JP2009085080A - Engine cylinder identification device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine cylinder identification device capable of identifying each cylinder, even if the signal obtained from one sensor is abnormal, only with the signals from the remaining normal sensors. <P>SOLUTION: The outer circumference of a crank signal plate has an equally spaced section on which a number of parts to be detected, including teeth and projections, are arranged over a predetermined angular range and at least two types of unequally spaced sections each covering a wider angular range than the equally spaced section, a number of parts to be detected, including teeth and projections, are disposed on the outer circumference of a cam signal plate, the cam signal plate is divided into as many areas as the number of cylinders, each of the areas is further divided into at least three regions α, β, γ, a part to be detected is disposed at a predetermined angular position in each of the regions α, β, γ, and the parts to be detected, disposed in the regions α, β, are set such that the combination of items of binarized bit information generated by the two parts to be detected varies with every cylinder. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cylinder determination device for an engine that determines which cylinder is in a specific stroke based on a signal obtained from a rotation angle sensor such as a crank angle sensor in a multi-cylinder engine, and more particularly, to a crank angle sensor. Alternatively, the present invention relates to a cylinder determination device for an engine that enables cylinder determination even if an abnormality occurs in one of cam angle sensors (a signal from the cam angle sensor).

  The engine has one cycle of operation in a plurality of strokes, for example, 2 or 4. For this reason, in a multi-cylinder engine having two or more cylinders, any cylinder is used for controlling ignition timing, fuel injection timing, and the like. Must be identified in a specific stroke, for example, a compression stroke, and therefore a cylinder determination device is required.

  Such a cylinder determination device usually includes a rotation angle sensor such as a crank angle sensor or a cam angle sensor. This rotation angle sensor is usually composed of a signal plate (circular rotating member) and a detector disposed in the vicinity of the outer periphery of the signal plate. For example, a large number of rotation angle sensors are provided on the outer periphery of the signal plate mounted on a rotating portion such as a crankshaft. Protrusions and the like (detected parts) are provided in a predetermined arrangement state, and the detector is configured to generate a pulse as a signal each time the detected part is detected, and based on a signal obtained from the detector Thus, the cylinder determination is performed by detecting a predetermined crank angle position of the predetermined cylinder. When the cylinder determination is performed with only one rotation angle sensor, if the signal obtained from the sensor is abnormal, the cylinder determination is impossible, the ignition timing and the fuel injection timing cannot be controlled, and the engine cannot be started.

  In order to cope with such an abnormal situation, for example, as disclosed in Patent Document 1, there is known one in which cylinder determination is performed based on signals obtained from three rotation angle sensors. Here, one sensor is composed of an equally spaced portion and an unequally spaced portion so that a signal A representing the same crank angle position can be obtained in a predetermined stroke of each cylinder. Thus, signals B and C representing different crank angle positions in a predetermined stroke of each cylinder are obtained, and when the signal A is abnormal, cylinder determination is performed from two signals B and C that are not abnormal. Has been proposed.

  Further, Patent Document 2 proposes that cylinder determination is performed by injecting fuel into a specific cylinder and detecting an initial explosion.

JP 2001-234895 A JP 2006-220097 A

  However, in the conventional cylinder determination device, the cylinder determination cannot be performed when the signals obtained from the two sensors are abnormal. That is, when performing cylinder determination based on signals obtained from a plurality of sensors, it is not possible to perform cylinder determination using only a signal obtained from one normal sensor. Even when the cylinder is determined by the first explosion generated by the fuel supply, the worst case is that the spark plug may be smoldered and the engine may not be started.

  The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to obtain from one remaining normal sensor when a signal obtained from one sensor is abnormal. Provides a cylinder determination device for an engine that can perform cylinder determination without error and without performing fuel injection only by a signal that is generated, and that can appropriately control ignition timing, fuel injection timing, etc. There is to do.

