JP5375848B2 - Fuel injection condition analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection condition analyzing device to improve the arithmetic processing efficiency for the analysis of an injection condition. <P>SOLUTION: The fuel injection condition analyzing device is applied to a fuel injection system provided with: a fuel injection valve 10 for injecting the fuel having a pressure accumulated by a common rail (accumulation container); and a fuel pressure sensor 20 arranged in a fuel passage from a discharge port of the common rail up to an injection hole of the fuel injection valve and detecting the fuel pressure. Also, the fuel injection condition analyzing device includes an injection rate parameter calculation means 31 (analysis means) for analyzing the fuel injection condition based on the variation of the detected value of the fuel pressure sensor 20 accompanying the fuel injection. In the fuel injection condition analyzing device, the analysis by the injection rate parameter calculation means 31 is intermittently executed without continuously executing for each injection when the fuel is sequentially injected from the fuel injection valve 10 of each cylinder. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an apparatus for analyzing a fuel injection state from a fuel injection valve provided in an internal combustion engine.

  In Patent Literatures 1 to 3 and the like, a fuel pressure sensor detects a pressure of fuel supplied to a fuel injection valve to detect a change in the pressure of the supplied fuel caused by the fuel injection. An invention for analyzing an injection state is disclosed. For example, since the pressure drop start time and the injection start time that occur as a result of the start of injection are highly correlated, the injection start time (injection state) can be calculated (analyzed) by detecting the pressure drop start time. Then, by performing feedback control of the operation of the fuel injection valve based on the injection state calculated in this way, the injection control can be performed with high accuracy so that the injection state becomes a desired state.

JP 2009-103063 A JP 2010-3004 A JP 2010-223184 A

  However, in order to analyze the injection state from the detection value of the fuel pressure sensor, a large calculation load is applied to the arithmetic device (fuel injection state analyzing device) composed of a CPU, a memory, etc. An arithmetic unit having a large storage capacity is required. For this reason, the cost increase of the said apparatus becomes a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fuel injection state analysis apparatus that improves the efficiency of arithmetic processing for analyzing the injection state.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

According to the first aspect of the present invention, a fuel injection valve that is provided in each cylinder of the multi-cylinder internal combustion engine and injects fuel accumulated in the pressure accumulating vessel, and from the discharge port of the pressure accumulating vessel to the nozzle hole of the fuel injection valve It is assumed that the present invention is applied to a fuel injection system that includes a fuel pressure sensor that is disposed in the fuel passage and detects a fuel pressure in the fuel passage. An analysis means for analyzing the fuel injection state based on a change in the detected value of the fuel pressure sensor caused by fuel injection is provided, and fuel is sequentially injected from the fuel injection valve of each cylinder. The analysis by the analysis means is performed in the order obtained by jumping a predetermined number of jumps, and the order of the fuel injection valves to be analyzed among the fuel injection valves of each cylinder is accumulated in the analysis for each fuel injection valve. It is characterized by being set so as to circulate so that the number of times becomes the same .

  Here, contrary to the above-described invention, if the analysis by the analysis means is continuously performed for each injection, the analysis must be completed in an extremely short time such as an injection cycle, and the fuel injection state analysis device requires a large amount of computation. Load is applied. On the other hand, in the said invention, the analysis by an analysis means is implemented in the order obtained by jumping a predetermined jump number with respect to the injection order. In other words, rather than analyzing the fuel injection of all the injection cylinders in the order of fuel injection of each cylinder (for example, # 1 → # 3 → # 4 → # 2 → # 1 in the case of a four-cylinder engine), it is intermittent. Analyzes will be performed. Thereby, compared with the case where it analyzes with respect to all the injections, the efficiency of arithmetic processing can be achieved.

Furthermore , since the fuel injection valves of each cylinder can be analyzed uniformly, the injection control accuracy of each cylinder can be made uniform, and as a result, the controllability of the operating state (engine output, exhaust emission, etc.) of the internal combustion engine can be improved.

The invention according to claim 2 is characterized in that the number of jumps is set to one less than the number of cylinders.

  According to this, when jumping so that the number of times of analysis is the same, it is possible to repeatedly jump with the same number of jumps. Therefore, the arithmetic program can be simplified as compared with the case where the jump number is sequentially changed.

  Specifically, for example, in the case of a four-cylinder internal combustion engine, the number of jumps is set to three. Then, when fuel is injected in the order of # 1 → # 3 → # 4 → # 2, after analyzing # 1, jump to # 2 by skipping # 3 # 4 and analyze # 2 . That is, the analysis is performed by circulating in the order of # 1 → # 2 → # 4 → # 3 → # 1 →... (See FIG. 7A).

  Similarly, in the case of a 6-cylinder internal combustion engine, for example, when the number of jumps is set to 5 and fuel is injected in the order of # 1 → # 5 → # 3 → # 6 → # 2 → # 4, The analysis is repeated in the order of 1 → # 4 → # 2 → # 6 → # 3 → # 5 → # 1 →... (See FIG. 8A).

In the invention of claim 3, the number of jumps is repeatedly set alternately between the first jump number and the second jump number, the first jump number is set to half the number of cylinders, and the second jump number is The number of cylinders is set to be one less than half of the number of cylinders, one more than half of the number of cylinders, and two or more.

  According to this, when jumping so that the number of times of analysis is the same, it is possible to repeatedly jump alternately with the first jump number and the second jump number. Therefore, the arithmetic program can be simplified as compared with the case where two or more types of jump numbers are set and the jump numbers are sequentially changed.

Further, as compared with the case of repeatedly jumping with the same number of jumps as in the second aspect of the invention, the number of analyzes can be increased (the number of intermittent skipping is reduced). The control accuracy can be improved.

  Specifically, for example, in the case of a four-cylinder internal combustion engine, the first jump number is set to 2 and the second jump number is set to 3. Then, when injecting fuel in the order of # 1 → # 3 → # 4 → # 2, after analyzing # 1, skip # 3, jump to # 4, analyze # 4, and then Skip # 2 # 1 and jump to # 3 to analyze # 3. That is, (# 1 → # 4 → # 3 → # 2) → (# 4 → # 1 → # 2 → # 3) → (# 1 → # 4 → # 3 → # 2) →... Thus, the analysis is performed (see FIG. 9A).

