Evaluation Device, Evaluation System, Evaluation Method, and Program

Abstract

Provided is a method for simply evaluating individual differences in injection response delay times of fuel injection valves that supply fuel to an engine. 【Solution means】The measuring device is a measuring device that evaluates the injection response delay time from when an opening command is instructed to the fuel injection valve provided in the fuel supply system until fuel is injected from the fuel injection valve, and is a means for acquiring a measured value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by fuel being injected from the fuel injection valve, a means for measuring the response time from when the opening command is instructed until the measured value changes, and by calculating the difference between a predetermined first said response time as a reference and a second said response time measured for the fuel injection valve to be evaluated, a means for evaluating the individual difference in the injection response delay time of the fuel injection valve to be evaluated.

Description

Technical Field

[0001] The present disclosure relates to an evaluation device, an evaluation system, an evaluation method, and a program for a fuel injection device.

Background Art

[0002] In an engine (for example, a diesel engine) that injects fuel into a cylinder and causes self-ignition, it is necessary to precisely control the timing at which fuel is actually injected from the fuel injection valve from the viewpoints of engine performance, vibration, emissions, durability, etc. Also, in a general fuel injection valve, there is a response delay from when an energization signal for injection is applied until the valve element actually lifts and injection starts. This response delay time has individual differences due to tolerances of each part of the injection valve. Therefore, in order to precisely control the fuel injection timing, it is necessary to grasp this individual difference. For example, in Patent Document 1, before assembling a fuel injection valve into an internal combustion engine, the fuel injection valve is preliminarily classified into one of a plurality of grades regarding injection response delay characteristics, and based on the classified grade, the reference fuel injection timing is corrected to control the injection timing in a spark ignition type multi-cylinder internal combustion engine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, a method for evaluating the individual differences in the injection response delay time of a fuel injection valve is required. For example, in order to grasp the injection response delay time of a fuel injection valve, a method of measuring the flow rate per unit time (injection rate) of fuel injected from each individual of the fuel injection valve is provided. However, this measurement requires a dedicated measuring device, the equipment configuration becomes complicated, and the equipment investment amount increases.

[0005] The present disclosure provides an evaluation device, an evaluation system, an evaluation method, and a program that can solve the above problems.

Means for Solving the Problems

[0006] The evaluation device of the present disclosure is a measurement device for evaluating the injection response delay time from when an open command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, Individual differences comprising means for acquiring a measurement value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by fuel being injected from the fuel injection valve, means for measuring the response time from when the open command is instructed until the measurement value changes, and means for evaluating the individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating the difference between a predetermined first said response time serving as a reference and a second said response time measured for the fuel injection valve to be evaluated. means for outputting the difference as a compensation value for compensating for individual differences in the injection response delay time set in the control device of the fuel injection valve to be evaluated; It is provided with.

[0007] The evaluation system of the present disclosure includes a fuel supply system including a fuel injection valve that injects fuel, a control device that controls the fuel injection valve, a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by fuel being injected from the fuel injection valve, the above-mentioned and an evaluation device. When the evaluation of individual differences in the injection response delay time is completed, the fuel injection valve is removed from the fuel supply system.

[0008] The evaluation method of the present disclosure is an evaluation method for evaluating the injection response delay time from when an open command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, Individual differences comprising the steps of acquiring a measurement value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by fuel being injected from the fuel injection valve, measuring the response time from when the open command is instructed until the measurement value changes, and evaluating the individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating the difference between a predetermined first said response time serving as a reference and a second said response time measured for the fuel injection valve to be evaluated.step of outputting the difference as a compensation value for compensating for individual differences in the injection response delay time set in the control device of the fuel injection valve to be evaluated; has

[0009] The program of the present disclosure causes a computer to evaluate an injection response delay time from when an opening command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, Individual differences the method including: obtaining a measurement value of a sensor that detects a change in state of the fuel supply system or the fuel injection valve caused by injection of fuel from the fuel injection valve; measuring a response time from when the opening command is instructed until the measurement value changes; and evaluating an individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating a difference between a predetermined first one of the response times as a reference and a second one of the response times measured for the fuel injection valve to be evaluated. step of outputting the difference as a compensation value for compensating for individual differences in the injection response delay time set in the control device of the fuel injection valve to be evaluated; Execute a process having

