JP4521661B2 - Cylinder discrimination device for internal combustion engine - Google Patents

Description

  The present invention relates to a cylinder discriminating device for an internal combustion engine, and more particularly to a cylinder discriminating device for an internal combustion engine that shortens the time required for cylinder discrimination.

  An internal combustion engine mounted on a vehicle or the like generally includes a plurality of cylinders, and it is necessary to determine which cylinder is in order to control the ignition timing, fuel injection timing, and the like of each cylinder. As a cylinder discriminating apparatus for discriminating a cylinder of an internal combustion engine having a plurality of cylinders as described above, there are those already disclosed.

JP-A-8-277744 JP 2002-276454 A Japanese Patent Laid-Open No. 2003-3901 JP 2003-172194 A JP 2004-44470 A

  Incidentally, in a conventional cylinder discrimination device for an internal combustion engine, as disclosed in Japanese Patent Publication No. 6-68252 and Japanese Patent Laid-Open No. 5-106500, a crank angle sensor for detecting rotation of a crankshaft and a camshaft Cylinder discrimination is performed by a combination of two systems of signals with a cam angle sensor that detects rotation, but the case where the cam is advanced by a variable valve timing mechanism (also referred to as “VVT mechanism”) is clearly stated. In addition, when the phase of the cam angle signal is shifted, there is a disadvantage that some of the cam angle signals are out of the cylinder discrimination condition and cannot be discriminated.

  Further, as disclosed in Japanese Patent No. 2595848 and Japanese Patent Application Laid-Open No. 2002-97990, when an abnormality occurs in one of the two systems of signals, cylinder discrimination is performed based on the remaining one system of signals. A device having a fail-safe function has also been proposed, but there is a problem in that it does not take into account the correspondence to the above-described VVT mechanism.

Therefore, the present invention eliminates the above-mentioned inconveniences.
In a cylinder discrimination device for an internal combustion engine comprising a camshaft having a first signal member, a cam angle sensor, a crankshaft having a second signal member, a crank angle sensor, and a variable valve timing mechanism,
The first signal member includes a cam angle signal generation unit that generates a plurality of cam angle signals that can be detected by the cam angle sensor and includes at least a cylinder discrimination signal;
The second signal member is a crank that can be detected by the crank angle sensor and that generates an angle signal for each first predetermined angle except for a plurality of predetermined angle ranges in synchronization with rotation of the crankshaft. An angular signal generator and a missing tooth portion that does not generate an angle signal over a first predetermined angle;
This missing tooth portion is composed of a first missing tooth portion and a second missing tooth portion, and the number of angle signals generated along the rotation direction of the crank angle is from the first missing tooth portion to the second missing tooth portion. And the number detected from the second missing tooth part to the first missing tooth part are different from each other,
A cylinder discriminating means for discriminating a cylinder from the number of angle signals generated between the toothless portions of the second signal member and the number of cam angle signals ;
In a state where the variable valve timing mechanism is operating, from the number of angle signals generated between the tooth missing portions of the second signal member and the cam angle signal value immediately before counting the angle signals between the tooth missing portions. It is characterized by discriminating cylinders .

  As described above in detail, according to the present invention, the cylinder can be discriminated from the number of crank angle signals generated between the tooth missing portions and the number of cam angle signals, and the time required for cylinder judgment can be shortened. Is possible.

  As a result of the invention as described above, the cylinder discriminating means discriminates the cylinder based on the number of crank angle signals and cam angle signals generated between the tooth missing portions, thereby shortening the time required for cylinder discrimination.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  1 to 15 show an embodiment of the present invention. In FIG. 1, 2 is a cylinder discrimination device for an internal combustion engine.

  An internal combustion engine (not shown) has a plurality of cylinders, in this embodiment, three cylinders of a first cylinder # 1 to a third cylinder # 3, and an intake system and an exhaust system are provided.

  The internal combustion engine pivotally supports a crankshaft (not shown) on a cylinder block (not shown), and an intake camshaft (not shown) and an exhaust camshaft (not shown) on the cylinder head. A crank pulley (not shown) is provided on one end of the shaft, and an intake cam pulley (not shown) and an exhaust cam pulley (not shown) are provided on one end of each of the intake cam shaft and the exhaust cam shaft. The intake camshaft and the exhaust camshaft are rotated in synchronism with the rotation of the crankshaft by a timing chain, a timing belt (not shown) or the like that is strung over the cam pulley and the exhaust cam pulley.

  The cylinder discrimination device 2 of the internal combustion engine is provided with a first signal member (not shown) using an intake cam pulley on one end side of the intake camshaft, and a cam angle sensor that detects a cam signal from the first signal member. Is provided. This cam angle sensor is used in combination with a variable valve timing mechanism (also referred to as “VVT mechanism”) (not shown) that varies the valve timing of an intake / exhaust valve (not shown).

  The advance angle control of the variable valve timing mechanism (also referred to as “VVT mechanism”) can be used in the same manner as the conventional one.

  The cylinder discriminating device 2 is provided with a second signal member (not shown) using a crank pulley on one end side of the crankshaft, and a crank angle sensor for detecting a crank angle signal from the second signal member. Provided.

