JP2006322443A - Fuel injection controller for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set optimum fuel injection quantity preventing adverse effects on an operating condition of an engine, even when a series of operations of rapidly opening a throttle valve from a predetermined throttle opening and then rapidly closing the throttle valve occurs within an extremely short time in one combustion cycle of the internal combustion engine. <P>SOLUTION: When the series of operations of rapidly opening the throttle valve 11 from the predetermined throttle opening and then rapidly closing the throttle valve 11 occurs within a predetermined time in one combustion cycle of the internal combustion engine 1 after completion of stroke determination, supply of fuel injection quantity calculated based on various parameters including a throttle opening TA and performed by an injector 5 in accordance with a crank angle signal SCRANK is compulsorily stopped. At this time, in the case where suction air quantity overlaps with at least one-third of an intake stroke period in one combustion cycle of the internal combustion engine 1, the compulsory stop of the supply of the fuel injection quantity is released. Due to this, the fuel injection quantity can be appropriately corrected and the operating condition of the internal combustion engine 1 can be favorably maintained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel injection control device for an internal combustion engine that calculates a fuel injection amount in a combustion cycle from a crank angle signal detected corresponding to an angular position associated with rotation of a crankshaft of the internal combustion engine and performs fuel injection control. Is.

  In general, in an independent intake internal combustion engine, a basic fuel injection amount is set based on an intake pressure, a throttle opening, an engine rotation speed, and the like, and this basic fuel injection amount is determined based on a cooling water temperature, an intake air temperature, an atmospheric pressure, and a transmission gear. The final fuel injection amount is calculated by correction based on various parameters such as the position. Further, fuel cut control is performed in which the fuel injection amount is changed or stopped in accordance with various operation parameters such as engine speed, vehicle speed, and throttle opening change amount.

As a prior art document related to this, one disclosed in Japanese Patent Laid-Open No. 4-81537 is known. This technique shows a technique for reducing or cutting the fuel supply amount from a steady value for a predetermined time when deceleration is detected within a predetermined time after acceleration correction.
JP-A-4-81537 (first page to second page)

  By the way, in the above-mentioned case, when a series of operations such as opening the throttle valve suddenly from a predetermined throttle opening and then closing suddenly occurs within an extremely short time such that it is within one combustion cycle of the internal combustion engine. Assuming that the processing capability of the CPU in the electronic control unit at that time is taken into consideration, it cannot be considered at all. Therefore, in such a case, it is not possible to cope with the overrich caused by the asynchronous fuel injection according to the change in the throttle opening at the time of the first sudden opening of the throttle valve due to the driver's acceleration request. The possibility of causing a drop in rotational speed, engine stall, etc. is assumed.

  Further, even when a series of operations such as suddenly closing the throttle valve after opening it from a predetermined throttle opening occurs within an extremely short time such that it is within one combustion cycle of the internal combustion engine, At this time, it has been clarified by experiments and research by the inventor that the amount of asynchronous fuel injection may not be a cause of over-rich, and if the fuel supply amount is reduced or cut uniformly, the operation of the internal combustion engine is reversed. The possibility of adversely affecting the condition is also envisaged.

  Therefore, the present invention has been made to eliminate the predictability of such a problem, and a series of operations in which the throttle valve is suddenly opened from a predetermined throttle opening and then suddenly closed within one combustion cycle of the internal combustion engine is extremely short. An object of the present invention is to provide a fuel injection control device for an internal combustion engine that can set an optimal fuel injection amount without adversely affecting the operating state of the internal combustion engine even if it occurs within the time.

  According to the fuel injection control apparatus for an internal combustion engine of claim 1, one combustion cycle after completion of stroke determination by the stroke determination means based on the crank angle signal detected by the crank angle detection means as the crankshaft of the internal combustion engine rotates. The fuel injection amount calculated from various parameters including the throttle opening detected by the throttle opening detection means by the fuel injection control means, and the fuel injection amount supplied from the fuel injection valve corresponding to the crank angle signal is the throttle valve When a series of operations that are suddenly opened after a predetermined throttle opening occurs within a short time within a predetermined time, there is a possibility of over-riching, so the fuel injection correction means forcibly stops In addition, the intake air amount due to a series of operations of the throttle valve at this time is small in the intake stroke period in one combustion cycle of the internal combustion engine. Both when according to (1/3), because becomes necessary to maintain the operating state of the internal combustion engine, forcibly stopping the supply of the fuel injection quantity is released. As a result, even when a series of operations in which the throttle valve is suddenly opened from a predetermined throttle opening and then suddenly closed occurs within an extremely short period of time within one combustion cycle of the internal combustion engine, An optimal fuel injection amount that does not adversely affect the engine is set.