Advantages of the Invention

[0010] According to the above-described evaluation apparatus, evaluation system, evaluation method, and program, an individual difference in the injection response delay time of a fuel injection valve can be easily evaluated.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0012] <First Embodiment> Hereinafter, a method for evaluating individual differences in the injection response delay time of the fuel injection valve according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic configuration diagram of an evaluation system according to the first embodiment. The evaluation system 100 includes a fuel supply system 10, a measuring device 20 for measuring the injection response delay time of the fuel injection valve 4, a control device 30 for controlling the fuel supply system 10, and a pressure sensor 6 for detecting a change in the state of the fuel supply system 10. The fuel supply system 10 includes a fuel tank 1, a high-pressure pump 2, an accumulator 3, a fuel injection valve 4, and a pipe 5 connecting these. The fuel in the fuel tank 1 is pressurized by the high-pressure pump 2, and the fuel at high pressure is sent to the accumulator 3 through the pipe 5. The high-pressure fuel stored in the accumulator 3 is injected from the fuel injection valve 4. The control device 30 controls the opening and closing of the fuel injection valve 4. When the control device 30 opens the fuel injection valve 4, fuel is injected. In engines that perform diffusion combustion, such as represented by diesel engines, or engines that include partially premixed combustion in addition to diffusion combustion, fuel and air mixed at a certain ratio burn by self-ignition when they reach a certain temperature. In the control of such engines, compared with engines that perform complete premixed combustion or forced ignition, it is necessary to control the timing at which fuel is actually injected from the fuel injection valve with high precision. Although there is a certain response delay from when the control device 30 issues an opening command to the fuel injection valve 4 until fuel is actually injected, there are individual differences in the fuel injection valve 4, and the time of this response delay also varies for each fuel injection valve 4. If the opening command for the fuel injection valve 4 is not issued according to the injection response delay for each fuel injection valve 4 with individual differences, it is impossible to perform desired combustion control. Therefore, in the evaluation system 100 of the present embodiment, a pressure sensor 6 is installed upstream in the fuel supply system 10 of the fuel injection valve 4 before shipment, and the injection response delay time of the fuel injection valve 4 is evaluated by analyzing the measurement result of the pressure sensor 6 with the measuring device 20. The measuring device 20 calculates the difference between the measured injection response delay time and a reference injection response delay time. For example, as the reference injection response delay time, an average value of the injection response delay times of a plurality of fuel injection valves 4 measured using the evaluation system 100 may be set. This time difference serves as a compensation value for compensating for individual differences in the injection response delay time.At the time of shipment, the fuel injection valve 4 is removed from the evaluation system 100 and shipped with the fuel injection valve 4 associated with the compensation value. After shipment, the fuel injection valve 4 is mounted on the fuel supply system of the engine, and the compensation value associated with the fuel injection valve 4 is set in the control device of the engine.

[0013] The pressure sensor 6 is installed between the accumulator 3 and the fuel injection valve 4 in the pipe 5 and measures the pressure in the pipe 5. Next, as described with reference to FIG. 2, in the present embodiment, the injection response delay time is measured by paying attention to the time-series pressure change caused by the fuel being injected from the fuel injection valve 4. This pressure change propagates in the direction opposite to the fuel flow direction, from the fuel injection valve 4 toward the accumulator 3. In order to accurately evaluate the individual differences of the fuel injection valves 4, it is desirable that the pressure sensor 6 be installed as close as possible to the fuel injection valve 4.

[0014] The measuring device 20 includes an acquisition unit 21, an evaluation unit 22, an output unit 23, and a storage unit 24. The acquisition unit 21 acquires the pressure measured by the pressure sensor 6 and records the acquired pressure and the acquisition time thereof in the storage unit 24 in association with each other. The evaluation unit 22 measures the injection response delay time of the fuel injection valve 4 and calculates a compensation value for compensating for the individual differences in the injection response delay time. The output unit 23 outputs a compensation value for compensating for the individual differences in the injection response delay time for each fuel injection valve 4. The storage unit 24 stores the time-series pressure measured by the pressure sensor 6.

[0015] FIG. 2 is a diagram for explaining a method for evaluating the injection response delay time according to the first embodiment. FIGS. 2(a) to 2(d) schematically show the energization waveform of the fuel injection valve 4, the injection rate of the fuel injected from the fuel injection valve 4, the internal pressure of the fuel injection valve 4, and the time-series data of the pressure detected by the pressure sensor 6, respectively. The same positions on the horizontal axes of FIGS. 2(a) to 2(d) represent the same time.

[0016] The vertical axis of Fig. 2(a) represents current, and the horizontal axis represents time. The current is the current of the opening command (energization signal) output by the control device 30 to the fuel injection valve 4. Graph 200 shows the transition of the energization signal. When the current value of the command signal exceeds a predetermined value, it becomes an opening command to the fuel injection valve 4. In the case of Fig. 2(a), an opening command to the fuel injection valve 4 is output at time t0.

[0017] The vertical axis of Fig. 2(b) represents injection rate, and the horizontal axis represents time. Graphs 201 to 203 show the transition of the injection rate. Graph 201 shows the transition of the injection rate of a certain fuel injection valve 4 (referred to as individual A). Graph 202 shows the transition of the injection rate of a fuel injection valve 4 different from individual A (referred to as individual B). Graph 203 shows the transition of the injection rate of a fuel injection valve 4 different from individuals A and B (referred to as individual C). These graphs can be obtained, for example, by measuring the injection rate with dedicated equipment. The injection rate of individual A exceeds 0 at time t1. Since the fuel injection command was output at time t0, the injection response delay time of individual A is t1 - t0. The injection rate of individual B exceeds 0 at time t2. The injection response delay time of individual B is t2 - t0. The injection rate of individual C exceeds 0 at time t3. The injection response delay time of individual C is t3 - t0.

