JPWO2018101411A1 - Fuel injection device - Google Patents

Abstract

The fuel injection device (1) of the embodiment injects fuel into a combustion chamber (CC) of an internal combustion engine (EG). The fuel injection device (1) includes a pressure accumulator (122) to which fuel is supplied from a high pressure source (4) that supplies fuel at a predetermined pressure, and a fuel that is supplied from the high pressure source (4) to the accumulator (122). A first valve (21) to be supplied to the inside, and a second valve (22) to inject fuel supplied to the pressure accumulator (122) from the pressure accumulator (122) into the combustion chamber (CC).

Description

The present invention relates to a fuel injection device.
This application claims priority based on the Japan patent application No. 2016-235334 for which it applied on December 2, 2016, and uses the content here.

Research and development of technologies related to the combustion of fuel in the combustion chamber of an internal combustion engine are being conducted.

In this regard, a device for injecting fuel into a combustion chamber of an internal combustion engine is provided with a high-pressure source, a pressure intensifier, and a metering valve, and the pressure intensifier has a working chamber and a control chamber. Both chambers are separated from each other by a movable piston, so that the pressure change in the control chamber of the intensifier causes a pressure change in the compression chamber of the intensifier, In the type in which the nozzle chamber surrounding the injection valve member is loaded through the inflow passage, a valve body is provided in the control line between the control chamber of the pressure intensifier and the metering valve. The pressure relief valve is arranged, and the valve body is adapted to load at least one hydraulic chamber of the pressure relief valve, and the chamber can be connected to the pressure formed in the high pressure accumulator chamber. A device for injecting fuel into the combustion chamber of an internal combustion engine is known That (see Patent Document 1).

Japanese National Table 2005-53712

According to Patent Document 1, a device for injecting fuel into a combustion chamber of an internal combustion engine is provided with a common rail as a high-pressure source that supplies fuel with reference pressure. The apparatus increases the pressure of the fuel injected into the combustion chamber of the internal combustion engine using a pressure increasing mechanism to a pressure higher than the reference pressure of the high pressure source. At that time, the device needs to discharge a part of the high-pressure fuel to the outside different from the combustion chamber in order to operate the pressure increasing mechanism. In this case, the amount of fuel released to the outside by operating the pressure increasing mechanism using fuel is larger than the amount of fuel injected into the combustion chamber. For this reason, the said apparatus will dissipate a part of energy which the fuel of the said high pressure has as heat energy. That is, the apparatus increases the fuel consumption rate by the amount of energy dissipated as thermal energy.

Accordingly, the present invention has been made in view of the above-described problems of the prior art, and is capable of changing the pressure of the fuel injected into the combustion chamber to a pressure desired by the user while suppressing an increase in the fuel consumption rate. An injection device is provided.

In order to solve the above-described problem, a fuel injection device according to one aspect of the present invention is a fuel injection device that injects fuel into a combustion chamber of an internal combustion engine, and includes a high-pressure source that supplies the fuel at a predetermined pressure. A pressure accumulating unit to which fuel is supplied, a first valve for supplying the fuel supplied from the high pressure source to the inside of the pressure accumulating unit, and the fuel supplied to the pressure accumulating unit from the pressure accumulating unit to the combustion chamber A second valve to be injected.

In order to solve the above-described problem, a fuel injection device according to one aspect of the present invention is a fuel injection device that injects fuel into a combustion chamber of an internal combustion engine, and injects the fuel into the combustion chamber. A high pressure source that supplies the fuel to the injection unit with a predetermined pressure, and a pressure reduction unit that reduces the pressure of the fuel provided between the injection unit and the high pressure source.

In order to solve the above-described problem, a fuel injection device according to an aspect of the present invention is a fuel injection device that injects fuel into a combustion chamber of an internal combustion engine, and is supplied from a high-pressure source at a predetermined pressure. The pressure at which the fuel is injected into the combustion chamber can be changed to a pressure equal to or lower than the predetermined pressure corresponding to each of at least three or more stages.

ADVANTAGE OF THE INVENTION According to this invention, the fuel-injection apparatus which can change the pressure of the fuel injected into a combustion chamber into the pressure which a user desires can be provided, suppressing the increase in a fuel consumption rate.

1 is a diagram illustrating an example of a configuration of a fuel injection device 1. FIG. 1 is a diagram illustrating an example of a logical structure of a fuel injection device 1. FIG. It is a figure which shows an example of the hardware constitutions of ECU3. It is a figure which shows an example of a function structure of ECU3. 4 is a timing chart for explaining a specific example 1 of the control method of the fuel injection device 1; 6 is a timing chart for explaining a specific example 2 of the control method of the fuel injection device 1; 6 is a timing chart for explaining a specific example 3 of the control method of the fuel injection device 1; 6 is a timing chart for explaining a specific example 4 of the control method of the fuel injection device 1; 6 is a timing chart for explaining a specific example 5 of the control method of the fuel injection device 1; 7 is a timing chart for explaining a specific example 6 of the control method of the fuel injection device 1; 10 is a timing chart for explaining a specific example 7 of the control method of the fuel injection device 1; 10 is a timing chart for explaining a specific example 8 of the control method of the fuel injection device 1; 10 is a timing chart for explaining a specific example 9 of the control method of the fuel injection device 1; 10 is a timing chart for explaining a specific example 10 of the control method of the fuel injection device 1; 10 is a timing chart for explaining a specific example 11 of the control method of the fuel injection device 1; 10 is a timing chart for explaining a specific example 12 of the control method of the fuel injection device 1; 14 is a timing chart for explaining a specific example 13 of the control method of the fuel injection device 1; 16 is a timing chart for explaining a specific example 14 of the control method of the fuel injection device 1; It is a flowchart which shows the procedure of the selection process of the injection pattern of embodiment.

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

<Overview of fuel injection device>
First, the outline | summary of the fuel-injection apparatus 1 which concerns on embodiment is demonstrated.

The fuel injection device 1 is a device that is provided in a self-ignition internal combustion engine EG and injects (supplies) fuel into the combustion chamber CC of the internal combustion engine EG. The internal combustion engine EG is an internal combustion engine provided with a pressure accumulation injection system (common rail injection system). The internal combustion engine EG is a diesel engine provided in, for example, automobiles, ships, railway vehicles, heavy machinery, and the like. For this reason, the fuel is light oil in this example. The internal combustion engine EG may be another self-ignition type internal combustion engine such as a self-ignition type gasoline engine instead of the diesel engine.

Here, a fuel injection device (for example, a conventional fuel injection device) different from the fuel injection device 1 uses, for example, a pressure increasing mechanism to increase the pressure of fuel injected into the combustion chamber of an internal combustion engine equipped with the fuel injection device. When the pressure is increased to a pressure higher than the reference pressure, it is necessary to discharge a part of the high-pressure fuel to the outside in order to operate the pressure increasing mechanism. For this reason, the said apparatus will dissipate a part of energy which the fuel of the said high pressure has as heat energy. That is, the apparatus increases the fuel consumption rate by the amount of energy dissipated as thermal energy.

Therefore, the fuel injection device 1 includes a pressure accumulator that is supplied with fuel from a high pressure source (common rail) that supplies fuel at a predetermined pressure, a first valve that supplies fuel supplied from the high pressure source to the inside of the accumulator, And a second valve that injects fuel supplied to the pressure accumulator from the pressure accumulator into the combustion chamber. The predetermined pressure is a reference pressure in the fuel injection device 1. That is, a fuel injection device (for example, a conventional fuel injection device) different from the fuel injection device 1 can make the pressure of the fuel injected by the fuel injection device higher than the reference pressure in the fuel injection device. On the other hand, the fuel injection device 1 can set the pressure of the fuel injected by the fuel injection device 1 to a pressure equal to or lower than a predetermined pressure that is a reference pressure in the fuel injection device 1. In addition, the fuel injection device 1 has a fuel consumption rate that is lower than that of the fuel injection device because the fuel injection device 1 does not include the pressure increasing mechanism that the fuel injection device (for example, a conventional fuel injection device) different from the fuel injection device 1 has. Low. That is, the fuel injection device 1 does not dissipate part of the energy of the high-pressure fuel as thermal energy, that is, while suppressing an increase in the fuel consumption rate of the internal combustion engine EG, into the combustion chamber CC. The pressure of the fuel to be injected can be changed to a pressure desired by the user. As a result, the fuel injection device 1 can match the temporal change pattern of the pressure of the fuel injected into the combustion chamber CC of the internal combustion engine EG with a pattern desired by the user. These pattern matches may include errors. Here, in the internal combustion engine EG, according to the temporal change pattern, the fuel consumption rate per unit time according to the combustion state in the combustion chamber CC, the amount of noise from the internal combustion engine EG in the drive state, and in the drive state Some or all of the magnitude of vibration of the internal combustion engine EG and the amount of emissions (eg, NOx, HC, CO, other particulate matter) generated from the internal combustion engine EG change. For this reason, in the fuel injection device 1, the user who uses the internal combustion engine EG provided with the fuel injection device 1 increases the fuel consumption rate, increases the noise amount, increases the magnitude of the vibration, and increases the generation amount. When the user feels uncomfortable, the fuel consumption rate can be reduced, the noise level can be reduced, the vibration level can be reduced, the generated volume can be reduced, etc. it can. Below, the structure of the fuel-injection apparatus 1 and the control method of the fuel-injection apparatus 1 are demonstrated in detail.

<Configuration of fuel injection device>
Hereinafter, the configuration of the fuel injection device 1 according to the embodiment will be described.

FIG. 1 is a diagram illustrating an example of the configuration of the fuel injection device 1. The fuel injection device 1 includes a fuel injector 2 and an ECU (Electronic Control Unit) 3 that controls the fuel injector 2. The fuel injection device 1 may be configured without the ECU 3.

The fuel injector 2 is located downstream of the high pressure source 4 in a fuel supply path (not shown) starting from a fuel tank (not shown), and fuel is supplied from the high pressure source 4. The fuel injector 2 injects the fuel supplied from the high pressure source 4 into the combustion chamber CC of the internal combustion engine EG at a pressure corresponding to the control according to the control by the ECU 3. In FIG. 1, in order to emphasize the portion filled with fuel, hatching of the cross section of the fuel injector 2 and the internal combustion engine EG is omitted. Although the number of the fuel injectors 2 shown in FIG. 1 is one, it does not restrict | providing the some fuel injector 2 downstream from the one high voltage | pressure source 4. FIG. For example, the plurality of fuel injectors 2 may have the same specifications. In this case, the fuel injector 2 and the high pressure source 4 may be connected independently of each other, or a part thereof may be shared.
The high pressure source 4 is a common rail provided in the internal combustion engine EG. For example, the fuel supplied from the fuel tank is pressurized by a pressurizing pump (not shown) and supplied to the high pressure source 4. The high pressure source 4 supplies fuel to the fuel injector 2 at a predetermined pressure.

The fuel injector 2 includes, for example, an electric injector 11 and an electric injector 12 that are two electric injectors.

The electric injector 11 includes a fuel supply line 111, a first pressure accumulating portion 112, a nozzle needle 113, a first opening 115 formed in the first pressure accumulating portion 112, and a drive portion A1.
The fuel supply pipe 111 is a pipe formed inside the casing of the electric injector 11. The fuel supply pipe 111 is a pipe through which fuel supplied from the high pressure source 4 at a predetermined pressure passes. Further, the fuel supply pipe 111 is a pipe connecting the high pressure source 4 and the first pressure accumulating unit 112. That is, the first pressure accumulator 112 of the electric injector 11 is connected to the high pressure source 4 by the fuel supply line 111. The fuel supplied from the high pressure source 4 at a predetermined pressure is supplied to the first pressure accumulating unit 112 through the fuel supply line 111.

The first pressure accumulator 112 includes a pressure accumulator formed inside the housing of the electric injector 11. The first pressure accumulating section 112 is formed so that fuel is supplied from the high pressure source 4 to the pressure accumulator and the pressure of the fuel can be maintained. The first pressure accumulating unit 112 includes the first valve 21. The first valve 21 is provided, for example, at a fuel discharge port in the first pressure accumulating unit 112. An electric injector 12 is provided on the downstream side of the electric injector 11 in the fuel supply path. That is, the first valve 21 cuts off the supply of fuel to the electric injector 12 and supplies the fuel supplied from the high pressure source 4 to the electric injector 12. More specifically, when the first valve 21 is open, the fuel accumulated in the first pressure accumulator 112 is supplied to the electric injector 12 with a predetermined pressure. On the other hand, when the first valve 21 is closed, the fuel that is supplied from the high-pressure source 4 at a predetermined pressure is accumulated in the first pressure accumulating unit 112. For example, if fuel is always supplied from the high pressure source 4 to the first pressure accumulating unit 112 at a predetermined pressure, the pressure in the first pressure accumulating unit 112 is always the predetermined pressure except for errors. In addition, when the dynamic effect accompanying the movement of the fuel mentioned later arises, the pressure in the 1st pressure accumulation part 112 may become a pressure higher than the predetermined pressure in the high pressure source 4. In order to simplify the description, a case where the dynamic effect does not occur will be described first.

