JP3959950B2 - Engine control information detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine control information detection device including a variable valve timing control device that changes a valve timing by changing a rotation phase of a camshaft with respect to a crankshaft.
[0002]
[Prior art]
In an engine provided with a variable valve timing control device, there is one disclosed in Japanese Patent Application Laid-Open No. 11-31148, for detecting information necessary for control of the variable valve timing control device and other engine control.
This is because a crank angle sensor and a cam angle sensor are arranged opposite to each of the first signal member and the second signal member mounted on the cam shaft to detect the crank angle and the cam shaft rotation phase, and The cylinder is discriminated by recognizing the signal pattern generated by the sensor.
[0003]
[Problems to be solved by the invention]
However, in the above, in order to detect control information such as crank angle detection, camshaft rotation phase detection, and cylinder discrimination, two angle sensors and two circuits for processing sensor signals are required. The number of parts increased and the cost was high.
[0004]
In addition, since two sensors are arranged opposite to each of the two signal members for one camshaft, there is a disadvantage that the installation space is small and the restrictions on mounting become strict. It was.
SUMMARY OF THE INVENTION An object of the present invention is to provide an engine control information detection device that can reduce the number of components and signal processing system and reduce the installation space.
[0005]
[Means for Solving the Problems]
Therefore, the invention according to claim 1 is a control information detecting apparatus for an engine with a variable valve timing control apparatus for changing the valve timing by changing a rotational phase relative to the crankshaft of the camshaft, and the crankshaft a first signal member which is mounted to rotate synchronously, and adjacent to the first signal element, and a second signal member mounted so as to synchronize with the camshaft, facing the two signals member And an angle sensor that outputs a detection signal each time a detected portion provided on the two signal members passes , and the first signal member includes a predetermined signal for each cylinder. The first detected portions for the number of cylinders detected by the angle sensor at the crank angle position are provided, and the second detected portions are disposed in the vicinity of the specific first detected portion. On the other hand, the second signal member is provided with a third detected portion that is detected simultaneously with the first detected portion by the angle sensor when the variable valve timing control device is not operated, and the variable valve timing control device During the operation, the detection signal of the third detected portion is discriminated from the detection signals output from the angle sensor, and the time between the detection signal of the three detected portions and the detection signal before and after the detected signal. A rotation phase of the cam shaft with respect to the crankshaft is detected based on the interval .
[0007]
The invention according to claim 2 calculates a ratio of continuous time intervals as a signal cycle ratio, and determines a specific cylinder by a detection signal when the calculated signal cycle ratio becomes a predetermined value or exceeds a predetermined threshold value. The detection signal of the third detected portion is determined based on the determination result .
[0009]
The invention according to claim 3, wherein to determine the detection signal of the first detection target portion of the detected signal, the time from the time interval of the detection signal of the first portion to be detected - by the crank angle conversion line Ukoto, The crank angle position in each cylinder is detected.
The invention according to claim 4 is characterized in that one second detected portion corresponding to the specific first detected portion is provided in the second signal member.
[0010]
The invention according to claim 5 is characterized in that the second signal member is provided with as many third detected portions as the number of cylinders corresponding to each of the first detected portions .
The invention according to claim 6 is characterized in that the angle sensor is a Hall IC.
[0011]
The invention according to claim 7 is characterized in that the angle sensor is a magnetic pickup type sensor.
[0012]
【The invention's effect】
According to the first aspect of the present invention, since the rotational phase of the camshaft relative to the crankshaft can be detected based on the detection signal from one angle sensor, when adding a variable valve timing mechanism (VVT), the angle sensor There is no need to add, the number of parts and installation space can be reduced, and only one signal processing system is required.
[0014]
According to the second aspect of the present invention, the signal cycle ratio calculated from the detection signal of the second detected portion provided on the first signal member and the detection signal of the first detected portion around it is Therefore, when the signal cycle ratio becomes a predetermined value or exceeds a predetermined threshold value, a specific cylinder is determined by a detection signal, and the third target is determined based on the determination result. the detection signal of the detection unit can determine another to Rukoto.
