DE10301956B4 - Collecting fuel injection system - Google Patents

Abstract

Collective fuel injection device with:
a high pressure pump (7) for drawing fuel from a fuel tank (6);
a common rail (5) for collecting high-pressure fuel discharged by the high-pressure pump;
a plurality of fuel injection valves (1 to 4), which are respectively mounted on a respective cylinder of an internal combustion engine and inject the high-pressure fuel collected in the common rail into a combustion chamber of the cylinder;
a drive condition detection unit (70) for detecting a drive state of the internal combustion engine;
a fuel pressure detection unit (81) for detecting a fuel pressure of the high pressure fuel collected in the common rail; and
an exhaust control unit (10, S605, S607) for controlling an exhaust of the high-pressure pump in response to the driving state detected by the driving state detection unit and the fuel pressure detected by the fuel pressure sensing unit,
characterized in that
When the internal combustion engine is started, the discharge control unit (10, S605, S607) detects a time (Ts) elapsed before the engine speed (N) reaches a predetermined speed (Ns), and a pressure increase characteristic (ΔPc / ΔT) the fuel pressure ...

Description

The The present invention relates to a collection fuel injector and in particular to improving the stability of a Internal combustion engine with a common rail fuel injection device, the high pressure fuel discharged from a high pressure pump in a common rail collects and collects the high-pressure fuel through a Fuel injector injects to the internal combustion engine.

When a common rail fuel injection device for a fuel injection system A diesel engine is a collective fuel injection device known. This device has a high pressure pump that through the Torque of the crankshaft of the diesel engine is driven to from a fuel tank sucked fuel with pressure and eject, and a common rail acting as a surge tank of high pressure fuel serves, which is ejected from this high-pressure pump.

at This collecting fuel injection device is connected to the high-pressure pump attached adjustment valve based on a control signal of an electronic control unit (ECU) controlled by the High pressure pump to a fuel pipe to the common rail guided high pressure fuel adjust. Then the common rail pressure in this way and Way to a desired one Injection pressure controlled.

at the conventional one Device becomes a change when ejecting from the high pressure pump due to design or operation changes of the set solenoid valves caused even if the Einstellsolenoidventile the same shape exhibit. In particular, when the engine is started, effect The changes from the adjusting solenoid valves, namely changes from the high pressure pumps, changes the injection quantity or the injection pressure of the fuel that injected from a fuel injection valve into the diesel engine becomes. As a result, this poses a problem due to a change of starting assets the engine.

Furthermore, the shows DE 100 44 514 A1 a fuel injection device with a common rail, an injection valve, a high-pressure fuel pump with a Saugmessventil, a pressure sensor and a control device. In the fuel injection apparatus, the deviation of the actual suction volume from the specific suction volume is reduced by correcting variations in the measuring characteristics of the suction measuring valve. The controller controls the fuel pressure in an accumulator chamber of the high-pressure fuel pump by controlling the amount of the fuel sucked into the pressure chamber by driving the suction measuring valve based on the detected fuel pressure. A suction start current calculating means calculates the suction start current value at which the suction measuring valve actually starts the suction based on the change of the fuel pressure within the pressure storage chamber when the drive current is gradually changed from this state.

Furthermore, the document relates DE 198 53 823 A1 a method for operating an internal combustion engine having a fuel pump, a pressure accumulator and a control unit. The delivery rate of the fuel pump is controllable via a characteristic field as a function of a plurality of input variables. The input variables relate, for example, the amount of fuel to be injected and the speed of the internal combustion engine. The map, for example, adjusted at each startup, taking into account a measured pressure in the pressure accumulator and its deviation from the setpoint.

In addition, the document describes DE 689 22 380 T2 a fuel injection control apparatus for a common rail internal combustion engine, which is pressurized with a fuel pump. The fuel pressure in the common rail is controlled via a pressure control valve at a starting operation of the internal combustion engine, so that the fuel pressure is not increased further, if it is equal to or greater than a target fuel pressure.

Furthermore, the document shows JP 09-088670 A (Abstract) A fuel injection control device for an internal combustion engine, in which the rotational speed is detected after an engine start. When the rotational speed does not reach a certain rotational speed before a certain time has elapsed, a correction coefficient which corrects the fuel injection amount at the time of starting the engine is increased.

The publication JP 04-339152 A (Abstract) relates to a fuel injection control apparatus of an internal combustion engine in which, at the time of starting the engine, a control valve is controlled so that a fuel pressure in a common rail assumes a low target fuel pressure.

It the object of the present invention is to provide a collecting fuel injection device, the one desired startability ensure an internal combustion engine can, without increasing emissions of harmful exhaust gases irrespective of changes made by High pressure pumps.

According to the present The invention has a collection fuel injector a high pressure pump, a common rail, fuel injection valves and an exhaust control unit. When an engine is started, the exhaust control unit detects the time that elapsed before the speed of the engine reaches a predetermined speed, and detects a pressure increasing characteristic the fuel pressure. When the elapsed time is a predetermined one Start time exceeds, then increased or decreases the exhaust control unit the output at the next Engine starting operation according to the pressure increasing characteristic.

If alternatively a predetermined time after the start of the engine has elapsed, then the exhaust control unit determines if the rotational speed the engine reaches a predetermined speed. The exhaust control unit corrects the output at the next Engine starting process in response to the actual Fuel pressure when the predetermined time has elapsed and an actual Speed of the engine is compared with a predetermined Speed of the engine.

