JP4466697B2 - Fuel injection control device for internal combustion engine - Google Patents

Description

  The present invention relates to a fuel injection control device for an internal combustion engine capable of heating fuel before injection.

  In recent years, in the automobile industry, various efforts have been made to cope with changes in the environment surrounding automobiles. For example, in the field of internal combustion engines, efforts have been made for so-called multi-fuel internal combustion engines that can be operated even with fuels having different fuel properties. A vehicle equipped with this kind of multi-fuel internal combustion engine is generally called a flexible fuel vehicle (FFV). For example, any of gasoline fuel, alcohol fuel, or a mixed fuel thereof is used. However, it is known to improve the environmental performance such as the suppression of the consumption of fossil fuels such as gasoline fuel, which can be operated and the limits of reserves continue to be sought. For example, the following Patent Document 1 discloses a multi-fuel internal combustion engine that is operated using an alcohol mixed fuel composed of gasoline fuel and alcohol fuel.

  By the way, in general, alcohol fuel is inferior to gasoline fuel in terms of evaporation characteristics (that is, the latent heat of evaporation is large), so at the time of low temperature start with the outside air temperature, engine cooling water temperature and engine lubricating oil temperature being low The higher the alcohol concentration, the worse the startability. For this reason, conventionally, there is known a technique for improving evaporation characteristics by heating the fuel before injection by a heating means such as a heater, thereby improving low temperature startability. For example, this technique is disclosed in Patent Document 2 below.

JP-A-2-305335 Japanese Patent Laid-Open No. 5-209579

  Here, in the technology for improving the low temperature startability by heating such fuel, as the fuel is injected, the low temperature fuel upstream of the heating means (that is, the fuel tank side) is warmed by the heating means. Before being sent to the fuel injection valve side. Therefore, in such a technique, the fuel that has been warmed in advance by the heating means mixes with the low-temperature fuel on the fuel supply path and lowers the temperature, so that the evaporation characteristics that have been improved are reduced. Startability cannot be improved.

  Accordingly, the present invention provides a fuel injection control device for an internal combustion engine that can improve the disadvantages of the conventional example and can effectively improve the low temperature startability by the heated fuel. For that purpose.

  In order to achieve the above object, according to the first aspect of the present invention, the fuel of the internal combustion engine capable of injecting the heated fuel after delivery from the fuel pump to the fuel injection valve for each cylinder connected to the fuel delivery pipe. The injection control device is provided with fuel pump control means for stopping the driving of the fuel pump until the heated fuel in the fuel delivery pipe becomes a predetermined amount or less.

  The fuel injection control device for an internal combustion engine according to claim 1 can stop the supply of unheated fuel into the fuel delivery pipe and inject only the heated fuel.

In order to achieve the above object, according to the second aspect of the present invention, the internal combustion engine capable of injecting the heated fuel after delivery from the fuel pump to the fuel injection valve for each cylinder connected to the fuel delivery pipe. In the fuel injection control apparatus, the first fuel injection cylinder specifying means for specifying the first fuel injection cylinder to which fuel is first supplied at the time of engine start , and the non-heated fuel supplied into the fuel delivery pipe are used for low temperature start. The fuel pump control means for reducing the fuel delivery amount of the fuel pump according to the identified first fuel injection cylinder and the injection order of each fuel injection valve is provided so as not to lower the performance.

In order to achieve the above object, according to the third aspect of the present invention, an internal combustion engine capable of injecting heated fuel after delivery from the fuel pump to a fuel injection valve for each cylinder connected to a fuel delivery pipe. In the fuel injection control apparatus, the first fuel injection cylinder specifying means for specifying the first fuel injection cylinder to which fuel is first supplied at the time of engine start, and the specified first fuel injection cylinder and each fuel injection valve Non-heated fuel injection valve specifying means for specifying a fuel injection valve for injection of non-heated fuel supplied into the fuel delivery pipe based on the injection order, and injection timing of non-heated fuel by the specified fuel injection valve And a fuel pump control means for reducing the amount of fuel delivered from the fuel pump as soon as the fuel gas comes.

  Thus, the fuel injection control device for the internal combustion engine according to claims 2 and 3 reduces the supply amount of the non-heated fuel into the fuel delivery pipe according to the first fuel injection cylinder, and only the heated fuel is supplied. Can be injected. Further, by stopping the supply of unheated fuel, a negative pressure is generated in the fuel delivery pipe, and unheated fuel is supplied into the fuel delivery pipe in spite of an unintentional increase in the negative pressure. The fuel injection control device supplies the non-heated fuel in an amount corresponding to the first fuel injection cylinder into the fuel delivery pipe, so that an increase in the negative pressure can be suppressed.

  The fuel injection control device for an internal combustion engine according to the present invention can operate the internal combustion engine using only heated fuel by suppressing the inflow of unheated fuel into the fuel delivery pipe. Therefore, this fuel injection control device can maintain the effect of improving the startability at the low temperature start by the heated fuel without being hindered by the non-heated fuel. That is, the effect of improving the low-temperature startability by the heated fuel becomes effective by the fuel injection control device of the internal combustion engine.

  Embodiments of a fuel injection control device for an internal combustion engine according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

  First Embodiment A fuel injection control device for an internal combustion engine according to a first embodiment of the present invention will be described with reference to FIGS. Hereinafter, the fuel injection control apparatus according to the first embodiment will be described in detail while explaining an example of the internal combustion engine to be applied.

  The internal combustion engine exemplified here is a so-called flexible fuel vehicle that can be operated even by using fuels having different fuel properties such as gasoline fuel, alcohol fuel (ethanol, methanol, butanol, etc.) or a mixed fuel thereof. 1 is a multi-fuel internal combustion engine, in which various control operations such as combustion control are executed by an electronic control unit (ECU) 1 shown in FIG. The electronic control unit 1 includes a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) that stores a predetermined control program and the like, and a RAM (Random Access) that temporarily stores the calculation result of the CPU. Memory) and a backup RAM for storing information prepared in advance.

  First, the configuration of the internal combustion engine exemplified here will be described with reference to FIG. In FIG. 1, only one cylinder is shown for convenience, but a plurality of cylinders are actually provided.

  The internal combustion engine includes a cylinder head 11, a cylinder block 12, and a piston 13 that form a combustion chamber CC. Here, the cylinder head 11 and the cylinder block 12 are fastened with bolts or the like via the head gasket 14 shown in FIG. 1, and the recess 11a on the lower surface of the cylinder head 11 and the cylinder bore 12a of the cylinder block 12 formed thereby. The piston 13 is disposed so as to be capable of reciprocating in the space. And the combustion chamber CC mentioned above is comprised by the space enclosed by the wall surface of the recessed part 11a of the cylinder head 11, the wall surface of the cylinder bore 12a, and the top surface 13a of the piston 13. FIG.