  In order to solve the above-described problems, an engine cylinder determination device according to the present invention includes a crank signal plate that is rotated integrally with an engine crankshaft and a detector that is disposed close to the outer periphery of the crank signal plate. One or a plurality of crank angle sensors, a cam signal plate that is rotated integrally with the camshaft of the engine, and one or a plurality of cam angle sensors that are arranged in proximity to the outer periphery of the cam signal plate. An engine cylinder determination device including a control unit that performs cylinder determination based on a signal obtained from the crank angle sensor and the cam angle sensor, wherein an outer periphery of the crank signal plate has teeth, protrusions, A large number of detected parts including concave parts, convex parts, holes, etc. are arranged over a predetermined angular range at equal angular intervals. An interval portion and at least two types of unequal interval portions having a larger angular interval than the equal interval portion and having different sizes, wherein the unequal interval portion is a number obtained by dividing 720 ° by the number of cylinders. The generated signal A corresponding to the unequal interval has an unequal interval portion arranged so as to be generated at the same crank angle position in the same stroke, and at the same time, on the outer periphery of the cam signal plate, The cam signal plate is divided into the same number of areas as the number of cylinders, and each area has at least three regions α, β, γ. In each of the regions α, β, and γ, a detected portion is installed at a predetermined angular position, and the detected portion installed in the region α and the region β All combinations of binarized bit information generated by the detection unit Characterized in that it is set to be different.

  In the engine cylinder determination device according to the present invention, at least two detected parts are provided in the region γ provided in the cam signal plate.

  Further, in the engine cylinder determining apparatus according to the present invention, when the crank angle sensor and the cam angle sensor are normal, the region α of the cam signal plate is detected after detecting the generated signal A detected by the crank angle sensor. And determining the cylinder according to the combination result of the detected part in the region β.

  In the engine cylinder determination device according to the present invention, when the crank angle sensor is abnormal and the cam angle sensor is normal, the cylinder determination is performed according to the arrangement of the detected parts installed on the cam signal plate. It is characterized by that.

  In addition, when the crank angle sensor is normal and the cam angle sensor is abnormal, the engine cylinder determination device according to the present invention has two types according to the number of detected equally spaced portions installed on the crank signal plate. It is characterized by discriminating unequal intervals and determining cylinder groups.

  In addition, when the crank angle sensor is abnormal and the cam angle sensor is normal, the cylinder determining apparatus for an engine according to the present invention is based on a cam angle signal in the region γ provided in the cam signal plate. The injection timing and the ignition energization start timing are set.

  The cylinder determination apparatus according to the present invention can perform cylinder determination without error only by signals obtained from the remaining normal rotation angle sensors when a signal obtained from one rotation angle sensor is abnormal. Therefore, ignition timing control and fuel injection timing control can be performed appropriately.

  An embodiment of an engine cylinder determination device of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram in which an embodiment of a cylinder determination device according to the present invention is applied to an in-vehicle in-line four-cylinder engine.

  In FIG. 1, an engine 1 includes a cylinder provided with four cylinders (# 1 to # 4) and a piston slidably inserted into each cylinder. An ignition plug is provided in a combustion chamber above the piston. (Connected to the ignition coil) 16 is provided, and an intake valve and an exhaust valve are provided. In addition, in the intake system (intake passage including the intake pipe 7), an air cleaner 31, an air flow sensor 2 for measuring the intake pipe pressure, a throttle body 4 having a throttle valve for adjusting the intake air amount, and an opening degree of the throttle valve are detected. A throttle sensor 6 and an idle speed control valve (ISC valve) 3 are disposed as appropriate, and an electronically controlled fuel injection valve 8 is provided in the intake pipe 7. The exhaust system is provided with an air-fuel ratio sensor 15, an exhaust purification catalytic converter, and the like.

  Although not shown, the fuel supply path is sucked out by a fuel pump, regulated by a pressure regulator through a fuel pipe, led to the fuel injection valve 8, and injected from the fuel injection valve 8 toward the intake port. The Further, as will be described in detail later, the engine 1 is provided with a crank angle sensor 18, a cam angle sensor 29, and a control unit (ECU) 100 used for cylinder determination.

  Signals from the air flow sensor 2, the throttle sensor 6, the air-fuel ratio sensor 15, the water temperature sensor 17, the crank angle sensor 18, the cam angle sensor 29, and the like are input to the control unit 100, and the control unit 100 is based on these signals. Thus, the fuel injection control by the fuel injection valve 8 and the ignition timing control by the spark plug 16 are performed.

  The crank angle sensor 18 is a hall-type sensor comprising a crankshaft signal plate that is rotated integrally with the crankshaft, and a crankshaft detector that is disposed close to the outer periphery of the signal plate. On the outer periphery of the plate, a plurality of detected parts made up of teeth, protrusions, concave parts, convex parts or holes are arranged at equal angular intervals (here, 10 ° CA) over a predetermined angular range; and The number of cylinders of the engine 1 is an unevenly spaced portion (tooth missing portion) in which at least two of the detected portions are arranged at an angular interval larger than the equally spaced portion (here, 30 ° CA and 40 ° CA). 1/2 (here, 2) are alternately provided. Therefore, a signal representing the tooth missing portion is received four times while the crankshaft rotates twice.

