JP4968030B2 - Cylinder discrimination device for internal combustion engine - Google Patents

Description

  The present invention relates to a cylinder discriminating apparatus for an internal combustion engine that discriminates cylinders of a four-cycle multi-cylinder engine.

  In a four-cycle engine, four steps of intake, compression, combustion, and exhaust are performed in order while the crankshaft rotates twice. In a 4-cycle multi-cylinder engine, in order to control ignition timing, fuel injection timing, and the like, it is necessary to accurately determine which process each cylinder is in, in other words, which cylinder should be ignited.

As this cylinder discrimination device, there are ones described in Patent Document 1 and Patent Document 2. The cylinder discriminating devices described in these patent documents provide a protrusion near the outer periphery of a rotating member that rotates integrally with the crankshaft, detects the crankshaft rotation angle by detecting the protrusion with a crank angle sensor, and A protrusion is provided in the vicinity of the outer peripheral portion of the rotating member that rotates integrally with the cam shaft, the protrusion is detected by a cam angle sensor, and the cylinder is discriminated based on these two detection signals.
JP 2004-103881 A JP-A-10-47109

  In addition to those described in Patent Documents 1 and 2, there are various cylinder discriminating devices that differ in the type of sensor, the number of sensors, the protrusion configuration of the rotating member, etc., but all of these discriminating cylinders are slow when starting the engine. It takes a long time to start the engine. In addition, if the camshaft is out of phase with the crankshaft due to a drive sprocket that is integrated with the crankshaft or a timing chain that is wound between the camshaft and the driven sprocket that is integrated with the camshaft, the cylinder is misidentified. The engine could be damaged by misignition. Furthermore, when a sensor is installed for each cylinder, a plurality of sensors are used, resulting in an expensive device.

  An object of the present invention has been made in consideration of the above-described circumstances, and is a cylinder discrimination device for an internal combustion engine that can quickly start an internal combustion engine by performing cylinder discrimination in a short time and can realize an inexpensive configuration. It is to provide.

  Another object of the present invention is to provide a cylinder discrimination device for an internal combustion engine that can reliably prevent erroneous ignition even when the phase of the camshaft is deviated from the crankshaft.

  Still another object of the present invention is to provide a cylinder discriminating device for an internal combustion engine that can reduce the fuel consumption and can suppress the discharge of unburned gas.

The present invention provides a crank angle for outputting a crank signal by detecting a plurality of crank detection portions provided at equal intervals on an outer peripheral portion of a rotating member provided integrally with a crankshaft, except for unequal intervals. A plurality of cam detectors formed in a unique pattern for each cylinder are detected on the outer periphery of the rotation member provided integrally with the sensor and the camshaft for driving the valve operating device, A four-cycle multi-cylinder internal combustion engine having a cam angle sensor for outputting a cam signal of a pattern, each of which includes one crank angle sensor and one cam angle sensor, wherein a plurality of crank signals are arranged. In the row, a non-signal portion where no crank signal is output corresponding to the unequal interval portion is provided in the same phase from the top dead center of each cylinder and at a substantially intermediate position between these top dead centers. In sets of three or more of the plurality of sections having the same phase with respect to the non-signal portion, by a combination of the presence or absence of the cam signal in the plurality of sections, is configured to perform discrimination of the cylinders Rutotomoni, a plurality of The combination of the cam signals in the section is set to a pattern that is not a combination of regular cylinder discrimination twice consecutively when the phase of the camshaft is deviated from the crankshaft. It is.

  According to the present invention, the cylinder is discriminated based on the combination of the presence or absence of the cam signal in a plurality of three or more sections set in the crank signal train, so that the internal combustion engine can be started early by performing the cylinder discrimination in a short time. Since one crank angle sensor and one cam angle sensor are provided, an inexpensive configuration can be realized.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a side view showing a four-cycle engine of an outboard motor to which an embodiment of a cylinder discrimination device for an internal combustion engine according to the present invention is applied. FIG. 2 is a bottom view of the engine of FIG.

  The engine (internal combustion engine) 10 of this outboard motor is a four-cycle type water-cooled in-line four-cylinder gasoline engine, and is mounted on the outboard motor vertically so that the crankshaft 15 faces the vertical direction. In the engine 10, the right side of FIG.