  This internal combustion engine sends air and fuel into the combustion chamber CC in accordance with operating conditions such as engine speed and engine load, and executes combustion control in accordance with the operating conditions. The air is sucked from the outside through the intake passage 21 and the intake port 11b of the cylinder head 11 shown in FIG. On the other hand, the fuel is supplied using the fuel supply device 50 shown in FIG.

  First, the air supply path will be described.

  On the intake passage 21 of the internal combustion engine, an air cleaner 22 for removing foreign matters such as dust contained in air introduced from the outside, and an intake air amount detection means 23 for detecting the amount of intake air from the outside are provided. ing. As the intake air amount detection means 23, an air amount detection sensor such as an air flow meter that directly detects the intake air amount, an intake pipe pressure sensor that detects the pressure in the intake passage 21 (ie, intake pressure), and the like are conceivable. When the latter intake pipe pressure sensor is used, the intake air amount is obtained indirectly from the intake pressure and the engine speed. In this internal combustion engine, the detection signal of the intake air amount detection means 23 is sent to the electronic control unit 1, and the electronic control unit 1 calculates the intake air amount, the engine load and the like based on the detection signal. The engine speed can be grasped from the detection signal of the crank angle sensor 16 that detects the rotation angle of the crankshaft 15.

  A throttle valve 24 for adjusting the amount of intake air into the combustion chamber CC and a throttle valve actuator 25 for opening and closing the throttle valve 24 are provided downstream of the intake air amount detection means 23 on the intake passage 21. And are provided. In the electronic control device 1 of the first embodiment, the throttle valve actuator 25 is driven and controlled according to the operating conditions, and the throttle valve 24 is adjusted so as to have a valve opening degree (in other words, intake air amount) according to the operating conditions. Throttle valve control means for adjusting the valve opening angle is prepared. Here, the throttle valve actuator 25 and the throttle valve control means constitute a throttle valve opening control means. For example, the throttle valve 24 is adjusted so that the intake air amount necessary for achieving the air-fuel ratio corresponding to the operating conditions is sucked into the combustion chamber CC. This internal combustion engine is provided with a throttle opening sensor 26 that detects the valve opening of the throttle valve 24 and transmits the detection signal to the electronic control unit 1.

  On the other hand, one end of the intake port 11b opens to the combustion chamber CC, and an intake valve 31 that opens and closes the opening is disposed in the opening portion. The number of openings may be one or more, and an intake valve 31 is provided for each opening. Therefore, in this internal combustion engine, air is sucked into the combustion chamber CC from the intake port 11b by opening the intake valve 31 and closed to the combustion chamber CC by closing the intake valve 31. Air inflow is blocked.

  Here, as the intake valve 31, for example, there is a valve that is driven to open and close in accordance with the rotation of an intake camshaft (not shown) and the elastic force of an elastic member (string spring). In this type of intake valve 31, by interposing a power transmission mechanism such as a chain or a sprocket between the intake side camshaft and the crankshaft 15, the intake side camshaft is interlocked with the rotation of the crankshaft 15, Open / close drive is performed at a preset opening / closing timing. In the internal combustion engine illustrated here, the intake valve 31 that is driven to open and close in synchronization with the rotation of the crankshaft 15 can be applied.

  However, the internal combustion engine may be provided with a variable valve mechanism such as a so-called variable valve timing and lift mechanism that can change the opening / closing timing and lift amount of the intake valve 31, and thereby the opening / closing timing of the intake valve 31. And the lift amount can be changed to a suitable one according to the operation condition and the operation mode. Furthermore, in this internal combustion engine, a so-called electromagnetically driven valve that opens and closes the intake valve 31 using electromagnetic force may be used in order to obtain the same effect as the variable valve mechanism.

  Next, the fuel supply device 50 will be described.

  As this fuel supply device 50, the fuel in one fuel tank is injected into the intake port 11b and / or into the combustion chamber CC, and the fuel having different fuel properties stored in a plurality of fuel tanks is mixed into the fuel mixing device. It can be considered that the mixture is mixed in the intake port 11b and / or injected into the combustion chamber CC. In the first embodiment, a port injection type in which the fuel F stored in one fuel tank 41 is injected into the intake port 11b and led to the combustion chamber CC together with the intake air will be exemplified.

  Specifically, the fuel supply device 50 distributes the fuel F in the fuel passage 51 to each cylinder, and a feed pump 52 as a fuel pump that sucks the fuel F from the fuel tank 41 and sends it to the fuel passage 51. A fuel delivery pipe 53 and a fuel injection valve (fuel injection means) 54 for each cylinder that injects fuel F supplied from the fuel delivery pipe 53 into each intake port 11b.

  The fuel supply device 50 controls the feed pump 52 and the fuel injection valve 54 to be controlled by the electronic control device 1 that also functions as a fuel injection control device in accordance with the operating conditions, whereby the fuel injection amount corresponding to the operating conditions is achieved. The fuel F is injected under fuel injection conditions such as fuel injection timing and fuel injection period. For example, the electronic control unit 1 causes the fuel F to be sucked up from the fuel tank 41 by the feed pump 52, and causes the fuel injection valve 54 to perform injection under fuel injection conditions corresponding to the operating conditions.

  The fuel F supplied to the intake port 11b in this way is supplied into the combustion chamber CC together with the opening of the intake valve 31 while mixing with the air described above in the intake port 11b, and is ignited according to operating conditions. When it is time, combustion is performed by the ignition operation of the spark plug 61. The in-cylinder gas (combustion gas) after being burned is discharged from the combustion chamber CC to the exhaust port 11c shown in FIG. 1 and discharged to the atmosphere through the exhaust passage 81.

  An exhaust valve 71 that opens and closes an opening between the exhaust port 11c and the combustion chamber CC is disposed. The number of openings may be one or more, and the exhaust valve 71 described above is provided for each opening. Accordingly, in this internal combustion engine, combustion gas is discharged from the combustion chamber CC to the exhaust port 11c by opening the exhaust valve 71, and closing the exhaust valve 71 to the combustion gas exhaust port 11c. Is blocked.

  Here, as the exhaust valve 71, as in the intake valve 31 described above, a valve with a power transmission mechanism, a valve with a variable valve mechanism such as a so-called variable valve timing & lift mechanism, or a so-called electromagnetically driven valve is used. Can be applied.

  An exhaust purification device 82 is disposed on the exhaust passage 81 to purify harmful components in the exhaust gas.

