensor 92 that detects the pressure of the intake air supercharged by the supercharger 34 as a supercharging pressure, and an O2 sensor 94 that detects the oxygen concentration in the exhaust gas are provided.

  The fuel injection valve 46, the electromagnetic fuel pump 54, the ISC valve 72, the ignition coil 74, the crank angle sensor 82, the throttle sensor 84, the knocking sensor 86, the intake air temperature sensor 88, the water temperature sensor 90, the pressure sensor 92, and the O2 sensor 94. Is in contact with control means 96 (also referred to as “engine control module”). Further, the battery 102 communicates with the control means 96 through the main switch 98 and the fuse 100.

  This control means 96 includes, for example, an injection control means 104 that divides and injects the fuel injection amount at the start into a plurality of times according to the engine water temperature detected by the water temperature sensor 90 that is the engine water temperature detection means. In this injection control means 104, the number of divisions is set to be higher as the engine water temperature is lower, and the number of injections by the divided injection is controlled to be set to a number that increases by an integral multiple of the total number of cylinders of the engine 2. The configuration.

  More specifically, the injection control means 104 can be provided in the control means 96 as a part of the control means 96. However, the injection control means 104 may not be incorporated in the control means 96 and may be in an external connection state. Is possible.

  The “integer multiple” means N times when N = 1, 2, 3,.

  Further, as with the injection control unit 104, the control unit 96 includes a cumulative divided injection number counting unit 106 that counts the number of injections by divided injection from the start of start, and whether or not the engine 2 has completely started. Start completion means 108 for determining the engine 2, and split injection is started, and the engine speed detected by the crank angle sensor 82, which is the engine speed detection means, determines that the engine 2 has been started by the start completion means 108. Even when the operation is performed, the engine operates to inject the starting injection amount until the cumulative number of divided injections counted by the cumulative divided injection number counting means 106 reaches the number of injections by the next set divided injection. is there.

  Further, when the fuel injection amount at the start is divided into two by the injection control means 104, the relationship between the interval time between the first injection amount and the second injection amount is such that the lower the engine water temperature, the longer the interval time. A function of controlling to shorten the time is added and provided.

  In other words, in this embodiment, the start injection is divided injection, so that the effect of improving startability at extremely low temperatures and reducing soot is obtained. Control is performed by switching between multi-split injection and two-split injection with the number of times set, and multi-split injection is performed in the low temperature region, and normal or split fuel injection is performed in the normal temperature region.

  Then, as shown in FIG. 7, in multi-split injection, the delay in starting injection, the number of injections, and the injection interval can be set, and in split injection, the injection start delay, the injection interval, and the injection ratio (first injection amount and second injection). Set the ratio to the amount.

Usually, before all cylinders of the N cylinders explode, the rotation rises and shifts to start-up injection.
Injection cylinder = N
As one set,
Injection cylinder = N-1
Even when the complete explosion determination rotational speed is exceeded, split injection is performed for the last one cylinder.

  For example, when the injection cylinder at the time of exceeding the complete explosion determination rotation is “N−1”, the remaining one cylinder is divided and when the injection cylinder is “N + 1”, the remaining N-1 cylinder is divided and injected. .

In the case of three cylinders, as shown in FIG. 6, when the ignition order is # 1, # 3, # 2, and when the injection starts from # 1, the complete explosion determination is made in # 1, # 3 If the remaining # 2 cylinders are also subjected to start-up injection or start-time split injection, and the # 1 cylinder, # 3 cylinder, # 2 cylinder, and # 1 cylinder have determined complete explosion, the remaining # 3 cylinder, # 3 Two cylinders are injected at start-up or split at start-up.
That is, even if a complete explosion determination is made, there is a case where the injection control is not immediately performed after starting.
Therefore, injection at the time of starting is performed by setting each cylinder once as one set.
However, if the rotation rises quickly and exceeds a certain value, the division is stopped and normal start-up injection is performed.

  When the temperature is low, atomization is promoted and the startability is improved by injecting the required amount once rather than once. Atomization is improved, fuel adhesion to the cylinder wall surface and piston head surface is reduced, and soot generation is also suppressed. Increase the number of divided injections as much as possible. In the two-split injection, when the ratio of the first injection amount is large, the injection interval is lengthened, and when the ratio of the first injection amount is small, the injection interval is shortened. When the temperature is low due to the engine water temperature at the time of starting, the startability is stabilized by shortening the injection interval.

  Next, the operation will be described.

  The injection method selection in FIG. 1 will be described. When the injection method selection program starts (202), the process proceeds to water temperature determination I (204).