  In the fuel injection correction means in the fuel injection control device for an internal combustion engine according to claim 2, when the absolute value of the amount of change in the throttle opening in a series of operations of the throttle valve is as large as 0.098 [° / ms] or more, it opens rapidly. Alternatively, it can be surely determined that a series of operations of the throttle valve has occurred by determining the sudden closing.

  In the fuel injection correction means in the fuel injection control apparatus for an internal combustion engine according to claim 3, the execution condition is when a series of operations of the throttle valve occur within a short time within 100 [ms] as a predetermined time. Thus, an appropriate and optimal fuel injection amount is set for the internal combustion engine.

  In the fuel injection correction means in the fuel injection control device for an internal combustion engine according to claim 4, the execution condition is when the throttle valve is in a closed state from a predetermined throttle opening degree at the time of sudden closing in a series of operations of the throttle valve. An accurate and optimal fuel injection amount is set for the internal combustion engine.

  In the fuel injection control device for an internal combustion engine according to claim 5, the internal combustion engine is a four-cycle single cylinder or a four-cycle multiple cylinder of independent intake. In an internal combustion engine composed of these four-cycle single cylinder or four cylinders with independent intake, even if a series of throttle valve operations occur within one combustion cycle, the optimum fuel injection amount corresponding to the cylinder is set. The operating state of the internal combustion engine is maintained well.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples.

  FIG. 1 is a schematic configuration diagram showing an internal combustion engine and its peripheral devices to which a fuel injection control device for an internal combustion engine according to an embodiment of the present invention is applied.

  In FIG. 1, reference numeral 1 denotes an internal combustion engine composed of four-cycle single cylinders. Air from an air cleaner 3 is introduced into an intake passage 2 of the internal combustion engine 1. A throttle valve 11 that is opened and closed in conjunction with the accelerator operation amount of the driver (driver) is disposed in the intake passage 2. By opening and closing the throttle valve 11, the intake air amount to the intake passage 2 is adjusted. Further, the fuel pressure-fed by a fuel pump (not shown) and regulated through a pressure regulator according to the intake air amount is disposed in the intake passage 2 in the vicinity of the intake port 4 of the internal combustion engine 1. The fuel is injected from an injector (fuel injection valve) 5. Then, an air-fuel mixture composed of a predetermined fuel injection amount and intake air amount is sucked into the combustion chamber 7 via the intake valve 6.

  A throttle opening sensor 21 for detecting a throttle opening TA corresponding to an accelerator operation amount or the like is disposed in the throttle valve 11 in the intake passage 2. An intake pressure sensor 22 that detects the intake pressure PM in the intake passage 2 is disposed on the downstream side of the throttle valve 11. The internal combustion engine 1 is provided with a water temperature sensor 23 for detecting the cooling water temperature THW. Further, a crank rotor 24 is fixed to the crankshaft 13 of the internal combustion engine 1, and a crank angle sensor 25 for detecting a crank angle signal SCRANK generated as the crank rotor 24 rotates is disposed. .

  Here, the crank rotor 24 has a number of teeth (24-2) in which two consecutive portions among 24 tooth portions having a plurality of equal angles are missing. The position of the missing tooth portion is known by the difference in the pulse generation interval of the crank angle signal SCRANK output from the crank angle sensor 25 in accordance with the rotation of the crank rotor 24 fixed to the crankshaft 13. The engine speed NE of the internal combustion engine 1 is calculated based on the pulse generation interval of the crank angle signal SCRANK detected by the crank angle sensor 25.

  A spark plug 14 is disposed toward the combustion chamber 7 of the internal combustion engine 1. The spark plug 14 receives a high signal from an ignition coil 15 based on an ignition command signal output from an ECU (Electronic Control Unit) 30 described later in synchronization with a crank angle signal SCRANK detected by a crank angle sensor 25. A voltage is applied, and ignition combustion is performed on the air-fuel mixture in the combustion chamber 7. In this way, the air-fuel mixture in the combustion chamber 7 is combusted (expanded) to obtain driving force, and the exhaust gas after combustion is led out from the exhaust manifold to the exhaust passage 9 via the exhaust valve 8 and discharged to the outside. The

  The ECU 30 includes a CPU 31 as a central processing unit that executes various known arithmetic processes, a ROM 32 that stores control programs and control maps, a RAM 33 that stores various data, a B / U (backup) RAM 34, an input / output circuit 35, It is configured as a logical operation circuit composed of a bus line 36 etc. for connecting them. The ECU 30 receives a throttle opening TA from the throttle opening sensor 21, an intake pressure PM from the intake pressure sensor 22, a cooling water temperature THW from the water temperature sensor 23, a crank angle signal SCRANK from the crank angle sensor 25, and the like. ing. Based on the output signals from the ECU 30 based on these various sensor information, the injector 5 related to the fuel injection timing and the fuel injection amount, the spark plug 14 related to the ignition timing, the ignition coil 15 and the like are appropriately controlled.