  Here, as the fuel F that can be used in the engine, as described above, gasoline fuel, alcohol fuel, or alcohol mixed fuel can be considered. The alcohol mixed fuel is a mixed fuel of an alcohol fuel and at least one fuel having a different fuel property, and here, it is assumed that it is mixed with a hydrocarbon fuel (for example, gasoline fuel). Therefore, if pure gasoline fuel is used, problems are unlikely to occur, but if pure alcohol fuel or alcohol blended fuel is used during cold start, the alcohol fuel or alcohol blended fuel is less than gasoline fuel. Since it is inferior in terms of evaporation characteristics, it may not be possible to ignite with the spark plug 61, or even if ignited, there is a possibility of misfiring immediately. Such inconvenience becomes more noticeable as the alcohol concentration increases.

  Therefore, in this internal combustion engine, in order to cope with deterioration of startability at the time of low temperature start when operating with alcohol fuel or alcohol mixed fuel, heating means such as a heater is provided on the fuel supply device 50, and the fuel F is preliminarily provided. Evaporation characteristics are improved by warming.

  For example, here, as shown in FIG. 2, a heating means 55 is provided in the fuel delivery pipe 53, and the fuel F in the fuel delivery pipe 53 sent from the fuel passage 51 is heated. The ON / OFF operation of the heating means 55 is controlled by the electronic control device 1. In other words, for example, when the warm-up operation is completed or when the vehicle is operated with gasoline fuel, it is considered that the ignition operation is appropriately performed without heating the fuel F. Therefore, the heating means 55 is mainly used for alcohol fuel having poor low temperature startability. Alternatively, a heating operation (ON operation) is performed when the engine is started with alcohol mixed fuel. For example, if the engine cooling water temperature is lower than a predetermined value when an ignition ON signal is detected or a door lock release signal is detected, the heating operation is performed when an engine start operation (that is, a cranking operation) is performed. Is also executed in advance. Further, the heating operation may be executed when the engine coolant temperature becomes lower than a predetermined temperature even after the warm-up operation is completed. The engine cooling water temperature can be detected from the water temperature sensor 17 shown in FIG.

  By the way, the feed pump 52 is generally always driven unless fuel cut or the like is performed. For this reason, when the fuel F is injected from the fuel injection valve 54, the fuel F is replenished from the fuel passage 51 by the amount injected into the fuel delivery pipe 53. For example, FIG. 2 shows a fuel delivery pipe 53 for an in-line four-cylinder internal combustion engine and first to fourth fuel injection valves 54a to 54d for # 1 cylinder to # 4 cylinder. Thus, when the fuel F is injected from the first fuel injection valve 54 a, the fuel F used for the injection is pushed into the fuel delivery pipe 53 by the pressure feeding operation of the feed pump 52. Here, the fuel supply port in the fuel delivery pipe 53 (the joint portion between the fuel delivery pipe 53 and the fuel passage 51) is set on the fourth fuel injection valve 54d side.

  Here, FIG. 2 shows a state before starting the engine and before starting the injection of the fuel F. Therefore, when starting at a low temperature with alcohol fuel or alcohol mixed fuel, in the state shown in FIG. The fuel F in the pipe 53 is in a state heated by the heating means 55. Therefore, as shown in FIG. 3, when heated fuel (hereinafter referred to as “heated fuel”) F is injected from the first fuel injection valve 54a, the amount of unheated fuel used for the injection ( Hereinafter, this is referred to as “non-heated fuel.”) F is sent from the fuel passage 51 into the fuel delivery pipe 53. Since each fuel injection valve (the first to fourth fuel injection valves 54 a to 54 d) performs fuel injection continuously in a very short time, it is newly fed into the fuel delivery pipe 53. Most of the heated fuel F is injected soon after being heated by the heating means 55. Further, since the non-heated fuel F takes the heat of the heated fuel F in the fuel delivery pipe 53, the evaporation characteristic of the heated fuel F improved by the heating operation of the heating means 55 is lowered again. Therefore, in this internal combustion engine, if the non-heated fuel F or the heated fuel F from which heat has been removed is injected at an early stage after the engine starting operation, misfires and the like are caused. It may not be possible to plan.

  Therefore, in the first embodiment, the feed pump 52 is stopped only for a predetermined time when the heating operation of the fuel F by the heating means 55 is being performed, and the supply of the non-heated fuel F into the fuel delivery pipe 53 is performed. Is not done.

  For example, in this internal combustion engine, fuel injection is performed in the order of # 1 cylinder → # 3 cylinder → # 4 cylinder → # 2 cylinder, and if the fuel F can be ignited at least three times continuously at a low temperature start, a stable combustion operation is performed thereafter. Shall be done. Further, in the fuel supply device 50 of the internal combustion engine, the fuel that can be retained in the fuel delivery pipe 53 so that the fuel can be injected at least three times even if the fuel F is not supplied into the fuel delivery pipe 53. The amount and the fuel injection amount of each of the first to fourth fuel injection valves 54a to 54d are set. In this case, by stopping the feed pump 52, for example, even after the heated fuel F is injected from the first fuel injection valve 54a of the # 1 cylinder, as shown in FIG. Is not sent, so the heated fuel F is also injected from the third fuel injection valve 54c of the # 3 cylinder that performs fuel injection next, and the fourth fuel injection valve 54d of the # 4 cylinder that performs fuel injection next. As a result, deterioration of the cold startability is avoided.

  Specifically, the electronic control device 1 (fuel injection control device) of the first embodiment determines whether or not the heating operation to the fuel F by the heating means 55 is being performed as shown in the flowchart of FIG. Is performed (step ST1). This determination can be made by observing whether the electronic control unit 1 itself commands the heating means 55 to perform an ON operation or an OFF operation.

  Here, if the heating operation is not performed, the fuel pump control means of the electronic control unit 1 proceeds to step ST4 described later to start driving the feed pump 52. Here, assuming that the feed pump 52 has already been driven, the driving is continued.

  On the other hand, when the heating operation by the heating unit 55 is being executed, the fuel pump control unit gives a command to stop the drive operation of the feed pump 52 (step ST2).

  As a result, in the fuel supply device 50 of the internal combustion engine, the pressure feed of the non-heated fuel F from the feed pump 52 is stopped, so that only the heated fuel F remains in the fuel delivery pipe 53. Therefore, in this fuel supply device 50, even if the fuel injection from the fuel injection valve arranged near the fuel supply port of the fuel delivery pipe 53 is performed at an early stage after the engine start operation, the fuel injection valve Will inject only the heated fuel F with improved evaporation characteristics. For this reason, in such an internal combustion engine, low temperature startability is improved.

