JP2007303323A - Ignition timing control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition timing control device capable of surely inhibiting body fore-and-aft vibration which is unpleasant for a driver and controlling engine output not to deteriorate normal acceleration performance. <P>SOLUTION: When acceleration demand is detected during vehicle travel, change quantity DNE of engine rotation speed NE is calculated (S12 to S16) and bandpass filter treatment of the change quantity is performed (S17). When change quantity DNEF after bandpass filter treatment exceeds predetermined criterion DNEFX, retarding correction of ignition timing is performed (S18, S19). Characteristics of the bandpass filter treatment are set to extract frequency component near frequency of body fore-and-aft vibration. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ignition timing control device for an internal combustion engine, and more particularly to a device that corrects an ignition timing retardation during acceleration of the engine.

  In a vehicle driven by an internal combustion engine, if a sudden acceleration is performed while the vehicle is running, the rotation of the drive wheel cannot follow the sudden increase in the output torque of the engine, so the drive system that transmits torque from the engine to the drive wheel In particular, the drive shaft may be twisted, and the longitudinal vibration of the vehicle body may occur due to the twist of the drive shaft. Patent Document 1 discloses an ignition timing control device that suppresses vehicle body longitudinal vibration during such rapid acceleration.

According to this apparatus, the engine speed detected at the time of acceleration is subjected to a low-pass filter process, and the ignition timing is retarded when the fluctuation range of the engine speed after the low-pass filter process exceeds a predetermined threshold.
Japanese Patent No. 2731926

  However, in the apparatus disclosed in Patent Document 1, the fluctuation range of the engine speed after the low-pass filter process is obtained even when relatively rapid acceleration is performed and the vehicle body longitudinal vibration is not so rapid. Exceeds the predetermined threshold value, the ignition timing is retarded, and the acceleration performance of the engine may be impaired.

  The present invention has been made paying attention to this point, and is an ignition timing control that can reliably suppress uncomfortable vehicle longitudinal vibration and control engine output so as not to impair normal acceleration performance. An object is to provide an apparatus.

  In order to achieve the above object, an invention according to claim 1 is directed to an ignition timing control device for an internal combustion engine comprising delay angle correction means for delaying the ignition timing (IGLOG) during acceleration of the internal combustion engine (1). An acceleration request detecting means for detecting an acceleration request for the engine, a rotation speed parameter detecting means for detecting the engine speed (NE) or a change speed (DNE) of the engine speed as a speed parameter, and the detected speed Filter means for subjecting the parameters (NE, DNE) to band-pass filter processing, and the retard correction means detects the acceleration request and the rotation speed parameters (NEF, DNEF) after the band-pass filter processing by the filter means. ) Exceeds a predetermined threshold (NEFX, DNEFX), the retardation correction is executed.

  According to a second aspect of the present invention, in the ignition timing control device for an internal combustion engine according to the first aspect, the filter means generates a frequency of longitudinal vibration of a vehicle body on which the engine is mounted, which is generated when the engine is suddenly accelerated ( 3 to 5 Hz) band-pass filter processing for passing frequency components in the vicinity is performed.

  According to the first aspect of the present invention, when the detected rotation speed parameter is subjected to the bandpass filter process, the driver's acceleration request is detected, and the rotation speed parameter after the bandpass filter process exceeds a predetermined threshold value. In addition, the ignition timing retardation is corrected. Therefore, by appropriately setting the passband of the bandpass filter processing, it is possible to reliably detect sudden acceleration that causes vehicle body longitudinal vibration and effectively suppress unpleasant vibrations by correcting the retard of the ignition timing. Can do.

  According to the second aspect of the present invention, since the bandpass filter process for passing the frequency component in the vicinity of the frequency of the longitudinal vibration of the vehicle body, which occurs during the rapid acceleration of the engine, is performed, the sudden vibration that causes the longitudinal vibration of the vehicle body is generated. Acceleration can be reliably detected, and unpleasant vibration can be effectively suppressed by correcting the ignition timing retardation.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an internal combustion engine and a control device thereof according to an embodiment of the present invention. An internal combustion engine (hereinafter simply referred to as “engine”) 1 has, for example, four cylinders and includes an intake pipe 2. A throttle valve 3 is provided in the intake pipe 2.
The fuel injection valve 4 is provided for each cylinder between the engine 1 and the throttle valve 3 and slightly upstream of the intake valve (not shown) of the intake pipe 2, and each injection valve is connected to a fuel pump (not shown). At the same time, it is electrically connected to an electronic control unit (hereinafter referred to as “ECU”) 5, and the valve opening time of the fuel injection valve 4 is controlled by a control signal from the ECU 5.

A spark plug 7 is provided in each cylinder of the engine 1. The spark plug 7 is connected to the ECU 5, and ignition timing control is performed by the ECU 5.
The throttle valve 3 is provided with a throttle valve opening sensor 11 for detecting the opening TH. An intake pressure sensor 12 for detecting the pressure (intake pressure) PBA in the intake pipe 2 is provided immediately downstream of the throttle valve 3, and detection signals from these sensors are supplied to the ECU 5.

