JP2006233769A - Acceleration controller for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control amount of fuel injection and ignition time when accelerating by taking respective control response properties into account. <P>SOLUTION: This acceleration controller for the internal combustion engine has a basic injection amount calculating part 12, a basic ignition time calculating part 17, an injection amount compensating part 16 for compensating basic amount of fuel injection when accelerating, and an ignition time compensating part 19 for compensating basic ignition time when accelerating. An injection amount acceleration compensating value calculating part 15 determines that demand for acceleration is given when amount of fluctuation of throttle opening exceeds a threshold value and calculates an injection amount acceleration compensating value. An ignition time acceleration compensating value calculating part 18 determines that demand for acceleration is given when amount of fluctuation of rotational speed of an engine exceeds a threshold value and calculates an ignition time acceleration compensating value. The injection amount compensating part 16 compensates basic amount of fuel injection Q by an acceleration compensating value Tacc. The ignition time compensating part 19 compensates basic ignition time θIG by an ignition time acceleration compensating value KθIG. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an acceleration control device for an internal combustion engine, and more particularly to an acceleration control device for an internal combustion engine suitable for improving the acceleration feeling by adapting the fuel injection amount and the ignition timing to acceleration.

When controlling the fuel injection amount and the ignition timing according to the acceleration of an internal combustion engine mounted on the vehicle as a vehicle drive source, the engine acceleration is generally determined based on the throttle opening. Japanese Patent Application Laid-Open No. 2004-324418 discloses an ignition control device that corrects the ignition time and the ignition timing when acceleration is detected based on the rotational fluctuation of the internal combustion engine.
JP 2004-324418 A

  In general, when fuel injection control and ignition timing control are performed in accordance with changes in the operating state of the internal combustion engine, the control result is reflected, rather than the air-fuel mixture having an appropriate air-fuel ratio actually being sucked into the combustion chamber, The ignition timing changes quickly. That is, the responsiveness of the ignition control is better than the fuel injection control. Therefore, when the fuel injection control and the ignition timing control are performed based on the acceleration determination based on the throttle opening, the ignition control takes precedence.

  On the other hand, when the fuel injection control and the ignition timing control are performed based on the acceleration judgment based on the rotational fluctuation of the internal combustion engine, the ignition timing is appropriately changed, but the change in the fuel injection amount is reflected in the air-fuel ratio and the appropriate air-fuel ratio is changed. The intake of the fuel-air mixture at the fuel ratio into the combustion chamber is delayed from the time of throttle operation.

  The object of the present invention is to solve the above-mentioned problems of the prior art and improve the acceleration feeling by adapting the fuel injection control and the ignition timing control to the driver's intention to accelerate and the actual state of the internal combustion engine. An object of the present invention is to provide an acceleration control device for an internal combustion engine.

  In order to achieve the above object, the present invention uses basic injection amount calculation means for calculating a basic fuel injection amount using a plurality of parameters including the throttle opening, and a plurality of parameters including the throttle opening. Basic ignition timing calculating means for calculating the basic ignition timing, injection quantity correcting means for correcting the basic fuel injection amount when the internal combustion engine is accelerated, and ignition timing correcting means for correcting the basic ignition timing when the internal combustion engine is accelerated. In the acceleration control device for an internal combustion engine having the above, when the amount of change in the throttle opening detected every predetermined time is equal to or greater than a threshold value, it is determined that the vehicle is accelerating and the injection amount acceleration correction value is calculated When the injection amount acceleration correction value calculating means input to the injection amount correcting means and the amount of change in the rotational speed of the internal combustion engine detected every predetermined time are equal to or greater than a threshold value, it is determined that the vehicle is accelerating. do it There is a first feature in that provided an ignition timing acceleration correction value calculating means calculates the fire period acceleration correction value input to the injection amount correction means.

  Further, the present invention includes a map in which the ignition timing acceleration correction value calculation means sets an ignition timing acceleration correction value using the engine speed and the throttle opening as parameters for a predetermined engine speed change amount, The second feature is that the ignition timing acceleration correction value is obtained by searching for.

