KR100489453B1 - Device for cylinder identification in a multicylinder internal combustion engine - Google Patents

Abstract

A cylinder identification device for a multicylinder internal combustion engine is provided, which does not adversely affect the identification of the cylinder so that the rotation speed varies greatly during dynamic operation.

The transmitter disk, which is rotated in synchronism with the camshaft, is scanned by the detector. The transmitter disk has a number of angle marks corresponding to the number of cylinders. One angle mark is different from the other angle marks. The other angle mark corresponds to one predetermined cylinder and is identified as follows using a calculation device. The time interval between the front edge and the rear edge of the sensor signal reflecting the segment disk is obtained, and the ratio of the time interval ti between the front edge and the rear edge and the time interval Ti between the homogeneous side edges is formed and related to each other. .

Description

Device for cylinder identification in a multicylinder internal combustion engine

The present invention relates to a cylinder identification device for a multicylinder internal combustion engine according to the preamble of the independent claim.

A method or apparatus for identifying a cylinder in a multicylinder internal combustion engine is already known and a plurality of marks are attached to the transmitter disk which is fixedly coupled to the camshaft of the internal combustion engine, the number of marks corresponding to the number of cylinders. . One of these marks is formed unlike the other marks. The mark is used to generate a reference mark, by which the angular position of the internal combustion engine can be determined. This reference mark generally corresponds to the top dead center of a given cylinder.

The transmitter disk described above is scanned by a detector, for example a hall sensor. The output signal of the detector is processed into a rectangular signal in the processing circuit. In this case, a time interval between predetermined edges of the rectangular signal is obtained by the evaluation circuit, and the reference mark is identified by evaluation of the obtained time interval. A cylinder identification device operating according to the above principle is known, for example, from the patent application 4131004 of the Federal Republic of Germany.

In order to reduce the influence of the dynamic characteristics of the rotational speed during acceleration or braking, according to the specification of German Patent Application No. 4030433, a polycylinder which operates similarly to the above-described method but otherwise forms a ratio for cylinder identification. A cylinder identification method for an internal combustion engine is proposed. The ratio forming is performed such that, by the rectangular signal formed by the evaluation circuit, the duration between the front edge and the rear edge is related to the duration between two rear edges, respectively, and the formation of this ratio is performed for each rectangular pulse. . The reference mark can be identified when the value of the ratio is different from the reference value by comparing the value of the obtained ratio with a predetermined reference value. If one cylinder is identified, the position of the other cylinder is usually also identified. The reason is that the position of the remaining cylinders relative to one selectable cylinder is always known.

The cylinder identification device of a multicylinder internal combustion engine according to the present invention having the features of claim 1 has an advantage that the cylinder identification does not adversely affect the identification of the cylinder even in the case of significant acceleration or braking. And the above advantages are obtained by the following. That is, for cylinder identification the output signal of the transmitter, for example the output signal of the camshaft transmitter scanning the characteristic surface of the transmitter disk connected with the camshaft, is evaluated, where a double ratio of a specific area of the rectangular signal is formed and other The ratio of the time interval between the edges and the time interval between the same edges of the same area of the rectangular signal is formed and normalized by the preceding ratio formed in the same way. The cylinder identification is finally performed from the value X obtained above.

Other advantages of the present invention are realized by the arrangements set forth in the dependent claims. By appropriately selecting the length of the angle mark, that is, it is possible to form a rectangular signal having a period coinciding with the so-called segment. In this case the time interval between the different edges of the rectangular signal corresponds to one partial segment.

Particularly advantageously cylinder identification is done in the control device of the internal combustion engine or in the microprocessor of the control device. After the cylinder identification is performed, the corresponding control can be executed immediately by the control device, for example, control for sequential fuel injection, ignition, knocking adjustment, and the like.

Another advantage according to the invention is that the partial segment relates to the entire segment in the individual cycles of the internal combustion engine, so that cylinder identification can be reliably and quickly performed even if there is an error in cylinder operation. Particularly preferably for this purpose, so-called fast start transmitter discs with different angle marks are used as camshaft transmitter discs. In this case, emergency operation is possible even when the crankshaft transmitter fails.