  At this time, in order to control the ignition timing of the internal combustion engine, fuel injection, and the like, a signal synchronized with the rotation of the engine is used, and the first signal member is ½ of the rotation of the crankshaft. The rotation angle of the camshaft corresponds to the rotation angle of the camshaft whose phase changes with respect to the crankshaft by the variable valve timing mechanism, and can be detected by the cam angle sensor, and includes at least a cylinder discrimination signal (only that signal) And a cam angle signal generator (not shown) for generating a plurality of cam angle signals (including signals that can be discriminated by cylinders), the second signal member being detectable by the crank angle sensor, and In synchronization with the rotation of the crankshaft, a crank angle signal generator (not shown) that generates an angle signal for each first predetermined angle excluding a plurality of predetermined angle ranges and a first predetermined angle or less Comprising a toothless portion angle signal is not generated (not shown) over.

  The cam angle sensor signal generates a pulse signal at BTDC 75 degrees, 5 degrees of each cylinder and BTDC 210 degrees of the # 1 cylinder for cylinder identification so that the cylinder can be identified only by the signal when the most retarded angle is fixed. In addition, when the VVT mechanism is operated, a pulse signal advanced by 60 degrees at maximum is set. Also, the crank angle sensor signal generates a pulse signal every 10 degrees CA, and the predetermined # 1 cylinder BTDC 105 degrees, 115 degrees, # 3 cylinder BTDC 225 degrees, 235 degrees, # 2 cylinder BTDC 225 degrees, 235 Degrees and BTDC 105 degrees and 115 degrees are set as missing teeth (not shown) so as not to generate a pulse signal. A time chart of the cam angle sensor signal and the crank angle sensor signal of the three-cylinder internal combustion engine is disclosed in FIG.

  The crank angle sensor signal generates a pulse signal every 10 degrees CA which is the first predetermined angle, and the predetermined # 1 cylinder BTDC 105 degrees, 115 degrees, # 3 cylinder BTDC 225 degrees, 235 degrees, # 2 cylinder BTDC 225 degrees, 235 degrees, and BTDC 105 degrees, 115 degrees are set as missing teeth (not shown) so as not to generate a pulse signal. The cam angle sensor signal generates a pulse signal at BTDC 75 degrees and 5 degrees for each cylinder and BTDC 210 degrees for the cylinder # 1 for cylinder identification, and a pulse signal advanced by a maximum of 60 degrees when the VVT mechanism is activated. Set to

  The missing tooth portion is composed of a first missing tooth portion and a second missing tooth portion, and the number of angle signals generated along the rotation direction of the crank angle is from the first missing tooth portion to the second missing tooth portion. Of the angle signal generated between the missing tooth portions of the second signal member is provided at a position where the number detected in the second tooth missing portion and the number detected from the second missing tooth portion to the first missing tooth portion are different. A cylinder discriminating means 4 for discriminating a cylinder from the number and the number of cam angle signals is provided.

  More specifically, the cylinder discriminating apparatus 2 of the internal combustion engine, as shown in FIG. 1, receives a crank angle sensor signal and performs a missing tooth determination unit 6 and a cam angle sensor signal as a temporary input. Temporary cylinder determining unit 8 for determining a cylinder, crank angle signal abnormality determining unit 10, cam angle signal abnormality determining unit 12, cylinder determining means 4 for determining a cylinder based on those results, and each cylinder determining result And a cylinder discrimination selection unit 14 that determines which cylinder discrimination result to use based on the cylinder discrimination result.

  The cylinder discriminating means 4 has a function that can be carried out when the engine is started while the variable valve timing mechanism is not in operation.

  Further, the cylinder discriminating means 4 counts the number of angle signals generated between the missing tooth portions of the second signal member and the angle signal between the missing tooth portions when the variable valve timing mechanism is in operation. The cylinder is discriminated from the cam angle signal value (provisional cylinder discrimination result) immediately before the start.

  Further, when the crank angle sensor fails, the cylinder discriminating means 4 stops the VVT advance angle control and discriminates the cylinder only by the cam angle sensor signal at the most retarded position. Furthermore, the cylinder discriminating means 4 discriminates the cylinder only by the crank angle sensor when the cam angle sensor fails.

  Further, the missing tooth portion has a region for two signals in the angle signal.

  In addition, as shown in FIG. 1, the cylinder discriminating means 4 includes a first cylinder discriminating means 16 that is executed only when the engine is not advanced by the VVT mechanism based on the result of each judgment section, and an engine start time. To the second cylinder discriminating means 18 that is normally operated including the advance angle of the VVT mechanism, and the third cylinder discriminating means 20 when the cam angle signal is abnormal.

  The missing tooth determination unit 6 is activated each time a crank angle sensor signal is input, and as shown in FIG. 3, the crank angle input between cam angle sensor signal pulses is input to determine crank angle signal abnormality. The number of angle sensor signal pulses CRICNT is counted up, and it is confirmed that at least three pulses of the crank angle sensor signal are input in order to perform the missing tooth determination, and the missing tooth determination time chart of the crank angle sensor signal in FIG. As shown, for example, the ratio (TCR0 / TCR1) between the latest pulse signal input interval time TCR0 and the previous pulse signal input interval time TCR1 is calculated. judge. On the contrary, when it is not a missing tooth, it has a function of counting up a crank angle sensor signal pulse inputted during missing tooth determination, that is, the number CRCNT of crank angle signals.

