JP4321449B2 - Cylinder determination device for internal combustion engine - Google Patents

Description

  The present invention relates to a cylinder determination device for identifying which cylinder in a rotating engine is in a specific stroke, and is also applicable to a three-cylinder and a four-cylinder internal combustion engine with a variable valve timing mechanism. The present invention relates to a possible cylinder determination device.

  In an internal combustion engine, one cycle of operation is composed of, for example, a plurality of strokes of 2 or 4. For this reason, in a multi-cylinder internal combustion engine having two or more cylinders, in order to control ignition timing, fuel injection timing, etc. It is necessary to identify whether the cylinder is in a specific stroke, for example, the compression stroke. For this reason, cylinder determination is required.

  By the way, in such a cylinder determination device, as a first conventional example, a rotation detection disk mounted on a camshaft is provided with a different number of protrusions for determining the crank angle of each cylinder, and this protrusion is provided for each cylinder. Detect with cam angle sensor. There is a method of determining a specific bit state from the time ratio of the pulse interval of the detected signal, and determining a predetermined crank angle of a predetermined cylinder when the arrangement of the bit state becomes a predetermined arrangement pattern. (For example, refer to Patent Document 1). As another example of using a cam sensor, there is an example in which a cylinder is discriminated using a signal plate or the like attached to a rotating part (for example, see Patent Documents 2 to 5).

  Further, as a second conventional example, a crank angle determination protrusion is provided on a signal plate mounted on a crankshaft, the crank angle is detected by a crank angle sensor, and a cylinder determination is performed on a signal plate mounted on a camshaft. The cylinder position of the cylinder in a predetermined stroke state is detected by providing a protrusion, and the cylinder position of the cylinder in the predetermined stroke state is determined by the relationship between the crank angle detected by the crank angle sensor and the cylinder position detected by the cam angle sensor. There is a method for detecting a predetermined crank position. In the second conventional example, the cylinder can be determined if the phase shift between the crank angle and the cam angle is within a predetermined angle. Therefore, the second conventional example can also be applied to an engine having a variable valve timing mechanism for controlling the phase of the crank angle and the cam angle. In this case, the signal detected by the cam angle sensor is variable valve timing control. Is used as a cam angle detection signal (see, for example, Patent Document 6). In addition, there is an example of cylinder determination that can be applied to variable valve timing control by mounting a crank angle sensor and a cam angle sensor (see, for example, Patent Documents 7 to 9).

JP 11-311147 A Japanese Patent Application Laid-Open No. 2000-297685 JP 2000-104618 A JP 2003-74405 A JP 2004-60450 A JP 2000-18083 A JP 2000-18083 A Japanese Patent Laid-Open No. 7-150989 JP 2000-297686 A

  In the first conventional example, a rotation detection disc mounted on a camshaft is provided with a projection for determining a crank angle for each cylinder. This projection is detected by a cam angle sensor, and the detected signal is output to each cylinder. As a reference signal for fuel and ignition control, the engine control device controls the timing of the fuel injection position and the ignition position. Therefore, since the rotation detection and crank angle determination disk mounted on the camshaft needs to have a reference signal for each cylinder, the position of the protrusion is dependent on the number of engine cylinders and is dedicated to the number of engine cylinders. Therefore, it is necessary to design a disc for detecting the rotation and determining the crank angle.

  In the second conventional example, the signal plate mounted on the crankshaft has a crank angle determination projection for each cylinder. After the cylinder determination is completed, the crank angle determination projection is detected by a crank angle sensor. The engine control device controls the timing of the fuel injection position and the ignition position using the obtained signal as a reference signal for fuel and ignition control for each cylinder. Therefore, since the signal plate to be mounted on the crankshaft needs to have a reference signal for each cylinder, the position of the protrusion is dependent on the number of engine cylinders, and the signal plate to be mounted on the crankshaft according to the number of engine cylinders. Need to design.

  On the other hand, a signal obtained by detecting the protrusion of the signal plate attached to the camshaft by the cam angle sensor is used as a cam angle detection signal for variable valve timing control. Are controlled so as to be the target phase. In the second conventional example, the reference crank angle for variable valve timing control uses a crank angle determination protrusion provided for each cylinder of the signal plate mounted on the crankshaft. Therefore, it is necessary to install a projection of a signal plate attached to the camshaft so as to generate a cam angle detection signal for variable valve timing control so as to correspond to a reference crank angle corresponding to each cylinder. Accordingly, the position of the projection of the signal plate attached to the camshaft is dependent on the number of engine cylinders, and it is necessary to design the signal plate attached to the camshaft according to the number of engine cylinders.