  Similarly, for example, in the case of a 6-cylinder internal combustion engine, the first jump number is set to 3 and the second jump number is set to 4, and the fuel is in the order of # 1 → # 5 → # 3 → # 6 → # 2 → # 4. (# 1 → # 6 → # 5 → # 2 → # 3 → # 4) → (# 6 → # 1 → # 2 → # 5 → # 4 → # 3) → (# 1 → # 6 → # 5 → # 2 → # 3 → # 4) →... Circulate and analyze in this order (see FIG. 10A).

The invention according to claim 4 is characterized in that the jump number is set larger as the rotational speed of the output shaft of the internal combustion engine is higher.

  The faster the rotation speed of the output shaft, the shorter the injection interval when fuel is sequentially injected from the fuel injection valve of each cylinder, so the time that can be spent for analysis becomes shorter. In view of this point, since the number of jumps is set to be larger as the rotational speed of the output shaft is higher in the above invention, it is possible to suppress the time that can be spent for analysis from being shortened. In other words, fluctuations in the time that can be spent for analysis can be suppressed. Therefore, necessary analysis time can be secured.

According to a fifth aspect of the present invention, when the cylinder that is injecting fuel is an injection cylinder, and the cylinder that is stopped when the fuel is injected by the injection cylinder is a back cylinder, the analysis means includes the injection cylinder An injection waveform generating means for generating an injection waveform representing a change in a detected value by the fuel pressure sensor at the back, a back waveform generating means for generating a back waveform representing a change in the detected value by the fuel pressure sensor at the back cylinder, and Calculation means for calculating an injection state in the injection cylinder based on a waveform obtained by subtracting the back waveform from an injection waveform, and injecting fuel sequentially from the fuel injection valve of each cylinder. The generation by the injection waveform generation means and the generation by the back waveform generation means are performed in an order obtained by jumping a predetermined number of jumps relative to the order.

  Here, when the detection timing by the fuel pressure sensor and the timing for pumping the fuel to the pressure accumulating vessel overlap, the back waveform shows a waveform component representing the pressure drop that occurs according to the fuel injection amount in the injection cylinder (Decrease component) and a waveform component (pumping component) representing an increase in pressure in the pressure accumulating vessel due to pumping are superimposed. Moreover, in addition to the said fall component and the said pumping component, the component (injection component) of the injection waveform showing the fuel pressure change resulting from injection will be superimposed on the injection waveform. Therefore, the injection component can be extracted by subtracting the back waveform from the injection waveform, and the analysis accuracy by the analysis means can be improved based on the extracted injection component.

  According to the above invention in view of this point, since the injection state in the injection cylinder is calculated based on the waveform obtained by subtracting the back waveform from the injection waveform, the injection state can be calculated with high accuracy. In addition, since the generation by the injection waveform generation means and the generation by the back waveform generation means are intermittently performed without continuously performing each injection, the generation processing is performed in the same manner as in each of the above-described inventions. The required processing capacity can be reduced.

It is a figure showing an outline of a fuel injection system to which a fuel injection state analysis device concerning a 1st embodiment of the present invention is applied. It is a figure which shows the change of the injection rate and fuel pressure corresponding to an injection command signal. In 1st Embodiment, it is a block diagram which shows the outline | summarys, such as a setting of the injection command signal with respect to a fuel injection valve. 4 is a flowchart illustrating a procedure for calculating an injection rate parameter in the first embodiment. It is a flowchart which shows the subroutine process of FIG. It is a figure which shows the injection waveform Wa, the back waveform Wu, and the injection component Wb. It is a figure explaining the order of the cylinder which performs the analysis process of FIG. FIG. 5 is a diagram illustrating the order of cylinders that perform the analysis processing of FIG. 4 in the second embodiment of the present invention. In 3rd Embodiment of this invention, it is a figure explaining the order of the cylinder which implements the analysis process of FIG. In 4th Embodiment of this invention, it is a figure explaining the order of the cylinder which performs the analysis process of FIG.

  Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. Note that the fuel injection state estimation device described below is mounted on a vehicle engine (internal combustion engine). The engine injects high-pressure fuel into a plurality of cylinders and performs compression self-ignition combustion. A cylinder diesel engine is assumed.

(First embodiment)
FIG. 1 is a schematic diagram showing a fuel injection valve 10 mounted on each cylinder of the engine, a fuel pressure sensor 20 mounted on each fuel injection valve 10, an ECU 30 that is an electronic control device mounted on a vehicle, and the like. is there.

  First, an engine fuel injection system including the fuel injection valve 10 will be described. The fuel in the fuel tank 40 is pumped and stored in the common rail 42 (pressure accumulating container) by the fuel pump 41, and distributed and supplied to the fuel injection valves 10 (# 1 to # 4) of each cylinder. The plurality of fuel injection valves 10 (# 1 to # 4) sequentially inject fuel in a preset order. In this embodiment, it is assumed that injection is performed in the order of # 1 → # 3 → # 4 → # 2.

  In addition, since the plunger pump is used for the fuel pump 41, fuel is pumped in synchronism with the reciprocating motion of the plunger. Since the fuel pump 41 is driven by the crankshaft using the engine output as a driving source, the fuel is pumped from the fuel pump 41 a predetermined number of times during one combustion cycle.

  The fuel injection valve 10 includes a body 11, a needle-shaped valve body 12, an actuator 13, and the like described below. The body 11 forms a high-pressure passage 11a inside and a nozzle hole 11b for injecting fuel. The valve body 12 is accommodated in the body 11 and opens and closes the nozzle hole 11b.

  A back pressure chamber 11c for applying a back pressure to the valve body 12 is formed in the body 11, and the high pressure passage 11a and the low pressure passage 11d are connected to the back pressure chamber 11c. The communication state between the high pressure passage 11a and the low pressure passage 11d and the back pressure chamber 11c is switched by the control valve 14, and the actuator 13 such as an electromagnetic coil or a piezoelectric element is energized to push the control valve 14 downward in FIG. As a result, the back pressure chamber 11c communicates with the low pressure passage 11d and the fuel pressure in the back pressure chamber 11c decreases. As a result, the back pressure applied to the valve body 12 is lowered and the valve body 12 is lifted up (opening operation). Thereby, the seat surface 12a of the valve body 12 is separated from the seat surface 11e of the body 11, and fuel is injected from the injection hole 11b.