The above mentioned object as well as further features and advantages The present invention will become more apparent from the following detailed Description with reference to the accompanying drawings.

1 shows a schematic view of a common rail fuel injection device of the first embodiment according to the present invention;

2 shows a schematic view of one in the 1 shown control system;

3 shows a schematic view of a quantity control valve in the 1 shown high-pressure pump, 3 (a) shows a cross-sectional view of the quantity control valve, and the 3 (b) shows an enlarged view of an inlet port, when this from a direction B in the 3 (a) is looked at;

4 shows a graphical representation of the drive characteristics of the in 3 shown length valve;

5 shows a flowchart of a pre-processing of a start operation of a high-pressure pump control, which by a in the 1 shown ECU is performed;

6 FIG. 12 is a flow chart showing a start operation of a high-pressure pump controller according to the first embodiment of the present invention; FIG.

7 FIG. 12 is a flow chart showing a start operation of a high-pressure pump controller according to the second embodiment of the present invention; FIG. and

8th FIG. 12 is a flow chart showing the control of a high-pressure pump according to the third embodiment of the present invention. FIG.

preferred embodiments The present invention will be described with reference to various embodiments described in which a collecting fuel injection device as a Common rail Krafstoffeinspritzvorrichtung a diesel engine is used.

(First embodiment)

Like this in the 1 is shown, a common rail fuel injection device has a high pressure pump 7 for sucking fuel from a fuel tank 6 , a common rail 5 , which is designed in the construction of an intermediate container for collecting high pressure fuel from the high pressure pump 7 is ejected, a variety of fuel injection valves (injectors) 1 to 4 , each on a respective cylinder of a multi-cylinder (4 cylinder according to the 1 ) Diesel engine (engine) are attached to high pressure fuel, which in the common rail 5 is collected, into the combustion chamber of the cylinder and inject, a fuel pressure detection unit 81 for detecting the fuel pressure of the in the common rail 5 collected high-pressure fuel and an exhaust control unit 10 for controlling the ejecting operation of the high-pressure pump 7 in response to a drive condition detection sensor group 70 detected driving state and one by a fuel pressure detection unit 81 recorded fuel pressure. Here is this control unit 10 an electronic control unit (ECU) for electronically controlling not only the high-pressure pump 7 , but also the variety of injectors 1 to 4 ,

Here, the engine is started by rotating the flywheel (not shown) of the engine at a speed greater than a minimum speed required for starting the engine by a starting device (not shown) that is powered by the electric power a battery is turned. The power supply to the starting device is provided by the ECU 10 is started when a vehicle occupant switches an ignition switch from an OFF position to a start position (ST position), namely, when a starter ON signal is turned ON.

Each injector of the plurality (in the present embodiment 4) injectors 1 to 4 is attached to the combustion chamber of the respective cylinder of the engine and injects the high-pressure fuel into the respective combustion chamber of the engine. Then those in the engine from the respective injectors 1 to 4 Injected fuel amount and fuel injection timing determined by supplying power to the respective injection period control solenoid valves (injection period change units) 11 to 14 as actuators is electronically controlled and the power supplied by the ECU 10 is stopped.

The common rail 5 is designed as an intermediate tank for collecting high pressure fuel under a comparatively high pressure (100 to 1000 times the atmospheric pressure than a common rail pressure), and is compatible with the various injectors 1 to 4 via a high pressure pipe 8th connected. Here are the different injectors 1 to 4 , the common rail 5 and a fuel return pipe 9 from the high pressure pump 7 to the fuel tank 6 designed so that they also receive pressure from a pressure limiting device 15 relax so that the common rail pressure in the common rail 5 does not exceed a collective pressure limit.

The high pressure pump 7 has a feed pump in which a feed pump (not shown) is installed, which rotates in accordance with the rotation of the crankshaft (not shown) of the engine to the fuel in the fuel tank 6 through a fuel pipe 17 with a fuel filter disposed therein 16 suck, and applied to the fuel sucked by the feed pump with pressure and forwards the high-pressure fuel. This high pressure pump 7 is with a Mengensteuersolenoidventil 19 equipped as a discharge adjusting solenoid valve.

This quantity control solenoid valve (injection pressure control solenoid valve) 19 is an injection pressure changing unit that is controlled by a control signal from the ECU 10 electronically controlled to the common rail 5 through the fuel pipe 18 from the high pressure pump 7 adjusted high pressure fuel amount, thereby an injection pressure for injecting the fuel into the combustion chambers of the engine from the respective injectors 1 to 4 to change.

The ECU 10 consists of a CPU for performing control processing and calculation processing, a ROM for storing various kinds of control programs and data, a RAM for storing input data, an input circuit, a output circuit, a power supply circuit, and an injector drive circuit (EDU). 20 , This ECU 10 controls the injection pressure control solenoid valve 19 the high pressure pump 7 and the injection period control solenoid valves 11 to 14 injectors 1 to 4 according to the driving state or the like of the engine, by the driving condition detecting sensor group 70 is detected.

The EDU 20 receives a control signal (for example, a control pulse signal) received from the ECU 10 is discharged to increase the voltage of a battery (not shown) so that a valve opens or closes in response to a fuel injection timing (valve opening timing) and the fuel amount (injection period) by the ECU 10 is calculated so as to supply power or stop the power supply through the various injection period control solenoid valves 11 to 14 the various injectors 1 to 4 to control.