[0018] The vertical axis of Fig. 2(c) represents the pressure in the fuel injection valve 4, and the horizontal axis represents time. Graphs 204 to 206 show the transition of the pressure of individuals A to C, respectively. These graphs can be obtained, for example, by providing a pressure sensor in the fuel injection valve 4 to measure the pressure. When an energization signal is applied to the fuel injection valve 4 and the valve body lifts to start injection, high-pressure fuel is discharged, causing the pressure inside the fuel injection valve 4 to decrease, and this pressure decrease propagates upstream in the fuel supply system 10. As shown in graph 204, the pressure of individual A starts to decrease at time t1. Similarly, referring to graphs 205 and 206, the pressure decreases of individuals B and C start at times t2 and t3, respectively. That is, the injection response delays of individuals A to C can also be measured by monitoring the pressure fluctuations (decreases) of individuals A to C.

[0019] The vertical axis of Fig. 2(d) represents the pressure measured by the pressure sensor 6, and the horizontal axis represents time. Graphs 207 to 209 show the changes in the pressure measured by the pressure sensors 6 installed on the upstream sides of individuals A to C, respectively. The delay time from the application of the energization signal to the fuel injection valve 4 until the pressure sensor 6 detects a pressure drop is the sum of the injection response delay time and the time for the pressure drop generated by the fuel injection valve 4 to propagate to the pressure sensor 6. The time for the pressure drop generated by the fuel injection valve 4 to propagate to the pressure sensor 6 depends on the distance in the fuel supply system 10 from the injection holes of the fuel injection valve 4 to the pressure sensor 6 and the speed of sound in the fuel. Here, since the pressure sensor 6 is installed at the same position for any of individuals A to C, the time for the pressure drop generated in each of individuals A to C to propagate to the pressure sensor 6 is the same for individuals A to C. Therefore, the time from the application of the energization signal to the fuel injection valve 4 until the pressure sensor 6 detects a pressure drop and the injection response delay time have a high correlation, and the time difference from when the energization signal is output to individuals A to C until the pressure sensor 6 detects a pressure drop is the individual difference in the injection response delay time of individuals A to C.

[0020] By comparing the time from the application of the energization signal to the fuel injection valve 4 until the pressure sensor 6 detects a pressure drop between the fuel injection valve 4 to be evaluated and the reference fuel injection valve 4, the time difference (individual difference) from the reference injection response delay time can be calculated with an accuracy comparable to that when measuring the flow rate per unit time (injection rate) of the fuel injected from each individual of the fuel injection valve 4 using a dedicated measuring device. Also, by compensating the injection timing for the reference fuel injection valve 4 with the calculated time difference, fuel injection can be realized at a timing corresponding to the injection response delay time of each individual.

[0021] (Operation) Fig. 3A is a first flowchart showing an example of the evaluation process for the injection response delay time according to the first embodiment. The acquisition unit 21 acquires time-series pressure measurement values of one or more reference fuel injection valves 4 (for example, individual A or a plurality of fuel injection valves 4) (step S1). The acquisition unit 21 acquires the time-series pressure measurement values measured by the pressure sensor 6 when an energization signal is applied from the control device 30 to the reference fuel injection valve 4, and records them in the storage unit 24. Next, the acquisition unit 21 acquires time-series pressure measurement values of the fuel injection valve 4 to be evaluated (for example, individual B or individual C) (step S2). The acquisition unit 21 acquires the time-series pressure measurement values measured by the pressure sensor 6 when an energization signal is applied from the control device 30 to the fuel injection valve 4 to be evaluated, and records them in the storage unit 24. Next, the evaluation unit 22 calculates a compensation value for the injection response delay time (step S3). The evaluation unit 22 reads out the time-series pressure measurement values of the reference fuel injection valve 4 from the storage unit 24, and calculates the time from when the energization signal is applied until the pressure drop is measured. When there are a plurality of reference fuel injection valves 4, the evaluation unit 22 calculates the average value (it may also be the median or the mode) of the time from when the energization signal is applied to when the pressure drop is measured for the plurality of fuel injection valves 4. This time is defined as time T1. Further, the evaluation unit 22 reads out the time-series pressure measurement values of the fuel injection valve 4 to be evaluated from the storage unit 24, and calculates the time from when the energization signal is applied until the pressure drop is measured. This time is defined as time T2. The evaluation unit 22 calculates the difference between time T2 and time T1. This time difference is the compensation value for the injection response delay time. Next, the output unit 23 outputs the compensation value to a display device or the like that outputs it (step S4). The shipping engineer sets the output compensation value in the engine control device on which the fuel injection valve 4 to be evaluated is mounted after shipment. For example, this engine control device is designed and implemented to apply an energization signal to the fuel injection valve 4 in consideration of a reference injection response delay time T1 in the initial state. When time T2 > time T1, the engineer sets it so that the energization signal is applied to the fuel injection valve 4 earlier by the amount of the compensation value (time T2 - time T1). As a result, the fuel injection valve 4 having the injection response delay time T2 can also inject fuel at a desired timing. Note that the setting of the compensation value in the control device may be configured to be performed automatically.