  For example, when the cylinder # 1 is the first fuel injection target cylinder (hereinafter referred to as “first fuel injection cylinder”) at the time of low temperature start, the second fuel injection is performed (hereinafter referred to as “second fuel injection cylinder”). The heated fuel F is also supplied to the # 3 cylinder, which is referred to as “fuel injection cylinder”), and the # 4 cylinder, which is the third fuel injection cylinder (hereinafter referred to as “third fuel injection cylinder”). That is, in this case, the third fuel injection valve 54c of the # 3 cylinder that performs the second injection operation near the fuel supply port of the fuel delivery pipe 53 and the fourth fuel injection of the # 4 cylinder that performs the third injection operation. Since the heated fuel F is also injected from the valve 54d, poor ignition and misfire can be avoided and good low temperature startability can be obtained. Here, if it is assumed that the feed pump 52 has not been stopped in this case, the # 3 cylinder, which is the second fuel injection cylinder, is supplied with the heated fuel F having a reduced evaporation characteristic due to heat radiation to the non-heated fuel F. There is a high possibility that the non-heated fuel F is supplied to the # 4 cylinder, which is the next third fuel injection cylinder, as it is. Therefore, the internal combustion engine is in a low temperature state due to poor ignition or misfire. There is a risk that starting may become impossible.

  Further, when the # 2 cylinder is the first fuel injection cylinder at the time of cold start, the injection operation is performed in the order of # 2 cylinder → # 1 cylinder → # 3 cylinder, but it is assumed that the feed pump 52 has not been stopped. For example, the non-heated fuel F is likely to be supplied as it is to the # 3 cylinder, which is the third fuel injection cylinder, so that the internal combustion engine cannot be started at a low temperature due to poor ignition or misfire. There is a risk of it. However, in this case, since the feed pump 52 is stopped and the supply of the non-heated fuel F into the fuel delivery pipe 53 is stopped, the third fuel injection of the # 3 cylinder near the fuel supply port of the fuel delivery pipe 53 is performed. The heated fuel F is also injected from the valve 54c, so that poor ignition and misfiring can be avoided and good low temperature startability can be obtained.

  In addition, when the # 3 cylinder is the first fuel injection cylinder at the time of low temperature start, the injection operation is performed in the order of # 3 cylinder → # 4 cylinder → # 2 cylinder, but it is assumed that the feed pump 52 has not been stopped. For example, the # 4 cylinder, which is the second fuel injection cylinder, is very likely to be supplied with the non-heated fuel F as it is, so that the internal combustion engine cannot be started at a low temperature due to poor ignition or misfiring. easy. That is, the fourth fuel injection valve 54d of the # 4 cylinder is disposed closest to the fuel supply port of the fuel delivery pipe 53, so that even when a little unheated fuel F enters the fuel delivery pipe 53, The non-heated fuel F is injected and the low temperature startability is deteriorated. However, in this case, since the feed pump 52 is stopped and the supply of the non-heated fuel F into the fuel delivery pipe 53 is stopped, the fourth fuel of the # 4 cylinder closest to the fuel supply port of the fuel delivery pipe 53 is used. The heated fuel F is also injected from the injection valve 54d, and ignition failure, misfire, etc. are avoided, and good low temperature startability can be obtained.

  When the # 4 cylinder is the first fuel injection cylinder at the time of low temperature start, the injection operation is performed in the order of # 4 cylinder → # 2 cylinder → # 1 cylinder, so even if the feed pump 52 is driven The heated fuel F is supplied to each cylinder, and there is little possibility that the low-temperature startability is deteriorated. For this reason, in such a case, the feed pump 52 may not be stopped on condition that the first fuel injection cylinder can be specified as the # 4 cylinder. The identification may be performed based on, for example, the rotation angle of the crankshaft 15 or the like.

  Further, if this internal combustion engine cannot secure a stable combustion state at the time of low temperature start even by supplying the heated fuel F three times continuously, the capacity capable of retaining the fuel F in the fuel delivery pipe 53 is increased. Just make it bigger.

  In this way, the electronic control device 1 (fuel injection control device) of the first embodiment stops the drive of the feed pump 52 in order to improve the low temperature startability, but the stop state continues for a long time, so that the inside of the fuel delivery pipe 53 The fuel F is insufficient, and fuel injection from the fuel injection valve 54 is not performed, so that the combustion operation is stopped in the internal combustion engine.

  Accordingly, the fuel pump control means of the electronic control unit 1 according to the first embodiment determines whether or not the number of fuel injections starting from the time of fuel injection to the first fuel injection cylinder has become a predetermined number α or more. (Step ST3), and the feed pump 52 is kept stopped until an affirmative determination (determination that the number of fuel injections has reached the predetermined number α) is made.

  On the other hand, if an affirmative determination is made in step ST3, it is determined that further stoppage of the feed pump 52 causes fuel shortage in the fuel delivery pipe 53, and the fuel pump control means drives the feed pump 52. Is started (step ST4). Thereby, in this internal combustion engine, it becomes possible to avoid the combustion failure caused by the fact that the fuel F is not injected.

  In this example, regarding the relationship between the capacity in the fuel delivery pipe 53 and the fuel injection amount of the fuel injection valve 54 (first to fourth fuel injection valves 54a to 54d), the inside of the fuel delivery pipe 53 is fuel F. If it is satisfied, fuel injection can be performed three times without replenishment. Furthermore, this internal combustion engine is assumed to perform a stable combustion operation after that if the fuel F can be ignited at least three times continuously at a low temperature start. For this reason, the predetermined number of times α here is “α = 3”.

  As described above, the fuel injection control apparatus according to the first embodiment can prevent the non-heating fuel F from being injected or the temperature of the heating fuel F from being lowered due to the non-heating fuel F at the time of low temperature start, and only the heating fuel F is injected. Therefore, the startability at that time can be improved.

  Incidentally, in step ST3 described above, the drive start timing of the feed pump 52 is determined by comparing the number of fuel injections with the predetermined number α. Instead, this determination is based on the heated fuel in the fuel delivery pipe 53. You may carry out by observing whether the residual amount of F was reduced to below predetermined amount. In this case, it is determined that it is time to start driving the feed pump 52 when the remaining amount of the heated fuel F becomes a predetermined amount or less. The remaining amount of the heated fuel F in the fuel delivery pipe 53 can be grasped from the total fuel injection amount and the number of fuel injections starting from the first fuel injection cylinder. Therefore, as the predetermined amount in this case, the remaining amount of the heated fuel F in the fuel delivery pipe 53 when the fuel injection is performed the predetermined number of times α may be set.

  The determination may be made using an elapsed time calculated from the time of fuel injection related to the first fuel injection cylinder. In this case, when the elapsed time becomes equal to or longer than a predetermined time, it is determined that the feed pump 52 is to be started. Here, as the predetermined time in this case, an elapsed time from the time of fuel injection related to the first fuel injection cylinder when the fuel injection is performed a predetermined number of times α may be set.

  Further, in the first embodiment, the heating means 55 is provided in the fuel delivery pipe 53, but the heating means 55 may be disposed on the fuel passage 51 downstream of the feed pump 52. In this case, the heated fuel F exists downstream of the heating means 55 in the fuel passage 51.

