JP4081254B2 - Reverse rotation detection control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for an internal combustion engine such as a vehicle, and more particularly to an internal combustion engine control device that performs ignition control, fuel injection control, etc. using a crank angle sensor signal for cylinder discrimination and a crank angle sensor signal for angle detection. The present invention relates to a reverse rotation detection control device that detects reverse rotation.
[0002]
[Prior art]
In recent years, in an internal combustion engine for vehicles, particularly automobiles, an electronic control unit has been adopted in order to cope with stricter exhaust gas regulations while at the same time achieving higher output, fuel injection amount, fuel injection timing and ignition timing. Etc. are precisely controlled to cope with stricter exhaust gas regulations and higher output.
When controlling the fuel injection timing and the ignition timing, it is necessary to determine the crank rotation angle and the cylinder number. Therefore, a rotation angle sensor is provided to know the rotation angle of the crankshaft.
[0003]
Generally, the rotation angle sensor has a configuration in which a crank rotation angle sensor and a cylinder discrimination sensor are provided on a camshaft or the like that rotates synchronously with the crankshaft rotation at 1/2. As a technique for detecting the crank angle and determining the cylinder number using signals from the crank rotation angle sensor and the cylinder discrimination sensor, there is a technique disclosed in Japanese Patent Laid-Open No. 3-229953.
[0004]
In this technology, a light emitting element and a light receiving element for a crank rotation angle sensor for detecting the crankshaft rotation angle every 1 deg of the minimum unit are arranged on one rotating disk, and a signal input corresponding to a specific cylinder is obtained and specified. A light-emitting element and a light-receiving element for cylinder discrimination sensors for discriminating cylinders are arranged and detected by the respective elements, and the optimum fuel injection timing and ignition timing for each cylinder are controlled in units of crank shaft rotation angle 1 deg. To do.
[0005]
Examples of other techniques for detecting the crank angle and determining the cylinder number based on signals from the crank rotation angle sensor and the cylinder discrimination sensor are described in JP-A-5-231294 and JP-A-5-312088. Although there are technologies, the two input signal methods of the reference signal and the cylinder identification signal provided separately from the reference signal both increase the number of sensors and increase the cost. Cylinder determination is performed by simultaneously referring to the plurality of sensors.
[0006]
As described above, the means for determining the crank angle and the cylinder number by using separate sensors increases the number of sensors and causes an increase in cost, and a control system for operating based on detection of the plurality of sensors. Have problems such as becoming complicated. Japanese Patent Laid-Open No. 5-86953 or Japanese Patent Publication No. 5-86953 discloses a technique for detecting a crank rotation angle and determining a cylinder number based on a signal from the rotation angle sensor as a means for solving the problem. 7-58058.
[0007]
In the disclosed technique, one cylinder determination pulse signal output means is provided immediately after the end of one reference pulse signal among several reference pulse signals set corresponding to each cylinder of the crank rotation angle sensor. Separately provided, the cycle time is measured for each input of the sensor signal, the ratio of the previous and current pulse intervals (cycle time) is calculated, and compared with a predetermined determination value, which is a reference pulse signal or cylinder It is determined whether the pulse signal is for determination.
[0008]
By the way, in the prior art using the disclosed single rotation angle sensor, when the internal combustion engine rotates in the reverse direction, the reverse rotation cannot be detected, and the sensor signal is input based on the input signal. Although fuel injection and ignition control control are performed, the number of input signals is small, so that there are problems in the fuel injection timing and ignition timing control.
[0009]
That is, in the case of a 4-cylinder engine, there are 1 to 3 signals for every 180 degrees of crankshaft rotation, so the time for inputting these signals is measured and divided by the preset angle values of these signals. Thus, the time per unit rotation angle is calculated, and the fuel injection or ignition control is performed when the time corresponding to the angle is reached with respect to the operating angle control value of the fuel injection timing or ignition timing. Has been done.
[0010]
However, in this time control method, since the time of signal input time measurement is different from the time of fuel injection control timing and ignition control operation, if there is a fluctuation in the rotation of the crankshaft of the internal combustion engine, the fuel injection Phenomena occur such that the timing and ignition timing become earlier or later than the set value.
[0011]
For example, when the rotation of the internal combustion engine is 800 rpm and there is a steady rotation fluctuation of ± 100 rpm, the ignition timing causes an error in the advance direction by about 2 deg from the set value, while in the case of sudden acceleration, the retard direction In the case of sudden deceleration, the error in the advance angle direction. If the ignition timing is shifted, knocking may occur, which may hinder smooth operation of the internal combustion engine.
