JP2595848B2 - Cylinder discrimination detection device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder discriminating and detecting device for an internal combustion engine, and more particularly to a cylinder discriminating and detecting device having improved cylinder discriminating detection accuracy when starting a four-cycle internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as a cylinder discriminating method for an internal combustion engine, as shown in Japanese Patent Application Laid-Open No. Hei 1-203656, a cylinder discriminating projection is provided on each of two rotating bodies rotating together with a crankshaft and a camshaft. And a method of detecting the rotation angle position of the engine from a signal generated by a detection element provided in the vicinity of the locus of each protrusion of two rotating bodies.

[0003]

Generally, in a four-stroke internal combustion engine, a cycle of four strokes of intake, compression, expansion and exhaust is completed by two revolutions of the crankshaft. Cylinder discrimination cannot be performed. Therefore, in the case where the cylinder discrimination is performed only by the projection provided on the rotating body that rotates together with the crankshaft, for example, in the case of a six-cylinder internal combustion engine, it can be determined that the cylinder is any one of the first cylinder and the sixth cylinder. It is not possible to clearly determine which cylinder is the cylinder or the sixth cylinder.

For this reason, as shown in the above-mentioned Japanese Patent Application Laid-Open No. Hei 1-203656, the position and configuration of a cylinder discriminating detection or rotation angle position detection projection provided on each rotating body which rotates together with a crankshaft and a camshaft. With only the above, when a signal generated by one of the first detection element and the second detection element provided on each rotating body of the crankshaft and the camshaft is a failure (abnormal), appropriate cylinder discrimination can be performed. There is no problem.

[0005] Further, since the cylinder discrimination of the internal combustion engine cannot be accurately performed unless the crankshaft rotates more than two times at the start of the internal combustion engine, the cylinder discrimination signal and the rotation angle position signal are output early after cranking starts. Since the fuel injection control based on the above cannot be precisely controlled, there is a problem that startability is deteriorated. The present invention has been made in order to solve such a problem. Even if one of the signals generated by the two detection elements for detecting the rotational positions of the crankshaft and the camshaft becomes abnormal, the other signal becomes abnormal. Provided is a cylinder discrimination detecting device capable of accurately detecting a cylinder discrimination and a rotation angle position by a signal, and improving a startability of the internal combustion engine by enabling a cylinder discrimination within one revolution of a crankshaft of the internal combustion engine. With the goal.

[0006]

According to the present invention, there is provided a cylinder discriminating and detecting apparatus for an internal combustion engine according to the present invention, wherein the first rotating body rotates in synchronization with a crankshaft of the internal combustion engine and the camshaft. A plurality of detected parts formed at equal angular intervals around the outer periphery of the first rotator in a four-cycle internal combustion engine having a second rotator that rotates
A plurality of detected portions formed at equal angular intervals at an outer peripheral position of the second rotating body, a first reference position detected portion formed at a specific location of the outer peripheral position of the first rotating body so as to be able to distinguish the cylinder, A second reference position detection portion formed to be able to discriminate the cylinder at a specific position on the outer peripheral position of the two rotators, and provided near a rotation locus of the detection portion of the first rotator; A first detection element that generates a pulse each time it passes through, and is provided near the rotation locus of the detected part of the second rotating body,
A second detection element for generating a pulse each time the detected portion passes by the vicinity, and a control device for inputting signals generated by the first detection element and the second detection element, the first rotation element comprising: When a signal generated by the first reference position detection unit is input, a reference cylinder is set according to the number of pulses generated by the second rotating body during a predetermined period near the signal input, and the first detection element or the second A control device that detects a signal abnormality generated by one of the two detection elements and, when a signal abnormality generated by one of the detection elements is detected, sets a reference cylinder in accordance with a pulse generated by the other detection element; It is characterized by having.

[0007]

According to the cylinder discriminating and detecting device for an internal combustion engine according to the present invention, when the internal combustion engine is started, for example, whether the first cylinder or the sixth cylinder is discriminated from the rotational position of the crankshaft is determined by the reference position signal of the crankshaft. In order to determine whether or not the reference position signal of the camshaft has been generated during a predetermined period near the input, it is determined whether the cylinder is the first cylinder or the sixth cylinder within one revolution of the crankshaft.

