JP2023086416A - Engine control device manufacturing method, engine system and engine system control method - Google Patents

Abstract

To improve performance aggravation of an engine, due to fluctuation of compression ratios of the engine, as needed.SOLUTION: A manufacturing method of an ECU controlling an engine mounted with a plurality of cylinders comprises the steps of: identifying compression ratios of respective cylinders (S11 and S12); calculating maximum inner cylinder pressure of respective cylinders using the compression ratios (S13); calculating margins which are differences between the largest maximum inner cylinder pressure and the maximum inner cylinder pressure of respective cylinders (S14); identifying offset amounts with which injection timings indicated in a normal control map of fuel injection timings are advanced so as to increase inner cylinder pressures of respective cylinders by the margins (S15); and causing a memory of the ECU to store a program which controls the injection timings in a manner that advances the injection timings indicated in the normal control map by the offset amounts to prevent the offset amounts to advance ignition timings when an engine load is large from getting smaller than the same when the engine load is small (S16).SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD This disclosure relates to a method of manufacturing an engine control device, an engine system, and a method of controlling the engine system, and more particularly, to a method of manufacturing an engine control device for controlling a diesel engine having multiple cylinders, a diesel engine having multiple cylinders, and a method of controlling the engine system. , an engine system including a control device having a control unit and a storage unit for controlling a diesel engine, and a control method for the engine system.

Conventionally, there has been a control method for individually correcting engine control conditions according to factors that determine the compression ratio for each cylinder when there is variation in the compression ratio for each cylinder of a multi-cylinder engine (for example, Patent Document 1 reference).

Japanese Patent Application Laid-Open No. 2002-303191

However, in the method of Patent Document 1, the control conditions of the engine are individually corrected in all control ranges, so there is a problem that unnecessary control is performed in the control range where the influence of individual correction is small.

This disclosure has been made to solve the above-mentioned problems, and the object thereof is to provide an engine control system capable of improving, as necessary, deterioration in performance caused by variations in the compression ratio of the engine. An object of the present invention is to provide a device manufacturing method, an engine system, and a control method for the engine system.

A manufacturing method of an engine control device according to this disclosure is a manufacturing method of an engine control device that controls a diesel engine having a plurality of cylinders. The engine control device has a storage unit. The manufacturing method includes steps of specifying a compression ratio of each cylinder of a diesel engine, calculating a maximum in-cylinder pressure of each cylinder using the specified compression ratio, calculating the largest of the calculated maximum in-cylinder pressures and each cylinder. A step of calculating a margin that is the difference between the maximum cylinder pressure and the fuel injection timing shown in the normal control map of the fuel injection timing to increase the cylinder pressure of each cylinder by the calculated margin of each cylinder A step of specifying an offset amount to advance the timing, and specifying the injection timing indicated by the normal control map so that the offset amount to advance does not decrease when the load of the diesel engine is large compared to when the load is small. and a step of storing in the storage unit a program for controlling to advance the angle by the offset amount.

Preferably, the program is a program that advances the injection timing indicated by the normal control map by the specified offset amount when the load of the diesel engine is equal to or higher than a predetermined load. More preferably, the predetermined load is determined in advance based on the effect on noise generated by the diesel engine when the injection timing is advanced by the offset amount.

Preferably, the program is a program that advances the injection timing indicated by the normal control map by increasing the reflection ratio of the offset amount in stages according to the load of the diesel engine.

Preferably, the program is a program that advances the injection timing indicated by the normal control map by monotonously increasing the reflection ratio of the offset amount according to the load of the diesel engine.

According to another aspect of this disclosure, an engine system is an engine system that includes a diesel engine having multiple cylinders and a control device that includes a control unit and a storage unit and controls the diesel engine. The storage unit stores the injection timing shown in the normal fuel injection timing control map by the offset amount so that the offset amount to be advanced does not become small when the load of the diesel engine is large compared to when the load is small. A program for controlling advance is stored in advance. The offset amount is an amount by which the injection timing shown in the normal control map is advanced in order to increase the in-cylinder pressure of each cylinder by the margin of each cylinder. The allowance is the difference between the largest maximum in-cylinder pressure of each cylinder and the maximum in-cylinder pressure of each cylinder. The maximum in-cylinder pressure is calculated using the compression ratio of each cylinder. A compression ratio is specified for each cylinder. The control unit determines whether or not the load of the diesel engine is greater than when the load is small according to the program stored in the storage unit, and when it is determined that the load of the diesel engine is greater than when the load is light. , control is performed to advance the injection timing indicated by the normal control map by the offset amount so that the offset amount does not become small.