  As shown in the first conventional example and the second conventional example, in the conventional cylinder determination device for an internal combustion engine, the disc or signal plate mounted on the camshaft and the crankshaft needs to be designed according to the number of engine cylinders. However, between engines with different numbers of cylinders, the disc or signal plate to be mounted on the camshaft and crankshaft has not been made completely common.

  An object of the present invention is to make the signal plate mounted on the camshaft and crankshaft for, for example, 3 cylinders and 4 cylinders completely the same, which is advantageous in terms of cost, and is provided with a variable valve timing mechanism. It is an object of the present invention to provide a cylinder determination device for an internal combustion engine that can be applied to both.

  The object includes a cam signal plate attached to the camshaft, a crank signal plate attached to the crankshaft, and a cam angle sensor and a crank angle sensor disposed to face the cam signal plate and the crank signal plate, respectively. The cam signal plate includes three concave group or convex group, and the number of concave parts or convex parts of the concave group or convex group is different from the number of the other concave group or convex group, respectively. Position at which the angular interval between one recess or projection in a group or projection group and one recess or projection in an adjacent recess group or projection group is a multiple of 90 ° in cam angle A concave group or a convex group, and one concave or convex part in the concave group or convex group, and another concave or convex part in the adjacent concave group or convex group. The angle interval is 12 cam angles A concave group or a convex group is arranged at a position that is a multiple of 0 °, and the crank signal plate has concave parts or convex parts that are unequally spaced at a predetermined crank angle and equally spaced at other crank angles. The unequal interval is provided at two positions opposite to each other at a crank angle of 180 °, the signal based on the unequal interval portion is detected by the crank angle sensor, and the signal based on the cam signal plate is A cylinder determination device for an internal combustion engine, wherein the cylinder determination is performed using a signal based on the unequal interval portion and a signal based on the cam signal plate.

  By configuring the engine cylinder determination device as described above, the cam signal plate and the crank signal plate can be made completely common in the three-cylinder and four-cylinder engines, which is very advantageous in terms of cost and has a variable valve timing mechanism. It is possible to provide a cylinder determination device for an internal combustion engine that can be applied to both a cylinder and a four-cylinder internal combustion engine.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an engine cylinder determination device according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows the overall configuration of an engine system in which the cylinder determination device of this embodiment is provided. In FIG. 1, an engine 1 includes a cylinder 1a and a piston 1b. An intake pipe (intake branch pipe) 4 and an exhaust pipe 19 are connected to an upper portion of the cylinder 1a, and an intake valve 7 and an exhaust pipe are connected. A valve 8, an electronically controlled fuel injection valve 6, and a spark plug 18 are provided.

An air cleaner 5 and a throttle body 2 having a throttle valve for controlling the amount of intake air are arranged upstream of the intake pipe 4. The throttle body 2 is provided with an ISC valve 21, a throttle sensor 17 and a pressure sensor 16, and an exhaust pipe 19 is provided with an O ₂ sensor 11.

  The engine 1 includes a water temperature sensor 12, a crank angle sensor 13 that receives a signal from a crank signal plate 51 attached to the crankshaft 60, and a cam angle sensor 14 that receives a signal from a cam signal plate 15 attached to an intake camshaft 62. Has been deployed.

  The fuel from the fuel tank 30 is supplied to the fuel injection valve 6 by the fuel pump 31, but the pressure is adjusted by the regulator 32 and reaches the fuel injection valve 6 through the fuel pipe 33. It is injected with the injection amount.

  A variable valve timing mechanism 41 is installed on the intake camshaft 62. The variable valve timing mechanism 41 performs advance angle control by the hydraulic pressure controlled by the variable valve timing drive circuit 40. The variable valve timing drive circuit 40 controls the hydraulic pressure applied to the variable valve timing mechanism 41 based on a signal from the engine control device (controller) 10.

The controller 10 inputs detection signals from the throttle sensor 17, pressure sensor 16, O ₂ sensor 11, water temperature sensor 12, crank angle sensor 13, cam angle sensor 14, etc., as well as the fuel injection valve 6, ISC valve 21, ignition Output signals are transmitted to the spark plug 18 and the fuel pump 31 via the coil 9. 22 is a battery, 23 is a main relay for the controller 10, and 24 is a fuel pump relay. As shown in FIG. 3, the crank angle sensor 13 and the cam angle sensor 14 capture the change α of the magnetic field that occurs every time the projections provided on the crank signal plate 51 and the cam signal plate 15 pass, and the internal processing circuit β is generated and sent to the controller 10.