  Furthermore, in the above description, an in-line four-cylinder internal combustion engine has been described as an example. However, the fuel injection control device of the first embodiment described above can also be applied to a different type of internal combustion engine. For example, a V-type 6-cylinder internal combustion engine will be described here. In this internal combustion engine, fuel injection is performed in the order of # 1 cylinder → # 2 cylinder → # 3 cylinder → # 4 cylinder → # 5 cylinder → # 6 cylinder, and if the fuel F can be ignited at least three times continuously at low temperature start, then Also, a stable combustion operation is performed.

  The V-type 6-cylinder internal combustion engine is provided with a fuel delivery pipe 153 shown in FIG. 6 and first to sixth fuel injection valves 154a to 154f for cylinders # 1 to # 6. The fuel delivery pipe 153 includes a first delivery pipe main body 153a for one bank having # 1, # 3, and # 5 cylinders, and the other bank having # 2, # 4, and # 6 cylinders. The second delivery pipe main body 153b and the fuel passage 153c for communicating the first and second delivery pipe main bodies 153a and 153b with each other. Each of the first and second delivery pipe main bodies 153a and 153b is provided with heating means 155 such as a heater, and each of the heating means 155 includes the first and second delivery pipe main bodies 153a and 153b. The fuel F supplied to the inside is heated.

  Here, the first delivery pipe main body 153a is connected to the first, third and fifth fuel injection valves 154a, 154c and 154e, and the second delivery pipe main body 153b is connected to the second, fourth and fourth fuel injection valves 154a. Six fuel injection valves 154b, 154d, and 154f are connected. In this fuel delivery pipe 153, the fuel passage 51 is connected to the second delivery pipe main body 153b, and the fuel F pumped from the feed pump 52 is supplied to the second delivery pipe main body 153b, and the fuel passage 51 to the first delivery pipe main body 153a. Here, a fuel supply port (a joint portion between the fuel delivery pipe 153 and the fuel passage 51) in the fuel delivery pipe 153 is set on the sixth fuel injection valve 154f side of the second delivery pipe main body 153b.

  Also in this V-type 6-cylinder internal combustion engine, if the electronic control device 1 (fuel injection control device) is heating the fuel F by the respective heating means 155, the fuel pump control means performs the steps described above. Proceeding to ST2, the drive operation of the feed pump 52 is stopped.

  Thus, in such an internal combustion engine, only the heated fuel F remains in the first and second delivery pipe main bodies 153a, 153b, and the fuel delivery pipe 153 is the same as in the case of the in-line four-cylinder internal combustion engine described above. Even if the fuel injection from the fuel injection valve arranged near the fuel supply port is performed at an early stage after the engine start operation, only the heated fuel F with improved evaporation characteristics is injected from the fuel injection valve. As a result, low temperature startability is improved.

  Here, when the # 1 cylinder is the first fuel injection cylinder at the time of low temperature start, since the injection operation is performed in the order of # 1 cylinder → # 2 cylinder → # 3 cylinder, etc., the feed pump 52 is driven. However, there is a high possibility that the heated fuel F is supplied to each cylinder. For this reason, in such a case, the feed pump 52 does not have to be stopped on condition that the first fuel injection cylinder can be specified as the # 1 cylinder. The same applies to the case where the # 6 cylinder is the first fuel injection cylinder at the low temperature start.

  When the # 3 cylinder is the first fuel injection cylinder at the time of low temperature start, the injection operation is performed in the order of # 3 cylinder → # 4 cylinder → # 5 cylinder, and so on, closer to the fuel supply port of the fuel delivery pipe 153. Since there is a high possibility that the heated fuel F is also injected from the fourth fuel injection valve 154d of the # 4 cylinder as the arranged second fuel injection cylinder, it is specified that the first fuel injection cylinder is the # 3 cylinder. It is not necessary to stop the feed pump 52 on condition that it is obtained.

  On the other hand, when the # 2 cylinder is the first fuel injection cylinder at the time of low temperature start, the injection operation is performed in the order of # 2 cylinder → # 3 cylinder → # 4 cylinder, etc., but it is assumed that the feed pump 52 has not been stopped. Then, since there is a high possibility that the non-heated fuel F is supplied as it is to the # 4 cylinder near the fuel supply port of the fuel delivery pipe 153 as the third fuel injection cylinder, the internal combustion engine has a low temperature due to poor ignition or misfire. There is a possibility that starting in a state becomes impossible. However, in this case, since the feed pump 52 is stopped and the supply of the non-heated fuel F into the fuel delivery pipe 153 is stopped, the fourth fuel injection of the # 4 cylinder near the fuel supply port of the fuel delivery pipe 153 is performed. The heated fuel F is also injected from the valve 154d, so that poor ignition and misfiring can be avoided and good low temperature startability can be obtained. The same applies to the case where the # 4 cylinder is the first fuel injection cylinder at the time of low temperature start. In this internal combustion engine, the third closest to the fuel supply port of the fuel delivery pipe 153 by the stop of the feed pump 52. The heated fuel F is also injected from the sixth fuel injection valve 154f of the # 6 cylinder as the fuel injection cylinder.

  Further, when the # 5 cylinder is the first fuel injection cylinder at the time of low temperature start, since the injection operation is performed in the order of # 5 cylinder → # 6 cylinder → # 1 cylinder, etc., it is assumed that the feed pump 52 has not been stopped. Then, as shown in FIGS. 7 and 8, when fuel is injected from the fifth fuel injection valve 154e of the # 5 cylinder, the # 6 cylinder as the second fuel injection cylinder closest to the fuel supply port of the fuel delivery pipe 153 is obtained. There is a high possibility that the non-heated fuel F is supplied as it is. For this reason, the internal combustion engine in this case may be poorly ignited or misfired, making it impossible to start in a low temperature state. However, also in this case, the feed pump 52 is stopped and the supply of the non-heated fuel F into the fuel delivery pipe 153 is stopped, so that the heated fuel F is also injected from the sixth fuel injection valve 154f of the # 6 cylinder. Thus, in this internal combustion engine, poor ignition and misfire can be avoided and good low temperature startability can be obtained.

  Next, a second embodiment of the fuel injection control device for an internal combustion engine according to the present invention will be described with reference to FIGS. The fuel injection control device of the second embodiment is prepared as one function of the electronic control device 1 as in the first embodiment. In the second embodiment, the fuel injection control apparatus will be described using the in-line four-cylinder internal combustion engine exemplified in the first embodiment.

  In the fuel injection control device of the first embodiment described above, if the fuel F is heated, the feed pump 52 is completely stopped for a predetermined time at the time of low temperature start, and the fuel delivery pipe 53 of the non-heated fuel F is in the fuel delivery pipe 53. The low temperature startability is improved by injecting only the heated fuel F.