  On the other hand, when the power supply to the actuator 13 is turned off and the control valve 14 is operated upward in FIG. 1, the back pressure chamber 11c communicates with the high pressure passage 11a and the fuel pressure in the back pressure chamber 11c increases. As a result, the back pressure applied to the valve body 12 increases and the valve body 12 is lifted down (closed valve operation). Thereby, the seat surface 12a of the valve body 12 is seated on the seat surface 11e of the body 11, and the fuel injection from the injection hole 11b is stopped.

  Therefore, the ECU 30 controls the energization of the actuator 13 so that the opening / closing operation of the valve body 12 is controlled. Thereby, the high-pressure fuel supplied from the common rail 42 to the high-pressure passage 11 a is injected from the injection hole 11 b according to the opening / closing operation of the valve body 12.

  The fuel pressure sensor 20 is mounted on all the fuel injection valves 10 and includes a stem 21 (a strain generating body) and a pressure sensor element 22 described below. The stem 21 is attached to the body 11, and the diaphragm portion 21a formed on the stem 21 is elastically deformed by receiving the pressure of the high-pressure fuel flowing through the high-pressure passage 11a. The pressure sensor element 22 is attached to the diaphragm portion 21a, and outputs a pressure detection signal to the ECU 30 in accordance with the amount of elastic deformation generated in the diaphragm portion 21a.

  The ECU 30 includes a CPU 34a and a microcomputer (microcomputer 34) having a memory 34b such as a RAM and a ROM. The microcomputer 34 has a target injection state based on the operation amount of the accelerator pedal, the engine load, the engine rotational speed NE, and the like. (For example, the number of injection stages, the injection start timing, the injection end timing, the injection amount, etc.) are calculated. For example, the optimal injection state corresponding to the engine load and the engine speed is stored as an injection state map. Based on the current engine load and engine speed, the target injection state is calculated with reference to the injection state map. Then, the injection command signals t1, t2, and Tq (see FIG. 2A) corresponding to the calculated target injection state are set based on the injection rate parameters td, te, Rα, Rβ, and Rmax described in detail later, and the fuel By outputting to the injection valve 10, the operation of the fuel injection valve 10 is controlled.

  Next, a method of injection control when fuel is injected from the fuel injection valve 10 will be described below with reference to FIGS.

  A change in fuel pressure caused by injection is detected as a fuel pressure waveform (see FIG. 2C) based on the detection value of the fuel pressure sensor 20, and an injection rate waveform representing a change in fuel injection rate based on the detected fuel pressure waveform. (See FIG. 2B) is calculated to detect the injection state. Then, while learning the injection rate parameters Rα, Rβ, and Rmax that specify the detected injection rate waveform (injection state), the correlation between the injection command signals (pulse-on timing t1, pulse-off timing t2, and pulse-on period Tq) and the injection state. The injection rate parameters td and te for specifying

  Specifically, in the fuel pressure waveform, a descending approximation line that approximates a descending waveform from the inflection point P1 at which the fuel pressure drop starts at the start of injection to the inflection point P2 at which the descent ends by a least square method or the like. Lα is calculated. Then, a time (a crossing time LBα between Lα and Bα) that is the reference value Bα in the descending approximate straight line Lα is calculated. Focusing on the fact that the intersection time LBα and the injection start time R1 are highly correlated, the injection start time R1 is calculated based on the intersection time LBα. For example, a timing that is a predetermined delay time Cα before the intersection timing LBα may be calculated as the injection start timing R1.

  In addition, a rising approximation line Lβ is calculated by approximating the rising waveform from the inflection point P3 where the fuel pressure rises at the end of injection to the inflection point P5 where the descent ends from the fuel pressure waveform by a least square method or the like. To do. Then, a time (intersection time LBβ between Lβ and Bβ) that is the reference value Bβ in the rising approximate straight line Lβ is calculated. Focusing on the fact that the intersection timing LBβ and the injection end timing R4 are highly correlated, the injection end timing R4 is calculated based on the intersection timing LBβ. For example, a timing that is a predetermined delay time Cβ before the intersection timing LBβ may be calculated as the injection end timing R4.

  Next, paying attention to the fact that the slope of the descending approximate line Lα and the slope of the injection rate increase are highly correlated, the slope of the straight line Rα indicating the increase in the injection rate waveform shown in FIG. Calculation is based on the slope of Lα. For example, the slope of Rα may be calculated by multiplying the slope of Lα by a predetermined coefficient. Similarly, since the slope of the rising approximate line Lβ and the slope of the injection rate decrease are highly correlated, the slope of the straight line Rβ indicating the decrease in injection in the injection rate waveform is calculated based on the slope of the rising approximate line Lβ.

  Next, based on the straight lines Rα and Rβ of the injection rate waveform, a timing (valve closing operation start timing R23) at which the valve body 12 starts lift-down in response to the command to end injection is calculated. Specifically, the intersection of both straight lines Rα and Rβ is calculated, and the intersection timing is calculated as the valve closing operation start timing R23. Further, a delay time (injection start delay time td) with respect to the injection start command timing t1 of the injection start timing R1 is calculated. Further, a delay time (injection end delay time te) with respect to the injection end command timing t2 of the valve closing operation start timing R23 is calculated.

  Further, the pressure corresponding to the intersection of the descending approximate straight line Lα and the ascending approximate straight line Lβ is calculated as the intersection pressure Pαβ, and a pressure difference ΔPγ between the reference pressure Pbase and the intersection pressure Pαβ, which will be described in detail later, is calculated. Focusing on the fact that the correlation with the maximum injection rate Rmax is high, the maximum injection rate Rmax is calculated based on the pressure difference ΔPγ. Specifically, the maximum injection rate Rmax is calculated by multiplying the pressure difference ΔPγ by the correlation coefficient Cγ. However, in the case of the small injection in which the pressure difference ΔPγ is less than the predetermined value ΔPγth, Rmax = ΔPγ × Cγ is set as described above, while in the case of the large injection in which ΔPγ ≧ ΔPγth, it is set in advance. The value (set value Rγ) is calculated as the maximum injection rate Rmax.

