DE102013106061A1 - An abnormality determination device and an abnormality determination method for a fuel injector - Google Patents

Abstract

An abnormality determination device includes a parameter calculation section (70) that calculates parameters that identify an injection rate waveform with respect to the adjustment point based on the pressure waveform detected by the pressure waveform detection section (70); a difference calculation section (70) that calculates a difference between the parameter calculated by the parameter calculation section and a parameter that identifies a predetermined reference injection rate waveform; and an abnormality determination section (70) that determines whether the fuel injector (10) has an abnormality based on the difference calculated by the difference calculation section with respect to each of the parameters. When the abnormality determination section determines that the fuel injector (10) has the abnormality, the abnormality determination section determines a kind of the abnormality of the fuel injector (10) based on the parameter whose value exceeds a threshold value.

Description

TECHNICAL AREA

The present invention relates to an abnormality determination apparatus and an abnormality determination method for a fuel injector that are applied to a fuel injection system for an internal combustion engine.

BACKGROUND

The JP 2009 74536 A ( EP 2031226 A2 10 shows an abnormality determination method in which a deviation of a fuel pressure and a deviation of a fuel injection rate due to fuel injection are detected before a fuel injector is delivered. By comparing a detection delay time with a reference time, it is determined whether there is an abnormality in a fuel injector or a fuel pressure sensor. The detection delay time represents a time period from which a fuel injection control apparatus is turned ON until a deviation of the fuel pressure is actually detected. Subsequently, when it is determined that there is an abnormality, it is determined whether the fuel injector is abnormal or the fuel pressure sensor is abnormal by comparing an injection start delay time and a reference time. The injection start delay time represents a period from which the fuel injection drive signal is turned ON until the deviation of the fuel injection rate is actually detected.

Although it is determined in the above-mentioned method whether the fuel injector is abnormal or the fuel pressure sensor is abnormal, it is not determined what kind of abnormality exists in the fuel injector.

SHORT VERSION

It is an object of the present invention to provide an abnormality determination apparatus and an abnormality determination method in which the type of abnormality of a fuel injector can be determined.

An abnormality determination apparatus is applied to a fuel injection system including a fuel injector that injects fuel into a machine through a nozzle orifice. The abnormality determination device includes a parameter calculation section that calculates a parameter that identifies an injection rate waveform with respect to a fitting point. The injection rate waveform represents a deviation of an injection rate of the fuel injected by the fuel injector. The adjustment point is defined by an injection amount of the fuel and a pressure of the fuel supplied to the fuel injector.

The abnormality determination device further comprises a difference calculation section for calculating a difference between the parameter calculated by the parameter calculation section and a parameter identifying a predetermined reference injection rate waveform; and an abnormality determination section that determines whether the fuel injector has an abnormality based on the difference calculated by the difference calculation section with respect to each of the parameters.

When the abnormality determination section determines that the fuel injector has the abnormality, the abnormality determination section determines a type of the abnormality of the fuel injector based on the parameter whose value exceeds a threshold value.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings show:

1 a schematic diagram illustrating a fuel injection system;

2 12 is a schematic diagram illustrating an abnormality determination test of a fuel injector according to a first embodiment;

3 FIG. 15 is a graph showing a deviation of the fuel pressure and an injection rate parameter corresponding to a fuel injection command signal; FIG.

4 FIG. 15 is a graph showing a relationship between an injection rate parameter and the type of abnormality of a fuel injector; FIG. and

5 12 is a schematic diagram illustrating an abnormality determination test of a fuel injector according to a second embodiment.

DETAILED DESCRIPTION

First Embodiment

Regarding 1 FIG. 14 is an outline of a fuel injection system to which an abnormality determination device is attached. FIG. The Fuel injection system is applied to a diesel engine. The fuel injection system consists of a fuel injector 10 , which is attached to a cylinder, a fuel pressure sensor 20 detecting fuel pressure applied to the fuel injector 10 is fed to an ECU 30 and a fuel tank 40 together.

The fuel tank 10 serves to store the fuel (light oil) that is fed to each cylinder. The fuel in the fuel tank 50 is pressurized and by a fuel pump 41 , which is driven by the machine, a manifold 42 fed. The fuel pressure in the manifold 42 corresponds to a supply pressure Pc of the fuel that is the fuel injector 10 is supplied. The fuel which is in the manifold 42 is collected, the fuel injector 10 through a fuel inlet 11f fed.

