• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
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    • 专利摘要:
    The subject of the present invention is a method of starting a direct injection internal combustion engine of a vehicle, making it possible to accelerate the starting phase by adjusting the quantity of fuel injected during this starting phase, before the set speed of the Engine, consisting of the following steps: • Turn the high-pressure injection pump by means of a starter, • Measure the pressure of the fuel delivered by the pump, taken at two successive high compression dead points of the pump operating in operating mode. maximum flow, • Establish the fuel pressure gradient, on an angular reference, on the basis of the pressure measured at the two successive high compression dead points of the pump characterized by their angular positions, • Compare the established gradient with a one-to-one table predetermined manner respectively matching a plurality of fuel quantities to be injected and a plurality pressure gradients, • Adapt the amount of fuel injected during the engine start-up phase, depending on the result of the comparison, in order to inject a quantity of fuel which corresponds, in the predetermined one-to-one table, to the gradient of pressure established, as soon as an authorization of the first injection given by the engine control unit.
    公开号:FR3028891A1
    申请号:FR1560858
    申请日:2015-11-13
    公开日:2016-05-27
    发明作者:Claude Courtiel；Philippe Serrecchia；Renaud Andre
    申请人:Continental Automotive GmbH；Continental Automotive France SAS；
    IPC主号:
    专利说明:

    [0001] The present invention relates to a method of starting a direct injection internal combustion engine of a vehicle, for accelerating the start-up phase by adjusting the quantity of fuel injected, during this start-up phase, before starting. of the engine, by means of an injection system comprising a high-pressure fuel injection pump. The quantity of fuel to be injected during the starting phase of such an engine is dependent on the engine temperature, the number of high dead points passed by the crankshaft before the established speed, the engine speed during this starting phase, and also the quality and type of fuel used, present in the fuel tank, which may have been learned or recognized during a previous driving cycle of the vehicle. When starting after filling the tank with a fuel whose characteristics have evolved with respect to the fuel contained prior to said filling, the lack of precision of the quantity of fuel to be injected at startup 15 can generate longer start times or no starts. Document DE102011077404 is known which proposes a method of recognizing the type of fuel before starting the engine so as to adapt accordingly the dosage of the injected quantities of fuel before the injection. Such a method has the advantage of optimizing the efficiency of the engine and preventing the injection of an inappropriate fuel into the engine as a result of a fuel error for example. The method according to this document is to compare the curve of rise in pressure in the rail as a function of time (dP / dt) with curves recorded in the ECU (for "Engine Control Unit" in English), and thus to determine the type or quality of fuel present in the rail before injection. The method uses the determination of the Young's modulus of the fuel. The amount of fuel injected can thus be adjusted according to the type or quality of fuel detected. An advantage of this method is that it allows the determination of the type of fuel before combustion, thus improving the combustion efficiency. The present invention proposes to increase the starting speed of a direct injection internal combustion engine, irrespective of the fuel present in the tank. More specifically, the invention consists in a method of starting a direct injection internal combustion engine of a vehicle, making it possible to accelerate the starting phase by adjusting the quantity of fuel injected during this starting phase, before engine speed, by means of an injection system 3028891 2 comprising a high-pressure fuel injection pump, means for measuring the pressure delivered by the latter, and an engine control unit or ECU, characterized in that that said method comprises the following steps: - Turning the high-pressure injection pump by means of a starter, 5 - Measuring the pressure of the fuel delivered by said high-pressure injection pump, taken at least two high compression dead points of the pump operating in maximum flow mode, - Establish the pressure gradient, on an angular reference, of the fuel delivered by the pump high pressure injection, based on the pressure measured at said at least two successive high compression dead points of the high-pressure injection pump characterized by their angular positions, - comparing said established gradient with at least one predetermined one-to-one array matching respectively a plurality of quantities of fuel to be injected and a plurality of said pressure gradients, said at least one table being implemented in the engine control unit, - Adapting the quantity of fuel injected during the start-up phase of the engine , according to the result of the comparison, in order to inject a quantity of fuel which corresponds, in the predetermined one-to-one table, to the established pressure gradient, as soon as authorization of the first injection given by the engine control unit is given. The invention consists in detecting a specific gradient of rise in pressure of the fuel delivered by the high pressure pump, based on the high dead points of compression of the pump operating in maximum flow mode, in order to optimize the accuracy as quickly as possible. of this specific gradient and the result obtained of the correct amount of fuel to be injected during the startup phase, by injection. According to the invention, the pressure gradient is established relative to an angular reference system (high compression dead points of the pump characterized by their angular positions), which advantageously eliminates the rotation speed of the starter which can vary especially with temperature and battery voltage. The predetermined one-to-one table provides directly from the pressure rise gradient the correct amount of fuel to be injected, for example for a given temperature range. Thus, the amount of fuel to be injected can be adjusted with great accuracy before or as soon