JP4420349B2 - Rotational position detection device for internal combustion engine - Google Patents

Description

  The present invention relates to a rotational position detection device for an internal combustion engine, and more particularly to a rotational position detection device for an internal combustion engine that can accurately determine the rotational position of the internal combustion engine and reduce the time until the internal combustion engine starts. .

  2. Description of the Related Art Conventionally, in a four-cycle engine employing an electronic fuel injection device, a configuration is known in which stroke determination of the engine is performed by detecting a rotational position based on both a camshaft phase and a crankshaft phase.

In Patent Document 1, a first rotating body that rotates in synchronization with a camshaft and is provided with a plurality of teeth at equal intervals, and a plurality of vanes that rotate in synchronization with a crankshaft and are provided at unequal intervals are provided. A number of teeth of the first rotating body passing within a period in which both edges of the vanes of the second rotating body pass, and this is stored in the memory. An engine crankshaft angular position display conversion device that detects a rotational position of a crankshaft by collating with a collation pattern is disclosed. According to this device, accurate rotational position detection processing can be performed even under circumstances where the crankshaft rotation speed is unstable, such as during cold start, where fluctuations occur in the width between pulses. .
Japanese Examined Patent Publication No. 4-61183

  As an ignition system for an internal combustion engine, a full transistor system is known in which a primary current of an ignition coil is interrupted by amplifying signals of a rotor and a pickup coil incorporated in a distributor by a transistor amplification circuit. This ignition system is characterized in that it has a long continuous spark time and excellent ignition performance, and also requires some time from the start of energization to the ignition coil until the ignition plug is ignited. In the apparatus of Patent Document 1, no consideration is given to the time from energization to ignition, and when applied to a full-transistor internal combustion engine, the crankshaft is significantly faster than the conventional system by comparing the number pattern. Even when the rotational position of the spark plug is determined, ignition of the spark plug may not be in time for the first ignition timing immediately after that. For this reason, the actual ignition is performed at the next ignition timing, and as a result, there is a problem that the time until the internal combustion engine is started may not be shortened so much.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotational position detection device for an internal combustion engine that solves the above-described problems of the prior art, can accurately determine the rotational position of the internal combustion engine, and can shorten the time until the internal combustion engine starts. It is to provide.

  In order to achieve the above-described object, the present invention generates a pulse signal by detecting convex portions or concave portions provided at equal intervals on the peripheral portion of the first rotating body that rotates in synchronization with the rotation of the crankshaft. A rectangular wave corresponding to the shape of the first signal generating means that outputs and the convex or concave portions provided at unequal lengths in the peripheral portion of the second rotating body that rotates in synchronization with the rotation of the camshaft. Second signal generating means for generating / outputting a signal, and pattern detecting means for detecting the number of first signals corresponding to successive edges of the second signal as a pattern in association with the first signal and the second signal. And a pattern matching means for matching the pattern of the first signal with a memory pattern stored in advance and associated with the rotational position of the crankshaft, and the pattern matching means matches the pattern of the first signal. Said memory Rotation position detecting means for determining the rotation position of the crankshaft based on the turn, and timing for detecting the next edge between the edges in which the pattern is verified by energizing the ignition coil connected to the ignition plug An ignition coil energizing means for igniting the ignition plug at an interval between the convex portions formed on the second rotating body or the interval between adjacent edges of the concave portions after the ignition coil energizing means starts energizing the ignition coil. The first feature is that the rotation angle is set to be larger than the rotation angle of the crankshaft corresponding to the time until ignition of the engine.

  Further, the number of convex portions or concave portions corresponding to the number of cylinders is formed in the second rotating body, and the ignition timing of the spark plug matches the rising edge or falling edge of the convex portion of the second signal. The second feature is that the rising edge or the falling edge of the convex portion of the second signal is made to correspond to the compression top dead center of each cylinder.

  Further, the arrangement of the projections or recesses of the first rotator corresponding to a part or all of the edge portions of the projections or recesses of the second rotator is the projections of the first rotator corresponding to the other parts. Alternatively, the third feature is that the arrangement is different from the arrangement of the recesses.