  Note that the “small injection” is assumed to be an injection in which the valve body 12 starts to be lifted down before the injection rate reaches Rγ, and the fuel is throttled at the seat surfaces 11e and 12a to thereby reduce the injection amount. The injection rate when it is restricted becomes the maximum injection rate Rmax. On the other hand, the “large injection” is assumed to be an injection in which the valve body 12 starts to lift down after the injection rate reaches Rγ, and the injection amount is limited by the fuel being throttled at the injection hole 11b. The injection rate when the engine is running is the maximum injection rate Rmax. In short, when the injection command period Tq is sufficiently long and the valve opening state is continued even after reaching the maximum injection rate, the injection rate waveform shown in FIG. On the other hand, in the case of small injection that starts the valve closing operation before reaching the maximum injection rate, the injection rate waveform is a triangle.

  The set value Rγ which is the maximum injection rate Rmax at the time of large injection changes as the fuel injection valve 10 changes over time. For example, when aged deterioration such as deposits or the like deposits on the nozzle holes 11b and the injection amount decreases, the pressure drop amount ΔP shown in FIG. 2C decreases. Further, as the seat surface 11e, 12a wears and the aging deterioration such that the injection amount increases, the pressure drop amount ΔP increases. Note that the pressure drop amount ΔP is the amount of decrease in the detected pressure caused by the increase in the injection rate. For example, the pressure drop amount from the reference pressure Pbase to the inflection point P2 or the change from the inflection point P1. It is the amount of pressure drop to the bend point P2.

  Therefore, in the present embodiment, focusing on the fact that the maximum injection rate Rmax (set value Rγ) and the pressure drop amount ΔP during large injection are highly correlated, learning is performed by calculating the set value Rγ from the detection result of the pressure drop amount ΔP. To do. That is, the learned value of the maximum injection rate Rmax at the time of large injection corresponds to the learned value of the set value Rγ based on the pressure drop amount ΔP.

  As described above, the injection rate parameters td, te, Rα, Rβ, and Rmax can be calculated from the fuel pressure waveform. Based on the learned values of the injection rate parameters td, te, Rα, Rβ, and Rmax, an injection rate waveform (see FIG. 2B) corresponding to the injection command signal (see FIG. 2A) is calculated. be able to. Since the area of the injection rate waveform calculated in this way (see halftone dot hatching in FIG. 2B) corresponds to the injection amount, the injection amount can also be calculated based on the injection rate parameter.

  FIG. 3 is a block diagram showing an outline of learning of these injection rate parameters, setting of an injection command signal to be output to the fuel injection valve 10, and the like, and each means 31, 32, 33 functioning by the microcomputer 34 of the ECU 30 will be described below. Explained. The injection rate parameter calculation means 31 (analysis means) calculates injection rate parameters td, te, Rα, Rβ, Rmax based on the fuel pressure waveform detected by the fuel pressure sensor 20.

  The learning means 32 learns by updating the calculated injection rate parameter in the memory 34b of the ECU 30. Since the injection rate parameter varies depending on the supply fuel pressure (pressure in the common rail 42) at that time, the injection rate parameter can be learned in association with the supply fuel pressure or a reference pressure Pbase (see FIG. 2C) described later. desirable. In the example of FIG. 3, the injection rate parameter value corresponding to the fuel pressure is stored in the injection rate parameter map M.

  The setting means 33 (control means) acquires the injection rate parameter (learned value) corresponding to the current fuel pressure from the injection rate parameter map M. And based on the acquired injection rate parameter, the injection command signals t1, t2, and Tq corresponding to the target injection state are set. The fuel pressure sensor 20 detects the fuel pressure waveform when the fuel injection valve 10 is operated in accordance with the injection command signal set in this way, and the injection rate parameter calculation means 31 based on the detected fuel pressure waveform, the injection rate parameter td, te, Rα, Rβ, Rmax are calculated.

  In short, an actual injection state (that is, injection rate parameters td, te, Rα, Rβ, Rmax) with respect to the injection command signal is detected and learned, and an injection command signal corresponding to the target injection state is set based on the learned value. . Therefore, the injection command signal is feedback-controlled based on the actual injection state, and the fuel injection state can be controlled with high accuracy so that the actual injection state coincides with the target injection state even when the above-described aging deterioration proceeds.

  In particular, feedback control is performed so as to set the injection command period Tq based on the injection rate parameter so that the actual injection amount becomes the target injection amount, so that the actual injection amount is compensated to become the target injection amount.

  Next, the procedure for analyzing the injection state by calculating the injection rate parameters td, te, Rα, Rβ, Rmax (see FIG. 2B) from the detected fuel pressure waveform (see FIG. 2C) is shown in FIG. This will be described with reference to the flowchart of FIG. Note that the process shown in FIG. 4 is repeatedly executed by the microcomputer 34 included in the ECU 30.

  First, in step S5 shown in FIG. 4, it is determined whether or not fuel injection has been performed in the cylinders in the analysis order set in advance. This analysis order will be described later in detail with reference to FIG.

  If it is determined that the injection is performed in the analysis order cylinder (S5: YES), the injection component Wb used for the analysis of the injection state is calculated based on the detection value of the fuel pressure sensor 20 in the subsequent step S10.

  FIG. 5 is a flowchart showing the subroutine processing in step S10. In the following description, a cylinder during fuel injection is called an injection cylinder, and a cylinder that stops injection when fuel is injected in the injection cylinder is called a back cylinder. The fuel pressure sensor 20 mounted on the fuel injection valve 10 of the injection cylinder is referred to as an injection time sensor, and the fuel pressure sensor 20 mounted on the fuel injection valve 10 of the back cylinder is referred to as a non-injection sensor.

  First, in step S10a of FIG. 5, a plurality of detection values detected at a predetermined sampling period are acquired by an injection time sensor, and an injection that represents a change in fuel pressure at the injection time sensor caused by the injection based on these detection values. A waveform Wa (see FIG. 6A) is generated. Note that high-frequency noise is removed from the generated ejection waveform Wa using means such as a low-pass filter.

  In subsequent step S10b, a plurality of detection values detected at a predetermined sampling period by the non-injection sensor are acquired, and a back waveform Wu representing a change in fuel pressure at the non-injection sensor caused by injection is obtained based on these detection values. (See FIG. 6B). Note that high-frequency noise is removed from the generated back waveform Wu using means such as a low-pass filter.

  Incidentally, when the fuel pump 41 and the common rail 42 are fed with fuel at the same timing and injection timing, the back waveform Wu is a waveform in which the pressure is generally increased as shown by the solid line in FIG. 6B. It becomes. On the other hand, when such pump pumping is not performed during fuel injection, immediately after the fuel is injected, the fuel pressure in the entire injection system is reduced by that amount. Therefore, the back waveform Wu ′ is a waveform in which the pressure is reduced as a whole, as indicated by the dotted line in FIG.