[0022] In FIG. 3A, the processing flow in combination with the description of FIG. 2 was described. As another processing flow, the injection response delay times (specifically, the time from the application of the energization signal to the detection of the pressure drop) of a plurality of fuel injection valves 4 are measured in advance using the evaluation system 100, and the average value or the like is set in the measurement device 20 in advance as the reference injection response delay time, and the injection response delay time of the fuel injection valve 4 to be evaluated is measured using the evaluation system 100. An example of specific processing is shown in FIG. 3B. FIG. 3B is a second flowchart showing an example of the evaluation process of the injection response delay time according to the first embodiment. The same processes as those in FIG. 3A are denoted by the same reference numerals, and the description thereof is omitted. On the premise that, for a plurality of fuel injection valves 4, the time from the application of the energization signal to the measurement of the pressure drop is measured in advance, and the average value or the like is registered in the storage unit 24 as the reference injection response delay time. First, the acquisition unit 21 acquires a reference injection response delay time from the storage unit 24 (step S1´). Next, the acquisition unit 21 acquires time-series pressure measurement values of the fuel injection valve 4 to be evaluated (step S2). Next, the evaluation unit 22 calculates a compensation value for the injection response delay time (step S3´). Let the reference injection response delay time acquired in step S1´ be time T1. The evaluation unit 22 reads out the time-series pressure measurement values of the fuel injection valve 4 to be evaluated from the storage unit 24, and calculates the time from when the energization signal is applied until the pressure drop is measured. Let this time be time T2. The evaluation unit 22 calculates the difference between time T2 and time T1. This time difference is the compensation value for the injection response delay time. Next, the output unit 23 outputs the compensation value to a display device or the like for output (step S4). Note that in FIG. 3A, the processing order of steps S1 and S2 may be reversed. Similarly, in FIG. 3B, the processing order of steps S1´ and S2 may be reversed.

[0023] (Effect) As described above, in the present embodiment, when fuel injection starts, the pressure drop propagating inside the fuel supply system 10 starting from the fuel injection valve 4 is detected by the pressure sensor 6 installed upstream of the fuel injection valve 4, and based on the time from when the energization signal is applied to the fuel injection valve 4 until the pressure sensor 6 detects the pressure drop, the injection response delay time of each individual is grasped and compensated. Thereby, when grasping the injection response delay time of each individual during the shipping operation of the fuel injection valve 4, compared with the case of measuring the flow rate (injection rate) per unit time of the fuel injected from each individual using a dedicated measuring device, it is possible to evaluate the individual differences in the injection response delay time with the same degree of accuracy with a simple equipment configuration.

[0024] In the above description, the time difference between the average time T1 from the application of the energization signal measured for a plurality of reference fuel injection valves 4 to the detection of the pressure drop and the time T2 from the application of the energization signal measured for the fuel injection valve 4 to be evaluated to the detection of the pressure drop is used as the compensation value. However, by utilizing the fact that the time for the pressure drop to propagate to the pressure sensor 6 depends on the distance and the speed of sound, the time for the pressure drop to propagate from the fuel injection valve 4 to the pressure sensor 6 is calculated (length within the fuel supply system 10 from the fuel injection valve 4 to the pressure sensor 6 ÷ speed of sound), and the calculated time is subtracted from the time T2, whereby the injection response delay time of the fuel injection valve 4 to be evaluated may be calculated. By calculating the injection response delay time for each individual and calculating the difference from the injection response delay time of the reference fuel injection valve 4 calculated in the same manner, a compensation value can be obtained.

[0025] <Second Embodiment> Hereinafter, the evaluation system 100a according to the second embodiment of the present invention will be described with reference to FIG. 4. FIG. 4 is a schematic configuration diagram of the evaluation system according to the second embodiment. The evaluation system 100a includes a strain gauge 7 that detects a change in the state of the surface of the fuel supply system 10 instead of the pressure sensor 6. Other configurations are the same as those in the first embodiment. In the evaluation system 100a of the second embodiment, the strain gauge 7 is installed upstream of the fuel injection valve 4 in the fuel supply system 10 before shipment, and the measurement result of the strain gauge 7 is analyzed by the measuring device 20 to evaluate the injection response delay time of the fuel injection valve 4.

[0026] The strain gauge 7 is installed on the surface of the pipe 5 between the accumulator 3 and the fuel injection valve 4. For the reasons described in the first embodiment, it is desirable that the strain gauge 7 be installed as close as possible to the fuel injection valve 4.

