JP2009114922A - Accumulator fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accumulator fuel injection device capable of improving the precision of injection amount corresponding to the expansion of a detection range due to pressure increase of fuel injection pressure. <P>SOLUTION: The accumulator fuel injection device accumulates high pressure fuel corresponding to the injection pressure of fuel in a common rail 1, and distributes and supplies the high pressure fuel accumulated in the common rail 1 into injectors 2 mounted on each cylinder of an engine 100. The accumulator fuel injection device comprises a Pc sensor 15 provided on the common rail 1 and outputting output voltage V corresponding to the injection pressure of the fuel, and an information code 71 memorizing errors Δ0, Δ2 of the output voltage V which is output characteristic PcVp of the Pc sensor 15. The information code 71 is attached to the Pc sensor 15 or the common rail 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an accumulator fuel injection device.

  Conventionally, high-pressure fuel is compressed and stored in a common rail by a fuel supply pump that is driven by an engine such as a multi-cylinder diesel engine, and the high-pressure fuel stored in the common rail is mounted on each cylinder of the engine. There is known an accumulator fuel injection device that distributes the fuel to the injector and injects it into the combustion chamber of each cylinder (see Patent Document 1, etc.).

  In this type of fuel injection device, the fuel pressure in the common rail is detected as an actual common rail pressure by a single fuel pressure sensor, and the actual common rail pressure substantially matches the target common rail pressure set based on the operating state of the engine. As described above, the discharge amount control for feedback control of the discharge amount of the fuel supply pump is performed. Also, injection amount control is performed to calculate the injection pulse width based on the target injection amount set based on the actual common rail pressure and the operating state of the engine, and to energize the injector with an injection drive signal corresponding to the injection pulse width. is doing.

  With the recent tightening of exhaust gas regulations, a technique for absorbing individual differences among injectors in order to respond to a request for highly accurate injection control, that is, an improvement in injection amount accuracy, even for an accumulator fuel injection device (Patent Document 2) And a technique that incorporates learning control in injection control (see Patent Document 3) has been proposed.

Specifically, in the technique disclosed in Patent Document 2, the injection characteristic of each injector is measured in advance, and correction data of an injection amount control signal (injection drive signal) corresponding to the injection characteristic is stored in an information storage medium. By attaching the information storage medium to the injector, each injector incorporated in the engine is identified by the information storage medium, and an injection amount correction calculation according to the injection characteristic of each injector is added to absorb individual differences of the injectors. It is.
Japanese Examined Patent Publication No. 7-122422 JP 2002-276503 A JP 2000-186603 A

  However, in the prior art according to the above-mentioned patent document, the injection amount variation due to the individual difference of the injector can be corrected by the correction data of the injection amount control signal stored in the information storage medium, but the injection amount control signal is set. In this case, the variation of the actual common rail pressure detected by the basic common rail fuel pressure sensor is not taken into consideration.

  As a result of intensive studies on the pressure accumulation type fuel injection device having a configuration as disclosed in Patent Document 2 and the like, the inventors have found the following matters.

  That is, first, the initial characteristic variation tends to increase as the detected pressure increases. In other words, with the recent tightening of exhaust gas regulations, it is required to increase the fuel injection pressure of the accumulator fuel injection device, and the detection range of the actual common rail pressure tends to expand compared to the conventional, In the prior art, there is a problem that the injection amount accuracy is lowered due to individual differences in the fuel pressure sensor.

  Next, in the deterioration characteristics, the pressure variation after deterioration tends to increase compared to the initial state, but the pressure characteristics after deterioration increase or decrease compared to the initial state depending on the use environment and use conditions. For example, it is difficult to predict the deterioration characteristics in advance.

  The present invention has been made in view of such circumstances, and provides a pressure accumulation type fuel injection device capable of increasing the accuracy of the injection amount corresponding to the expansion of the detection range by increasing the fuel injection pressure. There is to do.

  In order to achieve the above object, the present invention comprises the following technical means.

That is, in the invention according to any one of claims 1 to 6, the high pressure fuel corresponding to the fuel injection pressure is accumulated in the common rail, and the high pressure fuel accumulated in the common rail is mounted on each cylinder of the internal combustion engine. In the accumulator fuel injector distributed and supplied to
A pressure sensor that is provided on the common rail and outputs a fuel pressure signal corresponding to the fuel injection pressure; and a pressure sensor individual difference storage medium that stores an error in the fuel pressure signal of the pressure sensor. Attached to the pressure sensor or common rail.

  In this invention, the fuel pressure in the common rail (hereinafter referred to as “actual common rail pressure”) is adjusted so as to coincide with the pressure equivalent to the target fuel injection pressure (hereinafter referred to as “target common rail pressure”). However, the error of the fuel pressure signal of the pressure sensor attached to each common rail is stored in the pressure sensor individual difference storage medium and attached to the pressure sensor or the common rail. According to such a configuration, it is possible to correct the actual common rail pressure based on the error of the fuel pressure signal of the pressure sensor stored in the pressure sensor individual difference storage medium, and thus absorb only the individual difference of the injector. Compared to the above, the deviation between the actual common rail pressure and the target common rail pressure is effectively suppressed.

  According to the first aspect of the present invention, when the high-pressure fuel corresponding to the target common rail pressure set corresponding to the increase in the fuel injection pressure is injected from the injector, the injection amount can be made highly accurate. It is.

  In the second aspect of the invention, the error of the fuel pressure signal stored in the pressure sensor individual difference storage medium is caused by a plurality of high-pressure fuel conditions in which the pressure is increased to a constant pressure by an external pressure generator in the common rail. The error of the output signal detected by the pressure sensor mounted on the common rail, the error of the output signal corresponding to the lower limit fuel injection pressure and the upper limit fuel injection pressure in the pressure range of the fuel injection pressure detected by the pressure sensor. It is characterized by including.

  In this invention, in the manufacturing process before the factory shipment of the pressure accumulating fuel injection device, the fuel pressure signal of each pressure sensor is measured in the state of the pressure sensor alone or the common rail equipped with the pressure sensor, and the individual difference of the pressure sensor is measured. The fuel pressure signal error is stored as an index in a pressure sensor individual difference storage medium such as a barcode. Here, in the above manufacturing process, after the fuel pressure signal of the pressure sensor is measured after the injector and the supply device for supplying high-pressure fuel to the common rail are assembled in the accumulator fuel injection device, the common rail and injector in the subsequent process The productivity of the accumulator fuel injection device is reduced due to the relationship with the assembly process of the internal combustion engine in which the components such as the above are individually assembled to the internal combustion engine. On the other hand, when individual differences are measured with a single pressure sensor, the use conditions of the accumulator fuel injection device and measurement conditions do not match, or individual characteristics such as resistance characteristics using a sensor output inspection device are used as solid differences. Therefore, it is concerned that an error may occur when the measured individual characteristic of the pressure sensor is converted into a fuel signal.

