JP2014074369A - Accumulation type fuel injection control device and control method of accumulation type fuel injection control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce injection amount dispersion of an accumulation type fuel injection control device and enable injection control with less error between a target injection amount and an actual injection amount.SOLUTION: This invention relates to an accumulation type fuel injection control device comprising an injector basic correction amount calculation part for calculating a correction amount to a difference between a reference injection amount and an actual injection amount generated by dispersion at the injector, a rail basic correction amount calculation part for calculating a correction amount to a difference between the reference injection amount and the actual injection amount generated by dispersion of orifices provided to a common rail, a post-correction target injection amount calculation part for correcting a target injection amount by using the injector basic correction amount and the rail basic correction amount, and an injector control part for performing drive control of the injector by calculating an injector energization time according to the post-correction target injection amount.

Description

  The present invention relates to an accumulator fuel injection control device and a control method for an accumulator fuel injection control device for injecting fuel into a cylinder of an internal combustion engine. In particular, the present invention relates to an accumulator fuel injection control apparatus and a control method for an accumulator fuel injection control apparatus that can correct a deviation in fuel injection amount due to individual differences in injectors and common rails caused by manufacturing tolerances.

  Conventionally, as an apparatus for injecting fuel into a cylinder of an engine mounted on a vehicle or the like, an accumulator fuel injection control apparatus having a common rail for temporarily storing fuel pressurized by a high-pressure pump has been used. Yes. An injector is connected to the common rail, and energization control of each injector is performed in a state where high-pressure fuel is supplied to each injector, so that fuel is injected into the cylinder of the engine at a desired injection timing.

  In such an accumulator fuel injection control device, it is desired that fuel be injected without excess or deficiency with respect to the required injection amount. For example, in the case of the accumulator fuel injection control device used in the above-described internal combustion engine, if the actual injection amount is excessive or insufficient with respect to the target injection amount, there is a risk of causing exhaust emission, deterioration of vehicle drivability, or the like.

  As a factor that causes an excess or deficiency in the actual injection amount, there is a variation in manufacturing the injector, and a system for correcting the variation in the actual injection amount caused by this variation has been proposed. Specifically, the difference information between the reference injection amount of the injector and the actual injection amount is acquired, information on the basic correction amount with respect to the reference injection amount is obtained, and the target injection amount is corrected using the basic correction amount. A system is disclosed in which a post-target injection amount is calculated, and injector drive control is performed based on a reference injection characteristic and a corrected target injection amount. (For example, see Patent Document 1)

International Publication WO2011 / 039889 Pamphlet

  By the way, in the accumulator fuel injection control device, in order to reduce the pulsation of the fuel pressure caused by the fuel injection from the injector, an orifice is provided at the connecting portion between the fuel pipe for supplying fuel from the common rail to the injector and the common rail. There is a case. This orifice has an effect of reducing the change in the subsequent fuel injection amount due to the pulsation of the fuel pressure caused by the preceding fuel injection when performing the multistage injection in which the fuel is injected a plurality of times during one combustion cycle of the engine.

  On the other hand, the shape of the orifice, such as the inner diameter or the orifice length, may vary depending on the processing conditions. The variation affects the passage of fuel supplied from the common rail to the injector, and consequently the amount of fuel injected from the injector. May lead to variation. However, the system disclosed in Patent Document 1 can reduce the variation in the injection amount due to the manufacturing variation of the injector, but cannot reduce the variation in the injection amount due to the variation in the orifice shape.

  In view of this, the inventors of the present invention have made diligent efforts to correct the variation in the injection amount of the injector by taking into account the variation in the injection amount due to the manufacturing variation of the injector and the variation in the injection amount due to the variation in the orifice shape. The present invention has been completed by finding that such a problem can be solved by calculating the corrected target injection amount by correcting the target injection amount. That is, the present invention provides an accumulator fuel injection control device and a control method for an accumulator fuel injection control device that can perform injection control with less error between a target injection amount and an actual injection amount by reducing variation in injection amount. For the purpose.

  According to the present invention, an injector for supplying fuel to an internal combustion engine, a common rail having an orifice at a connection portion between the injectors, and information on a reference injection characteristic indicating a relationship between a pre-stored injector energization time and a reference injection amount And a control device that performs injection control of the injector by obtaining an injector energization time corresponding to the target injection amount using the control device, wherein the control device is a predetermined injector energization caused by variations in the injector An injector basic correction amount calculation unit that obtains injector difference information that is a difference between the reference injection amount in time and the actual injection amount of the injector and obtains an injector basic correction amount with respect to the reference injection amount, and a predetermined injector caused by variation in orifices Reference injection amount during energization time and injector A basic rail correction amount calculating unit that obtains orifice difference information that is a difference from the injection amount to obtain a basic rail correction amount with respect to the reference injection amount, a target injection amount, and a basic injector correction amount and a basic rail correction amount. A corrected target injection amount calculation unit that corrects the target injection amount, an injector control unit that performs drive control of the injector by obtaining the injector energization time according to the corrected target injection amount using information on the reference injection characteristics, An accumulator fuel injection control device is provided.

  Further, in configuring the pressure accumulation type fuel injection control device of the present invention, the injector assembled to the common rail is determined based on the injector rank determined based on the injector differential information and the orifice rank determined based on the orifice differential information. It is preferable that

  Further, in configuring the pressure accumulation type fuel injection control device of the present invention, the injector assembled to the common rail is determined by the injector rank determined based on the injector difference information and the flow rate of fuel per unit time at a predetermined pressure. It is preferably determined based on the orifice rank.

  In configuring the pressure accumulation type fuel injection control device of the present invention, the injector rank and the orifice rank are quantified, and the injector assembled on the common rail has an absolute value of the sum of the injector rank and the orifice rank. It is preferable that it is determined to be equal to or less than a predetermined value.

  In configuring the accumulator fuel injection control device of the present invention, it is preferable that the injector difference information and the injector rank are printed on the injector, and the orifice difference information and the orifice rank are printed on the common rail.