The fuel injector 10 is made up of a body 11 , a needle valve 12 (Tip sliding section) and an actuator 13 (Drive section) together. The body 11 defines a high pressure channel 11a and a low pressure channel 11d , Likewise, the body defines a nozzle orifice 11b that with the high pressure passage 11a connected is. The fuel coming from the manifold 42 is supplied through the high pressure passage 11a from the nozzle mouth 11b injected into a cylinder.

Further, the body defines 11 at its end portion a high pressure chamber 17 , The high pressure chamber 17 is between an outer surface of the needle valve 12 and an inner surface of the body 11 educated. When the needle valve 12 is moved in a valve opening direction, is the high-pressure chamber 17 with the nozzle mouth 11b in connection. Further, the body defines 11 a back pressure chamber 16 to counter pressure on the needle valve 12 and a control chamber 15 to the fuel pressure in the back pressure chamber 16 to control. The control chamber 15 stands with the high pressure channel 11a , the low pressure channel 11d and the back pressure chamber 16 in connection. A connection condition between the high pressure passage 11a , the low pressure channel 11d and the control chamber 15 is through a control valve 14 switched over in the control chamber 15 is arranged.

The needle valve 12 is in the body 11 added. The needle valve 12 assumes a fuel pressure corresponding to a differential pressure between the fuel pressure in the high pressure chamber 17 and the fuel pressure in the back pressure chamber 16 equivalent. When the absorbed pressure is greater than an applied force of a nozzle spring 16a will open the needle valve 12 the nozzle mouth 11b ,

The actuator 13 is a piezo actuator composed of a plurality of piezoelectric elements. In accordance with an excitation condition of the piezoelectric elements, an axial length of the actuator varies 13 , When the actuator 13 receives a drive signal, generates the actuator 13 therefore a driving force down in 1 ,

When the actuator 13 is energized, the cylinder becomes 19 against the applied force of a piezo spring 18 moved down. The control valve 14 is through the cylinder 19 on a high-pressure seat surface 15a crowded. Here are the control chamber 15 and the back pressure chamber 16 with the low pressure channel 11d in conjunction, allowing the high-pressure fuel in the control chamber 15 and the back pressure chamber 16 in the high pressure channel 11d flows. The fuel pressure in the back pressure chamber 16 decreases. As a result, the fuel pressure acting on the needle valve 12 is applied, greater than the applied force of the nozzle spring 16a , and a seat surface 12a of the needle valve 12 moves from the seat surface 11e of the body 11 path. The fuel gets out of the nozzle mouth 11b injected. The fuel in the low pressure passage 11d flows, returns through a fuel outlet 11g in the fuel tank 40 back.

If now the actuator 13 is not energized, becomes the control valve 14 with a low pressure seat surface 15b brought into contact, as in 1 is shown. Here are the control chamber 15 and the back pressure chamber 16 with the high pressure channel 11a in connection. High pressure fuel enters the control chamber 15 and the back pressure chamber 16 initiated. As the fuel pressure on the needle valve 12 is applied, smaller than the applied force of the nozzle spring 16a becomes, becomes the seat surface 12a of the needle valve 12 consequently with the seat surface 11e of the body 11 brought into contact, so that a fuel injection is terminated.

As mentioned above, in the control chamber 15 the fuel pressure acting on the needle valve 12 is applied, controlled by the driving force, which the actuator 13 generated. The needle valve 12 opens and closes the nozzle mouth 11b consistent with the applied fuel pressure.

The fuel pressure sensor 20 is made up of a shaft 21 and a pressure sensor element 22 together. The shaft 21 is on the body 11 attached and has a membrane portion 21a on. The membrane section 21a can be caused by the high-pressure fuel passing through the high-pressure channel 11a flows, be elastically deformed. The pressure sensor element 22 is at the membrane portion 21a attached to a pressure detection signal to the ECU 30 transferred to. The pressure detection signal depends on an elastic deformation of the diaphragm portion 21a from.