  Further, according to the present invention, the ignition timing acceleration correction value calculation means sets an ignition timing acceleration correction value using the engine speed and the throttle opening as parameters at a predetermined engine speed change amount interval at a predetermined engine speed change amount interval. If the detected rotational speed change amount does not correspond to the rotational speed change amount set in the map, it corresponds to a plurality of rotational speed change amounts adjacent to the detected rotational speed change amount. A third feature is that the ignition timing acceleration correction value is used to interpolate the ignition timing acceleration correction value corresponding to the detected rotation speed change amount.

  According to the above feature, regarding the control of the air-fuel mixture having a slow control response, the acceleration determination can be performed by the change in the throttle opening that can directly reflect the operator's intention to accelerate. On the other hand, with respect to the control of the ignition timing with quick control response, the acceleration judgment can be made based on the change in the rotational speed of the internal combustion engine that can directly reflect the rotational fluctuation of the internal combustion engine. Thus, since the fuel injection amount and the ignition timing can be corrected at the time of the accurately determined acceleration, an acceleration feeling suitable for the operator's request can be realized.

  If a three-dimensional map is set using parameters such as the amount of change in the rotational speed, the throttle opening, and the rotational speed of the internal combustion engine, the storage capacity of the map increases and a large storage device is required, which may increase the cost. However, according to the third feature, since the ignition timing acceleration correction value is stored at a predetermined rotation speed change amount interval, the storage capacity can be reduced. Further, when a corresponding rotation speed change amount is detected in the interval of the rotation speed change amount interval, an interpolation calculation using an ignition timing acceleration correction value corresponding to a predetermined rotation speed change amount before and after the rotation speed change amount can be performed. it can. Accordingly, it is possible to obtain an optimal correction value for any amount of change in the rotational speed while reducing the storage capacity.

  In addition, since the ignition timing acceleration correction value is mapped and the basic injection amount determined from various parameters is corrected by the correction value retrieved from this map, the data for determining the basic injection amount is accelerated. Storage capacity can be reduced without increasing by adding control.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 2 is a system configuration diagram of a main part of an internal combustion engine (hereinafter referred to as “engine”) including an acceleration control apparatus according to an embodiment of the present invention. An intake port 22 and an exhaust port 23 are opened in the combustion chamber 21 of the engine 20, and an intake valve 24 and an exhaust valve 25 are provided in the ports 22 and 23, respectively. A spark plug 26 is provided in the upper part of the combustion chamber 21.

  In an intake passage 27 communicating with the intake port 22, a throttle valve 28 that adjusts the intake air amount according to the opening θTH, a throttle sensor 5 that detects the opening θTH, and a negative pressure sensor 6 that detects the intake negative pressure PB. Is provided. An air cleaner 29 is provided at the end of the intake passage 27. An air filter 30 is provided in the air cleaner 29, and outside air is taken into the intake passage 27 through the air filter 30.

  In the intake passage 27, the injection valve 8 is disposed on the downstream side of the throttle valve 28, and the intake air temperature sensor 2 for detecting the intake (atmosphere) temperature TA is provided in the air cleaner 29 on the upstream side of the throttle valve 28. ing.

  A crankshaft 33 is connected to the piston 31 of the engine 20 via a connecting rod 32. On the outer periphery of the crankshaft 33, a reluctator 33A having protrusions provided at predetermined angular intervals corresponding to the rotation angle of the crankshaft 33 is attached. The crank pulser 4 is provided on the outer periphery of the reluctator 33A. The crank pulser 4 outputs a pulse signal (crank pulse) every time it detects a protrusion of the reluctator 33A. The engine speed NE can be calculated based on the crank pulse.

  Further, a vehicle speed sensor 7 that detects the vehicle speed V is disposed opposite to a rotating body 34 such as a gear that is connected to the crankshaft 33 and rotates. A water jacket 3 formed around the engine 20 is provided with a water temperature sensor 3 that detects a cooling water temperature TW representative of the engine temperature.