The drive condition detection sensor group 70 for inputting signals representing the driving state of the engine include a rotational speed sensor 71 for detecting the rotational speed of the engine, an accelerator position sensor 72 for detecting the depression amount of an accelerator pedal (accelerator position) and an intake air temperature sensor 73 for detecting the temperature of intake air sucked by the engine, a cooling water temperature sensor 75 for detecting the cooling water temperature of the engine and a crank angle sensor 77 for detecting the rotational angle of the crankshaft of the engine and the rotational speed of the engine.

Furthermore, ECU 10 with the fuel pressure sensor 81 for detecting the fuel pressure (injection pressure, common rail pressure) in the common rail 5 collected high-pressure fuel and a fuel temperature sensor (fuel temperature detection unit) 82 for detecting the temperature of the fuel in the return pipe 9 connected.

The ECU calculates here 10 in the stationary driving state of the engine, the fuel injection timing (valve opening timing) of the injectors 1 to 4 and the output from the high pressure pump 7 (Fuel delivery period) based on signals from the crank angle sensor 77 , such as a crank angle speed pulse and a camshaft speed pulse, and controls a timing for supplying a current through the injection pressure control solenoid valve 19 the high pressure pump 7 so as to increase the common rail pressure to keep to the most appropriate injection pressure (target pressure).

Then the ECU calculates 10 the amount of fuel injection from values determined by the speed sensor 71 , the accelerator position sensor 72 , the cooling water temperature sensor 75 or the fuel temperature sensor 82 be measured. To then achieve the calculated fuel injection amount, the ECU drives 10 the injection period control solenoid valves 11 to 14 the various injectors 1 to 4 by an injector energization time command (value) derived from the fuel pressure in the common rail 5 is calculated for the respective drive state, thereby driving the engine.

The ECU 10 is further configured so that when the driver starts a power supply to the starting device for the purpose of starting the engine to crank the crankshaft of the engine at a speed that is greater than a required minimum speed, the ECU 10 calculates an injection start pressure (a target common rail pressure in the period of startup = a target pressure) that is most suitable for starting the engine, for example, according to a by the cooling water temperature sensor 25 detected engine cooling water temperature (TW) or a correction amount, which is obtained by adding a starter ON duration to the engine cooling water temperature (TW) (injection start pressure determination unit), and it inhibits the injector energization time command (injector opening command) to the various injectors 1 to 4 until the common rail pressure (actual common rail pressure) passing through the fuel pressure sensor 81 is detected, has increased above the target pressure. In this case, it is not necessary, depending on a target start time to ensure the desired starting power of the engine, the ECU 10 to build up so that the ECU 10 prevents the aforementioned injector opening command.

In this regard, the ECU 10 in the present embodiment, the ECU 10 prevents the injector opening command until the actual common rail pressure has increased beyond a predetermined pressure. This can shorten a time from the start of the injection operation of the fuel to the realization of an effective combustion (complete combustion).

Here, if the common rail fuel injection apparatus having the structure described above maintains the predetermined pressure after the common rail pressure has become the target pressure, then a change in the starting time is not caused by changes in the common rail fuel injection apparatuses even if the operating characteristics of the fuel injectors differ slightly from device to device. However, the target pressure at startup is set to the pressure smaller than a common rail pressure during a stationary drive mode, and during the startup operation, there is a transient state where the common rail pressure reaches the target pressure and then further increases , For this reason, there is the possibility that the transient characteristic of the common rail pressure during the starting operation is affected by a change among the common rail fuel injection devices, particularly a change among the high pressure pumps 7 for guiding the high-pressure fuel such that changes in the starting time between the actual internal combustion engines are caused by the common-rail fuel injection apparatuses with respect to the target start-up of the engine, and thus the target start time becomes unsatisfactory.

on the other hand there is also a method for inhibiting the injector opening command, until the common rail pressure from the target start pressure to the common rail pressure during the stationary Drive mode increased Has. However, extended this procedure will take the unused time of the boot process before the complete Combustion of the fuel has occurred in the engine. This procedure is extended the starting time for cranking the engine, and that time, the from the time elapses when the driver the Power supply to the starting device starts to burn to complete, whereby it is difficult to ensure a desired starting ability. In some cases it is possible, that this method increases the battery current consumption, so that the battery discharges and it becomes difficult to start the engine.

Thus, in the present embodiment, there is provided a collection type fuel injection device having the following features, and thus a desired starting capability of the internal combustion engine regardless of changes of the high-pressure pumps 7 can guarantee.

A change in the transition characteristic of the common rail pressure Pc caused by changes in the high-pressure pumps 7 (please refer 6 (b) ) is caused, namely a change in the output of the high-pressure pump 7 can be eliminated by starting a high pressure pump control start processing S600 (FIG. 5 . 6 ) added is to perform a discharge correction.

In this high pressure pump start control processing S600, a correction of an amount of driving for driving the quantity control valve becomes 19 as the discharge adjustment solenoid valve of the high pressure pump 7 through the ECU 10 carried out. In this regard, the change causes among the quantity control valves 19 In addition, a change of the discharge with respect to the same amount of drive, so that the above-mentioned correction of the discharge of the high-pressure pump 7 can be performed in an unsuitable manner at the initial start, but that this causes an ejection, which is suitable in the next startup process. In this way, the high-pressure pump start control processing S600 is continuously performed every start-up to optimize the discharge, thereby ensuring the predetermined start-up capability.