[0027] As described in the first embodiment, with the start of fuel injection, a pressure drop propagates inside the fuel supply system 10 starting from the fuel injection valve 4. In the second embodiment, a strain gauge 7 attached to the surface of the fuel supply system 10 detects a change in the amount of strain of components (such as the pipe 5) that make up the fuel supply system 10 due to the pressure drop inside the fuel supply system 10, and regards the time from the application of the energization signal to the measurement of the change in the amount of strain due to the pressure drop as the sum of the injection response delay time and the propagation time of the pressure drop, and evaluates the difference between the time T3 measured for the reference fuel injection valve 4 and the time T4 measured for the fuel injection valve 4 to be evaluated as the individual difference in the injection response delay time.

[0028] (Operation) The process of evaluating the individual differences in the injection response delay time of the fuel injection valve in the second embodiment is the same as the process described in the first embodiment with reference to FIG. 3, except that the measurement target is changed from the pressure drop to the strain amount change. That is, the acquisition unit 21 acquires the time-series strain amount measurement values of one or more reference fuel injection valves 4 (for example, individual A) and records them in the storage unit 24 (corresponding to step S1 in FIG. 3A). Alternatively, in the storage unit 24, a reference injection response delay time (accurately, the time from the application of the energization signal until a strain amount change of a predetermined value or more is first measured) calculated based on the time-series strain amounts measured for a plurality of fuel injection valves 4 is registered, and the acquisition unit 21 reads and acquires this reference injection response delay time from the storage unit 24 (corresponding to step S1' in FIG. 3B). Next, the acquisition unit 21 acquires the time-series strain amount measurement values of the fuel injection valve 4 to be evaluated (for example, individual B, etc.) and records them in the storage unit 24 (corresponding to step S2 in FIGS. 3A and 3B). Next, the evaluation unit 22 calculates a compensation value for the injection response delay time (corresponding to step S3 in FIG. 3A and step S3' in FIG. 3B). The evaluation unit 22 reads the time-series strain amount measurement values of the reference fuel injection valve 4 from the storage unit 24 and calculates the time T3 from the application of the energization signal until a strain amount change of a predetermined value or more is first measured (step S3 in FIG. 3A). Alternatively, the evaluation unit 22 sets the reference injection response delay time registered in the storage unit 24 in advance as the time T3 (step S3' in FIG. 3B). Further, the evaluation unit 22 reads the time-series strain amount measurement values of the fuel injection valve 4 to be evaluated from the storage unit 24 and calculates the time T4 from the application of the energization signal until a strain amount change of a predetermined value or more is first measured. The evaluation unit 22 calculates the difference between the time T4 and the time T3 as the compensation value for the injection response delay time. Next, the output unit 23 outputs the compensation value to a display device or the like for output (corresponding to step S4 in FIGS. 3A and 3B). The output compensation value is set in the control device of the engine in which the fuel injection valve 4 to be evaluated is mounted.

[0029] (Effect) According to the second embodiment, by attaching the strain gauge 7 to the surface of the components of the fuel supply system 10, it is possible to more simply evaluate the injection response delay time of each individual fuel injection valve compared to the case where the pressure sensor 6 is installed. Also, in the second embodiment, by utilizing the fact that the time for the pressure drop to propagate to the attachment position of the strain gauge 7 depends on the distance and the speed of sound, the injection response delay time of the fuel injection valve 4 to be evaluated is calculated, and the difference from the injection response delay time of one or more fuel injection valves 4 serving as a reference calculated in the same manner (in the case of a plurality, the average value of the injection response delay times of the fuel injection valves 4) is calculated to calculate the compensation value.

[0030] <Third Embodiment> Hereinafter, the evaluation system 100b according to the third embodiment of the present invention will be described with reference to FIGS. 5 to 6. FIG. 5 is a schematic configuration diagram of the evaluation system according to the third embodiment. The evaluation system 100b includes a vibration sensor 8 instead of the pressure sensor 6 of the first embodiment. Other configurations are the same as those of the first embodiment. In the evaluation system 100b of the third embodiment, the vibration sensor 8 is installed near the fuel injection valve 4 of the fuel supply system 10 before shipment, and the injection response delay time of the fuel injection valve 4 is evaluated by analyzing the measurement result of the vibration sensor 8 with the measuring device 20.

[0031] The vibration sensor 8 is installed near the fuel injection valve 4. Instead of detecting the pressure drop inside the fuel supply system 10 accompanying fuel injection as in the first and second embodiments, the vibration sensor 8 measures the rise of the vibration generated by the valve body colliding with other components (stoppers) inside the fuel injection valve 4 when the fuel injection valve 4 opens. The vibration sensor 8 is provided, for example, near the movable range of the valve body of the fuel injection valve 4 main body so that this vibration can be detected well.

[0032] FIG. 6 is a diagram for explaining the method of measuring the injection response delay time according to the third embodiment. Figs. 6(a) to 6(c) schematically show the energization waveform of the fuel injection valve 4, the injection rate of the fuel injected from the fuel injection valve 4, and the time series data of the acceleration due to the vibration of the fuel injection valve 4, respectively. The same positions on the horizontal axes of Figs. 6(a) to 6(c) represent the same time.

