JP4589060B2 - Method for starting a multi-cylinder internal combustion engine and internal combustion engine - Google Patents

Description

The present invention is particularly a method for starting the gasoline direct injection type multi-cylinder internal combustion engine of a motor vehicle, when the starting process requirements, at least one piston of the at least one sheet in cylinder which is associated arranged in the piston detecting a position, at this time, the fuel, the piston is in the working stroke, injected into one or more cylinders, at this time, the fuel and gas in at least one cylinder in the working stroke mixture is ignited, the one or more pistons, the piston of the other cylinder, to a method for shifting to a forward movement to implement the working stroke via a crank shaft connecting the pistons.

  The invention further provides an internal combustion engine for carrying out the method, in particular with a plurality of cylinders of a motor vehicle, the internal combustion engine detecting the position of at least one piston in the cylinder of the internal combustion engine. The invention is of the type having a device and a fuel metering system for injecting fuel into the combustion chamber of at least one cylinder whose piston is in the working and / or compression stroke. The invention also relates to a control and / or adjustment device for an internal combustion engine of a motor vehicle and a computer program.

  A method for starting a multi-cylinder internal combustion engine of the type mentioned at the outset is known, for example, from German Offenlegungsschrift 3,117,144. This known method operates without an electric motor type starter. In this case, in a stopped internal combustion engine, the amount of fuel required for combustion is injected and ignited into the combustion chamber of one or more cylinders whose pistons are in the working phase. Then, as soon as that piston reaches the working position, the piston injects fuel into the combustion chamber of one or more cylinders performing the next working stroke and ignites. In this way, the internal combustion engine can be constructed without an electric motor type starter and thus without the components necessary for the starter. In addition, the battery of the internal combustion engine can be reduced in size. This is because it is not necessary to supply electrical energy for the starter and other electrical components.

In known methods for starting an internal combustion engine, it is necessary to accurately take into account the strokes (compression stroke, working stroke, exhaust stroke, intake stroke) in which each piston of the internal combustion engine and the intake and exhaust valves of the combustion chamber are present. there Ru. As a result, in a four-cylinder or six-cylinder internal combustion engine, each stroke of the internal combustion engine is filled with fuel only in the combustion chamber of one cylinder, that is, the cylinder in which the piston is in the working position, and ignited. In the known method, on the one hand, the compression stroke, the working stroke, the exhaust stroke and the intake stroke are carried out continuously in a fixed manner for each cylinder, and on the other hand, the distribution of the stroke to each cylinder is defined.

  According to German Offenlegungsschrift 19743492 as another prior art, a method for starting an internal combustion engine without an electric starter is known.

Also, in German Offenlegungsschrift 10020104, the intake or exhaust valve of at least one cylinder whose piston is behind top dead center is brought into a position corresponding to the working phase before the starting process. Thus, the method described at the beginning is disclosed. For this purpose, this known method, for example, controls the intake and / or exhaust valves independently of the camshaft so that each intake and exhaust valve is independent of the other valves. And independently of the position of the camshaft.
German Patent Publication No. 3117144 German Federal Republic of Patent Publication No. 1974492 German Patent Publication No. 10020104 German Patent No. 19724921

  An object of the present invention is to enable a multi-cylinder internal combustion engine to be started quickly and reliably in an as simple a manner as possible without an electric starter.

  According to the method of the present invention which has solved this problem, in the method of the type described at the beginning, in order to reduce the movement resistance of the piston, a pressure reducing valve is provided in at least one other cylinder, and the pressure reducing valve is compressed. Released during the stroke.

  When the internal combustion engine is started without a starter while the engine is stopped, it is always necessary to start combustion in at least one combustion chamber. The resulting combustion chamber pressure moves at least one associated piston downward and moves the internal combustion engine. This movement is damped by the compression operation during the compression formation phase. This compression operation can sometimes work to stop this movement. This type of damping action also prevents frictional action based on compression in one or more other cylinders (the piston of this cylinder is not in working phase and is not ignited) To achieve this, according to the present invention, in order to exhaust a part of the gas present in the cylinder from the cylinder and thereby reduce the damping and friction effects, at least one other One or more pressure reducing valves are provided in the cylinder and open. In this manner, the start certainty in the direct engine injection at the time of direct start is improved.