  The engine 10 is configured such that a crankcase 11, a cylinder block 12, a cylinder head 13, and a head cover 14 are fixed in order from the front side, and a crankshaft 15 is pivotally supported between the crankcase 11 and the cylinder block 12. . The cylinder head 13 accommodates a valve operating device including an intake valve (not shown), an exhaust valve 16, an intake cam (not shown), and an exhaust cam 17. An intake camshaft 18 and an exhaust camshaft 19 that drive the valve gear are pivotally supported by the cylinder head 13.

  In the cylinder block 12, four cylinders (cylinders) # 1, # 2, # 3, and # 4 extending in the horizontal direction are sequentially arranged in the vertical direction, and the piston 20 can reciprocate in each cylinder # 1 to # 4. Is housed. These pistons 20 are connected to the crankshaft 15 via connecting rods 21, and the reciprocating motion of the piston 20 is converted into the rotational motion of the crankshaft 15. The crankshaft 15 is connected to a drive shaft 24 through gears 22 and 23, and power is transmitted to the drive shaft 24.

  In the cylinder head 13, combustion chambers 25 are formed so as to communicate with the respective cylinders # 1 to # 4, and intake valves and exhaust valves 16 are arranged facing these combustion chambers 25. Further, the cylinder head 13 is provided with ignition plugs 26 facing the combustion chamber 25, and these ignition plugs 26 are connected to ignition coils 27 corresponding to the respective ignition plugs 26. Each intake port (not shown) reaching each combustion chamber 25 is provided with an injector (not shown) for injecting fuel upstream of the intake valve.

  Incidentally, a flywheel 28 as a rotating member is provided at the upper end of the crankshaft 15 so as to rotate integrally. A large-diameter ring gear 29 is fixed to the outer periphery of the flywheel 28 in a hook shape, and several permanent magnets 30 are fixed to the inner periphery of the flywheel 28.

  On the other hand, a stator 31 located in the flywheel 28 is fixed to the upper surfaces of the crankcase 11 and the cylinder block 12. The flywheel 28, the permanent magnet 30 and the stator 31 constitute a flywheel magneto device 32 that functions as a generator.

  Further, as shown in FIG. 2, a winding transmission mechanism 34 is provided on the lower surface of the engine 10. The winding transmission mechanism 34 includes a drive sprocket 35 provided integrally with the drive shaft 24, an intake-side driven sprocket 36 provided integrally with the intake-side cam shaft 18 and the exhaust-side cam shaft 19, and an exhaust side. A driven sprocket 37 and a timing chain 38 wound between the sprockets 35, 36 and 37 are configured.

  By this winding transmission mechanism 34, the rotation of the crankshaft 15 is transmitted to the camshafts 18 and 19 via the drive shaft 24. The timing chain 38 is guided by the chain guide 33 and loosened by the chain tensioner 39.

  Furthermore, a starter motor for starting the engine (not shown) is installed in the crankcase 11. A small-diameter pinion gear (not shown) is provided on the starter motor. The pinion gear protrudes toward the ring gear 29 of the flywheel 28 and can be engaged with the ring gear 29.

  When the starter motor is operated, the pinion gear protrudes toward the ring gear 29 and meshes with the ring gear 29, and the power of the starter motor is transmitted to the crankshaft 15 to start the engine 10.

  When the engine 10 is started, the rotation of the crankshaft 15 is transmitted to the camshafts 18 and 19 via the winding transmission mechanism 34, and the valve gear built in the cylinder head 13 is driven.

  In the present embodiment, the number of teeth of the gear 22 connecting the crankshaft 15 and the drive shaft 24 is set to be smaller than the number of teeth of the gear 23, and the drive shaft 24 is rotated by being decelerated from the crankshaft 15. The ratio between the number of teeth of the drive sprocket 35 and the number of teeth of both driven sprockets 36 and 37 is set to be smaller than 1: 2, and finally the camshafts 18, 19 are rotated while the crankshaft 15 makes two revolutions. Is set to rotate once, and four strokes of intake, compression, combustion, and exhaust per cylinder of the engine 10 are executed in order.

  In the engine 10, the ignition control and fuel injection timing of each cylinder (cylinder) # 1 to # 4 are appropriately set and the operation control is executed. In order to appropriately perform these controls, the engine 10 is provided with a cylinder discrimination device 40. This cylinder discriminating device 40 discriminates which cylinder # 1 to # 4 is in the intake, compression, combustion, or exhaust process, in other words, which cylinder should be ignited. The cylinder discrimination device 40 includes a crank angle sensor 41, a cam angle sensor 42, and a determination / control circuit 43.