[0008] Further, since the cylinder discrimination and the rotation angle position are detected independently by the detecting elements provided independently of the first rotating body and the second rotating body, a signal generated by one of the detecting elements is generated. Even if a failure occurs, the other detection element is backed up, so that control at the time of failure is not impaired, and the reliability of the control device is ensured.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. An embodiment in which the present invention is applied to a four-cycle six-cylinder internal combustion engine will be described. As shown in FIG. 1, a disk 2 is fixed to a crankshaft 1, and projections 3 are formed on the outer periphery of the disk 2 at every 15 ° crank angle. Then, of the protrusions 3 located on the same circumference, for example, the top dead center (T
The toothless portion 4 is formed in a portion corresponding to a reference position indicating DC) or the top dead center (TDC) of the sixth cylinder.

On the other hand, the camshaft 5 rotates in synchronization with the crankshaft 1 and the crankshaft 2
One rotation per rotation. The camshaft 5 has a disk 6 fixed on the same axis as the camshaft 5, and a projection 7 is formed on the outer circumference of the disk 6 at every 120 ° crank angle, that is, at every 60 ° on the outer circumference of the disk 6. Then, for example, an extra tooth 8 is formed immediately before the projection 7 corresponding to the reference position indicating the top dead center of the first cylinder.

The electromagnetic pickups 10 and 12 respectively include a projection 3 on the crankshaft 1 and a projection 7 on the camshaft 5.
And a signal is generated each time the extra tooth 8 passes.
The generated signal is input to the waveform shaping circuit 15. Each signal whose waveform is shaped by the waveform shaping circuit 15 is sent to a control device (CPU).
The CPU 16 calculates the cylinder discrimination and the crank angle based on each signal, and executes fuel injection control, ignition timing control, and the like based on the result of the calculation processing.

The cylinder discrimination and the rotation angle position of the internal combustion engine are discriminated as follows. As shown in FIG. 2, during the period t of four pulse signals before the pulse signal generated by the electromagnetic pickup 10 at a position corresponding to the toothless portion 4 of the crankshaft 1, the extra teeth 8 of the camshaft 5 are generated. Is determined by detecting whether the electromagnetic pickup 12 generates a pulse signal corresponding to the first cylinder or the sixth cylinder. In this case, when there is a pulse signal corresponding to the extra tooth 8 during the period t, the position corresponding to the pulse signal immediately after the detection of the missing tooth portion 4 indicates the top dead center of the first cylinder. That is, before the pulse signal 4 after the detection of the missing tooth portion 4 of the crankshaft 1,
If the pulse signal indicating the extra teeth 8 of the camshaft 5 is not detected during the period t in which the pulse signal is generated, the position where the pulse signal is generated immediately after the detection of the missing tooth portion 4 is set to the sixth position.
It is determined as the top dead center of the cylinder, and if a pulse signal indicating the extra teeth 8 is detected, it is determined as the top dead center of the first cylinder.

In this manner, during normal operation, it is determined whether the cylinder is the first cylinder or the sixth cylinder within one rotation of the crankshaft, and each rotation of the top dead center of the first cylinder or the top dead center of the sixth cylinder is determined. An angular position is detected. Next, FIG. 3 shows a fail determination method for determining a failure based on a signal generated by the first electromagnetic pickup 10 on the crankshaft side.

A pulse rising time t generated by the first electromagnetic pickup 10 according to the rotation of the crankshaft 1
Input _Ni (step 20). Next, the elapsed time T _NEi (= t _Ni −t) from the previous pulse rising time t _Ni-1
Ni-1 ) is calculated (step 21), and it is determined whether or not the elapsed time T _NEi is 0.5 seconds or more (step 2).
2). If it is determined that the elapsed time T _NEi ≧ 0.5 seconds, it is determined that the first rotating body pulse is abnormal (step 2).
3). If it is determined that the elapsed time T _NEi <0.5 seconds, it is determined whether or not the number of pulses input during the period of one rotation of the crankshaft before time t _Ni is 23 (step 30). The number of the 23 protrusions corresponds to the number of protrusions 3 formed on the disc 2.
Equal to the number of If this pulse input number is not 23, it is determined that the first rotating body pulse is abnormal (step 2).
3). If this pulse input number is 23, it is determined that the first rotating body pulse is normal (step 31). If the first rotating body pulse is normal, the rotation speed _NE is calculated (step 32).

FIG. 4 shows a cylinder discriminating method for discriminating a cylinder based on a signal generated by the first electromagnetic pickup 10 on the crankshaft side. The pulse rise time t _Ni generated by the first electromagnetic pickup 10 in accordance with the rotation of the crankshaft 1 is input (step 20). Next, the elapsed time T _NEi from the previous pulse rising time t _Ni-1
(= T _Ni −t _Ni-1 ) is calculated (step 21).