The first valve 21 is configured by a tip portion 114 </ b> A of the nozzle needle 113 and a first opening 115 formed in the first pressure accumulating portion 112. The nozzle needle 113 includes, for example, a shaft portion formed in a shaft shape at least at a part thereof. A tip portion 114A and a tip portion 114B are provided in the region of the end portion in the extending direction (longitudinal direction) of the nozzle needle 113, respectively. The nozzle needle 113 is arranged with the tip portion 114A facing in the direction in which the fuel flows, and is supported so as to be movable in the extending direction. For example, the tip portion 114A is formed in a tapered shape symmetrical to the axis of the shaft portion. The first opening 115 is provided at an outlet portion where fuel is discharged from the first pressure accumulating portion 112. The first opening 115 is closed or opened by the tip end portion 114 </ b> A by the movement of the nozzle needle 113 in the extending direction. That is, the tip portion 114A of the nozzle needle 113 closes the first opening 115 in a state where the first valve 21 is closed. When the ECU 3 drives the drive unit A1, the nozzle needle 113 is located on the side of the tip 114B along the extending direction, that is, the tip of the tip of the nozzle needle 113 from the tip 114A in the direction along the longitudinal direction. It moves in the direction toward the tip opposite to the portion 114A, and opens the first opening 115. That is, in this case, the first valve 21 is opened. When the drive unit A1 is not driven by the ECU 3, the tip portion 114A of the nozzle needle 113 is pressed against the first opening 115 by the pressure of the fuel supplied through the fuel supply line 111 (for example, a predetermined pressure). Thus, the first opening 115 is closed. Accordingly, the drive unit A1 closes the first valve 21. On the other hand, when the drive unit A1 is driven by the ECU 3, the valve provided in the drive unit A1 supplies the pressure (for example, a predetermined pressure) of the fuel supplied to the second pressure accumulating unit 122 through the fuel supply line 111. By opening A1V, a part of the fuel near the tip 114B is discharged from the valve A1V and decompressed. Along with the pressure reduction, an actuator (command piston) provided in the drive unit A1 moves the nozzle needle 113 in the direction of the distal end portion 114B to open the first opening 115. As a result, the drive unit A1 opens the first valve 21. In addition, the electric injector 11 was raised to said predetermined pressure by making the flow area of the 1st valve 21 of the open state into an area equal to or more than the flow area of the fuel supply line 111. Loss of energy stored in the fuel can be reduced. The fuel discharged from the valve A1V is returned to a fuel tank (not shown). Further, the structure and operation for changing the state of the first valve 21 to either the opened state or the closed state may be a known structure and operation, and a structure and operation to be developed in the future. Therefore, further detailed description is omitted. In addition, although said drive part A1 showed valve A1V which is an electromagnetic valve as an example, it may replace with this and may be provided with the piezo element (laminated piezoelectric element). In that case, the description of supplying the drive current to the valve A1V may be replaced with applying a drive voltage to the piezo element.

The electric injector 12 includes a fuel supply line 121, a second pressure accumulating portion 122, a nozzle needle 123, a second opening 125 formed in the second pressure accumulating portion 122, and a driving portion A2.

The fuel supply pipe 121 is a pipe formed inside the casing of the electric injector 12. The fuel supply pipe 121 is a pipe through which the fuel supplied from the first pressure accumulator 112 of the electric injector 11 with a predetermined pressure passes. The fuel supply pipe 121 is a pipe that connects the first opening 115 of the electric injector 12 and the second pressure accumulator 122. The second pressure accumulating portion 122 of the electric injector 12 is connected to the first pressure accumulating portion 112 of the electric injector 11 through the fuel supply pipe 121. The fuel supplied at a predetermined pressure from the first pressure accumulator 112 is supplied to the second pressure accumulator 122 through the fuel supply line 121 when the first valve 21 is open.

The second pressure accumulator 122 includes a pressure accumulator formed inside the housing of the electric injector 12. The second pressure accumulator 122 is formed so that fuel is supplied to the accumulator from the first pressure accumulator 112 of the electric injector 11 and the pressure of the fuel can be held. The combination of the fuel supply pipe 121 and the second pressure accumulating portion 122 (or the second pressure accumulating portion 122) is an example of the pressure accumulating portion in the claims. Hereinafter, for convenience of explanation, the internal pressures of the fuel supply pipe 121 and the second pressure accumulator 122 will be referred to as the pressure in the second pressure accumulator 122. The fuel injection device 1 may be configured not to include the fuel supply pipe 121. In this case, in the fuel injection device 1, for example, the first pressure accumulation unit 112 and the second pressure accumulation unit 122 are adjacent to each other with the first valve 21 interposed therebetween, and are partitioned by the first valve 21. The second pressure accumulating unit 122 includes the second valve 22. The second valve 22 is provided, for example, at a fuel discharge port in the second pressure accumulating unit 122. A combustion chamber CC of the internal combustion engine EG is provided on the downstream side of the electric injector 12 in the fuel supply path. That is, the second valve 22 shuts off the supply of fuel to the combustion chamber CC and injects the fuel supplied to the second pressure accumulating portion 122 from the second pressure accumulating portion 122 into the combustion chamber CC. More specifically, when the second valve 22 is open, the fuel accumulated in the second pressure accumulating portion 122 is injected into the combustion chamber CC according to the pressure in the second pressure accumulating portion 122. A state in which the first valve 21 is open and the second valve 22 is closed is referred to as a first state. In the first state, the pressure is increased to, for example, a predetermined pressure that is the pressure of the high pressure source 4 at the maximum. The state in which the first valve 21 is closed and the second valve 22 is open is referred to as a second state. In the case of the second state, the pressure is reduced according to the elapsed time after the second valve 22 is opened. The amount of change in the pressure per unit time in this case is represented by the following formula (1).

ΔP = −K (q / V) (1)

ΔP represents the amount of change in pressure in the second pressure accumulating unit 122 per unit time in the second state. K represents the volume elastic modulus of the fuel accumulated in the second pressure accumulating unit 122. Further, q represents a fuel injection amount that is an amount of fuel injected from the second pressure accumulating unit 122 into the combustion chamber CC per unit time in the second state. Further, V represents the total volume of the volume of the fuel supply pipe 121 and the volume of the second pressure accumulating unit 122. That is, the amount of change in pressure per unit time in the second pressure accumulator 122 is inversely proportional to the volume V of the second pressure accumulator 122 and proportional to the fuel injection amount q injected from the second pressure accumulator 122 per unit time. To do.

Here, if the amount by which the pressure of the second pressure accumulator 122 decreases per unit time in the second state is greater than the amount by which the pressure of the second pressure accumulator 122 increases per unit time in the first state, In the state, the pressure of the second accumulator 122 decreases. The third state is a state in which the first valve 21 is open and the second valve 22 is open. More specifically, when the change amount ΔP of the pressure in the second pressure accumulator 122 in the second state is larger than the change amount of the pressure in the second pressure accumulator 122 in the first state, the second pressure accumulation in the third state. The amount of change in pressure in the portion 122 is greater than the amount of change ΔP by the difference between the amount of change in pressure ΔP in the second pressure accumulator 122 in the second state and the amount of change in pressure in the second pressure accumulator 122 in the first state. Becomes smaller.

Further, when the amount by which the pressure of the second pressure accumulator 122 decreases per unit time in the second state is smaller than the amount by which the pressure of the second pressure accumulator 122 increases in unit time in the first state, the third state In this case, the pressure of the second pressure accumulating portion 122 increases. More specifically, when the amount of change ΔP in the second pressure accumulator 122 in the second state is smaller than the amount of change in the pressure in the second accumulator 122 in the first state, the second pressure accumulation in the third state. The pressure in the unit 122 is increased every time the unit time elapses by the difference between the pressure change amount ΔP in the second pressure storage unit 122 in the second state and the pressure change amount in the second pressure storage unit 122 in the first state. growing.

Hereinafter, as an example, a case will be described in which the amount of change ΔP in the pressure in the second pressure accumulator 122 in the second state is smaller than the amount of change in the pressure in the second pressure accumulator 122 in the first state. That is, in this example, the amount by which the pressure of the second pressure accumulator 122 decreases per unit time in the second state is smaller than the amount by which the pressure of the second pressure accumulator 122 increases per unit time in the first state. For this reason, the fuel injection device 1 sets the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC within a range equal to or lower than a predetermined pressure according to the open / close states of the first valve 21 and the second valve 22. The pressure can be changed to an arbitrary pressure.

The second valve 22 is configured by a tip end portion 124 </ b> A of the nozzle needle 123 and a second opening 125 formed in the second pressure accumulating portion 122. The nozzle needle 123 includes, for example, a shaft portion formed in an axial shape at least at a part thereof. A tip portion 124A and a tip portion 124B are provided in the region of the end portion in the extending direction (longitudinal direction) of the nozzle needle 123, respectively. The nozzle needle 123 is arranged with the tip end 124A facing in the direction in which the fuel flows, and is supported so as to be movable in the extending direction. For example, the tip portion 124A is formed in a tapered shape symmetrical to the axis of the shaft portion. The second opening 125 is provided at an outlet portion where fuel is discharged from the second pressure accumulating portion 122. The second opening 125 is closed or opened by the tip end 124 </ b> A by the movement of the nozzle needle 123 in the extending direction. That is, the tip end portion 124A of the nozzle needle 123 closes the second opening 125 in a state where the second valve 22 is closed. When the ECU 3 drives the drive unit A2, the nozzle needle 123 is located on the tip end 124B side in the extending direction, that is, the tip of the tip of the nozzle needle 123 from the tip portion 124A in the direction along the longitudinal direction. It moves in the direction toward the tip opposite to the portion 124A, and opens the second opening 125. That is, in this case, the second valve 22 is opened. When the drive unit A2 is not driven by the ECU 3, the tip portion 124A of the nozzle needle 123 is pressed against the second opening 125 by the pressure of the fuel supplied through the fuel supply line 121 (for example, a predetermined pressure). Then, the second opening 125 is closed. As a result, the drive unit A2 closes the second valve 22. On the other hand, when the drive unit A2 is driven by the ECU 3, a part of the fuel in the vicinity of the front end portion 124B among the fuel supplied to the second pressure accumulating unit 122 through the fuel supply pipe 121 is provided in the drive unit A2. By opening the valve A2V, the fuel is discharged from the valve A2V, and the fuel in the vicinity of the tip 124B is decompressed. Along with the pressure reduction, an actuator (command piston) provided in the drive unit A2 moves the nozzle needle 123 in the direction of the tip end 124B and opens the second opening 125. As a result, the drive unit A2 opens the second valve 22. The fuel discharged from the valve A2V is returned to a fuel tank (not shown). The structure and operation for changing the state of the second valve 22 to either the open state or the closed state may be a known structure and operation, and a structure and operation to be developed in the future. Therefore, further detailed description is omitted. In addition, although said drive part A2 has shown valve A2V which is a solenoid valve as an example, it may replace with this and may be provided with the piezo element. In that case, the description of supplying the drive current to the valve A2V may be replaced with applying a drive voltage to the piezo element.

<Logical structure of fuel injection device>
Hereinafter, the logical structure of the fuel injection device 1 will be described with reference to FIG. The configuration of the fuel injection device 1 is not limited to the configuration described in FIG. Therefore, here, a logical structure in which essential components that the fuel injection device 1 should have in order to realize each of the first state to the third state will be described. FIG. 2 is a diagram illustrating an example of a logical structure of the fuel injection device 1.

