JP2013015136A - Supercharging pressure regulating method for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method, which optimizes an exhaust gas state and the like of a pressure wave supercharger with respect to an internal combustion engine, and which is applicable to mass production.SOLUTION: In a supercharging pressure regulating method for the internal combustion engine A for which a supercharging pressure is boosted by a pressure wave supercharger B, and to the pressure wave supercharger B, a first pipe 1 for introducing outside air, a second pipe 2 for guiding a compressed air, a third pipe 3 for supplying exhaust gas, and a fourth pipe 4 for discharging exhaust gas are connected, the pressure wave supercharger B has a low temperature air casing connected to the first pipe 1 and the second pipe 2, and an exhaust gas bypass valve F disposed near the third pipe 3, and a regulating element D is provided for regulating a cross-sectional area of a pipe opening, in the low temperature air casing, the position of the regulating element D is controlled according to a difference between an actual measured value and a target value of the opening of the exhaust gas bypass valve F.

Description

  The present invention relates to a method for adjusting the supercharging pressure of an internal combustion engine based on the features of the premise part of claim 1.

  It has been conventionally known to supercharge an internal combustion engine in order to obtain a larger output with the same in-cylinder volume or to obtain a similar output while reducing the in-cylinder volume. Here, the introduced outside air is compressed by the compressor and then supplied to the combustion process. As types of compressors, turbochargers, compressors, pressure wave superchargers and the like are conventionally known.

  In recent years, when a pressure wave supercharger is used, it is possible to make the pressure wave supercharger correspond to each operating point of the internal combustion engine by using a preset reference value with an active parameter (aktiv). As a result, optimization at each operating point of the supercharged internal combustion engine and high efficiency and / or good and quick response characteristics associated therewith can be obtained.

  As a whole, the direct contact between the outside air and the exhaust gas is a major drawback, but it can be minimized in the pressure wave supercharger. For this reason, this pressure wave supercharger has attracted attention as an alternative to a turbocharger or a compressor, particularly with respect to the recent demand for engine size reduction. Further, a conventionally known control model is based on static changes in each operation parameter transferred to an actuator by a control device based on a measured value by a sensor, a calculation model, or a stored characteristic curve.

  Patent Document 1 discloses an operation method of an internal combustion engine, in which outside air is compressed by a pressure wave supercharger, and at least one operation parameter in the pressure wave supercharger is converted into at least one actually measured value in the internal combustion engine. It is controlled accordingly. In this respect, the method disclosed in Patent Document 1 is different from the conventional control concept of a pressure wave supercharger that is not flexible and is not controlled.

  By adapting each operating state of the pressure wave supercharger to the operating state of the internal combustion engine, the pump loss of the internal combustion engine can be minimized. In addition, by doing so, the response characteristics of the pressure wave supercharger and the internal combustion engine are improved, and the conditions of the exhaust gas aftertreatment are optimized.

  Patent Document 2 discloses a pressure wave supercharger, in which a diversion is made from an exhaust gas supply pipe to an exhaust gas bypass, and such a diversion is performed by an exhaust gas bypass valve in accordance with a supercharging pressure. To be controlled. The exhaust gas bypass valve itself is controlled via a control line. In addition, the inflow to the exhaust gas bypass prevents gas from being blown from the high-pressure pipe to the outside air (ambient) by opening the inlet to the exhaust gas bypass with an elastic member in a stopped state and during an emergency operation of the internal combustion engine. It has become.

  Patent Document 3 also discloses a pressure wave supercharger, and a rotatable low-temperature casing is provided to improve the operating state of the pressure wave supercharger and the internal combustion engine. The rotatable low-temperature casing is controlled during the operation of the pressure wave supercharger in order to improve the operation of the pressure wave supercharger by a characteristic curve region common to the internal combustion engine.

German Patent Application No. 102006020522 German Patent Application No. 4034341 German Patent Application Publication No. 69823039

  However, the pressure wave supercharger control method according to the prior art requires a large number of sensors and control devices, and is not suitable for mass production in small vehicles. In addition, a sensor that is used in a multiple manner tends to cause a failure. Furthermore, the use of overlapping sensor systems results in significant production costs and maintenance costs.

  In addition, the pressure difference between the intake and exhaust ducts creates a hydrodynamic process in the pressure wave supercharger rotor cell, which creates almost innumerable thermodynamic state quantities. Become. Such countless state quantities can often only be calculated by very long and complex numerical equations, so detailed modeling of a pressure wave supercharger that can be performed by a controller is not possible with today's CAE. is there.