  However, in order to measure the error of the output signal detected by the pressure sensor for each of a plurality of high-pressure fuel conditions pressurized to a constant pressure by an external pressure generator on the common rail equipped with the pressure sensor, As an error in the fuel pressure signal of the pressure sensor in a state where it is substantially mounted on the accumulator fuel injection device without assembling components other than the common rail and pressure sensor of the injection device to the common rail and pressure sensor, The error of the output signal can be measured.

  In addition, as errors in a plurality of output signals measured by changing the high-pressure fuel condition, output signals corresponding to the lower limit fuel injection pressure and the upper limit fuel injection pressure are included in the pressure range of the actual common rail pressure detected by the pressure sensor. Therefore, the actual common rail pressure can be easily corrected over the entire pressure range based on the output signals corresponding to the lower limit fuel injection pressure and the upper limit fuel injection pressure.

  Further, the lower limit injection pressure is a fuel pressure generated when a predetermined leaving condition is satisfied after the internal combustion engine is stopped, as in the third to fourth aspects of the invention.

  In this invention, the fuel pressure generated when the predetermined leaving condition after the internal combustion engine is stopped is substantially atmospheric pressure. Therefore, at such a lower limit injection pressure, the accumulator fuel injection device is assembled to the internal combustion engine. Even after the completion, the fuel pressure signal of the pressure sensor can be repeatedly measured, and the change of the fuel pressure signal, that is, the change due to deterioration over time can be measured. The actual common rail pressure can be corrected based on such a change due to deterioration over time and individual pressure sensor individual differences in the initial state, and based on the added deviation value, which is acceptable in the initial state and the state after deterioration over time. It is possible to maintain a precise injection amount accuracy.

  In particular, as described in claim 4, in the accumulator fuel injection device according to claim 3, the fuel pressure signal is detected by a pressure sensor each time a predetermined leaving condition after the internal combustion engine is stopped is repeatedly detected. It is preferable to correct the fuel pressure signal output from the pressure sensor based on the deviation between the detected fuel pressure signals.

  Here, for example, as one method of correcting the actual common rail pressure in the initial state of the internal combustion engine, the individual difference (fuel pressure signal error) of the pressure sensor stored in the pressure sensor individual difference storage medium in the initial state is predetermined. A correction method is considered in which correction is not performed when the difference is not greater than the individual difference. In such a correction method, even if the error of the fuel pressure signal of the pressure sensor (hereinafter referred to as “initial error”) is within an allowable error range in the initial state, the initial error is increased due to deterioration with time, and the error ( (Hereinafter referred to as “post-degradation error”), there is a concern that it is not possible to maintain the accuracy of the injection amount outside the allowable error range.

  On the other hand, in the invention described in claim 4, when the internal combustion engine that satisfies the predetermined neglect condition is stopped, the fuel pressure signal of the pressure sensor is repeatedly measured, and based on the fuel pressure signal in the initial state and the deviation of the fuel pressure signal. It is possible to determine whether the post-degradation error is outside the allowable error range. By performing correction based on such a determination result, it is possible to maintain an allowable injection amount accuracy.

  According to the invention described in claim 5, the fuel pressure signal output from the pressure sensor is converted into the actual common rail pressure as the fuel injection pressure, and is set according to the actual common rail pressure and the operating state of the internal combustion engine. And a control device for driving and controlling the injector based on the target injection amount to be read. The control device reads an error in the fuel pressure signal stored in the pressure sensor individual difference storage medium, and based on the error in the read fuel pressure signal. Correct the actual common rail pressure.

  In such a configuration, the actual common rail pressure converted from the fuel pressure signal output from the pressure sensor is corrected based on the error of the fuel pressure signal stored in the pressure sensor individual difference storage medium. Compared with the prior art that absorbs only the pressure sensor, the difference between the pressure sensors can be absorbed, and the deviation between the actual common rail pressure and the target common rail pressure can be effectively suppressed. Therefore, the injection amount from the injector that is injection-controlled based on the target common injection amount that is set according to the actual common rail pressure with the increased measurement accuracy and the operating state of the internal combustion engine provides high injection amount accuracy.

  According to the sixth aspect of the present invention, the fuel pressure signal output from the pressure sensor is converted into the actual common rail pressure as the fuel injection pressure, and the target common rail pressure is matched with the actual common rail pressure. And a control device that performs feedback control of the fuel discharge amount supplied from the high-pressure fuel supply source, and the control device reads an error of the fuel pressure signal stored in the pressure sensor individual difference storage medium and reads the read fuel pressure signal. The fuel discharge amount or the fuel discharge amount index value indicating the fuel discharge amount is corrected based on the error pressure of the actual common rail pressure corresponding to the error.

  In such a configuration, the actual common rail pressure converted from the fuel pressure signal output from the pressure sensor is changed to the error pressure of the actual common rail pressure corresponding to the error of the fuel pressure signal stored in the pressure sensor individual difference storage medium. The actual common rail pressure and the target common rail pressure substantially coincide with each other by the above feedback control, so that feedback control with higher accuracy than that of the conventional technology can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an overall system diagram of a pressure accumulating fuel injection apparatus to which an embodiment of the present invention is applied, and FIG. 2 is an external view showing a main part of the embodiment of the present invention. FIG. 3 shows a system for transferring specific data of a storage medium attached to the fuel pressure sensor to the ECU in a fuel pressure sensor mounted on the common rail, which is one of the manufacturing processes of the engine and the vehicle. ing.

  1 is a system that injects fuel into each cylinder of an engine (for example, a diesel engine) 100, and includes a common rail 1, an injector 2, a supply pump 3, and an engine control unit (hereinafter referred to as a control device). ECU) 4 and a drive unit (hereinafter referred to as EDU).

  The common rail 1 is a pressure accumulating container that accumulates high-pressure fuel supplied to the injector 2, and discharges from the supply pump 3 that pumps high-pressure fuel through the high-pressure pump pipe 6 so that the common rail pressure corresponding to the fuel injection pressure is accumulated. In addition to being connected to the outlet, a plurality of injector pipes 7 for supplying high pressure fuel to each injector 2 are connected.

  Between the injector pipe 7 and the common rail 1, a safety device 21 is integrally provided on the common rail 1. The safety device unit 21 is a device that shuts off the fuel supply to the injector 2 when the common rail pressure becomes excessive or when the flow rate abnormality occurs in the injector 2.