[0012]
Further, when fuel injection and ignition control are performed due to an erroneous determination and the internal combustion engine rotates in the reverse direction, the reverse rotation cannot be detected. For this reason, a driver or operator who noticed an abnormality had to stop the internal combustion engine and stop the internal combustion engine.
[0013]
As described above, in an internal combustion engine for automobiles, it is desired to increase the output. For this reason, in order to enable high-speed rotation of the internal combustion engine, there is an overlap in the opening and closing timing of the intake and exhaust valves of the internal combustion engine. Since the period tends to increase and the ignition timing is set to the more advanced side, the reverse rotation of the internal combustion engine is likely to occur, thereby preventing control due to erroneous determination or erroneous detection. It became more demanded.
[0014]
[Problems to be solved by the invention]
As described above, in the conventional electronic control unit for an internal combustion engine, when the reverse rotation of the engine occurs, the rotation direction of the engine cannot be recognized, and thus there is a possibility of erroneous power distribution that causes ignition to an abnormal cylinder. .
Further, the reverse rotation when the internal combustion engine is stopped is not taken into consideration, and there is a possibility that the internal combustion engine is damaged or the startability is deteriorated during the reverse rotation.
An object of the present invention is to protect an internal combustion engine and improve startability by detecting reverse rotation of the internal combustion engine.
[0015]
The present invention has been made in view of the above-described problems, and an object of the present invention is to detect the reverse rotation of the internal combustion engine, thereby preventing misignition of the ignition signal, protecting the internal combustion engine, and starting the engine. An object of the present invention is to provide a reverse rotation detection control device for an internal combustion engine that can improve the performance.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the reverse rotation detection control device of the present invention basically includes a cylinder discrimination crank angle sensor signal input means for inputting a cylinder discrimination crank angle sensor signal, and an angle detection crank angle sensor signal. Crank angle sensor signal input means for inputting angle, and reverse rotation detection means for detecting reverse rotation of the internal combustion engine based on the cylinder discrimination crank angle sensor signal and the angle detection crank angle sensor signal. It is characterized by.
[0017]
Further, the reverse rotation detection control device of the present invention includes a cylinder discrimination crank angle sensor signal input means for inputting a cylinder discrimination crank angle sensor signal, and an angle detection crank angle sensor signal for inputting an angle detection crank angle sensor signal. The cylinder number is updated based on the input means, the cylinder discrimination means for discriminating the cylinder based on the cylinder discrimination crank angle sensor signal and the angle detection crank angle sensor signal, and the cylinder discrimination crank angle sensor signal based on the cylinder discrimination crank angle sensor signal. Reverse rotation detection for determining a specific cylinder and comparing the determined specific cylinder signal with the specific cylinder signal output from the cylinder determining means and detecting reverse rotation of the internal combustion engine when the comparison result is inconsistent Means.
[0018]
Further, the specific aspect of the reverse rotation detection control device of the present invention is characterized in that the reverse rotation detection means discriminates based on the specific cylinder signal output from the cylinder discrimination means and the cylinder discrimination crank angle sensor signal. The comparison with the cylinder signal is performed at each ignition output timing.
[0019]
More preferably, the specific cylinder may be a first cylinder.
Further, a specific aspect of the reverse rotation detection control device of the present invention further includes a control means for prohibiting output of an ignition output signal for each cylinder when the reverse rotation detection means detects reverse rotation of the internal combustion engine. It is characterized by providing.
With the reverse rotation detection control device of the present invention configured as described above, it is possible to detect reverse rotation of the internal combustion engine, and it is possible to protect the internal combustion engine by preventing erroneous ignition of the ignition signal.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the reverse rotation detection control device of the present invention will be described in detail with reference to the drawings.
[0021]
FIG. 1 is a diagram illustrating a configuration of the reverse rotation detection control device of the present embodiment. FIG. 1 shows a circuit of a 6-cylinder engine.
In FIG. 1, the reverse rotation detection control device is an AND circuit 1 (input of cylinder discrimination crank angle sensor signal) that takes an AND logic of a cylinder discrimination crank angle sensor signal A and an angle detection crank angle sensor signal B (1 ° signal). Means, an angle detection crank angle sensor signal input means), a cylinder discrimination circuit 2 (cylinder discrimination means) for discriminating a cylinder from the output signal C of the AND circuit 1, and a signal output from the cylinder discrimination circuit 2 for each cylinder. The microcomputer 4 includes a CY1 to CY6, a 2-input AND circuit 3 that takes an AND logic of the ignition signal D for each cylinder output from the microcomputer 4 (reverse rotation detecting means), and the microcomputer 4.