  Another aspect of the present invention provides an injector for supplying fuel to an internal combustion engine, a common rail having an orifice at a connection portion between the injector, and a reference indicating a relationship between injector energization time and a reference injection amount stored in advance. In a control method of an accumulator type fuel injection control device comprising: a control device that performs injection control of an injector by obtaining an injector energization time corresponding to a target injection amount using information on injection characteristics; Injector difference information, which is the difference between the reference injection amount and the actual injection amount of the injector, is obtained to obtain the basic correction amount of the injector with respect to the reference injection amount, and at the predetermined injector energization time caused by the variation of the orifice Difference between the reference injection amount and the actual injection amount of the injector By obtaining certain orifice difference information and obtaining the basic rail correction amount for the reference injection amount, the target injection amount calculated is corrected using the basic injector correction amount and the basic rail correction amount. A control method for an accumulator fuel injection control apparatus, wherein a corrected target injection amount for obtaining an injection amount is calculated.

  According to the pressure accumulation type fuel injection control device and the control method of the pressure accumulation type fuel injection control device of the present invention, in correcting the injection amount variation of the injector, the variation in the injection amount due to the manufacturing variation of the injector and the variation in the orifice shape Since the target injection amount after correction is calculated by correcting the target injection amount in consideration of the injection amount variation caused by the fuel injection, the injection amount variation is reduced and the error between the target injection amount and the actual injection amount is small The injection control can be executed.

It is a general view which shows the structural example of a pressure accumulation type fuel injection control apparatus. It is an expanded sectional view of the part shown by A in FIG. 1 in the accumulator fuel injection control device. It is a block diagram for demonstrating the example of a structure of the control apparatus in a pressure accumulation type fuel injection control apparatus. It is a figure for demonstrating preparation of the injector basic correction amount map M2_i by a control apparatus. It is a figure for demonstrating preparation of the rail basic correction amount map M2_r by a control apparatus. It is a flowchart which shows an example of the procedure which produces the injector basic correction amount map M2_i and the rail basic correction amount map M2_r in the embodiment of the present invention. It is a flowchart which shows an example of the control method of the fuel injection quantity in embodiment of this invention.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments relating to an accumulator fuel injection control device and an accumulator fuel injection control device according to the present invention will be specifically described below with reference to the drawings as appropriate. However, this embodiment shows one aspect of the present invention and does not limit the present invention, and can be arbitrarily changed within the scope of the present invention. In addition, what attached | subjected the same code | symbol in each figure has shown the same member, and description is abbreviate | omitted suitably.

[First embodiment]
1. Accumulated Fuel Injection Control Device FIG. 1 shows an overall configuration of an accumulator fuel injection control device 10 according to an embodiment of the present invention. The accumulator fuel injection control device 10 is a device for injecting fuel into a cylinder of an internal combustion engine (not shown) mounted on a vehicle, and includes a fuel tank 1, a low pressure pump 11, a high pressure pump 13, and a flow rate. A control valve 19, a common rail 15, a pressure control valve 23, an injector 17, a control device 50 (ECU) and the like are provided as main elements.

  The low pressure pump 11 and the pressurization chamber 13a of the high pressure pump 13 are connected by a low pressure fuel passage 31, and the pressurization chamber 13a and the common rail 15 of the high pressure pump 13 and the common rail 15 and the injector 17 are connected by high pressure fuel passages 33 and 35, respectively. Has been. Further, return passages 37, 38, and 39 for returning surplus fuel not injected from the injector 17 to the fuel tank 1 are connected to the high-pressure pump 13, the common rail 15, and the injector 17, respectively.

  A flow rate control valve 19 for adjusting the flow rate of the fuel sent to the pressurizing chamber 13 a is provided in the middle of the low pressure fuel passage 31 in the high pressure pump 13. As the flow control valve 19, for example, an electromagnetic proportional flow control valve in which the stroke amount of the valve member is variable depending on the supply current value and the area of the fuel passage is adjustable is used. The flow control valve 19 of the present embodiment is configured as a normally open flow control valve in which a fuel flow path is fully opened in a non-energized state. However, it may be a normally closed flow control valve in which the fuel flow path is fully closed in a non-energized state.

  A pressure adjustment valve 21 is provided in the fuel passage that branches from the low-pressure fuel passage 31 upstream of the flow control valve 19 in the high-pressure pump 13. The pressure regulating valve 21 is connected to a return passage 37 that communicates with the fuel tank 1, and the difference between the front and rear pressures, that is, the difference between the pressure in the low-pressure fuel passage 31 and the pressure in the return passage 37 exceeds a predetermined value. An overflow valve that is opened when the valve is opened is used. In a state where the fuel is being pumped by the low pressure pump 11, the pressure in the low pressure fuel passage 31 is adjusted so as to be larger than the pressure in the return passage 37 by a predetermined differential pressure.

  The low pressure pump 11 sucks up and pumps the fuel in the fuel tank 1, and supplies the fuel to the pressurizing chamber 13 a of the high pressure pump 13 through the low pressure fuel passage 31. The low pressure pump 11 is an in-tank electric pump provided in the fuel tank 1 and is driven by a current supplied from a battery. However, the low pressure pump 11 may be provided outside the fuel tank 1 or may be a gear pump that is driven by power of an internal combustion engine (not shown).

  The high pressure pump 13 pressurizes fuel introduced into the pressurizing chamber 13 a via the fuel intake valve 27 by the low pressure pump 11 by the plunger 29, and supplies high-pressure fuel to the common rail via the fuel discharge valve 28 and the high pressure fuel passage 33. 15 is pumped. The fuel discharge valve 28 has a check valve structure in which the sealing performance is enhanced as the pressure in the common rail located on the discharge side (hereinafter referred to as “rail pressure”) increases.

  A cam 14 for driving the high-pressure pump 13 is fixed to a camshaft connected to a driveshaft of an internal combustion engine (not shown) via a gear. The high-pressure pump 13 shown in FIG. 1 includes two plungers 29. The two plungers 29 are pushed up by the cam 14, and the fuel is pressurized in the two pressurizing chambers 13a. The fuel is pumped. Although the high-pressure pump 13 of this embodiment is comprised including the two plungers 29 and the pressurization chamber 13a, the number of plungers is not limited to this.