as the first combustions during the starting phase depending on the type of fuel present in the injection system. An authorization of the first injection is given by the engine control unit for example as soon as the synchronization of the engine has been performed and as soon as the minimum injection pressure has been reached. The means for measuring the pressure are, for example, provided in a known manner by a pressure sensor present in an injection system, for example in a high-pressure rail-type accumulator. According to an advantageous characteristic: said at least one one-to-one array corresponding respectively a plurality of quantities of fuel to be injected and a plurality of pressure gradients is predetermined for a given range of engine temperatures, a plurality of said predetermined one-to-one arrays are implemented in the engine control unit, covering a plurality of engine temperature ranges, respectively, having at least one cold start temperature range, - said method further comprising measuring the engine temperature before comparing said gradient established with said at least one predetermined one-to-one array. By the term "predetermined one-to-one array for a given range of engine temperatures" is meant here a given range of temperatures for which the one-to-one table applies. This given temperature range can be reduced to a single temperature for which the one-to-one table has been defined, if it is desired to restrict to this single temperature the values of said one-to-one table. Such a choice depends on the degree of precision which it is desired to achieve for the quantities of fuel to be injected as a function of the temperatures. So that, if the one-to-one table is valid for a given range of temperatures around said single temperature value for which it has been defined, given the accuracy to be achieved, the application of said table can be extended to this range. engine temperature data. According to an advantageous characteristic, the position of said at least two successive high compression dead points of the fuel injection pump is determined by means of a crankshaft position sensor of the engine, a law of connection of the angular positions. between the crankshaft and the high-pressure fuel injection pump, and the engine control unit. According to an advantageous characteristic, the pressure gradient is established with respect to a variation of the angular position of the high pressure injection pump, in the form dp / da with: the pressure variation between the at least two dead spots; successive compression stages of the pump, - the angular variation of the crankshaft between said at least two successive high compression points of the pump.
    [0002] This characteristic notably illustrates the fact of advantageously avoiding the speed of rotation of the starter in the calculation of the pressure gradient. According to an advantageous characteristic, the pressure gradient of the fuel delivered by said high-pressure injection pump is established with three high compression dead points of the high-pressure injection pump, or more. The invention furthermore relates to a starting device for a direct injection internal combustion engine for accelerating the starting phase by adjusting the quantity of fuel injected during this starting phase before the engine is set at a steady speed. injection system comprising a high-pressure fuel injection pump, means for measuring the pressure delivered by the latter, an engine control unit, a starter, means for authorizing the first injection given by the fuel injection unit. engine control, characterized in that it comprises means for implementing a method according to the invention.
    [0003] Other characteristics will become apparent on reading the following description of examples of embodiments of a method according to the invention, accompanied by the appended drawings, examples given by way of nonlimiting illustration, in which: FIG. 1 represents a diagram of the fuel pressure during the start-up phase according to a first example of the method according to the invention for starting an internal combustion engine operating with a gasoline type fuel, at a temperature of -30 ° C .; FIG. 2 represents a diagram of the fuel pressure during the starting phase according to a second example of a method according to the invention for starting an internal combustion engine operating with a gasoline type fuel, at a temperature of 20 ° C. ° C; FIG. 3 represents a diagram of the fuel pressure during the starting phase according to a second example of a method according to the invention for starting an internal combustion engine operating with an ethanol fuel at a temperature of 20 °. VS ; FIG. 4 represents, by way of example, a diagram giving the pressure gradient defined with respect to an angular reference of the crankshaft, as a function of the starting temperature for a given configuration, for three examples of different fuels; FIG. 5 represents a diagram giving, for the three fuels of FIG. 4, the quantity of fuel to be injected during the first injection into each of the rolls in the starting phase as a function of the engine starting temperature; FIG. 6 represents a diagram giving the pressure gradient as a function of the quantity of fuel which must be injected by injection during the first injection into each of the rolls in the starting phase, corresponding to several given temperatures; FIG. 7 represents in the form of a table of correction coefficients resulting from FIG. 6, a fuel quantity correction coefficient to be applied for starting at a measured temperature, according to a point of measurement of the pressure gradient resulting from FIG. 1 schematically represents a method of starting a direct injection internal combustion engine of a vehicle, making it possible to accelerate the starting phase by adjusting the quantity of fuel injected. during this starting phase, before the established engine speed, by means of an injection system (not shown) comprising a high-pressure fuel injection pump, means for measuring the pressure delivered by the latter, for example a fuel pressure sensor 15 placed in a high pressure feed rail injectors fuel, an engine control unit ensuring the management of the injecti we. In FIG. 1, the abscissa represents the angular position of the crankshaft Ang CRK of the engine in degrees, and the ordinate axis the pressure P in Mpa of the fuel at