The ECU 30 is a microcomputer having a CPU and a memory (ROM, RAM). The ECU 30 calculates a target fuel injection condition based on an accelerator pedal position, engine load, and engine speed. For example, the microcomputer stores an optimal fuel injection condition with respect to the engine load and the engine speed into a fuel injection condition map. Subsequently, based on the current engine load and the engine speed, the target fuel injection condition with respect to the fuel injection condition map is calculated.

Regarding 2 becomes an abnormality determination test of the fuel injector 10 described below. The abnormality determination test is performed in a factory before delivery or in a service factory after delivery. This abnormality determination test becomes a fuel injector 10 , a fuel pressure sensor 20 , a pump 71 for an experiment to supply high pressure fuel to a fuel injector 10 and a measuring instrument 70 used.

The meter 70 is equipped with a control unit (a pressure waveform detection section, a parameter calculation section, a difference calculation section, and an abnormality determination section), and includes a microcomputer. First, represents the control unit of the meter 70 based on an injection amount Q and a supply pressure Pc on a matching point. The pump 71 leads the fuel with the supply pressure Pc to the fuel inlet 11f of the fuel injector 10 to. The control unit of the measuring instrument 70 transmits a control signal corresponding to the injection amount Q to the fuel injector 10 to the fuel injector 10 head for. The fuel pressure sensor 20 detects the fuel pressure with which the fuel injector 10 injects. The detected fuel pressure is applied to the measuring instrument 70 transfer.

The control unit of the measuring instrument 70 detects a deviation of the fuel pressure as a fuel pressure waveform Wb based on the detection value of the fuel pressure sensor 20 , Thereafter, the control unit calculates, based on the detected pressure waveform Wb, the injection rate parameters "Rmax", "td", "te" which set an injection rate waveform. The injection rate waveform represents a deviation of the injection rate with respect to time. Further, the control unit calculates a difference between the calculated injection rate parameters "Rmax", "td", "te" and the reference injection rate parameters "Rmaxm", "tdm", "tem", respectively. , The reference injection rate parameters set a reference injection rate waveform stored in a memory.

The control unit of the measuring instrument 70 determined based on the difference between the parameters, whether the fuel injector 10 is abnormal. Further, when the control unit determines that there is an abnormality, the control unit determines the type of the abnormality based on the parameter exceeding a threshold value. Hereinafter, an operation for calculating injection rate parameters "Rmax", "td", "te", and a procedure for determining the type of abnormality of the fuel injector will be described 10 described in detail.

Regarding 3 a procedure is described in which the driving section of the measuring instrument 70 calculated the injection rate parameter based on the detected pressure waveform Wb. 3 (a) shows the drive signal of the fuel injector 10 . 3 (b) shows the injection rate waveform and 3 (c) shows the pressure waveform Wb.

In the pressure waveform Wb, a descending pressure waveform from a point P1 to a point P2 is approximated by a least squares method to a descending straight line Lα. At point P2, a drop in fuel pressure ends. Thereafter, a time LBα is calculated at which the fuel pressure assumes a reference value Bα on the approximate falling straight line Lα. Based on the calculated time LBα, an injection start time R1 is calculated. More specifically, a time which is a certain time delay Cα before the time LBα is defined as the fuel injection start time R1.

Further, an increasing pressure waveform from a point P3 to a point P5 is approximated by a least squares method to a rising straight line Lβ. At the point P3, the fuel pressure starts to increase due to a change of fuel injection. At the point P5, an increase in the fuel pressure ends. Thereafter, a time LBβ at which the fuel pressure assumes a reference value Bβ on the approximate rising straight line LBβ is calculated. Based on the calculated time LBβ, a fuel injection end time R4 is calculated. More specifically, a time which is a certain time delay Cβ before the time LBβ is defined as the fuel injection end time R4.

Subsequently, a slope of a straight line Rα, which is an increase in the injection amount is calculated based on a slope of the approximate descending straight line Lα. Specifically, an inclination of the approximate descending straight line Lα is multiplied by a certain coefficient to obtain the slope of the straight line Rα. Similarly, a slope of a straight line Rβ indicating a decrease in the injection amount is calculated based on a slope of the approximate rising straight line Lβ.