  Next, referring to the time chart shown in FIG. 2, the throttle valve 11 is suddenly opened from the predetermined throttle opening with respect to the crank angle signal counter NNUM position (stroke position) after completion of the stroke determination accompanying the generation of the crank angle signal SCRANK. After that, a transition state of the throttle opening degree TA [°] when a series of operations for sudden closing occurs will be described. The transition state of the throttle opening TA with respect to the crank angle signal counter NNUM position in FIG. 2 is merely an example.

  2, in one combustion cycle of 720 [° CA (Crank Angle)] consisting of four cycles (intake stroke → compression stroke → combustion (expansion) stroke → exhaust stroke), for example, detected by the intake pressure sensor 22 The crank angle signal counter is assumed that the intake air pressure PM is almost atmospheric pressure and that the first crank angle signal SCRANK after the tooth missing portion is the reference crank angle position in the rotation direction of the crankshaft 13. NNUM is set to “0 (zero)”, and it is assumed that it is the start time of the exhaust stroke, and the stroke determination is completed.

  Thereafter, the crank angle signal counter NNUM is incremented by “+1” every 15 [° CA] when the crank angle signal SCRANK is generated. The pulse generation interval of the crank angle signal SCRANK at the missing tooth portion is 45 [° CA]. Then, the crank angle signal counter NNUM is reset to “0” for every combustion cycle of 720 [° CA], which is the generation time point of the first crank angle signal SCRANK in the exhaust stroke.

  After the stroke determination is completed, “0” to “11” are the exhaust stroke, “12” to “21” are the intake stroke, and “24” to “35” based on the crank angle signal counter NNUM accompanying the rotation of the crankshaft 1. Is the compression stroke, and “36” to “45” are the stroke (expansion) stroke and stroke management, respectively. Since the crank rotor 24 is composed of (24-2) teeth and two consecutive locations are missing teeth, “22”, “23”, “46”, and “47” are missing numbers. .

  Next, based on the flowchart of FIG. 3 showing the processing procedure of the fuel injection correction control in the fuel injection control by the CPU 31 in the ECU 30 used in the ignition control device of the internal combustion engine according to one embodiment of the present invention, FIG. Will be described with reference to FIG. The fuel injection correction control in the present embodiment is the fuel injection amount by the synchronous fuel injection control or the asynchronous fuel injection control supplied from the injector 5 within one combustion cycle of the internal combustion engine 1. Control that forcibly stops or cancels the forcible stop corresponding to a series of operations that are suddenly opened after opening from the opening TA. This fuel injection correction control routine is repeatedly executed by the CPU 31 every 5 [ms].

  In FIG. 3, first, in step S101, it is determined whether it is a start time. When the determination condition of step S101 is satisfied, that is, when the internal combustion engine 1 is started by cranking, this routine is terminated without doing anything. On the other hand, if the determination condition of step S101 is not satisfied, that is, a predetermined time (for example, 1520 [ms]) has elapsed after the start of the internal combustion engine 1, and the start of the internal combustion engine 1 is completed, the step The process proceeds to S102, and it is determined whether the stroke determination is completed. When the determination condition of step S102 is not satisfied, that is, when the stroke determination in one combustion cycle of the internal combustion engine 1 is not completed, this routine is finished without doing anything. As other preconditions, when the engine rotational speed NE of the internal combustion engine 1 is less than a predetermined rotational speed (for example, 1800 [rpm]), and naturally, the throttle opening sensor 21 is normal. And so on.

  On the other hand, when the determination condition of step S102 is satisfied, that is, as described above, the stroke determination in one combustion cycle of the internal combustion engine 1 is completed, and when all the above preconditions are satisfied, the process proceeds to step S103. The throttle opening TA at that time is read. Next, the process proceeds to step S104, and the difference between the current throttle opening TA and the previous throttle opening TAO 5 [ms] is calculated as the throttle opening change amount ΔTA.

  Next, the process proceeds to step S105, where the throttle opening change amount ΔTA calculated in step S104 exceeds the predetermined throttle opening change amount α [° / ms], and the throttle opening degree read in step S103. After TA exceeds a predetermined throttle opening β [°], it is determined whether it is within a predetermined time γ [ms]. Specifically, the throttle opening change amount ΔTA is, for example, 0.49 [°] or more in 5 [ms], that is, the rising slope of the throttle opening TA is 0.098 [° / ms]. After the condition that the throttle opening TA exceeds the predetermined throttle opening β, for example, exceeds 44.92 [°], whether the predetermined time γ is within 100 [ms] is determined. The

  When the determination condition of step S105 is satisfied, that is, when the throttle opening change amount ΔTA is larger than 0.098 [° / ms], the throttle valve 11 is suddenly opened and the throttle opening TA is 44.92. When it is larger than [°], it is a large movement toward the opening side of the throttle valve 11, and after these conditions are established, when it is within a predetermined time 100 [ms], it is understood that these movements are immediately after the occurrence. Therefore, the process proceeds to step S106.