the outlet of the high-pressure pump with fuel injection measured by 20 the fuel pressure sensor. The startup shown is a cold start. The fuel used is gasoline without a basic mixture, for example E0 fuel (0% ethanol), the engine temperature for the starting phase is -30 ° C, which is also the fuel temperature. The high pressure injection pump used (not shown) is a conventional pump in which the fuel intake is controlled by a valve controlled by the engine control unit, and which delivers the pressurized fuel into a storage rail (no represent). The maximum flow mode corresponds to the compression of the total volume of fuel admitted into the chamber or chambers of the pump, this maximum volume of fuel admitted and compressed being constant for the high compression dead points of successive compression of the pressure. The engine control unit decides how to operate at the maximum flow rate of the pump, by controlling the pump inlet valve, which triggers the measurement of the pressure. The engine control unit, or ECU, or engine ECU, controls the pump in maximum flow mode by closing the fuel inlet valve in the pump as soon as fuel compression begins, thus preventing any backflow to the fuel pump. covering part of the compressed fuel volume. According to the method, it is verified with the engine computer during the sampling of the pressure points that the mode of operation of the pump is a maximum flow operating mode. The method according to the invention is dependent on the decisions of the engine computer to operate or not in the maximum flow mode. Indeed, the ECU manages the servocontrol (PID) of the pressure in the accumulator rail. When the pressure in the accumulator rail is far below its set point, the PID regulator decides to operate at maximum speed to reach the setpoint as quickly as possible. During the start-up phase, in particular when cold, the pressure in the accumulator rail is far below its set point, requiring a mode of operation of the pump at maximum flow rate. The starter (not shown) is able to run the motor at a speed of about 200 rpm during the start-up phase. Curve 1 shows the evolution of the pressure during the start-up phase. This evolution shows an increase in pressure as soon as the pump is put into rotation. In Figure 1, the pump operates in maximum flow mode. The portions of pressure curve 1 with a high pressure gradient represent the compression of a volume of fuel admitted into the pump, which is maximum by the value reached of pressure variation as a function of the rotation of the crankshaft. The beginning of the flat parts corresponds to the top dead center of the pump, that is to say at the end of the compressions, themselves determining the beginning of the corresponding fuel intake phases in the pump. The flat portions of curve 1 represent the admission of the fuel into the pump. Curve 2 in FIG. 1 connects three high dead spots of the pump taken in its mode of operation at maximum flow. These top dead spots are located substantially at the top of the steep gradient slopes in Figure 1 which represent the successive compression of three identical fuel volumes each corresponding to the maximum fuel volume admitted and compressed in a pump chamber. The process shown in FIG. 1 comprises the following steps: - The high-pressure injection pump is rotated by means of a starter, the 0 ° position on the abscissa representing the position of the crankshaft at the moment when the starter is triggered, - The pressure of the fuel delivered by the high-pressure injection pump is measured by verifying by the information coming from the ECU that it operates in maximum flow mode, as indicated above, at least in two dead spots high compression (or TDC for "Top Dead Center" in English) 35 successive pump; this operation can be carried out as soon as possible after the crankshaft is turned into rotation by the starter, and preferably before the engine is synchronized. The pressure gradient of the fuel delivered by the high-pressure injection pump in the operating mode is determined. maximum flow, on the basis of the pressure measured at least at two high compression dead points (TDC), for example three TDC as shown in Figure 1, successive high pressure injection pump, preferably before the synchronization of the engine, - The established gradient is compared with at least one predetermined one-to-one table respectively matching a plurality of fuel quantities to be injected and a plurality of said pressure gradients, said at least one table being implemented in the engine control unit, preferably before the synchronization of the engine, - It is adapted by modifying if necessary the quantity of fuel injected during the start-up phase of the engine, for each injection made, according to the result of the comparison, in order to inject a quantity of fuel which corresponds, in the predetermined one-to-one table, to the established pressure gradient, from authorization of the first injection given by the engine control unit, which usually occurs after the synchronization of the engine has been performed, either from the first engine cycle following the synchronization. The synchronization is carried out according to any means well known to those skilled in the art, by means of the engine control unit and the signal sent to it by a crankshaft position sensor, and will therefore not be described in more detail. right here. According to the example shown in FIG. 1, the fuel pressure is measured at the first 3 top dead center of the pump at 270 ° from the rotational position of the crankshaft, in order to make sure that the pump is working well. at the maximum flow rate, then at the second 450 ° high compression point of the pump at the crankshaft rotation position, and preferably further at the third top compression point of the pump at 630. The position of rotation of the crankshaft, as shown in FIG. 1. These positions are advantageously determined by means of the crankshaft position sensor, and a law for connecting the angular positions between the crankshaft and the crankcase pump. high-pressure fuel injection, and the engine control unit (ECU) that applies this law. The law is given by the transmission ratio between the crankshaft rotation and the mechanically linked rotation of the injection pump, which establishes the position of the high compression dead points of the pump as a function of the angular positions of the crankshaft.