[0033] The vertical axis of Fig. 6(a) indicates the current of the energization signal, and the horizontal axis indicates the time. Graph 600 shows the transition of the energization signal. In the case of Fig. 6(a), an opening command to the fuel injection valve 4 is applied at time t0.

[0034] The vertical axis of Fig. 6(b) indicates the injection rate, and the horizontal axis indicates the time. Graph 601 shows the transition of the injection rate. The injection rate of the fuel injection valve 4 exceeds 0 at time t1. Since the fuel injection command was output at time t0, the injection response delay time of the fuel injection valve 4 is t1 - t0.

[0035] The vertical axis of Fig. 6(c) indicates the acceleration measured by the vibration sensor 8, and the horizontal axis indicates the time. Graph 602 shows the transition of the acceleration measured by the vibration sensor 8 installed in the fuel injection valve 4. The time from the application of the energization signal to the fuel injection valve 4 until the vibration sensor 8 detects the rise of the vibration is t2 - t0. Since the rise of the vibration measured by the vibration sensor 8 is considered to be associated with the opening of the control valve inside the fuel injection valve 4, there is considered to be a correlation between the rise of the injection rate in Fig. 6(b) and the rise of the vibration in Fig. 6(c). That is, there is considered to be a certain relationship between t2 - t0 and t1 - t0.

[0036] Therefore, by comparing the time from the application of the energization signal to the fuel injection valve 4 until the vibration sensor 8 detects the vibration between the fuel injection valve 4 to be evaluated and the reference fuel injection valve 4, the time difference of the injection response delay time of each individual fuel injection valve 4 can be calculated. Also, by compensating the injection timing with respect to the reference fuel injection valve 4 by the calculated time difference, fuel injection can be realized at a timing corresponding to the injection response delay time of each individual.

[0037] (Operation) The process of evaluating the individual differences in the injection response delay time of the fuel injection valve in the third embodiment is the same as the process described in the first embodiment with reference to FIG. 3, except that the measurement target is changed from pressure drop to vibration acceleration. That is, the acquisition unit 21 acquires the time-series acceleration measurement values of the reference fuel injection valve 4 and records them in the storage unit 24 (corresponding to step S1 in FIG. 3A). Alternatively, the storage unit 24 stores in advance the reference injection response delay time (accurately, the time from when the energization signal is applied until the first rise in acceleration is measured) calculated based on the time-series acceleration measurement values measured for a plurality of fuel injection valves 4. The acquisition unit 21 reads and acquires this reference injection response delay time from the storage unit 24 (corresponding to step S1' in FIG. 3B). Next, the acquisition unit 21 acquires the time-series acceleration measurement values of the fuel injection valve 4 to be evaluated and records them in the storage unit 24 (corresponding to step S2 in FIGS. 3A and 3B). Next, the evaluation unit 22 calculates a compensation value for the injection response delay time (corresponding to step S3 in FIG. 3A and step S3' in FIG. 3B). The evaluation unit 22 reads the time-series acceleration measurement values of the reference fuel injection valve 4 from the storage unit 24 and calculates the time T5 from when the energization signal is applied until the first rise in acceleration is measured. Alternatively, the evaluation unit 22 reads the reference injection response delay time from the storage unit 24 and sets this time as time T5. Also, the evaluation unit 22 reads the time-series acceleration measurement values of the fuel injection valve 4 to be evaluated from the storage unit 24 and calculates the time T6 from when the energization signal is applied until the first rise in acceleration is measured. The evaluation unit 22 calculates the difference between time T6 and time T5 as the compensation value for the injection response delay time. Next, the output unit 23 outputs the compensation value to a display device or the like for output (corresponding to step S4 in FIG. 3). The output compensation value is set in the control device of the engine in which the fuel injection valve 4 to be evaluated is installed.

[0038] (Effect) According to the third embodiment, even when it is difficult to arrange the pressure sensor 6 and the strain gauge 7 in the fuel supply system 10, it is possible to simply evaluate the injection response delay time of each individual fuel injection valve. In the above-described embodiment, the first rise of the vibration was detected. However, the second or third rise of the vibration may be detected, and a compensation value may be calculated based on the reference injection response delay time (exactly, the time from when the energization signal is applied until the rise of the second or third vibration is measured) and the time difference until the rise of the vibration of the individual to be evaluated. Further, when detecting the first rise, the time from when the energization signal is applied until the rise of the first vibration is measured for the fuel injection valve 4 to be evaluated may be regarded as the injection response delay time (instead of the time from when the energization signal is applied until the fuel is actually injected). In this case, the compensation value may be calculated by calculating the difference from the injection response delay time of one or a plurality of reference fuel injection valves 4 calculated in the same manner (in the case of a plurality, the average value of the injection response delay times of the fuel injection valves 4).

