JP2575606B2 - Method of indicating and storing an abnormality of a signal generator of an internal combustion engine - Google Patents

Description

The present invention relates to a method for indicating and storing an abnormality of a signal generator of an internal combustion engine, and more particularly to a method for generating at least one reference signal per revolution, which is coupled to a shaft. A first signal generator,
The present invention relates to a method of displaying and storing an abnormality of a signal generator of an internal combustion engine including a second signal generator for generating a signal having a predetermined relationship with a signal from the first signal generator.

B) Prior art In particular, in the case of a five-cylinder internal combustion engine, in order to control electronic ignition, a phase signal must be further extracted in addition to a reference signal obtained from a crankshaft to identify a cylinder. The phase signal generator is coupled to the camshaft and is usually located on the ignition distributor, inductive,
It is formed as an optical or Hall sensor. In addition to this sensor, a speed sensor is used, the speed signal being generated via a gearwheel connected to the crankshaft.
Such complex sensor devices are used, for example, in fuel injection devices and other control devices.

In such an apparatus, when an abnormality occurs, it is often difficult to find out which abnormality is caused by which signal generator. Correct detection of an abnormality often eliminates the need to replace unnecessary sensors, repair unnecessary signal lines, or replace control devices. The crankshaft and the camshaft of the internal combustion engine are connected in a predetermined relationship, the rotation of each shaft is synchronized, and the ignition timing or the injection timing can be determined in relation to a reference signal from the crankshaft.
However, there is a case where the relationship between the phase signal and the reference signal is shifted due to a change with time or a looseness of the sensor attachment. The causes may be various causes such as a shift due to aging, a loose contact in the phase signal generator and the reference signal generator, and a rotational shift of the distributor.

German Offenlegungsschrift 32 04 003 discloses a device for storing and displaying various abnormalities of sensors or switching devices in motor vehicles. The disadvantage is that only anomalies are displayed by comparing the element in this case with its limit values, and it is not possible to detect the cause of the anomalies caused by many of the various components (for example, sensor devices, especially pulse generators). There is.

(C) Objective The present invention has been made to solve such a conventional disadvantage, and a signal generator for an internal combustion engine capable of detecting and displaying an abnormality and pursuing the cause thereof. It is an object of the present invention to provide a method for displaying and storing abnormalities.

D) Examples The present invention will be described in detail below based on examples shown in the drawings.

In the embodiment shown in FIG. 1, what is designated by the reference numeral 10 is a control device formed as a microcomputer, by means of which the ignition and injection stage 11 is controlled. The control device 10 includes a speed signal n from a speed signal generator 12, a crankshaft, and thus a reference signal r obtained from a reference signal generator 13 coupled to the speed signal generator 12, and an internal combustion engine. A phase signal p obtained from a phase signal generator 14 coupled to the camshaft is input. These signal generators
It is formed as an inductive sensor, an optical sensor or a Hall sensor. The control device 10 has not only a function of controlling ignition or fuel injection but also a function of diagnosing the signal generators 12, 13, and 14. The results of the diagnosis or test are respectively stored in the memory of the microcomputer and can be checked immediately or later at the factory via the display device 15. Display device 15
Is composed of a check clamp capable of displaying various abnormalities, a display capable of individually displaying abnormalities, a measuring instrument, or various devices capable of distinguishing various abnormalities. The method of storing the abnormal signal and the display of the abnormal signal are described in detail in the above-mentioned German Patent Publication and will not be described here.

FIG. 2 shows the mutual positional relationship of various signals obtained from the signal generator. In that case, the revolution signal generator 12 generates a number of revolution signals n, for example 135 signals, per revolution of the crankshaft. On the other hand, since the reference signal generator 13 generates one reference signal r per one revolution of the crankshaft, the interval between the two reference signals corresponds to 2Z rotation speed signals. Similarly, since the phase signal generator coupled to the camshaft generates a phase signal p for each rotation of the camshaft, this phase signal p is generated once every two rotations of the crankshaft, If this is the case, the phase signal must match the reference signal r. In that case, the phase signal has a signal width Zp. This phase signal generator, usually located in the distributor, is what is needed to identify a cylinder in a five cylinder engine.