  The present invention has been made in view of the above problems, and its object is to optimize the exhaust gas state, response characteristics, durability and efficiency of the pressure wave supercharger with respect to the internal combustion engine as much as possible. The object is to provide a pressure wave supercharger control method that can be applied to mass production without being influenced by factors.

  This object is achieved by a method having the features set forth in claim 1. Moreover, other embodiments of the method according to the invention are part of each dependent claim.

  The supercharging pressure is increased by a pressure wave supercharger including a cell rotor and a cell rotor casing, and the pressure wave supercharger has a first pipe 1 for introducing outside air, and a guide for the compressed air. A second pipe 2, a third pipe 3 for supplying exhaust gas, and a fourth pipe 4 for discharging exhaust gas are connected, and the pressure wave supercharger is connected to the first pipe 1 and the first pipe. 2 includes a low-temperature air casing connected to the pipe 2 and an exhaust gas bypass valve disposed in the vicinity of the third pipe 3, and an adjustment for adjusting the cross-sectional area of the pipe opening in the low-temperature air casing The method of adjusting the supercharging pressure of an internal combustion engine according to the present invention in which an element is provided, the position of the adjusting element is set to open the exhaust gas bypass valve. It is characterized by controlling in accordance with the difference between the measured value and the target value of.

  In the present invention, the adjustment element is a rotatable casing, an adjustment element, an edge slider (Kantenschieber) or a control roller. In addition, this control roller makes the intake port or the exhaust port variable by a geometric shift between the third pipe 3 and the fourth pipe 4 and the first pipe 1 and the second pipe 2. In the present invention, the adjustment element is preferably disposed on the low temperature side of the pressure wave supercharger, but may be disposed on the high temperature side.

  In the present invention, the exhaust gas bypass valve disposed in the vicinity of the third pipe 3 is a blow-by valve that controls the gas flow rate in the pipe 3 ′. The pipe 3 ′ is in contact with the pipe 3 and extends into the rotor cell of the cell rotor. The pipe 3 'can be variably opened in the range of 0 to 100% by the exhaust gas bypass valve. In the present invention, the exhaust gas bypass valve may form a direct bypass between the third pipe 3 and the fourth pipe 4. Furthermore, it is conceivable that the opening degree of the bypass from the third pipe 3 to the fourth pipe 4 is variably controlled by the exhaust gas bypass valve.

  For this reason, the method according to the present invention provides a solution for optimal and dynamic adjustment of the engine operating state based on the energy change occurring in the third pipe 3. In the dynamic control process, the demand for the supercharging pressure target value changes clearly (vordergruendig). The supercharging pressure target value is controlled by the opening (position) of the exhaust gas bypass valve. Further, an energy impulse is generated in the third pipe 3 in the pressure wave supercharger by changing the opening of the exhaust gas bypass valve. And this energy change acts on the cell of a cell rotor, and also acts on the air which should be compressed, or compressed air. Moreover, in order to prevent the exhaust gas leakage from the 3rd piping 3 to the 2nd piping 2, an adjustment element is adjusted with the correction value according to the opening degree change of the exhaust gas bypass valve. In particular, the relative value of the difference in the exhaust gas bypass valve opening is analyzed as the control amount, and the correction value is generated as the relative value as the control signal.

  In the dynamisch control method for changing the position of the adjustment element, the rotational speed of the internal combustion engine is an important input value. Here, it is first important to grasp the actual position of the adjustment element. In particular, in the present invention, the actual position is determined from the maximum value and the minimum value according to the measured value of the boost pressure and the characteristic curve of the rotational speed of the internal combustion engine. Between these maximum and minimum values, the optimum position of the adjustment element or the correction position of this adjustment element is calculated based on the difference between the opening of the exhaust gas bypass valve and the rotational speed of the internal combustion engine.

  By limiting the maximum and minimum values for the position of the adjustment element, it is possible to prevent exhaust gas leakage and the adjustment element from reaching the wrong position. Further, such prevention works optimally on the exhaust gas state and response characteristics of the entire internal combustion engine.

  The dynamic supercharging pressure control according to the present invention can be performed in an open loop or a closed loop. Thereby, it is possible to obtain very quick control characteristics and response characteristics while suppressing the cost of hardware and software for control.