  In this case, the use of a pressure-reducing valve in order to avoid the resonance speed is known, for example, from DE 197 24 921. In this case, a conventional starter is used, and the pressure reducing valve is opened only at the ignition speed or less.

In this case, according to a first embodiment of the invention, at least one piston is injected by injecting into the cylinder or cylinders during the compression stroke before top dead center and igniting the generated mixture. retracting rotational movement, whereby by compressing the gas at the same time the cylinder when Ru is allowed transition to the starting position of the piston working stroke of another cylinder, one cylinder in the working stroke, or six or more In the engine having the above cylinders, the piston is first moved backward and moved to the starting position immediately after the top dead center in the forward rotation direction of the crankshaft before being injected into the plurality of cylinders. As soon as this at least one further cylinder is located in the starting position during the working stroke, the method is carried out, in which case fuel is injected into one or more cylinders during the working stroke and pre-compressed fuel. a mixture of the gas is ignited, whereby the forward movement is started. By this forward movement, one or more cylinders already in the compression stroke that have started the reverse movement are transferred to the compression stroke, in which case the pressure reducing valve is opened. In this case, an intake valve and an exhaust valve are assigned to each cylinder in order to allow a gas necessary for combustion to flow in and exhaust the gas burned after ignition.

  When the pressure reducing valve in the cylinder during the compression stroke is opened, as soon as the cylinder during the compression stroke transitions to the working stroke, the pressure reducing valve is connected to its opening and closing strokes, on the one hand, the braking action of the compression pressure formation. Needs to be controlled so that there is sufficient charge gas remaining for the subsequent combustion in the cylinder.

  After the reverse rotation, if the pressure reducing valve in the reversing start cylinder is opened, this pressure reducing valve must be closed after reaching top dead center at the earliest and at the latest with the closing of the exhaust valve.

  In this case, the pressure reducing valve in at least one cylinder is opened in order to reduce the resistance both during the backward movement and during the forward movement. Basically, depending on the number of cylinders, it is also conceivable to provide four, six or more pressure reducing valves in the cylinder during the compression stroke. In this case, the plurality of pressure reducing valves are opened in the cylinder during the compression stroke one after another or simultaneously. Similarly, it must be taken into account that if the braking action of compression is reduced, it is closed again as appropriate so that sufficient air supply is provided for the subsequent combustion.

  In order to control combustion together with single injection into the cylinder, it is conceivable to perform multiple injections. Each injection must be provided with an appropriate mixture formation time before ignition. It is also conceivable to provide a spark plug or other ignition possibilities for ignition, for example.

  In this case, according to an advantageous embodiment, the fuel compressed in the combustion chamber of the cylinder or cylinders is ignited during the working phase immediately after the top dead center of the piston of each cylinder. . Optionally, the compressed fuel is ignited just before or at the top dead center of the piston of each cylinder, in which case the ignition needs to take place in order to obtain the desired direction of rotation of the internal combustion engine. There is.

  In an advantageous manner, the fuel is supplied in a conventional manner, for example via a fuel pump, during the starting process.

  At the end of the method of the present invention, the pressure reducing valve was prevented from being further opened when a predetermined number of revolutions was reached. The start-up process is then terminated and the vehicle can be driven in response to a travel request or transition to normal idling.

  Other advantages and features of the invention are described in other specifications. The present invention is described in detail below with reference to the drawings. In this case, all features described or illustrated may be used alone or in any combination, regardless of what is summarized in the claims or their citation, and in the detailed description or in the drawings. Regardless of what forms the subject of the invention.