  As shown in FIGS. 1 and 3, the crank angle sensor 41 is a crank detector disposed at equal intervals on the outer peripheral portion of the flywheel 28 provided integrally with the crankshaft 15 except for the unequal interval portion 45. As a result, the crank signal P (FIG. 5) is output. One crank angle sensor 41 is installed on the engine 10 main body side, for example, the crankcase 11.

  The crank protrusions 44 are provided on the outer periphery of the flywheel 28 at regular intervals for every rotation angle of about 10 degrees. Further, the non-uniformly spaced portions 45 are arranged at two locations on the outer peripheral portion of the flywheel 28 at intervals of about a rotation angle of 180 degrees. The crank angle sensor 41 is disposed to face the crank protrusion 44 of the flywheel 28 and outputs a crank signal P when the crank protrusion 44 is detected by the rotation of the flywheel 28. The crank angle sensor 41 does not output the crank signal P when facing the non-uniformly spaced portion 45. The crank signal P detected by the crank angle sensor 41 is transmitted to the discrimination / control circuit 43.

  The train of crank signals P (crank signal train) transmitted to the discrimination / control circuit 43 is as shown in FIG. 5, and the crank signal P is not output corresponding to the unequal interval portion 45 by the non-signal portion 46. A shaft rotation angle is detected. The position of the non-signal portion 46 is determined by a period ratio with the equally spaced crank signal P. Further, the non-signal portion 46 is provided at a position of the same phase α from the top dead center of each of the cylinders # 1 to # 4 in the crank signal train and at a substantially intermediate position between these top dead centers.

  By disposing the non-signal portion 46 at a substantially intermediate position between the top dead centers of the cylinders # 1 to # 4, when determining the non-signal portion 46 based on the cycle ratio with the crank signal P, the compression of the engine 10 It becomes difficult to be affected by rotational fluctuations due to combustion, and the possibility of erroneous determination of the non-signal portion 46 is reduced. Further, since the non-signal portion 46 does not exist in the vicinity of the ignition timing that is substantially in phase with the top dead center of each of the cylinders # 1 to # 4, ignition can be executed with accurate timing by the equally spaced crank signal P.

  As shown in FIG. 5, in the crank signal train, three or more sections (three in the present embodiment) having the same phase are obtained by using the crank signal P at equal intervals with the non-signal portion 46 as a reference. Sections A, B, and C) are set. The sections A, B, and C are set to have the same phase from each top dead center by using the non-signal portion 46 at the same phase α from the top dead center of each cylinder # 1 to # 4 as a reference. Is done.

As shown in FIGS. 1 and 4, a sensing rotor 47 is rotatably integrated with a camshaft for driving a valve operating apparatus, in this embodiment, an exhaust camshaft 19 for driving the exhaust valve 16 and the like. . One cam angle sensor 42 is installed on the main body side of the engine 10, for example, on the cylinder head 13 or the head cover 14, and detects a cam protrusion 48 as a cam detection portion formed on the outer periphery of the sensing rotor 47. The cam projection 48 is formed in a unique pattern for each of the cylinders # 1 to # 4.

  That is, three cam protrusions 48a, 48b, and 48c are continuously formed at equal intervals corresponding to cylinder # 1, and one cam protrusion 48d is formed corresponding to cylinder # 3. Two cam projections 48e and 48f are formed corresponding to the cylinder # 4, and two cam projections 48g and 48h are formed corresponding to the cylinder # 2. The cam protrusion 48d is formed at a position of 90 degrees with the cam protrusion 48c. The cam protrusion 48e is formed at a position of 180 degrees with respect to the cam protrusion 48b, and the cam protrusion 48f is formed at a position of 180 degrees with respect to the cam protrusion 48c. The cam protrusion 48g is formed at a position of 270 degrees with respect to the cam protrusion 48a, and the cam protrusion 48h is formed at a position of 270 degrees with respect to the cam protrusion 48c.

  The cam angle sensor 42 detects the cam protrusions 48 (48a to 48h) and outputs a cam signal Q (see FIG. 5) having a unique pattern for each of the cylinders # 1 to # 4. 43. All the cam signals Q are adjusted so as to fall within the sections A, B, and C set in the crank signal train.