  Further, the different arrangement is such that the interval between the convex portions or the concave portions of the first rotating body corresponding to part or all of the edge portion is larger than the interval between the convex portions or the concave portions of the first rotating body corresponding to the other portions. There is a fourth feature in that the arrangement is made.

  According to the first aspect of the present invention, the rotational position can be quickly detected by pattern matching even if the rotational angle of the crankshaft at the start of cranking is any number of positions. Furthermore, since the ignition plug can be reliably ignited at the first ignition timing after the rotational position is detected, the time from the end of the rotational position detection process to the start of the internal combustion engine can be shortened.

  According to the second aspect of the present invention, it becomes easy to match the reference position of the camshaft or the like at the time of assembly or maintenance of the internal combustion engine, and it is possible to improve the assemblability and the maintainability.

  According to the invention of claim 3, since the passage of the edge portion of the second rotating body can be detected also by the pulse signal from the first rotating body, the first signal corresponding to the successive edges of the second signal is detected. It is possible to suppress erroneous detection when detecting the number of the patterns as a pattern.

  According to the invention of claim 4, in the transmission mechanism that transmits the rotation of the crankshaft to the camshaft, even when a slight rotational deviation occurs due to backlash of gear parts, etc., the erroneous detection of the pattern of the first signal is suppressed. Will be able to.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a rotational position detecting device for an internal combustion engine according to the present invention. In the present embodiment, a description will be given by taking an example of a four-cycle five-cylinder engine in which one cycle of the internal combustion engine, that is, the camshaft rotates once while the crankshaft rotates twice.

  A crankshaft 1s as a crankshaft is provided with a crank pulser rotor 1 and a crank pulse generator 3 for generating a crank pulse as a first signal. Sensor teeth 1a are provided at equal intervals of 15 ° on the outer peripheral portion of the crank pulsar rotor 1 that rotates in the direction of arrow a in the figure. The crank pulse generator 3 uses an electromagnetic pickup 3 that can detect the passage of the sensor tooth 1a, and the passage state of the sensor tooth 1a accompanying the rotation of the crankshaft 1s is output as a crank pulse having a short pulse width. The

  A cam shaft 2s as a cam shaft is provided with a cam pulser rotor 2 and a cam pulse generator 4 for generating a cam pulse as a second signal. On the outer peripheral portion of the cam pulsar rotor 2 rotating in the direction of the arrow b in the figure, there are provided substantially fan-shaped sensor teeth 2a to 2e having different outer peripheral lengths and corresponding to the number of cylinders. The cam pulse generator 4 uses a Hall element capable of discriminating the strength of the magnetic field and the magnetic pole, and the passing state of the sensor teeth 2a to 2e accompanying the rotation of the camshaft 2s is a rectangular wave shape corresponding to the convex shape. Output as a cam pulse.

  The ECU (engine control unit) 10 includes a crank pulse detector 11 that detects a signal from the crank pulse generator 3 and a signal from the cam pulse generator 4 that is an L (low) level signal and an H (high) level signal. And a pulse pattern detection unit as a pattern detection unit that detects the number of passages of the crank pulse as a pulse pattern while the convex portion of the cam pulse waveform passes, that is, while the H level signal is detected. 13, a pattern for collating a pulse pattern storage unit 14 in which a storage pattern for verification is stored, and a pulse pattern detected by the pulse pattern detection unit 13 and a storage pattern stored in the pulse pattern storage unit 14 Pulse pattern verification unit 15 as a verification unit and pulse pattern verification And a rotational position detecting unit 16 as a rotational position detecting means for detecting a rotational position of the internal combustion engine based on the collation result by 15. Then, based on the processing result by the rotational position detection unit 16 and information such as the engine speed and the vehicle speed, the fuel injection device driving means 17 controls the fuel injection device 18 and the ignition coil energization means 19 is connected to the ignition plug 21. Electric power for ignition is applied to the ignition coil 20.