  The crankshaft detector captures changes in the magnetic field that occurs each time the detected part passes directly across it (detects the detected part), generates a pulse as a signal in an internal processing circuit, and controls this Supply to unit 100. Therefore, as shown in FIG. 3, the crankshaft detector (crank angle sensor 18) obtains a signal (reference signal) representing the same crank angle position in a predetermined process of each cylinder.

  The cam angle sensor 29 is a magnetic sensor comprising a cam shaft signal plate that is rotated integrally with the cam shaft, and a cam shaft detector disposed in the vicinity of the outer periphery of the signal plate. A plurality of detected parts made up of teeth, protrusions, concave parts, convex parts, holes or the like are provided at unequal intervals on the outer peripheral part of the plate. The cam shaft detector (cam angle sensor 29) captures a change in magnetic field that occurs every time the detected portion passes directly opposite (detects the detected portion), and outputs a pulse as a signal in an internal processing circuit. This is generated and supplied to the control unit 100. Therefore, from the cam angle sensor 29, as shown in FIG. 3, signals representing different crank angle positions in a predetermined process of each cylinder are obtained.

  FIG. 2 shows the internal configuration of the control unit 100. The control unit 100 includes a microcomputer including an input circuit 191, an A / D changing unit 192, a central processing unit 193, a ROM 194, a RAM 195, and an output circuit 196.

  When the input signal 190 is an analog signal (for example, a signal from the water temperature sensor 17, the throttle sensor 6, etc.), the input circuit 191 performs noise component removal from the input signal and outputs it to the A / D converter 192. It is. The central processing unit 193 has a function of executing the above-described controls and diagnoses by fetching the A / D conversion result and executing a fuel injection control program and other control programs stored in a medium such as the ROM 194. Yes. The calculation result and the A / D conversion result are temporarily stored in the RAM 195, and the calculation result is output as a control signal 197 through the output circuit 196 and used for controlling the fuel injection valve, the ignition coil, and the like. It is done.

  On the other hand, the signals of the crank angle sensor 18 and the cam angle sensor 29 are identified by the input circuit 191 as to the presence or absence of signals, and sent to the central processing unit 193 through the signal line 198 as a High / Low signal. The central processing unit 193 performs interrupt processing when the voltage level of the signal line 198 changes from Low to High, that is, at the falling timing of the crank angle sensor signal and the cam angle sensor signal in FIGS. It is the composition that is called.

  3 and 4 show the operation states of the respective parts when performing cylinder determination by the cylinder determination device of the present embodiment, that is, the strokes of the cylinders (# 1 to # 4), the crank angle sensor signal, and the cam angle sensor signal. It is the figure which showed the bit pattern generation state of the cylinder determination data from the generation | occurrence | production (arrival) state and the generation | occurrence | production (arrival) positional relationship of a crank angle sensor signal and a cam angle sensor signal.

  Hereinafter, the cylinder determination when the signal from the crank angle sensor 18 and the signal from the cam angle sensor 29 are normal will be described with reference to FIGS.

  FIG. 3 is a diagram showing the relationship among the crank angle sensor signal, the cam angle signal, and the strokes of the in-line four-cylinder engine when the engine rotates twice.

  FIG. 4 is a signal arrangement example of the crankshaft signal plate 18a and the camshaft signal plate 29a. On the outer periphery of these signal plates, a detection target portion including a plurality of convex portions that generate signals as shown in FIG. 3 is arranged.

  FIG. 5 is an example of the positional relationship between the crank angle signal and the cam angle signal for determining the cylinder.

  FIG. 6 is an identification example of cylinder discrimination (example of in-line four cylinders) using cam angle signals in the regions α and β based on the relationship shown in FIG.

  In the cylinder discrimination procedure, the reference crank angle (generated signal A) is detected from the signal information of the crank angle sensor 18, and the cylinder is discriminated based on the cam angle signal information detected within a predetermined crank angle from the generated signal A. .