[0016]
According to the third aspect of the present invention, the crank angle position of the first detected portion provided in the first signal member and the crank angle corresponding to the time interval of the detection signals are known. Conversion can be performed to detect the crank angle position.
According to the invention which concerns on Claim 4 , since the time interval which measures is the shortest, control can be simplified.
[0017]
According to the fifth aspect of the present invention, since the time interval indicating the VVT conversion angle can be detected for each cylinder, the detection accuracy of the VVT conversion angle is improved, and as a result, the VVT control accuracy (responsiveness, convergence) is improved.
According to the invention which concerns on Claim 6 , the to-be-detected part of a 1st signal member and the to-be-detected part of a 2nd signal member are detectable by the presence or absence of a magnetic field.
[0018]
According to the invention which concerns on Claim 7 , the to-be-detected part of a 1st signal member and the to-be-detected part of a 2nd signal member are detectable by the change of a magnetic field.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the system configuration diagram of FIG. 1, an air flow meter 3 for detecting an intake air flow rate Q is provided in an intake passage 2 of the engine 1, and an intake air amount Q is controlled by a throttle valve 4.
[0020]
Each cylinder of the engine 1 is provided with a fuel injection valve 6 for injecting fuel into the combustion chamber 5 and an ignition plug 7 for performing spark ignition. The fuel is supplied to the air sucked through the intake valve 8. Fuel is injected from the injection valve 6 to form an air-fuel mixture, which is ignited by spark ignition by the spark plug 7.
Exhaust gas from the engine 1 is discharged to the exhaust passage 10 via the exhaust valve 9 and released into the atmosphere via an exhaust purification catalyst and a muffler (not shown).
[0021]
The ECU (engine control unit) 20 incorporates a microcomputer, and controls the fuel injection amount by the fuel injection valve 6, the fuel injection timing, the ignition timing by the spark plug 7, etc. based on various input detection signals. It is carried out.
The intake valve 8 and the exhaust valve 9 are driven to open and close by cams provided on the intake side camshaft 11 and the exhaust side camshaft 12, respectively. The intake side camshaft 11 is provided with a variable valve timing mechanism 30 for advancing and retarding the valve opening / closing timing by changing the rotational phase of the camshaft with respect to a crankshaft (not shown).
[0022]
As shown in FIG. 2, the variable valve timing mechanism 30 is provided with a helical spline 22 between the intake side camshaft 11 and a rotating member 21 that is rotationally driven in conjunction with the crankshaft. The rotational phase of the intake camshaft 11 with respect to the member 21 is continuously changed. In addition, the most retarded angle side and the most advanced angle side of the camshaft rotation phase are each limited by a stopper. When no hydraulic pressure is generated (eg, when VVT is not operating), such as when starting, return is performed. It is held at the most retarded position by a spring.
[0023]
In the present embodiment, the variable valve timing mechanism 30 is configured to change the opening / closing timing of the intake valve 8, but may be configured to change the opening / closing timing of the exhaust valve 9 instead of the intake valve 8. Alternatively, the opening / closing timing of both the intake valve 8 and the exhaust valve 9 may be changed.
Here, as schematically shown in FIG. 3, a portion where the relative position (relative angle) of the variable valve timing mechanism 30 to the crankshaft is fixed, that is, a portion that rotates in synchronization with the crankshaft (in the drawing, The first signal member 31 is provided on the VVT fixing portion.
[0024]
A portion where the relative position (relative angle) relative to the crankshaft is movable (VVT movable portion in the figure), that is, a portion that rotates in synchronization with the camshaft, and is positioned adjacent to the first signal member 31. 32 is provided. Further, the angle sensor 33 is disposed so as to face both the signal members.
The first signal member 31 and the second signal member 32 are formed in a cylindrical shape having a flush outer peripheral surface, and rotate at half the rotational speed of the crankshaft.