  Such components of the back waveforms Wu and Wu 'are also included in the injection waveform Wa generated in step S10a. In other words, it can be said that the injection waveform Wa includes an injection component Wb representing a change in fuel pressure due to injection and components of the back waveforms Wu and Wu ′.

  Therefore, in the next step S10c, the injection component Wb is extracted by subtracting the back waveforms Wu, Wu ′ generated in step S10b from the injection waveform Wa generated in step S10a (Wb = Wa−Wu). .

  Here, when performing multi-stage injection, the swell component Wc (see FIG. 2C), which is the pulsation after injection of the fuel pressure waveform for the pre-stage injection, is superimposed on the injection waveform Wa generated in step S10a. In particular, when the interval from the preceding injection is short, the injection waveform Wa is greatly affected by the swell component Wc. Therefore, when multi-stage injection is being performed (S10d: YES), the process proceeds to the next step S10e, and swell removal processing for subtracting the swell component Wc of the previous stage injection from the injection component Wb is performed.

  As described above, by executing the subroutine processing of FIG. 5, the injection component Wb used for calculating the injection rate parameters td, te, Rα, Rβ, and Rmax (injection state analysis) is calculated.

  Returning to the description of FIG. 4, after calculating the injection component Wb in step S <b> 10, in the subsequent step S <b> 11, in the waveform of the portion corresponding to the period until the fuel pressure starts to decrease with the start of injection in the injection component Wb. Based on a certain reference waveform, the average fuel pressure of the reference waveform is calculated as the reference pressure Pbase. For example, a portion corresponding to a period TA until a predetermined time elapses from the injection start command timing t1 may be set as the reference waveform. Alternatively, the inflection point P1 may be calculated based on the differential value of the descending waveform, and a portion corresponding to a period from the injection start command timing t1 to a predetermined time before the inflection point P1 may be set as the reference waveform.

  In the subsequent step S12 (linear approximation means), an approximate straight line Lα of the descending waveform is calculated based on the descending waveform that is the waveform corresponding to the period during which the fuel pressure decreases as the injection rate increases in the injection component Wb. To do. For example, what is necessary is just to set the part corresponding to predetermined period TB from the time of predetermined time having passed since injection start instruction | command time t1 as a fall waveform. Alternatively, the inflection points P1 and P2 may be calculated based on the differential value of the descending waveform, and the portion corresponding to the inflection points P1 and P2 may be set as the descending waveform. Then, an approximate straight line Lα may be calculated by a least square method from a plurality of detected fuel pressure values (sampling values) constituting the descending waveform. Alternatively, the tangent line at the time when the differential value becomes the minimum in the descending waveform may be calculated as the approximate straight line Lα.

  In the subsequent step S13 (linear approximation means), an approximate straight line Lβ of the rising waveform is calculated based on the rising waveform that is the waveform corresponding to the period during which the fuel pressure increases as the injection rate decreases in the injection component Wb. To do. For example, what is necessary is just to set the part corresponding to the predetermined period TC from the time of predetermined time having passed since the injection end instruction | command time t2 as a rising waveform. Alternatively, the inflection points P3 and P5 may be calculated based on the differential value of the rising waveform, and a portion corresponding to the inflection points P3 and P5 may be set as the rising waveform. Then, the approximate straight line Lβ may be calculated from the plurality of detected fuel pressure values (sampling values) constituting the rising waveform by the least square method. Alternatively, the tangent at the time when the differential value becomes the maximum in the rising waveform may be calculated as the approximate straight line Lβ.

  In subsequent step S14, reference values Bα and Bβ are calculated based on the reference pressure Pbase. For example, values lower than the reference pressure Pbase by a predetermined amount may be calculated as the reference values Bα and Bβ. It is not necessary to set both reference values Bα and Bβ to the same value. The predetermined amount may be variably set according to the value of the reference pressure Pbase, the fuel temperature, and the like.

  In the subsequent step S15, a time (intersection time LBα between Lα and Bα) at which the approximate value Lα becomes the reference value Bα is calculated. Focusing on the fact that the intersection time LBα and the injection start time R1 are highly correlated, the injection start time R1 is calculated based on the intersection time LBα. For example, a timing that is a predetermined delay time Cα before the intersection timing LBα may be calculated as the injection start timing R1.

  In the subsequent step S16, a time (intersection time LBβ between Lβ and Bβ) that is the reference value Bβ in the approximate straight line Lβ is calculated. Focusing on the fact that the intersection timing LBβ and the injection end timing R4 are highly correlated, the injection end timing R4 is calculated based on the intersection timing LBβ. For example, a timing that is a predetermined delay time Cβ before the intersection timing LBβ may be calculated as the injection end timing R4. The delay times Cα and Cβ may be variably set according to the value of the reference pressure Pbase, the fuel temperature, and the like.

  In subsequent step S17, focusing on the fact that the slope of the approximate line Lα and the slope of the injection rate increase are highly correlated, the slope of the straight line Rα indicating the increase in injection in the injection rate waveform shown in FIG. Calculation is based on the slope of Lα. For example, the slope of Rα may be calculated by multiplying the slope of Lα by a predetermined coefficient. Note that, based on the injection start timing R1 calculated in step S15 and the slope of Rα calculated in step S17, a straight line Rα representing the rising portion of the injection rate waveform with respect to the injection command signal can be specified.

  Further, in step S17, paying attention to the fact that the slope of the approximate straight line Lβ and the slope of the injection rate decrease are highly correlated, the slope of the straight line Rβ indicating the decrease in the injection rate waveform is calculated based on the slope of the approximate straight line Lβ. . For example, the slope of Rβ may be calculated by multiplying the slope of Lβ by a predetermined coefficient. Note that, based on the injection end timing R4 calculated in step S16 and the slope of Rβ calculated in step S17, a straight line Rβ representing the descending portion of the injection rate waveform with respect to the injection command signal can be specified. The predetermined coefficient may be variably set according to the value of the reference pressure Pbase, the fuel temperature, and the like.

  In the subsequent step S18, based on the injection rate waveform straight lines Rα and Rβ calculated in step S17, a timing (valve closing operation start timing R23) at which the valve body 12 starts lift-down in response to the command to end the injection is calculated. . Specifically, the intersection of both straight lines Rα and Rβ is calculated, and the intersection timing is calculated as the valve closing operation start timing R23.