1 shows the main components of the present invention of an internal combustion engine. Reference numeral 10 denotes a transmitter disk, which is connected to the cam shaft 11 and rotates in synchronization with it. The transmitter disc 10 is provided with angle marks 12, 13, 14, 15, wherein the angle marks 12, 13, 14 are the same, and the angle marks 15 are different in a characteristic manner. It is different that the angle formed by the angle mark is smaller than the others. The angle mark is also called a reference mark or a reference segment.

The interval between one edge of one angle mark and the same edge of the next angle mark is usually referred to as segment S. In the embodiment of the four-cylinder internal combustion engine shown in FIG. 1, the angle to the length of the segment S is 90 °. According to the form of the transmitter disk of FIG. 1, all the intervals between the edges R of each degree mark are equal intervals (90 °). The transmitter disc shown in FIG. 1 is just one embodiment and may be connected to the crankshaft of the internal combustion engine. Since the transmitter disk rotates twice as fast as the camshaft, in this case the number of angular marks should be equal to half the number of cylinders.

Transmitter disk 10 comprising an angle mark is scanned by detector 16. The detector 16 is, for example, a hall sensor, whereby the output signal S1 is supplied and the signal reflects the surface structure of the transmitter disk 10 after processing into a rectangular signal, so that the angle mark is detected by the detector 16. When passing through signal S1 is high and low for another time. 2A and 2B show two different signal transition characteristics for the signal S1 obtained in a four cylinder engine, in which case the reference angle mark 15 and thus the reference angle segment is one shorter and one longer than the other angle marks. . 2, the top dead center of each cylinder is also shown.

The output signal S1 of the detector 16 is evaluated in the microprocessor 17. The microprocessor may for example be a control device of an internal combustion engine. The microprocessor 17 is applied with other input variables indicated by reference numeral 18, for example the speed n, the suction pipe pressure p, the load signal L, or the temperature eg engine temperature T and the like. The microprocessor 17 has a processing stage 19 and four memory cells SZ1, SZ2, SZ3, SZ4 in addition to other input and processing units not shown. When the number of the memory cells matches the number of angle marks or the number of cylinders of the internal combustion engine, one time may be written in each memory cell.

The microprocessor finds the time interval Ti between the signal edges which is equal to the time interval between the individual edges of the signal S1, for example the time interval ti between the other signal edges. From this time interval, the microprocessor detects the reference mark 15 corresponding to one predetermined cylinder according to the method described below. The cylinder identification can be carried out from the detection of the reference mark and after the cylinder identification has been performed, the position of the other cylinder can be found in a known manner. This is because all cylinders are in a constant relationship with each other.

After the cylinder identification has been made, the microprocessor 17 or the control device of the internal combustion engine triggers a control pulse for ignition and injection and the calculation is carried out in accordance with the remaining supplied parameters in a conventional manner and taking into account the characteristic map if necessary. Thus, sequential fuel injection, ignition adjustment or knocking control can be activated after cylinder identification or after synchronization.

Detection of the reference mark 15 and cylinder identification according to the invention is done by the microprocessor 17 as follows:

The periods ti are each measured and they are stored in the memory of the microprocessor 17. In addition, a period Ti, also called a segment time, is detected and written in the memory of the microprocessor similarly. The periods ti and Ti correspond to each other so that most of them are in the same combustion cycle. In order to reduce the dynamic influence due to the rotational speed variation in the reference mark detection or cylinder identification, the ratio ti / Ti is formed in relation to the period Ti. The ratio is normalized by the previous ratio t (i-1) / T (i-1). Thus, the following values are finally formed.

Xi = (ti / Ti) / t (i-1) / T (i-1)

Depending on the value Xi, another value A is determined and the value is stored in a memory cell SZi which is randomly assigned to each cylinder. After a predetermined passage is detected in the memory cell Szi, a reference mark is detected or a reference cylinder is identified.

Obtaining the value A depending on the value Xi is done by allowing the value A to take -1, 0 or +1 at that time, depending on the magnitude of the value of (Xi).