FIG. 2 shows the high-pressure source PR1, the first valve V1, the pressure accumulating part PR2, the second valve V2, and the injection part CR. The high pressure source PR1, the first valve V1, the pressure accumulator PR2, the second valve V2, and the injector CR are respectively a high pressure source PR1, a first valve V1, a pressure accumulator PR2, a second valve V2, and an injector CR. Are logically connected in this order. That is, the logical structure of the fuel injection device 1 is that the high pressure source PR1, the first valve V1, the pressure accumulator PR2, the second valve V2, and the injector CR are the high pressure source PR1, the first valve V1, It shows that the pressure storage part PR2, the second valve V2, and the injection part CR are logically connected in this order.

The high-pressure source PR1 is a common rail that supplies fuel to the accumulator PR2 with a predetermined pressure. When the first valve V1 is opened while the second valve V2 is closed, the fuel supplied at a predetermined pressure from the high pressure source PR1 is accumulated in the pressure accumulator PR2 through the first valve V1. At this time, the pressure in the pressure accumulating part PR2 increases according to the time during which the first valve V1 is open, for example, reaches a predetermined pressure at the maximum. In addition, when the second valve V2 is opened while the first valve V1 is closed, the fuel accumulated in the pressure accumulator PR2 is a pressure corresponding to the elapsed time since the second valve V2 opened. It is injected from the injection part CR into the combustion chamber CC by the pressure in the pressure accumulating part PR2. That is, the fuel injection device 1 is formed by a combination of members corresponding to each of the high pressure source PR1, the first valve V1, the pressure accumulating portion PR2, the second valve V2, and the injection portion CR. When the logical structure of 1 matches the logical structure shown in FIG. 2, the conditions regarding the open state or the closed state of the first valve V1 and the second valve V2 are set as the logical structure described above. In combination, the first state to the third state described above can be realized.

Here, in the example shown in FIG. 1, the member corresponding to the high pressure source PR <b> 1 is the high pressure source 4. In the example, the member corresponding to the first valve V <b> 1 is the first valve 21. In this example, the member corresponding to the pressure accumulating portion PR2 is a combination of the fuel supply pipe 121 and the second pressure accumulating portion 122. In the example, the member corresponding to the second valve V <b> 2 is the second valve 22. In the example, the member corresponding to the injection part CR is the second opening 125. As described above, by associating each member, it is possible to simplify the processing required for analyzing the pressure fluctuation of each part.

<Configuration of ECU>
Hereinafter, the configuration of the ECU 3 will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of a hardware configuration of the ECU 3. The ECU 3 includes, for example, a CPU (Central Processing Unit) 31, a storage unit 32, a first valve drive circuit 33, and a second valve drive circuit 34. These components are communicably connected to each other via a bus Bus. Further, the ECU 3 may include a communication unit for communicating with other ECUs.

The CPU 31 includes a processor that executes a software program (hereinafter referred to as a program), and reads and executes various programs stored in the storage unit 32 or the like.
The storage unit 32 includes, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a ROM (Read-Only Memory), a RAM (Random Access Memory), and the like. The storage unit 32 stores various information processed by the ECU 3.

The first valve drive circuit 33 supplies a drive current for driving the drive unit A1 that opens and closes the first valve 21 to the drive unit A1.
The second valve drive circuit 34 supplies a drive current for driving the drive unit A2 that opens and closes the second valve 22 to the drive unit A2.

<Functional configuration of ECU>
Hereinafter, the functional configuration of the ECU 3 will be described with reference to FIG. FIG. 4 is a diagram illustrating an example of a functional configuration of the ECU 3. The ECU 3 includes a storage unit 32, a first valve drive circuit 33, a second valve drive circuit 34, and a control unit 36.

The control unit 36 controls the first valve drive circuit 33 to drive the drive unit A1, and changes the state of the first valve 21 to an open state or a closed state according to the timing stored in advance in the storage unit 32. To do. In addition, the control unit 36 controls the second valve drive circuit 34 to drive the drive unit A1, and the state of the second valve 22 is opened or closed according to the timing stored in advance in the storage unit 32. Put it in a state. The control unit 36 is realized by the CPU 31 executing various programs stored in the storage unit 32, for example. The control unit 36 may be a hardware function unit such as an LSI (Large Scale Integration) or an ASIC (Application Specific Integrated Circuit).

<Control method of fuel injection device>
Hereinafter, specific examples of the control method of the fuel injection device 1 will be described with reference to FIGS. Hereinafter, for convenience of explanation, the control unit 36 controls the first valve drive circuit 33 with the second valve 22 opened, and drives the drive unit A1 to open the first valve 21. This is referred to as pressure increase control, and control in which the control unit 36 controls the second valve drive circuit 34 while the first valve 21 is closed and drives the drive unit A2 to open the second valve 22 is referred to as pressure reduction control. I will explain. In the following, as an example, the first valve drive circuit 33 supplies the drive current A0 to the drive unit A1 to open the first valve 21, and the second valve drive circuit 34 supplies the drive current A0 to the drive unit A2. A case where the second valve 22 is opened will be described. That is, the drive unit A1 closes the first valve 21 when the supply of the drive current A0 from the first valve drive circuit 33 stops, and the drive unit A2 closes the second valve 22 when the supply of the drive current A0 stops.

FIG. 5 is a timing chart for explaining a specific example 1 of the control method of the fuel injection device 1. The timing chart shown in FIG. 5 includes four graphs, graphs CH11 to CH14. Each horizontal axis of the graphs CH11 to CH14 represents time. Further, the vertical axis of the graph CH11 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. Further, the vertical axis of the graph CH12 represents the pressure in the second pressure accumulating unit 122. The vertical axis of the graph CH13 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. The vertical axis of the graph CH14 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Also, time t11 in the graphs CH11 to CH14 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. Further, time t12 in the graphs CH11 to CH14 represents the time when the second valve 22 is opened when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2. Further, time t13 in the graphs CH11 to CH14 represents a time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t11 is a time before time t12, and time t12 is a time before time t13.

In the example shown in FIG. 5, the fuel injection device 1 realizes the first state described above in the eleventh time zone that is the time zone from time t11 to time t12. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is 0 in the time zone before time t11. In the eleventh time zone, the pressure in the second pressure accumulator 122 is increased according to the elapsed time from the time t11. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In this example, the pressure is increased from 0 to a predetermined pressure P0 in the eleventh time zone. The time required to increase the pressure in the second pressure accumulating section 122 from 0 to the predetermined pressure P0 in the first state can be examined by experiment or the like, and can be estimated by calculation based on fluid dynamics or the like. is there. Based on the result of the experiment or the calculation, the user can determine the length of the eleventh time zone as a time longer than the time.

Next, in the twelfth time period that is the time period from time t12 to time t13, the fuel injection device 1 realizes the above-described third state by performing pressure increase control. In the eleventh time zone, the pressure in the second pressure accumulator 122 is increased to the predetermined pressure P0, and the first valve 21 remains open in the twelfth time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while keeping the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC at the predetermined pressure P0. Then, since the fuel injection device 1 closes the second valve 22 at time t13, the fuel injection from the second pressure accumulator 122 into the combustion chamber CC stops and is injected from the second pressure accumulator 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t13. On the other hand, since the fuel injection device 1 keeps the first valve 21 open during the time period, the pressure in the second pressure accumulator 122 is kept at the predetermined pressure P0.

With the control method represented by the timing chart shown in FIG. 5, the fuel injection device 1 displays the pattern of temporal change in the pressure of the fuel injected into the combustion chamber CC while suppressing an increase in the fuel consumption rate. The fuel injection device different from 1 (for example, a conventional fuel injection device) can easily match the temporal change pattern of the pressure of the fuel injected into the combustion chamber of the internal combustion engine including the fuel injection device. Hereinafter, for convenience of explanation, the pattern of temporal change in the pressure of the fuel injected by the fuel injection device 1 into the combustion chamber CC as shown in FIG. 5 will be referred to as a rectangular pattern.

FIG. 6 is a timing chart for explaining a specific example 2 of the control method of the fuel injection device 1. The timing chart shown in FIG. 6 includes four graphs of graphs CH21 to CH24. Each horizontal axis of the graphs CH21 to CH24 represents time. In addition, the vertical axis of the graph CH21 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. The vertical axis of the graph CH22 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH23 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. The vertical axis of the graph CH24 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Also, time t21 in the graphs CH21 to CH24 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. Also, time t22 in the graphs CH21 to CH24 represents the time when the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped and the first valve 21 is closed. Further, time t23 in the graphs CH21 to CH24 represents the time when the second valve drive circuit 34 supplies the drive current to the drive unit A2 and the second valve 22 is opened. Also, time t24 in the graphs CH21 to CH24 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t21 is a time before time t22, time t22 is a time before time t23, and time t23 is a time before time t24.

In the example shown in FIG. 6, the fuel injection device 1 realizes the first state described above in the 21st time zone that is the time zone from time t21 to time t22. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P11 in the time zone before time t21. The pressure P11 is a pressure lower than the predetermined pressure P0. In the 21st time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t21. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In this example, the pressure is increased from the pressure P11 to the predetermined pressure P0 in the 21st time zone. The length of the 21st time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 22nd time zone which is the time zone from time t22 to time t23, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulating portion 122 is increased from the pressure P11 to the predetermined pressure P0 in the 21st time zone. For these reasons, in the 22nd time zone, the pressure in the second pressure accumulating portion 122 is kept at the predetermined pressure P0.

Next, in the 23rd time zone which is the time zone from time t23 to time t24, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is maintained at the predetermined pressure P0 in the 22nd time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC in the 23rd time zone. The fuel is injected from the second pressure accumulating section 122 into the combustion chamber CC while reducing the pressure from the predetermined pressure P0 to the pressure P11 corresponding to the length of the 23rd time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P11, that is, the length of the 23rd time zone, is the predetermined pressure P0, the pressure P11, and the above-described equation (1). Can be calculated based on Then, since the fuel injection device 1 closes the second valve 22 at time t24, the fuel injection from the second pressure accumulating portion 122 into the combustion chamber CC stops and is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t24. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P11.

With the control method represented by the timing chart shown in FIG. 6, the fuel injection device 1 allows the user to select a temporal change pattern of the pressure of the fuel injected into the combustion chamber CC while suppressing an increase in the fuel consumption rate. Among the patterns to be matched, it can be matched with the inverse delta pattern. The inverse delta pattern is the pattern shown in FIG. 6 and the time variation pattern of the pressure of the fuel injected by the fuel injection device 1 into the combustion chamber CC. That is, the reverse delta pattern indicates that the pressure of the fuel injected into the combustion chamber CC by the fuel injection device 1 is the period during which the fuel injection device 1 is injecting fuel (in the example shown in FIG. In the band), the pattern monotonously decreases from the predetermined pressure P0 to the pressure P11 with the passage of time. In the reverse delta pattern, the fuel injected from the fuel injection device 1 into the combustion chamber CC is injected almost uniformly into the combustion chamber CC in the 23rd time zone. This is because the speed of the fuel injected from the fuel injection device 1 into the combustion chamber CC becomes slower with the passage of time (that is, with a decrease in the pressure in the second pressure accumulating portion 122) in the 23rd time zone. . As a result, the fuel injection device 1 causes the fuel flame to collide with the inner wall of the combustion chamber CC by the collision of the fuel with the inner wall of the fuel chamber CC due to excessive fuel spray or the collision of the fuel with the inner wall of the fuel chamber CC due to the flame after ignition. Cooling loss caused by being cooled can be suppressed. Here, the fuel flame is a flame generated by burning the fuel.

FIG. 7 is a timing chart for explaining a specific example 3 of the control method of the fuel injection device 1. The timing chart shown in FIG. 7 includes four graphs of graphs CH31 to CH34. Each horizontal axis of the graphs CH31 to CH34 represents time. In addition, the vertical axis of the graph CH31 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. Further, the vertical axis of the graph CH32 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH33 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. Further, the vertical axis of the graph CH34 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Also, at time t31 in the graphs CH31 to CH34, the first valve drive circuit 33 supplies the drive current to the drive unit A1, and the second valve drive circuit 34 supplies the drive current to the drive unit A2, and the first valve The time when both 21 and the second valve 22 are opened is shown. In addition, each of time t33, time t35, and time t37 in the graphs CH31 to CH34 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. In addition, at time t32, time t34, time t36, and time t38 in the graphs CH31 to CH34, the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 is closed. Represents the time. Also, time t39 in the graphs CH31 to CH34 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t31 is a time before time t32, time t32 is a time before time t33, time t33 is a time before time t34, and time t35 is a time. It is a time before t36, time t36 is a time before time t37, time t37 is a time before time t38, and time t38 is a time before time t39. . Further, each of the pressure P21, the pressure P22, the pressure P23, the pressure P24, and the pressure P25 in the graph CH32 and the graph CH34 is a pressure lower than the predetermined pressure P0. The pressure P21 is lower than the pressure P22, the pressure P22 is lower than the pressure P23, the pressure P23 is lower than the pressure P24, and the pressure P24 is lower than the pressure P25. It is a pressure and the pressure P25 is a pressure lower than the pressure P26.