  Next, the determination of the generated signal A that is the reference crank angle will be described. The crank angle signal has an equally spaced portion with a crank angle of 10 ° and an unequally spaced portion (tooth-missing portion) with a signal interval of 30 ° or 40 °. As shown in FIG. 5, there are two types of unequal intervals, BTDC 60 ° to 30 ° and BTDC 70 ° to 30 ° of the crank angle signal CR, starting from BTDC 30 °. This BTDC 30 ° corresponds to the reference crank angle (generated signal A).

  In order to determine BTDC 30 ° which is the reference crank angle, in other words, in order to determine the unequal interval portion, the signal interval time (time interval) of the crank angle sensor is measured every time the crank angle sensor signal is detected. The time interval CRT1 between the crank angle sensor signal of the previous time and the current crank angle sensor signal are compared. When CRT2 × coefficient (for example, 2) <CTR1 is satisfied, it is determined that the intervals are unequal, and the BTDC 30 ° signal (generated signal A) can be specified.

  As soon as the generation signal A can be specified, the cylinder determination is started. As shown in FIGS. 5 and 6, the cylinder determination is performed by pattern identification indicating at which timing the cam angle signal is input with respect to the reference crank angle. As shown in FIG. 5, since the reference crank angle is the starting point of BTDC 30 °, a crank angle region from there to a predetermined angle (30 ° in this example) is α (from BTDC 30 ° to TDC), and a predetermined angle ( In this example, a crank angle region up to 30 ° is defined as β (TDC to ATDC 30 °). Further, γ is assumed to be other than α and β.

  The cylinder discrimination signal is set in the α and β regions of the camshaft signal plate 29a as shown in FIG. 4, and in this example, the position of BTDC 10 ° in the α region. Are installed at a position of BTDC 160 ° (ATDC 20 °) in the β region.

  Then, as shown in FIG. 6, after detecting the reference crank angle, the binary value of the cam angle signal of BTDC 10 ° in the α region, that is, the presence or absence of the BTDC 10 ° signal, and the cam angle signal of BTDC 160 ° (ATDC 20 °) in the β region. Are determined, that is, the presence or absence of a signal, and cylinder discrimination is performed using these combination patterns. Referring to FIG. 5, when both the BTDC 10 ° signal and the BTDC 160 ° signal are detected, it is determined that the third cylinder is in the compression stroke. Thus, the cylinder is specified from the relationship of the binary information of the cam angle sensor signal in the α region and the β region.

  Next, with reference to FIG. 7, a description will be given of a response when the crank angle sensor 18 is normal but the cam angle sensor 29 is abnormal. In this case, since it is impossible to specify the cylinder only by the crank angle sensor signal information, the cylinder group or group discrimination is performed.

  As can be seen from FIG. 3 and FIG. 4, the crank angle signal installed on the crankshaft signal plate 18 a has different unequal intervals at every 180 °, as described above, the 30 ° interval from BTDC60 to BTDC30, There are two unequally spaced portions at 40 ° intervals from BTDC70 to BTDC30 °. Here, an unequal interval portion is provided every 180 ° which is a number obtained by dividing 720 ° which is an angle of two rotations of the 4-cycle engine by four cylinders.

  The cylinder group and the group are discriminated by identifying the unequal intervals provided in this way. In this example, the signal interval time (time interval) of the crank angle sensor is set every time the crank angle sensor signal is detected. Measure and compare the time interval CRT2 of the previous crank angle sensor signal and the time interval CRT1 between the current crank angle sensor signal. Then, when CRT2 × coefficient (for example, 2) <CTR1 is satisfied, it is determined that the intervals are unequal, and in other cases, it is determined that the intervals are equal. The number of equally spaced signals up to the BTDC 30 ° signal (generated signal A) that is the reference crank angle is counted CNTR.

  In addition, since there are two types of unequal intervals, 30 ° and 40 °, it can be determined by the difference in the number of detections. In the example showing the operation state shown in FIG. 7, when the reference crank angle signal is detected, the number of equally spaced signals is reset and sequentially counted up until unequal intervals are detected. The counter is 14 when measurement is performed until an unequal interval of 40 ° is detected. On the other hand, when the measurement is performed until the unequal interval 30 ° is detected, the counter is 15. Thus, when the count number changes from 14 to 0, it is determined that the compression BTDC of the third cylinder or the second cylinder is 30 °, and the group can be determined.

  Next, a cylinder discrimination method by the cam angle sensor 29 when the crank angle sensor 18 is abnormal will be described. When the crank angle sensor is normal, as described above, the generation position of the signal position of the cam angle sensor is identified by the crank angle signal (region α or β), and cylinder discrimination is performed. This determination method cannot be used. Therefore, cylinder discrimination is performed using the cam angle signal arrangement shown in FIG. 8 and the bit pattern shown in FIG.