    [0004] The pressure gradient is thus preferably established with respect to a variation of the angular position of the high pressure injection pump, in the form dp / da with: - dp the pressure variation between the three high compression dead points or 5 successive TDCs of the pump, - the angular variation of the crankshaft between these three high compression dead spots or TDC successive pump. The use of the high dead points of compression makes it possible to use an angular reference system with which the starter speed of rotation which can vary with the temperature and the battery voltage is advantageously freed, and thus to offer a robustness of the pressure gradient in that it is always raised in the same configuration of the pump; accordingly, the correspondence table can more precisely match the quantities of fuel to be injected. In the example of FIG. 1, the following values were thus noted, as indicated in Table I below: Fuel Angular position Pressure Engine temperature Crankshaft petrol measured 1st point TDC 270 ° 6.198 MPa -30 ° C 2nd TDC point 450 ° 8.565 MPa -30 ° C Tc point TDC 630 ° 10.68 MPa -30 ° C A pressure gradient of 4.482 MPa for 360 ° angular displacement of the crankshaft. In the example shown in FIG. 1, the injection pressure is reached at point 6 at an angular position of the crankshaft of approximately 595 °, for a value of 10 MPa. Under these conditions, the choice of the number of reference points for the pressure should advantageously be two points 3 and 4 for calculating the pressure gradient. With this choice, an adjustment of the fuel quantity can be made before reaching the injection pressure, so before the first combustions.
    [0005] In FIG. 4, there is shown on the abscissa the starting temperature T start of the motor in degrees, and on the ordinate the pressure gradient dp / da as described above in bars by 360 ° of rotation of the crankshaft. The curves 7, 8, and 9 represent, for three fuels, for example respectively a fuel E0, a fuel E26, and a fuel E100, the evolution of this pressure gradient as a function of the starting temperature, in the rail high feed pressure of the fuel injectors when the high pressure pump is operating in maximum flow mode. Recall that the 3028891 9 E0 fuel is gasoline without ethanol, E26 is gasoline with an ethanol content of 26%, and E100 ethanol without gasoline. Thus, we will cover all possible fuel E0 fuel E100 fuel as detailed below. Remember that the fuel present in the tank may be a mixture of several different fuels, the ethanol content may be unknown at the time of startup and therefore between 0% and 100%. In known manner, the ECU knows the fuel present in the vehicle before stopping the engine, including strategies implemented in this ECU. From a pre-established diagram such as that of FIG. 4, which may comprise a larger number of curves representing a larger number of different fuels, at least one predetermined one-to-one table is made respectively matching a plurality of fuel to be injected and a plurality of pressure gradients. Preferably: The one-to-one array corresponding respectively a plurality of fuel quantities to be injected and a plurality of pressure gradients is predetermined for a given range of engine temperatures. A plurality of predetermined one-to-one arrays is implemented in the unit. motor, covering a plurality of motor temperature ranges, respectively, having at least one cold start temperature range; - the method further comprising measuring the engine temperature prior to comparing the gradient established with the or the predetermined one-to-one arrays. FIG. 4 shows by way of example a point 10 obtained by measuring a pressure gradient by a method as described above, for a starting temperature equal to 0 ° C. In FIG. 4 this measuring point of the pressure gradient dp / da is equal to 39 bars per 360 ° of rotation of the crankshaft (360 ° crk in FIG. 4). For example, suppose that the previous fuel known to the ECU is E26 fuel. The engine control unit thus expects a theoretical pressure gradient dp / da equal to 38.35 bar at 0 ° C for the fuel E26, as shown in FIG. 4, these data having been previously implemented in FIG. ECU. The one-to-one chart will allow the ECU to determine the amount of fuel MC to inject for a pressure gradient dp / da measured equal to 39 bar per 360 ° crankshaft rotation.