  The ECU (engine control device) 1 includes a fuel injection control unit 1A and an ignition timing control unit 1B. The fuel injection control unit 1A and the ignition timing control unit 1B can be realized by a microcomputer function (described later). The fuel injection control unit 1A outputs an injection signal QINJ to the injection valve 8 based on signals (process values) detected by the sensors. This injection signal QINJ is a pulse signal having a pulse width corresponding to the fuel injection amount Q ', and the injection valve 8 is opened for a time corresponding to this pulse width and injects fuel. The ignition timing control unit 1B controls the ignition timing of the ignition plug 26.

  FIG. 1 is a block diagram showing the main functions of the ECU 1, and the same reference numerals as those in FIG. 2 represent the same or equivalent parts. The first acceleration determination unit 10 outputs an acceleration detection signal Dacc1 when the change amount ΔθTH of the throttle opening θTH per predetermined time (for example, a predetermined interruption cycle, crank pulse generation cycle, etc.) is larger than a threshold value ΔθTHref. To do. The second acceleration determination unit 11 outputs an acceleration detection signal Dacc2 when the amount of change ΔNE of the engine speed NE per predetermined time (for example, a predetermined interruption cycle, crank pulse generation cycle, etc.) is larger than a threshold value ΔNEref. To do.

  The basic injection amount calculation unit 12 calculates a basic fuel injection amount Q of the fuel injection valve 8 by searching a map based on the engine speed NE, the throttle opening θTH, and the intake pressure PB. The correction coefficient calculation unit 13 calculates an intake negative pressure correction coefficient Kpb, an intake air temperature correction coefficient Kta, a cooling water temperature correction coefficient Ktw, and the like based on process values such as the intake negative pressure PB, the intake air temperature TA, and the cooling water temperature TW. To do. The adder 14 adds all these correction coefficients to calculate a total correction coefficient Ktotal. When the acceleration detection signal Dacc1 is input, the acceleration correction value calculation unit 15 calculates an acceleration increase value Tacc for increasing the basic fuel injection amount Q. The acceleration increase value Tacc is calculated as a function of, for example, the throttle opening θTH, the intake negative pressure PB, and the engine speed NE.

  The injection amount correction unit 16 corrects the basic fuel injection amount Q by the equation (f1) using the total correction coefficient Ktotal, the acceleration increase value Tacc, and the invalid injection time TiVB, and determines the fuel injection amount Q ′. Q '= Q * Ktotal + Tacc + TiVB (f1). In the equation (f1), the invalid injection time TiVB is a time during which the fuel is not completely injected out of the valve opening time of the injection valve 8, and is determined by the type and structure of the injection valve 8. An injection signal QINJ representative of the determined fuel injection amount Q ′ is input to the injection valve 8.

  The basic ignition timing calculation unit 17 calculates the basic ignition timing θIG by map search using the engine speed NE and the throttle opening θTH as parameters. The basic ignition timing θIG is an advance amount from the compression top dead center. When the acceleration detection value Dacc2 is input, the acceleration correction value calculation unit 18 searches the acceleration correction ignition timing map and calculates the acceleration correction amount KθIG. The acceleration correction ignition timing map is an advance angle amount that is set in advance for each or a plurality of rotation speed change amounts ΔNE with the acceleration correction amount KθIG as a parameter of the engine rotation speed NE and the throttle opening θTH.

  The ignition timing correction unit 19 corrects the basic ignition timing θIG by the equation (f2) using the acceleration correction amount KθIG to determine the ignition timing θ′IG. θ′IG = θIG + KθIG (f2). The ignition circuit 26A of the ignition plug 26 performs ignition by triggering the ignition plug 26 according to the determined ignition timing θ′IG.

  FIG. 3 is a flowchart of basic fuel injection amount calculation in the fuel injection control unit 10. In step S1 of FIG. 3, the engine speed NE is calculated and read based on the crank pulse (for example, based on the cycle of the crank pulse). In step S2, the throttle opening θTH is read. In step S3, the change amount ΔθTH of the throttle opening θTH, that is, the difference between the previous value and the current value of the throttle opening θTH detected in step S2 is calculated. In step S4, the intake negative pressure PB is read. In step S5, the change amount ΔθTH of the throttle opening θTH is compared with the reference change amount ΔθTHref.