The high pressure pump start control processing S600 of one embodiment will be described with reference to FIGS 5 and 6 described below. The 5 FIG. 12 shows a flowchart of pre-processing of the high pressure pump start control processing S600 executed by the ECU 10 according to the 1 is performed. The 6 Fig. 10 shows a flowchart of the high pressure pump start control processing.

When the engine is to be started, the vehicle occupant first turns the ignition switch from the OFF position to the ON position to rotate the starter motor by means of an electric current from the battery and at the same time drives a pinion gear driven by an over-rotation clutch with a ring gear engage the outer periphery of the flywheel, which is directly connected to the crankshaft of the engine to rotate the flywheel. In this way, the crankshaft is rotated to vertically move a piston in the cylinder of the engine so as to suck air into the cylinder through an intake pipe. On the other hand, the high-pressure pump acts 7 that of the fuel tank 6 fuel sucked by the rotation of the crankshaft of the engine also with pressure to the fuel pressure Pc in the common rail 5 to increase.

Like this in the 5 is determined at a step S501, it is determined whether the ignition switch has been switched to the ST position, and the starter on signal generated by the contact of a movable contact with a stationary contact of the starting device is then in the on state. This serves to detect a start of the power supply to the starting device. If the starter ON signal is in the OFF state, then the processing is ended. In contrast, if the starter signal is in the ON state, the processing proceeds to the high pressure pump start control processing in step S600.

In this regard, in the state of a startup drive state in which the starter ON signal is determined to be ON, the engine is cranked at the speed greater than a minimum speed (for example, 400 RPM) required to start the engine Engine is required, so the high-pressure pump 7 is driven by the rotation of the crankshaft, and a current passes through the injection pressure control solenoid valve 19 to the fuel pressure in the common rail 5 (= Fuel pressure in the rail) Pc gradually increase.

Next, in the high pressure pump start control processing S600, control processing of S601 to S607 is performed to set the predetermined drive amount of the injection pressure control solenoid valve 19 in the next starting operation, if a time elapsed until reaching a predetermined number of revolutions of the engine (idling speed in the present embodiment) exceeds the target starting time.

Like this in the 6 is shown, at S601, the driving amount D of the injection pressure control solenoid valve 19 the high pressure pump 7 set to a predetermined value D1. Here, in the initial starting operation, this value D1 is an initial set value, namely, a predetermined value set at the time of delivery from a manufacture, and in the subsequent starting operation, the initially set value (which is not subject to correction) or one by means of a Correction Refreshed value depending on the history of the correction used as the value D1. The injection pressure control solenoid valve 19 is calculated on the basis of this predetermined value D1 by the ECU 10 driven and controlled to the output of the high pressure pump 7 set high pressure fuel out. Then the fuel pressure in the common rail 5 Gradually increased in response to this output.

Around To simplify the description, it is assumed that the initial one fixed value as the predetermined value D1 with respect to the drive amount D is input, and the control processing becomes S602 described.

At S602, a time Ts elapsed before the rotational speed of the engine N reaches a predetermined rotational speed (idling speed in the present embodiment) Ns is detected by the rotational speed sensor 71 as the driving condition detection sensor group 70 detected ( 6 (a) ), and the pressure increasing characteristic of the common rail pressure Pc in the common rail 5 becomes through the fuel pressure sensor 81 as a pressure detection unit detects, and thus a fuel pressure increase per unit time (.DELTA.Pc / .DELTA.T) by the ECU 10 calculated. In this regard, (a) at step S602 hereshows a schematic representation of the so-called engine speed characteristic with rapid increase in the starting process, and provides a plot of the time Ts from the starting operation of the starting device (for example, a time when the starter signal is turned ON) State) about the state of a rapid increase in the engine speed up to the time when the rotational speed of the engine N returns to the idling speed Ns. (b) at S602 is a schematic representation of a pressure increasing characteristic of the common rail pressure Pc at the starting operation, and the characteristic shown by a broken line and the two-dot chain line represents the case where (ΔPc / ΔT) is large, and the case where (ΔPc / ΔT) is small with respect to the pressure increasing characteristic shown by a solid line. Here are factors of changes caused by the changes among the injection pressure control solenoid valves 19 for adjusting the output of the common rail 5 led high-pressure fuel, with reference to the 3 and the 4 described below. The 3 shows a schematic representation of the quantity control valve in the 1 shown high pressure pump 7 , The 3 (a) shows a cross-sectional view of the quantity control valve and the 3 (b) shows an enlarged view of an inlet port, if this in a direction B in the 3 (a) is looked at. The 4 shows a graphical representation of a drive characteristic of the in 3 shown quantity control valve.

Like this in the 3 (a) is shown, the injection pressure control solenoid valve 19 in the present embodiment, a well-known quantity control valve, and it has a solenoid drive portion with a movable core 19a , a stator core 19b that together with the movable core 19a forms a magnetic circuit, and an electromagnetic coil 19c which then generates an electromagnetic force when supplied with a current, a valve body 19d , a valve element 19e that enters the valve body 19d is slidably received and located together with the movable core 19a can reciprocate, and a valve portion with a biasing spring 19f for biasing the valve element 19e to the side of the movable core 19a , Hereby, this solenoid valve changes 19 the opening area A of the inlet port (see 3 (b) by means of an ON-OFF control (ON-OFF solenoid valve), or it may be a linear solenoid valve in which the opening area A of the inlet port is defined by a position in the axial direction of the valve element 19e is changed, which is in the axial direction in the valve body 19d emotional. In the ON-OFF solenoid valve, this opening area content A may be changed by means of a pulse duration control in which a valve opening / closing period is changed by the ECU. On the other hand, even in the linear solenoid valve, the opening area A can be changed by changing an average drive current by the pulse duration control (FIG. 4 ).