[0022]
The microcomputer 4 updates the cylinder number based on the cylinder discrimination crank angle sensor signal A to discriminate the first cylinder, and the discriminated first cylinder signal and the first cylinder signal output from the cylinder discrimination circuit 2. When the comparison result is inconsistent, reverse rotation of the internal combustion engine is detected. The microcomputer 4 outputs a cylinder discrimination circuit reset signal F that clears the cylinder discrimination circuit 2 when detecting reverse rotation of the internal combustion engine.
The cylinder discriminating circuit 2 determines that the cylinder is a specific cylinder when the crank discriminating crank angle sensor signal A reaches a predetermined count value by counting the angle detecting crank angle sensor signal B while the cylinder discriminating crank angle sensor signal A is HIGH. Detect.
[0023]
The 2-input AND circuit 3 takes the AND logic of the cylinder discrimination signals CY1 to CY6 from the cylinder discrimination circuit 2 and the ignition signal D output for each cylinder from the microcomputer 4 as ignition output signals I1 to I6 for each cylinder. Distributed.
The two-input AND circuit 3 and the microcomputer 4 as a whole have a function as control means for prohibiting the output of the ignition output signal for each cylinder when the reverse rotation of the internal combustion engine is detected.
Hereinafter, the operation of the reverse rotation detection control apparatus configured as described above will be described.
[0024]
FIG. 2 is a flowchart showing an operation for detecting whether the engine is rotating forward or backward, and is interrupted by the microcomputer 4 during ignition control. In the figure, S indicates each step of the flow.
FIG. 3 is a timing chart of each signal at the time of reverse rotation for explaining the operation of the present embodiment.
[0025]
First, in step S1, the first cylinder signal CY1 output from the cylinder discriminating circuit 2 is detected by an ignition interruption, and if the first cylinder signal CY1 is not being output, this flow is ended because the condition is not met.
If the first cylinder signal CY1 is being output, it is determined in step S2 whether the cylinder determination counter value G shown in FIG. 3 is $ FF or $ 00. If the cylinder discrimination counter value G is other than $ FF or $ 00, each cylinder output from the cylinder discrimination circuit 2 depends on whether the reverse rotation determination flag E is “1” (# E = “1”) in step S3. Comparison with the cylinder discrimination signals CY1 to CY6 is performed. When the reverse rotation determination flag E is not “1”, it is recognized that the comparison result does not coincide with the value at the time of forward rotation, and it is recognized that the internal combustion engine is reverse rotation. In step S4, the reverse rotation determination flag E Is set to “1” (# E ← “1”).
[0026]
When the reverse rotation determination flag E becomes “1”, the cylinder determination circuit reset signal F is set to “LOW” until the next cylinder determination crank angle sensor signal A is received in step S5 (F = “0” ← “1”). ) In step S6, the cylinder discrimination circuit 2 is cleared (G ← $ 00), and this flow is finished.
[0027]
If the cylinder discrimination counter value G is $ FF or $ 00 in step S2, or if the reverse rotation determination flag E is "1" in step S3, the process skips steps S4 and S5 and proceeds to step S6.
Thus, by resetting the cylinder discrimination circuit 2, all the cylinder discrimination signals CY1 to CY6 output from the cylinder discrimination circuit 2 at the time of reverse rotation of the internal combustion engine are set to “LOW”, and the ignition output to each cylinder is set. By prohibiting it, misfires are prevented.
[0028]
By executing the above flow, as shown in FIG. 3, when the internal combustion engine rotates in the reverse direction, the first cylinder signal # 1 of the cylinder discrimination crank angle sensor signal A is input to the control device twice in succession. In this state, the one-cylinder discrimination signal CY1 output from the cylinder discrimination circuit 2 is continuously output twice.
[0029]
On the other hand, the cylinder discriminating logic in the microcomputer 4 updates the cylinder number every time the cylinder discriminating crank angle sensor signal A is inputted after the one-cylinder discriminating signal CY1 is inputted. The cylinder discrimination counter value G calculated in the microcomputer 4 is compared with the one cylinder discrimination signal CY1 output from the cylinder discrimination circuit 2, and when it is recognized that there is a mismatch, the cylinder discrimination counter value G is cleared. By setting the rotation determination flag to “1” and simultaneously setting the reset signal F of the cylinder determination counter 2 to “LOW”, erroneous ignition is prevented.