  FIG. 8 is an example of the arrangement of cam angle signals. For the cam angle signal, cylinder discrimination signals that are used when the crank angle sensor is normal are provided in the regions α and β. However, when the crank angle sensor is abnormal, the cam angle signals for cylinder discrimination installed in the regions α and β have no meaning. This is because it is very difficult to execute control of the fuel injection timing and the ignition timing after the cylinder discrimination even if the cylinder discrimination is performed only by the signals in the α and β regions. As shown in FIG. 6, it can be determined that the first cylinder is in the compression stroke when there is no signal in the α region and the β region, but the α and β regions cannot be specified because there is no information on the crank angle. . Therefore, it cannot be determined when the stroke of the first cylinder is reached. Even if it can be determined, there is no appropriate cam signal information for setting the ignition timing, so knocking due to over-advanced angle due to improper ignition timing or catalyst overheating due to over-retarding angle is induced, leading to engine damage Probability is high.

  Therefore, in this example, this problem is solved by providing a reference signal for fuel injection control and ignition control in the region γ of each cylinder described above. Specifically, as shown in FIG. 8, the reference signal for fuel injection control is set at BTDC 100 ° CA for each cylinder, and the reference signal for ignition timing is set at BTDC 70 ° CA for each cylinder. As a result, in this example, 12 signals are arranged on the cam shaft signal plate 29a. The cylinder discrimination by the cam angle signal is performed by measuring the cam angle signal interval (time interval) and using the ratio information as follows.

  The time interval CAMT2 (points A and B in FIG. 8) of the previous cam angle sensor signal is compared with the time interval CAMT1 (points B and C in FIG. 8) between the current cam angle sensor signals. To decide. For example, “CAMT2 × K (K: coefficient = 0.5)> CAMT1 is satisfied,“ short ”is set,“ non-established ”is“ long ”,“ short = 1 ”, and“ length = 0 ”. Eight pieces of information “1” and “0” are taken in succession, and cylinder determination is performed based on the relationship as shown in FIG. Specifically, when information of 8 consecutive bits from the BTDC 70 ° signal of the # 2 cylinder which is No. 12 to the BTDC 10 ° signal of the third cylinder is used, “10101010” (170 in decimal) is obtained. These eight bit sequences are all different from the other 11 patterns. Therefore, the arrangement of “10101010” can be specified as the compression stroke BTDC 10 ° of the third cylinder. By installing the cam angle signal in this way, the cylinder determination can be made only by the signal of the cam angle sensor, and further, the fuel and ignition can be controlled with high accuracy.

  Although the above is an example of an in-line four-cylinder engine, the present invention can be applied to various engines such as a horizontally opposed engine and a V-type engine. Examples thereof are shown in FIGS.

  FIGS. 10 and 11 show application examples to a horizontally opposed four-cylinder engine, and FIGS. 12 and 13 show application examples to a V-type six-cylinder engine.

  The crank angle sensor signal, cam angle signal, and stroke of each cylinder in two rotations of the horizontally opposed four-cylinder engine have the relationship shown in FIG. Cam angle signals are installed on the intake side of the right and left banks.

  In the crank angle, the same crank angle signal as that of the in-line four-cylinder engine is installed. There are an equally spaced portion with a crank angle of 10 ° and an unequally spaced portion (tooth missing portion) with a signal interval of 30 ° or 40 °. As described above with reference to FIG. 5, the unequal interval portion is provided with two types of crank angle signals CR, BTDC 60-30 ° and BTDC 70-30 °, starting from BTDC 30 °. The BTDC 30 ° is a reference crank angle (generated signal). It corresponds to A). Then, as shown in FIG. 11, the cylinder can be specified by the relationship between the CAM (cam angle) signals of the left and right banks and the unequal interval portions (tooth missing portions) of the crank angle signals. If the right bank cam sensor is abnormal, the third cylinder of the compression stroke can be recognized by detecting the BTDC165 ° signal after detecting the unequal interval 30 ° interval (BTDC60 to BTDC30) of the crank angle signal. Similarly, when the left bank cam sensor is abnormal, if the BTDC 165 ° signal is detected after detecting the unequal interval 30 ° interval (BTDC 60 to BTDC 30) of the crank angle signal, the fourth cylinder of the compression stroke can be recognized. When both cam angle sensors fail, it can be dealt with by the same method using the crank angle signal as described above with reference to FIG.