Subsequently, an intersection point of both straight lines Rα and Rβ is calculated. The overlap point is defined as the valve closing start time R23. At the time R23, the needle valve starts 12 lower down together with a fuel injection end command signal. Further, the control unit calculates a delay time (injection start delay time "td") of the fuel injection start time R1 in relation to a drive start time t1 and a delay time (injection end delay time "te") of the fuel injection end time R4 in relation to an injection end command time "t2". It should be noted that a delay time of the valve closing start time R23 in relation to an injection end command time "t2" may be used as the injection end delay time "te".

An intersection of the descending straight line Lα and the rising straight line Lβ is obtained, and a pressure corresponding to this intersection is calculated as an intersecting pressure Pαβ. Further, a differential pressure ΔPγ between a reference pressure Pbase and the overlap pressure Pαβ is calculated. The reference pressure Pbase is an average fuel pressure of the fuel pressure waveform Wb until the fuel pressure starts to decrease. Based on the calculated differential pressure ΔPγ, a maximum injection rate Rmax is calculated. Specifically, the differential pressure ΔPγ is multiplied by a correlation coefficient Cγ to calculate the maximum injection rate Rmax. If the differential pressure ΔPγ is smaller than a predetermined value ΔPγth (small injection), the maximum fuel injection rate Rmax is defined as follows: Rmax = ΔPγ × Cγ

If the differential pressure ΔPγ is not smaller than the predetermined value ΔPγth (large injection), a predetermined value Rγ is defined as the maximum injection rate Rmax.

The small injection corresponds to a case where the needle valve 12 begins to descend before the injection rate reaches the predetermined value Rγ. The amount of fuel injection is through the seating surfaces 11e and 12a limited. Meanwhile, the large injection corresponds to a case where the needle valve 12 begins to descend downward after the injection rate has reached the predetermined value Rγ. The fuel injection amount depends on a flow area of the nozzle orifice 11b from. That is, when a drive duration of the injection command period "Tq" is long enough, and the injection port 11b has been opened, even after the maximum injection rate Rmax is reached, the shape of the injection rate waveform becomes trapezoidal, as in FIG 3 (b) is shown. Meanwhile, in the case of the small injection, the shape of the injection rate waveform becomes triangular. In the present embodiment, the shape of the injection rate waveform is trapezoidal.

As described above, the injection rate parameters "Rmax", "td", "te" can be calculated from the fuel pressure waveform Wb.

Hereinafter, a procedure will be described in detail, in which the control portion of the measuring instrument 70 determines if an abnormality of the fuel injector 10 and the control section determines the type of abnormality using the injection rate parameters "Rmax", "td", "te".

First, the driving section reads out the injection rate parameters "Rmaxm", "tdm", "tem" from the memory. These parameters set the reference injection rate waveform that corresponds to the established adjustment point.

In the case of the large injection, there is a correlation between the maximum injection rate Rmax and an area of the nozzle orifice 11b , D. h., When the area of the nozzle orifice 11b becomes larger, the maximum injection rate Rmax becomes larger. If the area of the nozzle orifice 11b becomes smaller, the maximum injection rate Rmax becomes smaller. Therefore, based on a difference between "Rmax" and "Rmaxm", the control section may abnormality the nozzle orifice 11b of the fuel injector 10 determine.

Further, several types of fuel injector abnormality tend 10 to appear in the injection start delay time "td" and an injection end delay time "te". Therefore, based on a difference between "td" and "tdm" and a difference between "te" and "tem", the control unit may determine the kind of abnormality of the fuel injector 10 determine with high accuracy.

As described above, the control unit calculates each difference as follows: ΔRmax = Rmax - Rmaxm Δtd = td - tdm Δte = te - tem