In the example shown in FIG. 7, the fuel injection device 1 realizes the third state by performing the pressure increase control in the 31st time zone that is the time zone from time t31 to time t32. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P21 in the time zone before time t31. In the 31st time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P21 to the pressure P23 corresponding to the length of the 31st time zone, and from the second pressure accumulating portion 122 to the combustion chamber CC. Fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P21 at the time t31, and is increased from the pressure P21 to the pressure P23 in the 31st time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P21 to the pressure P23, that is, the length of the 31st time zone is the pressure P21, the pressure P23, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 32nd time slot | zone which is a time slot | zone of the time t32-the time t33, the fuel injection apparatus 1 implement | achieves the 2nd state by performing pressure reduction control. For this reason, in the 32nd time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulator 122 from the pressure P23 to the pressure P22 corresponding to the length of the 32nd time zone, from the second pressure accumulator 122. Fuel is injected into the combustion chamber CC. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the 32nd time zone is the pressure P23 at time t32 and is reduced from the pressure P23 to the pressure P22 in the 32nd time zone. . The time required for the pressure in the second accumulator 122 to be reduced from the pressure P23 to the pressure P22, that is, the length of the 32nd time zone is based on the pressure P23, the pressure P22, and the above-described equation (1). Can be calculated.

Next, in the 33rd time zone which is the time zone from time t33 to time t34, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 33rd time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P22 to the pressure P25 corresponding to the length of the 33rd time zone, and then from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P22 at the time t33, and is increased from the pressure P22 to the pressure P25 in the 33rd time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P22 to the pressure P25, that is, the length of the 33rd time zone is the pressure P22, the pressure P25, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 34th time zone which is the time zone from time t34 to time t35, the fuel injection device 1 realizes the second state by performing pressure reduction control. For this reason, in the 34th time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulation unit 122 from the pressure P25 to the pressure P24 corresponding to the length of the 34th time zone. Fuel is injected into the combustion chamber CC. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the 34th time zone is the pressure P25 at time t34, and is reduced from the pressure P25 to the pressure P24 in the 34th time zone. . The time required for the pressure in the second pressure accumulating section 122 to be reduced from the pressure P25 to the pressure P24, that is, the length of the 34th time zone is based on the pressure P25, the pressure P24, and the above-described equation (1). Can be calculated.

Next, in the 35th time zone which is the time zone from time t35 to time t36, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 35th time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC while increasing the pressure in the second pressure accumulator 122 from the pressure P24 to the predetermined pressure P0. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P24 at time t35, and is increased from the pressure P24 to the predetermined pressure P0 in the 35th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P24 to the predetermined pressure P0, that is, the length of the 35th time zone, is the pressure P24, the predetermined pressure P0, and the above formula (1). And a method for determining the length of the eleventh time zone.

Next, in the 36th time zone which is the time zone from time t36 to time t37, the fuel injection device 1 realizes the second state by performing pressure reduction control. Therefore, in the 36th time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulation portion 122 from the predetermined pressure P0 to the pressure P26 corresponding to the length of the 36th time zone, while the second pressure accumulation portion 122. To inject the fuel into the combustion chamber CC. As a result, the pressure of the fuel injected into the combustion chamber CC from the second pressure accumulator 122 in the 34th time zone is the predetermined pressure P0 at time t36, and is reduced from the predetermined pressure P0 to the pressure P26 in the 36th time zone. Is done. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P26, that is, the length of the 36th time zone, is the predetermined pressure P0, the pressure P26, and the above-described equation (1). Can be calculated based on

Next, in the 37th time zone which is the time zone from time t37 to time t38, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 37th time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC while increasing the pressure in the second pressure accumulator 122 from the pressure P26 to the predetermined pressure P0. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P26 at time t37, and is increased from the pressure P26 to the predetermined pressure P0 in the 37th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P26 to the predetermined pressure P0, that is, the length of the 37th time zone, is the pressure P26, the predetermined pressure P0, and the above-described formula (1). And a method for determining the length of the eleventh time zone.

Next, in the 38th time zone which is the time zone from time t38 to time t39, the fuel injection device 1 realizes the second state by performing pressure reduction control. For this reason, in the 38th time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulation portion 122 from the predetermined pressure P0 to the pressure P21 corresponding to the length of the 38th time zone, while the second pressure accumulation portion 122. To inject the fuel into the combustion chamber CC. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the 38th time zone is the predetermined pressure P0 at time t38, and is reduced from the predetermined pressure P0 to the pressure P21 in the 38th time zone. Is done. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P21, that is, the length of the 38th time zone, is the predetermined pressure P0, the pressure P21, and the above-described equation (1). Can be calculated based on

Then, since the fuel injection device 1 closes the second valve 22 at time t39, the fuel injection from the second pressure accumulator 122 into the combustion chamber CC stops and is injected from the second pressure accumulator 122 into the combustion chamber CC. The fuel pressure becomes zero in the time zone after time t39. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P21. In addition, the pressure of the fuel injected into the combustion chamber CC from the second pressure accumulating portion 122 does not include the pressure due to the compression process of the combustion chamber CC. When the pressure of the fuel injected into the combustion chamber CC from the second pressure accumulator 122 is 0, for example, it corresponds to a case where the fuel is injected into an open state.

With the control method represented by the timing chart shown in FIG. 7, the fuel injection device 1 allows the user to select a temporal change pattern of the pressure of the fuel injected into the combustion chamber CC while suppressing an increase in the fuel consumption rate. Among the patterns to be matched, it can be made to match the delta pattern. The delta pattern is a pattern shown in FIG. 7 and a temporal change pattern of the pressure of fuel injected by the fuel injection device 1 into the combustion chamber CC. That is, in the delta pattern, the pressure of the fuel injected into the combustion chamber CC by the fuel injection device 1 is a period during which the fuel injection device 1 is injecting fuel (in the example shown in FIG. 7, time t31 to time It is a pattern that increases almost monotonically from the pressure P21 to the predetermined pressure P0 with the passage of time in the time zone t39). In the delta pattern, the fuel injected from the fuel injection device 1 into the combustion chamber CC is caused by a higher pressure in the latter period in the period than in the period in which the fuel injection apparatus 1 injects the fuel into the combustion chamber CC. Be injected. For this reason, the fuel injection device 1 can atomize the fuel injected into the combustion chamber CC, and can cause disturbed combustion of the fuel in the combustion chamber CC. As a result, the fuel injection device 1 can reduce the amount of noise of the internal combustion engine EG in the drive state, and can further reduce the amount of emissions generated from the internal combustion engine EG.

FIG. 8 is a timing chart for explaining a specific example 4 of the control method of the fuel injection device 1. The timing chart shown in FIG. 8 includes four graphs, graphs CH41 to CH44. Each horizontal axis of the graphs CH41 to CH44 represents time. In addition, the vertical axis of the graph CH41 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. Further, the vertical axis of the graph CH <b> 42 represents the pressure in the second pressure accumulating unit 122. The vertical axis of the graph CH43 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. The vertical axis of the graph CH44 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Each of time t41 and time t44 in the graphs CH41 to CH44 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. Each of times t42 and t45 in the graphs CH41 to CH44 represents a time when the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped and the first valve 21 is closed. Also, time t43 in the graphs CH41 to CH44 represents the time when the second valve drive circuit 34 supplies the drive current to the drive unit A2 and the second valve 22 is opened. Also, time t46 in the graphs CH41 to CH44 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t41 is a time before time t42, time t42 is a time before time t43, time t43 is a time before time t44, and time t45 is a time. Time before t46. Further, the pressure P31 in the graph CH42 and the graph CH44 is a pressure lower than the predetermined pressure P0.

In the example shown in FIG. 8, the fuel injection device 1 realizes the first state in the 41st time zone that is the time zone from time t41 to time t42. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P31 in the time zone before time t41. In the 41st time zone, the pressure in the second pressure accumulator 122 is increased according to the elapsed time from time t41. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In this example, the pressure is increased from the pressure P31 to the predetermined pressure P0 in the 41st time zone. The length of the 41st time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in a 42nd time zone that is a time zone from time t42 to time t43, the fuel injection device 1 closes both the first valve 21 and the second valve 22. In the 41st time zone, the pressure in the second pressure accumulating portion 122 is increased from the pressure P31 to the predetermined pressure P0. For these reasons, in the 42nd time zone, the pressure in the second pressure accumulator 122 is kept at the predetermined pressure P0.

Next, in a 43rd time zone that is a time zone from time t43 to time t44, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 was maintained at the predetermined pressure P0 in the 42nd time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC in the 43rd time zone. The fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC while reducing the pressure from a predetermined pressure P0 to a pressure P31 corresponding to the length of the 43rd time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P31, that is, the length of the 43rd time zone, is the predetermined pressure P0, the pressure P31, and the above-described equation (1). Can be calculated based on

Next, in the 44th time zone that is the time zone from time t44 to time t45, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 44th time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC while increasing the pressure in the second pressure accumulator 122 from the pressure P31 to the predetermined pressure P0. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P31 at time t44, and is increased from the pressure P31 to the predetermined pressure P0 in the 44th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P31 to the predetermined pressure P0, that is, the length of the 44th time zone, is the pressure P31, the predetermined pressure P0, and the above-described formula (1). And a method for determining the length of the eleventh time zone.

Next, in the 45th time zone that is the time zone from time t45 to time t46, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 is the predetermined pressure P0 at time t45, the fuel injection device 1 sets the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC at the predetermined pressure in the 45th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure from P0 to a pressure P31 corresponding to the length of the 45th time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P31, that is, the length of the 45th time zone, is the predetermined pressure P0, the pressure P31, and the above-described equation (1). Can be calculated based on

Then, since the fuel injection device 1 closes the second valve 22 at time t46, the fuel injection from the second pressure accumulating portion 122 into the combustion chamber CC stops and is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t46. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P31.

With the control method represented by the timing chart shown in FIG. 8, the fuel injection device 1 allows the user to select a temporal change pattern of the pressure of the fuel injected into the combustion chamber CC while suppressing an increase in the fuel consumption rate. It can be made to coincide with the concave pattern among the patterns to be performed. The concave pattern is a pattern shown in FIG. 8 and a pattern of temporal change in the pressure of the fuel injected by the fuel injection device 1 into the combustion chamber CC. That is, the concave pattern indicates a period during which the pressure of the fuel injected into the combustion chamber CC by the fuel injection device 1 is injecting the fuel (in the example shown in FIG. 8, time t43 to time t46). In this time zone, the pattern decreases monotonously from the predetermined pressure P0 to the pressure P31 with time, and then increases monotonically from the pressure P31 to the predetermined pressure P0. In the concave pattern, the fuel injected from the fuel injection device 1 into the combustion chamber CC is injected almost uniformly into the combustion chamber CC in the 43rd time zone, and again from the pressure P31 after the 44th time zone. Is also injected by a predetermined pressure P0 which is a high pressure. As a result, the fuel injection device 1 can cause disturbed combustion of the fuel in the combustion chamber CC later in the period than in the previous period in which the fuel injection device 1 is injecting fuel into the combustion chamber CC. it can. As a result, the fuel injection device 1 can reduce the amount of emissions generated from the internal combustion engine EG. That is, the control method represented by the timing chart shown in FIG. 8 is a control method that combines the control method represented by the timing chart shown in FIG. 6 and the control method represented by the timing chart shown in FIG. Therefore, the fuel injection device 1 can obtain both the effects described in FIGS. 6 and 7.