  In the subsequent step S19, a delay time (injection start delay time td) of the injection start timing R1 calculated in step S15 with respect to the injection start command timing t1 is calculated. Further, a delay time (injection end delay time te) with respect to the injection end command timing t2 of the valve closing operation start timing R23 calculated in step S18 is calculated. The injection end delay time te is a delay time from the timing t2 at which the injection end is commanded to the timing at which the operation of the control valve 14 is started. In short, these delay times td and te are parameters representing the response delay of the injection rate change with respect to the injection command signal. Besides, the delay time from the injection start command timing t1 to the maximum injection rate arrival timing R2, the injection end command Examples include a delay time from the timing t2 to the injection rate decrease start R3, a delay time from the injection end command timing t2 to the injection end timing R4, and the like.

  In the subsequent step S20, it is determined whether or not the pressure difference ΔPγ between the reference pressure Pbase and the intersection pressure Pαβ is less than a predetermined value ΔPγth. When it is determined that ΔPγ <ΔPγth (S20: YES), in the next step S21 (maximum injection rate calculation means), it is considered that the small injection is described above, and the maximum injection rate Rmax is calculated based on the pressure difference ΔPγ. (Rmax = ΔPγ × Cγ). On the other hand, when it is determined that ΔPγ ≧ ΔPγth (S20: NO), a preset value (set value Rγ) is calculated as the maximum injection rate Rmax in the next step S22 (maximum injection rate calculation means). To do.

  4 corresponds to the “analyzing unit”, and in particular, the microcomputer 34 when executing the processing of steps S11 to S22 is “calculating unit”. Is equivalent to.

  Next, the “analysis order” used in the determination in step S5 in FIG. 4 will be described with reference to FIG.

  The numbers in FIG. 7A indicate the order of the cylinder numbers of the injection cylinders, and indicate that the injection is performed in the order of # 1 → # 3 → # 4 → # 2 → # 1 →. . The numbers with halftone dots in FIG. 7A indicate the cylinder numbers of the fuel injection valves 10 to be analyzed for the injection state by the processing of FIG. 4, and # 1 → # 2 → # 4. Indicates that analysis is performed in the order of # 3 → # 1 →. That is, after analyzing the injection state for # 1, the analysis according to FIG. 4 is not performed for the injection states in # 3 and # 4, and then the injection state is analyzed for # 2.

  In short, in the example of FIG. 7A, the analysis according to FIG. 4 is intermittently performed without continuously performing every injection, and the order in which the injection order is skipped by a predetermined number of jumps m is the analysis order. It is said. The jump number m is set to be one less than the cylinder number n (m = n−1). According to this, since the order of the fuel injection valves 10 to be analyzed circulates evenly, the cumulative number of analyzes performed on each fuel injection valve 10 in the predetermined period is the same.

  The numbers with halftone dots in FIG. 7B indicate the cylinder numbers of the back cylinders used for obtaining the back waveforms Wu, Wu ′, and # 3 → # 1 → # 2 → # 4 → # 3 → In this order, the back waveforms Wu and Wu ′ are generated in step S10b of FIG. In short, in the example of FIG. 7B, the generation of the back waveforms Wu and Wu ′ according to FIG. 5 is performed intermittently without continuously performing every injection, and the injection order is set to a predetermined number of jumps m. The order of skipping is used as the generation order. The jump number m is set to be the same as the jump number according to FIG. 7A (m = n−1).

  As described above, according to the present embodiment, the analysis process according to FIG. 4 is intermittently performed without continuously performing each injection, and therefore the time limit for performing the analysis process of FIG. 4 (reference Tcal in FIG. 7). Can be secured for a long time. Therefore, the calculation load on the CPU 34a of the microcomputer 34 can be reduced, and the storage capacity of the memory 34b can be reduced, so that the calculation process can be made more efficient. In particular, the processing for removing the swell component Wc shown in FIG. 5 in the analysis processing has a large processing load on the CPU 34a. Therefore, when such swell component removal processing is performed, the analysis processing is performed intermittently. As a result, the required capacity of the CPU 34a can be greatly reduced.

  Further, according to the present embodiment in which the number of jumps m is set to 1 less than the number of cylinders n, the number of learning of the injection rate parameters td, te, Rα, Rβ, Rmax applied to the fuel injection valve 10 of each cylinder is universal. Therefore, it is possible to avoid deviations in the accuracy of the injection control of each cylinder, and to improve the controllability of the engine output and the exhaust emission.

(Second Embodiment)
In the first embodiment, the fuel injection state analysis device is mounted on a four-cylinder engine, whereas in the present embodiment shown in FIG. 8, the fuel injection state analysis device is mounted on a six-cylinder engine. In this case, the jump number m = 3 shown in FIG. 7 is changed to the jump number m = 5 shown in FIG. The other hardware configurations and the contents of the analysis process in FIG. 4 are the same as those in the first embodiment.

  The numbers in FIG. 8A indicate the order of the cylinder numbers of the injection cylinders, and the injection is performed in the order of # 1 → # 5 → # 3 → # 6 → # 2 → # 4 → # 1 →. Indicates that you will The numbers with halftone dots in FIG. 8A indicate the cylinder numbers of the fuel injection valves 10 to be analyzed for the injection state by the processing of FIG. 4, and # 1 → # 4 → # 2 This indicates that analysis is performed in the order of # 6 # 3 # 3 # 5 # 1 →. That is, after analyzing the injection state for # 1, the analysis according to FIG. 4 is not performed for the injection states in # 5, # 3, # 6, and # 2, and then the injection state is analyzed for # 4.

  In short, in the example of FIG. 8A, the analysis according to FIG. 4 is performed intermittently without continuously performing every injection, and the order in which the injection order is skipped by a predetermined number of jumps m is the analysis order. It is said. The jump number m is set to be one less than the cylinder number n (m = n−1).

  The numbers with halftone dots in FIG. 8B indicate the cylinder numbers of the back cylinders used for obtaining the back waveforms Wu, Wu ′, and # 5 → # 1 → # 4 → # 2 → # 6 → It shows that the back waveforms Wu and Wu ′ are generated in step S10b of FIG. 5 in the order of # 3 → # 5 →. In short, in the example of FIG. 8B, the generation of the back waveforms Wu and Wu ′ according to FIG. 5 is performed intermittently without continuously performing every injection, and the injection order is set to a predetermined number of jumps m. The order of skipping is used as the generation order. The jump number m is set to be the same as the jump number according to FIG. 8A (m = n−1).