  FIG. 1 shows an internal combustion engine denoted as a whole by reference numeral 1. The internal combustion engine 1 has a piston 2 that can reciprocate within a cylinder 3. The cylinder 3 includes a combustion chamber 4, and an intake pipe (intake pipe) 6 and an exhaust pipe (exhaust pipe) 7 are connected to the combustion chamber 4 via a valve 5. Furthermore, an injection valve 8 controlled by a signal Ti and a spark plug 9 controlled by a signal ZW are assigned to the combustion chamber 4.

  In the first mode of operation, i.e. in the stratified combustion mode of operation of the internal combustion engine 1, the fuel is passed from the injector 8 during the compression phase by the piston 2, positionally in the combustion chamber 4 and directly around the spark plug 9. Specifically, the fuel is injected immediately before the top dead center OT of the piston 2 or the ignition time. The fuel is then ignited by the spark plug 9 and the piston 2 is driven by the expansion of the ignited fuel during the subsequent work phase.

  In the second mode of operation, i.e. the homogeneous combustion mode of the internal combustion engine 1, fuel is injected from the injection valve 8 into the combustion chamber 4 during the suction phase by the piston 2. The injected fuel is swirled by the simultaneously sucked air, and is thereby distributed almost uniformly (homogeneously) in the combustion chamber 4. The fuel / gas mixture is then compressed during the compression phase and then ignited by a spark plug 9. The piston 2 is driven by the expansion of the ignited fuel.

  In both the stratified combustion operation mode and the homogeneous operation mode, the crankshaft 10 is replaced by a rotational motion by the driven piston 2, and the wheels of the automobile are driven by this rotational motion. A rotational speed sensor 11 is assigned to the crankshaft 10, and the rotational speed sensor 1 generates a signal N in relation to the rotational movement of the crankshaft 10.

The fuel is injected into the combustion chamber 4 by the injection valve 8 under high pressure in the stratified combustion operation mode and the homogeneous operation mode. For this purpose, an electric fuel pump is provided, which is driven independently of the internal combustion engine 1 to generate a so-called rail pressure.

  The fuel mass injected into the combustion chamber 4 by the injection valve 8 in the stratified combustion operation mode and the homogeneous combustion operation mode is controlled and / or adjusted by the control device 12 in connection with low fuel consumption and / or low generation of harmful substances. Is done. For this purpose, the control device 12 comprises a microprocessor, which stores in the control element, in particular a read-only memory, a program suitable for controlling and / or adjusting.

  The control device 12 is loaded with an input signal representing the operating value of the internal combustion engine 1 measured by the sensor. For example, the control device 12 is connected to an air mass sensor disposed in the intake pipe 6, a lambda sensor (O2 sensor) disposed in the exhaust pipe 7, and the rotation speed sensor 11. The control device is connected to an accelerator pedal sensor 13. The accelerator pedal sensor 13 generates a signal SP indicating the position of the accelerator pedal operated by the driver.

  Depending on the output signal generated by the control device, the characteristics of the internal combustion engine 1 can be influenced via the actuator in accordance with the desired control and / or adjustment. For example, the control device 12 is connected to the injection valve 8 and the spark plug 9 and generates signals Ti and ZV necessary for control.

  The method according to the present invention will be described in detail with reference to the following drawings. In this case, since the rotational speed sensor 11 is configured as an absolute value angle signal transmitter, the rotational speed sensor 11 generates a rotational angle ° KW of the crankshaft, particularly after the internal combustion engine 1 is stopped, to control the control device. 12 can be transmitted. In this manner, the position of the piston 2 in the cylinder 3 is calculated even at a rotational speed of zero before the start of the starting process.

  In the method shown in FIG. 2, when the internal combustion engine 1 is stopped, the cylinder A is positioned before the top dead center (ZOT) before ignition in the compression stroke. In this case, the combustion chamber 4 is closed. Fuel is injected into the combustion chamber 4 once or a plurality of times via an injection valve 8. After a predetermined mixture formation time, the mixture is ignited by the spark plug 9. This is indicated by the ignition spark symbolized in the picture (stage 1, left side).

  The generated combustion chamber pressure drives the piston 2 of the cylinder A downward, and the internal combustion engine 1 first moves in the reverse direction indicated by the arrow 14.