In this regard, it is assumed that the injection pressure control solenoid valve 19 is a solenoid valve, and the following description will be made accordingly.

Similar to the drive characteristics of the in the 4 shown injection pressure control solenoid valve 19 in which a horizontal axis represents a driving amount D and a vertical axis represents the opening area A of the intake port, namely, the injection pressure control solenoid valve 19 , the opening area A content decreases, that is, the discharge of the high-pressure pump 7 decreases as the drive amount increases. On the other hand, the opening area A of the injection pressure control solenoid valve increases 19 , namely the output of the high-pressure pump 7 increases as the drive amount decreases.

Factors that change the output of the high-pressure pump 7 with respect to the injection pressure control solenoid valve 19 In the electromagnetic drive section, the effect of an attraction force Fc caused by the change of the solenoid coils 19c which generates the electromagnetic force, and in the valve portion, the action of a spring constant K of the biasing spring for determining the position of the valve element in the axial direction by the balance between the biasing force and the attraction force in response to the solenoid coil 19 generated electromagnetic force, the effect of their set load Es and an effect that is caused in the production within a design tolerance, such as the effect of the valve opening position of the valve element together with the movable core, which is driven by the attraction force. For this reason, the output of the high-pressure pump 7 by changes in the single-point pressure control solenoid valves 19 changed, even if by the ECU 10 delivered amount of drive remains the same.

In contrast, in the embodiment of the present invention, in the case where the predetermined starting power can not be ensured, or in other words, in the case where the time Ts until the start passage passes the set time Ta, the following correction is made.

at S603, it is determined whether the time Ts measured at S602 is smaller as the target time Ta (for example, 20 seconds). If the time Ts is smaller than the target time Ta, then the control processing is ended. In contrast, if the time Ts exceeds the target time Ta, then processing proceeds to S604 where a correction is made in accordance with the pressure increasing characteristic of the common rail pressure Pc is performed. Here are S604 and S606 steps for determining the pressure increasing characteristic.

at S604, it is determined whether the pressure increasing characteristic ΔPc / ΔT (actual Value of ΔPc / ΔT), at S602 was calculated, is greater than a predetermined upper increase threshold (upper Limit) UL at the side of an upper limit of a range of Pressure increase characteristic ΔPc / ΔT (allowable range of ΔPc / ΔT) in which in advance based on an experiment or the same has been ensured that ensures the predetermined starting assets can be. If the actual Value ΔPc / ΔT is greater than the upper limit value UL, then the drive amount D (pulse duration ratio the pulse duration control) increases at S605 (D1 = D1 + ΔD), and the control processing will be terminated. On the contrary, if the actual value ΔPc / ΔT is smaller as the upper limit value UL, the processing proceeds to S606 further.

at S606, it is determined whether the actual value ΔPc / ΔT is smaller is as a predetermined lower increase threshold (lower limit) LL at a lower limit side of the allowable range of ΔPc / ΔT. If the actual Value of ΔPc / ΔT smaller is the lower limit value LL, then the drive amount D becomes (Duty ratio) reduced at S607 (D1 = D1 - ΔD), and the Control processing is terminated. In contrast, if the actual Value ΔPc / ΔT is greater as the lower limit value LL, then the control processing becomes completed.

If the actual value of ΔPc / ΔT is greater than the upper limit UL (for example, a dashed line at S602 (b) in FIG 6 according to the comparison and determination of the pressure increasing characteristic (the actual value of ΔPc / ΔT) in the above-mentioned steps S604 and S606 with respect to the lower limit by making a correction (D1 = D1 + ΔD) so as to set the driving amount D of the Einspritzdrucksteuersolenoidventils 19 To increase the output setting, the discharge at the next startup can be reduced. On the other hand, if the actual value of ΔPc / ΔT is smaller than the lower limit value (for example, one by a two-dot chain line in S602 (b) in FIG 6 by performing a correction (D1 = D1 - ΔD) so as to control the driving amount D of the injection pressure control solenoid valve 19 To reduce the output setting, the output may be increased at the next startup. The driving amount D corrected as described above is stored in a memory as a learning value so that it can be used next time (S601 in the next engine starting operation).

In this way, it is possible to perform correction of the driving amount D in the next engine starting operation, namely to continuously perform learning control for each starting operation until the time Ts becomes smaller than the target starting time Ta until the predetermined starting capability is ensured , Thus, it is possible to have the predetermined starting capability of the internal combustion engine regardless of the change between the high-pressure pumps 7 to ensure.

Second Embodiment

In the second embodiment according to the 7 is determined whether the achieved speed N1 (actual speed of the internal combustion engine) reaches a target speed of the internal combustion engine Na, when a predetermined time T1 has elapsed after the start. The 7 Fig. 10 shows a flowchart of the high pressure pump start control processing 700 , The in the 7 The high pressure pump start control shown is the control processing according to the collection type fuel injection device used in the first embodiment (FIG. 1 and 2 ), and as the preprocessing in this high-pressure pump starting control, like in the first embodiment, control processing for detecting a start operation by the start detecting unit for supplying a current to the starting apparatus is performed (S501 in FIG 5 ).

Like this in the 7 is shown in the high-pressure pump start control processing 700 the control processes are performed at S601 and S702 to S706.