  However, when fuel injection is performed with the feed pump 52 stopped, a negative pressure is generated in the fuel delivery pipe 53, and the negative pressure increases as the number of fuel injections in the stopped state increases. Therefore, there is a possibility of causing the following inconvenience.

  First, the non-heated fuel F in the fuel passage 51 may flow into the fuel delivery pipe 53 due to the negative pressure. In that case, the unintended non-heated fuel F deteriorates the low-temperature startability of the internal combustion engine. There is a possibility. That is, depending on the inflow timing of the unheated fuel F, the unheated fuel F or the heated fuel F radiated by the unheated fuel F is injected at an early stage such as the second time or the third time after the start of the fuel injection operation. May end up. In this case, there is a high possibility that the low temperature startability is deteriorated by the injected fuel F. Further, when the fuel injection valve 54 has low airtightness, the negative pressure may cause the combustion gas or air in the combustion chamber CC to be sucked into the fuel delivery pipe 53 via the fuel injection valve 54. Therefore, when the fuel injection valve 54 performs the fuel injection operation next time, only the sucked combustion gas or the like is injected and the fuel F is not injected or the amount of fuel injection is reduced. May cause injection restriction.

  As described above, it is sometimes undesirable to stop the feed pump 52 at any time during fuel heating. In order to improve such inconvenience, even if the non-heated fuel F flows in, low temperature startability When the feed pump 52 is driven, the non-heated fuel F in the fuel passage 51 is forcibly supplied into the fuel delivery pipe 53, while the inflow of the non-heated fuel F may cause deterioration in low-temperature startability. In this case, the forced supply of non-heated fuel F may be suppressed. That is, as a measure for improving the inconvenience, an unheated fuel F having an appropriate flow rate may be supplied from the fuel passage 51 at an appropriate time.

  Specifically, regarding the supply timing and supply amount of the non-heated fuel F into the fuel delivery pipe 53 and the influence of the non-heated fuel F on the low temperature startability, This is related to whether the fuel is injected in stages, and can be determined by specifying the first fuel injection cylinder. That is, in the second embodiment, the drive amount of the feed pump 52 (in other words, the fuel delivery amount from the feed pump 52) is controlled according to the specified first fuel injection cylinder. Therefore, the electronic control unit 1 according to the second embodiment is provided with first fuel injection cylinder specifying means for specifying the first fuel injection cylinder. The fuel pump control means of the electronic control unit 1 is configured to control the amount of fuel delivered from the feed pump 52 at the time of low temperature start according to the first fuel injection cylinder.

  The first fuel injection cylinder specifying means is, for example, the first fuel injection based on the rotation angle of the crankshaft 15 detected by the crank angle sensor 16 and the rotation angle of a camshaft (not shown) related to the intake valve 31 or the exhaust valve 71. The cylinder is specified. That is, by knowing the rotation angle of the crankshaft 15, it is possible to grasp the position of the reciprocating direction of the piston 13 in each cylinder, and further, by knowing the rotation angle of the camshaft, what kind of stroke each cylinder has. Therefore, the first fuel injection cylinder specifying means can specify the first fuel injection cylinder based on these pieces of information.

  If the first fuel injection cylinder is specified in this way, the second fuel injection cylinder and the third fuel are based on the injection order of the respective fuel injection valves 54 (first to fourth fuel injection valves 54a to 54d). It is also possible to specify the injection cylinder and the like. Therefore, when the non-heated fuel F is supplied into the fuel delivery pipe 53, it can be grasped from which fuel injection valve the non-heated fuel F is injected. Hereinafter, the fuel injection valve that injects the non-heated fuel F at that time is referred to as “non-heated fuel injection valve”. The low temperature startability of the internal combustion engine becomes worse as the injection timing of the non-heated fuel F by the non-heated fuel injection valve comes earlier from the injection timing of the heated fuel F related to the first fuel injection cylinder. To go. For this reason, in the second embodiment, the fuel delivery amount of the feed pump 52 is reduced as the injection timing of the non-heated fuel F by the non-heated fuel injection valve comes earlier. For example, in the electronic control unit 1 according to the second embodiment, non-heating is performed based on the information on the first fuel injection cylinder and the injection order of the respective fuel injection valves 54 (first to fourth fuel injection valves 54a to 54d). Non-heated fuel injection valve specifying means for specifying the fuel injection valve is provided. As for the drive amount control of the feed pump 52 corresponding to the first fuel injection cylinder performed by the fuel pump control means, the drive amount of the feed pump 52 increases as the injection timing of the non-heated fuel F by the non-heated fuel injection valve comes earlier. To lower.

  Hereinafter, the control operation at the time of low temperature start of the fuel injection control device (electronic control device 1) of the second embodiment will be described based on the flowchart of FIG. In the internal combustion engine exemplified here, as in the first embodiment, fuel injection is performed in the order of # 1 cylinder → # 3 cylinder → # 4 cylinder → # 2 cylinder.

  First, the electronic control unit 1 according to the second embodiment determines whether or not the heating operation to the fuel F by the heating unit 55 is being performed in the same manner as in the first embodiment (step ST11). .

  Here, if the heating operation is not performed, the electronic control unit 1 ends the control operation. At that time, drive control of the feed pump 52 different from drive amount control of the feed pump 52 described later is executed.

  On the other hand, when the heating operation by the heating means 55 is being executed, the electronic control unit 1 of the second embodiment causes the first fuel injection cylinder specifying means to specify the first fuel injection cylinder (step ST12).

  Then, the fuel pump control means of the second embodiment obtains the drive amount of the feed pump 52 corresponding to the first fuel injection cylinder (step ST13), and according to the drive amount, drive control of the feed pump 52, that is, feed The drive amount of the pump 52 is controlled (step ST14).

  Here, the correspondence between the first fuel injection cylinder and the drive amount of the feed pump 52 is prepared in advance as map data.

  For example, when the # 1 cylinder is the first fuel injection cylinder at the time of cold start, as shown in FIG. 10, the third fuel injection valve 54c or the fourth fuel disposed near the fuel supply port of the fuel delivery pipe 53 is used. The injection valves 54d serve as a second fuel injection cylinder and a third fuel injection cylinder, respectively. For this reason, in this case, if the drive amount of the feed pump 52 is not reduced, the # 3 cylinder, which is the second fuel injection cylinder, is supplied with the heated fuel F whose evaporation characteristics are reduced due to heat radiation to the non-heated fuel F. Since the non-heated fuel F is likely to be supplied as it is to the # 4 cylinder, which is the next third fuel injection cylinder, the internal combustion engine is in a low temperature state due to poor ignition or misfire, etc. There is a possibility that starting at the time becomes impossible.