  In this case, the start position and the amount of fuel injected are such that the energy generated by combustion rotates the piston 2 located on the opposite side of the cylinder B during the working stroke in the reverse direction beyond its top dead center ZOT. It is set to an extent that is insufficient for moving.

  In this case, the crankshaft 10 is rotated once by an electric motor type starter, thereby starting a necessary start position. However, this type of starter only needs to correct the starting position and does not need to increase the engine speed to the required starting engine speed, so that it has a significantly smaller or optimized output. What is necessary is just to design dimensions.

In this case, the reverse rotation of the starter cylinder A is designed to ensure that the reverse rotation is stopped by the compression of the cylinder B during the working phase. Before the reverse movement and / or during the reverse movement, the original working cylinder B is injected one or more times. Just before reaching the top dead center ZOT for cylinder B, the gas mixture that is precompressed is ignited by an ignition plug 9 in the cylinder. The internal combustion engine 1 is started in the forward direction (middle of the drawing) by the ignition and the combustion caused thereby and the combustion chamber pressure based thereon. This forward movement is braked by the formation of a compression pressure in the first starter cylinder A. In this case, a pressure reducing valve (Dekompressionsventil) 15 is arranged in the cylinder A, and this pressure reducing valve 15 is a second valve during forward movement. Stage (center), thereby reducing the pressure and thus facilitating movement on the basis of the reduced damping.

  The pressure reducing valve 15 is opened in the compression stage, and after the top dead center position is obtained at the earliest, the pressure reducing valve 15 is closed together with the closing of the associated exhaust valve at the latest.

  In this case, the third stage is forward rotation without ignition. Alternatively, however, injection may be carried out into the cylinder A that reaches the third stage working stroke. In this case, the pressure reducing valve is closed again as appropriate so that the braking action in the cylinder is reduced and sufficient supply is provided for subsequent combustion.

  FIG. 3 shows another embodiment of this method. In this case, the pressure reducing valve 15 is arranged in the first working cylinder B. Furthermore, FIG. 3 shows a cylinder C, which is initially in the exhaust stroke in the first stage (left side of the drawing), in which case the valve 5 with the exhaust pipe 7 is opened. .

In Figure 3, similarly to FIG. 2, the backward movement due to combustion in the cylinder A, the cylinder C moves to its working stroke again. By the backward movement, compression is performed in the cylinder C, and the backward movement is stopped before reaching the top dead center of the cylinder C by the compression. On the other hand, in order to reduce the backward rotation, the pressure reducing valve 15 in the cylinder B is opened. A single injection or multiple injections are performed in the cylinder C via the injection valve 8. This is done as soon as the exhaust valve 5 is closed at the time of transition from the exhaust stroke to the working stroke. Immediately before reaching ZOT, the precompressed air-fuel mixture is ignited by the spark plug 9, and the internal combustion engine 1 is started in the forward direction (stage 2, center of the drawing) by the increased combustion chamber pressure. During the forward rotation of the internal combustion engine, the pressure reducing valve 15 is further opened and then closed in a predetermined manner, whereby the braking action in the cylinder B is reduced on the basis of the compression pressure formation in the cylinder B, however. On the other hand, when the transition is made to the working stroke again during phase 3 (right side of the drawing), sufficient supply is ensured for the subsequent combustion in cylinder B.

  FIG. 4 shows another alternative embodiment, in which, in addition to cylinders A and B, cylinder D is shown, which is stage 1 (drawing) during the intake stroke. Is on the left).

In this case, similarly to FIG. 2, the starting is performed with the backward rotation. However, in the embodiment shown in FIG. 4, the cylinder A is not provided with a pressure reducing valve, and no forward rotation is performed in stage 2. The forward movement of the internal combustion engine 1 is performed by starting combustion in the cylinder B, as shown in FIG. This cylinder B is in the working stroke of the first stage (left side of the drawing), during which the cylinder B is brought to the starting position just before the ZOT. Further, as soon as the cylinder D reaches the compression stroke illustrated in stage 3 (third from the left in the drawing), the pressure reducing valve 15 in the intake cylinder, that is, the cylinder D is operated. Here, as in FIG. 3, the braking action in the cylinder D is reduced on the one hand, but on the other hand sufficient charge for combustion in the cylinder D during the subsequent stage 4 (right side of the drawing). The pressure reducing valve 15 is closed during the compression stroke.