  Next, the rotational position detection process executed by the ECU 10 will be described with reference to the flowchart of FIG. 2 and the timing chart of FIG. When the main switch is turned on to turn on the ECU 10 to start the internal combustion engine, the “rotational position detection process” shown in the flowchart of FIG. 2 is started.

  When the flowchart of FIG. 2 is activated and a crank pulse and a cam pulse are detected in step S10, it is determined in step S11 whether or not the rotational position of the internal combustion engine is fixed. Here, since the rotational position has not yet been determined, the process proceeds to step S12.

  The timing chart of FIG. 3 shows the rotation angle of the crankshaft with reference to the first cylinder and the waveforms of the crank pulse and the cam pulse that are detected as the rotation angle varies. These waveforms are configured based on signals from the crank pulse detection unit 11 and the cam pulse detection unit 12. The number of crank pulses shown in the lower stage of the cam pulse indicates the number of crank pulses that pass during the period in which the convex portion of the cam pulse is detected (the number in parentheses indicates the number that passes in the period in which the concave portion is detected). Further, one cycle period of the engine is divided into 1 to 48 stages based on 24 sensor teeth 1a provided at equal intervals in the crank pulsar rotor 1. The number of stages shown in the lower stage of the crank pulse and the stroke classification (intake / compression / explosion / exhaust) in the first to fifth cylinders (# 1 to 5) are determined when the rotational position detection processing according to the present invention is completed. It will become clear. Further, the circles shown in the column of the crank pulse indicate locations to which the number of stages found with the completion of the rotational position detection process is applied.

  Attention is paid to the waveform of the cam pulse. The sensor teeth 2a to 2e of the cam pulse rotor 2 are respectively compression top dead centers (2a = 4th cylinder, 2b = 1st cylinder, 2c = 2th cylinder, 2d = 5th cylinder, 2e = 3rd cylinder) In the drawing, they are arranged so as to correspond to TDC). The rising edge of each sensor tooth, that is, the point at which the cam pulse waveform changes from the concave side to the convex side, coincides with the ignition timing located immediately before the compression top dead center of each cylinder (7.5 ° before this embodiment). Are arranged to be. In the drawing, this ignition timing is indicated by an asterisk in the column of steps # 1 to # 5. Further, since the internal combustion engine according to the present embodiment employs a full-transistor ignition system, the ignition coil energizing means 19 starts energizing the ignition coil 20 until the ignition plug 21 is ignited. It takes some time to complete. Thus, in order to ignite at the ignition timing indicated by each star, energization to the ignition coil must be started at the timing indicated by the downward arrow p on the left side. The interval from the start of energization to ignition is determined by the characteristics of the devices that make up the ignition system. In this embodiment, the crankshaft rotation angle for approximately two crank pulses is required. In the present embodiment, a processing procedure when cranking is started when the crankshaft rotation angle is 270 ° is shown.

  Returning to FIG. 2, in step S12, it is determined whether or not the rising edge of the cam pulse has passed. If it is determined in step S12 that the rising edge has passed, the process proceeds to step S13 to start counting the crank pulse, and in step S14, the counting is continued as it is. In the present embodiment, when the crankshaft rotation angle reaches 277.5 °, the rising edge of the sensor tooth 2a is detected (see FIG. 3), so the counting of the crank pulse is started. If it is determined in step S12 that the rising edge of the cam pulse has not passed, the process returns to step S10 to detect the crank pulse and the cam pulse again.

  In step S15, it is determined whether or not the falling edge of the cam pulse has passed. If it is determined that the cam pulse has passed, the process proceeds to step S16 to record the crank pulse count. In this embodiment, when the crankshaft rotation angle reaches 307.5 °, a falling edge that changes from the convex side to the concave side is detected (see FIG. 3), so the number of crank pulses counted so far is detected. “2” is recorded in the pulse pattern detector 13. If it is determined in step S15 that the falling edge of the cam pulse has not passed, the process returns to step S14 to continue counting the crank pulse.