  A pressure limiter 10 is attached to a relief pipe 9 that returns fuel from the common rail 1 to the fuel tank 8. This pressure limiter 10 is a pressure safety valve, and opens when the fuel pressure in the common rail 1 exceeds the limit set pressure, and suppresses the fuel pressure in the common rail 1 to be equal to or lower than the limit set pressure.

  A pressure reducing valve 11 is attached to the common rail 1. The pressure reducing valve 11 is opened by a valve opening instruction signal given from the ECU 4 and rapidly reduces the common rail pressure via the relief pipe 9. Thus, by mounting the pressure reducing valve 11 on the common rail 1, the ECU 4 can quickly control the common rail pressure to a pressure corresponding to the vehicle running state.

  The injector 2 is mounted in each cylinder of the engine 100 and supplies fuel into each cylinder. The injector 2 is connected to the downstream ends of a plurality of injector pipes 7 branched from the common rail 1 and accumulated in the common rail 1. A fuel injection nozzle (not shown) that injects high-pressure fuel into each cylinder and an electromagnetic valve (not shown) that performs lift control of a needle housed in the fuel injection nozzle are mounted. The leaked fuel from the injector 2 is also returned to the fuel tank 8 through the relief pipe 9.

  The supply pump 3 is a high-pressure fuel pump that pumps high-pressure fuel to the common rail 1, and is equipped with a feed pump (not shown) that sucks the fuel in the fuel tank 8 into the supply pump 3 through the filter 12. The fuel sucked up by the feed pump is compressed to a high pressure and pumped to the common rail 1. The feed pump and the supply pump 3 incorporating the feed pump are driven by a common camshaft 13. The camshaft 13 is rotationally driven by the engine.

  The supply pump 3 has a mechanism for electrically controlling the discharge amount. As the mechanism, the degree of opening degree of the fuel flow path is connected to the fuel flow path for guiding the fuel into the pressurizing chamber for pressurizing the fuel to a high pressure. An intake metering valve (hereinafter referred to as SCV) 14 for adjusting the pressure is attached. The SCV 14 is a valve that adjusts the amount of fuel sucked into the pressurizing chamber and changes the discharge amount of fuel pumped to the common rail 1 by being controlled by a pump drive signal from the ECU 4. The common rail pressure is adjusted by adjusting the discharge amount of fuel to be pumped to the vehicle. That is, the ECU 4 can control the common rail pressure to a pressure corresponding to the vehicle running state by controlling the SCV 14.

  The ECU 4 is equipped with a CPU, RAM, ROM, and the like (not shown), and programs stored in the ROM and signals of sensors read into the RAM (vehicle and engine operation states detected by the signals). Various arithmetic processes are performed based on the above.

  An example of a specific calculation is as follows. For each fuel injection, the ECU 4 determines each cylinder based on a program stored in the ROM and a sensor signal (vehicle operating state) read into the RAM. The target injection amount, the injection mode, and the valve opening timing of the injector 2 are determined.

  The EDU 5 is a drive circuit that applies a valve opening drive current to the electromagnetic valve of the injector 2 based on an injector valve opening signal given from the ECU 4, and supplies high pressure fuel to the cylinder by supplying the valve opening drive current to the electromagnetic valve. The fuel injection is stopped by stopping the valve opening drive current.

  In addition to the fuel pressure sensor (hereinafter referred to as Pc sensor) 15 that detects the common rail pressure in the common rail 1, the ECU 4 includes an accelerator sensor that detects the accelerator opening (see FIG. Sensors such as a rotation speed sensor (not shown) for detecting the engine speed and a water temperature sensor (not shown) for detecting the cooling water temperature of the engine are connected.

  In addition, when the ECU 4 represents the main functions realized by executing the program stored in the memory, the injection means for controlling the injection operation of the injector 2 and the common rail pressure in the common rail 1 are set to the target fuel pressure. Common rail pressure control means for controlling to (target common rail pressure). The target common rail pressure corresponds to the fuel injection pressure injected from the injector 2 and is set to an optimum fuel pressure according to the operating state of the engine.

  The injection means includes target injection amount determination means, injection timing determination means, injection period determination means, and injector drive means. The target injection amount determining means determines an optimal target injection amount Qfin according to the engine operating state detected by various sensors. The injection timing determining means determines a command injection timing (energization pulse timing) Tfin based on the target injection amount Qfin and the engine speed Ne. The injection period determining means determines a command injection period (energization pulse time) Tinj based on the common rail pressure Pc and the target injection amount Qfin. The injector driving means applies a substantially pulsed energizing current to the injector 2 of each cylinder until the injection command pulse time (Tinj) elapses from the command injection timing (Tfin).

  The common rail pressure control means includes a discharge amount control means for controlling the discharge amount of the supply pump 3 to the common rail 1, and the actual fuel pressure in the common rail 1 (hereinafter referred to as the actual common rail pressure) is detected by the Pc sensor 15. Then, feedback control is performed so that the actual common rail pressure Pcf matches the target common rail pressure Pca.

  The discharge amount control means determines the basic drive signal to the SCV 14 based on the target common rail pressure Pca and the fuel temperature Tf and controls the supply pump 3, and controls the actual common rail pressure Pca detected by the Pc sensor 15 and the target common rail. If the pressures Pca do not match, the basic drive signal is corrected according to the difference between the actual common rail pressure Pcf and the target common rail pressure Pca, and the supply pump 3 is driven and controlled by the corrected drive signal after correction. The basic drive signal and the corrected drive signal are index values corresponding to the target discharge amount and the corrected discharge amount discharged from the supply pump, respectively, and are physical quantities for driving and controlling the SCV 14 that is the target of drive control of the ECU 4. It is.

  As described above, in the accumulator fuel injection device, the actual common rail pressure Pcf is detected by the Pc sensor 15 in the injection unit and the discharge amount control unit of the ECU 4, and the optimal injection amount and discharge amount index value (correction) is corrected based on the pressure Pcf. This is an important physical quantity in the injection control realized by the injection means and the discharge amount control means. Details of the Pc sensor 15 for detecting the actual common rail pressure Pcf and the common rail will be described later.

  Further, in a fuel injection system such as an accumulator fuel injection device, components such as the common rail 1, the injector 2, and the ECU 4 are manufactured separately in the manufacturing process of each component, and these completed components are used in the engine assembly. They are collected in the attaching process and assembled to the engine 100.

  Next, the detailed structure of the common rail 1 is demonstrated according to FIG. 1 and FIG. As shown in FIG. 1, the common rail 1 has a rail body 20 that has a substantially cylindrical shape that stores high-pressure fuel therein, and a convex safety device 21, a high-pressure pump pipe 6, and a relief pipe 9 connected to the rail body 20. For this purpose, a pipe joint part 22, a Pc sensor 15, a pressure reducing valve 11 and the like are provided.