FIG. 2 shows an internal configuration of the control device (controller) 10. The control device (controller) 10 includes an input circuit 191, an A / D changing unit 192, a central processing unit 193, and the like.
The computer includes a ROM 194, a RAM 195, and an output circuit 196. In the case of an analog signal, the input circuit 191 receives, for example, signals from the water temperature sensor 12, the throttle opening sensor 17, etc., removes noise components from the signals, and sends the signals to the A / D converter 192. It is for output.

  The central processing unit 193 takes in the A / D conversion result, and executes the fuel injection control program stored in the medium such as the ROM 194 or a predetermined control program for other control, thereby performing the control and diagnosis. It has a function to execute. 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 output signal 197 through the output circuit 196, and the fuel injection valve 6, ignition coil 9, variable Used for controlling the valve timing drive circuit 40 and the like. On the other hand, the signals from the crank angle sensor 13 and the cam angle sensor 14 are sent to the central processing unit 193 through signal lines 198 and 199 as high / low signals after the presence or absence of signals is identified by the input circuit 191. In the central processing unit 193, when the voltage level of the signal line 198 changes from Low to High, an interrupt process is performed at the timing indicated by γ in FIG.

  FIG. 4 shows an example of the mounting state of the crank angle sensor 13 and the crank signal plate 51 and the cam angle sensor 14 and the cam signal plate 15 of the present embodiment to the engine 1.

The vertical movement of the piston 1 b provided in the engine 1 is converted into a rotational movement by the crankshaft 60, and a transmission composed of a crank pulley 69 mounted on the crankshaft 60, a timing belt 68, an intake cam pulley 64, and an exhaust cam pulley 67. The mechanism 70 drives the intake camshaft 62 and the exhaust camshaft 65 at half the rotational speed of the crankshaft 60, and the intake cam 63 provided on the intake camshaft 62 opens and closes the intake valve 7, The exhaust valve 8 is opened and closed by an exhaust cam 66 provided on the exhaust cam shaft 65.

A crank signal plate 51 is attached to the crankshaft 60, and a crank angle sensor 13 is disposed at a position facing the crank signal plate 51. A cam signal plate 15 is mounted on the intake cam shaft 62, and a cam angle sensor 14 is disposed at a position facing the cam signal plate 15.

  A variable valve timing mechanism 41 is installed on the intake camshaft 62 to control the advance angle of the intake camshaft 62.

The crank signal plate 51 mounted on the crankshaft 60 is, as shown in FIG.
There are toothless portions of 30 ° CA that are signals of unequal intervals at two opposite positions of 180 ° CA, and the other signals are signals of equal intervals every 10 ° CA. The crank angle sensor 13 is disposed at a position facing the crank signal plate 51, and the crank angle sensor 13 detects a change in the magnetic field when the crank signal plate 51 mounted on the crankshaft 60 rotates. It has become.

  As shown in FIG. 6, the cam signal plate 15 attached to the cam shaft 62 has a signal group 15a, a signal group 15b, and a signal group 15c. The signal group 15a has one signal, the signal group 15b has three signals, and the signal group 15c has two signals. Each signal group has a different signal number from the other signal groups. It is configured.

  Each signal position of the cam signal plate 15 will be specifically described. The signal 15ca of the signal group 15c is disposed at a cam angle of 120 ° (corresponding to a crank angle of 240 ° (hereinafter, the crank angle is represented by “° CA”)) with respect to the signal of the signal group 15a, and the signal 15cb Is disposed at a cam angle of 90 ° (180 ° CA). Further, with respect to the signal group 15a, the signal 15ba of the signal group 15b is arranged at a cam angle of 120 ° (120 ° CA), and the signal 15bc is arranged at a cam angle of 180 ° (360 ° CA). The signal 15bb of the signal group 15b is disposed between the signal 15ba and the signal 15bc with a cam angle of 30 ° (60 ° CA).

The cam angle sensor 14 is disposed at a position facing the cam signal plate 15, and the cam angle sensor 14 detects a change in the magnetic field when the cam signal plate 15 mounted on the cam shaft 62 rotates. It has become.

  FIG. 7 shows the stroke of each cylinder, the crank signal that is the output signal of the crank angle sensor 13, and the output of the cam angle sensor 14 when the cylinder determining device of the engine of the present embodiment is adopted in the engine 1, for example, 4 cylinders or 3 cylinders. The relationship with the cam signal which is a signal is shown.