According to still another aspect of the present disclosure, an engine system control method includes a diesel engine having a plurality of cylinders and a control device having a control unit and a storage unit for controlling the diesel engine. be. The storage unit stores the injection timing shown in the normal fuel injection timing control map by the offset amount so that the offset amount to be advanced does not become small when the load of the diesel engine is large compared to when the load is small. A program for controlling advance is stored in advance. The offset amount is an amount by which the injection timing shown in the normal control map is advanced in order to increase the in-cylinder pressure of each cylinder by the margin of each cylinder. The allowance is the difference between the largest maximum in-cylinder pressure of each cylinder and the maximum in-cylinder pressure of each cylinder. The maximum in-cylinder pressure is calculated using the compression ratio of each cylinder. A compression ratio is specified for each cylinder. The control method comprises the steps of: determining whether the load on the diesel engine is greater than when the load on the diesel engine is low, according to a program stored in the storage unit; and a step of controlling the injection timing shown in the normal control map to advance by the offset amount so that the offset amount does not become small when it is determined that the offset amount is larger than the offset amount.

According to this disclosure, the injection timing indicated by the normal control map is adjusted by the specified offset amount so that the advanced offset amount does not become small when the load of the diesel engine is large compared to when the load is small. , the maximum in-cylinder pressure of the advanced cylinder is increased by the difference from the maximum maximum in-cylinder pressure of each cylinder. As a result, it is intended to provide a method for manufacturing an engine control device, an engine system, and a method for controlling the engine system, which can improve the deterioration of performance caused by variations in the compression ratio of a diesel engine as necessary. can be done.

1 is a diagram showing a schematic configuration of an engine provided with a cooling device according to an embodiment; FIG. 4 is a flow chart showing a schematic flow of a method for manufacturing part of a program for controlling an engine in this embodiment; It is a figure for demonstrating the amount of protrusions of the piston of this embodiment. 5 is a graph showing an example of actual values of compression ratios in this embodiment; 4 is a graph showing an example of actual values of maximum in-cylinder pressure in this embodiment. 4 is a graph showing the relationship between the fuel injection timing and the in-cylinder pressure of the engine in this embodiment. 4 is a graph showing the relationship between fuel injection timing and output of the engine in this embodiment. 5 is a graph for explaining control of an engine by an ECU manufactured in this embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, identical parts are provided with identical reference numerals. Their names and functions are also the same. A detailed description thereof will therefore not be repeated.

FIG. 1 is a diagram showing a schematic configuration of an engine 1 equipped with a cooling device according to this embodiment. Although the cross section of one cylinder of the engine 1 is representatively shown schematically in FIG. . Moreover, the engine 1 is a diesel engine.

Engine 1 includes a cylinder head 2 and a cylinder block 3 . Injectors (fuel injection valves) 5 for injecting fuel into the combustion chamber 4 are provided in portions of the cylinder head 2 corresponding to the respective cylinders. The injector 5 is connected to a common rail (not shown), and is constantly supplied with high-pressure fuel stored in the common rail.

An intake passage for drawing air into the combustion chamber 4 is connected to the cylinder head 2 via an intake manifold 8 . An exhaust passage for discharging exhaust gas after combustion is connected to the cylinder head 2 via an exhaust manifold 10 . An intake valve 11 opens and closes between the combustion chamber 4 and the intake manifold 8 . An exhaust valve 12 opens and closes between the combustion chamber 4 and the exhaust manifold 10 .