The provisional cylinder determination unit 8 is activated every time a cam angle sensor signal is input. As shown in FIG. 5, when a cam angle sensor signal pulse is input, the provisional cylinder determination unit 8 counts up the number of cam angle signals CMCNT. As shown in the provisional cylinder discrimination time chart of the cam angle sensor signal in FIG. 6, for example, the latest pulse signal input interval time TCM0 and the previous pulse signal are confirmed. The result calculated by the input interval time TCM1 and the previous pulse signal interval time TCM2 is
TCM2 / TCM0 ≧ K2 (K2: for example, 3)
In the case of # 1 cylinder BTDC 210 degrees,
TCM1 / TCM2 X TCM0 / TCM2 ≧ K3 (K3: 4 for example)
In this case, it has a function of determining BTDC 5 degrees of the # 1 cylinder.

  Further, the crank angle signal abnormality detection unit 10 is activated every time a cam angle sensor signal is input, and when two or more pulses of the cam angle sensor signal are input as shown in FIG. When the number of crank angle sensor signal pulses CRICNT input to CRICNT is 0, CRFCNT is counted up as an abnormality, and when abnormality is detected twice in succession, it has a function of determining that the crank angle sensor signal is abnormal. .

  Furthermore, the cam angle signal abnormality detection unit 12 is activated every time the missing tooth determination of the crank angle signal is completed, and as shown in FIG. 8, the cam angle input between the previous missing tooth determination and the current missing tooth determination. When the number of sensor signal pulses, that is, the number of cam angle signals CMCNT is 0, CMFCNT is counted up as an abnormality, and when an abnormality is detected three times in succession, a cam angle sensor signal abnormality is determined. .

  As shown in FIG. 9, the first cylinder discriminating means 16 at the time of start, in which the VVT mechanism of the cylinder discriminating means 4 does not advance, is activated every time the missing tooth determination based on the crank angle sensor signal is completed. The combination of the number of crank angle signals CRCNT that is the count value of the crank angle sensor signal pulses and the number of cam angle signals CMCNT that is the count value of the cam angle sensor signal pulses input during the present missing tooth determination (see FIG. 10). ) To determine the cylinder.

  For example, when the number of crank angle signals CRCNT is 20 or more and the number of cam angle signals CMCNT is 3, as shown in FIG. 10, it is determined that the BTDC is 95 degrees for the # 1 cylinder, and depending on the crank angle position. The cylinder discrimination code CYLID1 is set to 1.

  If neither condition is met, the cylinder discrimination is not completed and the cylinder discrimination code CYLID1 is set to 0.

  However, it is not performed when the normal cylinder discrimination described below has already been completed or when the advance amount by the VVT mechanism is not zero.

  Further, the second cylinder discrimination means 18 in the normal state in which the advance of the VVT mechanism of the cylinder discrimination means 4 is started every time the missing tooth determination by the crank angle sensor signal is completed, as shown in FIG. The cylinder is determined by a combination (see FIG. 12) of the crank angle signal number CRCNT, which is the count value of the crank angle sensor signal pulse input between the tooth determination and the current missing tooth determination, and the provisional cylinder determination result by the cam angle sensor signal. It has a function to discriminate.

  For example, if the number of crank angle signals CRCNT is 20 or more and the provisional cylinder discrimination result of the cam angle sensor signal input immediately before it is BTDC 210 degrees for the # 1 cylinder or BTDC 75 degrees, the BTDC 95 for the # 1 cylinder The cylinder discrimination code CYLID2 corresponding to the crank angle position is set to 1.

  However, when neither of the conditions is satisfied, the cylinder discrimination is not completed and the cylinder discrimination code CYLID2 is set to 0.

  When the cylinder determination by the missing tooth determination is completed, the completion of the missing tooth determination is cleared, and the number of crank angle signals CRCNT and the number of cam angle signals CMCNT are cleared.

  Further, as shown in FIG. 13, the third cylinder discriminating means 20 when it is judged that the cam angle signal abnormality of the cylinder discriminating means 4 is started up every time the missing tooth determination by the crank angle sensor signal is completed, and the cam angle signal abnormality occurs. In this case, the number of crank angle signals CRCNT, which is the count value of the crank angle sensor signal pulse input between the previous missing tooth determination and the current missing tooth determination, and the pulse signal cycle at the previous missing tooth determination It has a function of discriminating cylinders by comparing with the pulse signal cycle determined this time.

  FIG. 14 discloses changes in engine rotation speed during cranking. The engine rotation speed during cranking is not constant, and the rotation speed decreases near the compression top dead center (TDC) of each cylinder.

  In FIG. 14, the number of crank angle signals CRCNT is 20 or more (A) section missing tooth determination position # 2 cylinder BTDC 95 degrees, # 1 cylinder BTDC 95 degrees and (C) section # 3 cylinder BTDC 215 degrees # 2 Cylinder BTDC 215 degrees is the same crank position, so there is no significant change in rotational speed except when cranking is started, but the number of crank angle signals CRCNT is 12 or less (B) Missing tooth Judgment position There is a large change in rotational speed between BTDC 95 degrees of cylinder # 1 and BTDC 215 degrees of cylinder # 3, and # 2 cylinder BTDC 215 degrees and # 2 cylinder BTDC 95 degrees of section (D).

  Therefore, when the number of crank angle signals CRCNT is 12 or less and a missing tooth determination is made, the pulse signal cycle TCROLD at the previous missing tooth determination is compared with the current pulse signal cycle TCRNEW, and the current pulse signal cycle TCRNEW is compared. Is greater than BTDC 215 degrees for the # 3 cylinder, and if the current pulse signal period TCRNEW is smaller, it is determined to be BTDC 95 degrees for the # 2 cylinder, and when the cylinder discrimination is completed, the cylinder discrimination code CYLID3 is set. Set to 1.