Next, the elapsed time T _NEi ≦ _3/2 × T _NEi-1
Is determined (step 24). Elapsed time T
If _{NEi ≦ 3/2 × T NEi} -1, the N _E pulse number +
One is added (step 26). T _NEi > _3/2 × T
If it is _NEi-1 , this N _Ei pulse signal is regarded as indicating the missing tooth portion 4, and this N _Ei pulse signal is replaced with a _NEO pulse signal (step 25). The position at which the N _Eo pulse signal is generated is regarded as the reference position of the rotation angle, for example, the top dead center position of the first cylinder (step 27). Since the reference position of the rotation angle is set for each rotation of the crankshaft, the reference position of the rotation angle is actually either the top dead center position of the first cylinder or the top dead center position of the sixth cylinder. At this position, the top dead center position of the first cylinder or the top dead center position of the sixth cylinder is determined.

[0017] Then, the rotational speed of the internal combustion engine within 2 seconds after setting the reference position of the rotation angle set in step 27 (N _E) to determine whether reached 400rpm larger rotational speed (step 28). If it is determined that the rotational speed N _E of the engine is greater than 400 rpm, it assumed that the starting of the internal combustion engine has been completed, or top dead center position of dead center position or the 6-cylinder on the first cylinder of the It is considered that the cylinder discrimination has been properly performed. Within 2 seconds after the setting of the reference position of the rotation angle, the rotation speed of the internal combustion engine becomes 400 rpm
If it is determined to be equal to or less than m, it is considered that the start of the internal combustion engine is in an incomplete state because the previous cylinder determination was erroneously determined, and the next _NE0 pulse is determined to be, for example, the reference position of the first cylinder. (Step 29). As a result, accurate cylinder discrimination is quickly performed after the ignition key is turned on, so that appropriate fuel injection control and ignition timing control are started early by an instruction of the ECU based on a proper cylinder discrimination signal. Startability is improved.

FIG. 5 shows a fail determination method for determining a failure based on a signal generated by the second electromagnetic pickup 12 on the camshaft side. The pulse rise time t _Gi generated by the second electromagnetic pickup 12 according to the rotation of the camshaft 5 is input (step 40). Next, the elapsed time T _Gi from the previous pulse rising time t _Gi-1
(= T _Gi −t _Gi−1 ) is calculated (step 41), and it is determined whether or not the elapsed time T _Gi is 4 seconds or more (step 4).
2).

If it is determined that the elapsed time T _Gi ≧ 4 seconds, it is determined that the pulse generated due to the rotation of the camshaft as the second rotating body is abnormal (step 43).
If it is determined that the elapsed time T _{Gi is} less than 4 seconds, it is determined whether or not the number of pulse inputs during the period of one rotation of the camshaft 5 before time t _Gi is seven (step 50). These seven numbers are equal to the sum of the number of projections 7 formed on the disk 6 and the number of extra teeth 8. If the number of pulse inputs is not seven, the second
It is determined that the pulse generated by the rotating body is abnormal (Step 4)
3). If this pulse input number is seven, it is determined that the pulse generated by the second rotating body is normal (step 5).
1). If the pulse generated by the second rotating body is normal,
The rotational speed _NE is calculated (step 52).

FIG. 6 shows a cylinder discriminating method for discriminating a cylinder based on a signal generated by the second electromagnetic pickup 12 on the camshaft side. The pulse rise time t _Gi generated by the second electromagnetic pickup 12 according to the rotation of the camshaft 5 is input (step 40). Next, the elapsed time T _Gi (= t _Gi −) from the previous pulse rising time t _Gi-1
t _Gi-1 ) is calculated (step 41). Next, it is determined whether or not the elapsed time T _Gi ≦ １ ／ × T _Gi−1 (step 44). If the elapsed time T _Gi ≦ 1/2 × T _Gi−1 , G
+1 is added to the _E pulse number (step 45). T _Gi >
If 1/2 × T _Gi-1, the G _i pulse signal assumes indicating extra teeth 8, replacing the G _i pulse signal G ₀ pulse signal (step 46). The position where the _G0 pulse signal is generated indicates a reference position of the rotation angle, for example, the top dead center position of the first cylinder (step 47).

Here, the cylinder determined from the extra teeth 8 on the camshaft side is a specific single cylinder, and is classified into a first cylinder and a sixth cylinder as shown in step 27 of FIG. The cylinder is not determined by alternative unclear determination.
Intake, compression,
This is because one cycle of four strokes of expansion and exhaust corresponds to one rotation of the camshaft.