A piston 26 is housed inside the cylinder block 3 so as to be able to reciprocate. Piston 26 is connected to crankshaft 27 via connecting rod 28 . A head gasket 6 is interposed between the cylinder block 3 and the cylinder head 2 when the two are combined. The thickness of the head gasket 6 is the thickness of the piston 26 at the top dead center where the piston 26 is positioned at the top of its stroke (the position closest to the cylinder head 2 and the position furthest from the crankshaft 27) when the engine 1 is assembled. The thickness is determined so that the upper end (the portion closest to the cylinder head 2) does not contact the lower surface of the cylinder head 2 (the surface closer to the cylinder block 3).

Engine 1 further includes an electronic control unit (ECU) 40 . ECU 40 includes a memory 42 that stores predetermined programs and predetermined data, and a CPU (Central Processing Unit) 41 that executes predetermined programs stored in memory 42 and controls engine 1 . The ECU 40 is supplied with the accelerator opening Acc, the engine rotational speed Ne, and the like from various sensors.

The ECU 40 acquires the accelerator opening Acc and the engine rotation speed Ne, performs predetermined processing, and controls the injector 5 to control the injection of fuel into the combustion chamber 4 .

In the configuration as described above, when the compression ratio of each cylinder of the engine 1 varies, when the control conditions of the engine 1 are individually corrected according to the factors that determine the compression ratio of each cylinder, in all control ranges, , if the control conditions of the engine 1 are individually corrected, less necessary control is performed in a control range where the influence of the individual correction is small.

Therefore, the method of manufacturing the ECU 40 is a method of manufacturing a control device that controls the engine 1 having a plurality of cylinders. The ECU 40 has a storage section. The manufacturing method includes steps of specifying a compression ratio of each cylinder of a diesel engine, calculating a maximum in-cylinder pressure of each cylinder using the specified compression ratio, calculating the largest of the calculated maximum in-cylinder pressures and each cylinder. A step of calculating a margin that is the difference between the maximum cylinder pressure and the fuel injection timing shown in the normal control map of the fuel injection timing to increase the cylinder pressure of each cylinder by the calculated margin of each cylinder A step of specifying an offset amount to advance the timing, and specifying the injection timing indicated by the normal control map so that the offset amount to advance does not decrease when the load of the diesel engine is large compared to when the load is small. and a step of storing in the storage unit a program for controlling to advance the angle by the offset amount.

As a result, the injection timing indicated by the normal control map is advanced by the specified offset amount so that the advanced offset amount does not become smaller when the load on the engine 1 is larger than when the load is small. As a result, the maximum in-cylinder pressure of the advanced cylinder is increased by the difference from the maximum maximum in-cylinder pressure of each cylinder. As a result, deterioration in performance caused by variations in the compression ratio of the engine 1 can be improved as necessary.

FIG. 2 is a flow chart showing a schematic flow of a method for manufacturing part of the program for controlling the engine 1 in this embodiment. Referring to FIG. 2, the manufacturer measures the protrusion amount h of the piston 26 from the cylinder block 3 when installing the piston 26 in each cylinder of the cylinder block 3 in manufacturing the engine 1 (step S11).

FIG. 3 is a diagram for explaining the amount of protrusion of the piston 26 of this embodiment. Referring to FIG. 3, the protrusion amount h of the piston 26 is the length by which the upper end of the piston 26 protrudes from the upper surface of the cylinder block 3 at the top dead center.

The amount h of protrusion can vary from cylinder to cylinder because the dimensions of the piston 26, connecting rod 28, and crankshaft 27 differ from cylinder to cylinder within a tolerance range. This protrusion amount is measured in step S11.

Returning to FIG. 2, the manufacturer calculates the compression ratio of each cylinder using the protrusion amount h measured in step S11 (step S12). The compression ratio is a value obtained by dividing the maximum volume of the combustion chamber 4 by the minimum volume. The volume of the piston recess is also included in the volume of the combustion chamber 4 . In calculating the compression ratio, the thickness of the head gasket 6 sandwiched between the cylinder head 2 and the cylinder block 3 is also taken into consideration.

FIG. 4 is a graph showing an example of actual compression ratio values in this embodiment. Referring to FIG. 4, the design value (standard value) of the compression ratio of engine 1 in this embodiment is a value calculated from the dimensions of each component on the design drawing. Here, the design value of the compression ratio is the value indicated by the leftmost STD bar graph and the thick dashed line between the thin solid line indicating the compression ratio of 15.3 and the thin solid line indicating the compression ratio of 15.4.