  Here, the second cylinder discriminating means 18 at the normal time when the advance of the VVT mechanism of the cylinder discriminating means 4 is performed determines which one of the above-mentioned cylinder discrimination results is selected as shown in FIG.

  First, in the case of cam angle signal abnormality, if cylinder discrimination based only on the crank angle signal is completed, ignition timing control and fuel dark control are performed based on the result.

  If the crank angle sensor signal is abnormal and the provisional cylinder discrimination is completed, the advance control of the VVT mechanism is stopped and the control is performed based on the provisional cylinder discrimination result.

Crank angle sensor signal is normal, and normal cylinder discrimination is completed. CYLID2 ≠ 0
In this case, control is performed according to the normal cylinder discrimination result.

Completion of cylinder discrimination at normal time CYLID2 = 0
In addition, the cylinder discrimination at the start is completed. CYLID1 ≠ 0
In this case, the control is performed according to the cylinder discrimination result at the time of starting.

  However, if neither of the conditions is met, the ignition timing control and the fuel injection control are not started because the cylinder discrimination is not completed.

  Next, the operation will be described.

  First, a description will be given along the missing tooth determination flowchart of FIG.

  Each time a crank angle sensor signal is input to the missing tooth determination unit 6, a missing tooth determination program is started. When this missing tooth determination program starts (100), CRICNT is set to determine crank angle signal abnormality. The counter is counted up (102), and the third pulse input of the crank angle sensor signal, that is, the determination (104) of whether or not three or more pulses of the crank angle sensor signal are input is entered.

  If the determination (104) is YES, as shown in the missing tooth determination time chart of the crank angle sensor signal in FIG. 4, the latest pulse signal input interval time TCR0 and the previous pulse signal input interval time TCR1 are shown. When the ratio (TCR0 / TCR1) is calculated and the ratio is equal to or greater than the determination value K1 (K1: for example 2), the process proceeds to determination (106), and the above determination (104) is NO. Shifts to a process (112) for replacing the latest pulse signal input interval time TCR0 described later with the previous pulse signal input interval time TCR1.

  In the determination (106) of whether or not the ratio (TCR0 / TCR1) ratio between the latest pulse signal input interval time TCR0 and the previous pulse signal input interval time TCR1 is 2 or more, this determination (106) is YES In this case, the determination of missing teeth is completed (108), and when the determination (106) is NO, the number CRCNT of crank angle signals, which are crank angle sensor signal pulses input during missing tooth determination, is counted up. After (110), processing (108) and (110), processing (112) for replacing the latest pulse signal input interval time TCR0 with the previous pulse signal input interval time TCR1 is performed, and RTS (114) which is the end Migrate to

  Description will be made along the provisional cylinder discrimination flowchart of FIG.

  Each time a cam angle sensor signal is input to the provisional cylinder discrimination unit 8, a provisional cylinder discrimination program is started. When this provisional cylinder discrimination program starts (200), the number of cam angle signals CMCNT is counted up ( 202) The pulse input of the cam angle sensor signal is shifted to the fourth or later, that is, the determination (204) of whether or not four pulses or more have been input from the start of engine start.

  If the determination (204) is YES, as shown in the temporary cylinder discrimination time chart of the cam angle sensor signal in FIG. 6, the previous pulse signal interval time TCM2 and the latest pulse signal input interval time TCM0 When the ratio (TCM2 / TCM0) is equal to or greater than the determination value K2 (K2: for example 3), the process proceeds to determination (206). When the determination (204) is NO, the latest pulse signal input described later is input. The processing shifts to a process (218) in which the interval time TCM0 is replaced with the previous pulse signal input interval time TCM1, and the previous pulse signal input interval time TCM1 is replaced with the previous pulse signal interval time TCM2.

  In the determination (206) of whether or not the ratio (TCM2 / TCM0) between the latest pulse signal input interval time TCM0 and the previous pulse signal interval time TCM2 is equal to or greater than the determination value K2 (K2: 3), for example. If the determination (206) is YES, it is determined that the BTDC is 210 ° CA of the # 1 cylinder (208), the provisional cylinder determination is completed (210), and if the determination (206) is NO, the previous one The ratio of the pulse signal input interval time TCM1 to the previous pulse signal interval time TCM2 (TCM1 / TCM2) and the latest pulse signal input interval time TCM0 to the previous pulse signal interval time TCM2 (TCM0 / TCM2) Shifts to a determination (212) as to whether or not the product of is greater than or equal to a determination value K3 (K3: for example, 4).

  If this determination (212) is YES, it is determined that the BTDC is 5 ° CA of the # 1 cylinder (214), and the process proceeds to the provisional cylinder discrimination completion (210). If the determination (212) is NO, the provisional cylinder The process proceeds to discrimination incomplete (216), and after the provisional cylinder discrimination completion (210) and provisional cylinder discrimination incomplete (216), the latest pulse signal input interval time TCM0 is replaced with the previous pulse signal input interval time TCM1. Then, a process (218) for replacing the previous pulse signal input interval time TCM1 with the previous pulse signal interval time TCM2 is performed (218), and the process proceeds to the end RTS (220).

  A description will be given along the crank angle signal abnormality determination flowchart of FIG.