  When the pulse pattern matching process is completed in the subsequent step S17, the process proceeds to step S18 to determine the rotational position of the crankshaft, and the rotational position detection process is terminated. The pulse pattern used for the collation process in step S17 is the number of crank pulses recorded in the pulse pattern detector 13, and is “2” in this embodiment. Here, reference is made to FIG. 4 showing a memory pattern for verification stored in the pulse pattern storage unit 14 (see FIG. 1).

  FIG. 4 is a list showing the memory patterns for verification, the number of next stages and the next ignition cylinder number corresponding to each memory pattern. As described above, since the pulse pattern applied in the present embodiment is “2”, it is determined by comparison with the table that the number of next stages is “22” and the next ignition cylinder number is “1”. . Since the next ignition cylinder number is a matter derived from the stroke, ignition timing, etc. of each cylinder determined based on the number of stages, it need not be stored independently in the data table as shown.

  Returning to FIG. 3, the number of the next stage described above is applied when the first crank pulse after the pulse pattern matching process is detected. Therefore, in this embodiment, the matching at the crankshaft rotation angle of 307.5 ° is performed. After the processing, the stage number of 22 is applied when the next crank pulse is detected at 315 °. Therefore, in the processing example of the above embodiment, the rotational position detection process is completed when the crankshaft 1s rotates 45 ° from the start of cranking.

  On the other hand, the ignition coil energization means 19 (see FIG. 1) is ready to energize the ignition coil 20 when the rotational position detection process is completed. Here, after completion of the rotational position detection process, in the first cylinder that reaches the ignition timing at a crankshaft rotation angle of 352.5 °, the energization preparation is completed before the energization start timing for the ignition coil. Even if the time lag due to the method exists, the ignition plug of the first cylinder can be reliably ignited. The reason for this effect is that the interval from the falling edge to the next rising edge in the cam pulse, that is, the L level period is set to be longer than the period required from the start of energization to the spark plug. . For example, if the period from the completion of the rotational position detection process to the next ignition timing is shorter than the time lag, even if the ignition timing is known, the actual ignition is not in time, and it is not necessary to wait until the next ignition timing. However, in the rotational position detecting device for an internal combustion engine according to the present invention, the intervals between the sensor teeth 2a to 2e are set so that such a situation does not occur.

  According to the configuration as described above, even if the crankshaft rotation angle at the start of cranking is in any number of positions, it corresponds to one of the five types of pulse patterns shown in FIG. Detection can be performed. In addition, since the spark plug can be reliably ignited at the first ignition timing that appears after the rotational position detection process, the time from the completion of the rotational position detection process to the start of the engine can be shortened. Furthermore, the rising edge of the cam pulse, that is, the rising edge of the sensor teeth of the cam pulse rotor, is set to correspond to the compression top dead center of each cylinder, making it easier to match the reference position during engine assembly and maintenance. As a result, assembly and maintenance can be improved. In the present embodiment, the rotation angle from the start of cranking to the first ignition is 82.5 ° in the above-described processing example, and the minimum value is 82.5 °. Even at the maximum value, the crankshaft rotation angle is 360 °. It is clear that 352.5 ° when ranking is started, and that the engine can be started in a small rotation angle, in other words, in a short time.

  Further, the number and shape of the sensor teeth of the crank pulsar rotor and cam pulsar rotor according to the present invention, the timing and range for counting the crank pulses, the pulse pattern for collation, etc. are not limited to those of the above-described embodiments, but various Needless to say, the deformation is possible. For example, an arbitrary number of missing teeth are provided in the sensor tooth row of the crank pulsar rotor 1, and a part or all of the edge portion of the cam pulse corresponds to a portion where the recess of the crank pulse becomes wider than the others. The sensor teeth of the cam pulser rotor 2 can also be formed. With this configuration, it is possible to suppress erroneous detection of the count number even in the case where a slight rotational deviation occurs due to backlash of gear parts in the transmission mechanism that transmits the rotation of the crankshaft to the camshaft. become able to.