  The cam signal Q when the cam angle sensor 42 detects the cam protrusions 48a, 48b, and 48c is a pattern that exists in all the sections A, B, and C, and corresponds to the cylinder # 1. The cam signal Q when the cam angle sensor 42 detects the cam protrusion 48c is a pattern that exists in the section C, and corresponds to the cylinder # 3. Further, the cam signal Q when the cam angle sensor 42 detects the cam protrusions 48e and 48f is a pattern existing in the sections B and C, and is a pattern corresponding to the cylinder # 4. The cam signal Q when the cam angle sensor 42 detects the cam protrusions 48g and 48h is a pattern existing in the sections A and C, and corresponds to the cylinder # 2.

  The discrimination / control circuit 43 executes cylinder discrimination based on the combination of the cam signals Q in the sections A, B, and C. That is, as shown in FIGS. 6A and 7A, the discrimination / control circuit 43 discriminates cylinder # 1 in the combination where the cam signal Q exists in all of the sections A, B, and C. To do. Further, the discrimination / control circuit 43 discriminates the cylinder # 3 in the combination in which the cam signal Q exists only in the section C. Further, the discrimination / control circuit 43 discriminates the cylinder # 4 in a combination in which the cam signal Q exists in the sections B and C. Further, the discrimination / control circuit 43 discriminates the cylinder # 2 in the combination where the cam signal Q exists in the sections A and C.

  Here, the cam signal Q output based on the cam protrusion 48 is obtained when the phases of the intake camshaft 18 and the exhaust camshaft 19 are shifted to the advance side or the retard side with respect to the crankshaft 15. The pattern is set so as not to be a combination of regular cylinder discrimination twice in succession. For example, the cam signal Q is always present in one specific section (section C in the present embodiment) among the sections A, B, and C (the cam signal Q is present).

  By doing so, when the phases of the intake camshaft 18 and the exhaust camshaft 19 are shifted to the advance side with respect to the crankshaft 15, they are shown in FIGS. 6B and 7B. As described above, since the cam signal Q does not exist in the section C, it is impossible to determine the cylinders for all the cylinders # 1 to # 4. Further, when the phases of the camshafts 18 and 19 are shifted to the retard side with respect to the crankshaft 15, the cam signal Q exists in the section A as shown in FIGS. 6 (C) and 7 (C). Therefore, regular (correct) cylinder discrimination is not performed, and it is impossible to discriminate the cylinders twice in succession.

  As shown in FIG. 5, the discrimination / control circuit 43 further injects fuel into the cylinder # 1, # 2, # 3 or # 4 that has been discriminated when the cylinder discrimination is executed once, When regular cylinder discrimination is executed twice in succession, ignition is performed on the cylinder # 1, # 2, # 3 or # 4 which is first discriminated. Therefore, when the camshafts 18 and 19 are shifted in phase toward the advance side or retard side with respect to the crankshaft 15, regular cylinder discrimination is not executed twice in succession. The cylinders # 1 to # 4 are not ignited.

  The above-described cylinder discrimination, fuel injection, and ignition executed by the discrimination / control circuit 43 will be described when the engine 10 is started, taking the cylinder # 1 as an example.

  Here, the ignition order of the four cylinders # 1 to # 4 of the engine 10 is, for example, in the order of # 1 → # 3 → # 4 → # 2, and when the exhaust stroke is executed in the cylinder # 1 The combustion stroke is executed in cylinder # 3, the compression stroke is executed in cylinder # 4, and the intake stroke is executed in cylinder # 2.

  When the starter motor is turned on, the crank signal P and the cam signal Q become unstable immediately after the starter motor is turned on. Therefore, the crank signal P and the cam signal Q are ignored for a certain period M. Next, in the exhaust process of the cylinder # 1, it is confirmed that the cam signal Q exists in all the sections A, B and C, and the cylinder discrimination is executed assuming that the cylinder to be ignited is the cylinder # 1 (1 Cylinder discrimination). Based on this first cylinder discrimination, fuel is injected into cylinder # 1 that has been discriminated.

  Next, in the intake process of the cylinder # 1, it is confirmed that the cam signal Q exists only in the section C, and the cylinder discrimination is performed assuming that the cylinder to be ignited is the cylinder # 3 (second cylinder discrimination). . After this regular cylinder discrimination is executed twice in succession, the cylinder # 1 that was first discriminated is ignited near the compression top dead center of the cylinder # 1.