[0025]
The first signal member 31 is provided with a convex portion (or a concave portion) that is detected by the angle sensor 33 at a predetermined crank position of each cylinder as a detected portion for cylinder discrimination and discriminates a specific cylinder. The convex part (or recessed part) used in order to do is provided. For example, in the present embodiment, since the engine is a four-cylinder engine, the convex portion b, every 180 ° (180 ° CA) in crank angle from the convex portion a detected by the angle sensor 33 at the top dead center of the first cylinder. c and d are provided, and a convex part e is provided at a position of 10 ° CA from the convex part a, and a total of five convex parts are provided (see FIG. 4A).
[0026]
Further, the second signal member 32 is provided with the same convex portion a ′ at the same rotation angle position as the convex portion a provided on the first signal member 31 when the VVT is not operated (FIG. 4). (See (B)).
Here, since the first signal member 31 and the second signal member 32 have the same outer peripheral surface, the convex portion of the first signal member 31 and the convex portion of the second signal member 32 are the angle sensor 33. A signal (for example, the presence or absence of a magnetic field or a change) detected when passing through the detection unit can be equally detected by one angle sensor 33. Therefore, the signal detected by the angle sensor 33 is a signal obtained by synthesizing signals from the detected portions of the signal members.
[0027]
The angle sensor 33 outputs the detected signal to the ECU 20, and the ECU 20 measures a time interval (hereinafter referred to as a signal cycle) from the previous signal detection every time the signal is detected, and the ratio of the continuous signal cycle. (Signal period ratio) is calculated, and necessary control information is detected.
Next, signals detected by the angle sensor 33 and the ECU 20 when configured as described above will be described.
[0028]
5 and 6 show the case where a Hall IC is used as the angle sensor 33 and a magnetic pickup type sensor is used.
When the VVT is not operating, the convex portion a detected at the top dead center of the first cylinder of the first signal member 31 and the convex portion a ′ of the second signal member 32 are detected by the angle sensor 33 as described above. Pass the part simultaneously.
[0029]
In this case, the ECU 20 detects these signals as one pulse (see FIGS. 5A and 6A).
At the start of advancement after the start of the VVT operation, the convex part a and the convex part a ′ overlap with each other without passing a gap and pass through the detection part of the angle sensor 33.
Even in this case, the pulse width increases, but the ECU 20 detects it as one pulse (see FIGS. 5B and 6B).
[0030]
When the angle is further advanced after the VVT operation, the convex part a and the convex part a ′ pass through the detection part of the angle sensor 33 with a gap.
Therefore, in this case, the ECU 20 detects these signals as two pulses (see FIGS. 5C and 6C).
From the above, for example, when ignition is performed in the order of # 1, # 3, # 4, and # 2 cylinders, the signal form and signal cycle ratio are as shown in FIG.
[0031]
As shown in FIGS. 7A and 7B, the signals detected by the ECU 20 from the detection of the convex portion a by one rotation of the crankshaft to the detection again are the progresses when the VVT is not operating and immediately after the start of the VVT operation. At the beginning of cornering, there are six, and five signal periods are measured.
When the camshaft is advanced to some extent after the VVT operation, as shown in FIG. 7C, there are seven signals detected by the ECU 20, and six signal cycles are measured.
[0032]
Here, when the VVT conversion angle is set to n ° (n ° CA advance angle), as shown in FIG. 8A, measurement is performed from the detection of the convex portion a by one rotation of the crankshaft to the detection again. The signal periods T1 to T6 indicate 10, 170, 180, 180, 180-n, and n (° CA) in this order, and the signal period ratio is as shown in FIG. 8B. Then, when each signal period ratio in this case is calculated, as shown in FIG. 9, in this embodiment, when the signal period ratio is calculated as T2 / T1, T3 / T2, T4 / T3, VVT Even if the conversion angle changes, the signal cycle ratio is constant.
[0033]
Therefore, when the signal cycle ratio becomes approximately 17 (T2 / T1), that is, when the signal cycle T2 is measured, the top dead center of the third cylinder is determined (this is used as a reference position).
Note that the signal cycle ratio may fluctuate somewhat during rotation fluctuation or during VVT operation, but the signal cycle ratio T2 / T1 is a sufficiently large value compared to other signal cycle ratios. By setting a threshold value (for example, 10), it can be reliably detected.