  Each time a cam angle sensor signal is input to the crank angle signal abnormality detection unit 10, a crank angle signal abnormality determination program is started. When the crank angle signal abnormality determination program starts (300), the cam angle sensor signal is The process proceeds to determination (302) of whether or not two or more pulses have been input.

  If this determination (302) is YES, the routine proceeds to determination (304) on whether or not the number CRICNT of crank angle sensor signal pulses input between cam angle sensor signal pulse inputs is zero. If (302) is NO, the process proceeds to RTS (318) which is an end described later.

  In the determination (304) of whether or not the number of crank angle sensor signal pulses CRICNT input between cam angle sensor signal pulse inputs is 0, if this determination (304) is YES, the crank angle signal is abnormal. When the determination (304) is NO, the process proceeds to the crank angle signal abnormality determination clear process (308).

  After the above-described process (306) for counting up CRFCNT, it is determined (310) whether CRFCNT is 2 or more, that is, whether an abnormality has been detected continuously twice or more, and this determination (310) is YES. In this case, the process (314) of replacing the value obtained by subtracting 1 from CRFCNT with a new CRFCNT is performed through the process (312) of crank angle signal abnormality determination completion, and when the determination (310) is NO, After the crank angle signal abnormality determination clear process (308), a process (316) for replacing 0 with CRICNT and CRFCNT is performed, and after the processes (314) and (316), the process shifts to the end RTS (318).

  A description will be given along the flowchart for determining cam angle signal abnormality in FIG.

  The cam angle signal abnormality determining program of the cam angle signal abnormality detecting unit 12 is started every time the crank angle signal missing tooth determination is completed, and when the cam angle signal abnormality determining program starts (400), the previous missing tooth determination is performed. From this time, the process proceeds to the determination (402) of whether or not the number of cam angle signals CMCNT, which is the number of cam angle sensor signal pulses input during this missing tooth determination, is zero.

  In this determination (402), if the determination (402) is YES, it is determined that the cam angle signal is abnormal, the process proceeds to the process (404) for counting up CMFCNT, and the determination (402) is NO. The process proceeds to the cam angle signal abnormality determination clear process (406).

  After the above-described process (404) for counting up CMFCNT, it is determined whether CMFCNT is 3 or more, that is, whether abnormality has been detected three times in succession (408). If this determination (408) is YES After the cam angle signal abnormality determination completion process (410), a process (412) for replacing the value obtained by subtracting CMFCNT or 1 with a new CMFCNT is performed, and if the determination (408) is NO, After processing for clearing angular signal abnormality determination (406), processing for replacing 0 with CMFCNT (414) is performed, and after processing (412) and (414), the process proceeds to RTS (416) which is an end.

  A description will be given along the cylinder discrimination flowchart at the start of FIG.

  The cylinder discriminating program at the start of the first cylinder discriminating means 16 at the start without performing advance of the VVT mechanism of the cylinder discriminating means 4 is started every time the missing tooth determination by the crank angle sensor signal is completed. When the cylinder discrimination program is started (500), it is determined (502) whether or not the cylinder discrimination code CYLID2 is 0. If this determination (502) is YES, the advance amount of the VVT mechanism is 0. When the determination (502) is NO, the process proceeds to a process (506) in which 0 is replaced with the cylinder determination code CYLID1 because the cylinder determination is not completed.

  In the determination (504) of whether or not the advance amount of the VVT mechanism is 0, if this determination (504) is YES, it is determined whether or not the number CRCNT of crank angle signals is 20 or more. If the determination (504) is NO, the process shifts to a process (506) in which 0 is replaced with the cylinder determination code CYLID1 because the cylinder determination is not completed.

  In the determination (508) of whether or not the number of crank angle signals CRCNT is 20 or more (508), if this determination (508) is YES, the number of cam angle signals that is the count value of the cam angle sensor signal pulse. The process proceeds to judgment (510) on whether or not CMCNT is 3, and if judgment (508) is NO, the process proceeds to judgment (512) on whether or not the number of crank angle signals CRCNT is 12 or less. .

  In the determination (510) of whether or not the number of cam angle signals CMCNT, which is the count value of the cam angle sensor signal pulse described above, is 3, if this determination (510) is YES, BTDC of the # 1 cylinder is 95 °. It is determined as CA (514), the cylinder discrimination code CYLID1 corresponding to the crank angle position is set to 1 (516), and if the determination (510) is NO, the cam angle which is the count value of the cam angle sensor signal pulse The process proceeds to determination (518) of whether the number of signals CMCNT is two.

  In the determination (518) of whether or not the number of cam angle signals CMCNT, which is the count value of the cam angle sensor signal pulse, is 2, if the determination (518) is YES, BTDC 215 ° CA of the # 2 cylinder is A determination is made (520), the cylinder discrimination code CYLID1 corresponding to the crank angle position is set to 3 (522), and if the decision (518) is NO, the cylinder discrimination is not completed and 0 is replaced with the cylinder discrimination code CYLID1 Move to (506).

  Further, in the determination (512) of whether or not the number of crank angle signals CRCNT is 12 or less, if this determination (512) is YES, the cam angle signal which is the count value of the cam angle sensor signal pulse. When the determination (512) is NO, the process proceeds to a process (506) in which 0 is replaced with the cylinder determination code CYLID1 when the determination (512) is NO. .