  In step S106, the throttle opening change amount ΔTA calculated in step S104 is less than the predetermined throttle opening change amount X [° / ms], and the throttle opening TA read in step S103 is the predetermined throttle opening change amount. It is determined whether it is less than Y and the crank angle signal counter NNUM is “15” or more and “21” or less. Specifically, the throttle opening change amount ΔTA is, for example, less than −0.49 [° / ms] during 5 [ms], that is, the falling slope of the throttle opening TA is −0.098 [ Less than [° / ms], and the throttle opening TA is a predetermined throttle opening Y, for example, less than 43.95 [°], and the crank angle signal counter NNUM is “15” or more and “21” or less. Is determined.

  When the determination condition in step S106 is not satisfied even once, that is, the throttle opening change amount ΔTA is greater than or equal to the predetermined throttle opening change amount X [° / ms], or the throttle opening TA is the predetermined throttle opening Y [ If the crank angle signal counter NNUM is not less than “15” and not more than “21”, the process proceeds to step S107. In step S107, after stopping or prohibiting synchronous fuel injection control and asynchronous fuel injection control, which will be described later, this routine is terminated.

  On the other hand, the determination condition of step S105 is not satisfied, that is, the throttle opening change amount ΔTA is as small as a predetermined throttle opening change amount α [° / ms] or less, or the throttle opening TA is less than a predetermined throttle opening β. Both conditions are not satisfied, or the throttle opening change amount ΔTA is larger than the predetermined throttle opening change amount α [° / ms], and the throttle opening TA is the predetermined throttle opening β [° ], The routine ends without doing anything when the time exceeds a predetermined time γ [ms].

  Further, when the determination condition of step S106 is satisfied, that is, when the throttle valve change amount ΔTA is a small value of less than −0.098 [° / ms], the throttle valve 11 is suddenly closed, and the throttle opening TA is What is a large movement toward the closing side of the throttle valve 11 which is smaller than 43.95 [°] and the crank angle signal counter NNUM at this time is within the range of “15” or more and “21” or less? This routine is terminated without doing anything. That is, the synchronous fuel injection control and the asynchronous fuel injection control that are executed when the determination condition in step S106 is not satisfied are not stopped or prohibited, and fuel injection is continuously executed. Therefore, the forced stop of the fuel injection amount supply is released.

  When the crank angle signal counter NNUM is in the range of “15” or more and “21” or less among the determination conditions in step S106, the time chart of FIG. This is the period from the time when / 3 is passed to the end of the intake stroke.

  Therefore, in this embodiment, a series of operations in which the throttle valve 11 is suddenly opened from a predetermined throttle opening and then rapidly closed (that is, the throttle opening TA exceeds the predetermined throttle opening β and the throttle opening change amount ΔTA is set). After the rapid opening operation of the throttle valve 11 such that the throttle valve opening change amount α exceeds the predetermined throttle opening change amount α, the throttle opening change amount ΔTA falls below the predetermined throttle opening change amount X and the throttle opening within the predetermined time γ. In the state in which the throttle valve 11 is suddenly closed such that the degree TA falls below the predetermined opening Y), the timing at which the throttle valve 11 is suddenly closed is “15” or more when the crank angle signal counter NNUM is “15” or more. 21 ”or less (ie, when step S106 is“ YES ”), the throttle valve 11 It is assumed that intake of the intake air amount by the series of operations takes at least 1/3 or more of the intake stroke period in one combustion cycle of the internal combustion engine 1.

  Then, as explained in the flowchart of FIG. 3, a series of operations of suddenly closing the throttle valve 11 from a predetermined throttle opening degree and then rapidly closing occurs at a predetermined time, and the crank angle signal counter NNUM is “15” or more. When it is not within the range of “21” or less, even if a series of operations of the throttle valve 11 occurs, it does not overlap with the intake stroke so much that the intake of the intake air amount into the combustion chamber 7 is substantially reduced. It is considered that it was not. Accordingly, the process proceeds to step S107, and the synchronous fuel injection control and the asynchronous fuel injection control are stopped or prohibited.

  On the other hand, a period from when a series of operations of the throttle valve 11 occurs and after the throttle valve 11 is suddenly closed until 1/3 has elapsed after the start of the intake stroke (the crank angle signal counter NNUM is “ If it is within the range of “15” or more and “21” or less), step S106 is established, and this routine is terminated without doing anything. At this time, it is considered that a further intake air amount is sucked into the combustion chamber 7 by overlapping a series of operations of the throttle valve 11 with the intake stroke. Therefore, the forced stop of the fuel injection amount supply due to the suspension or prohibition of the synchronous fuel injection control and the asynchronous fuel injection control as in step S107 is released, and the fuel injection is continued.