  As described above, according to the present embodiment, the analysis processing according to FIG. 4 is performed intermittently without being continuously performed for each injection, so that the calculation load on the CPU 34a is reduced as in the first embodiment. And the storage capacity of the memory 34b can be reduced.

  Further, according to the present embodiment in which the number of jumps m is set to 1 less than the number of cylinders n, the number of learning of the injection rate parameters td, te, Rα, Rβ, Rmax applied to the fuel injection valve 10 of each cylinder is universal. Therefore, it can be avoided that the accuracy of the injection control of each cylinder is biased.

(Third embodiment)
In the first embodiment, the number of jumps m is set to 1 less than the number of cylinders n (m = n−1), and is fixed at one set number of jumps, whereas this embodiment shown in FIG. In the embodiment, the first jump number m1 and the second jump number m2 are set, and the jump is alternately repeated with these jump numbers m1 and m2 to set the analysis order. The other hardware configurations and the contents of the analysis process in FIG. 4 are the same as those in the first embodiment.

  The numbers in FIG. 9A indicate the order of the cylinder numbers of the injection cylinders, and indicate that the injection is performed in the order of # 1 → # 3 → # 4 → # 2 → # 1 →. . The numbers with halftone dots in FIG. 9A indicate the cylinder numbers of the fuel injection valves 10 to be analyzed for the injection state by the processing of FIG. 4, and [# 1 → # 4 → # 3 → # 2] → [# 4 → # 1 → # 2 → # 3] → [# 1 →... That is, in the example of FIG. 7, the analysis cycle is for four analyses, whereas in this embodiment shown in FIG. 9, the analysis cycle is for eight analyses.

  The above-described first jump number m1 is set to a half number of the cylinder number n (m1 = n / 2), and the second jump number m2 is set to a number obtained by adding 1 to half the cylinder number n (m2 = 1 + n / 2).

  The numbers with halftone dots in FIG. 9B indicate the cylinder numbers of the back cylinders used for obtaining the back waveforms Wu, Wu ′, and [# 3 → # 2 → # 4 → # 1] → [ It shows that the back waveforms Wu and Wu ′ are generated in the order of # 2 → # 3 → # 1 → # 4] → [# 3 →... In short, in the example of FIG. 9B, the generation of the back waveforms Wu, Wu ′ according to FIG. 5 is performed intermittently without continuously performing every injection, and the injection order is set to a predetermined number of jumps m. The order of skipping is used as the generation order. The jump number m is set to be the same as the jump number according to FIG. 9A (m = n−1).

  As described above, according to the present embodiment as well, the analysis process of FIG. 4 is intermittently performed, so that the calculation load on the CPU 34a and the storage capacity of the memory 34b are reduced as in the first embodiment. Can do.

  Further, according to this embodiment in which the first jump number m1 and the second jump number m2 are analyzed in the order of jumping alternately, the injection rate parameters td, te, Rα, Rβ applied to the fuel injection valve 10 of each cylinder. , Rmax can be made uniform evenly, so that it is possible to avoid biasing the accuracy of injection control of each cylinder.

  In addition, since the number of times of analysis can be increased as compared with the example of FIG. 7, the number of times of learning can be increased, and the accuracy of injection control can be improved. However, in the present embodiment, the first jump number m1 and the second jump number m2 are alternately jumped, whereas in the example of FIG. 7, the number of jumps is fixed to one. Therefore, in the example of FIG. Compared to this, the calculation program can be simplified.

(Fourth embodiment)
In the third embodiment, the fuel injection state analysis device is mounted on a four-cylinder engine. On the other hand, in the present embodiment shown in FIG. 10, the fuel injection state analysis device is mounted on a six-cylinder engine.

  In this case, the first jump number m1 = 2 and the second jump number m2 = 3 shown in FIG. 9 are changed to the first jump number m1 = 3 and the second jump number m2 = 4 shown in FIG. The other hardware configurations and the contents of the analysis process in FIG. 4 are the same as those in the first embodiment.

  The numbers in FIG. 10 (a) indicate the order of the cylinder numbers of the injection cylinders, and the numbers with halftone dots in FIG. 10 (a) are targets for analyzing the injection state by the processing of FIG. The cylinder number of the fuel injection valve 10 is shown, [# 1 → # 6 → # 5 → # 2 → # 3 → # 4] → [# 6 → # 1 → # 2 → # 5 → # 4 → # 3 ] → [# 1... In the order of analysis.

  That is, in the example of FIG. 9, the analysis cycle is for eight analyses, whereas in this embodiment shown in FIG. 10, the analysis cycle is for sixteen analyses.

  The above-mentioned first jump number m1 is set to a half number of the cylinder number n (m1 = n / 2), and the second jump number m2 is set to a number obtained by adding 1 to half the cylinder number n (m1). = 1 + n / 2).

  The numbers with halftone dots in FIG. 10B indicate the cylinder numbers of the back cylinders used for obtaining the back waveforms Wu, Wu ′. [# 5 → # 2 → # 3 → # 4 → # 6 → # 1] → [# 2 → # 5 → # 4 → # 3 → # 1 → # 6] → [# 5..., The back waveforms Wu and Wu ′ are generated in step S10b of FIG. Indicates that you are going. In short, in the example of FIG. 10B, the generation of the back waveforms Wu and Wu ′ according to FIG. 5 is intermittently performed without continuously performing every injection, and the injection order is set to a predetermined number of jumps m1. , M2 is the generation order. The jump numbers m1 and m2 are set to be the same as the jump number according to FIG.

  As described above, according to the present embodiment as well, the analysis process of FIG. 4 is intermittently performed, so that the calculation load on the CPU 34a and the storage capacity of the memory 34b are reduced as in the first embodiment. Can do.

  Further, according to this embodiment in which the first jump number m1 and the second jump number m2 are analyzed in the order of jumping alternately, the injection rate parameters td, te, Rα, Rβ applied to the fuel injection valve 10 of each cylinder. , Rmax can be made uniform evenly, so that it is possible to avoid biasing the accuracy of injection control of each cylinder.