It can be seen from the signal sequence shown in FIG. 2A that t2 > t1, t3, t4 is established when the rotational speed of the cam axis is constant. That is, the period t2 corresponding to the reference mark is always larger than the other periods. In this case the periods t1, t3, t4 are the same within the range of manufacturing tolerances of the transmitter disk. For the time interval Ti, T1 = T2 = T3 = T4 is established. Considering the above relationship, the following fact holds for the relationship between the values A and Xi.

If Xi <1, then A = -1

A = 0 if Xi = 1

If Xi> 1, then A = 1

According to the embodiment shown in Fig. 2B in which the period t2 of the reference mark is shorter than the other periods t1, t3, t4, the relationship between (A) and (Xi) is reversed.

The value A is applied to the memory cell SZi corresponding to each cylinder and in this case typically the memory cell is set to zero at startup or reset. Writing to the memory cell is then done so that the next value is written to the next memory cell, and the contents of the cell change from (Zi) to (Zi + A) and then the value (A) is set to the value -1, as described. It can have 0 or +1.

As shown in Fig. 2A, when the period t1 is first obtained, a value zero is applied to the corresponding memory cell SZ1 for (A). This is because the ratio Xi = (t1 / T1) / (t4 / T4) ≦ 1. Alternatively, the ratio within the t2 range has a value greater than or less than zero depending on whether the period before the reference mark is related to the corresponding entire period or whether the period after the reference mark is related to the corresponding total period.

In the error-free operation, since the reference mark always appears at the same position, the value -1 is always written to one memory cell, while the value +1 is always written to the memory cell following it. The value zero is written to the other memory cells, respectively. Therefore, by comparing the contents of each memory cell with a predetermined threshold value or by comparing each memory cell with each other, information as to whether or not the period corresponding to the memory cell or the corresponding angle mark is a reference mark is surely obtained.

According to one simplified embodiment of the present invention, the value Xi can be directly compared with one or a plurality of suitable limit values and the reference mark and corresponding cylinder can be identified by limit value detection.

Reference mark detection, i.e., another possible configuration for cylinder identification, compares a plurality of consecutive ratios Xi with each other and detects a reference mark if, for example, X1 &lt; X2 &lt; The values of (X1) and (X3) can then be additionally weighted by a selectable coefficient that must match the length of the existing angle mark.

The evaluation process can also be carried out by means of a transmitter disk configured in other shapes, such as a so-called fast start transmitter disk. In this case, two segment lengths equal to one another are generated, and the other segment lengths are shorter or longer than the length of the reference segment, for example, the same segment length is shorter than the reference segment and is longer than the other reference segments. The two reference segments are then directly connected to each other or offset 180 °. Such a transmitter disk produces a signal passing characteristic as shown in FIG. 4 for a four cylinder internal combustion engine.

With the transmitter disc generating signal transition characteristics with periods t1, t2, T1, T2 as shown in FIG. 3A or 3B, the formation of the ratio is already sufficient for cylinder identification. Because for the signal lapse characteristic according to Fig. 3A,

[(t2 / T2) / (t1 / T1)] << 1

Is established or in the signal region according to Fig. 3B,

[(t2 / T2) / (t1 / T1)] 〉〉 1

This is true.

In an internal combustion engine having a crankshaft transmitter and a camshaft transmitter as described above, when a failure of the crankshaft transmitter is detected, emergency operation is possible in which information originally supplied from the crankshaft transmitter is obtained from information of the camshaft transmitter. Do.

The present invention provides a cylinder identification device for a multi-cylinder internal combustion engine that does not adversely affect the identification of the cylinder even when the rotational speed is greatly changed during dynamic operation, that is, during a significant acceleration or braking.

1 shows a first transmitter disk of an embodiment according to the invention, which is partly known in German Patent Application Publication No. 4131004, but in which signal evaluation is carried out in a different manner.

2A and 2B are diagrams showing corresponding signal transition characteristics.

3A and 3B show signal progress characteristics of a fast start transmitter disc.