  Next, the processing procedure of the synchronous fuel injection control in the fuel injection control by the CPU 31 in the ECU 30 used in the ignition control device of the internal combustion engine according to one embodiment of the present invention will be described based on the flowchart of FIG. This synchronous fuel injection control routine is repeatedly executed by the CPU 31 when the crank angle signal counter NNUM for each 720 [° CA] shown in FIG.

  In FIG. 4, first, in step S201, the throttle opening degree TA is read. Next, the routine proceeds to step S202, where the engine speed NE of the internal combustion engine 1 based on the pulse generation interval of the crank angle signal SCRANK detected by the crank angle sensor 25 is read. Next, the process proceeds to step S203, and the fuel injection timing is calculated based on a fuel injection timing map (not shown) using the throttle opening degree TA read in step S201 and the engine speed NE read in step S202 as parameters.

  Next, the process proceeds to step S204, where it is determined whether it is the fuel injection timing calculated in step S203. If the determination condition of step S204 is satisfied, that is, if it is the fuel injection timing at this time, the routine proceeds to step S205, where synchronous fuel injection control is started. On the other hand, if the determination condition of step S204 is not satisfied, that is, if it is not the fuel injection timing, this routine is terminated without doing anything.

  As is well known, the fuel injection amount in the synchronous fuel injection control is set by the intake pressure PM, the throttle opening degree TA, the engine rotational speed NE, etc. This basic fuel injection amount is finally calculated by correcting it based on various parameters such as intake air temperature, atmospheric pressure, transmission gear position and the like in addition to the coolant temperature THW.

  Next, the processing procedure of asynchronous fuel injection control in the fuel injection control by the CPU 31 in the ECU 30 used in the ignition control device of the internal combustion engine according to one embodiment of the present invention will be described based on the flowchart of FIG. This asynchronous fuel injection control routine is repeatedly executed by the CPU 31 every 5 [ms].

  In FIG. 5, first, in step S301, the throttle opening degree TA is read. Next, the process proceeds to step S302, and the difference between the throttle opening TA at this time and the throttle opening TAO 5 [ms] before is calculated as the throttle opening change amount ΔTA. Next, the process proceeds to step S303, where it is determined whether the throttle opening change amount ΔTA calculated in step S302 exceeds a predetermined throttle opening change amount η [° / ms].

  When the determination condition of step S303 is satisfied, that is, when the throttle opening change amount ΔTA is larger than the predetermined throttle opening change amount η [° / ms] at this time, the process proceeds to step S304 and within one combustion cycle of the internal combustion engine 1. Asynchronous fuel injection control is started on the assumption that it is necessary to supply an asynchronous fuel injection amount from the injector 5 in response to an operation in which the throttle valve 11 is suddenly opened from the predetermined throttle opening TA. On the other hand, when the determination condition of step S303 is not satisfied, that is, when the throttle opening change amount ΔTA is as small as the predetermined throttle opening change amount η [° / ms] or less, this routine is terminated without doing anything.

  As is well known, the fuel injection amount in the asynchronous fuel injection control is set based on the engine speed NE at this time in a routine not shown, and the fuel injection amount at the asynchronous time is It is finally calculated by correcting it based on various parameters such as the intake air temperature in addition to the throttle opening change amount ΔTA and the coolant temperature THW.

  As described above, the fuel injection control device for the internal combustion engine of the present embodiment has a throttle opening as a throttle opening detecting means for detecting the throttle opening TA of the throttle valve 11 disposed in the intake passage 2 of the internal combustion engine 1. A stroke determination is made based on the sensor 21, a crank angle sensor 25 as a crank angle detection means for detecting a crank angle signal SCRANK accompanying the rotation of the crankshaft 13 of the internal combustion engine 1, and a crank angle signal SCRANK detected by the crank angle sensor 25. Is calculated based on various parameters (such as engine speed NE) including the throttle opening TA within one combustion cycle of the internal combustion engine 1 defined by the stroke determination means. An injector disposed in the intake passage 2 of the internal combustion engine 1 corresponding to the crank angle signal SCRANK. In one combustion cycle of the internal combustion engine 1 defined by the fuel injection control means (ECU 30) supplied from the fuel injection valve (5) and the stroke determination means, the throttle valve 11 is suddenly opened from a predetermined throttle opening. Then, when a series of operations for sudden closing occurs within a predetermined time, the synchronous fuel injection control and the asynchronous fuel injection control are stopped or prohibited in order to forcibly stop the supply of the fuel injection amount by the fuel injection control means. When the intake air amount due to the series of operations of the throttle valve 11 at this time takes at least (1/3) of the intake stroke period within one combustion cycle of the internal combustion engine 1, the fuel injection amount of the fuel injection control means is reduced. And a fuel injection correction unit that is achieved by the ECU 30 that cancels the forced stop of the supply. Further, the fuel injection correction means achieved by the ECU 30 of the fuel injection control device for the internal combustion engine of the present embodiment is such that the absolute value of the throttle opening change ΔTA in a series of operations of the throttle valve 11 is 0.098 [°. / Ms] or more, it is determined to be suddenly open or suddenly closed. The internal combustion engine 1 is a four-cycle single cylinder.