[0034]
In theory, when the amount of advance is very small, the signal period ratio T1 / T6 (10 / n) exceeds 17 (or a set threshold), but T6 is detected by the resolution of the timer. By making it impossible, erroneous determination can be prevented.
Next, it is determined whether the VVT is operating or not.
This determination determines whether the signal cycle ratio exceeds a threshold, detects a signal cycle ratio exceeding the threshold (that is, a reference position), and then detects a signal cycle ratio (reference position) exceeding the threshold again. This is done by counting the number of signals that have been input until this time.
[0035]
When the number of input signals is 4, it is determined that VVT is OFF (non-operation), and when the number of input signals is 5, VVT is ON (operation).
Each signal is discriminated as follows.
When VVT is not operating, the top dead center of the fourth cylinder, the top dead center of the second cylinder, and the top dead center of the first cylinder in the order of signals detected by the ECU after determining the top dead center (reference position) of the third cylinder. It can be determined by recognizing it as a signal indicating.
[0036]
In the case of VVT operation, the top dead center of the fourth cylinder, the top dead center of the second cylinder, the VVT signal, the top of the first cylinder in the order of signals detected by the ECU after determining the top dead center (reference position) of the third cylinder. It can be determined by recognizing it as a signal indicating a dead point.
Next, detection of the VVT conversion angle will be described.
After inputting the signal for determining the reference position, the signal period T6 indicating the VVT conversion angle and the signal period T5 measured immediately before are combined to indicate 180 ° CA.
[0037]
Therefore, the VVT conversion angle n can be calculated as n = 180 × T6 / (T5 + T6). In the present embodiment, it may be calculated from the ratio between the signal period T3 (or T4) indicating 180 ° CA and the signal period T5. In this case, the conversion angle can be detected before measuring the signal period T6 indicating the VVT conversion angle.
In addition, since the crank angle positions of the convex portions a, b, c, and d and the crank angle corresponding to the signal period in which they are detected are known, the time-crank angle conversion is performed to determine the crank angle position of each cylinder. It can be detected. If the time of the target ignition timing (for example, the time from the top dead center of each cylinder) is calculated, the ignition timing, the fuel injection timing, etc. can be controlled using the detected signal.
[0038]
Next, FIG. 10 shows a signal form at the time of VVT operation according to the second embodiment of the present invention. This is because the second signal member has four convex portions (four in the same rotation angle position as the convex portions a, b, c, d detected at the top dead center of each cylinder provided in the first signal member. ) (The first signal member is the same as in the first embodiment).
When the VVT is not operated and at the start of advancement immediately after the start of the VVT operation, as shown in FIGS. 10A and 10B, when ignition is performed in order of the cylinders # 1, # 3, # 4, and # 2, The signal form and the signal cycle ratio from the detection of the convex part a by one rotation of the crankshaft to the detection again are the same as in the first embodiment.
[0039]
When the camshaft is advanced to some extent after VVT operation, the signal form and signal cycle ratio are as shown in FIG.
Here, for example, when the VVT conversion angle is n °, as shown in FIG. 11A, the signal periods T1 to T9 measured from the detection of the convex portion a by one rotation of the crankshaft to the detection again. Indicates 10, 170-n, n, 180-n, n, 180-n, n, 180-n, and n (° CA) in order, and the signal cycle ratio is as shown in FIG. Become.
[0040]
As shown in FIG. 11B, by setting an appropriate threshold value, a signal indicating the top dead center of any cylinder is determined from the signal when the signal cycle ratio that has exceeded the threshold value is equal to or less than the threshold value. By comparing the signal cycle ratios exceeding the threshold, it is possible to determine a signal indicating the reference position (the top dead center of the third cylinder) (that is, only one of the signal cycle ratios exceeding the threshold has a value) Different).
[0041]
The operation or non-operation of the VVT can be determined by the number of signals from detection of a signal indicating a reference position to detection again, for example, as in the first embodiment, and each detected signal can be determined.
The VVT conversion angle n is calculated in the same manner as in the first embodiment. For example, it can be calculated as the VVT conversion angle n = 180 × T5 / (T4 + T5) of the fourth cylinder.