  The ignition is performed after the normal cylinder discrimination is performed twice in succession, even if the cylinders # 1 to # 4 for injecting fuel are mistaken, but the engine 10 is not damaged, but the cylinder # 1 to be ignited This is because if the # 4 is wrong, the engine 10 may be damaged by a backfire or the like. For this reason, even when the phases of the camshafts 18 and 19 are deviated from the crankshaft 15, the ignition is not performed, so that the engine 10 is prevented from being damaged.

  Further, as shown in FIG. 5, the pattern of the cam signal Q output based on the cam protrusion 48 is the upper in each cylinder # 1 to # 4 in the sections A, B and C set in the crank signal train. The cam signal Q is always present in the section in the vicinity of the dead center (section C in the present embodiment) (the cam signal Q is present). Thereby, even when the crank angle sensor 41 fails and the crank signal P is not output, the cylinders # 1 to # 4 are ignited based on the cam signal Q at the top dead center, and the engine 10 is operated. Is possible.

  Cylinder discrimination, fuel injection, and ignition executed by the discrimination / control circuit 43 when the crank angle sensor 41 fails will be described with reference to FIGS.

  When the starter motor is turned on, it is confirmed that the cam signal Q is input, and the cycle ratios a / b, b / c, c / d,... Are calculated for each cam signal Q. Then, the magnitude relationship between each cycle ratio and the cycle ratio immediately before the cycle ratio is compared, and the cylinder is determined from the arrangement of these magnitude relationships.

  For example, when the current cycle ratio is smaller than the previous cycle ratio, cylinder # 1 is discriminated at the time of the cam signal Q1 when two consecutive times occur, and the next cam signal Q2 after this cylinder discrimination is obtained. The energization start timing for the cylinder # 1 determined as the cylinder is set, and the next cam signal Q3 is set as the ignition timing of the cylinder # 1. For the cylinders in which the cam signal Q does not exist at the energization start timing, energization is started by setting the timer according to the time from the cam signal Q4 immediately before the cam signal Q5 serving as the ignition timing.

  In this way, after the cam signal Q1 is input and the cylinder # 1 is discriminated, the pattern of the cam signal Q input thereafter is known, so that it is output at the top dead center of each cylinder # 1 to # 4. The cam signal before the cam signal Q is used as the energization start timing or the start timing of the energization start timing setting timer. Therefore, even when the two cam signals Q6 and Q7 are output before the cam signal Q8 output at the top dead center, the cam signal Q7 immediately before the cam signal Q8 is set as the energization start timing.

  The fuel injection is executed after the cylinder discrimination in the cam signal Q1 is completed and the cam signals Q1, Q3, Q5, Q8... Output at the top dead center of each cylinder # 1 to # 4 are confirmed. When it is desired to start the engine 10 earlier, fuel is injected into all the cylinders # 1 to # 4 in synchronization with the first cam signal Q0.

  Next, the cylinder discrimination, fuel injection, and ignition operations executed by the discrimination / control circuit 43 of the cylinder discrimination device 40 will be described with reference to FIG.

  The discrimination / control circuit 43 confirms whether or not the cam signal Q has been input (S1), and if not, waits until it is confirmed. After confirming the cam signal Q, the discrimination / control circuit 43 confirms whether or not the crank signal P has been input (S2), and if so, detects the non-signal portion 46 of the crank signal train (S3).

  After detection of the non-signal portion 46, sections A, B, and C are set in the crank signal train, and the first cylinder discrimination is executed from the combination of the presence or absence of the cam signal Q in these sections A, B, and C (S4). . After executing this cylinder discrimination, fuel is injected only into the discriminated cylinder (S5).

  Next, the second cylinder discrimination is executed from the combination of the presence or absence of the cam signal Q in the sections A, B, and C of the crank signal train (S6). When the second cylinder discrimination is executed, the first discriminated cylinder is ignited (S7). If the second cylinder discrimination cannot be executed, the process returns to step S1 without performing ignition.

  When it is confirmed in step S2 that the crank signal P does not exist, a cycle ratio is calculated for the cam signal Q, and cylinder discrimination is executed from the magnitude relationship of these cycle ratios (S8). After the cylinder discrimination in step S8 is performed, fuel is injected into the corresponding cylinders # 1 to # 4A, and ignition is performed. The cylinder discrimination in step S8 is repeated until it can be executed.