[0039] FIG. 7 is a schematic block diagram showing the hardware configuration of the evaluation system according to the embodiment. The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. Each of the above-described measuring device 20 and control device 30 is implemented in a separate computer 90. The operations of the above-described respective processing units are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93 and expands it in the main memory 92, and executes the above processing according to the program. Further, the processor 91 secures a storage area corresponding to each of the above-described storage units in the main memory 92 according to the program. Examples of the processor 91 include a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), a microprocessor, and the like.

[0040] The program may be for realizing a part of the functions to be exerted by the computer 90. For example, the program may exert functions by combination with other programs already stored in the storage or combination with other programs implemented in other devices. In other embodiments, the computer 90 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, part or all of the functions realized by the processor 91 may be realized by the integrated circuit. Such an integrated circuit is also included as an example of a processor.

[0041] Examples of the storage 93 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), a semiconductor memory, and the like. The storage 93 may be an internal medium directly connected to the bus of the computer 90, or may be an external medium connected to the computer 90 via the interface 94 or a communication line. Further, when this program is distributed to the computer 90 via a communication line, the computer 90 that has received the distribution may expand the program in the main memory 92 and execute the above processing. In at least one embodiment, the storage 93 is a non-transitory tangible storage medium. Also, the program may be for realizing a part of the above-described functions. Furthermore, the program may be a so-called difference file (difference program) that realizes the above-described functions in combination with other programs already stored in the storage 93.

[0042] As described above, some embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and its equivalent scope. For example, the first to third embodiments may be arbitrarily combined. For example, when combining the first embodiment and the second embodiment, both a pressure sensor 6 and a strain gauge 7 are provided in the fuel supply system 10, and an average value of the compensation value calculated by the method of the first embodiment and the compensation value calculated by the method of the second embodiment may be used as the compensation value. Further, for example, when combining the first to third embodiments, both a pressure sensor 6 and a strain gauge 7 are provided in the fuel supply system 10, a vibration sensor 8 is provided in the fuel injection valve 4, and an average value of the compensation values calculated by the methods of the first to third embodiments may be used as the compensation value. The same applies to other combinations.

[0043] <Appendix> The evaluation device, evaluation system, evaluation method, and program described in each embodiment are understood as follows, for example.

[0044] (1) The evaluation device according to the first aspect is an evaluation device that evaluates the injection response delay time from when an opening command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, and includes means for acquiring a measured value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by the injection of fuel from the fuel injection valve, means for measuring a response time from when the opening command is instructed until the measured value changes, and means for evaluating an individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating a difference between a predetermined first response time serving as a reference and a second response time measured for the fuel injection valve to be evaluated. Thereby, the individual difference in the injection response delay time of the fuel injection valve can be easily evaluated.

[0045] (2) The evaluation device according to the second aspect is an evaluation device that evaluates the injection response delay time from when an opening command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, and includes means for acquiring a measured value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by the injection of fuel from the fuel injection valve, means for measuring the response time from when the opening command is instructed until the measured value changes, means for calculating the injection response delay time based on the response time, and means for evaluating the individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating the difference between a predetermined first injection response delay time serving as a reference and a second injection response delay time measured for the fuel injection valve to be evaluated. Thereby, the individual difference in the injection response delay time of the fuel injection valve can be easily evaluated.

[0046] (3) The evaluation device according to the third aspect is the evaluation device of (1) to (2), wherein the sensor is a pressure sensor that detects a pressure drop of the fuel injection valve caused by the injection of fuel from the fuel injection valve, and the pressure sensor is provided upstream of the fuel injection valve in the fuel supply system. By simply attaching a pressure sensor, the individual difference in the injection response delay time of the fuel injection valve can be evaluated.

[0047] (4) The evaluation device according to the fourth aspect is the evaluation device of (1) to (3), wherein the sensor is a strain gauge that detects a change in the amount of strain of a component constituting the fuel supply system caused by the pressure drop of the fuel injection valve caused by the injection of fuel from the fuel injection valve, and the strain gauge is provided upstream of the fuel injection valve in the fuel supply system. By simply attaching a strain gauge, the individual difference in the injection response delay time of the fuel injection valve can be evaluated.

[0048] (5) The evaluation device according to the fifth aspect is the evaluation device of (1) to (4), wherein the sensor is a vibration sensor that detects the vibration of the fuel injection valve caused by the injection of fuel from the fuel injection valve, and the vibration sensor is provided on the fuel injection valve. By simply attaching a vibration sensor, it is possible to evaluate the individual differences in the injection response delay time of the fuel injection valve.

[0049] (6) The evaluation system according to the sixth aspect includes a fuel supply system including a fuel injection valve that injects fuel, a control device that controls the fuel injection valve, a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by the injection of fuel from the fuel injection valve, and the evaluation device according to any one of (1) to (5).

[0050] (7) The evaluation method according to the seventh aspect is an evaluation method for evaluating the injection response delay time from when an opening command is instructed to the fuel injection valve provided in the fuel supply system until fuel is injected from the fuel injection valve, including the steps of: obtaining a measurement value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by the injection of fuel from the fuel injection valve; measuring the response time from when the opening command is instructed until the measurement value changes; and calculating the difference between a predetermined first response time serving as a reference and a second response time measured for the fuel injection valve to be evaluated, thereby evaluating the individual difference in the injection response delay time of the fuel injection valve to be evaluated.