FIG. 9 is a timing chart for explaining a specific example 5 of the control method of the fuel injection device 1. The timing chart shown in FIG. 9 includes four graphs of graphs CH51 to CH54. Each horizontal axis of the graphs CH51 to CH54 represents time. The vertical axis of the graph CH51 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. In addition, the vertical axis of the graph CH52 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH53 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. Further, the vertical axis of the graph CH54 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. In addition, time t51 in the graphs CH51 to CH54 represents the time when the second valve drive circuit 34 supplies the drive current to the drive unit A2 and the second valve 22 is opened. In addition, each of time t52, time t54, and time t56 in the graphs CH51 to CH54 represents a time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. Further, each of time t53, time t55, and time t57 in the graphs CH51 to CH54 represents the time when the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped and the first valve 21 is closed. . Also, time t58 in the graphs CH51 to CH54 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t51 is a time before time t52, time t52 is a time before time t53, time t53 is a time before time t54, and time t54 is a time. Time before t55, time t55 is a time before time t56, time t56 is a time before time t57, and time t57 is a time before time t58. . Further, each of the pressure P41, the pressure P42, the pressure P43, the pressure P44, the pressure P45, and the pressure P46 in the graph CH52 and the graph CH54 is a pressure lower than the predetermined pressure P0. The pressure P41 is lower than the pressure P42, the pressure P42 is lower than the pressure P43, the pressure P43 is lower than the pressure P44, and the pressure P44 is lower than the pressure P45. The pressure P45 is a pressure lower than the pressure P46.

In the example shown in FIG. 9, the fuel injection device 1 realizes the second state by performing pressure reduction control in the 51st time zone that is the time zone from time t51 to time t52. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P42 in the time zone before time t51. In the 51st time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulating portion 122 from the pressure P42 to the pressure P41 corresponding to the length of the 51st time zone, and then from the second pressure accumulating portion 122 to the combustion chamber CC. The fuel is injected into the inside. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the 51st time zone is the pressure P42 at time t51, and is reduced from the pressure P42 to the pressure P41 in the 51st time zone. . The time required for the pressure in the second accumulator 122 to be reduced from the pressure P42 to the pressure P41, that is, the length of the 51st time zone is based on the pressure P42, the pressure P41, and the above-described equation (1). Can be calculated.

Next, in the 52nd time zone which is the time zone from time t52 to time t53, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 52nd time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P41 to the pressure P44 corresponding to the length of the 52nd time zone, and from the second pressure accumulating portion 122 to the combustion chamber CC. The fuel is injected into the inside. Accordingly, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P41 at time t52, and is increased from the pressure P41 to the pressure P44 in the 52nd time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P41 to the pressure P44, that is, the length of the 52nd time zone, is the pressure P41, the pressure P44, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 53rd time zone that is the time zone from time t53 to time t54, the fuel injection device 1 realizes the second state by performing pressure reduction control. For this reason, in the 53rd time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulation portion 122 from the pressure P44 to the pressure P43 corresponding to the length of the 53rd time zone. Fuel is injected into the combustion chamber CC. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the 53rd time zone is the pressure P44 at time t53, and is reduced from the pressure P44 to the pressure P43 in the 53rd time zone. . The time required for the pressure in the second accumulator 122 to be reduced from the pressure P44 to the pressure P43, that is, the length of the 53rd time zone is based on the pressure P44, the pressure P43, and the above-described equation (1). Can be calculated.

Next, in the 54th time zone which is the time zone from time t54 to time t55, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 54th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P43 to the pressure P46 corresponding to the length of the 54th time zone, and then from the second pressure accumulating portion 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P43 at time t54, and is increased from the pressure P43 to the pressure P46 in the 54th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P43 to the pressure P46, that is, the length of the 54th time zone, is the pressure P43, the pressure P46, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 55th time zone that is the time zone from time t55 to time t56, the fuel injection device 1 realizes the second state by performing pressure reduction control. For this reason, in the 55th time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulation portion 122 from the pressure P46 to the pressure P45 corresponding to the length of the 55th time zone. Fuel is injected into the combustion chamber CC. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the 55th time zone is the pressure P46 at time t55, and is reduced from the pressure P46 to the pressure P45 in the 55th time zone. . The time required for the pressure in the second accumulator 122 to be reduced from the pressure P46 to the pressure P45, that is, the length of the 55th time zone is based on the pressure P46, the pressure P45, and the above-described equation (1). Can be calculated.

Next, in the 56th time zone which is the time zone from time t56 to time t57, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 56th time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC while increasing the pressure in the second pressure accumulator 122 from the pressure P45 to the predetermined pressure P0. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P45 at time t56, and is increased from the pressure P45 to the predetermined pressure P0 in the 56th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P45 to the predetermined pressure P0, that is, the length of the 56th time zone, is the pressure P45, the predetermined pressure P0, and the above formula (1). And a method for determining the length of the eleventh time zone.

Next, in the 57th time zone, which is the time zone from time t57 to time t58, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 is the predetermined pressure P0 at time t57, the fuel injection device 1 sets the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC at the predetermined pressure in the 57th time zone. The fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC while reducing the pressure from P0 to the pressure P42 corresponding to the length of the 57th time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P42, that is, the length of the 57th time zone, is the predetermined pressure P0, the pressure P42, and the above-described equation (1). Can be calculated based on

Then, since the fuel injection device 1 closes the second valve 22 at time t58, the fuel injection from the second pressure accumulator 122 into the combustion chamber CC stops and is injected from the second pressure accumulator 122 into the combustion chamber CC. The fuel pressure becomes zero in the time zone after time t58. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P42.

With the control method represented by the timing chart shown in FIG. 9, the fuel injection device 1 allows the user to desire a pattern of temporal change in the pressure of the fuel injected into the combustion chamber CC while suppressing an increase in the fuel consumption rate. Among the patterns to be matched with the convex pattern. The convex pattern is the pattern shown in FIG. 9 and the temporal change pattern of the pressure of the fuel injected by the fuel injection device 1 into the combustion chamber CC. That is, in the convex pattern, the pressure of the fuel injected into the combustion chamber CC by the fuel injection device 1 is a period during which the fuel injection device 1 is injecting the fuel (in the example shown in FIG. 9, time t51 to time This is a pattern that increases almost monotonically from the pressure P42 to the predetermined pressure P0 with the passage of time and then monotonously decreases from the predetermined pressure P0 to the pressure P42. In the convex pattern, the fuel injected from the fuel injection device 1 into the combustion chamber CC is higher in the middle period in which the fuel injection device 1 is injecting fuel into the combustion chamber CC than in the previous period and the latter period in the period. Injected by pressure. Thereby, the fuel injection device 1 can atomize the fuel injected into the combustion chamber CC. As a result, the fuel injection device 1 can reduce the amount of noise of the internal combustion engine EG in the drive state, and can further reduce the amount of emissions generated from the internal combustion engine EG.

FIG. 10 is a timing chart for explaining a specific example 6 of the control method of the fuel injection device 1. The control method represented by the timing chart shown in FIG. 10 is a control method for increasing the fuel injection amount in the inverse delta pattern described in FIG. The timing chart shown in FIG. 10 includes four graphs of graphs CH61 to CH64. Each horizontal axis of the graphs CH61 to CH64 represents time. The vertical axis of the graph CH61 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. Further, the vertical axis of the graph CH62 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH63 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. The vertical axis of the graph CH64 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Further, at time t61, time t64, time t66, time t68, and time t70 in the graphs CH61 to CH64, the drive current is supplied from the first valve drive circuit 33 to the drive unit A1, and the first valve 21 is opened. Represents the time. In addition, at time t62, time t65, time t67, time t69, and time t71 in the graphs CH61 to CH64, the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 is stopped. Represents the time when closed. Further, a time t63 in the graph CH61 to the graph CH64 represents a time when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2 and the second valve 22 is opened. Also, time t72 in the graphs CH61 to CH64 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, the time t61 is a time before the time t62, the time t62 is a time before the time t63, the time t63 is a time before the time t64, and the time t64 is a time. It is a time before t65, time t65 is a time before time t66, time t66 is a time before time t67, and time t67 is a time before time t68. The time t68 is a time before the time t69, and the time t69 is a time before the time t70. Moreover, each of the pressure P51, the pressure P52, the pressure P53, the pressure P54, the pressure P55, the pressure P56, the pressure P57, the pressure P58, and the pressure P59 in the graph CH62 and the graph CH64 is a pressure lower than the predetermined pressure P0. The pressure P51 is lower than the pressure P52, the pressure P52 is lower than the pressure P53, the pressure P53 is lower than the pressure P54, and the pressure P54 is lower than the pressure P55. The pressure P55 is lower than the pressure P56, the pressure P56 is lower than the pressure P57, the pressure P57 is lower than the pressure P58, and the pressure P58 is lower than the pressure P59. Is also a low pressure.

In the example shown in FIG. 10, the fuel injection device 1 realizes the first state in the 61st time zone that is the time zone from time t61 to time t62. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P51 in the time zone before time t61. In the 61st time zone, the pressure in the second pressure accumulator 122 is increased according to the elapsed time elapsed from time t61. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In this example, the pressure is increased from the pressure P51 to the predetermined pressure P0 in the 61st time zone. The length of the 61st time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 62nd time zone that is the time zone from time t62 to time t63, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, in the 61st time zone, the pressure in the second pressure accumulating portion 122 is increased from the pressure P51 to the predetermined pressure P0. For these reasons, in the 62nd time zone, the pressure in the second pressure accumulating portion 122 is kept at the predetermined pressure P0.

Next, in the 63rd time zone that is the time zone from time t63 to time t64, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 was maintained at the predetermined pressure P0 in the 62nd time zone, the fuel injection device 1 injected the fuel from the second pressure accumulator 122 into the combustion chamber CC in the 63rd time zone. The fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC while reducing the pressure from a predetermined pressure P0 to a pressure P58 corresponding to the length of the 63rd time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P58, that is, the length of the 63rd time zone, is the predetermined pressure P0, the pressure P58, and the above-described equation (1). Can be calculated based on

Next, in the 64th time zone which is the time zone from time t64 to time t65, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 64th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P58 to the pressure P59 corresponding to the length of the 64th time zone, and then from the second pressure accumulating portion 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P58 at the time t64, and is increased from the pressure P58 to the pressure P59 in the 64th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P58 to the pressure P59, that is, the length of the 64th time zone, is the pressure P58, the pressure P59, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 65th time zone which is the time zone from time t65 to time t66, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 is the pressure P59 at time t65, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC from the pressure P59 in the 65th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to a pressure P56 corresponding to the length of the 65th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P59 to the pressure P56, that is, the length of the 65th time zone is based on the pressure P59, the pressure P56, and the above-described equation (1). Can be calculated.

Next, in the 66th time zone, which is the time zone from time t66 to time t67, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 66th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P56 to the pressure P57 corresponding to the length of the 66th time zone, and then from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P56 at the time t66, and is increased from the pressure P56 to the pressure P57 in the 66th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P56 to the pressure P57, that is, the length of the 66th time zone, is the pressure P56, the pressure P57, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 67th time zone which is the time zone from time t67 to time t68, the fuel injection device 1 realizes the second state by performing the pressure reduction control. Since the pressure in the second pressure accumulator 122 is the pressure P57 at time t67, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC from the pressure P57 in the 67th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P54 corresponding to the length of the 67th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P57 to the pressure P54, that is, the length of the 67th time zone is based on the pressure P57, the pressure P54, and the above-described equation (1). Can be calculated.

Next, in the 68th time zone which is the time zone from time t68 to time t69, the fuel injection device 1 realizes the third state by performing the pressure increase control. In the 68th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P54 to the pressure P55 corresponding to the length of the 68th time zone, and then from the second pressure accumulating portion 122 to the combustion chamber CC. Fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P54 at time t68, and is increased from the pressure P54 to the pressure P55 in the 68th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P54 to the pressure P55, that is, the length of the 68th time zone, is the pressure P54, the pressure P55, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in a 69th time zone that is a time zone from time t69 to time t70, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 is the pressure P55 at time t69, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC from the pressure P55 in the 69th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P52 corresponding to the length of the 69th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P55 to the pressure P52, that is, the length of the 69th time zone is based on the pressure P55, the pressure P52, and the above-described equation (1). Can be calculated.

Next, in the 70th time zone which is the time zone from time t70 to time t71, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 70th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P52 to the pressure P53 corresponding to the length of the 70th time zone, and then from the second pressure accumulating portion 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P52 at the time t70, and is increased from the pressure P52 to the pressure P53 in the 70th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P52 to the pressure P53, that is, the length of the 70th time zone is the pressure P52, the pressure P53, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 71st time slot | zone which is a time slot | zone of the time t71-the time t72, the fuel injection apparatus 1 has implement | achieved the 2nd state by performing pressure reduction control. Since the pressure in the second accumulator 122 is the pressure P53 at time t71, the fuel injection device 1 changes the pressure of the fuel injected from the second accumulator 122 into the combustion chamber CC from the pressure P53 in the 71st time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P51 corresponding to the length of the 71st time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P53 to the pressure P51, that is, the length of the 71st time zone is based on the pressure P53, the pressure P51, and the above-described equation (1). Can be calculated.