  The relative adjustment of the exhaust gas bypass valve is a relative adjustment between the measured value of the opening degree of the exhaust gas bypass valve and the target value obtained from the characteristic curve. The optimum opening degree (position) of the exhaust gas bypass valve is an opening degree (position) that exhibits the maximum efficiency in the interaction between the internal combustion engine and the pressure wave supercharger. The difference or relative adjustment of the exhaust gas bypass valve is one value with respect to the calculated or obtained optimum opening (position), and this value indicates how optimal the pressure wave supercharger operates. For this reason, the relative value is grasped as a control amount for the optimization of the pressure wave process. When the optimum operation opening (position) is obtained, the control amount for the relative adjustment of the exhaust gas bypass valve becomes substantially zero, and the correction values for the other adjustment elements become substantially zero. The control time for this control process is in the range of 5-10 ms.

  In the present invention, the relative engine output is defined as follows. That is, the target engine output is divided by the maximum engine output and multiplied by 100%. Thereby, the relative engine output shown as a percentage of the maximum engine output is obtained. In particular, it is preferable to always look at the relative engine output for the engine speed. For the characteristic curve showing the output with respect to the rotational speed, the relative engine output should always be on the vertical axis with respect to the rotational speed region. In addition, since the control process is dynamically executed, first, a specific rotational speed about the vertical axis is detected. However, since the increase or decrease of the rotational speed is taken into account by the control time interval, The process is considered dynamic based on precise control.

  In the present invention, the control can be performed by a relative load. Here, the relative load is, for example, a target load determined by the accelerator pedal depression position divided by the maximum load and multiplied by 100%.

  In the present invention, the internal combustion engine torque characteristic is a strategy that is the basis of engine management control. The overall control of the internal combustion engine is performed with respect to torque in units of Nm (Newton meter). In such a case, the target value and actual measurement value in the control are expressed in units of Nm. Therefore, the internal combustion engine torque characteristic curve functions in units of Nm, but may function on the basis of relative load. Each internal combustion engine torque characteristic curve is unique to each manufacturer depending on the control device used for the internal combustion engine.

  Moreover, one embodiment of the present invention is characterized in that the rotational speed of the cell rotor is adjusted and / or controlled according to the opening degree of the exhaust gas bypass valve. Here, the rotational speed of the cell rotor means the rotational speed of the pressure wave supercharger. In particular, it is desirable to adjust the pressure wave supercharger by driving it with a unique motor and changing the number of rotations accordingly. Further, it is particularly preferable to control the rotation speed of the pressure wave supercharger by an absolute value and / or a relative correction value by a difference in the exhaust gas bypass valve opening, that is, by relative adjustment of the exhaust gas bypass valve. In particular, the rotation speed of the cell rotor is controlled in combination with the adjustment of the position of the adjustment element.

  Moreover, in the dynamic adjustment method of the supercharging pressure by the rotation speed of the cell rotor, the rotation speed is limited. Such a limit is determined according to the measured value of the boost pressure and the rotational speed of the internal combustion engine. Furthermore, it is possible to additionally determine the maximum value and the minimum value of the rotational speed of the pressure wave supercharger for restriction.

  In particular, the measured value of the boost pressure and the rotational speed of the internal combustion engine are determined by the parameters as described above, the upper limit value and the lower limit value are determined by the characteristic curve, and a correction value between them is calculated. The value calculated in this way for the target rotation speed of the pressure wave supercharger is input as a correction value to the rotation speed controller of the pressure wave supercharger.

  According to the present invention, the exhaust wave state, response characteristics, durability and efficiency of the pressure wave supercharger are optimized for the internal combustion engine, and can be applied to mass production without being affected by external factors as much as possible. It is possible to provide a control method for the pressure wave supercharger. Other advantages, features, etc. of the present invention will be described below.

It is a figure which shows the outline | summary of the circulation path of the intake air which leads to exhaust gas piping through an internal combustion engine. It is a flowchart of the dynamic control of the position of an adjustment element. It is a graph which shows a characteristic curve.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a part of an internal combustion engine A formed as a gasoline engine in the present embodiment. Further, the pressure wave supercharger B includes four pipes 1 to 4 (first pipe to fourth pipe) coupled to the pressure wave supercharger B. Here, the pipe 1 is located in the intake (outside air) region, and the pipe 2 is arranged in the compressed intake region where the compressed intake air is supplied to the intercooler J and further to the throttle valve K connected thereto. Yes. The compressed intake air is supplied to the combustion chamber 10 after passing through the throttle valve K.

  Further, in order to supply exhaust gas to the pressure wave supercharger B, a pipe line 3 is arranged between the exhaust valve 6 and the catalyzer before (upstream) the pressure wave supercharger B. Further, an exhaust gas bypass valve (Gastaschenventil) F provided with an actuator is disposed in the pipe 3. In the area of the exhaust gas pipe S, the pressure wave supercharger B is provided with a pipe line 4 for discharging the exhaust gas after the compression process in the pressure wave supercharger B. The conduit 4 is provided with an oxidation catalytic converter M.