The crank signal from the crank angle sensor 13 has a toothed portion where the crank signal plate 51 becomes a signal of unequal intervals (30 ° CA) at positions of every 180 ° CA, and other signals are equally spaced (10 ° CA). On the other hand, the cam signal from the cam angle sensor 14 is output according to three signal groups 15a, 15b, 15c installed on the cam signal plate 15.

  The position of the crank signal from the crank angle sensor 13 and the cam signal from the cam angle sensor 14 is such that the cam signal plate 51 has a cam signal plate 51 at a position of every 180 ° CA. The three signal groups 15a, 15b, and 15c of 15 are configured to be positioned between the tooth cut portions of the crank signal plate 51 as shown in FIG.

In the case of a four-cylinder engine, the cam signal plate 15 signals that the cam angle signal 15bc is at an angle A on the advance side with respect to the first cylinder (# 1) compression stroke top dead center (TDC) of the four-cylinder engine. Install to generate. Since the cam signal 15cb is at the position of 180 ° CA on the retard side with respect to the cam signal 15bc, a signal is generated at the position of the angle A on the advance side with respect to the third cylinder (# 3) TDC of the four-cylinder engine. To do. Similarly, the signal of the cam signal group 15a is generated at a position of an angle A on the advance side with respect to the fourth cylinder (# 4) TDC of the four-cylinder engine.

  Since the cam signals 15bc and 15cb and the signal of the cam signal group 15a are generated with the same angle difference A with respect to the TDCs of # 1, # 3, and # 4 of the 4-cylinder engine, the variable valve timing of the 4-cylinder engine. Ideal for cam angle detection signal in control.

  In the case of a three-cylinder engine, the cam signal plate 15 is installed so that the cam signal 15ba generates a signal at an angle B position on the advance side with respect to # 1 TDC of the three-cylinder engine. Since the cam signal 15ca is at a position of 240 ° CA on the retard side with respect to the cam signal 15ba, a signal is generated at a position of an angle B on the advance side with respect to # 3TDC of the 3-cylinder engine. Similarly, the signal of the cam signal group 15a is generated at a position of angle B on the advance side with respect to # 2TDC of the three-cylinder engine.

  Since the cam signals 15ba and 15ca and the signal of the cam signal group 15a are generated with the same angle difference B with respect to the TDCs of # 1, # 3, and # 2 of the three-cylinder engine, the variable valve timing of the three-cylinder engine. Ideal for cam angle detection signal in control.

  FIG. 8 shows the concept of cylinder determination in the engine cylinder determination apparatus of the present embodiment.

  As described above with reference to FIG. 7, the position configuration of the crank signal from the crank angle sensor 13 and the cam signal from the cam angle sensor 14 is such that the crank signal plate 51 is located at a position of every 180 ° CA. The three signal groups 15a, 15b, and 15c of the cam signal plate 15 are positioned between the toothed portions of the crank signal plate 51 with respect to the portion. By configuring the crank signal and the cam signal as described above, the number of cam signals input by the cam signal group is measured with the interval between the tooth-less portions of the continuous crank signal plate 51 as a cam signal number measurement section. In an engine that does not have a variable valve timing mechanism, cylinder determination can be performed based on the measured number of cam signals. However, in an engine having a variable valve timing mechanism, cylinder determination must be performed without erroneous determination even when the cam position is at the most retarded angle and most advanced angle.

  In the engine cylinder determination device of the present embodiment, as shown in FIG. 8, when the cam position is the most retarded angle, the cam signal groups 15a, 15b, and 15c are located between the tooth missing portions. However, when the cam position is the most advanced angle, the signal 15ba of the cam signal group 15b straddles the adjacent cam signal number measurement section in which the advanced angle side continues. For this reason, in the cam signal number measurement section of one section, the number of cam signals of the cam signal 15ba and the cam signal group 15a is both 1 count, so it is impossible to distinguish which cam signal. Similarly, the signals other than the cam signal 15ba in the cam signal group 15b and the cam signal group 15c are both counted in the cam signal number measurement section in one section, so that it is easy to distinguish which cam signal. Absent. If the cylinder determination is performed in the cam signal number measurement section in one section, there is a problem as described above. Therefore, in the cylinder determination device for the engine of this embodiment, the cam signal count in two consecutive cam signal count measurements is set. The cylinder is determined based on the combination. The configuration of the cylinder determination is the same for the 3-cylinder engine and the 4-cylinder engine. As a result, cylinder determination can be performed without erroneous determination even in a three-cylinder and four-cylinder engine having a variable valve timing mechanism.