According to the above-described embodiment, the method for detecting the cylinder and detecting the rotational angle position independently from the respective rotational states of the crankshaft and the camshaft is employed, so that the first electromagnetic pickup 10 on the crankshaft side fails. In the meantime, the cylinder discrimination can be performed by the second electromagnetic pickup 12 on the camshaft side. On the contrary, when the second electromagnetic pickup 12 on the camshaft side fails, the detection of the first electromagnetic pickup 10 on the crankshaft side is performed. The cylinder determination and the rotation angle position can be detected by the signal. Therefore, even if one of the first electromagnetic pickups 10 and 12 fails, the cylinder discrimination and the rotation angle position can be accurately detected by the signal of the other electromagnetic pickup.

When the internal combustion engine is started, the rotational position of the reference cylinder can be determined within a period in which the crankshaft makes one revolution after the start of cranking. Therefore, the control of the fuel amount and the injection timing is performed for each cylinder by a command from the control device. Since idling can be quickly and accurately performed, idling can be quickly shifted to a stable state. In the above-described embodiment, the toothless portion 4 and the extra tooth 8 formed on each of the discs 2 and 6 of the crankshaft 1 and the camshaft 5 are provided one by one. The number of missing teeth and extra teeth formed on each disk is not limited, and a plurality of teeth may be set. It is also possible to provide extra teeth on the first rotating body on the crankshaft side and provide missing teeth on the second rotating body on the camshaft side.

[0024]

As described above, according to the cylinder discrimination detecting device of the internal combustion engine of the present invention, the cylinder discrimination reference position is detected within one revolution of the crankshaft of the internal combustion engine. In addition, there is an effect that the fuel injection control can be accurately controlled at an early stage, the startability can be improved, and a stable idling state after the start can be secured.

Further, since the first rotating body and the second rotating body provided on the crankshaft and the camshaft are provided with the detection parts for detecting the cylinder and detecting the rotation angle position independently of each other, one of the detection means is provided. Even if the signal generated by the element becomes abnormal, the cylinder detection and the rotation angle position are detected by the signal generated by the other detection element, so that the backup function at the time of a failure is secured and the reliability of the internal combustion engine is improved. There is.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram illustrating signals generated by two electromagnetic pickups according to an embodiment of the present invention.

FIG. 3 is a flowchart illustrating a determination method for detecting an abnormality of a pulse generated with rotation of a crankshaft according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a determination method for performing cylinder determination from a pulse generated with rotation of a crankshaft according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a determination method for detecting an abnormality of a pulse generated due to rotation of a camshaft according to an embodiment of the present invention.

FIG. 6 is a flowchart showing a determination method for performing cylinder determination from a pulse generated with rotation of a camshaft according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Disk (1st rotating body) 3 Projection (detected part) 4 Missing tooth part (1st reference position detected part) 5 Camshaft 6 Disk (2nd rotating body) 7 Projection (detected part) 8) Extra teeth (second reference position detected part) 10 Electromagnetic pickup (first detection element) 12 Electromagnetic pickup (second detection element) 16 ECU (control device)

Claims (1)

(57) [Claims] 1. A four-stroke internal combustion engine having a first rotating body that rotates in synchronization with a crankshaft of an internal combustion engine and a second rotating body that rotates in synchronization with a camshaft, and an outer peripheral position of the first rotating body. A plurality of detected parts formed at equal angular intervals on the outer peripheral position of the second rotating body; a plurality of detected parts formed at equal angular intervals on the outer peripheral position of the second rotating body; A first reference position detected portion formed so as to be capable of being detected; a second reference position detected portion formed so as to be able to determine a cylinder at a specific location of an outer peripheral position of the second rotating body; and the detected state of the first rotating body. A first detection element that is provided near the rotation locus of the detected portion of the second rotating body and is provided near the rotation locus of the detected portion of the second rotating body. Generates a pulse every time the detector passes by A second sensing element, and a control device for inputting signals generated by the first sensing element and the second sensing element, respectively, wherein a signal generated by a first reference position detected portion of the first rotating body is input. Setting a reference cylinder in accordance with the number of pulses generated by the second rotating body during a predetermined period near the signal input, and detecting a signal abnormality generated by one of the first detection element or the second detection element and, when the signal generated by the one sensing device abnormality is detected, the cylinder identification of the internal combustion engine, characterized in that it comprises a control device for the setting of the reference cylinder in accordance with a pulse the other sensing element is generated Detection device.