The driving amount D of the injection pressure control solenoid valve 19 the high pressure pump 7 is set as the predetermined value D1 by the control processing at S601 ( 6 ), and then, at S702, the actual rotational speed of the engine N1 is detected when the predetermined time T1 has elapsed after the start of the engine ((a) in FIG 7 ). Further, when the predetermined time T1 has elapsed, then the achieved fuel pressure (actual fuel pressure) Pc1 of the common rail pressure Pc by the fuel pressure sensor 81 detected.

By detecting a start of the power supply to the starting device by detecting a timing when the starter-on signal from the OFF state to the ON state is changed, that timing is detected at which the drive operation the starting device was started to the internal combustion engine to start.

at S703, it is determined whether or not the actual detected at S702 Speed of the internal combustion engine N1 a predetermined speed of Internal combustion engine (target speed of the internal combustion engine) Na (zum Example exceeds 400 rpm). If the actual Speed N1 exceeds the predetermined speed Na, then the Control processing completed. If, in contrast, the actual speed N1 does not exceed the predetermined rotational speed Na, then proceeds control processing proceeds to S704.

At S704, to make a correction to ensure the predetermined starting capability, the actual engine speed N1 and the actual fuel pressure Pc1 in the ECU 10 is stored as current data indicating the starting capability of the internal combustion engine at the time when a predetermined time T1 has elapsed, and the processing proceeds to S705.

At S705 and S706, the initial value D1 of the driving amount D is corrected to a predetermined initial value (target driving amount) Da, that for the high-pressure pump mounted on the engine 7 is suitable (D1 is replaced by Da) using the actual rotational speed N1 and the actual fuel pressure Pc1 with reference to data stored in advance for the correction. At S705, a target fuel pressure Pca is determined so that the actual rotational speed N1 becomes the target rotational speed of the engine Na at the next startup using the actual rotational speed N1 and the actual fuel pressure Pc1. At S701, the target driving amount Da at the next starting operation is determined by the target fuel pressure Pca.

Specifically, at S705, the target fuel pressure Pca corresponding to the actual rotational speed N1 is determined, as shown in the graph at S705, from a correlation of the fuel pressure Pc and the rotational speed N1 at the starting operation. Here, a method of calculating the target fuel pressure Pca may be any method using a map or a calculation formula. The map may include any one-dimensional map of the actual engine speed N1, a two-dimensional map of the actual engine speed N1 and the fuel temperature TF detected by the fuel temperature sensor 81 and a three-dimensional map of the actual rotational speed N1, the actual fuel pressure Pca, and the fuel temperature TF. Further, the calculation formula may be any function such as Pca = f (N1) with the actual rotational speed N1 as a variable, a function Pca = f (N1, t) with the actual rotational speed N1 and the fuel temperature TF as variables and a function Pca = f (N1, Pc1, TF) with the actual rotational speed N1, the actual fuel pressure Pc1 and the fuel temperature TF as variables.

Compared with a method for determining the target fuel pressure Pca exclusively the actual Speed N1 may be the method for calculating the target fuel pressure Pca with further consideration the effect of the fuel temperature TF improve the accuracy of calculation and the method of calculating the target fuel pressure Pca further consideration the fuel temperature and the actual fuel pressure Pc1 generated by the fuel temperature can continue the calculation accuracy improve. By calculating the target pressure Pca under consideration the fuel temperature TF, it is also possible to start the engine at Start at low temperature to ensure.

at S706 is calculated from the correlation between the fuel pressure Pc and the drive amount (pulse duration ratio) D at the start, such as this is shown in the graph at S706, the target driving amount (target pulse width ratio) Da accordingly the target fuel pressure Pca determined. In this regard, the method for Calculate this target drive amount Da a procedure under Use a picture, such as a one-dimensional Illustration of the target fuel pressure Pca, a two-dimensional map of the target fuel pressure Pca and the fuel temperature TF, a three-dimensional picture the target fuel pressure Pca, a fixed drive amount D1 at the start and the fuel temperature TF or a procedure using a calculation formula such as a function Da = f (Pca) with the target fuel pressure Pca as a variable, a Function Da = f (Pca, t) with the target fuel pressure Pca and the Fuel temperature TW as variables and a function Da = f (Pca, D1, t) with the target fuel pressure Pca, the fixed drive amount D1 and the fuel temperature TW as variables.

In this way, the output the high-pressure pump in the next startup to a suitable output for the internal combustion engine with the attached high-pressure pump 7 be corrected, and thus can the effect of changes under the high pressure pumps 7 (More specifically, the changes of the discharge among the injection pressure control amount control valves 19 ) are reduced in terms of starting ability. As a result, it is possible to ensure a predetermined startability. For example, it is possible to ensure the predetermined starting capability by checking the target driving amount Da for each starting operation and correcting the driving amount D1 for starting.

at the high pressure pump start control processing S700 works in the control processing S702 and S703 as a start-up determining unit, which determines if the actual speed N1 reaches the target speed Na when the internal combustion engine starts and then a predetermined time T1 has elapsed. To this Way, it is possible with a method for determining the start-up capacity, the startability determine even if the boot process is not completed, even in a transitional state while the starting process such as in the drive state of the Internal combustion engine, in which the speed of the engine comparatively is low, namely right after the start of the engine. The starting asset determination unit can determine or she can make a predictive determination, whether the predetermined starting ability guaranteed can be by the actual Speed N1 at the time when the predetermined time T1 elapsed is compared with the target speed Na and determined from this becomes.