By logically combining these three signals n, r, p with each other, it is not only the presence or absence of these pulses or pulse trains, but also the correct position of the signals r, p with respect to each other and therefore the distributor. It is possible to detect and display whether the adjustment has been made. Further, it is also possible to detect and display a loose contact with the lead wire in addition to the static abnormality of each pulse train. The test by the logical connection is performed by a microcomputer in a control device having a diagnostic program. In this case, this diagnostic program is executed before the original control (ignition, injection). The diagnostic programs or tests and the main programs such as ignition injection can be combined with each other, or the diagnostic programs can be periodically executed between the main programs.

FIG. 3 illustrates the sequence of the tests in the form of a flow chart, where the key criteria are many causes for certain anomalies in the temporal flow of the signal, and therefore the anomalies are uniquely defined. The abnormality is stored and displayed only when the signal can be related to the signal or a predetermined cause.

First, the microcomputer 10 starts at step 20 and then initializes at step 21, all abnormalities are erased (reset), and all registers, flip-flops and counters are reset. Thereafter, first, at step 22, an abnormal signal is set for the rotational speed. This abnormal signal of the rotational speed is shown as n abnormal (1), and the n abnormal (1) is detected in step 23 at the end of the rotational speed signal n (at the rising end of the rotational speed signal,
Depending on the design, it may be the falling edge of the signal. In the following embodiments, the end of the rotation speed signal means a rising end. ) Is obtained and then erased (step 24). If the n signal does not appear and the speed signal is abnormal, it is checked in step 68 which will be described in more detail in FIG.

After the n anomaly (1) has been eliminated (step 24), at step 25, the rotational speed signal counter (n counter) in the microcomputer 10 is set to a value of 0 to check the phase signal. This counter (which requires four more) can be realized by a separate circuit, but in this embodiment, it is realized by a register of a microcomputer.
The addition in the counting of the counter is performed by using the accumulator. In any case, the result is stored in the memory. In the next step 26, the content of the n counter is incremented by one. Thereafter, at step 27, it is determined whether or not the end of the phase signal p (falling end of the phase signal; hereinafter, the end of the phase signal means the falling end) has appeared. If the end of the p signal does not appear,
It is checked whether a value larger than 4Z + K exists in the n counter (step 28). In this case, 4Z corresponds to four rotations of the crankshaft. That is, two phase signals appear within this interval. In that case, an allowable range is first provided for the inspection of whether the p signal is abnormal. When such an allowable range is not provided, 2Z is used instead of 4Z.
Here, K is an allowable coefficient. If this condition is not satisfied in step 28, the content of the n counter is incremented by 1 in step 26. This loop is repeated until the value reaches 4Z + K unless the end of the p signal appears. 4Z +
When the temperature reaches K, the phase signal is abnormal, and the p abnormality (1) is stored and displayed (step 29). Thus, the n counter detects whether or not the phase signal p appears,
4Z + K (Z is the interval between two reference signals, Z is 135
If 540 + K) number of rotation signals are counted, it is determined that no phase signal appears and p
Abnormality (1) is stored. This abnormal signal is determined to be a defect in the phase signal generator 14 or a disconnection or short circuit of the lead wire. In such a case, control of ignition or injection becomes impossible.

On the other hand, when the end of the p signal appears in step 27, whether or not the phase signal has a value of 0 in step 30, that is, whether or not the start of the phase signal has been reached (the phase signal is a 0 signal) Is determined. Subsequently, it is checked whether the reference signal r exists. To do so, the n counter is set to 0 in step 31 and then +1 is performed in step 32. In step 33, the reference signal r
Is determined. If there is no reference signal r, the n counter is incremented by +1 at step 32, which means that the phase signal is present at step 34 (p =
0). Since the start of the phase signal (p = 0) is detected in step 30 and the n counter is set to 0 in step 31, the loop of steps 32-34 continues until the reference signal appears in step 33. The interval from the start of the phase signal to the appearance of the reference signal can be known. Here, it is assumed that the reference signal r appears normally between the phase signals (step 33).