The design upper limit value of the compression ratio of the engine 1 is a value calculated from the maximum or minimum dimensional tolerance of each part on the design drawing. Here, the design upper limit value is the value indicated by the thick solid line between the thin solid line indicating the compression ratio of 15.5 and the thin solid line indicating the compression ratio of 15.6.

The design upper limit value of the compression ratio of the engine 1 is a value calculated from the maximum or minimum dimensional tolerance of each part on the design drawing. Here, the design upper limit value is the value indicated by the thick solid line that substantially overlaps the line indicating the compression ratio of 15.2.

The compression ratio values calculated in step S12 for each cylinder No. 1 to No. 6 are the values indicated by the bars #1 to #6 on the right side of the STD bar graph in FIG. . Here, the compression ratio of the first cylinder is the maximum value among the compression ratios of all the first to sixth cylinders. This maximum is indicated by a thin dashed line that nearly overlaps the line representing a compression ratio of 15.5.

Returning to FIG. 2, the manufacturer calculates the maximum in-cylinder pressure of each cylinder from the compression ratio of each cylinder calculated in step S12 (step S13). Assuming that the operating conditions of the engine 1 other than the compression ratio are the same, the maximum in-cylinder pressure increases approximately proportionally as the compression ratio increases. The relationship between various compression ratio values and the maximum in-cylinder pressure under the operating condition of the engine 1 with the highest load is specified in advance by simulation or actual measurement at the time of design. Using this relationship, the maximum in-cylinder pressure is calculated from the compression ratio for each cylinder.

FIG. 5 is a graph showing an example of actual maximum in-cylinder pressure values in this embodiment. Referring to FIG. 5, the design value of the maximum in-cylinder pressure is a value specified from the design values of the dimensions of each part, the design values of the compression ratio, and the like. Here, the design value of the maximum in-cylinder pressure is the value indicated by the thick dashed line between the thin solid line indicating the maximum in-cylinder pressure of 15.5 (MPa) and the thin solid line indicating the maximum in-cylinder pressure of 16.0.

The design upper limit value of the maximum in-cylinder pressure is a value specified from the maximum value or minimum value of dimensional tolerance on the design drawing of each component and the design upper limit value or design lower limit value of the compression ratio. Here, the design upper limit value of the maximum in-cylinder pressure is the value indicated by the thick solid line between the thin solid line indicating the maximum in-cylinder pressure of 16.0 (MPa) and the thin solid line indicating the maximum in-cylinder pressure of 16.5.

The values of the maximum in-cylinder pressures calculated in step S13 for each of cylinders No. 1 to No. 6 are the values indicated by the bar graphs #1 to #6 in FIG. 5, respectively. Here, the maximum in-cylinder pressure of the first cylinder is the maximum value among the maximum in-cylinder pressures of all the first to sixth cylinders. This maximum value is the value indicated by the thin dashed line between the thin solid line indicating the maximum in-cylinder pressure of 16.0 (MPa) and the thin solid line indicating the maximum in-cylinder pressure of 16.5.

Returning to FIG. 2, the manufacturer calculates a margin for the maximum in-cylinder pressure of each cylinder from the maximum in-cylinder pressure calculated in step S13 (step S14).

Referring to FIG. 5 again, here, the maximum cylinder pressure of the first cylinder is the maximum value, so the allowance, which is the difference between the maximum cylinder pressure of each cylinder and the maximum cylinder pressure of the first cylinder, is Calculated.

Returning to FIG. 2, the manufacturer calculates, for each engine rotation speed Ne, an advance angle offset amount that can use up the allowance calculated in step S14 (step S15).

FIG. 6 is a graph showing the relationship between the fuel injection timing of the engine 1 and the in-cylinder pressure in this embodiment. Referring to FIG. 6, this graph is for a certain engine rotation speed Ne. The injection timing is indicated by an angle after top dead center (ATDC (After Top Dead Center)). If the ATDC angle is a negative value, the absolute value of this angle indicates the angle "before" top dead center.