[0051] (8) The program according to the eighth aspect causes a computer to execute a process for evaluating an injection response delay time from when an open command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, the process including: obtaining a measured value of a sensor that detects a state change of the fuel supply system or the fuel injection valve caused by injection of fuel from the fuel injection valve; measuring a response time from when the open command is instructed until the measured value changes; and evaluating an individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating a difference between a predetermined first response time serving as a reference and a second response time measured for the fuel injection valve to be evaluated.

Explanation of Signs

[0052] 1 ··· Fuel tank 2 ··· High-pressure pump 3 ··· Accumulator 4 ··· Fuel injection valve 5 ··· Pipe 6 ··· Pressure sensor 7 ··· Strain gauge 8 ··· Vibration sensor 10 ··· Fuel supply system 20 ··· Measuring device 21 ··· Acquisition unit 22 ··· Evaluation unit 23 ··· Output unit 24 ··· Storage unit 30 ··· Control device 90 ··· Computer 91 ··· Processor 92 ··· Main memory 93 ··· Storage 94 ··· Interface 100 ··· Evaluation system

Claims

1. An evaluation device for evaluating an individual difference in injection response delay time from when an opening command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, comprising: means for acquiring a measured value of a sensor that detects a change in state of the fuel supply system or the fuel injection valve caused by fuel injection from the fuel injection valve; means for measuring a response time from when the opening command is instructed until the measured value changes; means for evaluating an individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating a difference between a predetermined first said response time as a reference and a second said response time measured for the fuel injection valve to be evaluated; means for outputting the difference as a compensation value for compensating for an individual difference in the injection response delay time, which is set in a control device of the fuel injection valve to be evaluated; An evaluation device comprising the above.

2. An evaluation device for evaluating an individual difference in injection response delay time from when an opening command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, comprising: means for acquiring a measured value of a sensor that detects a change in state of the fuel supply system or the fuel injection valve caused by fuel injection from the fuel injection valve; means for measuring a response time from when the opening command is instructed until the measured value changes; means for calculating the injection response delay time based on the response time; means for evaluating an individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating a difference between a predetermined first said injection response delay time as a reference and a second said injection response delay time measured for the fuel injection valve to be evaluated; means for outputting the difference as a compensation value for compensating for an individual difference in the injection response delay time, which is set in a control device of the fuel injection valve to be evaluated; An evaluation device comprising the above.

3. The sensor is a pressure sensor that detects a pressure drop of the fuel injection valve caused by fuel injection from the fuel injection valve, and the pressure sensor is provided on the upstream side of the fuel injection valve in the fuel supply system. The evaluation device according to Claim 1 or Claim 2.

4. The sensor is a strain gauge that detects a change in the amount of strain of components constituting the fuel supply system caused by a pressure drop of the fuel injection valve resulting from fuel injection from the fuel injection valve. The strain gauge is provided upstream of the fuel injection valve in the fuel supply system. The evaluation device according to claim 1 or claim 2.

5. The sensor is a vibration sensor that detects vibration of the fuel injection valve caused by fuel injection from the fuel injection valve. The vibration sensor is provided on the fuel injection valve. The evaluation device according to claim 1 or claim 2.

6. A fuel supply system including a fuel injection valve that injects fuel; A control device that controls the fuel injection valve; A sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by fuel injection from the fuel injection valve; The evaluation device according to claim 1 or claim 2; Comprising: When the evaluation of the individual difference in the injection response delay time is completed, the fuel injection valve is removed from the fuel supply system. Evaluation system.

7. An evaluation method executed by a computer for evaluating an individual difference in an injection response delay time from when an opening command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, comprising: Obtaining a measured value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by fuel injection from the fuel injection valve; Measuring a response time from when the opening command is instructed until the measured value changes; Evaluating an individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating a difference between a predetermined first said response time serving as a reference and a second said response time measured for the fuel injection valve to be evaluated; Outputting the difference as a compensation value for compensating for an individual difference in the injection response delay time set in a control device of the fuel injection valve to be evaluated; The evaluation method having.

8. In a computer, A process for evaluating an individual difference in an injection response delay time from when an opening command is instructed to a fuel injection valve provided in a fuel supply system until fuel is injected from the fuel injection valve, comprising: Obtaining a measured value of a sensor that detects a change in the state of the fuel supply system or the fuel injection valve caused by fuel injection from the fuel injection valve; A step of measuring a response time from when the opening command is instructed until the measured value changes; A step of evaluating an individual difference in the injection response delay time of the fuel injection valve to be evaluated by calculating a difference between a predetermined first said response time as a reference and a second said response time measured for the fuel injection valve to be evaluated; A step of outputting the difference as a compensation value for compensating for the individual difference in the injection response delay time, which is set in the control device of the fuel injection valve to be evaluated; A program for executing a process having the above.

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