  FIG. 9 is a control block diagram for implementing the cylinder determination device of the present embodiment.

  The crank signal of the crank angle sensor 13 is input to the input processing means 210 to remove noise and the like. The cam signal of the cam angle sensor 14 is also removed from noise and the like by the input processing means 220. The inputted crank signal is converted into a tooth missing position detection signal by the tooth missing position detecting means 230, and the cam signal and the tooth missing position detecting signal are inputted to the cam signal counting means 240, and the tooth missing position detecting signal is inputted. Is input, the cam angle signal is counted until the next tooth missing position detection signal is input, and the count signal is continuously output.

  In the case of a four-cylinder engine, the count signal is continuously generated and output as 32103210. The patterned count signal generated in this way is output to the cam signal count number storage means 270, and the cam signal count number for two consecutive cam signal number measurements is stored. The stored cam signal counts for the two consecutive cam signal number measurements are output to the cylinder determining means 250 to perform cylinder determination. The cylinder determination is performed by taking out pattern data set in advance by the cylinder determination reference storage means 260 and comparing it with the number of count signals to check whether they match.

  FIG. 10 shows a tooth missing detection method of the tooth missing position detecting means 230.

The tooth missing position is located between the crank signal BTDC 105 ° CA signal and the BTDC 75 ° CA signal as shown in FIG. The tooth missing position is detected by comparing the time t2 between the crank signal BTDC 105 ° CA signal and the BTDC 75 ° CA signal and the time t3 and t1 between the crank signals before and after the tooth missing position. Specifically, the tooth missing position is determined under the AND condition of Expression 1 and Expression 2.

t2 / t1> A1 Formula 1
t2 / t3> A2 Formula 2
t1: Time between latest crank signals
t2: Time between previous crank signals
t3: Time between crank signals of the last time A1 and A2 take a value of about 2. In other words, when converted by the angle ratio, t1 is 10 °, t2 is 30 °, t3 is 10 °, t2 / t1 = t2 / t3 = 3, and if A1 and A2 are set to 2, detection of the tooth missing position is possible. Is possible.

  FIG. 11 shows the stroke of each cylinder, the crank signal, the cam signal, the missing tooth detection position, and the cam signal count between the missing tooth positions when the cylinder determining device of the engine of this embodiment is adopted in the four-cylinder and three-cylinder engine 1. It shows the relationship between numbers.

  The cam signal count signal that is input between the tooth missing detection positions detected by the above-described method is continuously generated and output as 32103210... When the cam position is in the most retarded state. In the most advanced angle state, 2212211... Are continuously generated and output. Further, the cylinder determination section is a continuous cam signal number measurement two section, which is 360 ° CA in terms of a crank angle.

  FIG. 12 shows the cylinder determination criteria in the case of a four-cylinder engine.

  As shown in FIG. 12, when the previous cam signal count is 3 or 2 and the current cam signal count is 2, the compression process of # 3, the previous cam signal count is 2 and the current cam signal count When the number is 1, the compression stroke of # 4, when the previous cam signal count is 1 and the current cam signal count is 0 or 1, the compression stroke of # 2, the previous cam signal count is 0 or 1 If the current cam signal count is 3 or 2, it is determined that the compression stroke is # 1.

  FIG. 13 shows the cylinder criteria for a three-cylinder engine.

  As shown in FIG. 13, when the previous cam signal count is 3 or 2 and the current cam signal count is 2, the compression process of # 3, the previous cam signal count is 2 and the current cam signal count If the number is 1, # 2 intake stroke, if the previous cam signal count number is 1 and the current cam signal count value is 0 or 1, # 2 compression stroke, the previous cam signal count number is 0 or 1 If the current cam signal count is 3 or 2, it is determined that the compression stroke is # 1.

  FIG. 14 shows an example in which variable valve timing mechanisms are mounted on both the intake cam and the exhaust cam.

The exhaust cam signal groups 15a ′, 15b ′, and 15c ′ include the intake cam signal groups 15a, 15b,
The signal shape is the same as that of the intake cam signal groups 15a, 15b, and 15c, and is arranged at a position having a 180 ° CA phase difference on the advance side with respect to the intake cam signal groups 15a, 15b, and 15c. The concept of cylinder determination uses a combination of signal counts of the exhaust cam signal and the intake cam signal instead of the combination of the previous and current cam signal counts. Since the cylinder determination can be performed by combining the intake cam signal count number and the exhaust cam signal count number in one section of the cam signal number measurement, the cylinder determination can be accelerated compared to the configuration of only the intake cam signal.