  The ECU 5 is connected to a crank angle position sensor 13 that detects a rotation angle of a crankshaft (not shown) of the engine 1, and a signal corresponding to the rotation angle of the crankshaft is supplied to the ECU 5. The crank angle position sensor 13 is a cylinder discrimination sensor that outputs a pulse (hereinafter referred to as “CYL pulse”) at a predetermined crank angle position of a specific cylinder of the engine 1, and relates to a top dead center (TDC) at the start of the intake stroke of each cylinder. A TDC sensor that outputs a TDC pulse at a crank angle position before a predetermined crank angle (every 180 degrees of crank angle in a four-cylinder engine) and one pulse (hereinafter referred to as “CRK”) with a constant crank angle cycle shorter than the TDC pulse (for example, a cycle of 6 °). The CYL pulse, the TDC pulse, and the CRK pulse are supplied to the ECU 5. These pulses are used for various timing controls such as fuel injection timing and ignition timing, and detection of engine speed (engine speed) NE.

  The ECU 5 shapes input signal waveforms from various sensors, corrects the voltage level to a predetermined level, converts an analog signal value into a digital signal value, etc., and a central processing unit (hereinafter referred to as “CPU”). A storage circuit for storing various calculation programs executed by the CPU and calculation results, an output circuit for supplying a control signal to the spark plug 7, the fuel injection valve 4, and the like.

  FIG. 2 is a diagram showing a frequency component (power spectrum PS) of the engine speed NE when the vehicle body longitudinal vibration described above occurs when the throttle valve 3 is suddenly opened and sudden acceleration is performed. . A component (arrow A) having a frequency in the vicinity of 3 to 5 Hz is increased by the longitudinal vibration of the vehicle body. The fluctuation component due to engine acceleration is a lower frequency component (arrow B) of 1 Hz or less.

  A broken line L1 in FIG. 2 indicates the frequency characteristic of the conventional low-pass filter, and a solid line L2 indicates the frequency characteristic of the band-pass filter in the present embodiment. In the characteristic of the broken line L1, since the component related to normal acceleration indicated by the arrow B is output from the filter, the ignition timing retardation correction may be performed during normal acceleration in which vehicle body longitudinal vibration does not occur. Therefore, in the present embodiment, the band-pass filter process having the characteristic indicated by the solid line L2 is executed, and the execution timing of the ignition timing retardation correction is determined based on the engine speed NEF after the filter process.

FIG. 3 is a time chart showing changes in engine speed NE, engine speed NEF after filtering, ignition timing retardation amount, and throttle valve opening TH during sudden acceleration.
During sudden acceleration in which vehicle body longitudinal vibrations occur, the post-filter engine speed NEF exceeds the threshold value, and ignition timing retardation correction is intermittently executed. On the other hand, during normal acceleration, when conventional low-pass filter processing is used, there is a possibility that retardation correction may be performed as shown by the broken line, but in this embodiment, low-frequency components are removed by band-pass filter processing. Therefore, the retardation correction is not performed.

  Note that the frequency component of the change amount DNE (= NE (k) −NE (k−1), k is a discrete sampling time) indicating the change speed of the engine speed NE is the engine speed NE shown in FIG. Therefore, in the ignition timing control described later, the execution timing of the retardation correction is determined according to the change amount DNE of the engine speed NE.

FIG. 4 is a flowchart of a process for performing the ignition timing control of the engine 1. This process is executed by the CPU of the ECU 5 in synchronization with the generation of the TDC pulse.
In step S11, the basic ignition timing IGBASE is calculated according to the detected engine speed NE and intake pressure PBA. The ignition timing is defined by the advance amount from the compression top dead center.

In step S12, it is determined whether or not the vehicle speed VP is higher than a predetermined vehicle speed VPX (for example, 3 km / h). If the answer is affirmative (YES), it is determined whether or not the throttle valve opening TH is larger than a predetermined opening THX (for example, 5 degrees) (step S13). If the answer is affirmative (YES), a throttle valve opening change amount DTH is calculated by the following equation (1) (step S14), and the throttle valve opening change amount DTH is calculated as a predetermined throttle valve opening change amount DTHX ( For example, it is determined whether it is larger than 0.5 degrees / TDC) (step S15). K in the equation (1) is a sampling time discretized in the execution cycle of this process.
DTH = TH (k) -TH (k-1) (1)

  If the answer to step S12, S13, or S15 is negative (NO), the ignition timing IGLOG is set to the basic ignition timing IGBASE calculated in step S11 (step S20), and this process ends.

If the answer to step S15 is affirmative (YES) and the vehicle is traveling rapidly, the engine speed change amount DNE is calculated by the following equation (2) (step S16).
DNE = NE (k) -NE (k-1) (2)

In step S17, a band-pass filter process for the engine speed change amount DNE is executed. Specifically, the post-filtering change amount DNEF is calculated by the calculation according to the following equation (3).
DNEF = B1 * DNE (k) + B2 * DNE (k-1) + B3 * DNE (k-2)
-A1 x DNEF (k-1)-A2 x DNEF (k-2) (3)
Here, the filter coefficients B1 to B3, A1, and A2, for example, are set as follows.
B1 = 0.01852, B2 = 0, B3 =-0.01852
A1 = -1.90122, A2 = 0.96295

  As shown in FIG. 5, the frequency characteristic of the bandpass filter processing performed by the expression (3) is a characteristic that emphasizes the frequency component (component centered at 3 to 4 Hz) in the vicinity of the frequency of the vehicle body longitudinal vibration. Is set.