  In the determination (524) of whether or not the number of cam angle signals CMCNT that is the count value of the cam angle sensor signal pulse is 2 (524), if this determination (524) is YES, BTDC 215 ° of # 3 cylinder It is determined as CA (526), the cylinder discrimination code CYLID1 corresponding to the crank angle position is set to 2 (528), and when the determination (524) is NO, the cam angle which is the count value of the cam angle sensor signal pulse The process proceeds to determination (530) of whether the number of signals CMCNT is zero.

  In the determination (530) of whether or not the number of cam angle signals CMCNT which is the count value of the cam angle sensor signal pulse is 0 (530), if the determination (530) is YES, BTDC 95 ° CA of # 2 cylinder A determination is made (532), the cylinder discrimination code CYLID1 corresponding to the crank angle position is set to 4 (534), and if the determination (530) is NO, the cylinder discrimination is not completed and 0 is replaced with the cylinder discrimination code CYLID1 Move to (506).

  After the end of the processes (516), (522), (528), (534), and (506), the process proceeds to the end RTS (536).

  Description will be made along the normal cylinder discrimination flowchart of FIG.

  The cylinder discriminating program at the time of starting the second cylinder discriminating means 18 at the normal time when the advance of the VVT mechanism of the cylinder discriminating means 4 is performed is started every time the missing tooth determination by the crank angle sensor signal is completed, The cylinder is determined by a combination (see FIG. 12) of the crank angle signal number CRCNT, which is the count value of the crank angle sensor signal pulse input between the tooth determination and the current missing tooth determination, and the provisional cylinder determination result by the cam angle sensor signal. Determine.

  That is, when the cylinder discrimination program at the start is started (600), the process proceeds to the determination (602) as to whether or not the provisional cylinder discrimination is completed. If this determination (602) is YES, the determination from the previous missing tooth determination is made. The process proceeds to the determination (604) of whether or not the number CRCNT of crank angle signals, which is the count value of the crank angle sensor signal pulse input during the current missing tooth determination, is 20 or more, and the determination (602) is NO. In this case, the cylinder discrimination code CYLID2 is set to 0 because the cylinder discrimination is not completed (606).

  In the determination (604) of whether or not the number CRCNT of crank angle signals, which is the count value of the crank angle sensor signal pulse input between the previous missing tooth determination and the current missing tooth determination, is 20 or more. If this determination (604) is YES, whether or not the temporary cylinder determination result of the cam angle sensor signal input immediately before the missing tooth determination this time is BTDC 210 ° CA or BTDC 75 ° CA of the # 1 cylinder. When the determination (608) is entered and the determination (604) is NO, the number of crank angle signals that are the count values of the crank angle sensor signal pulse input between the previous missing tooth determination and the current missing tooth determination. The process proceeds to determination 610 of whether CRCNT is 12 or less.

  In the determination (608) of whether or not the temporary cylinder determination result of the cam angle sensor signal is BTDC 210 ° CA or BTDC 75 ° CA of the # 1 cylinder, if this determination (608) is YES, BTDC 95 of the # 1 cylinder The process proceeds to the process for determining ° CA (612). If the determination (608) is NO, the process proceeds to determination (614) as to whether or not # 3 cylinder BTDC is 5 ° CA.

  After the above-described process for determining # 1 cylinder BTDC 95 ° CA (612), the cylinder discrimination code CYLID2 corresponding to the crank angle position is set to 1 (616), and the missing tooth determination completion clear process (618) is performed. The number of crank angle signals CRCNT, which is the count value of the crank angle sensor signal pulse input between the previous missing tooth determination and the current missing tooth determination, and the cam angle signal, which is the count value of the cam angle sensor signal pulse, are set to 0. The process shifts to a process (620) for resetting the number CMCNT, and then shifts to an RTS (638) which is an end described later.

  In the determination (614) of whether or not the provisional cylinder determination result of the cam angle sensor signal is BTDC 5 ° CA of the # 3 cylinder, if this determination (614) is YES, the BTDC 215 of the # 2 cylinder is determined. Shift to processing (622) for determining CA, cylinder discrimination code CYLID2 corresponding to the crank angle position is set to 3 (624), processing for clearing missing tooth determination completion (618) is performed, and previous missing tooth determination is performed To reset the number of crank angle signals CRCNT, which is the count value of the crank angle sensor signal pulses, and the number of cam angle signals CMCNT, which is the count value of the cam angle sensor signal pulses, which are input during the missing tooth determination from this time (620) ) And then to RTS (638), which is an end, which will be described later, and if the determination (614) is NO, the cylinder determination is not completed. The cylinder discrimination code CYLID2 is set to 0 (606).

  Further, in the determination (610) whether the number CRCNT of crank angle signals, which is the count value of the crank angle sensor signal pulse input between the previous missing tooth determination and the current missing tooth determination, is 12 or less. If this determination (610) is YES, the process proceeds to determination (626) as to whether or not the provisional cylinder determination result of the cam angle sensor signal input immediately before is BTDC 5 ° CA of the # 1 cylinder. If (610) is NO, the cylinder discrimination code CYLID2 is set to 0 because the cylinder discrimination is not completed (606).