  If the change amount ΔθTH is less than the reference change amount ΔθTHref, it is determined that the throttle operation is slow and the engine 20 is operating in a steady state, and in this case, the process proceeds to step S7. In step S7, a PB map used by the basic injection amount calculation unit 12 is selected. The PB map is obtained by previously registering an injection time Q as an injection time set with the engine speed NE and the intake negative pressure PB as parameters.

  If it is determined in step S5 that the change amount ΔθTH is equal to or greater than the reference change amount ΔθTHref and the engine 20 is in an acceleration state, the process proceeds from step S5 to step S6. In step S6, a TH map used by the basic injection amount calculation unit 12 is selected. The TH map is obtained by previously registering an injection time Q set using the engine speed NE and the throttle opening θTH as parameters.

  In step S8, using the map selected in step S6 or step S7, a PB map is searched based on the engine speed NE and the intake negative pressure PB, or based on the engine speed NE and the throttle opening θTH. The TH map is searched to calculate the basic injection time Q.

  FIG. 7 is a flowchart of correction including acceleration increase in the fuel injection control unit 10. In step S10, it is determined whether or not an engine acceleration operation has been performed based on whether or not the throttle opening θTH has increased. When the acceleration operation is performed, the process proceeds to step S11, and the acceleration increase value Tacc is calculated based on the throttle opening change amount ΔθTH, the intake negative pressure PB, and the engine speed NE. Note that when the engine 20 is connected to a load via a speed reducer, the speed reduction ratio can also be taken into account in the calculation of the acceleration increase value Tacc. In step S12, the total correction coefficient Ktotal, the acceleration increase value Tacc, and the invalid injection time TiVB are calculated using the equation (f1) to the basic fuel injection amount Q to determine the correction fuel injection amount Q '. In step S13, a pulse signal having a pulse width corresponding to the corrected fuel injection time Q ′ calculated in step S12, that is, a drive signal is supplied to the injection valve 8. The injection valve 8 opens the injection time Q ′ and injects fuel.

  When the acceleration operation is not detected in step S10, the process proceeds to step S14, and it is determined whether or not the injection that has been subjected to the acceleration increase correction is executed in the previous process of this flowchart. When the previous acceleration increase correction is executed, the process proceeds to step S15 to attenuate the acceleration increase value Tacc. For example, a preset value is subtracted from the current acceleration increase value Tacc, or the acceleration increase value Tacc is set to zero. The process proceeds from step S15 to step S12.

  If the previous acceleration increase correction has not been executed, step S15 is skipped and the process proceeds from step S10 to step S12.

  Next, the operation of the ignition timing control unit 11 will be described with reference to the flowchart of FIG. In FIG. 4, the ignition timing θ′IG is calculated. In step S20, the engine speed NE is calculated and read. In step S21, the throttle opening degree θTH is read. In step S22, the ignition timing θIG is calculated based on the throttle opening θTH and the engine speed NE. A map using the throttle opening θTH and the engine speed NE as parameters is set in advance, and the basic ignition timing θIG can be obtained using this map.

  In step S23, a change amount ΔNE of the engine speed NE is detected. The change amount ΔNE is a change amount (NE2−NE1) from the engine speed NE1 at the previous ignition timing calculation to the engine speed NE2 at the current calculation. In step S24, it is determined whether or not the change amount ΔNE is greater than or equal to the acceleration determination threshold value ΔNEref. If step S24 is negative, the engine 20 is in a steady operation state, and the process proceeds to step S25 to set “0” as the acceleration correction amount KθIG.

  If step S24 is positive, the engine 20 is determined to be in an accelerated state, and the process proceeds to step S26. In step S26, the ignition acceleration correction map is searched based on the engine speed Ne and the throttle opening degree θTH, and the acceleration correction amount KθIG is read out. An example of the ignition acceleration correction map is shown in FIG. In the ignition acceleration correction map, an acceleration correction amount KθIG is registered in advance with the engine speed NE (NE1 to NEn) and the throttle opening θTH (TH1 to THn) as parameters. FIG. 5 shows the acceleration correction amount KθIG when the change amount ΔNE of the engine speed NE is 500 rpm. Accordingly, in step S27, an interpolation calculation is performed based on the acceleration correction amount KθIG read in step S23 to determine the acceleration correction amount KθIG.