    [0006] The development of an example of a predetermined one-to-one array is detailed below with the aid of FIGS. 5 and 6. Such a predetermined one-to-one array is known to the ECU.
    [0007] In FIG. 5, the starting temperature T_start of the engine in degrees is represented on the abscissa, and the amount of fuel MC in mg, which is to be injected by injection from the first injection into each of the cylinders in the starting phase, is represented on the ordinate. that is to say, to the established engine speed. The curves 20, 21, and 22, 5 represent for the three different fuels of Figure 4, respectively a fuel E0, a fuel E26, and a fuel E100, the amount of fuel MC to be injected as a function of the engine temperature. With this FIG. 5, the quantity of fuel MC to be injected for any fuel between the fuel E0 and the fuel E100 is thus determined, as a function of the starting temperature T_start.
    [0008] According to FIG. 5, the ECU therefore prepares to conventionally inject a quantity of fuel equal to 70 mg of fuel during the first injection of each of the cylinders, according to the value of 70 mg read on the ordinate axis. for E26 fuel known to the ECU prior to engine shutdown. This amount of fuel does not correspond to that of the gradient measured for point 10 as shown, which should be higher. It should be noted that the point 10 has been shown in FIG. 5 only for information, not being known before the application of FIG. 6. In FIG. 6, the abscissa is represented by the quantity of fuel MC in mg which must be injected by injection during the first injection into each of the rolls in the starting phase, that is to say up to the engine speed, and in ordinates the pressure gradient dp / da in bars. 360 ° rotation of the crankshaft, applicable to the theoretical or measured pressure gradient. Fig. 6 illustrates a curve 23 having a plurality of segments 23a, 23b, 23c, 23d matching a plurality of fuel quantities MC and a plurality of pressure gradients dp / da for different engine temperatures as shown in Fig. 6, i.e., a segment of curve 23 corresponds to a given temperature or range of temperatures. From curve 23 a predetermined one-to-one array is made, respectively matching a plurality of fuel quantities to be injected and a plurality of said pressure gradients dp / da. Such a one-to-one array is directly implemented in the ECU since the latter can not directly exploit FIG. 6. In FIG. 6, the curve 23 is thus composed of several separate parts 23a, 23b, 23c, 23d assembled in FIG. each example linear and corresponding to a given temperature, the curve 23a corresponding to a motor temperature of 20 ° C, the curve 23b corresponding to a motor temperature of 10 ° C, the curve 23c corresponding to a motor temperature of 0 ° C , and the curve 23d corresponding to a motor temperature of -10 ° C. For carrying out an example of a one-to-one array, a plurality of preference values 3028891 11 are regularly distributed on the abscissa axis, and the corresponding plurality of values are selected on the ordinate axis, thus defining a predetermined one-to-one array. respectively matching a plurality of fuel quantities to be injected and a plurality of said pressure gradients, for a given range of engine temperatures, in the example of -10 ° C, 0 ° C, 10 ° C, 20 ° vs. The curve 23 covers all the fuels E0 to E100 because it comes from Figures 4 and 5 as follows: to obtain the segment 23a corresponding to a temperature of 20 ° C, a vertical is drawn in Figure 4 at the abscissa 20 ° C, and the values of dp / da are recorded on the y-axis for each of the 10 fuels E0, E26, and E100 shown. In FIG. 5, a vertical is also drawn at the abscissa 20 ° C. and the fuel quantity values MC are recorded on the ordinate axis for each of the same fuels E0, E26, and E100 shown. Then trace in Figure 6 the three points obtained for the temperature of 20 ° C illustrated by the segment 23a. The operation is similar for the selected temperatures of 10 ° C, 0 ° C, and -10 ° C to obtain segments 23b, 23c, and 23d respectively. It is possible to produce a one-to-one table by given temperature, or by given temperature range as explained above, for example four four-by-one tables per given temperature respectively corresponding to segments 23a, 23b, 23c, 23d. It is possible to alternatively perform a single one-to-one array from FIG. 6 including the four segments 23a, 23b, 23c, 23d. By definition, it can be decreed that a given segment in FIG. 6, for example the segment 23a, 23b, 23c, or 23d, is valid for a given range of temperatures extending around the single reference value, respectively around At 20 ° C, 10 ° C, 0 ° C, or -10 ° C. Note that at certain gradient values dp / da, for example 35 bar / 360 crk, two fuel quantity values are possible, but correspond to two different temperatures. It would thus be possible to interpolate several fuel quantity values MC for a given gradient, corresponding to several temperatures between two temperatures represented by segments in FIG. 6. In the one-to-one table, a single fuel quantity must correspond to a single fuel quantity. given gradient for a given temperature or range of temperatures. The choice of the ranges of each of the segments 23a, 23b, 23c, 23d forming the curve 23 of FIG. 6 has been determined in order to illustrate a reality of values actually encountered in the field for each of the temperatures represented. In FIG. 6, the measured point of pressure gradient dp / da has been set. As we know from FIG. 4, this point 10 is not on any fuel curve known by the ECU. Curve 23 allows the ECU to determine the correct amount of MC fuel to be injected for the measured value of the dp / dα gradient. According to this measured point, for a pressure gradient of 39 bars per rotation of the crankshaft 360 °, at 0 ° C., the quantity of fuel to be injected at the first injection of each of the cylinders should be 77, 2 mg. Whereas for the E26 fuel known before stopping the engine, the theoretical dp / da pressure gradient is equal to 38.35 bar at 0 ° C. (see FIG. 4) and corresponds to a fuel quantity MC equal to 70 mg. Therefore, the correct amount of fuel MC that should be injected has a theoretical increase of 11.03% over the amount of 70 mg initially provided by the ECU 10 for the fuel E26. Since the ECU can not directly exploit the curves of Figure 6, it should preferably carry out a numerical extrapolation in order to determine the correct quantity of fuel to be injected, from the one-to-one table, for example as explained below with the using Figure 7.