  With the configuration as described above, the following effects (1) to (6) are achieved according to the present embodiment.

  (1) Since the cylinders # 1 to # 4 are discriminated based on the combination of the presence or absence of the cam signal Q in the sections A, B, and C set in the crank signal train, the cylinder discrimination is performed in a short time, and the engine 10 is started early. Can be started. That is, the engine 10 can be started within two revolutions of the crankshaft 15. The process from cylinder discrimination to fuel injection, intake, compression, and ignition to the discriminated cylinder theoretically requires one or more revolutions of the crankshaft 15. Therefore, the engine is within one revolution of the crankshaft 15 from the cylinder discrimination. It is impossible to start 10. Therefore, starting the engine 10 within two revolutions of the crankshaft 15 can start the engine 10 in a very short time.

  (2) Even in the case of a multi-cylinder engine such as the engine 10, only one crank angle sensor 41 and one cam angle sensor 42 need be installed, and a plurality of crank angle sensors 41 and cam angles corresponding to the cylinders. Since the sensor 42 is not necessary, the cylinder discriminating apparatus 40 having an inexpensive configuration can be realized.

  (3) When the phase of the cam shafts 18 and 19 is shifted to the advance side or the retard side with respect to the crank shaft 15, the cam signal Q has a pattern that does not form a combination of regular cylinder discrimination twice consecutively. The discrimination / control circuit 43 is configured to ignite the cylinder first discriminated when the normal cylinder discrimination is executed twice in succession. Therefore, when the phases of the camshafts 18 and 19 are deviated from the crankshaft 15, no ignition is performed on any of the cylinders # 1 to # 4, and erroneous ignition can be reliably prevented. Further, it is possible to prevent damage due to the backfire of the engine 10 or the like.

  (4) Since the fuel is injected only into the determined cylinder when the cylinder determination is performed, the fuel consumption can be reduced as compared with the case where the fuel is uniformly injected into all the cylinders regardless of the cylinder determination. Particularly, it is possible to prevent unburned gas from being discharged when the engine is started.

  (5) The pattern of the cam signal Q is that the cam signal Q is in a section (for example, section C) in the vicinity of the top dead center in each of the cylinders # 1 to # 4 among the sections A, B, and C set in the crank signal train. Since the crank angle sensor 41 fails and the crank signal P is not output, the cam signal Q (cam signal Q1) that is output at the top dead center of each cylinder # 1 to # 4 is provided. , Q3, Q5...), The engine 10 can be started by igniting each cylinder # 1 to # 4.

  (6) The cam signal Q (cam signals Q2, Q4, Q7,...) Output before the cam signal Q (cam signals Q1, Q3, Q5...) Output at the top dead center of each cylinder # 1 to # 4. ...) can be used to accurately set the energization start timing and the start timing of the energization start timing setting timer.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this. For example, in the present embodiment, the present invention is described as being applied to a four-cylinder four-cycle engine, but the present invention can be similarly applied to a four-cycle engine having three to six cylinders.

  Specifically, in the case of three cylinders, three non-signal portions 46 are set by providing three non-uniformly spaced portions 45 every 120 degrees on the flywheel 28, and three sections A, B, C of the crank signal train are set. Cylinders # 1 to # 3 are discriminated based on the combination of the cam signal Q. Also in the case of a 6-cylinder engine, particularly a V-type 6-cylinder engine, three non-uniformly spaced portions 45 are provided every 120 degrees to set the non-signal portion 46, and the cam signal Q in the sections A, B, and C Cylinder discrimination is executed based on the combination. In this case, the top dead center position differs between the left and right cylinder rows of the V type, but the non-signal portion 46 by the unequal interval portion 46 only needs to be in the same phase from the top dead center of each cylinder row. Even if the angle (phase) from the point to the non-signal portion 46 is different between the left and right cylinder rows, the cylinder can be discriminated.

  In the present embodiment, the invention is applied to the engine 10 of the outboard motor. However, the invention is applied to an engine mounted on an automobile, a motorcycle, a snowmobile, a water bike, or the like. You can also.