Subsequently, loose contact with the phase signal (p abnormality (2))
Is checked to see if it exists. For this reason, the signal from the phase signal generator 14 becomes 1 as usual at the time of the next reference signal r.
, That is, whether the value of the phase signal is not zero. For this purpose, first in step 35 the n counter is set to zero. Then, at step 36, the n counter is incremented by one. This is because the counter determines in step 37 the correction factor K from the distance between the two reference signals r.
Is performed until Z-K corresponding to the value obtained by subtracting is obtained. If this value is exceeded in step 37, it is determined in step 38 whether or not the reference signal r has appeared. This is done by repeating loops 36-39, each time in step 36 the n counter is correspondingly incremented and the value Z +
It is performed until K is exceeded. As described above, in steps 36 to 39, the n counter measures the interval from the appearance of the reference signal to the appearance of the next reference signal. In steps 36 to 39, the loop is repeated until the next reference signal appears between the value of the n counter between "ZK" and "Z + K".
As a result, it is detected whether or not the next reference signal appears in the range of the value obtained by adding or subtracting the allowable coefficient K to the crankshaft one rotation cycle (Z). If the reference signal r does not appear between Z-K and Z + K, then there is an anomaly that cannot be examined in this test step (i.e., there is no reference signal or the rotational speed signal is lost due to loose contact). It cannot be unambiguously determined whether it is missing). The test then returns to step 24 and continues. On the other hand, if the reference signal r appears during this time interval (step 38), at the same time in step 40 the phase signal generator 14
Is checked. If this signal level is equal to 1 as normal, the main program (not shown) is started and ignition, injection or other control is started. On the other hand, if the signal level is 0, an abnormal signal is generated in the phase signal in step 41 (p abnormal (2)), thereby indicating that the phase signal is defective. This is an abnormality that is often caused by loose contact.

Returning to loops 32 to 34 again, step 34
At the end of the phase signal, if the reference signal r does not appear, it is checked whether the reference signal is abnormal. To do so, +1 is performed on the n counter having the current Zp as shown in step 42. Subsequently, at step 43, it is checked again whether or not the reference signal r has been generated. In this case, the loop of steps 42 to 44 is performed until the value of the counter reaches 2Z + Zp (step 44). The value of 2Z + Zp corresponds to a value obtained by adding the count value Zp corresponding to the signal width of the phase signal to twice the distance between the two reference signals. In this case, an allowable range is provided for the abnormality of the reference signal.
If such an allowance is not found, the loop is repeated until the value of 2Z + Zp is reached in loops 42-44. Therefore, in the loop of steps 42 to 44, the n counter counts the number of rotations after the phase signal becomes high level (p = 1) and determines whether a reference signal has appeared during a period 2Z corresponding to two rotations of the crankshaft. Used to determine When the n counter reaches this value, it is stored in step 45 that there is an abnormality with respect to the reference signal, and similarly in the case of the abnormal signal generator, an abnormality of the phase angle (α abnormality) is stored in step 46. If so, delete (reset) it. This will be described later in detail.