    [0009] FIG. 7 represents an example of a table of factors for correcting the quantity of fuel to be injected, as a function of the gradient dp / da measured and with respect to the theoretical dp / da gradient as defined above. The table of FIG. 7 corresponds to a digital exploitation of FIG. 6 by the ECU, for a range of gradients dp / da of between 35 and 40 bar / 360 ° crk given by way of example, which is relevant with respect to FIGS. expected measurements of pressure gradients dp / da and determined according to the method according to the invention. The values of dp / da limits in the table of FIG. 7 are functions of what are given as temperature and sizing limits of the high-pressure injection pump and the high-pressure rail (rail volume and engine displacement). pump). The gradient dp / da measured according to the method according to the invention is read on the vertical axis of the table, and the reference theoretical dp / da gradient is read on the horizontal axis of the table, which gives the point 10 in the example described, which has been positioned on the table of FIG. 7. The point 10 corresponds to a value between two columns of the array, but corresponds to a value that is just one line of the array: a simple interpolation must therefore be performed by the ECU to obtain the correcting coefficient to be applied in the example. According to the example of the point 10 measured, the correction to be made by the ECU to the fuel quantity provided for the injection as explained above, that is to say 70 mg, is thus of the order of 11 % (theoretical of 11.03%), to obtain an amount of 77.2 mg corresponding to the measured gradient of 39 bar / 360 ° crk. According to the table of FIG. 7, a linear interpolation from the data gives a correction factor to be applied to the fuel quantity equal to 1.100 with respect to the amount of fuel established on the basis of the theoretical pressure gradient of 38, 35 bar by 360 ° of 3028891 13 rotation of the crankshaft for fuel E26. This correction is calculated once before the first injection and then applied throughout the start up to idle speed established. For the example of FIG. 2, the same reference numerals as those used for FIG. 1 have been used for the same elements. The example of FIG. 2 was carried out under conditions identical to those of the example of FIG. 1, with the exception of the engine temperature, which is now 20 ° C. This temperature represents a cold start according to a much higher ambient temperature than that of the example of FIG.