Then, since the fuel injection device 1 closes the second valve 22 at time t72, the fuel injection from the second pressure accumulating portion 122 into the combustion chamber CC stops and is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t72. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P51.

By the control method represented by the timing chart shown in FIG. 10, the fuel injection device 1 injects into the combustion chamber CC while suppressing an increase in the fuel consumption rate, similarly to the control method represented by the timing chart shown in FIG. The pattern of the temporal change in the fuel pressure can be matched with the inverse delta pattern among the patterns desired by the user. Further, according to the control method represented by the timing chart shown in FIG. 10, the fuel injection device 1 causes the combustion chamber CC to generate more fuel than the fuel injected into the combustion chamber CC by the control method represented by the timing chart shown in FIG. Can be injected inside. As a result, the fuel injection device 1 causes the fuel flame to collide with the inner wall of the combustion chamber CC by the collision of the fuel with the inner wall of the fuel chamber CC due to excessive fuel spray or the collision of the fuel with the inner wall of the fuel chamber CC due to the flame after ignition. Cooling loss caused by being cooled can be suppressed.

FIG. 11 is a timing chart for explaining a specific example 7 of the control method of the fuel injection device 1. The timing chart shown in FIG. 11 includes four graphs of graphs CH71 to CH74. Each horizontal axis of the graphs CH71 to CH74 represents time. In addition, the vertical axis of the graph CH71 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. Further, the vertical axis of the graph CH72 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH73 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. Further, the vertical axis of the graph CH74 represents the pressure of fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Further, each of time t81, time t84, time t86, and time t88 in the graphs CH71 to CH74 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. . In addition, at time t82, time t85, time t87, and time t89 in the graphs CH71 to CH74, the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 is closed. Represents the time. Further, a time t83 in the graphs CH71 to CH74 represents a time at which the second valve 22 is opened when a drive current is supplied from the second valve drive circuit 34 to the drive unit A2. Also, time t90 in the graphs CH71 to CH74 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t81 is a time before time t82, time t82 is a time before time t83, time t83 is a time before time t84, and time t84 is a time. It is a time before t85, time t85 is a time before time t86, time t86 is a time before time t87, and time t87 is a time before time t88. , Time t88 is a time before time t89, and time t89 is a time before time t90. Further, each of the pressure P61 and the pressure P62 in the graph CH72 and the graph CH74 is a pressure lower than the predetermined pressure P0. Further, the pressure P61 is a pressure lower than the pressure P62.

In the example shown in FIG. 11, the fuel injection device 1 realizes the first state in the 81st time zone that is the time zone from time t81 to time t82. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P61 in the time zone before time t81. In the 81st time zone, the pressure in the second pressure accumulator 122 is increased according to the elapsed time elapsed from time t81. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In this example, the pressure is increased from the pressure P61 to the predetermined pressure P0 in the 81st time zone. The length of the 81st time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 82nd time zone which is the time zone from time t82 to time t83, the fuel injection device 1 closes both the first valve 21 and the second valve 22. In the 81st time zone, the pressure in the second pressure accumulating portion 122 is increased from the pressure P61 to the predetermined pressure P0. For these reasons, the pressure in the second pressure accumulator 122 is maintained at the predetermined pressure P0 in the 82nd time zone.

Next, in the 83rd time zone that is the time zone from time t83 to time t84, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is maintained at the predetermined pressure P0 in the 82nd time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC in the 83rd time zone. The fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC while reducing the pressure from the predetermined pressure P0 to the pressure P61 corresponding to the length of the 83rd time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P61, that is, the length of the 83rd time zone, is the predetermined pressure P0, the pressure P61, and the above-described equation (1). Can be calculated based on

Next, in the 84th time zone which is the time zone from time t84 to time t85, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 84th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P61 to the pressure P62 corresponding to the length of the 84th time zone, and then from the second pressure accumulating portion 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P61 at the time t84, and is increased from the pressure P61 to the pressure P62 in the 84th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P61 to the pressure P62, that is, the length of the 84th time zone, is the pressure P61, the pressure P62, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 85th time zone which is the time zone from time t85 to time t86, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is the pressure P62 at time t85, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC from the pressure P62 in the 85th time zone. The fuel is injected from the second accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P61 corresponding to the length of the 85th time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the pressure P62 to the pressure P61, that is, the length of the 85th time zone is based on the pressure P62, the pressure P61, and the above-described equation (1). Can be calculated.

Next, in the 86th time zone which is the time zone from time t86 to time t87, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 86th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P61 to the pressure P62 corresponding to the length of the 86th time zone, from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P61 at the time t86, and is increased from the pressure P61 to the pressure P62 in the 86th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P61 to the pressure P62, that is, the length of the 86th time zone, is the pressure P61, the pressure P62, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 87th time zone which is a time zone from time t87 to time t88, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is the pressure P62 at time t87, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC from the pressure P62 in the 87th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P61 corresponding to the length of the 87th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P62 to the pressure P61, that is, the length of the 87th time zone is based on the pressure P62, the pressure P61, and the above-described equation (1). Can be calculated.

Next, in the 88th time zone which is the time zone from time t88 to time t89, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 88th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P61 to the pressure P62 corresponding to the length of the 88th time zone, and then from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P61 at the time t88, and is increased from the pressure P61 to the pressure P62 in the 88th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P61 to the pressure P62, that is, the length of the 86th time zone, is the pressure P61, the pressure P62, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 89th time zone which is the time zone from time t89 to time t90, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is the pressure P62 at time t89, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC from the pressure P62 in the 89th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to a pressure P61 corresponding to the length of the 89th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P62 to the pressure P61, that is, the length of the 89th time zone, is based on the pressure P62, the pressure P61, and the above-described equation (1). Can be calculated.

Then, since the fuel injection device 1 closes the second valve 22 at time t90, the fuel injection from the second pressure accumulating portion 122 into the combustion chamber CC stops and is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t90. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P61.

With the control method represented by the timing chart shown in FIG. 11, the fuel injection device 1 allows the user to select a temporal change pattern of the pressure of the fuel injected into the combustion chamber CC while suppressing an increase in the fuel consumption rate. Of the patterns to be matched with the L-shaped pattern. The L-shaped pattern is the pattern shown in FIG. 11 and is a pattern of temporal change in the pressure of fuel injected by the fuel injection device 1 into the combustion chamber CC. That is, in the L-shaped pattern, the pressure of the fuel injected into the combustion chamber CC by the fuel injection device 1 is a period during which the fuel injection device 1 is injecting fuel (in the example shown in FIG. 11, time t83 to time This is a pattern that monotonously decreases from the predetermined pressure P0 to the pressure P61 with the passage of time in the time period t90), and then remains substantially at the pressure P61. In the L-type pattern, the fuel injected from the fuel injection device 1 into the combustion chamber CC is injected more uniformly into the combustion chamber CC during the period compared to the case of the inverse delta pattern. As a result, the fuel injection device 1 causes the fuel flame to collide with the inner wall of the combustion chamber CC due to the collision of the fuel with the inner wall of the fuel chamber CC due to excessive fuel spray or the collision of the fuel with the inner wall of the fuel chamber CC due to the flame after ignition. The cooling loss caused by being cooled can be further suppressed.

FIG. 12 is a timing chart for explaining a specific example 8 of the control method of the fuel injection device 1. The timing chart shown in FIG. 12 includes four graphs of graphs CH81 to CH84. Each horizontal axis of graph CH81-graph CH84 represents time. The vertical axis of the graph CH81 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. The vertical axis of the graph CH82 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH83 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. The vertical axis of the graph CH84 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. In addition, each of time t91, time t94, time t96, and time t98 in the graphs CH81 to CH84 represents a time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. . In addition, at time t92, time t95, time t97, and time t99 in the graphs CH81 to CH84, the supply of drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 is closed. Represents the time. In addition, time t93 in the graphs CH81 to CH84 represents the time when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2 and the second valve 22 is opened. In addition, time t100 in the graphs CH81 to CH84 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t91 is a time before time t92, time t92 is a time before time t93, time t93 is a time before time t94, and time t94 is a time. Time before t95, time t95 is a time before time t96, time t96 is a time before time t97, and time t97 is a time before time t98. The time t98 is a time before the time t99, and the time t99 is a time before the time t100. Moreover, each of the pressure P71, the pressure P72, and the pressure P73 in the graph CH82 and the graph CH84 is a pressure lower than the predetermined pressure P0. Moreover, the pressure P71 is a pressure lower than the pressure P72, and the pressure P72 is a pressure lower than the pressure P73.

In the example shown in FIG. 12, the fuel injection device 1 realizes the first state in the 91st time zone that is the time zone from time t91 to time t92. Here, in this example, a case where the pressure in the second pressure accumulating unit 122 is the pressure P71 in the time zone before time t91 will be described. In the 91st time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t91. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In the example, in the 91st time zone, the pressure is increased from the pressure P71 to the pressure P73 corresponding to the length of the 91st time zone. The length of the 91st time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 92nd time zone that is the time zone from time t92 to time t93, the fuel injection device 1 closes both the first valve 21 and the second valve 22. In the 91st time zone, the pressure in the second pressure accumulating unit 122 is increased from the pressure P71 to the pressure P73. For these reasons, the pressure in the second pressure accumulator 122 is maintained at the pressure P73 in the 92nd time zone.

Next, in the 93rd time zone, which is the time zone from time t93 to time t94, the fuel injection device 1 realizes the second state by performing pressure reduction control. In the 92nd time zone, the pressure in the second pressure accumulator 122 was kept at the pressure P73, so in the 93rd time zone, the fuel injection device 1 supplies the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. The fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC while reducing the pressure from the pressure P73 to the pressure P71 corresponding to the length of the 93rd time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P73 to the pressure P71, that is, the length of the 93rd time zone is based on the pressure P73, the pressure P71, and the above-described equation (1). Can be calculated.

Next, in the 94th time zone which is the time zone from time t94 to time t95, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 94th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P71 to the pressure P72 corresponding to the length of the 94th time zone, and then from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P71 at time t94, and is increased from the pressure P71 to the pressure P72 in the 94th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P71 to the pressure P72, that is, the length of the 94th time zone, is the pressure P71, the pressure P72, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 95th time zone that is the time zone from time t95 to time t96, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second accumulator 122 is the pressure P72 at time t95, the fuel injection device 1 changes the pressure of the fuel injected from the second accumulator 122 into the combustion chamber CC from the pressure P72 in the 95th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P71 corresponding to the length of the 95th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P72 to the pressure P71, that is, the length of the 95th time zone is based on the pressure P72, the pressure P71, and the above-described equation (1). Can be calculated.

Next, in the 96th time zone that is the time zone from time t96 to time t97, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 96th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulating portion 122 from the pressure P71 to the pressure P72 corresponding to the length of the 96th time zone, and then from the second pressure accumulating portion 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P71 at the time t96, and is increased from the pressure P71 to the pressure P72 in the 96th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P71 to the pressure P72, that is, the length of the 96th time zone, is the pressure P71, the pressure P72, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 97th time zone which is the time zone from time t97 to time t98, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is the pressure P72 at time t97, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC from the pressure P72 in the 97th time zone. The fuel is injected from the second accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P71 corresponding to the length of the 97th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P72 to the pressure P71, that is, the length of the 97th time zone is based on the pressure P72, the pressure P71, and the above-described equation (1). Can be calculated.

Next, in the 98th time zone which is the time zone from time t98 to time t99, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 98th time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC while increasing the pressure in the second pressure accumulator 122 from the pressure P71 to the predetermined pressure P0. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P71 at time t98, and is increased from the pressure P71 to the predetermined pressure P0 in the 98th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P71 to the predetermined pressure P0, that is, the length of the 96th time zone, is the pressure P71, the predetermined pressure P0, and the above formula (1). And a method for determining the length of the eleventh time zone.

Next, in the 99th time zone which is the time zone from time t99 to time t100, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 is the predetermined pressure P0 at time t99, in the 99th time zone, the fuel injection device 1 sets the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC to the predetermined pressure. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure from P0 to a pressure P71 corresponding to the length of the 99th time zone. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P71, that is, the length of the 99th time zone, is the predetermined pressure P0, the pressure P71, and the above-described equation (1). Can be calculated based on

Then, since the fuel injection device 1 closes the second valve 22 at time t100, the fuel injection from the second pressure accumulating portion 122 into the combustion chamber CC stops and is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t100. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P71.