The start-up determination is made using the drive condition detection sensor group 70 and an engine start command detection. This allows the start-up determining unit to easily detect the starting operation of the internal combustion engine and thus to surely compare the actual rotational speed N1 with the target rotational speed Na, even if the predetermined time T1 elapsed after the starting operation is shortened to a certain extent , Thus, by using the starting-property determining unit, it is possible to make a determination for ensuring the starting capability even in the transient state immediately after the starting operation of the internal combustion engine.

The control processes in S704 to S706 constitute an ejection correction unit for correcting the ejection D1 at the next startup in response to the actual fuel pressure Pc1 and the actual rotational speed N1 at the predetermined elapsed time T1. By this ejection correction unit, it is possible to improve the startability and thus the predetermined startability regardless of the changes among the high pressure pumps 7 to ensure.

In this regard, the correction of the ejection D1 is performed by the ejection correcting unit in the case where the start-up determining unit determines that the actual rotational speed N1 does not reach the target rotational speed Na. For this reason, it is possible as compared with the case where the correction of the discharge is performed regardless of whether the actual rotational speed N1 is larger or smaller than the target rotational speed Na, to reduce the load of the ejection correction unit, namely, the load of the ECU 10 ,

in this connection may the target speed Na any speed of the internal combustion engine provided that it is within a range of speeds which during the Drive state from the start of the boot process to completion of the boot process occur.

(Third Embodiment)

In the third embodiment according to the 8th There is provided a cylinder discrimination unit for discriminating the cylinders of the internal combustion engine and a control unit which can control the exhaust D for each cylinder. The 8th FIG. 10 shows a flowchart of the high-pressure pump according to the present embodiment. FIG.

The cylinder discrimination unit has the crank angle sensor 77 and the speed sensor 71 ( 2 ). For example, the cylinder discriminating unit is a well known unit in which one signal per revolution of the high pressure pump 7 through the crank angle sensor 77 is sent, and a plurality of signals (for example 60 in the case of four cylinders, which is a multiple of four) per revolution of the high-pressure pump 7 through the speed sensor 71 Posted. The ECU 10 picks up these signals and determines a specific cam phase 8th (not shown) corresponding to a specific cylinder of the high-pressure pump 7 ,

The Control unit is a well-known unit for controlling the discharge D according to the cylinder, which was distinguished by the cylinder discriminating unit.

Like this in the 8th is shown, it is determined at S801 whether the cylinder can be discriminated by the cylinder discriminating unit. More specifically, it is determined whether the signal coming from at least the crank angle sensor 77 or the Speed sensor 71 is greater than a predetermined signal output (detectable threshold). If the signal output is larger than the detectable threshold value, then it is determined that the cylinder can be discriminated, and the processing proceeds to S802. In contrast, the processing proceeds to S700 when the signal output is smaller than the detectable threshold value. In this regard, a determination criterion of whether the cylinder can be discriminated is not limited to the above-mentioned threshold value, but a lower limit rotational speed of the internal combustion engine may be provided at which these signal outputs can be detected.

at S802 becomes the relationship between that by the cylinder determination unit certain engine and specific cylinder Cam phase corresponding to the cylinder of the discharge D controlled according to the cylinder.

On the other hand, at S700, the high pressure pump start control described in the second embodiment is performed. Namely, the predetermined driving amount D1 is input as the driving amount D at the starting operation, and the setting of the discharge of the high-pressure pump 7 in response to the driving amount D1 is performed, and the target driving amount Da in the next starting operation is determined by the start-up determining unit and the ejection correcting unit. Then, the processing proceeds to S802.

If it is determined by the start determination unit that the actual rotation speed N1 reaches the target rotation speed Na, then the discharge correction unit does not perform correction, but the control unit performs control of the discharge according to the cylinder. In this way, it is possible to provide a learning control for making a correction in terms of the changes among the high-pressure pumps 7 in the next start-up operation until the start-up determining unit determines that the predetermined start-up capability is ensured.

If Further, it is determined that the actual rotational speed N1 is the target rotational speed Well achieved and that the predetermined starting power is guaranteed, then it is possible, a correction not for the next Starting process but to improve the starting power during the Startup procedure. For example, it is possible effectively the starting power to improve in the range of the speed of the internal combustion engine, which exceeds the target speed Na, in response to the set value of the target speed N / A. In this regard, Is it possible, effectively the starting power in the range of the speed of the internal combustion engine to improve exceeds the target speed of the internal combustion engine Na, by the regulation, even if the start-up determining unit is not determines that the predetermined starting capability is ensured.

Here, in the present embodiment, the target rotational speed Na is set to a value smaller than a lower limit rotational speed Nj ((a) at S702 in FIG 7 ), in which the cylinder can be distinguished by the cylinder discriminating unit. In this way, it is possible to perform the learning control for performing a correction in the next startup operation and the control for performing a correction for improving the startup capability during the startup operation, and thus to effectively ensure the predetermined startup capability. In this regard, it is desirable that the target rotational speed Na is near the lower limit rotational speed.