    [0010] In the example of FIG. 2, the following values were recorded, as indicated in Table II below: Fuel Angular position Pressure Engine temperature Crankshaft petrol measured 1st point TDC 270 ° 4,128 MPa 20 ° C 2nd point TDC 450 ° 5,736 MPa 20 ° C 3rd point TDC 630 ° 7,233 MPa 20 ° C That is a pressure gradient of 3,105 MPa for an angular displacement of the crankshaft of 360 °. That is, a gradient 30% less than that of the example of FIG. 1. In the example shown in FIG. 2, the injection pressure is reached at point 6 at an angular position of the crankshaft of about 1093.degree. for a value of 10 MPa. As shown in the figure, three points 3, 4, and 5 can be used to calculate the pressure gradient, and to obtain an adjustment of the amount of fuel to be injected before reaching the injection pressure, thus before the first combustions. For the example of FIG. 3, the same reference numerals as those used for FIG. 1 have been used for the same elements. In the example of FIG. 3, the following values were recorded, as indicated in Table III below: Ethanol fuel Angular position Pressure Engine temperature of the crankshaft measured 1st point TDC 270 ° 46.9 bars 20 ° C 2nd TDC point 450 ° 65.15 bar 20 ° C 3rd point TDC 630 ° 82.01 bar 20 ° C 3028891 14 Either a pressure gradient of 3.511 MPa for an angular displacement of the crankshaft of 360 °. That is, a gradient 13% greater than that of the example of FIG. 2. In the example shown in FIG. 3, the injection pressure is reached at point 6 at an angular position of the crankshaft of about 924.degree. for a value of 10 MPa. As shown in the figure, it is possible to use three points 3, 4, and 5 for calculating the pressure gradient, and to obtain an adjustment of the quantity of fuel to be injected before reaching the injection pressure, so before first combustions. From these three examples above, it is noted that the differences between the pressure gradients are sufficiently large to distinguish the adjustments to be made to the fuel mass to be injected. An example of a starting device for a direct injection internal combustion engine for accelerating the start-up phase by adapting the quantity of fuel injected during this start-up phase before the engine is set up by an injection system comprising in a known manner a fuel injection high pressure pump, means for measuring the pressure delivered by the latter for example by means of a fuel pressure sensor FUP placed in a pressurized fuel accumulator rail, an engine control unit or ECU, a starter, authorization means of the first injection given by the engine control unit, further comprises according to the invention in the form of software implemented in the engine control unit, means to carry out a method as described in one or more examples above, which may advantageously be appropriate depending on the use and u geographical location in which the vehicle is used, for example depending on the temperatures of the place and the fuels used and / or a mixture thereof.
    权利要求:
    Claims (6)
    [0001]
    REVENDICATIONS1. A method of starting a direct injection internal combustion engine of a vehicle, to accelerate the starting phase by adjusting the amount of fuel injected during this start-up phase, before the established engine speed, by means of a injection system comprising a high-pressure fuel injection pump, means for measuring the pressure delivered by the latter, an engine control unit, characterized in that said method comprises the following steps: - Turning the injection pump high pressure by means of a starter, - Measure the pressure of the fuel delivered by the high-pressure injection pump, taken at least two successive high compression dead points of the pump operating in maximum flow mode, - Establish the gradient of pressure, on an angular reference, the fuel delivered by said high pressure injection pump, on the basis of the pressure measured at said at least two successive high compression dead points of the high-pressure injection pump characterized by their angular positions, - comparing said established gradient with at least one predetermined one-to-one table respectively matching a plurality of quantities of fuel to be injected and a plurality of said pressure gradients, said at least one table being implemented in the engine control unit, - Adapting the quantity of fuel injected during the engine start-up phase, according to the result of the comparison, in order to inject a quantity of fuel corresponding, in the predetermined one-to-one table, to the established pressure gradient, upon authorization of the first injection given by the engine control unit.
    [0002]
    The method of claim 1, wherein: said at least one one-to-one array respectively matching a plurality of fuel quantities to be injected and a plurality of pressure gradients is predetermined for a given range of engine temperatures, - a plurality said predetermined one-to-one arrays are implemented in the engine control unit, covering a plurality of engine temperature ranges, respectively, having at least one cold start temperature range, said method further comprising measuring the engine temperature before comparing said established gradient with said at least one predetermined one-to-one array.
    [0003]
    3. A method according to any one of claims 1 or 2, wherein the position of said at least two successive high compression dead points of the fuel injection pump is determined by means of a crankshaft position sensor of the motor, a law of connection of the angular positions between the crankshaft and the high-pressure fuel injection pump, and the engine control unit.
    [0004]
    4. A method according to any one of claims 1 to 3, wherein the pressure gradient is set with respect to a variation of the angular position of the high pressure injection pump, in the form dp / da with: - dp the variation of pressure between said at least two successive high compression dead points of the pump, - the angular variation of the crankshaft between said at least two successive high compression points of the pump.
    [0005]
    The method according to any one of claims 1 to 4, wherein the pressure gradient of the fuel delivered by said high pressure injection pump is set with three or more high compression deadheads of the high pressure injection pump. 20
    [0006]
    6. Starting device for a direct injection internal combustion engine for accelerating the start-up phase by adapting the quantity of fuel injected during this start-up phase before the engine is set up by an injection system comprising a fuel injection pump. high pressure injection of the fuel, means for measuring the pressure delivered by the latter, an engine control unit, a starter, means for authorizing the first injection given by the engine control unit, characterized in that it comprises means for implementing a method according to any one of claims 1 to 5.