  The common rail 15 accumulates high-pressure fuel pressurized by the high-pressure pump 13 and supplies the fuel to each injector 17 connected via the high-pressure fuel passage 35. A rail pressure sensor 25 and a pressure control valve 23 are attached to the common rail 15. The sensor signal of the rail pressure sensor 25 is sent to the control device 50, and the rail pressure is detected based on this sensor signal.

  The pressure control valve 23 is used to adjust the flow rate of the high-pressure fuel that is returned from the common rail 15 to the fuel tank 1. The pressure control valve 23 is an electromagnetic proportional control valve in which the stroke amount of the valve member for opening and closing the fuel passage is variable depending on the supply current value, and the area of the fuel passage is adjustable. The pressure control valve 23 of the present embodiment is configured as a normally open pressure control valve in which the fuel flow path is fully opened in a non-energized state. A normally open type pressure control valve opens when the sum of the biasing force of the spring that biases the valve member in the valve opening direction and the rail pressure exceeds the force that biases the valve member in the valve closing direction. .

  The injector 17 includes a nozzle body provided with an injection hole and a nozzle needle that opens and closes the injection hole by advancing and retreating. The injector 17 closes the injection hole by applying a back pressure to the rear end side of the nozzle needle, while opening the injection hole by releasing the loaded back pressure. As the back pressure control means of the injector 17, an electrostrictive actuator provided with a piezo element or an electromagnetic solenoid actuator is used.

  The flow rate control valve 19 and the pressure control valve 23 are energized and controlled by the control device 50. The fuel passage area changes proportionally according to the energization amount (operation amount), and the flow rate of the fuel passing therethrough. Is to be adjusted. In this accumulator fuel injection control device 10, the actual rail pressure detected by the pressure sensor 25 becomes the target rail pressure using the flow rate control valve 19 or the pressure control valve 23, or using both control valves in combination. Control is performed as follows. Whether the rail pressure is controlled using the flow rate control valve 19, the pressure control valve 23, or a combination of these control valves is determined mainly depending on the operating state of the internal combustion engine. ing.

  FIG. 2 is an enlarged cross-sectional view of a portion indicated by a dashed line A in FIG. In the common rail 15, an orifice member 16 having an orifice 16a therein is press-fitted into a connection portion 15a with a high-pressure fuel passage 35 for supplying high-pressure fuel to each injector. As a method of fixing the orifice member 16 to the common rail 15, a method other than press fitting such as welding is also possible. Further, an orifice may be directly formed in the common rail 15.

2. Control unit (ECU)
FIG. 3 is a functional block diagram showing a part related to the present invention in the control device 50 for controlling the accumulator fuel injection control device 10 of the present embodiment. The control device 50 is configured around a microcomputer having a known configuration, and includes an injector basic correction amount calculation unit 51, a rail basic correction amount calculation unit 53, a corrected target injection amount calculation unit 55, and an injector. A control unit 57 and a storage unit 59 are provided. Among these, the memory | storage part 59 is comprised by RAM (Random Access Memory), for example, and various information is memorize | stored beforehand or the various information and operation result which were read are memorize | stored.

(1) Injector Basic Correction Amount Calculation Unit The injector basic correction amount calculation unit 51 calculates a correction amount corresponding to the injection amount variation caused by the manufacturing variation of the injector 17. Specifically, for each injector 17, an injector difference that is a difference between the reference injection amount Qmv (mm ³ / st) and the actual injection amount Qact_0 (mm ³ / st) of the injector 17 at a predetermined rail pressure and injector energization time. to obtain information, to calculate the injector basic correction amount ΔQ0 (mm ³ / st) relative to the reference injection amount Qmv (mm ³ / st). Here, the reference injection amount Qmv (mm ³ / st) is, for example, the value of the injection amount by the reference injector when constructing the fuel injection control logic.

The storage unit 59 stores an injector reference correction coefficient map M1_i in which reference correction coefficients α are set in advance at a plurality of injection points. The injector basic correction amount calculator 51 creates the injector basic correction amount map M2_i by reflecting the acquired injector difference information for each reference correction coefficient α set in the injector reference correction coefficient map M1_i. . That is, an injector basic correction amount ΔQ0 (mm ³ / st) is calculated by using any one of later-described injector difference information ΔPI_0, ΔID_0, ΔEP_0, ΔFL_0 and a reference correction coefficient α at each point, and the result is the injector basic The correction amount map M2_i. The injector basic correction amount map M2_i is stored in the storage unit 59.

FIG. 4 shows a specific example of a calculation process in which the injector basic correction amount map M2_i is obtained by reflecting the injector difference information in the injector reference correction coefficient map M1_i. In this injector reference correction coefficient map M1_i, a reference correction coefficient α in an injection state with different injection amounts is set for each of multiple stages of rail pressure. In the example of FIG. 4, the rail pressure on the horizontal axis is divided into C1 to C5 and the injection state on the vertical axis is divided into R0 to R5 within the range of rail pressure and injection amount that can be actually assumed in accordance with the operating state of the internal combustion engine. The reference correction coefficient α is plotted for each square. Note that C0 on the horizontal axis is the value of the reference injection amount Qmv (mm ³ / st) at R0 to R5 in each injection state.

  Of the injection states R0 to R5 on the vertical axis, R0 is a non-injection state. R1 is, for example, an auxiliary injection execution state before main injection. R2 is an injection state at the time of idling, for example. R3 is an injection state used, for example, for exhaust gas inspection. R4 is, for example, an injection state when a predetermined test operation is performed. R5 is an injection state at the time of full load, for example. Hereinafter, the mass of the injection state Rj when the rail pressure is Ck is expressed as RjCk.