  In FIG. 5, a pressure reducing valve is provided on the one hand in the compression cylinder A and on the other hand in the intake cylinder D. In this case, the pressure reducing valve 15 in the compression cylinder A is opened during the compression phase of the cylinder A at the start of forward movement in order to reduce the damping (see FIG. 2). In the next stage 3, the nominal pressure valve 15 in the cylinder D is opened, thereby reducing the braking action based on the generated compression pressure (see FIG. 2). In this case, in the two cylinders A and D, it is necessary to operate the pressure reducing valve 15 so that the compression pressure formation is reduced on the one hand and sufficient air is supplied into the cylinder for the subsequent combustion on the other hand. There is.

  Furthermore, in addition, a pressure reducing valve (not shown) may be provided in the exhaust cylinder C. The pressure reducing valve is opened as soon as the cylinder shifts to its compression stroke compression stroke via the air supply stroke after the forward movement of the internal combustion engine 1. As a result, the braking action is reduced again, and a sufficient number of revolutions of the internal combustion engine 1 (guaranteed reliable high revolution) can be reached as soon as possible. In this case, the control of the pressure reducing valve in the exhaust cylinder is performed as described above.

  In the starting method according to the present invention, four pressure reducing valves may be provided. In this case, in addition, the pressure reducing valve in the working cylinder is operated as shown in FIG. 3 as soon as the cylinder shifts to its compression stroke once during the forward rotation of the internal combustion engine 1.

  FIG. 6 shows a method with two pressure reducing valves 15 in the compression cylinder A and in the working cylinder B. This method is otherwise performed as described for FIG. In this case, the first ignition for the forward movement of the internal combustion engine 1 in the cylinder C in the starting stage (left side of the drawing) during the exhaust stroke is performed. Next, during the forward rotation, first, the pressure reducing valve 15 in the cylinder B is operated. This takes place during the second phase when the first cylinder B in the working stroke enters the compression phase. In this case, the pressure reducing valve 15 is controlled and opened in such a way that sufficient air supply is provided for ignition in the cylinder B which takes place during stage 3, although the braking action of the compression pressure is reduced. As previously mentioned, it is injected into cylinder B during compression and then ignited during stage 3 (right side of the drawing) in this cylinder B for another forward rotation. Then, during this stage, the pressure reducing valve in cylinder A is opened, while cylinder C is in the exhaust stage. Furthermore, the pressure reducing valve in the cylinder B is also opened by reverse rotation while setting the start position.

  FIG. 7 shows a configuration in which three pressure reducing valves are provided in the compression cylinder A, the working cylinder B, and the intake cylinder D. In this case, the starting method is performed in accordance with the description relating to FIG. In this case, in addition to the pressure reducing valve 15 in the cylinder A opened in the second stage and the pressure reducing valve 15 in the cylinder D opened in the third stage, a pressure reducing valve can be provided in the cylinder B. The pressure reducing valve is opened during forward rotation during the fourth stage.

  Then, optionally, also in the method shown in FIG. 7, a fourth pressure reducing valve is provided, and this fourth pressure reducing valve has its compression stroke first when the internal combustion engine 1 rotates forward. As soon as the transition is made, it is operated in the exhaust cylinder.

  In all methods, the built-in pressure reducing valve 15 is used in order to obtain a full development of the power of the internal combustion engine 1 for the driving operation of the motor vehicle after reaching a predetermined lower limit rotational speed. Maintained closed.

  Finally, the first return rotation is always developed indicating that it is in the first stage. In this case, ignition for starting is performed not in the compression cylinder A but in the working cylinder, and in this case, when ignited in the working cylinder B, the engine starts without returning and rotating. Again, one or more pressure reducing valves are used, and in this case also the above description applies to control the pressure reducing valves.