As shown in the graph of FIG. 6, the smaller the ATDC angle indicating the injection timing, that is, the more the injection timing is advanced (the greater the offset amount of the advance of the injection timing), the higher the in-cylinder pressure. . The same tendency is observed at other engine rotation speeds Ne. From this graph, it is possible to specify the angle by which the injection timing is advanced in order to increase the maximum in-cylinder pressure by the margin at a certain engine rotation speed Ne. In this way, the angle for advancing the injection timing is specified for each engine rotation speed at predetermined rotation speed intervals (for example, 100 rpm intervals).

FIG. 7 is a graph showing the relationship between the fuel injection timing and the output of the engine 1 in this embodiment. Referring to FIG. 7, for a certain cylinder, the smaller the ATDC angle indicating the injection timing, that is, the more the injection timing is advanced (the greater the offset amount of the advance of the injection timing), the more the output of the cylinder. becomes larger. Therefore, if the maximum in-cylinder pressure of a certain cylinder is increased by the margin, the output of the cylinder also increases.

Returning to FIG. 2, the manufacturer adds an offset amount for advancing the injection timing shown in the normal control map (turns on the offset amount addition control) when using the engine 1 with a load greater than the specified one. Otherwise (when using a load less than the one designated by the engine 1), create a program that does not add the offset amount (turn off the addition control of the offset amount), and store the created program in the memory 42 of the ECU 40 of the engine 1. Let The normal control map of injection timing is a control map of injection timing that is normally used for the engine 1, and is a control map in a state where addition control of the offset amount in this embodiment is not performed.

FIG. 8 is a graph for explaining control of the engine 1 by the ECU 40 manufactured in this embodiment. Referring to FIG. 8, when the engine 1 with this program incorporated in the ECU 40 is operated, when the load of the engine 1 exceeds the designated load at time t, the ECU 40 follows this program to: Addition control of the offset amount is turned on. As a result, the maximum in-cylinder pressure of each cylinder increases by the margin, and the output of the cylinder increases, so the output of the engine 1 increases.

The designated load is determined in advance based on the effect on noise generated by the engine 1 when the injection timing is advanced by the offset amount. For example, in a state where the noise level does not exceed the predetermined allowable value, when the injection timing is advanced by the offset amount, the load whose noise level does not exceed the predetermined allowable value and the noise level which exceeds the predetermined allowable value Let the load at the boundary with the load be the specified load.

[Modification]
(1) In the above-described embodiment, as shown in step S16 of FIG. 2 and FIG. The program controls the injection timing to be advanced by the offset amount. In other words, the program to be created is, for example, a program that advances the angle by 100% of the offset amount when the load of the engine 1 is 90% or more of the maximum load.

However, the present invention is not limited to this, and the created program advances the injection timing indicated by the normal control map so that the advance offset amount does not become small when the load of the engine 1 is large compared to when it is small. Any program can be used as long as it controls the angle. For example, the created program may be a program that advances the control timing shown in the normal control map step by step according to the load of the engine 1 by increasing the reflection ratio of the offset amount. . That is, for example, the created program controls to advance by 30% of the offset amount when the load of the engine 1 is 50% or more of the maximum load, and when it is 75% or more of the maximum load , 60% of the offset amount, and control to advance 100% of the offset amount when the load is 100% or more of the maximum load.

Further, the program to be created may be a program for controlling the injection timing shown in the normal control map to be advanced by monotonically increasing according to the load of the engine 1 and increasing the reflection ratio of the offset amount. . That is, the program to be created may be a program that advances the engine 1 by 100-x(%) of the offset amount when the load of the engine 1 is x% of the maximum load.

(2) In the above-described embodiment, as shown in step S16 of FIG. 2 and FIG. 8, when the noise level of the designated load does not exceed the predetermined allowable value, the injection timing is adjusted by the offset amount. is advanced, the load is on the boundary between a load whose noise level does not exceed a predetermined allowable value and a load whose noise level exceeds a predetermined allowable value. However, it is not limited to this, and when the specified load advances the injection timing by the amount of the offset, the load that people feel becomes louder than before advancing the injection timing and the load before advancing the injection timing. The specified load may be the load on the boundary between the load at which the user does not feel that the noise has increased.