  In step S28, the basic ignition timing θIG is corrected by the equation (f2) using the calculated acceleration correction amount KθIG, and the ignition timing θ′TH is calculated.

  FIG. 6 is a schematic diagram of the interpolation calculation of the acceleration correction amount KθIG. In FIG. 6, the acceleration correction amount KθIG corresponding to the lower limit engine speed change amount ΔNELLMT (0 rpm) for executing the acceleration correction is set to zero, and the acceleration correction amount KθIG at the change amount ΔNE 500 rpm is set to the engine speed NE and the throttle opening. If the current detection change amount ΔNE is 200 rpm when the degree θTH is read as 15 ° on the map of FIG. 5, the acceleration correction amount KθIG of ΔNE at 200 rpm is calculated as 6 ° by the equation (f3). KθIG = 200/500 × 15 (f3).

  When a single map is prepared for the reference engine speed change amount ΔNE (for example, 500 rpm), interpolation is performed as described with reference to FIG. 6. For example, for a plurality of engine speed change amounts ΔNE, When a map is prepared, interpolation calculation is performed using two maps close to the detected change amount ΔNE.

It is a principal part functional block diagram of the acceleration control apparatus which concerns on one Embodiment of this invention. 1 is a system configuration diagram of an engine including an acceleration control device according to an embodiment of the present invention. It is the flowchart which showed the control procedure of fuel injection. It is a flowchart of ignition control. It is the figure which showed an example of the acceleration correction amount map. It is a schematic diagram which shows the interpolation method of the acceleration correction amount. 5 is a flowchart of fuel injection control including acceleration increase.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... ECU, 4 ... Crank pulser, 5 ... Throttle opening degree ((theta) TH) sensor, 6 ... Intake pressure (PB) sensor, 8 ... Fuel injection valve, 10 ... 1st acceleration judgment part, 11 ... 2nd acceleration judgment part, DESCRIPTION OF SYMBOLS 12 ... Basic injection amount calculation part 15, 18 ... Acceleration correction value calculation part, 20 ... Engine, 26 ... Spark plug, 28 ... Throttle valve, 33 ... Crankshaft

Claims (3)

A basic injection amount calculating means for calculating a basic fuel injection amount using a plurality of parameters including the throttle opening; a basic ignition timing calculating means for calculating a basic ignition timing using a plurality of parameters including the throttle opening; An internal combustion engine acceleration control apparatus comprising: an injection amount correction unit that corrects the basic fuel injection amount during acceleration of the internal combustion engine; and an ignition timing correction unit that corrects the basic ignition timing during acceleration of the internal combustion engine.
An injection amount acceleration correction value calculating means for calculating an injection amount acceleration correction value and inputting it to the injection amount correction means when the change amount of the throttle opening detected every predetermined time is equal to or greater than a threshold value;
An ignition timing acceleration correction value calculating means for calculating an ignition timing acceleration correction value and inputting it to the injection amount correction means when the amount of change in the rotational speed of the internal combustion engine detected at a predetermined time is equal to or greater than a threshold value; An acceleration control apparatus for an internal combustion engine, comprising:   The ignition timing acceleration correction value calculation means includes a map in which an ignition timing acceleration correction value using parameters of the engine speed and the throttle opening of the internal combustion engine at a predetermined engine speed change amount is set as a parameter. 2. The acceleration control device for an internal combustion engine according to claim 1, wherein the acceleration control value is obtained. The ignition timing acceleration correction value calculation means includes a map in which ignition timing acceleration correction values using the engine speed and the throttle opening as parameters are set at predetermined speed change intervals at predetermined speed change intervals. ,
When the detected rotational speed change amount does not correspond to the rotational speed change amount set in the map, the ignition timing acceleration correction value corresponding to a plurality of rotational speed change amounts adjacent to the detected rotational speed change amount is used. 2. The acceleration control device for an internal combustion engine according to claim 1, wherein the ignition timing acceleration correction value corresponding to the detected rotational speed change amount is interpolated.

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