  The Pc sensor 15 has a specific output characteristic PcVp due to individual differences as shown in the output characteristic (Pc-V characteristic) in the initial state of FIG. 5 in each finished product 15 manufactured in the manufacturing process.

  In FIG. 5, basic output characteristics of the Pc sensor 15 (for example, characteristics of a central product or a master product of the manufacturing standard) PcVs are shown by a thick solid line, and a thin solid line shows an example of each finished product 15. The subscripts “(1)” and “(2)” indicate different finished products. In the basic output characteristic PcVs and each specific output characteristic PcVp, the relationship between the common rail pressure Pc and the output voltage V is substantially linear. Each characteristic output characteristic PcVp illustrated in the figure is a schematic characteristic for easily understanding the difference from the basic output characteristic PcVs, and does not indicate actual linearity accuracy.

  Here, the inventor conducted a finished product in the manufacturing process, a continuously used market recovery product, and an endurance test on the Pc sensor 15 that detects an important physical quantity (actual common rail pressure Pcf) in carrying out the injection control. The product etc. were investigated and the knowledge about the mode of deviation of the specific output characteristic shown in the following FIG. 4 was acquired. In FIG. 4, the deviation indicates a deviation amount of the inherent output characteristic PcVp from the basic output characteristic PcVs. This deviation is not a deviation of the output voltage V but is converted from the voltage V based on the linear relationship. The deviation ΔPc of the common rail pressure Pc is shown.

  The deviation characteristic indicated by the solid line in FIG. 4 indicates the deviation ΔPc when the Pc sensor 15 is in an initial state (for example, a finished product state in the manufacturing process), and is a detection range during engine operation (hereinafter referred to as a first detection range). ) Of 20 to 200 MPa, for example, the deviation (variation) ΔPc increases as the actual common rail pressure Pcf to be detected increases. Specifically, the deviation ΔPc increases in error value to 1, 5 MPa, and 2 MPa, respectively, when the common rail pressure Pcf is 20 MPa and 200 MPa.

  Since this first detection range tends to expand due to a demand for higher fuel injection pressure, the conventional injection control method according to the conventional technique may cause a decrease in injection amount accuracy due to individual differences in the Pc sensor 15. .

  Further, the deviation characteristic indicated by a broken line in FIG. 4 indicates the deviation ΔPc in a state where the Pc sensor 15 is deteriorated with time. Compared with the deviation characteristic in the initial state, the deviation characteristic is further increased over the entire second detection range. The deviation (variation) ΔPc increases. In addition, from the results of the above-mentioned market-recovered products and durability tests that correspond to the time-degraded state, it is known that the pressure characteristics after deterioration may increase or decrease compared to the initial state depending on the use environment and use conditions. . It is difficult to predict the deviation ΔPc in such a state of deterioration with time.

  Here, in the deviation characteristic shown in FIG. 4, the common rail pressure Pc on the low pressure side outside the first detection range has an error rate of about 10% or more even in the initial state, and in particular, the low pressure state where the detected pressure Pc is 2 MPa or less. Then, since the error rate exceeds 100%, it does not make sense to calculate the actual common rail pressure Pcf itself based on the output voltage V detected by the Pc sensor 15 in the low pressure side range outside the first detection range. Absent.

  However, it has been confirmed that the linearity characteristic hardly changes in the characteristic characteristic PcVp of each Pc sensor 15 from the results of the market collection and the durability test. In other words, for example, the pressure P0 corresponding to the atmospheric pressure is detected by the Pc sensor 15, and the output voltage of the Pc sensor 15 (hereinafter referred to as the atmospheric pressure output voltage) V0, for example, the atmospheric pressure output voltage in the initial state, The deviation from the atmospheric pressure output voltage in the deteriorated state is obtained, and the specific output characteristic in the time-deteriorated state is offset by the deviation based on the deviation to compensate for the specific output characteristic in the initial state ( It can be returned).

  Here, in the detection range of the Pc sensor, the detection range including the pressure P0 corresponding to the atmospheric pressure is distinguished from the first detection range, and the detection range including the start-up preparation state (engine stop state) (hereinafter referred to as the first detection range). 2 detection range).

Therefore, the inventors configured the Pc sensor 15 and the common rail 1 as follows. That is,
An information code 71 that stores an error (deviation) of the output voltage V with respect to the basic output characteristic PcVs along with the inherent output characteristic PcVp of the Pc sensor 15 is attached to the rail body 20 of the Pc sensor 15 or the common rail 1.

  The information code 71 is a storage medium for storing information data. For example, a QR (Quick Response) code (QR code is a registered trademark of DENSO WAVE INCORPORATED) as a two-dimensional code as shown in FIG. The bar code shown in FIG. Moreover, as a method of attaching the information code 71 to the Pc sensor 15 rail body 20, a method of forming the base portion by laser marking or the like, or a method of attaching a film to which information data is transferred may be used. In this embodiment, as shown in FIG. 2A, the information code 71 is formed on the base of the Pc sensor by laser marking.

  Further, as the error peculiar to the Pc sensor 15 stored in the information code 71, as shown in the example of the Pc sensor (1) in FIG. 6, the measurement is performed under specific common rail pressure PC measurement conditions P0 and P2. Errors Δ0 and Δ2. The errors Δ0 and Δ2 are the same as those of the Pc sensor 15 or the common rail 1 provided that the pressure generating device capable of setting the measurement conditions P0 and P2 is provided. You may measure in any process of these manufacturing processes. The errors Δ0 and Δ2 of the output voltage V are also referred to as unique data.

  The pressure generator is not limited as long as it can pressurize the detection unit of the Pc sensor 15 at a constant pressure, and the pressure is not limited to the fuel pressure but may be a fluid pressure such as gas or liquid.

  When the errors Δ0 and Δ2 are measured in the manufacturing process of the Pc sensor 15, the information code 71 is attached only to the base of the Pc sensor 15.

  Here, the single Pc sensor 15 provided with the information code 71 or the common rail 1 provided with the information code 71 attached to either the Pc sensor 15 or the rail main body 20 together with the ECU 4 in the engine assembly process. In order to transfer the information data (error Δ0, Δ2) by the information code 71 to the unique ECU 4 assembled together with the engine 100, the following system is used. That is, as shown in the example of FIG. 3, the system 90 is a device that reads the information code 71 and writes it to the storage unit in the ECU 4, and includes a code reader 91 as a reading device, a controller 92, and a writing device 93. It is a well-known device provided.