  Therefore, in this case, the drive amount of the feed pump 52 is reduced so that the non-heated fuel F is not injected from the third fuel injection valve 54c or the fourth fuel injection valve 54d. That is, when the # 1 cylinder is the first fuel injection cylinder at the time of low temperature start, the drive amount of the feed pump 52 is set low, and the map data is determined so that the fuel delivery amount from the feed pump 52 is reduced. Keep it. Thereby, in step ST14 in this case, since the drive amount of the feed pump 52 is reduced, the supply amount of the non-heated fuel F into the fuel delivery pipe 53 is reduced.

  Therefore, in this case, the heated fuel F is also injected from the # 3 cylinder third fuel injection valve 54c that performs the second injection operation and the # 4 cylinder fourth fuel injection valve 54d that performs the third injection operation. As a result, it is possible to avoid poor ignition, misfire, and the like and to obtain good low temperature startability. On the other hand, since the non-heated fuel F is fed into the fuel delivery pipe 53 in a small amount at that time, the increase in the negative pressure is suppressed in the fuel delivery pipe 53, and the intention accompanying the increase in the negative pressure. It is possible to prevent the inflow of the non-heated fuel F and the inflow of the combustion gas or the like through the fuel injection valves 54 (first to fourth fuel injection valves 54a to 54d). For this reason, the unintended injection of the unheated fuel F at an inappropriate time and the injection restriction of the fuel F by the combustion gas can be avoided, so that the low temperature start obtained by the drive amount control of the feed pump 52 can be avoided. The effect of improving sex can be maintained.

  Further, when the # 2 cylinder is the first fuel injection cylinder at the time of low temperature start, the third fuel injection valve 54c arranged near the fuel supply port of the fuel delivery pipe 53 is the third fuel as shown in FIG. It becomes an injection cylinder. For this reason, in this case, if the drive amount of the feed pump 52 is not reduced, there is a high possibility that the non-heated fuel F is supplied to the # 3 cylinder, which is the third fuel injection cylinder, as it is. There is a possibility that starting in a low temperature state becomes impossible due to a failure or misfire.

  Therefore, in this case, the drive amount of the feed pump 52 is reduced so that the non-heated fuel F is not injected from the third fuel injection valve 54c. That is, even if the # 2 cylinder is the first fuel injection cylinder at the time of low temperature start, the map data is set so that the drive amount of the feed pump 52 is set low and the fuel delivery amount from the feed pump 52 is reduced. Is established. Here, the drive amount of the feed pump 52 is reduced so that the # 1 cylinder has the same fuel delivery amount as that of the first fuel injection cylinder at the time of low temperature start, or a slightly larger fuel delivery amount than that. Thereby, in step ST14 in this case, since the drive amount of the feed pump 52 is reduced, the supply amount of the non-heated fuel F into the fuel delivery pipe 53 is reduced.

  Accordingly, in this case, since the heated fuel F is also injected from the third fuel injection valve 54c of the # 3 cylinder that performs the third injection operation, it is possible to avoid poor ignition and misfire, etc. Startability can be obtained. On the other hand, since the non-heated fuel F is fed into the fuel delivery pipe 53 in a small amount at that time, the feed pump 52 is driven in the same manner as when the # 1 cylinder is the first fuel injection cylinder at the low temperature start. The effect of improving the low temperature startability obtained by the quantity control can be maintained.

  When the # 3 cylinder is the first fuel injection cylinder at the time of low temperature start, as shown in FIG. 12, the fourth fuel injection valve 54d disposed near the fuel supply port of the fuel delivery pipe 53 serves as the second fuel. It becomes an injection cylinder. For this reason, in this case, unless the drive amount of the feed pump 52 is decreased, the possibility that the non-heated fuel F is supplied as it is to the # 4 cylinder as the second fuel injection cylinder is extremely high. That is, the fourth fuel injection valve 54d of the # 4 cylinder is disposed closest to the fuel supply port of the fuel delivery pipe 53, so that even when a little unheated fuel F enters the fuel delivery pipe 53, The unheated fuel F is injected. Therefore, in the internal combustion engine at that time, poor ignition or misfire may occur, making it impossible to start in a low temperature state.

  Therefore, in this case, the drive amount of the feed pump 52 is reduced as much as possible so that the non-heated fuel F is not injected from the fourth fuel injection valve 54d. That is, when the # 3 cylinder is the first fuel injection cylinder at the time of low temperature start, the drive amount of the feed pump 52 is set as low as possible, and the map data is set so that the fuel delivery amount from the feed pump 52 is almost eliminated. It is decided. Here, the feed pump 52 is stopped so that the non-heated fuel F is not sent to the feed pump 52. Thereby, in step ST14 in this case, since the drive of the feed pump 52 is stopped, the supply of the non-heated fuel F into the fuel delivery pipe 53 is stopped.

  Accordingly, in this case, since the heated fuel F is also injected from the fourth fuel injection valve 54d of the # 4 cylinder that performs the second injection operation, it is possible to avoid poor ignition and misfire, etc. Startability can be obtained. Here, since the non-heated fuel F is not supplied into the fuel delivery pipe 53 at that time, a negative pressure is generated, but here, the supply of the non-heated fuel F to the # 4 cylinder which is the second fuel injection cylinder. Emphasis will be placed on avoiding misfires, etc. caused by the accident. In this case, the fuel pump control means drives the feed pump 52 when the fuel injection of the fourth fuel injection valve 54d is finished, and supplies the non-heated fuel F into the fuel delivery pipe 53. It is desirable. Thereby, since further increase of the negative pressure is prevented here, the improved low temperature startability is maintained.

  On the other hand, when the # 4 cylinder is the first fuel injection cylinder at the time of low temperature start, the injection operation is performed in the order of # 4 cylinder → # 2 cylinder → # 1 cylinder as shown in FIG. Since the heated fuel F is supplied to each cylinder without adjusting the drive amount, there is little possibility of deteriorating the cold startability. For this reason, in such a case, the drive amount of the feed pump 52 is set so as not to decrease, and the fuel delivery amount from the feed pump 52 does not change (in other words, the maximum or near fuel delivery amount). Map data is determined in advance. That is, in step ST14 in this case, the supply of the non-heated fuel F into the fuel delivery pipe 53 is performed as usual, so the injection amount of the heated fuel F injected from the fourth fuel injection valve 54d of the # 4 cylinder is determined. The unheated fuel F is replenished by the amount. Accordingly, in this case, since the negative pressure in the fuel delivery pipe 53 does not increase, unintended inflow of the non-heated fuel F accompanying the increase in the negative pressure and the fuel injection valve 54 (first to fourth fuels). The inflow of combustion gas or the like through the injection valves 54a to 54d) can be prevented, and the improvement effect of the low temperature startability obtained by the drive amount control of the feed pump 52 can be maintained.