• (1) Wenn die Differenz ΔRmax größer als der Schwellwert ”Thr” (|ΔRmax| > Thr) ist, kann die Steuereinheit bestimmen, dass ein Durchmesser der Düsenmündung 11b anormal ist. Wenn die Steuereinheit bestimmt, dass die Düsenmündung 11b des Kraftstoffinjektors 10 anormal ist, wird die Düsenmündung des Kraftstoffinjektors 10 durch eine neue ersetzt.
• (2) Wenn die Differenz Δtd größer als der Schwellwert ”Thd” ist und die Differenz Δte größer als der Schwellwert ”The” ist, kann abgeschätzt werden, dass eine Bewegungsgeschwindigkeit des Nadelventils 12 verlangsamt ist. Wenn um das Nadelventil 12 herum ein Fremdkörper vorliegt, nimmt ein Spalt um das Nadelventil 12 herum ab und der Bewegungswiderstand des Nadelventils 12 nimmt zu. Daher wird in diesem Fall die Art der Anormalität als ein vorliegender Fremdkörper um das Nadelventil herum 12 bestimmt. Ein Spitzenabschnitt des Kraftstoffs Injektors 10 wird zerlegt, um ausgewaschen zu werden, so dass ein Fremdkörper von dem Spalt um das Nadelventil 12 herum entfernt wird.
• (3) Wenn die Differenz Δtd größer als der Schwellwert ”Thd” ist und die Differenz Δte kleiner als ”–The” ist, kann abgeschätzt werden, dass eine Kraft zum Anheben des Nadelventils 12 von der Düsenmündung 11b klein ist, wenn das Ansteuersignal EIN ist. Die Kraft zum Anheben des Nadelventils 12 wird durch das Stellglied 13 erzeugt. In diesem Fall kann somit bestimmt werden, dass die Ansteuerkraft des Stellglieds 13 beeinträchtigt ist. Das Stellglied 13 wird durch ein neues ersetzt.
• (4) Wenn die Differenz Δtd kleiner als ”–Thd” ist und die Differenz Δte kleiner als ”–The” ist, kann abgeschätzt werden, dass eine Reaktionsgeschwindigkeit des Nadelventils 12 zu dem Ansteuersignal erhöht ist. Wenn ein Fremdkörper in die Steuerkammer 15 eingeführt wird und ein Volumen der Steuerkammer 15 herabgesetzt ist, wird eine Abweichung der Geschwindigkeit des Kraftstoffdrucks erhöht, der auf das Nadelventil 12 wirkt. Wenn das Volumen der Steuerkammer 15 herabgesetzt ist und das Ansteuersignal EIN-geschaltet wird, ist eine Abweichung der Geschwindigkeit des Kraftstoffdrucks auf einen niedrigeren Wert in der Gegendruckkammer 16 höher. Wenn das Ansteuersignal AUS-geschaltet wird, ist die Abweichung der Geschwindigkeit des Kraftstoffdrucks auf einen höheren Wert höher. In diesem Fall kann daher die Art der Anormalität als ein vorliegender Fremdkörper in der Steuerkammer 15 bestimmt werden. Die Steuerkammer 15 wird zerlegt, um ausgewaschen zu werden, so dass ein Fremdkörper aus der Steuerkammer 15 entfernt wird.

Thereafter, based on the above differences "ΔRmax", "Δtd", "Δte", the control unit determines whether abnormality in the fuel injector 10 is present. In particular, the differences "ΔRmax", "Δtd", "Δte" are each compared with the threshold values "Thr", "Thd", "The". If the difference exceeds the threshold, the controller determines that the fuel injector 10 is abnormal. If the control unit determines that there is an abnormality to the fuel injector 10 is present, the control unit further determines the type of abnormality based on the injection rate parameter exceeding the threshold value. 4 FIG. 15 is a graph showing a relationship between the above-mentioned differences "ΔRmax", "Δtd", "Δte" and the type of abnormality. It should be noted that the threshold values "Thr", "Thd", "The" are positive values.