[0042]
The detection of the crank angle position, the ignition timing, and the fuel injection timing can also be performed in the same manner as in the first embodiment.
According to this embodiment, since the VVT conversion angle for each cylinder can be detected, the detection accuracy of the VVT conversion angle during the VVT operation is improved, and as a result, the control accuracy (responsiveness, convergence) is improved.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram according to an embodiment of the present invention.
FIG. 2 is also an explanatory diagram of a variable valve timing mechanism.
FIG. 3 is a schematic view of a variable valve timing control device.
FIG. 4 is a schematic view of a first signal member and a second signal member.
FIG. 5 is a diagram showing sensor output at the time of VVT non-operation and operation when a Hall IC is similarly used as an angle sensor.
FIG. 6 is a diagram showing sensor output when VVT is not activated and activated when a magnetic pickup sensor is used as the angle sensor.
FIG. 7 is a view showing VVT non-operation, signal form during operation, and signal cycle ratio according to the first embodiment.
FIG. 8 is a view showing signal forms and signal cycle ratios detected by the ECU when the VVT is operating (n ° CA advance angle) according to the first embodiment.
FIG. 9 is a diagram showing a signal cycle ratio with respect to a VVT conversion angle in the first embodiment.
FIG. 10 is a diagram showing a signal form and a signal cycle ratio when the VVT is operated similarly according to the second embodiment.
FIG. 11 is a diagram showing signal forms and signal cycle ratios detected by the ECU when the VVT is operating (n ° CA advance angle) according to the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine 3 ... Air flow meter 4 ... Throttle valve 6 ... Fuel injection valve 7 ... Spark plug 8 ... Intake valve 9 ... Exhaust valve 11 ... Intake cam shaft 20 ... ECU
22 ... Helical spline 30 ... Variable valve timing mechanism 31 ... First signal member 32 ... Second signal member 33 ... Angle sensor

Claims (7)

An engine control information detection device including a variable valve timing control device that changes a valve timing by changing a rotation phase of a camshaft relative to a crankshaft,
A first signal member mounted to rotate in synchronization with the crankshaft;
A second signal member adjacent to the first signal member, is mounted so as to synchronize with the cam shaft,
One angle sensor that is arranged to face the two signal members and outputs a detection signal each time a detected portion provided on the two signal members passes ;
Is configured to include a,
The first signal member is provided with as many first detected parts as the number of cylinders detected by the angle sensor at a predetermined crank angle position of each cylinder, and is disposed close to the specific first detected part. While providing the second detected portion,
The second signal member is provided with a third detected portion that is detected simultaneously with the first detected portion by the angle sensor when the variable valve timing control device is not operated .
During the operation of the variable valve timing control device, the detection signal of the third detected portion is discriminated from the detection signals output from the angle sensor, and the detection signal of the three detected portions and the detections before and after the detection signal are detected. An engine control information detection device that detects a rotation phase of the cam shaft relative to the crankshaft based on a time interval with each of the signals . A ratio of consecutive time intervals is calculated as a signal cycle ratio, a specific cylinder is determined based on a detection signal when the calculated signal cycle ratio becomes a predetermined value or exceeds a predetermined threshold value, and based on the determination result, The engine control information detection apparatus according to claim 1, wherein a detection signal of the third detected part is determined . Wherein to determine the detection signal of the first detection target portion of the detected signal, the time from the time interval of the detection signal of the first portion to be detected - by the crank angle conversion line Ukoto, the crank angle position in each of the cylinders control information detection apparatus for an engine according to claim 1 or claim 2, wherein the detecting. Said second signal member, wherein the particular first engine according to claims 1 to any one of claims 3, characterized in that a single third detection target portion corresponding to the portion to be detected Control information detection device. Said second signal member, according to claims 1, characterized in that a first fraction third detection target portion cylinders corresponding to each of the detector to any one of claims 3 Engine control information detection device. It said angle sensor is control information detecting apparatus for an engine according to any one of claims 1 to 5, characterized in that a Hall IC. Control information detection apparatus for an engine according to claim 1, any one of claim 5 wherein said angle sensor is a magnetic pickup sensor.

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