  FIG. 1 further shows a cross section of the cylinder, in which an intake valve 5, an exhaust valve 6, a piston 7, a spark plug 8, a fuel injection nozzle 9 and a combustion chamber 10 are shown. In addition, a pressure wave supercharger B is coupled to the internal combustion engine A.

  Thus, the pressure wave supercharger B is further provided with a low-temperature casing side (low-temperature air casing) 11 and a high-temperature casing side 12, and an adjustment element D is arranged on the low-temperature casing side 11. The adjusting element D is controlled by a motor (Steuerscheibenstellmotor), and the rotor C arranged in the pressure wave supercharger B is controlled by a motor (elektrischer Rotormotor) E.

  Then, the intake air passes through the pipe 1 and is introduced into the rotor cell 13 following the pipe 1 and is compressed in the pressure wave supercharger B. Thereafter, the compressed air is introduced into the intake valve 5 near the outlet of the pipe 2 through the pipe 2. Here, a bypass valve provided with an actuator is interposed in the pipe 2 so that the intercooler J and the combustion chamber 10 are swirled through the bypass pipe. Further, in the intercooler J, the compressed and heated air is cooled, and its volume is reduced. Thereby, the filling efficiency of the cylinder in the combustion chamber 10 is improved.

  In addition, the intake timing according to the compression timing (cycle) is adapted to the combustion timing and the exhaust timing in the example of the four-cycle engine. In the present invention, it is possible to apply an engine of another cycle.

  The exhaust gas formed in the combustion chamber 10 in the exhaust process is again introduced to the high temperature side through the pipe 3. Here, a catalyzer L that performs primary exhaust gas post-treatment is interposed in the pipe 3. Also, the pipe 3 ′ can be driven by an actuator to increase the inflow of residual gas into the rotor cell 13 via the intake port of the pipe 3 ′ and / or the exhaust gas can be directly piped through the rotor. An exhaust gas bypass valve F for guiding to 4 is arranged. In the present invention, the exhaust gas can be directly guided from the pipe 3 ′ to the pipe 4 through the exhaust gas bypass valve F.

  Thus, the outside air introduced through the pipe 1 is compressed by the pressure wave, and the pressure wave causes the compressed air to flow through the pipe 2, and further, this air passes through the exhaust port of the rotor cell 13 to the exhaust gas pipe S. It has become something to be achieved. In some cases, the exhaust gas passes through other exhaust gas post-treatment means such as an oxidation catalytic converter M.

  By the way, FIG. 1 further shows a plurality of measurement points, and these measurement points indicate locations where necessary operating parameters (Betriebsgroesse) are measured. Pos. 1 is a measurement point in the outside air inlet region. 2-US is a measurement point of the compressed air region before the intercooler J. In addition, Pos. 2-DS is a measurement point after the throttle valve K (downstream) and before the intake valve 5 of the internal combustion engine A. Pos. 3-US is a measurement point at an arbitrary location in the pipe 3. Furthermore, Pos. 3-DS is a measurement point before the inlet to the pressure wave supercharger B. Here, the measurement point Pos. 3-US and Pos. 3-DS is for measuring the total flow rate after or before the bypass valve H and the exhaust gas bypass valve F, respectively, and the measurement data is used for opening control of the bypass valve H and the exhaust gas bypass valve F. It is intended to be used.

  In addition, Pos. 4 is an arbitrary measurement point in the pipe 4 after the pressure wave supercharger B. Each of the above measurement points is a preferred example, and these measurement points may be further added or reduced depending on the application form. Further, the position of the measurement point can be freely selected.

  Below, the table | surface regarding description of the control flowchart in FIG. 2 is shown.

FIG. 3 schematically shows an example of a characteristic curve of the internal combustion engine, and this characteristic curve also schematically shows how the relative engine output can be obtained. First, in the graph showing this characteristic curve, the Y axis (vertical axis) is the engine output expressed in units of kW (kilowatt), and the X axis (horizontal axis) indicates the engine speed (rpm) per minute. Yes.
If it is at an operation point of 4000 revolutions per minute, a target engine output is required depending on the accelerator pedal depression position, and a target operation point indicated by a point “W” in FIG. 3 is obtained. On the other hand, in the preload curve V, the maximum engine output obtained at the operating point of 4000 revolutions per minute is indicated by a point “M”. Here, when the target engine output is divided by the maximum engine output and multiplied by 100, the relative engine output is obtained in%. The formula is as follows.