1 is a schematic view of an internal combustion engine of a motor vehicle according to an advantageous embodiment of the invention; FIG. It is the schematic which shows the 1st embodiment of this invention for starting the internal combustion engine shown in FIG. FIG. 2 is a schematic diagram showing an alternative embodiment of the method according to the invention for starting the internal combustion engine shown in FIG. 1. FIG. 2 is a schematic diagram showing an alternative embodiment of the method according to the invention for starting the internal combustion engine shown in FIG. 1. FIG. 3 is a schematic diagram illustrating another alternative embodiment of the present invention. FIG. 3 is a schematic diagram illustrating another alternative embodiment of the present invention. FIG. 6 is a schematic diagram illustrating yet another embodiment of the method of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Internal combustion engine, 2 Piston, 3 Cylinder, 4 Combustion chamber, 5 Valve, 6 Intake pipe, 7 Exhaust pipe, 8 Injection valve, 9 Spark plug, 10 Crankshaft, 11 Rotational speed sensor, 12 Control apparatus, 13 Accelerator pedal sensor , 15 Pressure reducing valve

Claims (8)

A method for starting a gasoline direct injection multi-cylinder internal combustion engine of an automobile, wherein when a start-up process is required, the position of at least one piston in at least one cylinder arranged corresponding to the piston is detected. The fuel is injected into the cylinder or cylinders in which the piston is in the working stroke, at which time the fuel and gas mixture in at least one cylinder in the working stroke is ignited. In a method in which the piston or pistons transition the pistons of the other cylinders into a forward motion that carries out a working stroke via a crankshaft connecting these pistons,
Opens the reducing valve provided in at least the one further cylinder during the compression stroke, whereby the resistance to motion of the piston reduces, and injected into the at least one cylinder in front of the top dead center in the compression stroke, By igniting the generated air-fuel mixture, the piston is moved to a starting position after top dead center before being injected into at least one cylinder during the working stroke, thereby what is said working stroke motion of the piston? The reverse movement causes a reverse movement that causes the piston of at least one other cylinder to move to the starting position during the working stroke and at the same time compresses the gas in the cylinder and causes the pressure reducing valve to move in the at least one cylinder. The resistance is reduced, but enough gas remains for combustion during the next working stroke. And controlling, method for starting a multi-cylinder internal combustion engine. In at least one of the same cylinder, at least one of the pressure reducing valve, even during also the forward movement in the backward movement, to open in order to reduce the resistance, the method of claim 1. 3. A method according to claim 1 or 2 , wherein the pressure reducing valves are opened one after the other during the forward movement of the internal combustion engine in each cylinder in the compression stroke. Performing multiple injections, any one process of claim 1 to 3. After reaching a predetermined speed, pressure reducing valve from being operated more, any one process of claim 1 to 4. A computer program for implementing the method of any one of claims 1 to 5, is a file in the memory, and characterized in that it is a computer executable computer program. Control and / or regulation device for an internal combustion engine of a motor vehicle, characterized in that the control and / or regulation device (12) has a memory in which the computer program according to claim 6 is stored. Control and / or regulating device for an internal combustion engine of a motor vehicle. An internal combustion engine having a plurality of cylinders (2) of a motor vehicle for carrying out the method according to any one of claims 1 to 5 , wherein the internal combustion engine (1) is a part of the internal combustion engine (1). A detection device (11) for detecting the position of at least one piston (2) in the cylinder (3) and of at least one cylinder (3) in which the piston (2) is in a working stroke and / or a compression stroke; In the type having a fuel metering system (8) for injecting fuel into the combustion chamber (4),
At least one pressure-reducing valve (15) for reducing the resistance of the at least one cylinder (3) brought to the compression stroke after ignition of the fuel / gas mixture in the at least one cylinder (3) during the working stroke ), Whereby the internal combustion engine (1) can be started directly without a starter.

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