KR20130008025A - Method and device for operating an internal combustion engine in the event of a fault of a crankshaft sensor - Google Patents

Abstract

The present invention relates to a method of operating an internal combustion engine in the event of a failure of a crankshaft sensor, in which the internal combustion engine (1) has two or more camshafts (8, 9, 10, 11), and camshafts (8, 9, 10). The speed and / or state of the internal combustion engine 1 is derived from the signal picked up at 11). In order to improve the exhaust gas behavior of the internal combustion engine even during the emergency operation mode of the crankshaft, only the first camshaft 11 is used to detect the rotational speed and / or state of the internal combustion engine 1, while the second camshaft 8, The rotation angles of the second camshafts 8, 9, 10 are adjusted to adjust the variable valve trains of the intake or exhaust valves 6, 7 of the internal combustion engine 1 driven by 9, 10.

Description

METHOD AND DEVICE FOR OPERATING AN INTERNAL COMBUSTION ENGINE IN THE EVENT OF A FAULT OF A CRANKSHAFT SENSOR}

The present invention provides a method for operating an internal combustion engine in the event of a failure of the crankshaft sensor and the implementation of the method, wherein the internal combustion engine has two or more camshafts, and the rotation speed and / or state of the internal combustion engine is derived from a signal picked up from the camshaft. Relates to a device.

In today's vehicles, it is important to accurately detect the rotational speed of the internal combustion engine, because this variable is taken into account in the numerous closed-loop / open-loop control processes of the vehicle. In general, the rotational speed is derived from the rotational speed of the crankshaft driven by the mechanical energy generated in the combustion process. The crankshaft is then scanned by a crankshaft sensor that detects the rotational speed and position of the crankshaft. The signal is provided via a suitable sensor and evaluated at the control device as an evaluation measure for the speed and / or condition of the internal combustion engine. At this time, the injection timing and the ignition timing of the internal combustion engine are detected.

In the event of an abnormality or interference of the crankshaft sensor signal, the control device is switched to the crankshaft emergency operation mode, in which the state of the internal combustion engine is detected from the position of the camshaft driven by the crankshaft. A precondition for the crankshaft emergency operation mode is that the camshaft must be fixed at a predetermined position with respect to the crankshaft so as to accurately detect the state of the internal combustion engine. Therefore, the camshaft is no longer used for camshaft adjustment in different operating regions of the internal combustion engine, so that the exhaust gas behavior of the internal combustion engine is deteriorated.

It is therefore an object of the present invention to provide a method and apparatus for operating an internal combustion engine in which the exhaust gas behavior of an internal combustion engine is improved even in a crankshaft emergency operation mode when a crankshaft sensor fails or fails.

In order to solve the above problem according to the present invention, only the first camshaft is used to detect the rotational speed and / or the state of the internal combustion engine, while in the intake valve or exhaust valve of the internal combustion engine driven by the second camshaft. The rotation angle of the second camshaft can be adjusted for the adjustment of the variable valve train. This has the advantage that the speed or state of the internal combustion engine detected during the crankshaft emergency operating mode can be detected reliably and accurately through only a single camshaft. In addition, the variable valve opening time is adjusted using the second camshaft. The rotation of the second camshaft improves the exhaust gas behavior of the internal combustion engine, and the positive influence of the exhaust gas behavior is maintained even during the crankshaft emergency operation mode. Adaptation of the valve opening time allows for increased efficiency of the internal combustion engine, which has the effect of output gain and torque gain or fuel savings.

Advantageously, the first camshaft takes a reference position with respect to the crankshaft driven by the internal combustion engine and rotates at a preset speed ratio with respect to the crankshaft, wherein the rotational movement of the camshaft is detected by the camshaft sensor. As the movement of the camshaft is fixedly and clearly assigned in relation to the movement of the crankshaft through the adjustment of the reference position, the state of the internal combustion engine can be detected reliably.

In one variant, the first camshaft in the reference position with respect to the crankshaft opens and / or closes the exhaust valve of the internal combustion engine, and the second camshaft provided with rotational movement opens and / or closes the intake valve of the internal combustion engine. do. Since the control time of the intake valve and exhaust valve in the camshaft adjustment varies with the rotational speed, cylinder filling as efficient as possible in all rotational speed ranges can be achieved. The required exhaust gas reduction effect can only be achieved through the rotation of the camshaft controlling the intake valve. Therefore, adjustment of the variable valve train is sufficient with one camshaft.