  Further, even if the crank angle sensor is abnormal, the cylinder can be specified by the combination of the left and right cam signals. Specifically, as in FIG. 8, the time interval CAMT2 of the previous cam angle sensor signal is compared with the time interval CAMT1 between the cam angle sensor signals of this time, and CAMT2 × K (K: coefficient = 1. 5) When “CAMT1” is satisfied, “short = 1” is set. In this case, in the case of the right bank, it is “1” only when compression # 4 BTDC165 to compression # 1 BTDC15 ° (crank angle interval 330 °) and compression # 1 BTDC15 to compression # 3 BTDC15 ° (crank angle interval 180 °). The third cylinder compression stroke BTDC 15 ° signal can be recognized. As a result, cylinder discrimination is completed, and the BTDC 15 ° signal installed in each cylinder of each bank is used as the ignition timing (ignition timing fixed), so that an extreme decrease in engine torque can be prevented.

  The crank angle sensor signal, the cam angle signal, and the strokes in two rotations in the V-type 6-cylinder engine have the relationship shown in FIG. Cam angle signals are installed on the intake side of the right and left banks. As in the above-described four-cylinder engine, the crank angle includes an equally spaced portion with a crank angle of 10 ° and an unevenly spaced portion (tooth missing portion) with a signal interval of 30 ° or 40 °. This non-uniformly spaced portion starts from BTDC 50 °, which is different from that of the four cylinders, and has three types of crank angle signals CR of BTDC 100-50 °, BTDC 90-50 °, BTDC 80-50 °, and this BTDC 50 ° is the reference crank angle. Corresponds to (generated signal A). Similarly to FIG. 8 described above, with respect to the cylinder determination regions α and β with respect to the reference crank angle signal, there are three inaccuracies of the BTDC 35 ° signal, the BTDC 5 ° signal, and the crank angle signal installed in the CAM (cam angle) of the left and right banks. As shown in FIG. 13, the cylinder can be specified from the relationship between the equally spaced portions (tooth missing portions).

  If the cam sensor abnormality in the right bank is detected, compression is performed by detecting a BTDC 35 ° signal in the cylinder determination region α and a BTDC 5 ° signal in the region β after detecting an unequal interval 40 ° interval (BTDC90 to BTDC50) of the crank angle signal. If it can be recognized as the stroke No. 3 cylinder and then the crank angle unequal interval 30 ° interval (BTDC80 to BTDC50) is detected, it can be identified as BTDC 50 ° of the compression stroke No. 3 cylinder. Similarly, in the case of a cam sensor abnormality in the left bank, similarly, when the BTDC 35 ° signal and the BTDC 5 ° signal are detected after detecting the unequal interval 40 ° interval (BTDC90 to BTDC50) of the crank angle signal, the compression stroke No. 6 is detected. If it can be recognized as a cylinder and then a crank angle unequal interval of 30 ° (BTDC 80 to BTDC 50) is detected, it can be specified as BTDC 50 ° of the compression stroke No. 6 cylinder.

  If both cam angle sensors fail, as in FIG. 7, the information on the number of signals at unequal intervals of the crank angle signal is used to indicate # 3 and # 6, # 1 and # 4, # 2 and # 5. Grouping is possible.

  Further, even if the crank angle sensor is abnormal, the cylinder can be specified by the combination of the left and right cam signals. Specifically, as in FIG. 8, the time interval CAMT2 of the previous cam angle sensor signal is compared with the time interval CAMT1 between the current cam angle sensor signals, and CAMT2 × K (K: coefficient = 0. 5) When “CAMT1” is satisfied, “short = 1” is set. In this case, in the case of the right bank, “1” only when compression # 3 BTDC35 to compression # 1 BTDC 35 ° (crank angle interval 240 °) and compression # 1 BTDC35 to compression # 1 BTDC 5 ° (crank angle interval 30 °). Thus, the first cylinder compression stroke BTDC 5 ° signal can be recognized. This completes cylinder discrimination.

  Next, processing executed when the control unit 100 performs the cylinder determination as described above will be described with reference to the flowcharts of FIGS. 14, 15, and 16.