The injector difference information ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0 are calculated in consideration of rail pressures that are actually assumed as the injection states R1, R2, R3, and R5 when the internal combustion engine is operated. For example, the mass R1C3 in the injection state R1 at the rail pressure C3, the mass R2C2 in the injection state R2 at the rail pressure C2, the mass R3C4 in the injection state R3 at the rail pressure C4, and the mass R5C5 in the injection state R5 at the rail pressure C5 At the four inspection points, the respective injector difference information ΔPI_0, ΔID_0, ΔEP_0, ΔFL_0 is obtained by subtracting the reference injection amount Qmv (mm ³ / st) from the actual injection amount Qact_0 (mm ³ / st) of the injector 17 Calculated. That is, when the actual injection amount Qact_0 (mm ³ / st) is larger than the reference injection amount Qmv (mm ³ / st), the injector difference information is a positive number, and vice versa, the injector difference information is a negative number. It becomes.

The calculation of the injector difference information ΔPI_0, ΔID_0, ΔEP_0, ΔFL_0 is performed in the manufacturing stage of the injector 17, and the actual injection amount Qact_0 (mm ³ / st) used at this time is the same as that at the time of manufacturing the injector 17. Inspection data can be diverted. In the measurement, the influence of the variation of the orifices 16a is excluded from the injector difference information by using the common rail 15 having the orifices 16a defined as a standard or equipment equivalent thereto.

Further, the reference correction coefficient α plotted in the injector reference correction coefficient map M1_i is associated in advance with any of the above-described inspection points R1C3, R2C2, R3C4, R5C5. Which difference information is associated with the reference correction coefficient α of each mass is determined at the stage of development of the accumulator fuel injection control device. In the present embodiment, the reference correction coefficients α _R1C3 , α _R2C2 , α _R3C4 , and α _R5C5 are 1 for the masses R1C3, R2C2, R3C4, and R5C5 that are the inspection points described above.

The basic injector correction amount ΔQ0 (mm ³ / st) in each square is obtained by the product of the reference correction coefficient α and the injector difference information associated with each reference correction coefficient α. That is, the injector base correction amount .DELTA.Q0 _RjCk in the mass RjCk is
ΔQ0 _RjCk = −α _RjCk × ΔX
(However, ΔX is one of ΔPI_0, ΔID_0, ΔEP_0, or ΔFL_0)
Is calculated as _Further , the minus sign before α _RjCk indicates that ΔX is a positive number, that is, when the actual injection amount Qact_0 is larger than the reference injection amount Qmv, the injector basic correction amount ΔQ0 _RjCk is a negative number, while ΔX is negative. When the number, that is, Qact_0 is smaller than the reference injection amount Qmv, it means that the injector basic correction amount ΔQ0 _RjCk is a positive number.

  Here, in the present embodiment, as the information transmission means for the control device 50 to acquire the injector difference information ΔPI_0, ΔID_0, ΔEP_0, ΔFL_0, the injector difference information converted into the barcode at the manufacturing stage of the injector 17 is used. A means for printing at 17 appropriate positions and reading with a camera when the accumulator fuel injection control device is assembled is adopted. However, the information transmission means is not limited to that described above, and it is also possible for the operator to input injector difference information converted into an alphanumeric code or the like. Further, information such as a bar code or alphanumeric code can be printed on a label or the like and attached to the injector 17.

After obtaining the injector difference information, the basic correction amount ΔQ0 (mm ³ / st) at each injection point RjCk, that is, each injection point is calculated by the calculation described above, and the injector basic correction amount map M2_i is created. . In the present embodiment, since the basic correction amount ΔQ0 (mm ³ / st) of many injection points can be obtained based on relatively small injector difference information, the number of work steps for obtaining the difference information for each injector 17 Has been reduced.

The number of injection states Rj and rail pressures Ck forming each mass RjCk on which the reference correction coefficient α and the injector basic correction amount ΔQ0 (mm ³ / st) are plotted may be larger or smaller than the example of FIG. Also good. The more the number of injection states and rail pressure stages, the more accurately the target injection amount Qtp (mm ³ / st) after correction can be obtained, but it must be done in advance to create the injector reference correction coefficient map M1_i Work man-hours increase. The number of stages of the injection state and the rail pressure can be appropriately set in consideration of the required injection accuracy and cost.

(2) Rail Basic Correction Amount Calculation Unit The rail basic correction amount calculation unit 53 calculates a correction amount corresponding to the injection amount variation caused by the manufacturing variation of the orifices 16a in the common rail 15. Specifically, for each orifice member 16 of the common rail 15, the difference between the reference injection amount Qmv (mm ³ / st) at a predetermined rail pressure and injector energization time and the actual injection amount Qact_1 (mm ³ / st) of the injector 17 It acquires orifice differential information is to calculate a rail base correction amount ΔQ1 (mm ³ / st) relative to the reference injection amount Qmv (mm ³ / st).

The storage unit 59 stores a rail reference correction coefficient map M1_r in which reference correction coefficients β are set in advance at a plurality of injection points. The rail basic correction amount calculation unit 53 reflects the acquired orifice difference information for each reference correction coefficient β set in the rail reference correction coefficient map M1_r, and creates a rail basic correction amount map M2_r. . That is, the rail basic correction amount ΔQ1 (mm ³ / st) is calculated using any of the orifice difference information ΔPI_1, ΔID_1, ΔEP_1, ΔFL_1, which will be described later, and the reference correction coefficient β at each point. This is the correction amount map M2_r. The rail basic correction amount map M2_r is stored in the storage unit 59.

FIG. 5 shows a specific example of a calculation process for obtaining the rail basic correction amount map M2_r by reflecting the orifice difference information in the rail reference correction coefficient map M1_r. Orifice difference information ΔPI_1, ΔID_1, ΔEP_1, and ΔFL_1 are the same as in the previous injector basic correction amount calculation, with the actual injection amount Qact_1 (mm ³ / st. ) Is subtracted from the reference injection amount Qmv (mm ³ / st). That is, when the actual injection amount Qact_1 (mm ³ / st) is larger than the reference injection amount Qmv (mm ³ / st), the orifice difference information is a positive number, and vice versa, the orifice difference information is a negative number. It becomes.