In one embodiment, when using two or more camshafts, only the first camshaft is fixed at the reference position with respect to the crankshaft, and the remaining camshafts have their rotation angles adjusted. All other camshafts in addition to one camshaft are used for the operation of the intake valve or exhaust valve, allowing for optimal adjustment of the variable valve train, which is reflected in the improvement of the exhaust gas behavior of the internal combustion engine during the crankshaft emergency operation mode. When a plurality of camshafts are used, not only the intake camshaft but also the exhaust camshaft for controlling the exhaust valve of the internal combustion engine is adjusted. Such adjustment of the exhaust camshaft allows the internal exhaust gas recirculation to be changed in the form of nitrogen oxide emission reduction. In addition, simultaneous adjustment of the intake camshaft and the exhaust camshaft increases the possibility of overlap of the open time of the intake valve and the exhaust valve, which makes the optimization of gas flow in the internal combustion engine much better.

In addition, the rotation angle of the camshaft is adjusted based on the rotational speed and / or the state of the internal combustion engine detected through the camshaft sensor. Since the adjustment of the camshaft changes the rotational angle with respect to the crankshaft and the adjustment depends on the rotational speed of the detected internal combustion engine, the angle of rotation in the crankshaft emergency operation mode is determined by the rotational speed detected using the first camshaft. Calculated on the basis of

In one embodiment, when the rotation angle is adjusted, the camshaft driven by the crankshaft is moved from a preset position with respect to the crankshaft so that the control times of the intake valve or exhaust valve of the internal combustion engine can be changed. The adjustment is simply made in a mechanical way, in which case a hydraulic phase adjuster is installed between the crankshaft and the camshaft and placed at the end of each camshaft for power transmission.

In another embodiment, the adjustment of the second camshaft is made between two preset angles of rotation within one adjustment range of the second camshaft. Therefore, the control cost of the phase adjuster is reduced. The adjustment range is usually 60 ° crankshaft.

As an alternative, the adjustment of the second camshaft is made continuously within the adjustment range of the camshaft. Despite the complex control, the exhaust gas behavior of the internal combustion engine can be advantageously adjusted as it can be comfortably reacted to the various operating states of the internal combustion engine during continuous adjustment of the camshaft.

In addition, the present invention relates to an apparatus for operation of an internal combustion engine in the event of a failure of a crankshaft sensor, wherein the internal combustion engine has two or more adjustable camshafts, and the rotational speed and / or rotation of the internal combustion engine from signals picked up in the camshaft rotation. The condition is detected. In order to improve the exhaust gas behavior of the internal combustion engine even during the crankshaft emergency operation mode, only the first camshaft is used to detect the rotational speed of the internal combustion engine, and the intake valve or the exhaust valve of the internal combustion engine driven by the second camshaft. Means are provided for adjusting the rotation angle of the second camshaft to adjust the variable valve train. The system also improves the exhaust gas behavior of the internal combustion engine during the crankshaft emergency mode of operation.

In one embodiment, the first and second camshafts are controlled by the control device in each rotational movement, and the camshaft sensor detects the rotational movement of the first camshaft by a control device that adjusts the first camshaft to a reference position with respect to the crankshaft. And the control device detects the rotational speed and / or state of the internal combustion engine from the rotational movement, and adjusts the adjustment device connected to the second camshaft based on the detected rotational speed or state of the internal combustion engine. Control for the rotation of the angle. In addition to accurately detecting the state or rotational speed of the internal combustion engine using only one camshaft, the variable valve opening time is adjusted with the second camshaft even during the crankshaft emergency operation mode. Through the rotation of the second camshaft, the ratio of fresh air and fuel is optimized to improve the exhaust gas behavior of the internal combustion engine, and the positive influence of the exhaust gas behavior is maintained even during the crankshaft emergency operating mode. Appropriate adjustment mechanisms are then used as adjustment members, which are operated either electrically or hydraulically and simply realize the adjustment in a mechanical manner and are arranged at the end of each camshaft for power transmission.

Many embodiments are possible in the case of the present invention. Any one of these will be described in detail with reference to the drawings.
1 is a diagram showing the basic structure of a V-shaped internal combustion engine having four camshafts.
FIG. 2 is a basic schematic view of arranging a crankshaft sensor and a camshaft sensor in the V-shaped internal combustion engine according to FIG. 1.
3 is a view of a camshaft including a camshaft adjuster.

The same features have the same reference numerals.