  FIG. 14 is a routine executed when the crank angle sensor and the cam angle sensor are normal. In step 101, the crank angle sensor signal is read, and the CRT1 and CRT2 between the current and previous (one time before) crank angle sensor signals are measured. In step 103, the unequal intervals are determined, and a BTDC 30 ° signal that is a reference crank angle is determined. If it is determined that the signal is a BTDC 30 ° signal, in step 104, it is determined that the cylinder determination first half region α, and the cam angle signal is read.

  If the cam angle signal is input before the end of the cylinder determination first half region α, the process proceeds to step 105, where the BTDC 10 ° signal is input, and the flag 10 indicating the cam signal input state in the α region is set to 1. On the other hand, the flag 10 is 0 when no signal is input. When the cylinder determination first half area α is completed, the process proceeds to a cylinder determination second half area β in step 108. If the cam angle signal is input before the end of the cylinder determination first half region β, the routine proceeds to step 109, where the BTDC 160 ° signal is input, and therefore the flag 160 indicating the cam signal input state in the β region is set to 1. On the other hand, if no signal is input, the flag 160 is set to 0 in step 111. Then, in step 112, the cylinder determination is executed based on the matrix shown in FIG. 6 based on the results of the flag 10 and the flag 160, and this flow is finished.

  FIGS. 15 and 16 are flowcharts of specific examples in the case where the cylinder is determined only by the cam angle signal when the crank angle sensor signal is abnormal. FIG. 15 shows an example of the bit pattern recognition method in step 301 of FIG. In step 201, a cam angle signal is input. In step 202, the previous bit information is bit-shifted and replaced with Bit 1 so that the latest time interval determination result can be input to the position of Bit 0. In step 203, it is determined whether or not the above-mentioned CAMT2 × K (K: coefficient = 0.5)> CAMT1 is established as the latest cam angle signal is input. If “1” is not established, “length = 0” is processed in step 205, and the processing in step 301 is terminated.

  Step 302 is a process of determining which of all 12 patterns shown in FIG. 9 is established. In this example, it is determined whether or not the bit pattern “10101010” indicating the compression stroke BTDC 10 ° CA signal of the third cylinder shown in FIG. 8 is established. If not, the cylinder determination is not completed in step 305. On the other hand, if established, it is determined in step 303 that the compression stroke of the third cylinder is BTDC 10 ° CA, and in step 304, the cylinder determination and crank angle determination completion processing is performed.

  In this example, the description has been made using one bit pattern, but there is a method of whether or not all 12 patterns correspond to somewhere in the processing of step 302.

  FIG. 17 shows an example of a flowchart in the case where the cylinder group is determined only by the crank angle signal when the cam angle sensor is abnormal. In step 401, the signal of the crank angle sensor is read, and CRT1 and CRT2 between the current and previous (one time before) crank angle sensor signals are measured. In step 402, an unequal interval portion is determined, and a BTDC 30 ° signal that is a reference crank angle is determined.

  If it is not determined that the signal is a BTDC 30 ° signal, the crank angle signal input number counter CNTR is incremented in step 404. On the other hand, if it is determined that the signal is a BTDC 30 ° signal, the crank angle signal input number counter CNTR is cleared to 0 in step 403. In step 405, it is determined whether or not the crank angle signal input number counter CNTR = 15. When CNTR = 15, the cylinder GrA (the compression stroke of the first cylinder or the fourth cylinder) can be determined at step 406.

  As described above, even if either the cam angle sensor or the cam angle sensor is abnormal, it is possible to determine the cylinder and the cylinder group, and it is possible to perform the same control for fuel and ignition as normal. Become.