  Further, the ECU 4 includes individual difference correction means for correcting the specific output characteristic PcVp due to the individual difference of the Pc sensor based on the information data (errors Δ0, Δ2) read from the information code 71. For example, in the initial state The characteristic output characteristic PcVp1 is compensated to a characteristic (hereinafter, corrected specific output characteristic) PcVp2 that substantially approximates the basic output characteristic PcVs. Further, the individual difference correcting means converges (corrects) a second individual difference in which the corrected specific output characteristic PcVp2 or the uncorrected specific output characteristic PcVp1 deteriorates to the basic output characteristic PcVs in the temporal deterioration state. Correction means are provided.

  Next, an individual difference correction method for reducing the deviation (deviation) from the basic output characteristic in the operation of the pressure-accumulation fuel injection apparatus having the above-described configuration, in particular, the individual output characteristics of the Pc sensor 15 will be described with reference to FIG. Description will be made based on FIG. 8 to 10 show the control processing in the injection control that realizes the functions of the injection means and the discharge amount control means. FIG. 8 shows the entire injection control, and FIGS. 9 and 10 show the initial state and deterioration with time. An example of each control process for absorbing individual differences of the Pc sensor 15 in the state is shown. Note that FIG. 9 corresponds to a control process performed in the initial state of the Pc sensor 15, and the control process is performed, for example, in an engine assembly process. Further, the control process in FIG. 10 corresponds to a control process performed in a time-deteriorated state of the Pc sensor 15.

  As shown in FIG. 8, in S100 (S is a step), the ECU 4 reads the unique data (errors Δ0, Δ2) of the Pc sensor 15 from the information code 71 and stores the unique data in the storage unit of the ECU 4. It is determined whether or not. When the unique data (errors Δ0, Δ2) is read and stored in the ECU 4, the process proceeds to S200, and the normal injection control is performed. When the unique data (errors Δ0, Δ2) is not stored, the determination of S100 is repeated until reading from the information code 71 and storage in the ECU 4 are performed.

  In S200, control (hereinafter referred to as individual difference absorption control) is performed to substantially approximate the inherent output characteristic PcVp (specifically, PcVp1 or PcVp2) of the Pc sensor 15 to the basic output characteristic PcVs.

  In S300, the ECU 4 converts the output voltage V into the actual common rail pressure PcF based on the characteristics recognized as being substantially approximate to the basic output characteristics PcVs in the control process of S200, and performs normal injection control. is there.

  Next, individual difference absorption control performed mainly in the initial state of the engine will be described with reference to FIG. Note that this individual difference absorption control is not limited to the initial state of the engine 100. When the Pc sensor 15 is replaced with a new one in the service factory or the like in the market, the unique data (errors Δ0, Δ2) of the new Pc sensor 15 is replaced. ) Is newly transferred to the ECU 4 and can be implemented. The individual difference absorption control shown in FIG. 9 corresponds to a control process performed in the process of FIGS. 7B and 7D in FIG. FIG. 7B shows a processing example when the unique data (error Δ0, Δ2) is larger than the set reference value (Δa1), and FIG. 7D shows a processing example when it is smaller than the set reference value (Δa1). .

  In S211, the unique data (errors Δ0 and Δ2) read from the information code 71 and stored in the storage unit in the ECU 4 is read.

  In S212, it is determined whether or not the pressure characteristic deviation ΔPc unique to the Pc sensor 15 is larger than a predetermined deviation pressure ΔPcb. The predetermined deviation pressure ΔPcb corresponds to, for example, a measurement error when repeatedly measuring at the time of detection by the Pc sensor 15. When the pressure is equal to or less than the deviation pressure ΔPcb, it can be determined that the inherent output characteristic PcVp of the Pc sensor 15 is substantially equal to the basic output characteristic PcVs.

  Specifically, in S211, the unique data (errors Δ0, Δ2) and the set reference value (Δa1) are compared to determine whether the unique output characteristic PcVp is substantially equal to the basic output characteristic PcVs. In this embodiment, for example, it is determined whether or not the error Δ2 is larger than the set reference value Δa1. If the error Δ2 inherent in the pressure sensor 15 is equal to or less than the set reference value Δa1, it is determined that the inherent output characteristic PcVp is substantially equal to the basic output characteristic PcVs, and the process proceeds to S215. Conversely, if the error Δ2 is larger than the set reference value Δa1, it is determined that the specific output characteristic PcVp needs to be corrected, and the process proceeds to S213.

  In S213, since it is determined in S211 that the specific output characteristic PcVp needs to be corrected, the initial specific output characteristic PcVp1 is offset by the upper limit error Δ2 toward the basic output characteristic PcVs as shown in FIG. 7B. The compensated characteristic PcVp2 is compensated. That is, after this processing (hereinafter referred to as initial state correction processing), the output voltage V output from the pressure sensor 15 is corrected by the offset amount Δ2, and then the corrected output voltage is output based on the basic output characteristic PcVs. Based on the relationship between V and the common rail pressure Pc, the detected actual common rail pressure Pcf is obtained.

  Thus, after the initial state correction process, the actual common rail pressure Pcf detected based on the output voltage V of the pressure sensor 15 is detected according to the corrected specific output characteristic PcVp2 substantially equal to the basic output characteristic PcVs. Therefore, it is possible to detect the actual common rail pressure Pcf with higher accuracy than in the prior art. The corrected error at the lower limit fuel pressure P0 in FIG. 7B is Δ01, and the error Δ01 is Δ01 = Δ0−Δ2.

  In S214, the correction flag fc is set to fc = 1, and it is recorded in S213 that the initial state correction process has been performed.

  In S215, since it is determined in S211 that the specific output characteristic PcVp is substantially equal to the basic output characteristic PcVs, the initial specific output characteristic PcVp1 is not corrected as shown in FIG. That is, the actual common rail pressure Pcf is obtained from the output voltage V output from the pressure sensor 15 based on the relationship between the output voltage V of the basic output characteristic PcVs and the common rail pressure Pc without performing the initial state correction process. is there.

  In S216, the correction flag fc is set to fc = 0, and it is recorded that the initial state correction process is not performed.

  Here, in the control processing of S212 and S215, when the magnitude of the error Δ2 of the specific output characteristic PcV1 of the Pc sensor 15 is equal to or smaller than the measurement error of the Pc sensor 15, the initial state correction processing is performed. Excessive correction can be prevented.

  In this embodiment, the upper limit error Δ2 of the specific data (errors Δ0, Δ2) is compared with the set reference value Δa1, but is not limited to the upper limit error Δ2, and for example, the upper limit pressure P2 of the first detection range. And an intermediate pressure between the lower limit pressure P1.

  Next, individual difference absorption control performed in the engine deterioration state with time will be described with reference to FIG. The individual difference absorption control shown in FIG. 10 corresponds to the control process performed in the process of FIGS. 7C and 7E in FIG. FIG. 7C shows a processing example on the assumption that the initial state correction processing has been performed, and FIG. 7E shows a processing example on the assumption that the initial state correction processing has not been performed. Yes.