1 shows the basic structure of a V-shaped internal combustion engine 1. In FIG. 1 the cylinders 2 of the internal combustion engine 1 are arranged in two sections 3 and 4 in a V-shape, and the crankshaft 5 is arranged at the intersections of both sections 3 and 4. It is. Each section 3, 4 is generally referred to as a bank. Each cylinder 2 has one or a plurality of intake valves 6 and an exhaust valve 7. Outside air and fuel are supplied to each cylinder 2 of the internal combustion engine 1 via the intake valve 6, and combustion products of the cylinder 2 are exhausted in the form of exhaust gas by the exhaust valve 7. Is discharged from The intake valve 6 of the first section 3 of the cylinder 2 is connected with the first camshaft 8, and the exhaust valve 7 of the first section 3 is actuated by the second camshaft 10. do. Similarly, the intake valve of the second section 4 of the cylinder 2 is connected to the third camshaft 9, and the exhaust valve 7 of the second section 4 mutually interacts with the fourth camshaft 11. Works. On each camshaft 8, 9, 10, 11, an eccentric cam (projection), not shown in detail, for each valve 2 is located. Since the camshaft rotates about its own axis, and through this rotational movement, the rotational movement is converted into a short longitudinal movement by the cam, so that the intake or exhaust valves 6 and 7 subordinate to the cam are opened. If the cam continues to rotate, the valves 6, 7 are closed again through the valve spring 19 (FIG. 3).

At the one end of the crankshaft 5 a speed sensor wheel 12 is arranged in the form of a gear, which is shown next to the internal combustion engine 1, which is only outlined in FIG. 2. The speed sensor wheel 12 has a certain number of teeth 13 made of iron or steel, which teeth are continuously arranged around the speed sensor wheel 12 and then one gap or a plurality of gaps 14. It is interrupted by). A crankshaft sensor 15 is disposed opposite the speed sensor wheel 12 to scan the teeth and the gap (s) 14, wherein the magnetic field formed by the crankshaft sensor 15 using a magnet is By intermittent by the field 13, an alternating voltage is induced into the coil of the crankshaft sensor 15, which transmits the alternating voltage to the control device 16 for evaluation. The gap 14 of the crankshaft sensor wheel 12 signals the end of one rotation of the crankshaft 5, at which time one operating cycle of the cylinder 2 ends.

On each camshaft 8, 9, 10, 11 a camshaft sensor wheel 17 is arranged, which is shown only in the example of the camshaft 9 in FIG. 2. The camshaft sensor wheel 17 also has teeth that are interrupted by gaps. However, the camshaft sensor wheel 17 is not as finely divided as the crankshaft sensor wheel 12 with (60-2) teeth, and the camshaft sensor wheel 17 has only three teeth in this embodiment.

The camshafts 8, 9, 10, 11 are driven by the crankshaft 5 via gears not shown in the figure, the camshafts 8, 9, 10, 11 being rotated by the crankshaft 5. It has a speed ratio to rotate at half the speed of the number.

Each camshaft 8, 9, 10, 11 is rotated by a predetermined angle with respect to the crankshaft 5 to change the control time of the intake valve or the exhaust valve via the camshaft 8, 9, 10, 11. do. The camshaft 8, 9, 10, 11 is adjusted based on the rotational speed of the internal combustion engine 1, and the camshaft is adjusted by opening the intake or exhaust valves 6, 7 by the crankshaft 5. It means to change for the crank angle of. For this purpose, a hydraulic camshaft adjuster 20 is used, for example as shown in relation to the camshaft 9 in FIG. 3. As already explained, the gear 21 of the gear rotates the camshaft 9. The valve 2 is closed in the forward direction or the perceptual direction by the camshaft adjuster 20, which is also connected to the control device 16 and driven by the control device, moves the position of the camshaft 9 toward the gear 21. As a result, an increase in the efficiency of the internal combustion engine 1 is achieved.

In particular, the overlap of the opening times of the intake valve and the exhaust valve fundamentally affects the characteristics of the internal combustion engine 1. The internal combustion engine 1 having a small overlap has a rather high torque at low revolutions. If the overlap is large, a higher maximum output of the internal combustion engine 1 can be achieved.

When it is confirmed that the crankshaft sensor 5 used to check not only the rotational speed of the internal combustion engine 1 but also its state provides a significantly distorted output signal or no longer provides a signal at all, the control device ( 16 is switched to the so-called crankshaft emergency operation mode. In this crankshaft emergency operation mode, one of the four camshafts 8, 9, 10, 11 of the internal combustion engine 1 is moved to the reference position with respect to the crankshaft 5. Such a camshaft is the camshaft 11 which controls the exhaust valve 7 of the 2nd section 4 of the cylinder 2 in this embodiment. Since the relationship between the movement of the crankshaft 5 and the movement of the camshaft 11 is fixed by the reference position, the engine state can be detected constantly. In the camshaft 11, the camshaft sensor wheel 17 is also disposed at one end, and the camshaft sensor 18 is located opposite the camshaft sensor wheel (FIG. 2). The magnetic field of the camshaft sensor 15, which is formed as a hall sensor, is then changed by the individual teeth of the camshaft sensor wheel 17, which is transmitted as a signal to the control device 16, from which the control device receives an internal combustion engine 1. Derive the number of revolutions and state.