The calculation of the orifice difference information ΔPI_1, ΔID_1, ΔEP_1, ΔFL_1 is performed at the manufacturing stage of the common rail 15, and the actual injection amount Qact_1 (mm ³ / st) used at that time is calculated when the common rail 15 is manufactured. Measurement is performed using an injector 17 defined as a standard. Thereby, the influence of the dispersion | variation in the injector 17 is excluded from orifice difference information.

The rail basic correction amount ΔQ1 (mm ³ / st) in each square is obtained by the product of the reference correction coefficient β and the orifice difference information associated with each reference correction coefficient β. That is, the rail base correction amount .DELTA.Q1 _RjCk in the mass RjCk is
ΔQ1 _RjCk = −β _RjCk × ΔY
(However, ΔY is one of ΔPI_1, ΔID_1, ΔEP_1, or ΔFL_1)
Is calculated as In addition, the minus sign before β _RjCk indicates that ΔY is a positive number, that is, if the actual injection amount Qact_1 is larger than the reference injection amount Qmv, the rail basic correction amount ΔQ1 _RjCk is negative, while ΔY is negative. When the number, that is, Qact_1 is smaller than the reference injection amount Qmv, it means that the basic rail correction amount is a positive number.

  Here, as the difference information transmission means for the control device 50 to acquire the orifice difference information ΔPI_1, ΔID_1, ΔEP_1, ΔFL_1, in the present embodiment, the orifice difference information converted into the bar code at the manufacturing stage of the common rail 15 is used. A means is used which is printed on the common rail 15 and read by a camera when the accumulator fuel injection control device is assembled. At that time, since the orifice difference information exists for the number of cylinders of the engine, it is preferable to print a barcode for each target orifice near the orifice 16a of the common rail 15. However, the information transmission means is not limited to that described above, and the operator can input the orifice difference information converted into an alphanumeric code or the like. Further, information such as a bar code or alphanumeric code can be printed on a label or the like and attached to the common rail 15.

After acquiring the orifice difference information, each mass RjCk, that is, the basic rail correction amount ΔQ1 (mm ³ / st) at each injection point is calculated by the above-described calculation, and the basic rail correction amount map M2_r is created. . In the present embodiment, as in the case of calculating the injector basic correction amount, the rail basic correction amount ΔQ1 (mm ³ / st) for many injection points can be obtained based on relatively small orifice difference information. The work man-hours for obtaining the difference information for each are reduced.

(3) Corrected target injection amount calculation unit The corrected target injection amount calculation unit 55 reads the rotational speed Ne of the internal combustion engine, the accelerator operation amount Acc, and the like, and the target injection amount Qdemand () of fuel to be injected into the cylinder of the internal combustion engine mm ³ / st) and the target injection amount Qdemand (mm ³ / st) is corrected for each injector 17 using the injector basic correction amount map M2_i and the rail basic correction amount map M2_r. The quantity Qtp (mm ³ / st) is calculated.

The corrected target injection amount calculation unit 55 of the control device 50 of the present embodiment first reads the rotational speed Ne of the internal combustion engine, the accelerator operation amount Acc, and the like, and uses a predetermined calculation formula and map information to perform the target by a known method. The injection amount Qdemand (mm ³ / st) is obtained, and the rail pressure signal Sp of the rail pressure sensor 25 is read to obtain the current rail pressure Prail_act. Further, the corrected target injection amount calculating unit 55, the current rail pressure Prail_act and the target injection amount Qdemand injector base corresponding to (mm ³ / st) correction amount ΔQ0 a (mm ³ / st) in the injector base correction amount map M2_i Based on the rail basic correction amount map M2_r, the basic rail correction amount ΔQ1 (mm ³ / st) corresponding to the current rail pressure Prail_act and the target injection amount Qdemand (mm ³ / st) is calculated.

When determining the injector basic correction amount ΔQ0 (mm ³ / st) and the rail basic correction amount ΔQ1 (mm ³ / st) according to the current rail pressure Prail_act and the target injection amount Qdemand (mm ³ / st), for example, In the area between adjacent cells (for example, RjCk and Rj-1Ck, or RjCk and RjCk-1) in each map, the basic injector correction amount ΔQ0 (mm ³ / st) and the basic rail correction amount ΔQ1 (mm ³ Assuming that / st) changes proportionally, values corresponding to the actual rail pressure Prail_act and the target injection amount Qdemand (mm ³ / st) can be obtained. Alternatively, the injector basic correction amount ΔQ0 (mm ³ / st) of the injection point that approximates the actual rail pressure Prail_act and the target injection amount Qdemand (mm ³ / st) of each mass (injection point) RjCk of each map Alternatively, the basic rail correction amount ΔQ1 (mm ³ / st) may be selected.

The corrected target injection amount calculation unit 55 calculates the injector basic correction amount ΔQ0 (mm ³ / st) and the rail basic correction amount ΔQ1 (mm ³ / st) obtained in this manner as the target injection amount Qdemand (mm ³ / st) is added to obtain the corrected target injection amount Qtp (mm ³ / st).

(4) Injector Control Unit In the control device 50, reference injection characteristics indicating the relationship between the energization time ET of the injector 17 and the reference injection amount are stored in advance for each rail pressure Prail_act. The injector control unit 57 reads the rail pressure Prail_act and energizes the injector 17 corresponding to the read rail pressure Prail_act and the corrected target injection amount Qtp (mm ³ / st) calculated by the corrected target injection amount calculation unit 55. The time ET is obtained from the reference injection characteristic information, and an energization instruction to the injector 17 is given.

3. Flow of target injection amount correction method and injection control method Next, a fuel injection amount control method performed by the control device 50 will be described with reference to the flowcharts of FIGS. 6 and 7.

  FIG. 6 is a process for creating the injector basic correction amount map M2_i and the rail basic correction amount map M2_r, and is executed only once when the accumulator fuel injection control device according to the present embodiment is assembled to the engine.