  In step S18, it is determined whether or not the post-filtering change amount DNEF is greater than a predetermined threshold value DNEFX. This determination is performed so that a hysteresis characteristic is obtained. That is, when the retardation correction is not performed, the retardation correction is started when the post-filtering change amount DNEF exceeds the upper threshold value DNEFFXH (for example, 6 rpm). When DNEF falls below the lower threshold value DNEFXL (for example, 4 rpm), the retardation correction is terminated.

If the answer to step S18 is negative (NO), the process proceeds to step S20. When DNEF> DNEFX in step S18, the ignition timing IGLOG is calculated by correcting the basic ignition timing IGBASE by the following equation (4) (step S19).
IGLOG = IGBASE-IGACCR (4)
Here, IGACCR is a predetermined retardation amount for preventing vehicle body vibration.

  An ignition signal is generated according to the ignition timing IGLOG calculated by this processing, and the generated ignition signal is supplied to the spark plug 7.

  FIG. 6 is a time chart showing an operation example of the retardation correction (application of the predetermined retardation correction amount IGACCR) by the processing shown in FIG. 4, and FIGS. 6A to 6E show the post-filtering change amount DNEF. , The delay correction amount, the throttle valve opening TH, the acceleration GACC of the vehicle, and the engine speed NE. As shown by an ellipse in FIG. 4D, the retardation correction is executed at the timing when the acceleration GACC rises, and the longitudinal vibration of the vehicle body can be effectively suppressed.

  As described above in detail, in the present embodiment, the band pass filter process of the change amount DNE of the engine speed NE is performed, and when the change amount DNEF after the band pass filter process exceeds the predetermined threshold value DNEFX, the ignition timing is delayed. Since the angle correction is performed, it is possible to reliably detect the sudden acceleration that causes the vehicle body longitudinal vibration, and to effectively suppress the unpleasant vibration by correcting the retard of the ignition timing. That is, it is possible to prevent the acceleration performance from being impaired by correcting the retard of the ignition timing during normal acceleration as in the prior art.

  In this embodiment, the throttle valve opening sensor 11 corresponds to acceleration request detection means, the crank angle position sensor 13 corresponds to rotation speed parameter detection means, and the ECU 5 includes part of the rotation speed parameter detection means, filter means, and delay time. The angle correction means is configured.

  The present invention is not limited to the embodiment described above, and various modifications can be made. For example, in the embodiment described above, bandpass filter processing of the engine speed change amount DNE is performed to calculate the post-filtering change amount DNEF, and when the post-filtering change amount DNEF exceeds a predetermined threshold value DNEFX, the ignition timing is changed. Although the retard angle correction is performed, the band speed filter process is performed on the engine speed NE itself, and when the engine speed NEF after the band pass filter process exceeds the predetermined threshold value NEFX, the retard correction of the ignition timing is performed. May be performed.

  Although the acceleration request to the engine is detected by the throttle valve opening TH, an acceleration sensor for detecting the accelerator pedal depression amount AP of the vehicle may be provided, and the acceleration request may be detected by the accelerator pedal depression amount AP. In that case, the accelerator sensor corresponds to the acceleration request detecting means.

It is a figure which shows the structure of the internal combustion engine and its control apparatus concerning one Embodiment of this invention. It is a figure for demonstrating the characteristic of this invention in contrast with a prior art. It is a time chart for demonstrating the characteristic of this invention in contrast with a prior art. It is a flowchart of an ignition timing control process. It is a figure which shows the frequency characteristic of a band pass filter process. It is a time chart which shows the operation example of the control processing shown in FIG.

Explanation of symbols

1 Internal combustion engine 5 Electronic control unit (retard angle correction means, filter means, rotation speed parameter detection means)
7 Spark plug 11 Throttle valve opening sensor (acceleration request detection means)
13 Crank angle position sensor (rotational speed parameter detection means)
14 Vehicle speed sensor

Claims (2)

In an ignition timing control device for an internal combustion engine comprising a retard correction means for retarding the ignition timing during acceleration of the internal combustion engine,
Acceleration request detecting means for detecting an acceleration request for the engine;
A rotational speed parameter detecting means for detecting the rotational speed of the engine or a change speed of the engine rotational speed as a rotational speed parameter;
Filter means for performing band-pass filtering on the detected rotation speed parameter,
The internal combustion engine characterized in that the retard correction means executes the retard correction when the acceleration request is detected and a rotation speed parameter after the bandpass filter processing by the filter means exceeds a predetermined threshold value. Engine ignition timing control device.   2. The internal combustion engine according to claim 1, wherein the filter unit performs a band-pass filter process that allows a frequency component in the vicinity of a longitudinal vibration frequency of a vehicle body on which the engine is mounted to be generated when the engine is suddenly accelerated. Engine ignition timing control device.

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