  In the determination (626) of whether or not the temporary cylinder determination result of the cam angle sensor signal is BTDC 5 ° CA of the # 1 cylinder, if this determination (626) is YES, the # 3 cylinder BTDC 215 ° CA is determined. Is shifted to the process (628) for determining the cylinder angle, the cylinder determination code CYLID2 corresponding to the crank angle position is set to 2 (630), and if the determination (626) is NO, the temporary cylinder determination of the cam angle sensor signal is performed. The process proceeds to determination (632) as to whether or not the result is BTDC 5 ° CA of # 3 cylinder or BTDC 75 ° CA of # 2 cylinder.

  In the determination (632) of whether the provisional cylinder determination result of the cam angle sensor signal is BTDC 5 ° CA of # 3 cylinder or BTDC 75 ° CA of # 2 cylinder, if the determination (632) is YES, # The process proceeds to the process of determining BTDC 95 ° CA of two cylinders (634), the cylinder determination code CYLID2 corresponding to the crank angle position is set to 4 (636), and if the determination (632) is NO, the cylinder determination The cylinder discrimination code CYLID2 is set to 0 as incomplete (606).

  After the completion of the processes (606), (630), and (636), the process proceeds to the end RTS (638).

  Description will be made along the cylinder discrimination flowchart when the cam angle signal is abnormal in FIG.

  The cylinder discriminating program when the cam angle signal of the third cylinder discriminating unit 20 is abnormal when the cam discriminating unit 4 determines that the cam angle signal is abnormal is activated every time the missing tooth determination by the crank angle sensor signal is completed. When the cylinder discrimination program when the angular signal is abnormal starts (700), the process proceeds to judgment (702) of whether or not the cam angular signal is abnormal.

  In the determination (702) of whether or not this cam angle signal is abnormal, if the determination (702) is YES, the count value of the crank angle sensor signal pulse input between the previous missing tooth determination and the current missing tooth determination. The process proceeds to a determination (704) as to whether or not the number CRCNT of a certain crank angle signal is 12 or less. If the determination (702) is NO, the cylinder determination code CYLID3 is set to 0 as incomplete cylinder determination ( 706), the process proceeds to RTS (716) which is an end described later.

  In the determination (704) of whether or not the number CRCNT of crank angle signals, which is the count value of the crank angle sensor signal pulse input between the previous missing tooth determination and the current missing tooth determination, is 12 or less. If this determination (704) is YES, the process proceeds to determination (708) as to whether or not the current pulse signal cycle TCNEW is greater than the pulse signal cycle TCROLD at the previous missing tooth determination. If NO in step 704, the process proceeds to the end RTS (716).

  Also, in the determination (708) of whether or not the current pulse signal cycle TCRNEW is larger than the pulse signal cycle TCROLD at the time of the previous missing tooth determination, if this determination (708) is YES, the # 3 cylinder When the determination (708) is NO, the process proceeds to a process (712) for determining # 2 cylinder BTDC 95 ° CA, and these processes (710) are performed. ) And (712), the cylinder discrimination is completed. Therefore, the cylinder discrimination code CYLID3 is set to 1 (714), and the process proceeds to the end RTS (716).

  A description will be given along the flowchart for selecting cylinder discriminating means in FIG.

  When the cylinder discriminating means selection program of the cylinder discriminating / selecting section 14 starts (800), the routine proceeds to judgment (802) on whether or not the cam angle signal is abnormal.

  In the determination of whether or not the cam angle signal is abnormal (802), if the determination (802) is NO, the process proceeds to determination (804) whether or not an abnormality in the crank angle signal has been detected, and the determination (802) is YES. In this case, the routine proceeds to judgment (806) as to whether or not the cylinder discrimination code CYLID3 when the cam angle signal is abnormal is not zero.

  In the determination whether the crank angle signal abnormality is detected (804), if this determination (804) is YES, the process proceeds to the determination (808) as to whether or not the provisional cylinder determination is completed. If (804) is NO, the routine proceeds to judgment (810) as to whether or not the cylinder discrimination code CYLID2, which is a normal cylinder discrimination completion code, is not zero.

  In the determination (808) of whether or not the above-described provisional cylinder determination is completed, if this determination (808) is YES, the VVT mechanism advance control is stopped, that is, the advance control by the VVT mechanism is stopped. Control is performed based on the provisional cylinder discrimination result (814), the process proceeds to RTS (826), which is an end described later, and if the determination (808) is NO, cylinder discrimination incomplete processing (824) described later is performed. To RTS (826) as the end.

  In the determination (810) of whether or not the cylinder determination code CYLID2, which is the normal cylinder determination completion code described above, is 0, if this determination (810) is YES, the process of adopting the normal cylinder determination result is adopted. In other words, the process shifts to the process (816) for performing the control according to the cylinder discrimination result at the normal time, shifts to the RTS (826) as the end, and when the judgment (810) is NO, the cylinder discrimination at the start is completed. The routine proceeds to judgment (818) on whether or not the cylinder discrimination code CYLID1 is not 0.

  Further, in the determination (818) of whether or not the cylinder determination code CYLID1 that is the cylinder determination completion at the time of start is not 0, when this determination (818) is YES, the process of adopting the cylinder determination result at the start, In other words, the process shifts to the process (820) for performing control according to the cylinder determination result at the start, shifts to the end RTS (826), and if the determination (818) is NO, the cylinder determination incomplete process ( 824) and then the RTS (826) which is the end.

  Furthermore, in the determination (806) of whether or not the cylinder determination code CYLID3 when the cam angle signal is abnormal is not 0, when this determination (806) is YES, the result of the cylinder determination when the cam angle signal is abnormal is shown. The recruitment process (822) is performed and the process proceeds to the end RTS (826). If the determination (806) is NO, the process proceeds to the cylinder discrimination incomplete process (824), and then the end RTS. Move to (826).