• (1) When the difference ΔRmax is greater than the threshold value "Thr" (| ΔRmax |> Thr), the control unit may determine that a diameter of the nozzle orifice 11b is abnormal. When the control unit determines that the nozzle orifice 11b of the fuel injector 10 is abnormal, the nozzle orifice of the fuel injector 10 replaced by a new one.
• (2) If the difference Δtd is larger than the threshold value "Thd" and the difference Δte is larger than the threshold value "The", it can be estimated that a moving speed of the needle valve 12 is slowed down. If around the needle valve 12 There is a foreign body around, takes a gap around the needle valve 12 around and the resistance of the needle valve 12 is increasing. Therefore, in this case, the type of abnormality becomes as a foreign matter around the needle valve 12 certainly. A top section of the fuel injector 10 is disassembled to be washed out, leaving a foreign body from the gap around the needle valve 12 is removed around.
• (3) When the difference Δtd is larger than the threshold value "Thd" and the difference Δte is smaller than "-The", it can be estimated that a force for lifting the needle valve 12 from the nozzle mouth 11b is small when the drive signal is ON. The force to lift the needle valve 12 is through the actuator 13 generated. In this case, it can thus be determined that the driving force of the actuator 13 is impaired. The actuator 13 will be replaced by a new one.
• (4) When the difference Δtd is smaller than "-Thd" and the difference Δte is smaller than "-The", it can be estimated that a reaction speed of the needle valve 12 is increased to the drive signal. When a foreign object enters the control chamber 15 is introduced and a volume of the control chamber 15 is lowered, a deviation of the speed of the fuel pressure is increased, which is on the needle valve 12 acts. When the volume of the control chamber 15 is lowered and the drive signal is turned ON, is a deviation of the speed of the fuel pressure to a lower value in the back pressure chamber 16 higher. When the drive signal is turned OFF, the deviation of the speed of the fuel pressure is higher to a higher value. In this case, therefore, the kind of abnormality as an existing foreign matter in the control chamber 15 be determined. The control chamber 15 is disassembled to be washed out, leaving a foreign body from the control chamber 15 Will get removed.

According to the above-mentioned first embodiment, the following advantages can be obtained.

The meter 70 may determine, with respect to each of the injection rate parameters "Rmax", "td", "te", whether the fuel injector 10 is abnormal. When it is determined that abnormality in the fuel injector 10 present, the measuring instrument 70 based on the one of the parameters that exceeds the threshold, identify an abnormal section. When the abnormal portion in the fuel injection condition is identified, the meter may 70 the type of fuel injector abnormality 10 determine. Based on the nature of the abnormality, the fuel injector 10 to be repaired.

Second Embodiment

Regarding 5 hereinafter, an abnormality determination test of the fuel injector will be made 10 described according to a second embodiment. The abnormality determination test is performed in a factory before delivery or in a service factory after delivery. In particular, a high pressure pump 71 and a measuring instrument 70 with a fuel injector 10 connected. The fuel injector 10 is arranged such that its pointed end on a vessel 80 with a strain gauge strip 81 is directed.

First, represents the control unit of the meter 70 based on an injection amount Q and a supply pressure Pc on a matching point. The pump 71 leads the fuel with the supply pressure Pc to the fuel inlet 11f of the fuel injector 10 to. The control unit of the measuring instrument 70 transmits a drive signal corresponding to the injection amount Q of the fuel injector 10 corresponds to the fuel injector 10 head for.

The fuel injector 10 injects the fuel through the nozzle mouth 11b into the vessel 80 one. The strain gauge 81 receives a pressure from the injected fuel. The absorbed fuel pressure is converted into an electrical signal and to the measuring instrument 70 transfer. A deviation of the electrical signal sent to the meter 70 is transmitted corresponds to the injection rate waveform (trapezoidal in FIG 3 (b) ). Based on the measured injection rate waveform, the control unit calculates the meter 70 the injection rate parameters "Rmax", "td", "te" which identify the injection rate waveform.

Further, the control unit respectively calculates the differences "ΔRmax", "Δtd", "Δte" between the calculated injection rate parameters "Rmax", "td", "te" and the reference injection rate parameters "Rmaxm", "tdm", "tem". The reference injection rate parameters identify the reference injection rate waveform stored in a memory. The control unit of the measuring instrument 70 determined by comparing the differences "ΔRmax", "Δtd", "Δte" with the threshold values "Thr", "Thd", "The" whether the fuel injector 10 is abnormal. When the control unit determines that there is an abnormality, the control unit determines the type of abnormality based on the parameter exceeding a threshold value.

According to the above-mentioned second embodiment, the following advantages can be obtained.

The injection rate parameters "Rmax", "td", "te" identifying the injection rate waveform (fuel injection condition) are calculated with respect to the adjustment point. Thereafter, the control unit respectively calculates the differences "ΔRmax", "Δtd", "Δte" between the calculated injection rate parameters "Rmax", "td", "te" and the reference injection rate parameters "Rmaxm", "tdm", "tem". Thus, the second embodiment achieves the same advantages as those of the first embodiment.