  Hereinafter, the process of FIG. 6 will be described. First, in step S102, the injector difference information ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0 of each injector 17 is acquired. In the present embodiment, the injector difference information printed as a barcode on each injector 17 is read by the camera. However, as described in the description of the injector basic correction amount calculation unit 51, the injector difference information can be acquired by other information transmission means.

  In subsequent step S104, an injector basic correction amount map M2_i is created from the injector reference correction coefficient map M1_i and the injector difference information ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0 acquired in step S102, and is stored in the storage unit 59 of the control device 50. Remembered. The injector reference correction coefficient map M1_i is created in the development stage of the accumulator fuel injection control device as described above and is stored in the storage unit 59 of the control device 50 in advance.

  In step S106, acquisition of orifice difference information ΔPI_1, ΔID_1, ΔEP_1, ΔFL_1 for each orifice member 16 incorporated in the common rail 15 is performed. In the present embodiment, orifice difference information printed as a barcode on each common rail 15 is read by a camera. However, as described in the description of the rail basic correction amount calculation unit 53 above, the orifice difference information can be acquired by other information transmission means.

  In step S108, a rail basic correction amount map M2_r is created from the rail reference correction coefficient map M1_r and the orifice difference information ΔPI_1, ΔID_1, ΔEP_1, ΔFL_1 acquired in step S106 and stored in the storage unit 59 of the control device 50. Is done. The rail reference correction coefficient map M1_r is created at the development stage of the pressure accumulation type fuel injection control device as described above, and is stored in the storage unit 59 of the control device 50 in advance.

  FIG. 7 is a flowchart showing a method of controlling the fuel injection amount performed during operation of the internal combustion engine. Hereinafter, the process of FIG. 7 will be described. First, in step S202, the target injection amount Qdemand is calculated from information such as the rotational speed Ne of the internal combustion engine and the accelerator operation amount Acc, and the rail pressure Prail_act is calculated based on the rail pressure signal Sp of the rail pressure sensor 25.

  Next, in step S204, the injector basic correction amount ΔQ0 corresponding to the target injection amount Qdemand and the rail pressure Prail_act is calculated using the injector basic correction amount map M2_i created in the previous step S104.

  In step S206, the basic rail correction amount ΔQ1 corresponding to the target injection amount Qdemand and the rail pressure Prail_act is calculated using the basic rail correction amount map M2_r created in the previous step S108.

  In step S208, the corrected target injection amount Qtp is calculated by adding the target injection amount Qdemand, the injector basic correction amount ΔQ0, and the rail basic correction amount ΔQ1.

  In step S210, the energization time ET of the injector 17 corresponding to the corrected target injection amount Qtp and the rail pressure Prail_act is calculated from predetermined reference injection characteristics, and injector drive control is performed.

  In the present embodiment, the injector reference correction coefficient map M1_i and the rail reference correction coefficient map M1_r are created at the development stage of the accumulator fuel injection control device, stored in the control device 50 in advance, and injector difference information ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0 are calculated at the injector 17 manufacturing stage, and orifice difference information ΔPI_1, ΔID_1, ΔEP_1, and ΔFL_1 are calculated at the manufacturing stage of the common rail 15. When the accumulator fuel injection control device is assembled to the engine, an injector basic correction amount map M2_i and a rail basic correction amount map M2_r are created using these pieces of information. Therefore, the present invention can be implemented even when the control device 50, the injector 17, and the common rail 15 are manufactured at different manufacturing bases.

  As described above, according to the pressure accumulation type fuel injection control device and the control method of the pressure accumulation type fuel injection control device of the present invention, in correcting the injection amount variation of the injector, the injection amount due to the manufacturing variation of the injector is reduced. In order to calculate the corrected target injection amount by correcting the target injection amount in consideration of the variation and the variation in the injection amount due to the variation in the orifice shape, the target injection amount and the actual injection amount are reduced by reducing the injection amount variation. The injection control with a small error from the injection amount can be executed. In addition, according to the present invention, since the variation in the injection amount due to the variation in the orifice shape is suppressed, it is possible to widen the manufacturing tolerance in the processing stage of the orifice 16a.

[Second Embodiment]
The second embodiment takes into account the injector rank determined based on the injector differential information and the orifice rank determined based on the orifice differential information in addition to the first embodiment described above, and the accumulator fuel It constitutes an injection control device. Hereinafter, a description will be given centering on differences from the first embodiment.

  The injector rank is a numerical value determined for each injector 17 based on the magnitudes of the injector difference information ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0 described in the first embodiment, and the injector rank in this embodiment has three levels. It has become. In each injector 17, when the value based on the magnitude of the injector difference information is smaller than the predetermined value on the minus side, the injector rank IR = -1, and the value based on the magnitude of the injector difference information is greater than the predetermined value on the plus side. Is larger, the injector rank IR = + 1. When the value based on the injector difference information is not less than the predetermined value on the minus side and not more than the predetermined value on the plus side, the injector rank IR = 0.

  That is, the injector rank IR = −1 indicates an injector having a relatively small injection amount than the reference injection amount Qmv, while the injector rank IR = + 1 indicates an injector having a relatively large injection amount than the reference injection amount Qmv. An injector rank IR = 0 indicates an injector having an injection amount close to the reference injection amount Qmv.

  In this embodiment, the injector rank IR based on the injector difference information is determined by the average value of each point of the injector difference information ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0. However, how to determine the injector rank IR from the injector difference information can be appropriately determined according to the specifications of the engine and the accumulator fuel injection control device. For example, one specific point in ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0 may be used, or a plurality of specific points may be used.

  Like the injector difference information ΔPI_0, ΔID_0, ΔEP_0, and ΔFL_0, the injector rank IR is calculated at the manufacturing stage of the injector 17, and is printed at an appropriate position of the injector 17 in the present embodiment. Alternatively, it may be printed on a label or the like and attached to the injector 17. However, it is preferable to print the injector rank and the injector difference information at the same location.