1 is a side view showing a four-cycle engine of an outboard motor to which an embodiment of a cylinder discrimination device for an internal combustion engine according to the present invention is applied. The bottom view of the engine of FIG. The flywheel and crank angle sensor of FIG. 1 are shown, (A) is a bottom view, (B) is a side view. The sensing rotor and cam angle sensor of FIG. 1 are shown, (A) is a top view, (B) is a side view. The time chart which shows the relationship between the driving | running state of each cylinder of FIG. 1, a crank signal, a cam signal, fuel injection timing, ignition timing, etc. FIG. The time chart which shows the relationship between a crank signal and a cam signal when the phase of a camshaft is normal with respect to a crankshaft (A) and when it shifts (B, C). The presence / absence of a cam signal for the sections A, B, and C of the crank signal train and the cylinder discrimination result are shown. (A) is shown in FIG. 6 (A), (B) is shown in FIG. Chart corresponding to 6 (C). The time chart which shows the relationship between the driving | running state of each cylinder, a cam signal, fuel injection timing, ignition timing, etc. when a crank angle sensor fails. The chart which shows the period ratio of the cam signal of FIG. 8, and its magnitude relationship. The flowchart which shows the effect | action of one Embodiment in a cylinder discrimination | determination apparatus.

Explanation of symbols

10 Engine 15 Crankshaft 18 Intake camshaft 19 Exhaust camshaft 24 Drive shaft 28 Flywheel (rotating member)
40 Cylinder Discrimination Device 41 Crank Angle Sensor 42 Cam Angle Sensor 43 Discrimination / Control Circuit 44 Crank Protrusion (Crank Detection Unit)
45 Unequally spaced portion 46 Non-signal portion 47 Sensing rotor (rotating member)
48 Cam protrusion (cam detector)
A, B, C Section P Crank signal Q Cam signal α Phase # 1 to # 4 Cylinder (cylinder)

Claims (7)

A crank angle sensor that outputs a crank signal by detecting a plurality of crank detection portions provided at equal intervals on the outer peripheral portion of a rotating member provided integrally with the crankshaft, except for unequal interval portions;
A cam having a unique pattern for each cylinder is detected by detecting a plurality of cam detecting portions formed in a unique pattern for each cylinder on the outer peripheral portion of a rotating member provided integrally with a camshaft for driving the valve gear. A cam angle sensor that outputs a signal,
A four-cycle multi-cylinder internal combustion engine having one of each of these crank angle sensors and cam angle sensors,
In the crank signal train in which a large number of the crank signals are arranged, the non-signal portion where the crank signal is not output corresponding to the unequal interval portion is in the same phase from the top dead center of each cylinder and between these top dead centers. Is provided at approximately the middle position of
In this crank signal sequence, set a plurality of three or more sections having the same phase with reference to the non-signal part,
The combination of the presence or absence of the cam signal in the plurality of sections, Rutotomoni is configured to perform discrimination of the cylinders,
The combination of the cam signals in the plurality of sections is set to a pattern that is not a combination of regular cylinder discrimination twice in succession when the phase of the camshaft is deviated from the crankshaft. A cylinder discrimination device for an internal combustion engine. The cam signal is set to a pattern that is not a combination of regular cylinder discrimination twice in succession when the camshaft phase is shifted from the crankshaft, and normal cylinder discrimination is executed twice in succession. 2. The cylinder discrimination device for an internal combustion engine according to claim 1, wherein the first discrimination cylinder is ignited. 2. The internal combustion engine according to claim 1, wherein the cam signal pattern is provided such that the cam signal is present in one specific section among a plurality of sections set in the crank signal train. Cylinder discrimination device. 2. The cam signal pattern according to claim 1, wherein the cam signal is provided in a section near the top dead center in each cylinder among a plurality of sections set in the crank signal train. The cylinder discrimination apparatus of the internal combustion engine as described. 2. The cylinder discrimination apparatus for an internal combustion engine according to claim 1, wherein when the cylinder discrimination is executed once, fuel injection is performed on the discriminated cylinder. The pattern that is not a combination of regular cylinder discrimination twice in succession is a pattern in which a pattern corresponding to any cylinder in regular cylinder discrimination and a pattern not corresponding to any cylinder are alternately continued. The cylinder discrimination device for an internal combustion engine according to claim 1. 2. The cylinder discrimination device for an internal combustion engine according to claim 1, wherein the pattern that is not a combination of regular cylinder discrimination twice in succession is a pattern in which cylinder discrimination is impossible for all cylinders. .

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