  That is, in one combustion cycle after the stroke determination of the internal combustion engine 1 is completed, the absolute value of the change amount ΔTA of the throttle opening when the throttle valve 11 is opened or closed from the predetermined throttle opening is 0.098 [ When the series of operations that are determined to be suddenly closed after sudden opening occurs within a predetermined time, the injector corresponding to the crank angle signal SCRANK is calculated based on various parameters including the throttle opening TA. The supply of the fuel injection amount from 5 is forcibly stopped.

  However, the forced stop of the supply of the fuel injection amount from the injector 5 is not uniformly performed, and the intake air amount by a series of operations of the throttle valve 11 at this time is equal to one combustion cycle of the internal combustion engine 1. When it takes at least (1/3) of the intake stroke period, the air-fuel mixture having a predetermined air-fuel ratio is actually introduced into the cylinder and becomes necessary for maintaining the operating state of the internal combustion engine 1. The forcible stop of supply is released.

  At this time, when the series of operations of the throttle valve 11 occurs, any of the intake stroke, compression stroke, combustion (expansion) stroke, and exhaust stroke as one combustion cycle of the internal combustion engine 1 How much the intake air amount thus takes in the intake stroke period is set in advance according to the crank angle signal counter NNUM according to the actual machine. As described above, in this embodiment, when the crank angle signal counter NNUM is within the range of “15” or more and “21” or less, when the end point of the series of operations of the throttle valve 11 is entered, the intake air amount is 1 It is said that it takes at least 1/3 or more of the intake stroke period in the combustion cycle.

  In this way, every time a series of operations of the throttle valve 11 occur within a predetermined time, the forced stop or release of the fuel injection amount is set in consideration of the influence on the internal combustion engine 1. The fuel injection amount is accurately corrected, and as a result, the operating state of the internal combustion engine 1 can be maintained well.

  Further, the fuel injection correction means achieved by the ECU 30 of the fuel injection control device for the internal combustion engine according to the present embodiment has an execution condition when a series of operations of the throttle valve 11 is within 100 [ms]. is there. Furthermore, the fuel injection correction means achieved by the ECU 30 of the fuel injection control device for the internal combustion engine of the present embodiment is when the throttle valve is in a closed state from a predetermined throttle opening degree at the time of sudden closing in a series of operations. Is an execution condition.

  That is, when a series of operations in which the throttle valve 11 is suddenly opened from a predetermined throttle opening and then rapidly closed occurs within an extremely short time within 100 [ms] within one combustion cycle of the internal combustion engine 1, When it is assumed that the operating condition of the internal combustion engine 1 may be adversely affected by the execution condition being when the throttle valve 11 is in the closed state from the predetermined throttle opening degree at the time of sudden closing in a series of operations. In addition, the fuel injection correction control can be performed accurately.

  In short, this embodiment will be described in more detail. When the period of a series of operations by the sudden opening and closing of the throttle valve 11 occupies 2/3 or more of the entire intake stroke period (that is, In the period from the start of the intake stroke to 1/3, when the sudden closing of the throttle valve 11 is completed), the intake air amount into the combustion chamber 7 is not substantially increased by the series of operations. Therefore, the synchronous fuel injection control and the asynchronous fuel injection control are stopped or prohibited in order to forcibly stop the supply of the fuel injection amount. However, when the period in which the series of operations of the throttle valve 11 is completed is smaller than 1/3 during the entire intake stroke period (that is, after 2/3 from the start of the intake stroke, the throttle valve 11 suddenly stops). When the closing is completed), it is considered that the intake air amount has further increased to the combustion chamber 7 due to the series of operations, and the above-mentioned forced stop of the fuel injection amount supply is released. The fuel injection is to be continued.

  As a result, it is possible to control the fuel injection amount corresponding to the actual air amount sucked into the cylinder even for a sudden change in the opening degree of the throttle valve 11 in a very short time within one combustion cycle. Problems such as over-rich described in the prior art are eliminated, and adverse effects on the operating state of the internal combustion engine 1 can be prevented.

  Next, based on the flowchart of FIG. 6 which shows the modification of the process sequence of the fuel-injection correction control in the fuel-injection control by CPU31 in ECU30 used with the fuel-injection control apparatus of the internal combustion engine concerning one Example of this invention. A description will be given with reference to FIG. The fuel injection correction control routine is repeatedly executed by the CPU 31 every 5 [ms].