On the other hand, if the reference signal r is obtained in step 43 in the course of the loops 42 to 44, it is determined whether there is an abnormality (shift) in the phase angle, that is, the reference signal is incorrectly shifted in phase angle with respect to the phase signal. It is checked whether it is. This abnormality is based on, for example, a rotational deviation of the distributor. First, in step 47, the other rotation speed signal counter (n1 counter) is set to zero. Then step 48
It is determined whether or not the first n counter has exceeded the value of Zp (corresponding to the period of the phase signal p = 0). Since the n counter has already counted the value of Zp at the time of the previous phase signal, the process proceeds to step 49, but if the value is smaller than that value, another abnormality exists and the process returns to step 24. The test is performed again. On the other hand, if the value of Zp is exceeded in step 48, it is determined in step 49 whether the reference signal r is present. This is done through loops 49-51, during which step 50 n1
The counter is incremented by one, which means that the count value is 2Z + K
(Z is the interval between the reference signals, K is the allowable coefficient) (Step 51). If the value exceeds 2Z + K, it means that the reference signal is abnormal,
Stored at 45. Thus, the n1 counter is n
The counter counts the number of revolutions signals in the same manner as the counter, and detects an interval from the time when the phase signal p becomes a high level to the time when the reference signal appears next time. On the other hand, when the reference signal r appears between the loops 49 to 51 (step 49), it is determined whether or not this reference signal keeps a correct distance from the previous one (step 52). The correct distance is Z, in which case a tolerance of at least ± 1 is provided. If the distance is incorrect, another anomaly is present and the
Return to 24 and test again. On the other hand, if the distance is correct, the phase signal p
It is checked whether = 0 exists. Since the previous reference signal (step 43) does not match the phase signal, the phase signal will be present if the function is normal. Therefore, if there is no phase signal in step 53, the phase angle abnormality (α abnormality) is stored and displayed similarly (step 54). This is due to the angular shift between the reference signal and the phase signal, which is mainly due to the shift of the distributor.

FIG. 4 shows a control flow (68) for knowing the abnormality of the rotational speed signal schematically shown in FIG. The purpose is to store other rotational speed abnormalities (n abnormalities (2)). After power-on, phase signal p and reference signal r as normal
Is generated, but the rotation speed signal n may not be generated.
In such a case, the rotation speed abnormality (n abnormality (2)) is stored. Even if a rotation speed signal is obtained later, the storage is not erased and stored, so that it is prepared for a later inspection.

When the power is turned on, there may be a case where chattering and other noises are mistaken for the reference signal and the phase signal, and furthermore, at this time, the rotation speed signal may not be generated. In that case, the abnormality of the rotation speed is detected by the above description, but this is not the actual rotation speed abnormality. On the other hand, two of the normal reference signal and the phase signal
If a rotation speed signal is obtained only after three cycles, there is an abnormality in the rotation speed. This abnormality appears to have been resolved by the rotation speed signal appearing later, but basically there is an abnormality in the rotation speed signal generator and must be investigated later.

Therefore, in the present invention, it is checked whether or not several reference signals and phase signals are generated in a normal order, and if they are generated, it is sure that the reference signals and phase signals are not the reference signals and phase signals due to chattering and other noises. Therefore, if no rotation speed signal is generated at that time, the abnormality of the rotation speed is stored. As described above, this memory is not erased even if a rotation speed signal appears later, and its cause is investigated later.

If the end of the rotational speed signal does not appear in step 23, it is checked in step 55 whether the end of the phase signal has appeared, and in step 56 it is checked whether that end is the beginning of the phase signal.