The remaining three camshafts 8, 9 and 10, which are not necessary for the detection of the state and the rotational speed of the internal combustion engine 1, are used for the adjustment, so that both intake camshafts 8 and 9 and the remaining exhaust camshaft 10 By the control of the exhaust gas behavior of the internal combustion engine 1 is improved. By employing a plurality of camshafts in the manner already described, the intake and exhaust control times can be set which lead to cylinder filling as efficient as possible in all of the rotational speed regions of the internal combustion engine 1.

Claims (10)

The internal combustion engine 1 has two or more camshafts 8, 9, 10, 11 and the rotational speed and / or state of the internal combustion engine 1 from signals picked up by the camshafts 8, 9, 10, 11. In the method of operating the internal combustion engine in the event of a failure of the crankshaft sensor,
Intake or exhaust of the internal combustion engine 1 driven by the second camshaft 8, 9, 10 while only the first camshaft 11 is used to detect the rotational speed and / or state of the internal combustion engine 1. A method of operating an internal combustion engine in the event of a failure of the crankshaft sensor, characterized in that the angle of rotation of the second camshaft (8, 9, 10) is adjusted to adjust the variable valve train of the valve (6, 7). 2. The first camshaft (11) according to claim 1, wherein the first camshaft (11) takes a reference position with respect to the crankshaft (5) driven by the internal combustion engine (1), rotates at a preset speed ratio with respect to the crankshaft (5), Rotational movement of the camshaft (11) is detected by a camshaft sensor (18), the method of operating the internal combustion engine in the event of a failure of the crankshaft sensor. 3. The first camshaft (11) according to claim 1 or 2, wherein the first camshaft (11) located at a reference position with respect to the crankshaft (5) opens and / or closes the exhaust valve (7) of the internal combustion engine (1) and rotates in rotation. The second camshaft (8, 9, 10) provided is characterized in that the opening and / or closing the intake valve (6) of the internal combustion engine (1), the method of operating the internal combustion engine in the event of a crankshaft sensor failure. The method according to claim 1, 2 or 3, wherein when using two or more camshafts 8, 9, 10 and 11, only the first camshaft 11 is fixed at a reference position with respect to the crankshaft 5, The remaining camshaft (8, 9, 10) is characterized in that its rotation angle is adjusted, the operation method of the internal combustion engine in the event of a crankshaft sensor failure. Crank according to claim 4, characterized in that the adjustment of the rotation angle of the camshafts (8, 9, 10) is made in accordance with the rotational speed and / or state of the internal combustion engine (1) detected through the camshaft sensor (18). How the internal combustion engine works in the event of a failure of the axis sensor. The intake of the internal combustion engine (1) according to claim 5, wherein the camshafts (8, 9, 10) driven by the crankshaft (5) are moved from a preset position with respect to the crankshaft (5) during the rotation angle adjustment. Or the control time of the exhaust valve (6, 7) can be changed, the method of operating the internal combustion engine in the event of a failure of the crankshaft sensor. The method according to any one of claims 1 to 6, wherein the adjustment of the second camshafts (8, 9, 10) is between two preset rotation angles within the adjustment range of the second camshafts (8, 9, 10). The method of operating the internal combustion engine in case of failure of the crankshaft sensor, characterized in that made in. The crankshaft according to any one of claims 1 to 6, wherein the adjustment of the second camshafts (8, 9, 10) is made continuously within the adjustment range of the camshafts (8, 9, 10). How the internal combustion engine works in case of sensor failure. Of the crankshaft sensor, in which the internal combustion engine 1 has two or more camshafts 8, 9, 10, 11, and the rotational speed and / or state of the internal combustion engine 1 is detected from the signal picked up in the camshaft rotation. In the operating device of the internal combustion engine in case of failure,
Intake or exhaust of the internal combustion engine 1 driven by the second camshaft 8, 9, 10 while only the first camshaft 11 is used to detect the rotational speed and / or state of the internal combustion engine 1. In case of failure of the crankshaft sensor, means are provided for adjusting the rotation angle of the second camshafts 8, 9, 10 to adjust the variable valve trains of the valves 6, 7. The operating device of the internal combustion engine. 10. The rotational motion of each of the first and second camshafts (8, 9, 10, 11) is controlled by the control device (16), and the first camshaft to a reference position with respect to the crankshaft (5). The control device 16 for adjusting (1) is connected with a camshaft sensor 18 for detecting a rotational motion of the first camshaft 11, and the control device 16 is connected to the internal combustion engine 1 from the rotational motion. The adjustment device 20 connected to the second camshaft 8, 9, 10 based on the detected speed of the internal combustion engine 1 and detecting the rotational speed and / or state of the second camshaft 8, 9, 10. Operating device of the internal combustion engine in case of failure of the crankshaft sensor, characterized in that for controlling the rotation of the rotation angle.

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