(3) In the above-described embodiment, the multi-stage injection is not particularly mentioned. At least one stage including the first stage injection (for example, pilot injection) of each stage may be advanced by the offset amount, or a plurality of stages of d stage injection may be advanced. When advancing the angle, the angle may be advanced by a different amount of offset.

(4) The above disclosure can be regarded as disclosure of an engine control device such as the ECU 40 of the engine 1 or a method of manufacturing a program executed by this control device. It can be regarded as disclosure of the engine 1 , a control device such as the ECU 40 of the engine 1 , and an engine system including the engine 1 and the ECU 40 . It can be regarded as disclosure of a control method of the engine 1 by a control device such as the ECU 40 of the engine 1 .

[summary]
(1) As shown in FIG. 2, the manufacturing method of the ECU 40 is a manufacturing method of the ECU 40 that controls the engine 1, which is a diesel engine having a plurality of cylinders. The ECU 40 has a memory 42 . The manufacturing method includes a step of specifying the compression ratio of each cylinder of the engine 1 (for example, steps S11 and S12) and a step of calculating the maximum in-cylinder pressure of each cylinder using the specified compression ratio (for example, step S13). Then, a step (for example, step S14) of calculating an allowance, which is the difference between the largest of the calculated maximum in-cylinder pressures and the maximum in-cylinder pressure of each cylinder; A step (for example, step S15) of specifying an offset amount for advancing the injection timing indicated by the normal control map of the fuel injection timing, in order to increase the in-cylinder pressure of the engine 1, and comparing with when the load of the engine 1 is small. A step of storing in the memory 42 a program (for example, step S16).

As a result, the injection timing indicated by the normal control map is advanced by the specified offset amount so that the advanced offset amount does not become smaller when the load on the engine 1 is larger than when the load is small. As a result, the maximum in-cylinder pressure of the advanced cylinder is increased by the difference from the maximum maximum in-cylinder pressure of each cylinder. As a result, deterioration in performance caused by variations in the compression ratio of the engine 1 can be improved as necessary. Specifically, the output of the engine 1 can be increased when the load on the engine 1 is large compared to when the load is small.

(2) As shown in step S16 of FIG. 2 and FIG. 8, the program stored in the memory 42 adjusts the injection timing indicated by the normal control map when the load of the engine 1 is greater than or equal to the designated load. , and the calculated offset amount.

As a result, when the load of the engine 1 is equal to or higher than the specified load, the injection timing indicated by the normal control map is advanced by the calculated offset amount, thereby increasing the maximum number of advanced cylinders. The in-cylinder pressure is increased by the difference from the maximum maximum in-cylinder pressure of each cylinder. As a result, deterioration in performance caused by variations in the compression ratio of the engine 1 can be improved as necessary. Specifically, when the load of the engine 1 is greater than or equal to the designated load, the output of the engine 1 can be increased by advancing the angle compared to when the angle is not advanced.

(3) As shown in step S16 of FIG. 2 and FIG. 8, the specified load is determined in advance based on the effect on the noise generated by the engine 1 when the injection timing is advanced by the offset amount. be done.

As a result, the designated load can be determined in consideration of the noise-related influence, so that the adverse effect of noise can be reduced.

(4) As shown in the modified example above, the program stored in the memory 42 adjusts the injection timing indicated by the normal control map by stepwise increasing the reflection rate of the offset amount according to the load of the engine 1. , may be a program that controls to advance the angle.

As a result, the injection timing indicated by the normal control map is advanced by increasing the offset amount reflection ratio in stages according to the load of the engine 1, and the maximum in-cylinder pressure of the advanced cylinder is , is increased up to the difference from the largest maximum in-cylinder pressure of each cylinder. As a result, deterioration in performance caused by variations in the compression ratio of the engine 1 can be improved as necessary. Specifically, the output of the engine 1 can be increased stepwise according to the load of the engine 1 .

(5) As shown in the modification above, the program stored in the memory 42 monotonically increases the injection timing indicated by the normal control map according to the load of the engine 1 by increasing the reflection ratio of the offset amount. , may be a program that controls to advance the angle.