  Moreover, since the number of analyzes can be increased as compared with the example of FIG. 8, the number of learning can be increased, and the accuracy of injection control can be improved. However, in the present embodiment, the first jump number m1 and the second jump number m2 are alternately jumped, whereas in the example of FIG. 8, the number of jumps is fixed to one, so in the example of FIG. Compared to this, the calculation program can be simplified.

(Fifth embodiment)
In each of the above embodiments, the number of jumps is fixed to preset values m, m1, and m2. However, the higher the rotational speed NE of the crankshaft (output shaft) of the engine, the shorter the time limit Tcal for performing the analysis process of FIG. 4 when the number of jumps is fixed. Therefore, in this embodiment, the jump number is variably set during engine operation.

  More specifically, the higher the engine speed NE, the longer the number of jumps is set to be longer, and the time limit Tcal for the analysis process is made longer. For example, when the engine speed NE exceeds a predetermined threshold and becomes high, the jump number is variably set to a number obtained by adding an integer multiple of the cylinder number n to the jump number set in each of the above embodiments. To do.

  Alternatively, when the engine rotational speed NE is lower than a predetermined threshold, the jump numbers m1 and m2 shown in FIG. 9 or FIG. 10 are set. When the engine rotational speed NE exceeds a predetermined threshold, FIG. The number of jumps m shown in FIG.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  In each of the above embodiments, the jump numbers m, m1, and m2 that determine the order of generating the back waveform Wu are set to be the same as the jump numbers m, m1, and m2 that determine the order of generating the injection waveform Wa. However, different jump numbers may be set.

  In this case, for example, the number of jumps related to the back waveform Wu is set to an integral multiple of the number of jumps related to the injection waveform Wa, and the back waveform Wu used in the previous processing of FIG. 5 is used in the processing of FIG. What is necessary is just to divert to back waveform Wu.

  In each of the above embodiments, the waveform is generated in steps S10a and S10b of FIG. 5 based on a plurality of detection values detected by the fuel pressure sensor 20 at a predetermined sampling period, and the sampling period is set to a predetermined value. However, the sampling period may be variably set during engine operation. For example, the sampling cycle may be set longer as the engine rotational speed NE is higher, thereby reducing the processing load of waveform generation in steps S10a and S10.

  In the third and fourth embodiments, the first jump number m1 is set to half of the cylinder number n and the second jump number m2 is set to “n / 2 + 1”, but “n / 2-1” May be set. In short, when the first jump number m1 is set to half the number of cylinders, the second jump number m2 only needs to be shifted by 1 from the first jump number m1. However, if the number of jumps is set to less than 2, analysis processing must be performed continuously, so it is an essential condition to set the number of jumps to 2 or more.

  In each of the above embodiments shown in FIG. 1, the fuel pressure sensor 20 is mounted on the fuel injection valve 10, but the fuel pressure sensor according to the present invention is a fuel supply path from the discharge port 42a of the common rail 42 to the injection hole 11b. Any fuel pressure sensor may be used as long as it is arranged to detect the fuel pressure inside. Therefore, for example, a fuel pressure sensor may be mounted on the high-pressure pipe 42 b that connects the common rail 42 and the fuel injection valve 10. That is, the high-pressure pipe 42b connecting the common rail 42 and the fuel injection valve 10 and the high-pressure passage 11a in the body 11 correspond to the “fuel passage”.

  In each of the above embodiments, the present invention is applied to a 4-cylinder engine and a 6-cylinder engine. However, the present invention is not limited to these engines, and may be, for example, an 8-cylinder engine.

  In the first embodiment, it is assumed that the number of times the fuel is pumped from the fuel pump 41 is twice in one combustion cycle. For example, the fuel injection system that pumps three times or four times in one combustion cycle The present invention is also applicable.

  DESCRIPTION OF SYMBOLS 10 ... Fuel injection valve, 20 ... Fuel pressure sensor, 31 ... Injection rate parameter calculation means (analysis means), S10-S22 ... Analysis means, S10a ... Injection waveform generation means, S10b ... Back waveform generation means, S11-S22 ... Calculation means , M: number of jumps, m1: first jump number, m2: second jump number.

Claims (5)

A fuel injection valve that is provided in each cylinder of a multi-cylinder internal combustion engine and injects fuel accumulated in a pressure accumulator;
A fuel pressure sensor that is disposed in a fuel passage from a discharge port of the pressure accumulating container to a nozzle hole of the fuel injection valve, and detects a fuel pressure in the fuel passage;
Applied to a fuel injection system comprising:
Analyzing means for analyzing the fuel injection state based on a change in the detected value of the fuel pressure sensor that occurs with fuel injection,
When sequentially injecting fuel from the fuel injection valve of each cylinder, the analysis by the analysis means is performed in the order obtained by jumping a predetermined number of jumps in the injection order ,
The fuel injection state analysis is characterized in that the order of the fuel injection valves to be analyzed among the fuel injection valves of each cylinder is set so as to circulate so that the cumulative number of analyzes for each fuel injection valve is the same. apparatus. 2. The fuel injection state analyzing apparatus according to claim 1, wherein the number of jumps is set to be one less than the number of cylinders. And repeatedly setting the number of jumps alternately between the first jump number and the second jump number,
Set the first jump number to half the number of cylinders,
2. The fuel injection state analysis device according to claim 1, wherein the second jump number is set to a number that is one less than a half of the number of cylinders, a number that is one more than a half of the number of cylinders, and two or more. . The fuel injection state analyzing apparatus according to any one of claims 1 to 3 , wherein the jump number is set to be larger as the rotational speed of the output shaft of the internal combustion engine is higher. In the case where the cylinder that is injecting fuel is an injection cylinder, and the cylinder that is stopped when the fuel is injected in the injection cylinder is a back cylinder,
The analysis means includes
An injection waveform generating means for generating an injection waveform representing a change in a detection value by a fuel pressure sensor in the injection cylinder;
Back waveform generating means for generating a back waveform representing a change in a detection value by a fuel pressure sensor in the back cylinder;
Based on a waveform obtained by subtracting the back waveform from the injection waveform, calculation means for calculating an injection state in the injection cylinder;
Have
When the fuel is sequentially injected from the fuel injection valve of each cylinder, the generation by the injection waveform generation means and the generation by the back waveform generation means are performed in an order obtained by jumping a predetermined number of jumps in the injection order. The fuel injection state analysis device according to any one of claims 1 to 4 , wherein

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