1 is a block diagram of an embodiment of a rotational position detection device for an internal combustion engine according to the present invention. It is the flowchart which showed the procedure of rotational position detection. It is a timing chart showing a procedure of rotation position detection. The number of stages and the next ignition cylinder number corresponding to the collating pulse pattern.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Crank pulsar rotor, 1s ... Crank shaft, 1a ... Sensor tooth, 1b ... Missing tooth part, 2 ... Cam pulsar rotor, 2s ... Cam shaft, 2a-2e ... Sensor tooth, 3 ... Crank pulse generator, 4 ... Cam pulse Generator 10, ECU 11, crank pulse detector 12, cam pulse detector 13, pulse pattern detector 14, pulse pattern storage 15, pulse pattern collator 16, rotational position detector 19 Ignition coil energizing means, 20 ... ignition coil, 21 ... ignition plug

Claims (5)

A first that generates and outputs a pulse signal by detecting convex portions (1a) or concave portions provided at equal intervals on the peripheral portion of the first rotating body (1) that rotates in synchronization with the rotation of the crankshaft (1s) . Signal generating means (3) ;
By detecting convex portions (2a, 2b, 2c, 2d, 2e) or concave portions provided at unequal lengths on the peripheral portion of the second rotating body (2) rotating in synchronization with the rotation of the cam shaft (2s) Second signal generating means (4) for generating and outputting a rectangular wave signal corresponding to the shape;
Pattern detecting means (13) for associating the first signal and the second signal, and detecting the number of first signals corresponding to successive edges of the second signal as a pattern;
Pattern collating means (15) for collating the pattern of the first signal with a memory pattern stored in advance and associated with the rotational position of the crankshaft (1s) ;
A rotational position detecting means (16) for determining a rotational position of the crankshaft (1s) based on the stored pattern that matches the pattern of the first signal as a result of the collation by the pattern collating means (15) ;
Is connected to the spark plug (21) is energized the ignition coil (20), next edge ignition coil energizing means for igniting the spark plug (21) with timing detected between edges of performing collation of the pattern ( 19)
The convex portions (2a, 2b, 2c, 2d, 2e) or the concave portions formed on the second rotating body (2) are provided at unequal intervals as many as the number of cylinders of the engine,
The spark plug after the energization means (19) starts energizing the ignition coil (20) with the shortest interval among the adjacent edges of the convex portions (2a, 2b, 2c, 2d, 2e) or the concave portion. The rotational position detecting device for an internal combustion engine, characterized in that it is set larger than the rotational angle of the crankshaft (1s) corresponding to the time until ignition of (21) . The ignition timing of the spark plug (21) is set so as to coincide with the rising edge or falling edge of the convex portion (2a, 2b, 2c, 2d, 2e) of the second signal,
2. The internal combustion engine according to claim 1, wherein a rising edge or a falling edge of the convex portion (2 a, 2 b, 2 c, 2 d, 2 e) of the second signal corresponds to the compression top dead center of each cylinder. Engine rotational position detection device. The ignition timing of the spark plug (21) is set so as to coincide with the rising edges of the convex portions (2a, 2b, 2c, 2d, 2e) of the second signal,
The rotational position of the internal combustion engine according to claim 2, wherein rising edges of the convex portions (2a, 2b, 2c, 2d, 2e) of the second signal correspond to the compression top dead center of each cylinder. Detection device. The convex portion (1a) of the first rotating body (1 ) or the convex portion (1a) of the first rotating body (1) corresponding to a part or all of the convex portion (2a, 2b, 2c, 2d, 2e) or the edge portion of the concave portion of the second rotating body (2) The rotational position of the internal combustion engine according to claim 2, wherein the concave portion is arranged differently from the convex portion (1a) or the concave portion of the first rotating body (1) corresponding to the other portion. Detection device. The different arrangement is such that the interval between the convex portions (1a) or the concave portions of the first rotating body (1) corresponding to a part or all of the edge portions is different from the convex portions of the first rotating body (1) corresponding to the other portions. The rotational position detection device for an internal combustion engine according to claim 4 , wherein the arrangement is larger than the interval between the portions (1a) or the recesses.

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