As a result, the injection timing shown in the normal control map is advanced by monotonously increasing the reflection ratio of the offset amount according to the load of the engine 1, and the maximum in-cylinder pressure of the advanced cylinder is , is increased up to the difference from the largest maximum in-cylinder pressure of each cylinder. As a result, deterioration in performance caused by variations in the compression ratio of the engine 1 can be improved as necessary. Specifically, the output of the engine 1 can be monotonically increased according to the load of the engine 1 .

(6) As shown in FIG. 1, the engine system includes an engine 1 having a plurality of cylinders and an ECU 40 having a CPU 41 and a memory 42 and controlling the engine 1 . As shown in step S16 in FIG. 2, the memory 42 stores the normal control map of the fuel injection timing so that the offset amount to be advanced does not become small when the load of the engine 1 is large compared to when the load is small. A program is stored in advance to advance the indicated injection timing by the offset amount. As shown in step S15 in FIG. 2, the offset amount is an amount by which the injection timing shown in the normal control map is advanced in order to increase the in-cylinder pressure of each cylinder by the margin of each cylinder. As shown in step S14 in FIG. 2, the allowance is the difference between the largest maximum in-cylinder pressure of each cylinder and the maximum in-cylinder pressure of each cylinder. As shown in step S13 in FIG. 2, the maximum in-cylinder pressure is calculated using the compression ratio of each cylinder. As shown in steps S11 and S12 of FIG. 2, the compression ratio is specified for each cylinder. As shown in step S16 of FIG. 2 and FIG. 8, the CPU 41 determines whether or not the load on the engine 1 is greater than when the load on the engine 1 is low, according to the program stored in the memory 42. is larger than when it is small, the injection timing shown in the normal control map is controlled to advance by the amount of the offset so that the offset does not become small.

As a result, the injection timing indicated by the normal control map is advanced by the specified offset amount so that the advanced offset amount does not become smaller when the load on the engine 1 is larger than when the load is small. As a result, the maximum in-cylinder pressure of the advanced cylinder is increased by the difference from the maximum maximum in-cylinder pressure of each cylinder. As a result, deterioration in performance caused by variations in the compression ratio of the engine 1 can be improved as necessary. Specifically, the output of the engine 1 can be increased when the load on the engine 1 is large compared to when the load is small.

(7) As shown in FIG. 1, the engine system control method includes the engine 1 having a plurality of cylinders and the ECU 40 having the CPU 41 and the memory 42 and controlling the engine 1 . As shown in step S16 in FIG. 2, the memory 42 stores the normal control map of the fuel injection timing so that the offset amount to be advanced does not become small when the load of the engine 1 is large compared to when the load is small. A program is stored in advance to advance the indicated injection timing by the offset amount. As shown in step S15 in FIG. 2, the offset amount is an amount by which the injection timing shown in the normal control map is advanced in order to increase the in-cylinder pressure of each cylinder by the margin of each cylinder. As shown in step S14 in FIG. 2, the allowance is the difference between the largest maximum in-cylinder pressure of each cylinder and the maximum in-cylinder pressure of each cylinder. As shown in step S13 in FIG. 2, the maximum in-cylinder pressure is calculated using the compression ratio of each cylinder. As shown in steps S11 and S12 of FIG. 2, the compression ratio is specified for each cylinder. As shown in step S16 of FIG. 2 and FIG. 8, the control method is a step in which the CPU 41 determines whether or not the load on the engine 1 is greater than when it is light, according to the program stored in the memory 42. When the CPU 41 determines that the load on the engine 1 is large compared to when it is small, the injection timing indicated by the normal control map is advanced by the offset amount so that the offset amount does not become small. and controlling.

As a result, the injection timing indicated by the normal control map is advanced by the specified offset amount so that the advanced offset amount does not become smaller when the load on the engine 1 is larger than when the load is small. As a result, the maximum in-cylinder pressure of the advanced cylinder is increased by the difference from the maximum maximum in-cylinder pressure of each cylinder. As a result, deterioration in performance caused by variations in the compression ratio of the engine 1 can be improved as necessary. Specifically, the output of the engine 1 can be increased when the load on the engine 1 is large compared to when the load is small.