With the control method represented by the timing chart shown in FIG. 12, the fuel injection device 1 allows the user to select a pattern of temporal change in the pressure of the fuel injected into the combustion chamber CC while suppressing an increase in the fuel consumption rate. Among the patterns to be matched with the inverted L-shaped pattern. The inverted L-shaped pattern is the pattern shown in FIG. 12 and the pattern of temporal change in the pressure of the fuel injected by the fuel injection device 1 into the combustion chamber CC. That is, the reverse L-shaped pattern indicates that the pressure of the fuel injected into the combustion chamber CC by the fuel injection device 1 is a period during which the fuel injection device 1 is injecting fuel (in the example shown in FIG. This is a pattern in which the pressure P72 is kept almost constant with the passage of time at time t100), and then monotonously increases to a predetermined pressure and then monotonously decreases to pressure P71 again. In the reverse L type pattern, the fuel injected from the fuel injection device 1 into the combustion chamber CC is injected at a higher pressure in the latter period in the period than in the first period in the period, as in the delta pattern. However, in the inverted L-type pattern, the fuel injection device 1 can further atomize the fuel injected into the combustion chamber CC as compared with the delta-type pattern, and disturb the combustion of the fuel in the combustion chamber CC. Can be caused further. As a result, the fuel injection device 1 can further reduce the amount of noise of the internal combustion engine EG in the driven state, and further reduce the amount of emissions generated from the internal combustion engine EG, as compared with the delta pattern. Can do.

FIG. 13 is a timing chart for explaining a specific example 9 of the control method of the fuel injection device 1. The timing chart shown in FIG. 13 includes four graphs of graphs CH91 to CH94. Each horizontal axis of the graphs CH91 to CH94 represents time. In addition, the vertical axis of the graph CH91 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. In addition, the vertical axis of the graph CH92 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH93 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. The vertical axis of the graph CH94 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Further, at time t101, time t104, time t106, time t108, and time t110 in the graphs CH91 to CH94, the drive current is supplied from the first valve drive circuit 33 to the drive unit A1, and the first valve 21 is opened. Represents the time. In addition, at time t102, time t105, time t107, time t109, and time t111 in the graphs CH91 to CH94, the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 Represents the time when closed. Further, a time t103 in the graphs CH91 to CH94 represents a time when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2 and the second valve 22 is opened. Also, time t112 in the graphs CH91 to CH94 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, the time t101 is a time before the time t102, the time t102 is a time before the time t103, the time t103 is a time before the time t104, and the time t104 is a time It is a time before t105, time t105 is a time before time t106, time t106 is a time before time t107, and time t107 is a time before time t108 The time t108 is a time before the time t109, the time t109 is a time before the time t110, the time t110 is a time before the time t111, and the time t111 is from the time t112. Is the previous time. In addition, each of the pressure P81, the pressure P82, and the pressure P83 in the graph CH92 and the graph CH94 is lower than the predetermined pressure P0. Moreover, the pressure P81 is a pressure lower than the pressure P82, and the pressure P82 is a pressure lower than the pressure P83.

In the example shown in FIG. 13, the fuel injection device 1 realizes the first state in the 101st time zone that is the time zone from the time t101 to the time t102. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P81 in the time zone before the time t101. In the 101st time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t101. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In the example, in the 101st time zone, the pressure is increased from the pressure P81 to the pressure P83 corresponding to the length of the 101st time zone. The length of the 101st time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 102nd time zone which is the time zone from time t102 to time t103, the fuel injection device 1 closes both the first valve 21 and the second valve 22. In the 101st time zone, the pressure in the second pressure accumulator 122 is increased from the pressure P81 to the pressure P83. For these reasons, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P83 in the 102nd time zone.

Next, in the 103rd time zone, which is the time zone from time t103 to time t104, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 was maintained at the pressure P83 in the 102nd time zone, the fuel injection device 1 in the 103th time zone has the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel is injected from the second pressure accumulating section 122 into the combustion chamber CC while reducing the pressure from the pressure P83 to the pressure P82 corresponding to the length of the 103rd time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P83 to the pressure P82, that is, the length of the 103rd time zone is based on the pressure P83, the pressure P82, and the above-described equation (1). Can be calculated.

Next, in the 104th time zone which is the time zone from time t104 to time t105, the fuel injection device 1 realizes the third state by performing the pressure increase control. In the 104th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P82 to the pressure P83 corresponding to the length of the 104th time zone, from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P82 at time t104, and is increased from the pressure P82 to the pressure P83 in the 104th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P82 to the pressure P83, that is, the length of the 104th time zone, is the pressure P82, the pressure P83, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 105th time zone that is the time zone from time t105 to time t106, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second accumulator 122 is the pressure P83 at time t105, the fuel injection device 1 changes the pressure of the fuel injected from the second accumulator 122 into the combustion chamber CC from the pressure P83 in the 105th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P82 corresponding to the length of the 105th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P83 to the pressure P82, that is, the length of the 105th time zone is based on the pressure P83, the pressure P82, and the above-described equation (1). Can be calculated.

Next, in the 106th time zone that is the time zone from time t106 to time t107, the fuel injection device 1 realizes the third state by performing the pressure increase control. In the 106th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P82 to the pressure P83 corresponding to the length of the 106th time zone, and then from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P82 at time t106, and is increased from the pressure P82 to the pressure P83 in the 106th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P82 to the pressure P83, that is, the length of the 106th time zone is the pressure P82, the pressure P83, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 107th time zone, which is the time zone from time t107 to time t108, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is the pressure P83 at time t107, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC from the pressure P83 in the 107th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P82 corresponding to the length of the 107th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P83 to the pressure P82, that is, the length of the 107th time zone is based on the pressure P83, the pressure P82, and the above-described equation (1). Can be calculated.

Next, in the 108th time zone, which is the time zone from time t108 to time t109, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 108th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P82 to the pressure P83 corresponding to the length of the 108th time zone, and then from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. Thus, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P82 at the time t108, and is increased from the pressure P82 to the pressure P83 in the 108th time zone. The time required for the pressure in the second pressure accumulating section 122 to be increased from the pressure P82 to the pressure P83, that is, the length of the 108th time zone, is the pressure P82, the pressure P83, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 109th time zone, which is the time zone from time t109 to time t110, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 is the pressure P83 at time t109, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC from the pressure P83 in the 109th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P82 corresponding to the length of the 109th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P83 to the pressure P82, that is, the length of the 109th time zone is based on the pressure P83, the pressure P82, and the above-described equation (1). Can be calculated.

Next, in the 110th time zone that is the time zone from time t110 to time t111, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 110th time zone, the fuel injection device 1 increases the pressure in the second pressure accumulator 122 from the pressure P82 to the pressure P83 corresponding to the length of the 110th time zone, and then from the second pressure accumulator 122 to the combustion chamber CC. The fuel is injected into the inside. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC is the pressure P82 at time t110, and is increased from the pressure P82 to the pressure P83 in the 110th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P82 to the pressure P83, that is, the length of the 110th time zone, is the pressure P82, the pressure P83, the above-described equation (1), It can be calculated based on the method for determining the length of the eleventh time zone.

Next, in the 111th time zone that is the time zone from time t111 to time t112, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulating portion 122 is the pressure P83 at time t111, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC from the pressure P83 in the 111th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to the pressure P81 corresponding to the length of the 111th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P83 to the pressure P81, that is, the length of the 111th time zone is based on the pressure P83, the pressure P81, and the above-described equation (1). Can be calculated.

Then, since the fuel injection device 1 closes the second valve 22 at time t112, the fuel injection from the second pressure accumulator 122 into the combustion chamber CC stops and is injected from the second pressure accumulator 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t112. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P81.

With the control method represented by the timing chart shown in FIG. 13, the fuel injection device 1 suppresses an increase in the fuel consumption rate, and the pressure of the fuel injected into the combustion chamber CC is a pressure lower than the predetermined pressure P0. The fuel can be injected into the combustion chamber CC while maintaining the pressure P83 substantially. That is, the fuel injection device 1 can inject fuel into the combustion chamber CC at a pressure equal to or lower than the pressure supplied from the high pressure source 4 and desired by the user.

FIG. 14 is a timing chart for explaining a specific example 10 of the control method of the fuel injection device 1. Specific example 10 of the control method is a combination of a part or all of the control methods described above, so that multiple injections, for example, pilot injection, pre-injection, main injection, and after-injection are sequentially performed on the fuel injection device 1. This is a control method to be performed. The timing chart shown in FIG. 14 includes four graphs of graphs CH101 to CH104. Each horizontal axis of the graphs CH101 to CH104 represents time. In addition, the vertical axis of the graph CH101 represents the drive current supplied from the first valve drive circuit 33 to the drive unit A1. Further, the vertical axis of the graph CH102 represents the pressure in the second pressure accumulating unit 122. In addition, the vertical axis of the graph CH103 represents the drive current supplied from the second valve drive circuit 34 to the drive unit A2. The vertical axis of the graph CH104 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Each of time t125 and time t129 in the graphs CH101 to CH104 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. Each of time t127 and time t130 in the graphs CH101 to CH104 represents the time when the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped and the first valve 21 is closed. In addition, each of time t121, time t123, time t126, and time t130 in the graphs CH101 to CH104 represents the time when the second valve drive circuit 34 supplies the drive current to the drive unit A2 and the second valve 22 is opened. . In addition, at time t122, time t124, time t128, and time t131 in the graphs CH101 to CH104, the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped, and the second valve 22 is closed. Represents the time. Here, time t121 is a time before time t122, time t122 is a time before time t123, time t123 is a time before time t124, and time t124 is a time Time before t125, time t125 is a time before time t126, time t126 is a time before time t127, and time t127 is a time before time t128. The time t128 is a time before the time t129, the time t129 is a time before the time t130, and the time t130 is a time before the time t131. Moreover, each of the pressure P91, the pressure P92, the pressure P93, the pressure P94, the pressure P95, and the pressure P96 in the graph CH102 and the graph CH104 is a pressure lower than the predetermined pressure P0. The pressure P91 is lower than the pressure P92, the pressure P92 is lower than the pressure P93, the pressure P93 is lower than the pressure P94, and the pressure P94 is lower than the pressure P95. This is a pressure, and the pressure P95 is lower than the pressure P96.

In the example shown in FIG. 14, in the 121st time zone that is the time zone from time t121 to time t122, the fuel injection device 1 realizes the second state by performing pressure reduction control, and performs pilot injection. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P94 in the time zone before time t121. Since the pressure in the second pressure accumulating portion 122 was maintained at the pressure P94 in the 121st time zone, in the 121st time zone, the fuel injection device 1 supplies the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel is injected from the second pressure accumulating section 122 into the combustion chamber CC while reducing the pressure from the pressure P94 to the pressure P93 corresponding to the length of the 121st time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P94 to the pressure P93, that is, the length of the 121st time zone is based on the pressure P94, the pressure P93, and the above-described equation (1). Can be calculated.

Next, in the 122nd time zone which is the time zone from time t122 to time t123, the fuel injection device 1 closes both the first valve 21 and the second valve 22. In the 121st time zone, the pressure in the second pressure accumulator 122 is reduced from the pressure P94 to the pressure P93. For these reasons, the pressure in the second pressure accumulator 122 is maintained at the pressure P93 in the 122nd time zone.

Next, in the 123rd time zone that is the time zone from time t123 to time t124, the fuel injection device 1 realizes the second state by performing pressure reduction control, and performs pre-injection. In the 122th time zone, the pressure in the second pressure accumulating portion 122 was maintained at the pressure P93, so in the 123rd time zone, the fuel injection device 1 supplies the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC while reducing the pressure from the pressure P93 to the pressure P92 corresponding to the length of the 123rd time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P93 to the pressure P92, that is, the length of the 123rd time zone is based on the pressure P93, the pressure P92, and the above-described equation (1). Can be calculated.

Next, in the 124th time zone that is the time zone from time t124 to time t125, the fuel injection device 1 closes both the first valve 21 and the second valve 22. In the 123rd time zone, the pressure in the second pressure accumulating portion 122 is reduced from the pressure P93 to the pressure P92. For these reasons, the pressure in the second pressure accumulating section 122 is maintained at the pressure P92 in the 124th time zone.