Other Embodiment

In the second embodiment, the fuel injector includes 10 in it the fuel pressure sensor 20 , However, the fuel pressure sensor is 20 not always required. In a case where the vessel 80 with the strain gauge 81 is provided, the injection rate parameter may be without the fuel pressure sensor 20 be obtained.

Even in the case of the small injection, it can be determined by comparing the injection rate parameters with the respective threshold values whether the fuel injector 10 is abnormal and what kind of abnormality of the fuel injector 10 having. The maximum injection rate Rmax is an injection rate at which the fuel flow through the seating surfaces 11e . 12a is limited. There is a correlation between the maximum injection rate Rmax and a fuel flow channel area between the seating surfaces 11e . 12a , When it is determined that | ΔRmax | > Thr is satisfied, it can be determined that these surfaces 11e . 12a are abnormal. In this case, the seating surfaces 11e . 12a of the fuel injector 10 replaced by new surfaces.

In the first embodiment, the abnormality determination test is performed in a factory before delivery or in a service factory after delivery. However, the abnormality determination test may be performed after delivery while the engine is running.

The actuator 13 may be an electromagnetic actuator. Even in the case where an electromagnetic actuator is used, it can be determined that the driving force of the actuator 13 is impaired when Δtd> Thd and Δtd <"-The".

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 200974536 A [0002]
• EP 2031226 A2 [0002]

Claims (10)