1-4 Piping 5 Intake valve 6 Exhaust valve 7 Piston 8 Spark plug 9 Fuel injection nozzle 10 Combustion chamber 11 Low temperature casing side 12 High temperature casing side 13 Rotor cell A Internal combustion engine B Pressure wave supercharger C Rotor D Adjustment element E Motor F Exhaust gas bypass Valve H Bypass valve J Intercooler K Throttle valve L Catalyzer M Oxidation catalytic converter S Exhaust gas piping V Preload curve Pos. 1 Measurement point Pos. 2-US measuring point Pos. 2-DS measurement point Pos. 3-US measuring point Pos. 3-DS measurement point Pos. 4 measuring points

Claims (9)

A method for adjusting a supercharging pressure of an internal combustion engine (A), wherein the supercharging pressure is increased by a pressure wave supercharger (B) including a cell rotor (C) and a cell rotor casing, and the pressure wave supercharger (B). The first pipe (1) for introducing the outside air, the second pipe (2) for guiding the compressed outside air, the third pipe (3) for supplying the exhaust gas, and the exhaust gas A low-temperature air casing connected to the fourth pipe (4) for discharging, and the pressure wave supercharger (B) connected to the first pipe (1) and the second pipe (2); And an exhaust gas bypass valve (F) disposed in the vicinity of the third pipe (3), and an adjustment element (D) for adjusting the cross-sectional area of the pipe opening is provided in the low-temperature air casing. In said boost pressure control method for an internal combustion engine (A) being kicked,
The supercharging pressure adjustment method characterized by controlling the position of the said adjustment element (D) according to the difference of the measured value of the opening degree of the said exhaust gas bypass valve, and a target value.   The actual position of the adjusting element (D) is limited, and the actual position is determined based on the actual measured value of the boost pressure, the relative engine output, the internal combustion engine-torque characteristics (Verbrennungsmotor-Drehmomenten-Struktur) and the internal combustion engine (A). 2. The supercharging pressure adjustment method according to claim 1, wherein it is determined according to at least one of the rotational speeds.   In order to calculate the actual position of the adjustment element (D), among the measured value of the boost pressure, the relative engine output, the internal combustion engine-torque characteristics (Verbrennungsmotor-Drehmomenten-Struktur) and the rotational speed of the internal combustion engine (A) The supercharging pressure adjustment method according to claim 1 or 2, wherein a characteristic curve (Kennfeldstruktur) is analyzed according to at least one of them.   In order to control the position of the adjusting element, the maximum value and / or the minimum value with respect to the position are determined from the actual measured value of the boost pressure, the relative engine output, the internal combustion engine-torque characteristics (Verbrennungsmotor-Drehmomenten-Struktur) and the internal combustion engine. The supercharging pressure adjustment method according to any one of claims 1 to 3, wherein the calculation is performed according to at least one of the rotational speeds of (A).   The supercharging pressure adjustment method according to any one of claims 1 to 4, wherein the rotational speed of the cell rotor (C) is adjusted and / or controlled in accordance with an opening of the exhaust gas bypass valve.   The rotational speed is limited, and the rotational speed is at least one of a measured value of boost pressure, a relative engine output, an internal combustion engine-torque characteristic (Verbrennungsmotor-Drehmomenten-Struktur), and a rotational speed of the internal combustion engine (A). The supercharging pressure adjustment method according to claim 5, wherein the supercharging pressure adjustment method is determined according to whether   In order to calculate the rotational speed, it depends on at least one of an actual measured value of boost pressure, a relative engine output, an internal combustion engine-torque characteristic (Verbrennungsmotor-Drehmomenten-Struktur), and a rotational speed of the internal combustion engine (A). The method for adjusting the supercharging pressure according to claim 5 or 6, wherein a characteristic curve (Kennfeldstruktur) is analyzed.   In order to control the rotational speed, the maximum value and / or the minimum value with respect to the position are measured values of boost pressure, relative engine output, internal combustion engine-torque characteristics (Verbrennungsmotor-Drehmomenten-Struktur) and internal combustion engine (A 8) The supercharging pressure adjustment method according to any one of claims 5 to 7, characterized in that the calculation is performed according to at least one of the rotation speeds.   The supercharging according to any one of claims 5 to 8, wherein the position of the adjustment element (D) and / or the rotational speed is controlled in accordance with the rotational speed of the internal combustion engine (A). Pressure adjustment method.

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