  In FIG. 6, steps S401 to S405 correspond to steps S101 to S105 in the above embodiment, and thus detailed description thereof is omitted. In step S406, as in step S106, it is determined whether the conditions of the throttle opening change amount ΔTA and the throttle opening TA are satisfied. Further, it is determined whether the crank angle signal counter NNUM is within the range of “11” or more and “21” or less. That is, it is determined whether or not it is in the inhalation stroke. Then, when the determination condition of step S406 is satisfied, the process proceeds to step S407, where the crank angle signal counter NNUM in the determination condition of step S406 is “11” or more and “21” or less, and further, the crank angle signal counter NNUM. Is “15” or more and “21” or less (see FIG. 2).

  On the other hand, the determination condition in step S406 is not satisfied, that is, as in step S106, the condition is not satisfied in any one of the throttle opening change amount ΔTA and the throttle opening TA, or the crank angle signal counter NNUM is When the throttle valve 11 is not within the range of “11” or more and “21” or less, even if there is a series of operations from sudden opening to sudden closing within a predetermined time, the intake air to the combustion chamber 7 based on that operation Since it is considered that the amount of intake is substantially absent, the process proceeds to step S408, and after the above-described synchronous fuel injection control and asynchronous fuel injection control are stopped or prohibited as the fuel injection correction control, this routine is executed. finish.

  Next, in step S407, when the determination condition is not satisfied, that is, when the crank angle signal counter is not in the range of “15” or more and “21” or less, the process proceeds to step S409, and only the above-described asynchronous fuel injection control is performed. This routine is terminated after cancellation or prohibition is executed. On the other hand, if the determination condition in step S407 is satisfied even once, this routine is terminated without doing anything. At this time, a series of operations of the throttle valve 11 overlap with the intake stroke, so that it is considered that the intake air amount is further sucked into the combustion chamber 7. Therefore, the fuel injection is continued without stopping the supply of the fuel injection amount by stopping or prohibiting the synchronous fuel injection control and the asynchronous fuel injection control.

  In step S409, only the asynchronous fuel injection control is stopped or prohibited. At this fuel injection timing, the end point of the series of operations of the throttle valve 11 takes 1/3 from the start of the intake stroke. In this case, since the intake air amount into the combustion chamber 7 has not been sucked in at all, the asynchronous fuel injection control is stopped or prohibited, but the synchronous fuel injection control must also be stopped or prohibited. It is based on the judgment that there is no.

  As described above, the fuel injection control device for the internal combustion engine of the present modification has a throttle opening as a throttle opening detecting means for detecting the throttle opening TA of the throttle valve 11 disposed in the intake passage 2 of the internal combustion engine 1. A stroke determination is made based on the sensor 21, a crank angle sensor 25 as a crank angle detection means for detecting a crank angle signal SCRANK accompanying the rotation of the crankshaft 13 of the internal combustion engine 1, and a crank angle signal SCRANK detected by the crank angle sensor 25. Is calculated based on various parameters (such as engine speed NE) including the throttle opening TA within one combustion cycle of the internal combustion engine 1 defined by the stroke determination means. An injector disposed in the intake passage 2 of the internal combustion engine 1 corresponding to the crank angle signal SCRANK. The fuel injection control means achieved by the ECU 30 supplied from the engine and the series in which the throttle valve 11 is suddenly opened from a predetermined throttle opening and then suddenly closed within one combustion cycle of the internal combustion engine 1 defined by the stroke determination means. When the above operation occurs within a predetermined time, the synchronous fuel injection control and the asynchronous fuel injection control are stopped or prohibited to forcibly stop the supply of the fuel injection amount by the fuel injection control means, or only the asynchronous fuel injection control is performed. When the intake air amount due to a series of operations of the throttle valve 11 at this time takes at least (1/3) of the intake stroke period within one combustion cycle of the internal combustion engine 1, the fuel injection control is performed. And a fuel injection correcting means that is achieved by the ECU 30 for releasing the forced stop of the supply of the fuel injection amount by the means. It is.

  That is, as in the above embodiment, a series of operations that are determined to be suddenly closed after the throttle valve 11 is suddenly opened from a predetermined throttle opening within one combustion cycle after completion of stroke determination of the internal combustion engine 1 are performed within a predetermined time. If this happens, the supply of the fuel injection amount from the injector 5 calculated based on various parameters including the throttle opening TA and corresponding to the crank angle signal SCRANK is forcibly stopped.

  However, the forced stop of the supply of the fuel injection amount from the injector 5 is not uniformly performed, and the intake air amount by a series of operations of the throttle valve 11 at this time is equal to one combustion cycle of the internal combustion engine 1. When it takes at least (1/3) of the intake stroke period, the air-fuel mixture having a predetermined air-fuel ratio is actually introduced into the cylinder and becomes necessary for maintaining the operating state of the internal combustion engine 1. There will be no compulsory stop of supply.