4 is a diagram illustrating signal progress characteristics of the fast start transmitter disc.

* Explanation of symbols for the main parts of the drawings

10: transmitter disk

12, 13, 14, 15: angle mark

16: detector

17 microprocessor

19: processing stage

SZ1, SZ2, SZ3, SZ4: Memory Cells

Claims (9)

The transmitter disk 10 and the fixed detector 16 which rotate in synchronization with the shaft 11 of the internal combustion engine are provided, and the transmitter disk has a plurality of angle marks 12, 13, 14 correlated with the number of cylinders. 15, wherein at least one of the angle marks forms a reference mark 15 which characterizes the position of a predetermined cylinder, unlike the other angle marks, and the detector comprises the transmitter disc 10. ) Is supplied to supply an output signal S1 corresponding to the angle marks 12, 13, 14, and 15, and the output signal S1 is supplied to the evaluation means 17, and the evaluation means is supplied from the output signal. Configured to detect a time interval Ti between the same edge as the time interval ti between the front edge and the rear edge, and to obtain the value Xi, the actual ratio ti / Ti to the preceding ratio t (i− 1) / T (i-1)), and the internal combustion of the cylinder in which the reference mark is detected from the value Xi In the cylinder identification device in the tube, Said value (Xi) is compared with a preceding or subsequent value (Xi-1, Xi + 1), and the reference mark (15) is detected from the difference of said values, The cylinder identification apparatus of a multicylinder internal combustion engine. 2. A cylinder identification device for a multicylinder internal combustion engine according to claim 1, wherein said evaluation means (17) is provided with a microprocessor (17), such as a microprocessor of a control device for an internal combustion engine. A value A according to claim 1 or 2, wherein a different value A is formed from the value Xi, which is -1, 0 or +1, and the evaluating means 17 comprises each cylinder 20, 21, 22, 23) A cylinder identification device for a multicylinder internal combustion engine, characterized in that each memory cell has one memory cell, and the values are written in associated memory cells (20, 21, 22, 23), respectively. The method of claim 3, wherein the contents of the memory cells 20, 21, 22, and 23 are continuously updated until the contents of one memory cell 20, 21, 22, and 23 exceed a threshold value. Is detected and the angle marks 12, 13, 14, 15 corresponding to the associated memories 20, 21, 22, 23 are detected as reference marks or the corresponding memory 20, 21, 22, 23, or corresponding A cylinder identification device for a multicylinder internal combustion engine, characterized in that a cylinder corresponding to an angle mark (12, 13, 14, 15) is detected as a reference cylinder (15). 5. A cylinder identification device for a multicylinder internal combustion engine according to claim 4, wherein the contents of said memory cells (20, 21, 22, 23) are set to zero at start or reset. 6. The multicylinder internal combustion engine according to claim 5, characterized in that reference mark detection and corresponding cylinder identification are performed when a specific sequence of threshold values in said memory cells (20, 21, 22, 23) is exceeded or falls below. Cylinder Identification Device. 3. The transmitter disc 10 according to claim 1 or 2, wherein the transmitter disc 10 has two different angle marks from the remaining angle marks 12, 13, 14 and 15, resulting in two different segment lengths, one segment A cylinder identification device for a multi-cylinder internal combustion engine, characterized in that the length is shorter than the reference segment, the other reference segment is long, and the two reference segments are directly continued in succession or offset by an angle of 180 °. 3. Transmitter disc 10 according to claim 1 or 2, which is different from the remaining angle marks 12, 13, 14 and 15, but which has at least two angle marks which are identical to one another, A cylinder identification device for a multicylinder internal combustion engine, characterized in that the reference segments are shorter or longer than the reference segment and the reference segments continue in direct succession. 3. The control device according to claim 1 or 2, wherein the control device to which other data on the operating state of the internal combustion engine is supplied is controlled from the data and the stored characteristic map after the cylinder identification, i.e. after the synchronization, for control signals and / or injection. The cylinder identification device of the multicylinder internal combustion engine, characterized in that for transmitting a different control signal according to.

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