  In this water temperature determination I (204), it is determined whether or not to perform split injection. When split injection is performed in this water temperature determination I (204), the process proceeds to water temperature determination II (206). When the split injection is not performed in the water temperature determination I (204), the process proceeds to the normal injection (208).

  In the water temperature determination II (206), a low temperature or normal temperature determination is performed. When the water temperature determination II (206) is a low temperature determination, the process proceeds to multi-split injection (210), and the water temperature determination II is performed. When (206) is normal temperature determination, the process proceeds to two-split injection (212).

  After the normal injection (208), the multi-split injection (210), and the two-split injection (212), the process proceeds to the complete explosion determination (214). In this complete explosion determination (214), the remaining cylinders are injected. The state is divided into normal injection (208), multi-split injection (210), and 2-split injection (212), and after complete explosion determination (214), the routine proceeds to post-startup injection (216).

  The confirmation of the number of injection cylinders in FIG. 2 will be described. After the split injection start process (302), the process proceeds to the complete explosion determination (304). If this complete explosion determination (304) is NO, the split injection start is started. Returning to the process (302), if the complete explosion determination (304) is YES, the process proceeds to the cylinder counter determination (306).

  This determination of the cylinder counter (306) is to determine whether or not the injection is performed in the N cylinder set. When the determination of the cylinder counter (306) is NO, the above-described split injection start process (302) is performed. ), If the determination (306) of the cylinder counter is YES, the routine proceeds to post-start injection (308).

  The injection amount in one step of FIG. 3 will be described. After the divided injection and division number setting process (402), the divided injection start process (404) is performed, and the fuel pressure reading process (406) is performed.

After performing this fuel pressure reading process (406), the injection amount is obtained by correcting the equation injection amount = base X fuel pressure (408), and the equation injection amount = 1 / n.
A more divided injection amount is obtained (410), and the number of injections is
Number of injections = N
It moves to judgment (412) of whether it is.

This number of injections
Number of injections = N
If the determination (412) is NO in the determination (412) of whether or not, the process returns to the processing (408) for obtaining the injection amount by the formula injection amount = base X fuel pressure correction, and the determination (412) is YES In this case, the program proceeds to the end of the program (414).

The split selection during the set injection in FIG. 4 will be described. During the set injection, the split selection program during the set injection starts (502), and it is determined whether or not the formula engine speed> threshold value is satisfied ( 504). The threshold is an arbitrary engine speed, but the complete explosion determination value can be used as it is.

In the determination (504) of whether or not the above formula engine speed> threshold value is satisfied (504), if the engine speed exceeds the threshold value and the determination (504) is YES, the split injection stop process (506) If the engine speed is equal to or lower than the threshold value, that is, if the determination (504) is NO, the process proceeds to the split injection continuation process (508).

  After the split injection stop process (506) and the split injection continuation process (508), the routine proceeds to cylinder counter determination (510).

This cylinder counter judgment (510) is for judging whether or not the fuel is injected in the N cylinder set. When the cylinder counter judgment (510) is NO, the above-mentioned formula engine speed> threshold value is satisfied. Returning to the determination (504) of whether or not it is established, and when the determination (510) of the cylinder counter is YES, the routine proceeds to post-startup injection (412).

  Thereby, in the injection control means 104 that divides and injects the fuel injection amount at the time of starting into a plurality of times according to the engine water temperature detected by the water temperature sensor 90 which is the engine water temperature detecting means, the division number is the engine water temperature. The lower the value is, the larger the number is set, and the number of times of injection by split injection is controlled to be set to a number that is increased by an integral multiple of the total number of cylinders of the engine 2. It is possible to promote the conversion, improve the startability, and further reduce wrinkles.

  In addition, there are provided cumulative divided injection number counting means 106 for counting the number of injections by split injection from the start of start, and start completion means 108 for determining whether or not the engine 2 has been completely started, and split injection is started. The engine speed detected by the crank angle sensor 82, which is the engine speed detecting means, is counted by the cumulative divided injection number counting means 106 even when the engine 2 is determined to be started by the start completion means 108. Until the number of cumulative divided injections reaches the number of injections by the next set divided injection, the engine operates to inject the starting injection amount. Therefore, the stability at the time of starting can be improved.

  Further, when the fuel injection amount at the time of start-up is divided into two by the injection control means 104, the relationship between the interval time between the first injection amount and the second injection amount is such that the lower the engine water temperature, the longer the interval time. With the configuration in which a control function is added to make the setting short, the startability at a low temperature can be improved even in the two-split injection.

  The present invention is not limited to the above-described embodiments, and various application modifications are possible.