  As described above, the fuel injection control apparatus according to the second embodiment can inject only the heated fuel F while preventing the non-heated fuel F from being injected or the temperature of the heated fuel F from being lowered by the non-heated fuel F at the time of low temperature start. In addition, since the negative pressure in the fuel delivery pipe 53 is prevented by adjusting the supply amount of the non-heated fuel F according to the first fuel injection cylinder at that time, the startability at the low temperature start can be reduced. The improvement effect can be enhanced as compared with the first embodiment.

  In the second embodiment, the heating means 55 is provided in the fuel delivery pipe 53 as in the first embodiment. However, the heating means 55 is disposed on the fuel passage 51 downstream of the feed pump 52. Also good. In this case, since the heated fuel F exists in the fuel passage 51 on the downstream side of the heating means 55, the heated fuel F existing in the fuel passage 51 when the feed pump 52 is driven. Will flow into the fuel delivery pipe 53. Therefore, in this case, the amount of fuel delivered from the feed pump 52 according to the existing amount (in other words, the path length downstream of the heating means 55 in the fuel passage 51) is based on the above-described example. The increase in the negative pressure in the fuel delivery pipe 53 can be further suppressed.

  Here, in the first and second embodiments, the alcohol concentration of the fuel F is illustrated as being constant, but the fuel injection of the first and second embodiments is taken into consideration when the fuel F having a different alcohol concentration is supplied. The control device (electronic control device 1) is preferably provided with alcohol concentration detection means for detecting the alcohol concentration and alcohol concentration estimation means for estimating the alcohol concentration. The alcohol concentration detection means and the alcohol concentration estimation means are made by techniques well known in this technical field, and use detection values of the alcohol concentration sensor, combustion property information at the time of refueling, oxygen concentration in the exhaust gas, etc. To do. In this case, the necessity of the heating operation of the fuel F by the heating means 55 (heating means 155) is determined according to the alcohol concentration. For example, the fuel F is easily heated by the heating means 55 as its alcohol concentration increases.

  As described above, the fuel injection control device for an internal combustion engine according to the present invention is useful as a technique for effectively improving the low-temperature startability by the heated fuel.

It is a figure shown about an example of the internal combustion engine used as the application object of the fuel-injection control apparatus of the internal combustion engine which concerns on this invention. It is a figure shown about the state in the fuel delivery pipe for in-line 4 cylinder internal combustion engines before the injection start. It is a figure shown about the state in the fuel delivery pipe of Example 1 for in-line 4 cylinder internal combustion engines at the time of the injection start of the fuel of # 1 cylinder which is a 1st fuel injection cylinder. It is a figure shown about the state in the fuel delivery pipe of Example 1 for inline 4 cylinder internal combustion engines at the time of completion | finish of fuel injection of # 1 cylinder which is a 1st fuel injection cylinder. 3 is a flowchart illustrating a control operation at a low temperature start by the fuel injection control device of Embodiment 1. It is a figure shown about the state in the fuel delivery pipe for V type 6 cylinder internal combustion engines before the injection start. FIG. 5 is a diagram illustrating a state in the fuel delivery pipe of the first embodiment for the V-type six-cylinder internal combustion engine at the start of fuel injection of the # 5 cylinder that is the first fuel injection cylinder. FIG. 5 is a diagram showing a state in the fuel delivery pipe of the first embodiment for the V-type six-cylinder internal combustion engine at the end of fuel injection of the # 5 cylinder that is the first fuel injection cylinder. It is a flowchart explaining the control action at the time of the low temperature start by the fuel-injection control apparatus of Example 2. FIG. It is a figure shown about the state in the fuel delivery pipe of Example 2 for the inline 4-cylinder internal combustion engine at the time of completion | finish of fuel injection of # 1 cylinder which is a 1st fuel injection cylinder. It is a figure shown about the state in the fuel delivery pipe of Example 2 for in-line 4 cylinder internal combustion engines at the time of completion | finish of fuel injection of # 2 cylinder which is a 1st fuel injection cylinder. It is a figure shown about the state in the fuel delivery pipe of Example 2 for the inline 4-cylinder internal combustion engine at the time of completion | finish of fuel injection of # 3 cylinder which is a 1st fuel injection cylinder. It is a figure shown about the state in the fuel delivery pipe of Example 2 for in-line 4 cylinder internal combustion engines at the time of completion | finish of fuel injection of # 4 cylinder which is a 1st fuel injection cylinder.

Explanation of symbols

1 Electronic Control Unit 11b Intake Port 16 Crank Angle Sensor 41 Fuel Tank 50 Fuel Supply Device 51 Fuel Passage 52 Feed Pump (Fuel Pump)
53, 153 Fuel delivery pipe 54 Fuel injection valve 54a First fuel injection valve 54b Second fuel injection valve 54c Third fuel injection valve 54d Fourth fuel injection valve 55, 155 Heating means 154a First fuel injection valve 154b Second fuel injection Valve 154c third fuel injection valve 154d fourth fuel injection valve 154e fifth fuel injection valve 154f sixth fuel injection valve CC combustion chamber F fuel (heated fuel, non-heated fuel)

Claims (3)

In a fuel injection control device for an internal combustion engine capable of injecting fuel heated after delivery from a fuel pump into a fuel injection valve for each cylinder connected to a fuel delivery pipe,
A fuel injection control device for an internal combustion engine, comprising fuel pump control means for stopping the driving of the fuel pump until the heated fuel in the fuel delivery pipe becomes a predetermined amount or less. In a fuel injection control device for an internal combustion engine capable of injecting fuel heated after delivery from a fuel pump into a fuel injection valve for each cylinder connected to a fuel delivery pipe,
The first fuel injection cylinder specifying means for specifying the first fuel injection cylinder to which fuel is first supplied at the time of engine start and the non-heated fuel supplied into the fuel delivery pipe will not lower the low temperature startability. , the internal combustion engine, characterized in that a, a fuel pump control means for reduction of the fuel delivery amount of the fuel pump in response to the ejection order of the first fuel injection cylinder and the fuel injection valves, which are the specific Fuel injection control device. In a fuel injection control device for an internal combustion engine capable of injecting fuel heated after delivery from a fuel pump into a fuel injection valve for each cylinder connected to a fuel delivery pipe,
First fuel injection cylinder specifying means for specifying a first fuel injection cylinder to which fuel is first supplied at the time of engine start, and the injection order of the specified first fuel injection cylinder and each fuel injection valve The non-heated fuel injection valve specifying means for specifying the fuel injection valve in which the non-heated fuel supplied into the fuel delivery pipe is injected , and the earlier the injection timing of the non-heated fuel by the specified fuel injection valve comes the fuel injection control apparatus for internal combustion engine you characterized by providing a fuel pump control means for gradually was reduced fuel delivery amount of the fuel pump, the.

Images