  Here, if the engine is stopped for a predetermined period, the fuel pressure Pc in the common rail 1 decreases, and the pressure Pc becomes a constant pressure corresponding to the atmospheric pressure. Therefore, in the individual difference absorption control of FIG. 10, the output voltage V of the Pc sensor 15 is measured under the fuel pressure condition in which the pressure Pc is a constant pressure corresponding to the atmospheric pressure, and the output characteristics are corrected.

  The control process from S231 to S235 is a control process for determining whether or not a predetermined leaving condition is satisfied after the engine is stopped, and the determination is performed during the entire period of operation and stop of the engine 100.

  Specifically, in S220, the ECU 4 captures an engine parameter indicating the engine operating state. Engine parameters include engine speed Ne, accelerator opening, ignition switch (IG) ON / OFF switching signal, starter starter (STA) ON / OFF start signal, And the fuel pressure signal (output voltage V) of the pressure sensor 15 is taken in.

  In S231, it is determined whether or not IG is OFF. When IG is OFF, it can be determined that the engine 100 is stopped, so the process proceeds to S234 and the engine stop time Tstop is counted. If IG is not OFF, the process proceeds to S232.

  Here, the control processing in S232 and S233 is to determine whether or not the engine is in a stopped state. In S232, it is determined whether or not the engine 100 is stopped. In S233, the STA It is determined whether or not it is OFF. When the IG is not OFF, the engine 100 is in a state before the start preparation, a temporary stop state in which the engine 100 is temporarily stopped by idle stop control, an operating state in which the engine is operating, or the like. This is because it is assumed.

  When the engine is stopped and the STA is OFF in S232 and S233, the process proceeds to S234 and the engine stop time Tstop is counted. On the other hand, if the engine 100 is in a state other than the stop in any one of S232 and S233, or if the STA is ON, an engine operation state, a temporary stop state, or the like can be considered, and the control process ends.

  In S235, it is determined whether or not a predetermined leaving condition is satisfied after the engine is stopped. Specifically, it is determined whether the engine stop time Tstop has passed a predetermined time Ta. If the engine stop time Tstop has passed the predetermined time Ta, it is determined that the predetermined standstill condition is satisfied after the engine is stopped, and the fuel pressure condition P0 in the common rail 1 is determined to be atmospheric pressure, so the routine proceeds to S241. Then, the output determination of the Pc sensor 15 (output determination at the lower limit fuel pressure P0 corresponding to atmospheric pressure) is permitted. Conversely, if the engine stop time Tstop has not reached the predetermined time Ta, the process waits until the predetermined time Ta elapses.

  In S242, when the output determination at the lower limit fuel pressure P0 is permitted in S241, the correction flag fc is read, and it is determined whether fc = 1, that is, whether or not the initial state correction process is performed. If the initial state correction process has been performed, the process proceeds to S251. If the initial state correction process has not been performed, the process proceeds to S261.

  In S251, the characteristic output characteristic PcVp2 corrected by the initial state correction process is a characteristic deteriorated with time as shown in FIG. 7C (hereinafter referred to as a characteristic output characteristic after deterioration) PcVp3. Is calculated, and it is determined whether or not the deviation Δod is larger than the deterioration reference value Δa2. The deviation Δ0d has a relationship of Δod = Δ02−Δ01 between the error Δ02 in the inherent output characteristic PcVp3 after deterioration measured this time and the corrected error Δ02.

  When the deviation Δod is larger than the degradation reference value Δa2, the process proceeds to S252, and a correction process is performed to compensate (return) the degraded specific output characteristic PcVp3 to the specific output characteristic PcVp2. On the other hand, when the deviation Δod is equal to or less than the deterioration reference value Δa2, the control process is terminated without performing the correction process.

  As a result, the corrected specific output characteristic PcVp2 is substantially equal to the basic output characteristic PcVs in the initial state, and is maintained to be substantially equal to the basic output characteristic PcVs even in the time-degraded state. It is done.

  In S261, the inherent output characteristic PcVp1 for which the initial state correction processing has not been performed is in the degraded specific output characteristic PcVp3 as shown in FIG. 7C, so that the error Δ02 in the degraded specific output characteristic PcVp3 and the setting reference Δa1 is compared to determine whether or not the error Δ02 is larger than the set reference Δa1.

  If the error Δ02 is larger than the set reference Δa1, it is determined that the error Δ02 is larger than the measurement error of the Pc sensor 15, and the process proceeds to S262. In S262, the upper limit fuel pressure P2 and the lower limit fuel pressure P0 are offset-corrected by Δ02, so that individual difference correction that achieves the same effect as S213 is performed. Thus, for example, at the stage of market travel after shipment from the engine assembly process, the inherent output characteristic PcVp1 that has not been subjected to the initial state correction process is maintained in a state substantially equivalent to the basic output characteristic PcVs.

  Further, in S263, the correction flag fc is set to fc = 1. This is because, in the control process of S262, the initial state correction process is performed at the time when the predetermined time has elapsed, although it is not the initial state as in the engine assembly process.

  As a result, the intrinsic output characteristic PcVp1 that has been shipped from the engine assembling process and has not been subjected to the initial state correction process can be maintained in a state substantially equivalent to the basic output characteristic PcVs.

  Here, the Pc sensor 15 corresponds to the pressure sensor described in the claims, and the information code 71 corresponds to the pressure sensor individual difference storage medium described in the claims. The output voltage V corresponds to the fuel pressure signal described in the claims. Further, the second detection range is a pressure range generated in the common rail 1 during the entire operation and stop of the engine, and corresponds to the pressure range of the injection pressure described in the claims, and includes the lower limit fuel pressure P0 and the upper limit fuel. The pressure P2 corresponds to the lower limit fuel injection pressure and the upper limit fuel injection pressure described in the claims. The ECU 4 corresponds to the control device described in the claims.

  In the present embodiment described above, the accumulator fuel injector performs injection control so that the actual common rail pressure Pcf in the common rail 1 calculated based on the output voltage V of the Pc sensor 15 matches the target common rail pressure Pca. The errors Δ0 and Δ2 of the output voltage V of the Pc sensor 15 mounted on each common rail 1 are stored in the information code 71 and stored in the Pc sensor or the rail body 20 of the common rail 1. An information code 71 is provided.