  The orifice rank is a numerical value determined for each orifice member 16 based on the size of the orifice difference information ΔPI_1, ΔID_1, ΔEP_1, ΔFL_1 described in the first embodiment, and the orifice rank in the present embodiment is 3 It has become a stage. In each orifice member 16, when the value based on the magnitude of the orifice difference information is smaller than the predetermined value on the minus side, the orifice rank RR = −1, and the value based on the magnitude of the orifice difference information is set to the predetermined value on the plus side. Is larger than the orifice rank RR = + 1. Further, when the value based on the orifice difference information is not less than a predetermined value on the minus side and not more than a predetermined value on the plus side, the orifice rank RR = 0.

  That is, the orifice rank RR = −1 indicates that the orifice has a small flow rate and the injection amount from the injector 17 is relatively smaller than the reference injection amount Qmv, while the orifice rank RR = + 1 indicates that the orifice This is an orifice in which the flow rate is large and the injection amount from the injector 17 is relatively larger than the reference injection amount Qmv. The orifice rank RR = 0 indicates that the orifice has a flow rate close to the average and the injection amount from the injector 17 is close to the reference injection amount Qmv.

  It should be noted that how the orifice rank is determined based on the orifice difference information can be appropriately determined according to the specifications of the engine and the accumulator fuel injection control device, as in the case of the injector rank described above.

  The orifice rank RR is calculated at the manufacturing stage of the common rail 15 similarly to the orifice difference information ΔPI_1, ΔID_1, ΔEP_1, and ΔFL_1. In the present embodiment, the orifice rank RR is printed at an appropriate position on the common rail 15. Alternatively, it may be printed on a label or the like and attached to the common rail 15. However, the orifice rank and the orifice difference information are preferably printed at the same location.

  When assembling the pressure accumulation type fuel injection control device in the present embodiment to the engine, the operator determines the common rail 15 and the injector 17 to be assembled in consideration of the orifice rank RR and the injector rank IR. Specifically, the common rail 15 to be used is determined first, and then the injector 17 used for the common rail 15 is determined so that the sum of the orifice rank RR and the injector rank IR becomes zero.

  That is, the injector rank IR = + 1 for the orifice 16a with the orifice rank RR = −1, and the injector 17 with the injector rank IR = 0 for the orifice 16a with the orifice rank RR = 0. The injector 17 having the injector rank IR = -1 is assembled to the orifice 16a having RR = + 1.

  After the common rail 15 and the injector 17 to be used are determined and the accumulator fuel injection control device is assembled to the engine, the injector basic correction amount map M2_i and the rail are followed according to the flow shown in FIG. 6 as in the first embodiment. The basic correction amount map M2_r is generated by the control device 50. Further, the control method of the fuel injection amount performed during the operation of the internal combustion engine is also performed by the flow shown in FIG. 7 as in the first embodiment.

  In this embodiment, the injector rank and the orifice rank are set in three stages. However, the number of ranks can be determined as appropriate according to the specifications of the engine and the accumulator fuel injection control device. Further, the absolute value of the sum of the orifice rank RR and the injector rank IR can be made to be a predetermined value or less.

  For example, it is possible to determine the common rail 15 and the injector 17 to be used so that the orifice rank RR and the injector rank IR are five stages and the absolute value of the sum of the orifice rank RR and the injector rank IR is 2 or less. It is.

  According to the second embodiment, the sum of the injector basic correction amount ΔQ0 and the rail basic correction amount ΔQ1 is smaller than that of the first embodiment. Accordingly, the difference between the target injection amount Qtp after correction obtained by adding the target injection amount Qdemand, the injector basic correction amount ΔQ0, and the rail basic correction amount ΔQ1 and the target injection amount Qdemand becomes small. The correction amount of the energization time ET can be minimized. The significance of this will be described below.

  In the injection amount correction according to the present invention, as shown in step S210 of FIG. 7, the energization time ET of the injector 17 corresponding to the corrected target injection amount Qtp and the rail pressure Prail_act is calculated from predetermined reference injection characteristics. Is done. In other words, the actual injection amount Qact is matched with the target injection amount Qdemand by correcting the energization time ET of the injector 17 via the corrected target injection amount Qtp. Therefore, the corrected energization time ET of the injector 17 for injecting the target injection amount Qdemand has a slight deviation from the energization time ET defined in the reference injection characteristics.

  On the other hand, when the accumulator fuel injection control device performs multi-stage injection, a time (hereinafter referred to as “interval”) between the preceding injection and the subsequent injection is set. At that time, even if the energization time ET of the injector for the preceding injection becomes longer due to the correction, the interval needs to be set to such a length that the preceding injection ends before the start of the subsequent injection. As a result, there is a concern about an adverse effect on exhaust gas due to an increase in the total injection time. However, according to the second embodiment, the amount of change in the energization time ET of the injector 17 can be minimized, and adverse effects on the exhaust gas can be prevented.

  As described above, according to the pressure accumulation type fuel injection control device and the control method of the pressure accumulation type fuel injection control device of the second embodiment of the present invention, the injection is performed as in the case of the first embodiment. Variations in the amount can be reduced, and injection control with less error between the target injection amount and the actual injection amount can be executed. In addition, according to the present invention, since the variation in the injection amount due to the variation in the orifice shape is suppressed, it is possible to widen the manufacturing tolerance in the processing stage of the orifice 16a.

  In addition, according to the second embodiment of the present invention, the difference between the corrected target injection amount Qtp and the target injection amount Qdemand is reduced while simultaneously reducing variations in the injection amount caused by both the injector 17 and the orifice 16a. By doing so, it is possible to minimize the amount of change in the energization time ET of the injector 17 due to the correction. As a result, the degree of freedom in setting the interval is widened, and adverse effects on the exhaust gas due to an increase in the total injection time can be prevented.

  Note that the second embodiment can also be implemented even when the control device 50, the injector 17, and the common rail 15 are manufactured at different manufacturing bases, as in the first embodiment.

[Third embodiment]
In the second embodiment described above, the orifice rank RR is determined based on the orifice difference information ΔPI_1, ΔID_1, ΔEP_1, ΔFL_1. However, in the third embodiment described below, the orifice rank RR The determination method is different from that of the second embodiment.