  As mentioned above, although one Embodiment of this invention was explained in full detail, this invention is not limited to above-described embodiment, It designs, without deviating from the mind of this invention described in the claim. In addition, various changes can be made.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which applied one Embodiment of the cylinder determination apparatus which concerns on this invention to the vehicle-mounted in-line 4 cylinder engine. The internal block diagram of a control unit. The figure which shows the relationship of the stroke of a crank angle sensor signal and a cam angle signal, and a crank in-line 4 cylinder engine in 2 engine rotations. Specific examples of cam angle plate shape and crank angle plate shape (example of inline 4-cylinder). The figure which shows an example of the positional relationship of the crank angle signal and cam angle signal for cylinder determination (example of inline 4 cylinder). The figure which shows the cylinder discrimination | determination using the cam angle signal in the area | region (alpha) and the area | region (beta) (example of inline 4 cylinder). The figure which shows the operation state at the time of performing cylinder determination at the time of cam angle sensor (signal) abnormality (example of inline 4 cylinder). The figure which shows the operation state at the time of performing cylinder determination at the time of crank angle sensor (signal) abnormality (example of inline 4 cylinder). The figure which shows the relationship between the bit pattern at the time of cylinder determination at the time of crank angle sensor (signal) abnormality, and the reference position of each cylinder (example of in-line 4 cylinders). The figure which shows the relationship between a cam angle signal, a crank angle signal, and the stroke of each cylinder (example of 4 cylinders horizontally opposed). The figure which shows the cylinder determination by a cam angle signal and a crank angle signal (example of 4 cylinders horizontally opposed). The figure which shows the relationship between a cam angle signal, a crank angle signal, and the stroke of each cylinder (example of V type 6 cylinder). The figure which shows the cylinder determination by a cam angle sensor and a crank angle sensor (example of V type 6 cylinder). The flowchart which shows the example of one routine performed when a control unit performs cylinder determination when a crank angle sensor and a cam angle sensor are normal. The flowchart which shows the example of one routine which produces | generates the Bit information which a control unit performs when a crank angle sensor is abnormal. The flowchart which shows the example of one routine of Bit pattern recognition which a control unit performs when a crank angle sensor is abnormal. The flowchart which shows the example of one routine performed when a cylinder group determination is only based on a crank angle signal when the cam angle sensor is abnormal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine # 1- # 6 ... Cylinder number 10 ... Cylinder determination apparatus 16 ... Spark plug 18 ... Crank angle sensor 18a ... Signal plate 29 ... Cam angle sensor 29a ..Signal plate 100 ... Control unit

Claims (6)

One or a plurality of crank angle sensors comprising a crank signal plate that is rotated integrally with the crankshaft of the engine and a detector disposed in the vicinity of the outer periphery of the crank signal plate, and the camshaft of the engine is rotated integrally. A cam signal plate to be clamped and one or a plurality of cam angle sensors comprising detectors arranged close to the outer periphery of the cam signal plate, and based on the signals obtained from the crank angle sensor and the cam angle sensor An engine cylinder determination device comprising a control means for performing cylinder determination,
On the outer periphery of the crank signal plate,
A plurality of detected parts composed of teeth, protrusions, concave parts, convex parts, holes, etc., are arranged at equal angular intervals over a predetermined angular range; and
At least two types of unequal intervals that are larger in angular interval than the equally spaced portions and differ in size, the unequal spaced portions being installed by the number obtained by dividing 720 ° by the number of cylinders, and The generation signal A corresponding to the unequal intervals has unequal intervals arranged to be generated at the same crank angle position in the same stroke,
On the outer periphery of the cam signal plate, a plurality of detected parts consisting of teeth, protrusions, concave parts, convex parts, holes, etc. are installed,
The cam signal plate is divided into the same number of areas as the number of cylinders,
Each area is divided into at least three regions α, β, γ,
In each of the regions α, β, and γ, a detected portion is installed at a predetermined angular position,
The detected portions installed in the region α and the region β are set so that all combinations of binarized bit information generated by the detected portions are different for each cylinder. Cylinder determination device. In the engine cylinder determination device according to claim 1,
An engine cylinder determination device characterized in that at least two detected parts are provided in the region γ provided on a cam signal plate. The engine cylinder determination device according to claim 1 or 2,
When the crank angle sensor and the cam angle sensor are normal, after detecting the generated signal A detected by the crank angle sensor, the combined result of the detected portion of the region α and the region β of the cam signal plate A cylinder determining apparatus for an engine, which performs cylinder determination in response. The engine cylinder determination device according to claim 1 or 2,
An engine cylinder determination device characterized in that, when the crank angle sensor is abnormal and the cam angle sensor is normal, cylinder determination is performed in accordance with an arrangement of detected portions installed on the cam signal plate. In the engine cylinder determination device according to claim 1 or 2,
When the crank angle sensor is normal and the cam angle sensor is abnormal, the cylinder group is determined by discriminating two types of unequal intervals according to the number of detected equal intervals installed on the crank signal plate. An engine cylinder determination device characterized by: The engine cylinder determination device according to claim 2,
When the crank angle sensor is abnormal and the cam angle sensor is normal, the fuel injection timing and the ignition energization start timing are set based on the cam angle signal of the region γ provided on the cam signal plate. A cylinder determining device for an engine characterized by the above.

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