Thereafter, a phase signal counter (p counter) for counting the number of appearances of the phase signal is incremented by 1 (step 57). Then, in step 58, the state of the phase signal generator 14 is checked. At that time, the signal level becomes 0. I have. Thereafter, it is checked whether or not the reference signal r has been generated through the loops 59 to 63 and 58 (step 59). When the end of the rotation speed signal appears in this loop (step 62), the abnormality of the rotation speed signal is not stored, and the process returns to step 24 in the manner described above, and the rotation speed abnormality signal (n abnormality (1 )) Is reset again. In step 59, the reference signal r
Appears, the first reference signal counter (r (p = 0) counter), which counts only when p = 0, is incremented by 1 (step 64). When the phase signal ends in the above-mentioned loop (58 to 63) (step 58), it is checked in step 65 whether or not the reference signal r appears. This loop consists of steps 60-63,58,65. Here, when the reference signal appears, the second reference signal counter (r (p = 1) counter) which performs counting only when p = 1 in step 66 is incremented by one. If the phase signal is normal in this way, p = 0 and 1 are alternately determined in step 63, so that both loops are branched alternately. In step 60, this is a predetermined condition, that is, the first reference. The signal counter (r (p
= 0) counter has a value of 2, the second reference signal counter (r (p = 1) counter) has a value of 1, and the phase signal counter (p counter) has a value of 3. Until it continues. In this case, in this loop, whenever the end of the p signal appears at step 63, the p counter is incremented by 1 (step 57). On the other hand, if the predetermined condition is satisfied in step 60 (this is because the signals of p and r are not shown in FIG. 2).
(Meaning that they appeared in the normal order at the time of 1), and the abnormal signal (2) of the rotational speed is stored (step 67). This is because even if the rotational speed signal is detected in step 62,
Unlike the phase signal (1) of the rotation speed, it is not erased in step 24. This means that the speed signal has irregularities after the control device 10 has been activated, or that the speed signal has been missing for a predetermined time due to loose contact when the engine is running. . On the other hand, if the p and r signals do not appear in the predetermined order as shown in FIG. 4, it is determined that the signals are noise or chattering signals, and the abnormal rotation speed signal (2) is not formed and the step is not performed. At 23 it is checked whether the end of the speed signal appears. In this way, it is checked in FIG. 4 whether the phase signal p and the reference signal r have been generated in the normal order, and if they are detected in step 60, the reference signal and the noise due to chattering and other noises are detected. Since it is certain that the signal is not a phase signal, if no rotation speed signal is generated at that time, an abnormality of the rotation speed (n abnormality (2)) is stored in step 67.

In the embodiment described above, the signal generators 13 and 14 may generate not only one signal but also a plurality of signals per rotation. This depends, in particular, on the four-cylinder internal combustion engine, whether the other required signals must be generated electronically internally. Furthermore, the control device 10 can be supplied with further parameters necessary for forming the control signal. This is the arrow
This is shown in PM.

As described above, according to the present invention, when an abnormality occurring in the signal generator of the internal combustion engine is detected, not only this is displayed but also the cause thereof is pursued. That is, the abnormality is shown in more detail only when the cause can be pursued. That is, when the various signal generators are acting alternately, an abnormality of the signal generator causing the abnormality is indicated. In this way, loose contacts of the signal generator, abnormalities in the phase angle, and the like can be identified in addition to the overall defects such as short circuit and disconnection. By reading out the abnormality stored in the factory later, the advantage is obtained that the abnormality can be easily overcome and the parts need not be replaced unnecessarily.

E) Effect As described above, in the present invention, based on the high-frequency rotation speed signal obtained with the rotation of the shaft, the reference signal obtained every rotation of the shaft and the reference signal have a fixed relationship. Since the order and interval with other signals are detected,
An excellent effect is obtained in that a deviation from a predetermined order and a predetermined interval can be accurately detected, and an abnormality can be easily overcome.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a basic configuration of a control device including various signal generators according to the present invention, FIG. 2 is a signal waveform diagram showing a normal signal sequence obtained from the signal generator, FIG. 3 and FIG. 4 are flow charts showing a control flow for testing an abnormality of the signal generator. 10 ... Control device, 11 ... Ignition and injection stage 12 ... Rotation speed signal generator, 13 ... Reference signal generator 14 ... Phase signal generator, 15 ... Display device

Continued on the front page (72) Inventor Guyenter Kaiser 7000 Stuttgart, Germany 40 Schwainfursstraße 10 (72) Inventor Wolfgang Grozsel 7000 Stuttgart, Germany 1 Schwabstrasse 70 Be (56) Reference Document JP-A-55-142233 (JP, A) JP-A-56-141534 (JP, A) JP-A-53-24907 (JP, A) JP-A-54-10810 (JP, A) 46563 (JP, B2)

Claims (14)