[0030]
As described above in detail, the reverse rotation detection control device of the present embodiment includes an AND circuit 1 that takes an AND logic of the cylinder discrimination crank angle sensor signal A and the angle detection crank angle sensor signal B (1 ° signal). The cylinder discriminating circuit 2 discriminates the cylinder from the output signal C of the AND circuit 1, the signals CY1 to CY6 outputted from the cylinder discriminating circuit 2 for each cylinder, and the ignition signal D for each cylinder outputted from the microcomputer 4. And a microcomputer 4, which updates the cylinder number based on the cylinder discrimination crank angle sensor signal A and discriminates the first cylinder. The discriminated 1st cylinder signal is compared with the 1st cylinder signal output from the cylinder discriminating circuit 2, and when the comparison result is inconsistent, the reverse rotation of the internal combustion engine is detected. It is possible to detect the forward rotation / reverse rotation of the engine of the engine. As a result, normal ignition can be performed during normal engine rotation, and ignition can be stopped during reverse engine rotation. This prevents the engine from being damaged regardless of whether the engine is normal or reverse engine rotation. There is. Moreover, the startability after reverse rotation can be improved.
[0031]
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various changes in design can be made without departing from the spirit of the invention described in the claims. It is something that can be done.
[0032]
【The invention's effect】
As can be understood from the above description, the reverse rotation detection control device according to the present invention can detect the reverse rotation of the internal combustion engine, prevents erroneous ignition of the ignition signal, protects the internal combustion engine, and starts. Can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a reverse rotation detection control apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing an operation of detecting whether the engine of the reverse rotation detection control device of the present embodiment is normal rotation or reverse rotation.
FIG. 3 is a timing chart of signals at the time of reverse rotation of the reverse rotation detection control device of the present embodiment.
[Explanation of symbols]
1. AND circuit (crank angle sensor signal input means for cylinder discrimination, crank angle sensor signal input means for angle detection)
2. Cylinder discrimination circuit (cylinder discrimination means)
3 ... 2-input AND circuit (part of control means)
4 ... Microcomputer (reverse rotation detection means, part of control means)
A ... Crank angle sensor signal for cylinder discrimination B ... Crank angle sensor signal for angle detection (1 ° signal)
C ... Output signal D of 2-input AND circuit 1 ... Ignition signal E output from microcomputer ... Reverse rotation determination flag F ... Cylinder discrimination circuit reset signal G ... Cylinder discrimination counter value CY1 ... One cylinder discrimination signal CY2 ... Two cylinder discrimination Signal CY3 ... Three cylinder discrimination signal CY4 ... Four cylinder discrimination signal CY5 ... Five cylinder discrimination signal CY6 ... Six cylinder discrimination signal I1 ... One cylinder ignition output signal I2 ... Two cylinder ignition output signal I3 ... Three cylinder ignition output signal I4 ... Four cylinders Ignition output signal I5 ... Five cylinder ignition output signal I6 ... Six cylinder ignition output signal

Claims (4)

Cylinder discrimination crank angle sensor signal input means for inputting a cylinder discrimination crank angle sensor signal;
A crank angle sensor signal input means for angle detection for inputting a crank angle sensor signal for angle detection;
Cylinder discrimination means for discriminating a cylinder based on the crank angle sensor signal for cylinder discrimination and the crank angle sensor signal for angle detection and outputting a specific cylinder signal ;
The cylinder number is updated based on the cylinder discrimination crank angle sensor signal to discriminate a specific cylinder and output a specific cylinder signal. The output specific cylinder signal and the specific cylinder signal output from the cylinder discrimination means And a reverse rotation detecting means for detecting reverse rotation of the internal combustion engine when the comparison result is inconsistent,
When the reverse rotation is detected, the reverse rotation detection means raises a reverse rotation determination flag and resets the cylinder determination means, thereby prohibiting the ignition output to the specific cylinder,
After prohibiting the ignition output, the determined specific cylinder signal is compared with the specific cylinder number output from the cylinder determining means, and when the comparison result matches, the reverse rotation determination flag is lowered, and the specific cylinder A reverse rotation detection control device characterized by starting an ignition output to the motor.   The reverse rotation detecting means compares the specific cylinder signal output from the cylinder determining means with the specific cylinder signal determined based on the cylinder determining crank angle sensor signal at each ignition output timing. The reverse rotation detection control device according to claim 1.   2. The reverse rotation detection control device according to claim 1, wherein the specific cylinder is a first cylinder.   2. The reverse rotation detection control apparatus according to claim 1, further comprising control means for prohibiting output of an ignition output signal for each cylinder when the reverse rotation detection means detects reverse rotation of the internal combustion engine. .

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