  Thereby, the cylinder discrimination of the internal combustion engine provided with the camshaft having the first signal member, the cam angle sensor, the crankshaft having the second signal member, the crank angle sensor, and the variable valve timing mechanism. In the apparatus, the first signal member includes a cam angle signal generation unit that generates a plurality of cam angle signals that can be detected by a cam angle sensor and includes at least a cylinder discrimination signal, and the second signal member includes: A crank angle signal generating section that can be detected by a crank angle sensor and that generates an angle signal for each first predetermined angle excluding a plurality of predetermined angle ranges in synchronization with rotation of the crankshaft, and a first predetermined angle A missing tooth portion that does not generate an angle signal over the above is provided, and this missing tooth portion is composed of a first missing tooth portion and a second missing tooth portion, and an angle signal generated along the rotation direction of the crank angle. Number The second signal member is provided at a position where the number detected from the first missing tooth portion to the second missing tooth portion is different from the number detected from the second missing tooth portion to the first missing tooth portion. By providing a cylinder discriminating means for discriminating a cylinder from the number of angle signals generated between the tooth missing portions and the number of cam angle signals, the number of crank angle signals generated between the tooth missing portions and the cam angle signal are provided. Therefore, the time required for cylinder determination can be shortened.

  Further, the cylinder discrimination means can be implemented at the time of starting the engine when the variable valve timing mechanism is not operated, so that the cylinder can be discriminated at an early stage when starting the engine. Can be realized.

  Further, when the variable valve timing mechanism is in operation, the number of angle signals generated between the missing tooth portions of the second signal member and the cam angle signal value immediately before counting the angle signals between the missing tooth portions. Thus, the cylinder can be identified early even when the variable valve timing mechanism is in operation. Further, when the crank angle sensor fails, the cylinder determining means can stop the VVT advance control and determine the cylinder only by the cam angle sensor signal at the most retarded position.

  Furthermore, when the cam angle sensor fails, the cylinder is determined only by the crank angle sensor, so that even when the cam angle sensor is broken, the cylinder can be determined only by the crank angle sensor.

  In addition, since the missing tooth portion has a region corresponding to two signals in the angle signal, the missing tooth portion and the other angle signal generating portion are erroneously determined even in a state in which the rotational fluctuation of the engine speed is large. Therefore, highly accurate cylinder discrimination control can be performed.

1 is a block diagram of a cylinder discrimination device for an internal combustion engine showing an embodiment of the present invention. 3 is a time chart of a cam angle sensor signal and a crank angle sensor signal of a three-cylinder internal combustion engine. It is a flowchart for a missing tooth determination. It is a missing tooth determination time chart of a crank angle sensor signal. It is a flowchart for temporary cylinder discrimination. It is a provisional cylinder discrimination time chart of a cam angle sensor signal. It is a flowchart for crank angle signal abnormality determination. It is a flowchart for cam angle signal abnormality determination. It is a flowchart for cylinder discrimination at the time of starting. It is a cylinder discrimination table at the time of start (no VVT advance angle). It is a flowchart for cylinder discrimination at the normal time. It is a cylinder discrimination table at the normal time (with VVT advance angle). It is a flowchart for cylinder discrimination at the time of cam angle signal abnormality. It is a figure which shows the engine speed change at the time of cranking. It is a flowchart for cylinder discrimination means selection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Cylinder discrimination | determination apparatus of an internal combustion engine 4 Cylinder discrimination | determination means 6 Missing tooth determination part 8 Temporary cylinder determination part 10 Crank angle signal abnormality determination part 12 Cam angle signal abnormality determination part 14 Cylinder discrimination | determination selection part 16 1st cylinder discrimination means 18 2nd cylinder Discriminating means 20 Third cylinder discriminating means

Claims (2)

In a cylinder discrimination device for an internal combustion engine comprising a camshaft having a first signal member, a cam angle sensor, a crankshaft having a second signal member, a crank angle sensor, and a variable valve timing mechanism,
The first signal member includes a cam angle signal generation unit that generates a plurality of cam angle signals that can be detected by the cam angle sensor and includes at least a cylinder discrimination signal;
The second signal member is a crank that can be detected by the crank angle sensor and that generates an angle signal for each first predetermined angle except for a plurality of predetermined angle ranges in synchronization with rotation of the crankshaft. An angular signal generator and a missing tooth portion that does not generate an angle signal over a first predetermined angle;
This missing tooth portion is composed of a first missing tooth portion and a second missing tooth portion, and the number of angle signals generated along the rotation direction of the crank angle is from the first missing tooth portion to the second missing tooth portion. And the number detected from the second missing tooth part to the first missing tooth part are different from each other,
A cylinder discriminating means for discriminating a cylinder from the number of angle signals generated between the toothless portions of the second signal member and the number of cam angle signals ;
In a state where the variable valve timing mechanism is operating, from the number of angle signals generated between the tooth missing portions of the second signal member and the cam angle signal value immediately before counting the angle signals between the tooth missing portions. cylinder identifying apparatus for an internal combustion engine, characterized in that to determine the cylinder.   The cylinder determining apparatus for an internal combustion engine according to claim 1, wherein the toothless portion includes a region corresponding to two signals in the angle signal.

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