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    同族专利:
    公开号 | 公开日
    CN107110038A|2017-08-29|
    FR3028890B1|2019-08-23|
    FR3028890A1|2016-05-27|
    US20170350341A1|2017-12-07|
    CN107110038B|2020-07-03|
    BR112017010464A2|2018-04-03|
    US10253719B2|2019-04-09|
    FR3028891B1|2019-08-16|
    WO2016078754A1|2016-05-26|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP1975398A2|2007-03-26|2008-10-01|Hitachi, Ltd.|Control device for high-pressure fuel system|
    US20100268441A1|2009-04-15|2010-10-21|Denso Corporation|Controller for fuel pump|
    DE102010027675A1|2010-07-20|2012-01-26|Continental Automotive Gmbh|Method for detecting faulty components of fuel injection system of internal combustion engine, involves performing routine test, by which increase and subsequent lowering of pressure of fuel is carried out in fuel injection system|
    DE102011077404A1|2011-06-10|2012-12-13|Continental Automotive Gmbh|Method for determination of fuel quality in high pressure injection apparatus in motor car, involves comparing measurement curve with comparison curves, and determining fuel quality when measurement curve corresponds to comparison curves|
    JP3653919B2|1997-03-04|2005-06-02|日産自動車株式会社|In-cylinder direct injection type spark ignition internal combustion engine fuel injection control device|
    DE10211283A1|2002-03-14|2003-09-25|Bosch Gmbh Robert|Operating method for automobile engine fuel metering system with limitation of variation rate of pressure in high pressure region of latter|
    DE102007005685B4|2007-02-05|2009-04-23|Continental Automotive Gmbh|Method for determining a control variable for a pressure control of a high pressure accumulator in an injection system|
    JP5217514B2|2008-03-04|2013-06-19|日産自動車株式会社|Engine fuel supply system|
    US7832375B2|2008-11-06|2010-11-16|Ford Global Technologies, Llc|Addressing fuel pressure uncertainty during startup of a direct injection engine|
    JP2010255478A|2009-04-23|2010-11-11|Denso Corp|Fuel injection quantity control device for engine|
    JP5191983B2|2009-12-16|2013-05-08|日立オートモティブシステムズ株式会社|Diagnostic device for internal combustion engine|
    KR20120059984A|2010-12-01|2012-06-11|현대자동차주식회사|Fuel Injection Control Method for GDI Engine|
    CN104919163B|2013-01-08|2017-08-25|沃尔沃卡车集团|For determining the method and apparatus of fuel mass and possessing the vehicle of the device|FR3043141B1|2015-10-29|2017-11-03|Continental Automotive France|METHOD FOR VERIFYING THE FUNCTIONALITY OF A HIGH PRESSURE FUEL SUPPLY SYSTEM OF AN INTERNAL COMBUSTION ENGINE|
    DE102016225435B3|2016-12-19|2018-02-15|Continental Automotive Gmbh|Method for operating an internal combustion engine with fuel detection|
    US10344703B2|2017-06-29|2019-07-09|GM Global Technology Operations LLC|Injector delivery measurement with leakage correction|
    法律状态:
    2016-05-27| PLSC| Publication of the preliminary search report|Effective date: 20160527 |
    2016-11-18| PLFP| Fee payment|Year of fee payment: 2 |
    2017-11-21| PLFP| Fee payment|Year of fee payment: 3 |
    2018-11-23| PLFP| Fee payment|Year of fee payment: 4 |
    2019-11-20| PLFP| Fee payment|Year of fee payment: 5 |
    2020-11-20| PLFP| Fee payment|Year of fee payment: 6 |
    2021-08-20| TP| Transmission of property|Owner name: VITESCO TECHNOLOGIES, DE Effective date: 20210712 |
    2021-11-22| PLFP| Fee payment|Year of fee payment: 7 |
    2022-02-11| CA| Change of address|Effective date: 20220103 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1461294|2014-11-21|
    FR1461294A|FR3028890B1|2014-11-21|2014-11-21|METHOD FOR STARTING A DIRECT INJECTION INTERNAL COMBUSTION ENGINE BY ADAPTING THE INJECTED FUEL QUANTITY|CN201580074091.6A| CN107110038B|2014-11-21|2015-11-16|Method for starting a direct injection internal combustion engine by adjusting the quantity of fuel injected|
    PCT/EP2015/002285| WO2016078754A1|2014-11-21|2015-11-16|Method for starting a direct-injection internal combustion engine by adapting the quantity of fuel injected|
    BR112017010464A| BR112017010464A2|2014-11-21|2015-11-16|method for starting a direct injection internal combustion engine by adapting the quantity of fuel injected|
    US15/527,828| US10253719B2|2014-11-21|2015-11-16|Method for starting a direct-injection internal combustion engine by adapting the quantity of fuel injected|
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