  Note that the crank signal detected by the crank angle sensor 13 can also be used as an engine misfire diagnosis signal in the controller 10.

1 is a system configuration diagram of an internal combustion engine embodying the present invention. It is an internal structure of the controller in this invention. It is a figure which shows the output characteristic of a crank angle sensor and a cam angle sensor. It is the figure which showed the mounting state to the engine of the crank angle sensor and cam angle sensor in this invention. It is a figure which shows the arrangement | positioning relationship between the crank angle sensor and crank signal plate in this invention. It is a figure which shows the arrangement | positioning relationship between the cam angle sensor and cam signal plate in this invention. It is a figure which shows the relationship of the stroke of each cylinder by this invention, a crank angle sensor detection position, and a cam angle sensor detection position. It is a figure which shows the idea of the cylinder determination in this invention. It is a control block diagram of the cylinder determination of the cylinder determination apparatus in this invention. It is a figure which shows the method of a tooth missing position detection in this invention. It is a figure which shows the relationship of the stroke of each cylinder by this invention, a crank angle sensor detection position, a cam angle sensor detection position, and a tooth missing detection position. It is a figure which shows the cylinder determination position based on the number of cam signals in the case of a 4-cylinder engine. It is a figure which shows the cylinder determination position based on the number of cam signals in the case of a 3-cylinder engine. It is a figure which shows the example of application of this invention in the engine equipped with the intake cam sensor and the exhaust cam sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Throttle body, 3 ... Collector, 4 ... Intake branch pipe, 5 ... Air cleaner, 6 ... Fuel injection valve, 7 ... Intake valve, 8 ... Exhaust valve, 9 ... Ignition coil, 10 ... Control device (controller) ), 13 ... Crank angle sensor, 14 ... Cam angle sensor, 15 ... Cam signal plate, 32 ... Fuel pressure regulating valve (pressure regulator), 51 ... Crank signal plate.

Claims (5)

A cam signal plate mounted on the camshaft, a crank signal plate mounted on the crankshaft, and a cam angle sensor and a crank angle sensor disposed opposite to the cam signal plate and the crank signal plate,
The cam signal plate includes three concave group or convex group, and the number of concave parts or convex parts of the concave group or convex group is different from the number of other concave group or convex group, respectively, The angle interval between one recess or projection in the recess group or projection group and one recess or projection in the adjacent recess group or projection group is a multiple of 90 ° in cam angle. A concave group or a convex group is disposed at a position, and one concave or convex part among the concave group or convex group, and another concave or convex part among adjacent concave groups or convex groups, and The concave group or the convex group is arranged at a position where the angular interval is a multiple of 120 ° in the cam angle,
The crank signal plate is provided with recesses or projections that are unequally spaced at a predetermined crank angle and are equally spaced at other crank angles, and the unequal interval is provided at two opposing positions at every crank angle of 180 °. A cylinder discrimination device for an internal combustion engine,
Means for detecting a signal based on the non-uniformly spaced portion with the crank angle sensor; and means for detecting a signal based on the cam signal plate with a cam angle sensor;
Combination of the number of cam angle sensor signals detected between two consecutive crank signal unequal intervals and the number of cam angle sensor signals detected between the next consecutive crank signal unequal intervals Cylinder determination device that performs cylinder determination based on 2. The cylinder determining device for an engine according to claim 1, wherein the positions of the concave group or the convex group of the cam signal plate and the unequally spaced portion of the crank signal plate are arranged with an angular difference. . In the cylinder determining device, means for storing time intervals of crank signals generated and detected based on the crank signal plate as t3, t2 and t1 for each generation order, and using the t3, t2 and t1, the following formula: 2. The cylinder determination device according to claim 1, wherein unequally spaced positions of the crank signal are identified by an AND condition of 1 and Formula 2.
t2 / t1> A1 Formula 1
t2 / t3> A2 Formula 2
t1: Time between latest crank signals
t2: Time between previous crank signals
t3: Time before the crank signal   An internal combustion engine comprising a controller including the cylinder determination device according to claim 1, further comprising variable valve timing means for controlling variable valve timing by a signal based on the cam signal plate.   An internal combustion engine comprising a controller including the cylinder determination device according to claim 1, wherein the controller performs an engine misfire diagnosis using the crank signal.

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