  According to such a configuration, it is possible to correct the actual common rail pressure Pcf based on the error of the output voltage V of the Pc sensor 15 stored in the information code 71 and to absorb only the individual difference of the injector 2 as a result. As compared with the above, the deviation between the actual common rail pressure Pcf and the target common rail pressure Pca is effectively suppressed. As a result, when the high pressure fuel corresponding to the target common rail pressure set corresponding to the increase in the fuel injection pressure is injected from the injector 2, the injection amount can be made highly accurate.

  In the component assembled to the engine 100, the Pc sensor or the Pc sensor 15 provided with the information code 71 alone, or the information code 71 as an aspect of the component member provided with the information code 71 on the rail main body 20 of the Pc sensor or common rail 1 may be used. Any of the attached common rail 1 attached to either the Pc sensor 15 or the rail body 20 may be used.

  Here, these are assembled to the engine 100 together with the ECU 4 in the engine assembling process. However, the above-described structural member unit provided with the information code causes a decrease in productivity in the manufacturing process of the structural member, or a Pc sensor. There is a possibility that 15 individual differences may be substituted with functional characteristics other than the output voltage.

  That is, in the above manufacturing process, after assembling the injector 2, the common rail 1, and the supply pump 3 constituting the pressure accumulating fuel injection device, in the first case of measuring the output voltage V of the Pc sensor 15, the pressure sensor alone is used. A second case of measuring individual differences is conceivable. In the first case, the productivity of the pressure accumulating fuel injection device is reduced due to the relationship with the engine assembly process in which components such as the injector 2 in the subsequent process are individually assembled to the engine 100. In the second case, since individual characteristics such as resistance characteristics using a sensor output inspection device are used as the individual differences, errors Δ0 and Δ2 that are individual differences in the output voltage V of the Pc sensor 15 are directly calculated. Since measurement is not performed, when converting substitute characteristics such as resistance characteristics into specific data (errors Δ0 and Δ2) of the output voltage V, it is feared that an error occurs in the specific data. In the second case, the adjustment condition (use condition) in the accumulator fuel injection device may not be consistent with the measurement condition in the Pc sensor alone.

  On the other hand, in this embodiment, the individual difference of the Pc sensor 15 is measured not in the manufacturing process of the Pc sensor 15 but in the manufacturing process of the pressure accumulation type fuel injection device. Moreover, in the common rail 1 to which the Pc sensor 51 is assembled, a measurement condition (upper limit fuel pressure P2, lower limit fuel pressure P0) for measuring individual differences is formed by pressurizing to a constant pressure by an external pressure generator as a production facility. To do. Therefore, the Pc sensor in a state in which components other than the common rail 1 and the Pc sensor 15 in the pressure accumulation type fuel injection device are substantially mounted on the pressure accumulation type fuel injection device without being assembled to the common rail 1 and the Pc sensor 15. The errors Δ0 and Δ2 can be measured as the error of the output voltage V. Therefore, it is possible to measure the error of the output voltage V of each Pc sensor 15 with high accuracy without causing a decrease in productivity in the manufacturing process of the pressure accumulating fuel injection device.

  In addition, the measurement conditions for measuring the individual differences include the two conditions of the lower limit fuel pressure P0 and the upper limit fuel pressure P2 of the second detection range detected by the Pc sensor 15. Therefore, the lower limit fuel pressure and the upper limit fuel pressure are included. The specific output characteristic PcVp corresponding to the output voltage V corresponding to the pressure can be determined for each individual Pc sensor. Therefore, the specific output characteristic PcVp is determined by the specific data (errors Δ0, Δ2) stored in the information code 71, and based on the determined specific output characteristic PcVp, the actual common rail pressure Pcf over the entire pressure detection range. Can be easily corrected. Furthermore, in at least the first pressure detection range of the pressure detection ranges, the fuel pressure accuracy of the actual common rail pressure Pcf converted from the output voltage V of the Pc sensor 15 can be increased.

Further, in the present embodiment described above, the lower limit fuel pressure P0 is a fuel pressure generated when a predetermined leaving condition after the engine is stopped, and substantially corresponds to atmospheric pressure.
At such a lower limit injection pressure (atmospheric pressure) P0, the output voltage V of the Pc sensor 15 under the constant fuel pressure P0 is satisfied even when the accumulating fuel injection device is completely assembled to the engine 100 and the above-mentioned leaving condition is satisfied. Can be measured repeatedly, and the change (error Δ) of the output voltage V, that is, the post-degradation error Δ02 due to deterioration over time can be measured.

  The actual common rail pressure Pcf can be corrected based on the added deviation value Δ0d by taking into account the post-degradation error Δ02 due to such deterioration over time and the pressure sensor individual difference (Δ0 or Δ01) in the initial state. It is possible to maintain an acceptable injection amount accuracy in the state and the state after deterioration with time.

  Further, in the present embodiment described above, the inherent output characteristic PcVp is compensated when the magnitude of the error Δ2 that is the inherent data stored in the information code 71 is equal to or smaller than the set reference value Δa1 corresponding to the repeated measurement error. The initial state correction process is stopped. Thereby, excessive correction by performing the initial state correction process can be prevented.

  Here, the Pc sensor 15 having the specific output characteristic PcVp1 becomes the specific output characteristic PcVp3 that has deteriorated with time through the subsequent use environment and use conditions without performing the initial state correction process. That is, in such a correction method, even if the initial errors Δ0 and Δ2 of the inherent output characteristic PcVp1 of the Pc sensor 15 are within an allowable error range in the initial state, the initial error increases due to deterioration over time, and the post-degradation error Δ02. As a result, there is a concern that it is impossible to maintain the accuracy of the injection amount outside the allowable error range.

  On the other hand, in the present embodiment, every time the predetermined leaving condition after the engine stops is satisfied, the output voltage at the following fuel pressure P0 of the Pc sensor 15 is detected, and based on the deviation between the output voltages repeatedly detected. The degraded characteristic output characteristic PcVp3 of the Pc sensor 15 is compensated (returned) to the characteristic output characteristic PcVp1. As a result, the specific output characteristic PcVp1 is maintained substantially equal to the basic output characteristic PcVs even in a time-degraded state, as well as being substantially equal to the basic output characteristic PcVs in the initial state. .

  In the present embodiment described above, the ECU 4 reads the inherent data (errors Δ0, Δ2) stored in the information code 71, and substantially corrects the actual common rail pressure Pcf based on the read errors Δ0, Δ2. Yes.

  In such a configuration, the difference between the actual common rail pressure Pcf and the target common rail pressure Pca is effectively suppressed by absorbing the individual difference of the Pc sensor as compared with the conventional technique that absorbs only the individual difference of the injector 2. it can. Therefore, the injection amount from the injector 2 that is injection-controlled based on the actual common rail pressure Pcf with increased measurement accuracy and the target injection amount that is set according to the engine operating state provides high injection amount accuracy.