  The quality of the orifice 16a at the time of manufacture is controlled by the flow rate of fuel per unit time at a predetermined pressure. The smaller the orifice diameter or the longer the length of the orifice portion, the smaller the flow rate per unit time. Become. Further, the smaller the passage flow rate per unit time of the fuel in the orifice portion, the smaller the injection amount of the injector 17, and the larger the passage flow rate per unit time, the larger the injection amount of the injector 17 tends to be.

  In the third embodiment, using this tendency, the correlation between the flow rate of fuel per unit time in the orifice 16a and the injection amount of the injector 17 is acquired in advance at the development stage of the pressure accumulation type fuel injection control device. The orifice rank RR is determined from the flow rate per unit time of the orifice 16a actually used. In addition, the inspection data in the manufacturing stage of the common rail 15 or the orifice member 16 can be diverted about the flow volume per unit time of the fuel in the orifice 16a.

  In the assembly stage of the accumulator fuel injection control device, as in the second embodiment, the sum of the orifice rank RR and the injector rank IR is 0 or the absolute value of the sum is a predetermined value for the common rail 15 to be used. The injector 17 to be used is determined as follows.

  After the common rail 15 and the injector 17 to be used are determined and the accumulator fuel injection control device is assembled to the engine, an injector basic correction amount map according to the flow shown in FIG. 6 as in the first and second embodiments. The control device 50 creates M2_i and the basic rail correction amount map M2_r. Further, the method for controlling the fuel injection amount performed during the operation of the internal combustion engine is also performed according to the flow shown in FIG. 7, as in the first and second embodiments.

  Also in the third embodiment, as in the above-described embodiment, it is possible to reduce the injection amount variation and execute the injection control with a small error between the target injection amount and the actual injection amount. In addition, since the variation in the injection amount due to the variation in the orifice shape is suppressed, it is possible to widen the manufacturing tolerance in the processing stage of the orifice 16a. Furthermore, the degree of freedom of setting the interval is widened, and the adverse effect on the exhaust gas due to the increase in the total injection time can be prevented.

Note that the third embodiment can be implemented even when the control device 50, the injector 17, and the common rail 15 are manufactured at different manufacturing bases, as in the above-described embodiment.

DESCRIPTION OF SYMBOLS 1: Fuel tank, 10: Accumulation type fuel injection control apparatus, 11: Low pressure pump, 13: High pressure pump, 13a: Pressurization chamber, 14: Cam, 15: Common rail, 15a: Connection part, 16: Orifice member, 16a orifice , 17: Injector, 19: Flow control valve, 23: Pressure control valve, 25: Rail pressure sensor, 27: Fuel intake valve, 28: Fuel discharge valve, 29: Plunger, 31: Low pressure fuel passage, 33, 35: High pressure Fuel path 37, 38, 39: Return path 50: Control device 51: Injector basic correction amount calculation unit 53: Rail basic correction amount calculation unit 55: Corrected target injection amount calculation unit 57: Injector control unit 59: Storage unit

Claims (6)

An injector for supplying fuel to the internal combustion engine;
A common rail provided with an orifice in the connection with the injector;
A control device that performs injection control of the injector by obtaining an injector energization time corresponding to the target injection amount using information of a reference injection characteristic indicating a relationship between the injector energization time and the reference injection amount stored in advance;
In the accumulator fuel injection control device comprising:
The control device includes:
Injector basic correction for obtaining injector basic correction amount for the reference injection amount by acquiring injector difference information, which is a difference between the reference injection amount and the actual injection amount of the injector during a predetermined injector energization time, which is caused by variations in the injector A quantity calculation unit;
Rail basic correction for obtaining a basic rail correction amount for the reference injection amount by obtaining orifice difference information, which is a difference between the reference injection amount and the actual injection amount of the injector during a predetermined injector energization time, which is caused by variations in the orifice. A quantity calculation unit;
A corrected target injection amount calculation unit that calculates the target injection amount using the injector basic correction amount and the rail basic correction amount while obtaining a target injection amount;
An injector control unit that performs drive control of the injector by obtaining an injector energization time according to the corrected target injection amount using information on the reference injection characteristic;
An accumulator fuel injection control device comprising:   The said injector assembled | attached to the said common rail is determined based on the injector rank defined based on the said injector difference information, and the orifice rank defined based on the said orifice difference information. Accumulator fuel injection control device.   The injector assembled to the common rail is determined based on an injector rank determined based on the injector difference information and an orifice rank determined based on a flow rate of fuel per unit time at a predetermined pressure. The accumulator fuel injection control device according to claim 1.   The injector rank and the orifice rank are quantified, and the injector assembled to the common rail is determined so that the absolute value of the sum of the injector rank and the orifice rank is a predetermined value or less. The pressure accumulation type fuel injection control device according to claim 2 or 3, wherein the pressure accumulation type fuel injection control device is a thing.   The accumulator fuel injection control device according to claim 4, wherein the injector difference information and the injector rank are printed on the injector, and the orifice difference information and the orifice rank are printed on the common rail. An injector for supplying fuel to the internal combustion engine;
A common rail provided with an orifice in the connection with the injector;
A control device that performs injection control of the injector by obtaining an injector energization time corresponding to the target injection amount using information of a reference injection characteristic indicating a relationship between the injector energization time and the reference injection amount stored in advance;
In the control method of the pressure accumulation type fuel injection control device comprising:
While obtaining injector difference information, which is a difference between the reference injection amount and the actual injection amount of the injector during a predetermined injector energization time, which is caused by variations in the injector, and obtaining an injector basic correction amount for the reference injection amount,
Obtaining the orifice difference information, which is the difference between the reference injection amount and the actual injection amount of the injector during a predetermined injector energization time caused by the variation of the orifice, and obtaining the rail basic correction amount for the reference injection amount,
The calculated target injection amount is corrected using the injector basic correction amount and the rail basic correction amount, and a corrected target injection amount for obtaining the target injection amount is calculated by the injector. A control method for an accumulator fuel injection control device.

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