It is also planned to implement each embodiment disclosed this time in appropriate combination. And the embodiment disclosed this time should be considered as an illustration and not restrictive in all respects. The scope of the present disclosure is indicated by the scope of claims rather than the description of the above-described embodiments, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 engine, 2 cylinder head, 3 cylinder block, 4 combustion chamber, 5 injector, 6 head gasket, 8 intake manifold, 10 exhaust manifold, 11 intake valve, 12 exhaust valve, 26 piston, 27 crankshaft, 28 connecting rod, 40 ECU , 41 CPU, 42 memory.

Claims (7)

A method for manufacturing an engine control device for controlling a diesel engine having a plurality of cylinders,
The engine control device includes a storage unit,
The manufacturing method is
identifying a compression ratio for each cylinder of the diesel engine;
calculating the maximum in-cylinder pressure of each cylinder using the identified compression ratio;
calculating a margin that is a difference between the largest of the calculated maximum in-cylinder pressures and the maximum in-cylinder pressure of each cylinder;
specifying an offset amount for advancing the injection timing shown in the normal control map of the fuel injection timing, in order to increase the in-cylinder pressure of each cylinder by the calculated margin for each cylinder;
When the load of the diesel engine is large compared to when the load is small, the injection timing indicated by the normal control map is advanced by the specified offset amount so that the advanced offset amount does not become small. A method for manufacturing an engine control device, comprising a step of storing a program for controlling the engine control in the storage unit. 2. The program controls to advance the injection timing indicated by the normal control map by the specified offset amount when the load of the diesel engine is equal to or higher than a predetermined load. A method of manufacturing the engine control device according to 1. 3. The method of manufacturing an engine control device according to claim 2, wherein said predetermined load is determined in advance based on an effect on noise generated by said diesel engine when said injection timing is advanced by said offset amount. 2. The program according to claim 1, wherein the program controls to advance the injection timing indicated by the normal control map by stepwise increasing the reflection ratio of the offset amount according to the load of the diesel engine. A method of manufacturing the described engine control device. 2. The program according to claim 1, wherein the program controls to advance the injection timing indicated by the normal control map by monotonically increasing the reflection ratio of the offset amount according to the load of the diesel engine. A method of manufacturing the described engine control device. An engine system including a diesel engine having a plurality of cylinders and a control device having a control unit and a storage unit for controlling the diesel engine,
The storage unit stores the injection timing indicated by the normal control map of the fuel injection timing so that the offset amount to be advanced does not decrease when the load of the diesel engine is large compared to when the load is small. Pre-store a program that controls to advance the minute,
The offset amount is an amount for advancing the injection timing indicated by the normal control map in order to increase the in-cylinder pressure of each cylinder by the margin of each cylinder,
The margin is the difference between the maximum in-cylinder pressure of each cylinder and the maximum in-cylinder pressure of each cylinder,
The maximum in-cylinder pressure is calculated using the compression ratio of each cylinder,
The compression ratio is specified for each cylinder,
The control unit, according to the program stored in the storage unit,
Determining whether the load of the diesel engine is larger than when it is small,
When it is determined that the load of the diesel engine is larger than when the load is small, the injection timing indicated by the normal control map is controlled to advance by the offset amount so that the offset amount does not decrease. engine system. A control method for an engine system including a diesel engine having a plurality of cylinders and a control device having a control unit and a storage unit for controlling the diesel engine,
The storage unit stores the injection timing indicated by the normal control map of the fuel injection timing so that the offset amount to be advanced does not decrease when the load of the diesel engine is large compared to when the load is small. Pre-store a program that controls to advance the minute,
The offset amount is an amount for advancing the injection timing indicated by the normal control map in order to increase the in-cylinder pressure of each cylinder by the margin of each cylinder,
The margin is the difference between the maximum in-cylinder pressure of each cylinder and the maximum in-cylinder pressure of each cylinder,
The maximum in-cylinder pressure is calculated using the compression ratio of each cylinder,
The compression ratio is specified for each cylinder,
According to the program stored in the storage unit, the control method includes:
a step in which the control unit determines whether the load of the diesel engine is greater than when the load is small;
When the control unit determines that the load of the diesel engine is large compared to when the load is small, the injection timing indicated by the normal control map is changed by the offset amount so that the offset amount does not become small. A method of controlling an engine system, comprising: controlling to advance the angle.

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