  Further, in the present embodiment described above, the ECU 4 substantially determines the fuel discharge amount index value (based on the error pressure of the actual common rail pressure corresponding to the errors Δ0, Δ2 of the inherent output characteristic PcVp1 of the read Pc sensor 15). The discharge amount control for correcting the correction drive signal) is performed. Thereby, it is possible to realize the discharge amount control with higher accuracy than in the prior art.

(Other embodiments)
(1) In this embodiment described above, as a configuration member unit to which the information code 71 related to the Pc sensor is attached, the common rail 1 to which the Pc sensor 15 is attached is used, and the information code 71 is attached to the base of the Pc sensor 15. . Not only this but the Pc sensor 15 single item which attached the information code | cord | chord 71, or the common rail which mounted | wore with Pc sensor 15 and another member other than this may be sufficient.

  (2) In the present embodiment described above, the unique data (error Δ0, Δ2) of the Pc sensor 15 is measured in the manufacturing process of the pressure accumulating fuel injection device. In this case, unique data (errors Δ0, Δ2) or substitute data corresponding thereto may be measured.

  (3) Further, in the present embodiment described above, the magnitude of the set reference value Δa1 to be compared with the error Δ2 that is unique data of the Pc sensor 15 is defined by the magnitude of the repeated measurement error of the Pc sensor 15. The setting reference value is not limited to this, and may be an allowable value corresponding to an allowable error of the actual common rail pressure.

1 is an overall system diagram of a pressure accumulation fuel injection device to which an embodiment of the present invention is applied. FIG. 2A is a diagram showing a storage medium provided on the common rail in FIG. 1, and FIG. 2A is an external view showing the periphery of the base of a fuel pressure sensor provided with the storage medium, FIG. 2B and FIG. c) is a schematic diagram showing an example of an aspect of a storage medium. FIG. 2 is a configuration diagram of a system that reads eigenvalue data related to an error in a fuel pressure signal stored in a storage medium attached to the fuel pressure sensor in FIG. 1 and writes it in an ECU. FIG. 2 is a diagram for explaining individual differences in output characteristics of a fuel pressure sensor in FIG. 1, and is a graph showing a pressure deviation representing a variation with respect to a reference output characteristic in an initial state and a radial deterioration state. It is the figure explaining the individual difference of the output characteristic of the fuel pressure sensor, and the standard output characteristic (the characteristic of the master product) in the relation between the common rail pressure to be detected and the output voltage, the specific output of each product manufactured in the manufacturing process It is a graph which shows an example of a characteristic. It is a graph explaining the eigenvalue data measured in a manufacturing process as a representative value of the individual difference of the output characteristic of a fuel pressure sensor. FIG. 7A is a diagram illustrating a process of absorbing individual differences based on individual eigenvalue data of the fuel pressure sensor in FIG. 6, and FIG. 7A is an example of eigenvalue data stored in a storage medium, and FIG. 7 (d) is a schematic characteristic diagram illustrating a processing example corresponding to each process in the initial state, and FIGS. 7 (c) and 7 (e) are schematic characteristic diagrams illustrating a processing example corresponding to each process in the time degradation state. is there. 2 is a flowchart showing an outline of a control method for controlling injection by an ECU in FIG. 1. It is a figure which shows an example of the control method which absorbs the individual difference of the fuel pressure sensor in FIG. 8, Comprising: It is a flowchart which shows the example of a control process which absorbs the said individual difference in an initial state. It is a figure which shows the other example of the control method which absorbs the individual difference of the fuel pressure sensor in FIG. 8, Comprising: It is a flowchart which shows the example of control processing which absorbs the said individual difference in a time-dependent deterioration state.

Explanation of symbols

1 common rail 2 injector 3 supply pump 4 ECU (control means, control device, engine control unit)
5 EDU (drive unit)
11 Pressure reducing valve 14 SCV (Suction metering valve)
15 Pc sensor (pressure sensor)
20 rail body 21 safety device 71 information code (storage medium)
90 Writing System 91 Code Reader 92 Controller 93 Writing Device 100 Engine

Claims (6)

In an accumulator fuel injection device that accumulates high-pressure fuel corresponding to the fuel injection pressure in a common rail and distributes the high-pressure fuel accumulated in the common rail to injectors mounted in each cylinder of the internal combustion engine.
A pressure sensor provided on the common rail and outputting a fuel pressure signal corresponding to the fuel injection pressure;
A pressure sensor individual difference storage medium storing an error of the fuel pressure signal of the pressure sensor,
The pressure accumulation type fuel injection device, wherein the pressure sensor individual difference storage medium is attached to the pressure sensor or the common rail. The error of the fuel pressure signal stored in the pressure sensor individual difference storage medium is:
An error of an output signal detected by the pressure sensor mounted on the common rail under a plurality of high-pressure fuel conditions pressurized to a constant pressure by an external pressure generator in the common rail,
The pressure accumulation type fuel injection device according to claim 1, wherein the pressure range of the fuel injection pressure detected by the pressure sensor includes an error of an output signal corresponding to a lower limit fuel injection pressure and an upper limit fuel injection pressure.   The pressure-accumulation fuel injection device according to claim 2, wherein the lower limit injection pressure is a fuel pressure generated when a predetermined leaving condition after the internal combustion engine is stopped is satisfied. The pressure accumulation type fuel injection device according to claim 3,
Every time a predetermined leaving condition after the internal combustion engine is stopped is satisfied, a fuel pressure signal is detected by the pressure sensor,
An accumulator fuel injection device that corrects a fuel pressure signal output from the pressure sensor based on a deviation between the fuel pressure signals repeatedly detected. The fuel pressure signal output from the pressure sensor is converted into an actual common rail pressure as an injection pressure of the fuel, and based on the actual common rail pressure and a target injection amount set according to the operating state of the internal combustion engine. A control device for driving and controlling the injector,
The control device reads an error of the fuel pressure signal stored in the pressure sensor individual difference storage medium, and corrects the actual common rail pressure based on the error of the read fuel pressure signal. The accumulator fuel injection device according to any one of claims 1 to 4. A fuel pressure signal output from the pressure sensor is converted into an actual common rail pressure as an injection pressure of the fuel, and fuel supplied from a high pressure fuel supply source so as to coincide with a target common rail pressure based on the actual common rail pressure A control device for feedback control of the discharge amount,
The control device reads an error of the fuel pressure signal stored in the pressure sensor individual difference storage medium, and determines a fuel discharge amount or a fuel based on an error pressure of the actual common rail pressure corresponding to the error of the read fuel pressure signal. The pressure accumulation type fuel injection device according to any one of claims 1 to 5, wherein a fuel discharge amount index value indicating a discharge amount is corrected.

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