(57) [Claims] 1. A method for indicating and storing an abnormality of a signal generator of an internal combustion engine, comprising a first signal generator (13) coupled to a shaft and at least one reference signal (r) per revolution. )
Is generated, and another signal (p) having a fixed relationship with the signal of the first signal generator (13) is generated by the second signal generator (14). A deviation of the other signal (p) from the predetermined order and a deviation from the predetermined interval are detected, and based on the deviation, at least one abnormal signal is generated, the abnormal signal is stored, and the abnormal signal is stored in the display device (15). A method for displaying and storing an abnormality of a signal generator of an internal combustion engine to be supplied, wherein a high frequency rotation speed signal (n) indicating a rotation speed of the shaft is generated by a rotation speed sensor (12); The order and interval of the reference signal (r) and the other signal (p) are detected based on (n), and if a deviation from the predetermined order and the predetermined interval is detected, an abnormal signal is generated. Displays abnormalities of the signal generator of the internal combustion engine , Method of storing. 2. The signal generator according to claim 1, wherein the first signal generator is coupled to a crankshaft of the internal combustion engine, and the second signal generator is coupled to the camshaft to generate a phase signal. A method for displaying and storing an abnormality in a signal generator of an internal combustion engine according to claim 1. 3. An n-th reference signal is generated between phase signals whose period is longer than that of the reference signal, and when the coincidence between the phase signal and this reference signal deviates beyond a predetermined allowable range, an abnormality occurs. 3. A method for displaying and storing an abnormality of a signal generator of an internal combustion engine according to claim 2, wherein the signal is generated. 4. The method according to claim 1, wherein a signal interval between the two signals is counted using the rotation speed signal (n), and an abnormal signal is generated when the signal interval exceeds a predetermined count value. A method for displaying and storing an abnormality of the signal generator for an internal combustion engine according to any one of the preceding claims. 5. In order to check a phase signal which is not generated at the time of the next reference signal after the phase signal (p) and the reference signal (r) coincide with each other, a rotation speed signal (n 5. The signal generator for an internal combustion engine according to claim 4, wherein an abnormal phase signal is generated when a phase signal is generated simultaneously with the next reference signal. How to display and store abnormalities. 6. A rotation speed signal (n) is counted from a first signal end of the phase signal (p), and the reference signal (r) is converted before reaching a numerical value (Zp) corresponding to the length of the phase signal. The abnormality signal is not generated, and the process proceeds to the next inspection step, and the abnormality of the signal generator of the internal combustion engine according to claim 3, 4, or 5 is displayed. How to remember. 7. An abnormal signal is generated for a reference signal when the reference signal reaches a predetermined numerical value corresponding to a signal interval (Z) between two reference signals (r) without appearing. 7. A method for displaying and storing an abnormality of a signal generator of an internal combustion engine according to claim 6. 8. When a reference signal is generated before a predetermined numerical value is reached, counting of a rotation speed signal is further started, and when a numerical value corresponding to a signal interval between the reference signals is reached without a next reference signal appearing. 8. A method according to claim 7, wherein an abnormal signal is generated in response to a reference signal. 9. An abnormal signal of a phase angle when a reference signal is generated at a predetermined interval during the counting and a phase signal is absent at the same time. A method for displaying and storing an abnormality of the signal generator of the internal combustion engine according to the paragraph. 10. A method according to claim 1, wherein when the test is started, a rotational speed abnormal signal is formed, and when an end of the rotational speed signal appears, the signal is reset. A method for displaying and storing an abnormality of the signal generator of an internal combustion engine according to claim 1. 11. When the phase signal and the reference signal are generated and the rotational speed signal is absent, it is checked whether the order of the phase signal and the reference signal is in a predetermined order. 11. The method for displaying and storing an abnormality of a signal generator of an internal combustion engine according to claim 10, further comprising generating an abnormality signal. 12. The abnormality signal of the internal combustion engine according to claim 11, wherein the abnormality signal is kept even when a rotation speed signal subsequently appears. How to remember. 13. A signal generator for an internal combustion engine according to claim 1, wherein an abnormality is displayed and stored by using a micro computer (10). To display and memorize abnormalities. 14. A display and storage of an abnormality of a signal generator of an internal combustion engine according to claim 13, wherein a common microcomputer is used for inspection and storage of abnormality and control of the internal combustion engine. how to.