  In this way, whenever the series of operations of the throttle valve 11 occurs within a predetermined time, if the end point of the series of operations is between 1/3 and the start of the intake stroke, only the asynchronous fuel injection control is performed. If the synchronous fuel injection control is executed after being stopped or prohibited and between 1/3 of the intake stroke and the end of the intake stroke, the synchronous fuel injection control and the asynchronous fuel injection control are not executed. Fuel injection control is executed. Further, even if a series of operations of the throttle valve 11 occur, if it is other than the intake stroke, the supply of the fuel injection amount by the synchronous fuel injection control and the asynchronous fuel injection control is forcibly stopped. Therefore, depending on whether the forced stop of the fuel injection amount supply or the release thereof in the fuel injection correction control in the fuel injection control at that time is the synchronous fuel injection control or the asynchronous fuel injection control, the internal combustion engine 1 is affected. By setting in consideration, the fuel injection amount is finely and accurately corrected, and as a result, the operating state of the internal combustion engine 1 can be maintained well.

  In the above-described embodiments and modifications, the case where the internal combustion engine 1 is a four-cycle single cylinder has been described. However, the present invention is not limited to this. Even in the case of independent-intake four-cycle multiple cylinders that independently supply the intake air amount, similar operations and effects can be expected by performing similar fuel injection correction control for each cylinder.

FIG. 1 is a schematic configuration diagram showing an internal combustion engine and its peripheral devices to which a fuel injection control device for an internal combustion engine according to an embodiment of the present invention is applied. FIG. 2 is a time chart showing a transition state of the throttle opening when a series of operations of the throttle valve occur with respect to the crank angle signal counter position after completion of the stroke determination accompanying the generation of the crank angle signal in the internal combustion engine of FIG. is there. FIG. 3 is a flowchart showing the procedure of the fuel injection correction control in the fuel injection control by the CPU in the ECU used in the fuel injection control device for the internal combustion engine according to one embodiment of the present invention. FIG. 4 is a flowchart showing a synchronous fuel injection process in the fuel injection correction control of FIG. FIG. 5 is a flowchart showing an asynchronous fuel injection process in the fuel injection correction control of FIG. FIG. 6 is a flowchart showing a modification of the processing procedure of the fuel injection correction control in the fuel injection control by the CPU in the ECU used in the fuel injection control device of the internal combustion engine according to one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Intake passage 5 Injector (fuel injection valve)
11 Throttle valve 13 Crankshaft 21 Throttle opening sensor 25 Crank angle sensor 30 ECU (electronic control unit)

Claims (5)

Throttle opening detection means for detecting the throttle opening of a throttle valve disposed in the intake passage of the internal combustion engine;
Crank angle detection means for detecting a crank angle signal accompanying rotation of the crankshaft of the internal combustion engine;
Stroke determination means for determining a stroke based on a crank angle signal detected by the crank angle detection means;
A fuel injection amount calculated based on various parameters including the throttle opening within one combustion cycle of the internal combustion engine defined by the stroke determination means is determined in accordance with the crank angle signal. A fuel injection control means for supplying from a fuel injection valve disposed in
The fuel injection control is performed when a series of operations in which the throttle valve is suddenly opened from a predetermined throttle opening and then suddenly closed within a predetermined time within one combustion cycle of the internal combustion engine defined by the stroke determination means. Forcibly stopping the supply of the fuel injection amount by the means, and the intake air amount by a series of operations of the throttle valve at this time is at least (1/3) of the intake stroke period in one combustion cycle of the internal combustion engine The fuel injection control device for the internal combustion engine, further comprising: a fuel injection correction unit that cancels the forced stop of the supply of the fuel injection amount by the fuel injection control unit.   The fuel injection correction means performs rapid opening or closing when the absolute value of the throttle opening change amount in a series of operations of the throttle valve is 0.098 [° / ms (degrees per millisecond)] or more. The fuel injection control device for an internal combustion engine according to claim 1, wherein the determination is made.   2. The fuel injection control for an internal combustion engine according to claim 1, wherein the fuel injection correction unit has an execution condition when a series of operations of the throttle valve is within 100 [ms (milliseconds)]. apparatus.   2. The internal combustion engine according to claim 1, wherein the fuel injection correction unit has an execution condition when the throttle valve is suddenly closed in a series of operations of the throttle valve and is in a closed state from a predetermined throttle opening. 3. Fuel injection control device.   5. The fuel injection control device for an internal combustion engine according to claim 1, wherein the internal combustion engine is a four-cycle single cylinder or a four-cycle multiple cylinder of independent intake.

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