A collecting fuel injection device has a high-pressure pump ( 7 ), a common rail ( 5 ) for collecting high pressure fuel passing through the high pressure pump ( 7 ) and an ECU ( 10 ) for controlling the output of the high pressure pump ( 7 ) in response to the driving state of an engine and the common rail pressure (Pc). When the engine is started, the ECU ( 10 ) a time (Ts) that elapses before the engine speed reaches a predetermined speed (Ns), and a pressure increase characteristic (ΔP / ΔT) of the common rail pressure (Pc), and when the elapsed time (Ts) has a target speed Start time (Ta) exceeds, then increases or decreases the output (D) in the next engine starting operation in response to the pressure increase characteristic (.DELTA.P / .DELTA.T).

Claims (12)

A collective fuel injection device comprising: a high pressure pump ( 7 ) for sucking fuel from a fuel tank ( 6 ); a common rail ( 5 ) for collecting high pressure fuel expelled by the high pressure pump; a plurality of fuel injection valves ( 1 to 4 ), which are respectively mounted on a respective cylinder of an internal combustion engine and inject the high-pressure fuel collected in the common rail into a combustion chamber of the cylinder; a drive condition detection unit ( 70 ) for detecting a driving state of the internal combustion engine; a fuel pressure detection unit ( 81 ) for detecting a fuel pressure of the in the Com mon-rail high-pressure fuel collected; and an exhaust control unit ( 10 , S605, S607) for controlling discharge of the high-pressure pump in response to the driving state detected by the driving state detecting unit and the fuel pressure detected by the fuel pressure detecting unit, characterized in that when the internal combustion engine is started, the discharge control unit (FIG. 10 , S605, S607) detects a time (Ts) that elapses before the engine speed (N) reaches a predetermined speed (Ns), and detects a pressure increasing characteristic (.DELTA.Pc / .DELTA.T) of the fuel pressure by the fuel pressure detecting unit, and if Time exceeds a predetermined start time, then increases or decreases the output in the next engine starting operation according to the pressure increase characteristic. A collective fuel injection device according to claim 1, further characterized in that the high pressure pump is a quantity control valve ( 19 ) for adjusting an amount of fuel sucked from the fuel tank, and wherein the exhaust control unit changes a driving amount (D) delivered to the quantity control valve. Collective fuel injection device according to claim 2, further characterized in that the quantity control valve is a linear solenoid valve. Collective fuel injection device according to claim 2 or claim 3, further characterized in that the delivered to the quantity control valve drive amount by a pulse duration control is controlled, and the fuel output in the next starting operation of the internal combustion engine elevated when the pressure increasing characteristic is less than a predetermined value. Collective fuel injection device according to a the claims 2 to 4, further characterized in that the pressure increasing characteristic an increase of the fuel pressure per unit time, and the exhaust control unit a predetermined upper increase threshold (UL) and a predetermined lower increase threshold (LL), and when the pressure increasing characteristic greater than or equal to the predetermined upper increase limit, then increases the amount of drive and when the pressure increasing characteristic less than or equal to the predetermined lower increase threshold is, then it reduces the drive amount. A collective fuel injection device comprising: a high pressure pump ( 7 ) for sucking fuel from a fuel tank ( 6 ); a common rail ( 5 ) for collecting high pressure fuel expelled by the high pressure pump; a plurality of fuel injection valves ( 1 to 4 ), which are mounted on a respective cylinder of an internal combustion engine and inject the high-pressure fuel collected in the common rail into a combustion chamber of the cylinder; a fuel pressure detection unit ( 81 ) for detecting a fuel pressure of the high-pressure fuel collected in the common rail; and an exhaust control unit ( 10 ) for controlling discharge of the high-pressure pump in response to the fuel pressure detected by the fuel pressure detection unit, further characterized by a start-up determining unit (Fig. 10 , S703) which determines whether the engine speed (N1) reaches a predetermined speed (Na) when a predetermined time (T1) has elapsed after the engine is started; and an ejection correction unit ( 10 , S705, S706) for correcting the discharge at the next starting operation in response to an actual fuel pressure detected by the fuel pressure detecting unit at elapse of the predetermined time and an actual engine speed compared with the predetermined engine speed by the starting capability determining unit. Collective fuel injection device according to claim 6, further characterized in that when the start-up determining unit determines that the speed of the internal combustion engine, the predetermined speed not reached, the ejection correction unit Corrected the output. The collective fuel injection device according to claim 6 or claim 7, further characterized in that the start-up determining unit comprises a driving condition detecting unit (10). 70 ) for detecting a driving state of the internal combustion engine and an engine start command detecting unit for detecting an instruction for starting the internal combustion engine. A collection fuel injector according to any of claims 6 to 8, further characterized in that the high pressure pump is a quantity control valve ( 19 ) for adjusting an amount of fuel sucked from the fuel tank, wherein the exhaust control unit changes an amount of driving output to the quantity control valve, and the ejection correction unit corrects the driving amount to the driving amount suitable for the high pressure pump mounted on the engine using the actual fuel pressure and the actual speed of the internal combustion engine with reference to data that has been stored for the correction in advance. A collective fuel injection device according to any one of claims 6 to 9, further characterized by a cylinder discrimination unit ( 10 , S801) for discriminating the cylinders and a control unit (S802) for controlling the discharge according to the cylinder discriminated by the cylinder discriminating unit. Collective fuel injection device according to claim 10 further characterized in that when the start-up determining unit determines that the speed of the internal combustion engine, the predetermined Speed reached, the Ausstoßkorrektureinheit does not correct and the control unit controls the output according to the cylinder. Collective fuel injection device according to claim 10 or claim 11, wherein the predetermined speed of the internal combustion engine is less than a lower limit speed through which the cylinder is distinguishable by the discriminating unit.