An abnormality determining apparatus applied to a fuel injection system including a fuel injector ( 10 ) passing through a nozzle orifice ( 11b ) Injecting fuel into a machine, the abnormality determination device comprising: a parameter calculation section (10); 70 ) that calculates parameters that identify an injection rate waveform with respect to a matching point, wherein the injection rate waveform represents a deviation of an injection rate of the fuel injected by the fuel injector ( 10 ), and the adjustment point by an injection amount of the fuel and a pressure of the fuel supplied to the fuel injector ( 10 ) is defined; a difference calculation section ( 70 calculating a difference between each of the parameters calculated by the parameter calculating section and a reference parameter identifying a predetermined reference injection rate waveform; and an abnormality determination section that determines, based on the difference calculated by the difference calculation section, with respect to each of the parameters, whether the fuel injector (FIG. 10 ) has an abnormality, wherein: the abnormality determination section defines a kind of the abnormality of the fuel injector ( 10 ) is determined based on the parameter whose value exceeds a threshold value when the abnormality determination section determines that the fuel injector ( 10 ) has the abnormality. An abnormality determining apparatus applied to a fuel injection system including a fuel injector ( 10 ) passing through a nozzle orifice ( 11b ) Injects fuel into an engine, and a fuel pressure sensor ( 20 ), which detects a fuel pressure that the fuel injector ( 10 ), wherein the abnormality determination device comprises: a pressure waveform detection section (10) 70 ) based on a detection value of the fuel pressure sensor ( 20 ) detects a deviation of the fuel pressure as a pressure waveform with respect to a matching point, the adjustment point being determined by an injection amount of the fuel and a pressure of the fuel supplied to the fuel injector ( 10 ) is defined; a parameter calculation section ( 70 ) based on the pressure waveform detected by the pressure waveform detection section (FIG. 70 ), calculates parameters that identify an injection rate waveform with respect to the adaptation point; a difference calculation section ( 70 ) that calculates a difference between the parameter calculated by the parameter calculation section and a parameter that identifies a predetermined reference injection rate waveform; and an abnormality determination section that determines, based on the difference calculated by the difference calculation section, with respect to each of the parameters, whether the fuel injector (FIG. 10 ) has an abnormality, wherein: the abnormality determination section defines a kind of the abnormality of the fuel injector ( 10 ) is determined based on the parameter whose value exceeds a threshold value when the abnormality determination section determines that the fuel injector ( 10 ) has the abnormality. An abnormality determination apparatus according to claim 1 or 2, wherein the parameters include a maximum injection rate. The abnormality determination device according to claim 3, wherein: the abnormality determination section determines that a diameter of the nozzle orifice ( 11b ) is abnormal when a difference between the maximum injection rate of the injection rate waveform and the maximum injection rate of the predetermined reference injection rate waveform is greater than a threshold value. An abnormality determination device according to any one of claims 1 to 4, wherein: the parameters include: an injection start delay time corresponding to a time after a drive signal to the fuel injector ( 10 ) Is ON until the fuel injection is actually started; and an injection end delay time corresponding to a time after the drive signal is turned OFF until the fuel injection is actually stopped. An abnormality determination device according to claim 5, wherein: the fuel injector ( 10 ) is equipped with: a drive section ( 13 ) which generates a drive force when receiving the drive signal; and a tip sliding section ( 12 ), the nozzle orifice ( 11b ) opens by the driving force; wherein the abnormality determination section determines that a foreign matter is around the tip sliding section (10) 12 ) when a high-degree difference from the injection start delay time of the injection rate waveform exceeds a threshold value relative to the injection start delay time of the reference injection rate waveform, and when a large degree difference from the injection end delay time of the injection rate waveform exceeds the injection end delay time of the reference injection rate waveform exceeds a threshold value. An abnormality determination device according to claim 5, wherein: the fuel injector ( 10 ) is equipped with: a drive section ( 13 ) which generates a driving force when receiving the driving signal; and a tip sliding section ( 12 ), the nozzle orifice ( 11b ) opens by the driving force; wherein the abnormality determination section determines that a foreign matter is around the tip sliding section (10) 12 ) when a large-degree difference from the injection start delay time of the injection rate waveform exceeds a threshold value in relation to the injection start delay time of the reference injection rate waveform, and when a small-degree difference from the injection end delay time of the injection rate waveform exceeds the injection end delay time of the reference injection rate waveform exceeds a threshold value. An abnormality determination device according to claim 5, wherein: the fuel injector ( 10 ) is equipped with: a drive section ( 13 ) which generates a driving force when receiving the driving signal; a point sliding section ( 12 ), which by a fuel pressure, which is applied to this, the nozzle orifice ( 11b ) opens; and a control chamber ( 15 ) for controlling the fuel pressure generated by the driving force supplied by the driving section ( 13 ) is generated on the tip sliding portion ( 12 ) is applied; and the abnormality determination section determines that a foreign substance is present in the control chamber ( 15 ) when a small-order difference from the injection start delay time of the injection rate waveform exceeds a threshold value relative to the injection start delay time of the reference injection rate waveform, and a small-order difference from the injection end delay time of the injection rate waveform exceeds the injection end delay time of the reference injection rate waveform exceeds a threshold value. Anomaly determination method of a fuel injector ( 10 ) passing through a nozzle orifice ( 11b ) Injecting fuel into an engine, the abnormality determination method comprising: calculating a parameter identifying an injection rate waveform with respect to a matching point, the injection rate waveform representing a deviation of an injection rate of the fuel injected by the fuel injector ( 10 ), and the adjustment point by an injection amount of the fuel and a pressure of the fuel supplied to the fuel injector ( 10 ) is defined; a calculation of a difference between the parameter calculated by calculating the parameter and a parameter identifying a predetermined reference injection rate waveform; and a determination with respect to each of the parameters whether the fuel injector ( 10 ) has an abnormality based on the difference calculated by calculating the difference, wherein: a type of abnormality of the fuel injector ( 10 ) is determined based on the parameter whose value exceeds a threshold value when it is determined that the fuel injector ( 10 ) has the abnormality. Anomaly determination method of a fuel injection system including a fuel injector ( 10 ) passing through a nozzle orifice ( 11b ) Injects fuel into an engine, and a fuel pressure sensor ( 20 ), which detects a fuel pressure that the fuel injector ( 10 ), wherein the abnormality determination method comprises: detecting a deviation of the fuel pressure as a pressure waveform based on a detection value of the fuel pressure sensor ( 20 ) with respect to an adjustment point, wherein the adaptation point is determined by an injection amount of the fuel and a pressure of the fuel flowing to the fuel injector ( 10 ) is defined; a calculation of parameters that identify an injection rate waveform with respect to the fitting point based on the pressure waveform detected by detecting the deviation; a calculation of a difference between the parameter calculated by calculating the parameter and a parameter identifying a predetermined reference injection rate waveform; and a determination with respect to each of the parameters whether the fuel injector ( 10 ) has an abnormality based on the difference calculated by calculating the difference, wherein: a type of abnormality of the fuel injector ( 10 ) is determined based on the parameter whose value exceeds a threshold value when it is determined that the fuel injector ( 10 ) has the abnormality.

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