For example, in the embodiment of the present invention, in the case of two-split injection, as is apparent from FIG. 7, the first injection amount A and the second injection amount B are implemented, but as shown in FIG. Thus, the magnitude relationship between the first injection amount A and the second injection amount B is as follows:
A> B
Besides
A <B
In addition, in the injection interval T between the first injection amount A and the second injection amount B,
A> B
In this case, when the injection interval T is α,
A <B
In this case, the injection interval T can be set to β smaller than α.
It should be noted that α and β take smaller values as the engine water temperature decreases.

  In other words, it can contribute to the promotion of atomization of fuel at the start of low temperature and cryogenic temperature, the improvement of startability, and the reduction of soot.

  In the embodiment of the present invention, the engine water temperature is used when setting the number of divisions of the fuel injection amount at start-up and the injection interval between the first injection amount and the second injection amount in the case of the two-split injection. However, in addition to the engine water temperature, a special configuration using an ambient temperature such as an intake air temperature or an outside air temperature is also possible.

  In other words, by using the ambient temperature composed of the intake air temperature, the outside air temperature, etc., the number of divisions of the fuel injection amount at start-up and the injection interval between the first injection amount and the second injection amount in the case of the two-split injection are set. By setting, an accurate setting that matches the current situation becomes possible, which is practically advantageous.

3 is a flowchart for selecting an injection method of an engine start-up injection control apparatus according to an embodiment of the present invention. It is a flowchart for confirmation of the number of injection cylinders of the injection control device at the time of engine start. It is a flowchart for the injection quantity of 1 process of the starting injection control apparatus of an engine. It is a flow chart for division selection during set injection of an engine starting injection control device. It is a system diagram of an engine start-up injection control device. It is a time chart of a crank angle signal. It is a time chart of start time division injection. It is a time chart which shows the injection method at the time of complete explosion determination (when complete explosion determination is not caught in a cylinder on the way). It is a time chart which shows the injection method at the time of complete explosion determination (when complete explosion determination is caught in the middle cylinder). It is a schematic explanatory drawing of the time chart in 2 division | segmentation injection which shows the other 1st Example of this invention.

Explanation of symbols

2 Engine 10 Combustion chamber 12 Air cleaner 14 Intake pipe 16 Throttle body 18 Surge tank 20 Intake manifold 24 Throttle valve 26 Exhaust manifold 30 Catalytic converter 32 Exhaust passage 34 Supercharger (turbocharger)
42 Bypass passage 44 Intercooler 46 Fuel injection valve 48 Fuel supply passage 50 Fuel tank 52 Fuel filter 54 Fuel pump 56 Regulator passage 58 Pressure regulator 60 2-way check valve 62 Evaporation passage 64 Canister 66 1-way check valve 68 Purge passage 70 Idle air passage 72 ISC valve 74 Ignition coil 76 PCV valve 78 First blow-by gas passage 80 Second blow-by gas passage 82 Crank angle sensor 84 Throttle sensor 86 Knock sensor 88 Intake air temperature sensor 90 Water temperature sensor 92 Pressure sensor 94 O2 sensor 96 Control means ("Engine" Also called “control module”.)
98 Main switch 100 Fuse 102 Battery 104 Injection control means 106 Cumulative divided injection frequency counting means 108 Start completion means

Claims (3)

  According to the engine water temperature detecting means capable of detecting the engine water temperature, the engine speed detecting means capable of detecting the engine speed, and the engine water temperature detected by the engine water temperature detecting means, the fuel injection amount at the time of starting is plural times. In the engine start-up injection control device having the injection control means for dividing and injecting the fuel, the number of divisions is set to be larger as the engine water temperature is lower, and the number of injections by the divided injection is an integer of the total number of cylinders An engine start-time injection control device characterized in that a function for controlling to set the number of times to increase by a factor of two is added to the injection control means.   A cumulative divided injection number counting means for counting the number of injections by split injection from the start of the start is provided, and a start completion means for determining whether or not the engine has been completely started is provided. Even when it is determined that the engine has been started by the start completion means, the cumulative number of divided injections counted by the cumulative divided injection number counting means is determined by the next set divided injection. 2. The engine starting injection control device according to claim 1, wherein the starting injection amount is injected until the number of injections is reached.   The engine fuel temperature detecting means capable of detecting the engine water temperature, the engine speed detecting means capable of detecting the engine speed, and the fuel injection amount at the start-up according to the engine water temperature detected by the engine water temperature detecting means. In the engine start-up injection control device provided with the injection control means for performing injection, the relationship between the first injection amount, the second injection amount, and the interval time is controlled so that the interval time is set shorter as the engine water temperature is lower. An engine start-time injection control device, wherein a function is provided in addition to the injection control means.

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