Next, in the 125th time zone which is the time zone from time t125 to time t126, the fuel injection device 1 realizes the first state. In the 125th time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t125. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In the example, the pressure is increased from the pressure P92 to the pressure P96 in the 125th time zone. The length of the 125th time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 126th time zone which is the time zone from time t126 to time t127, the fuel injection device 1 realizes the third state by performing pressure increase control. In the 126th time zone, the fuel injection device 1 injects fuel from the second pressure accumulator 122 into the combustion chamber CC while increasing the pressure in the second pressure accumulator 122 from the pressure P96 to the predetermined pressure P0. As a result, the pressure of the fuel injected from the second pressure accumulating portion 122 into the combustion chamber CC is the pressure P96 at time t126, and is increased from the pressure P96 to the predetermined pressure P0 in the 126th time zone. The time required for the pressure in the second pressure accumulator 122 to be increased from the pressure P96 to the predetermined pressure P0, that is, the length of the 126th time zone, is the pressure P96, the predetermined pressure P0, and the above-described equation (1). And a method for determining the length of the eleventh time zone.

Next, in the 127th time zone which is a time zone from time t127 to time t128, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second pressure accumulator 122 is the predetermined pressure P0 at time t127, the fuel injection device 1 supplies the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC at the predetermined pressure in the 127th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure from P0 to a pressure P91 corresponding to the length of the 127th time zone. The time required for the pressure in the second pressure accumulating section 122 to be reduced from the predetermined pressure P0 to the pressure P91, that is, the length of the 127th time zone is the predetermined pressure P0, the pressure P91, and the above-described equation (1). Can be calculated based on

Next, in the 128th time zone which is the time zone from time t128 to time t129, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulating portion 122 is reduced from the predetermined pressure P0 to the pressure P91 in the 128th time zone. For these reasons, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P91 in the 128th time zone.

The fuel injection device 1 performs main injection during a period from time t125 to time t129.

Next, in the 129th time zone that is the time zone from time t129 to time t130, the fuel injection device 1 realizes the first state. In the 129th time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t129. Further, since the pressure of the fuel supplied to the second pressure accumulating portion 122 is the predetermined pressure P0, the pressure in the second pressure accumulating portion 122 can be increased up to the predetermined pressure P0. In the example, the pressure is increased from the pressure P91 to the pressure P95 in the 129th time zone. The length of the 129th time zone is determined by the user, similar to the length of the 11th time zone.

Next, in the 130th time zone that is the time zone from time t130 to time t131, the fuel injection device 1 realizes the second state by performing pressure reduction control, and performs after-injection. Since the pressure in the second pressure accumulator 122 is the pressure P95 at time t130, the fuel injection device 1 changes the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC from the pressure P95 in the 130th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure to a pressure P94 corresponding to the length of the 130th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P95 to the pressure P94, that is, the length of the 130th time zone is based on the pressure P95, the pressure P94, and the above-described equation (1). Can be calculated.

Then, since the fuel injection device 1 closes the second valve 22 at time t131, fuel injection from the second pressure accumulator 122 into the combustion chamber CC stops and is injected from the second pressure accumulator 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t131. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P94.

With the control method represented by the timing chart shown in FIG. 14, the fuel injection device 1 can perform each of the pilot injection, the pre-injection, the main injection, and the after injection described above while suppressing an increase in the fuel consumption rate. it can. In the example shown in FIG. 14, the fuel injection device 1 injects fuel into the combustion chamber CC at a pressure lower than the pressure of the fuel injected into the combustion chamber CC in the main injection in the pilot injection and the pre-injection. ing. Thereby, the fuel injection device 1 can reduce the amount of noise of the internal combustion engine EG, and can further reduce the amount of emission of the internal combustion engine EG. In this example, the fuel injection device 1 injects fuel into the combustion chamber CC using the above-described inverse delta pattern. Further, the fuel injection device 1 has a pressure lower than the pressure of fuel injected into the combustion chamber CC in the main injection in the after injection and higher than the pressure of fuel injected into the combustion chamber CC in the pilot injection. Fuel is injected into the combustion chamber CC by pressure. As a result, the fuel injection device 1 can cause turbulent combustion in the combustion chamber CC in the 130th time zone, and reduce the amount of emissions generated by the internal combustion engine EG.

Next, with reference to FIGS. 15 to 18, the case where a dynamic effect associated with the movement of fuel in the fuel injection device 1 acts will be described.
FIG. 15 is a timing chart for explaining a specific example 11 of the control method of the fuel injection device 1. Specific example 11 of the control method is a control method for causing the fuel injection device 1 to perform multi-stage injection, for example, pilot injection, pre-injection, and main injection, by combining some or all of the control methods described above. It is. Note that the above control method does not limit the implementation of after-injection, and may be implemented as appropriate. The timing chart shown in FIG. 15 includes four graphs of graph CH111 to graph CH114. Each horizontal axis of the graphs CH111 to CH114 represents time. Further, the vertical axis of the graph CH111 represents the state of the valve A1V by binary values of an open state and a closed state. Hereinafter, it simply refers to the state of the valve A1V. Note that the timing at which the state of the valve A1V changes is slightly delayed from the timing at which the drive current supplied from the first valve drive circuit 33 to the drive unit A1 is changed. In addition, the vertical axis of the graph CH112 represents the pressure in the second pressure accumulating unit 122. Further, the vertical axis of the graph CH113 represents the state of the valve A2V by binary values of an open state and a closed state. Hereinafter, it simply refers to the state of the valve A2V. The timing at which the state of the valve A2V changes is slightly delayed from the timing at which the drive current supplied from the second valve drive circuit 34 to the drive unit A2 is changed. The vertical axis of the graph CH114 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. In addition, each of time t141, time t150, time t154, and time t158 in the graphs CH111 to CH114 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. . Further, at time t142, time t152, time t156, and time t160 in the graphs CH111 to CH114, the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 is closed. Represents the time. Further, each of time t151, time t155, and time t159 in the graphs CH111 to CH114 represents the time when the second valve 22 is opened when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2. Each of time t153, time t157, and time t161 in the graphs CH111 to CH114 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. . Note that at time t143, time t145, and time t147 in the graphs CH111 to CH114, a drive current is supplied from the second valve drive circuit 34 to the drive unit A2, and the valve A2V discharges fuel from the second pressure accumulating unit 122. Represents the time at which. In addition, at time t144, time t146, and time t148 in the graphs CH111 to CH114, the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped, and the valve A2V is supplied from the second pressure accumulating unit 122. Indicates the time when fuel discharge was stopped. Here, time t141 is a time before time t142, time t142 is a time before time t143, time t143 is a time before time t144, and time t144 is a time. It is a time before t145, time t145 is a time before time t146, time t146 is a time before time t147, and time t147 is a time before time t148. , Time t148 is a time before time t150, time t150 is a time before time t152, time t152 is a time before time t151, and time t151 is from time t153 The time t153 is a time before the time t154, the time t154 is a time before the time t156, and the time t1 6 is a time before time t155, time t155 is a time before time t157, time t157 is a time before time t158, and time t158 is before time t159. The time t159 is a time before the time t160, and the time t160 is a time before the time t161. Moreover, each of the pressure P101, the pressure P103, the pressure P104, and the pressure P105 in the graph CH112 and the graph CH114 is a pressure that is higher than 0 and lower than the predetermined pressure P0, and the pressure P107 is a pressure higher than the predetermined pressure P0. The pressure P101 is lower than the pressure P103, the pressure P103 is lower than the pressure P104, and the pressure P104 is lower than the pressure P105.

In the example shown in FIG. 15, the fuel injection device 1 realizes the first state in the 141st time zone that is the time zone from time t141 to time t142. Here, in this example, a case will be described in which the pressure in the second pressure accumulating unit 122 is the pressure P101 in the time zone before the time t141. In the 141st time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t141. For example, the pressure in the second pressure accumulating unit 122 is increased from the pressure P103 to the pressure P107 by the pressure increasing effect accompanying the movement of the fuel. The pressure increase effect accompanying the movement of the fuel is, for example, the inertial force of the fuel due to the movement of the fuel existing in the fuel supply pipe 121 between the high pressure source 4 and the second pressure accumulator 122. This means that a pressure higher than the predetermined pressure P0 is generated. By using the dynamic effect due to the inertial force of the fuel, the pressure in the second pressure accumulating unit 122 can be increased to a pressure exceeding the predetermined pressure P0 without using an active pressure increasing mechanism (pressurizer). The length of the 141st time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 142nd time zone that is the time zone from time t142 to time t143, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulating portion 122 is increased from the pressure P101 to the pressure P107 in the 141st time zone. For these reasons, the pressure in the second pressure accumulator 122 is maintained at the pressure P107 in the 142nd time zone.

Next, in the 143rd time zone, which is the time zone from time t143 to time t144, the fuel injection device 1 realizes the fourth state by performing non-injection pressure reduction control. The fourth state is a state in which the first valve 21 is closed and the valve A2V is subjected to non-injection decompression control while the second valve 22 is kept closed. The non-injection decompression control is an example of a technique for reducing the pressure in the second pressure accumulator 122 without injecting fuel from the second pressure accumulator 122 into the combustion chamber CC. The valve A2V is realized by letting a drive current flow for a short time so that the valve A2V opens for a minute time that the actuator does not respond. Since the pressure in the second pressure accumulating portion 122 was maintained at the pressure P107 in the previous 142 time zone, the fuel injection device 1 changed the fuel pressure in the second pressure accumulating portion 122 from the pressure P107 in the 143 time zone. The pressure is reduced to the pressure P105 according to the length of the 143rd time zone. The pressure P105 depends on the length of the 143rd time zone. The length of the 143rd time zone is longer than the time from when the drive current starts to flow to the valve A2V until the valve A2V responds and starts discharging fuel, and the second valve 22 responds and starts fuel injection. It is determined in advance to be shorter than the time until. That is, the second valve drive circuit 34 causes a predetermined drive current to flow through the valve A2V during the 143rd time period, whereby the pressure in the second pressure accumulator 122 is reduced from the pressure P107 to the pressure P105.

Next, in the 144th time zone that is the time zone from time t144 to time t145, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulator 122 is reduced to the pressure P105 in the 143rd time zone. For these reasons, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P105 in the 144th time zone.

Next, in the 145th time zone, which is the time zone from time t145 to time t146, the fuel injection device 1 realizes the fourth state by performing non-injection decompression control.
Since the pressure in the second pressure accumulating portion 122 was maintained at the pressure P105 in the 144th time zone, the fuel injection device 1 changed the fuel pressure in the second pressure accumulating portion 122 from the pressure P105 to the pressure P104 in the 145th time zone. Reduce pressure.

Next, in the 146th time zone that is the time zone from time t146 to time t147, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulator 122 is reduced to the pressure P105 in the 145th time zone. For these reasons, in the 146th time zone, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P104.

Next, in the 147th time zone, which is the time zone from time t147 to time t148, the fuel injection device 1 realizes the fourth state by performing non-injection decompression control. Since the pressure in the second pressure accumulating portion 122 was maintained at the pressure P104 in the previous 146 time zone, the fuel injection device 1 changed the fuel pressure in the second pressure accumulating portion 122 from the pressure P104 in the 145 time zone. Depressurize to P103. The pressure P103 is a pressure reduction target pressure. Here, it is assumed that the fuel pressure in the second pressure accumulator 122 has reached the pressure reduction target pressure P103 by the current non-injection pressure reduction control. The number of times to repeat the fourth state is not limited to the above, and may be appropriately determined based on the magnitude that can be reduced by one non-injection pressure reduction control, the pressure P107, and the pressure P103 that is the target for pressure reduction. Alternatively, the pressure in the second pressure accumulating unit 122 reached by performing the non-injection pressure reduction control a predetermined number of times may be regarded as the pressure reduction target pressure (pressure P103).

Next, in the 148th time zone that is the time zone from time t148 to time t150, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulator 122 is reduced to the pressure P103 in the 147th time zone. For these reasons, in the 148th time zone, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P103.

Next, in the time period from time t150 to time t153, the fuel injection device 1 performs so-called pilot injection. For example, in the 150th time zone that is the time zone from time t150 to time t152, the fuel injection device 1 realizes the first state described above. In the 150th time zone, the pressure in the second pressure accumulating portion 122 is increased according to the elapsed time from the time t150 and becomes the pressure P104. The period of the 150th time zone is so small as to compensate for the pressure reduction in the second pressure accumulating unit 122 by controlling the valve A2V, and the pressure increase with respect to the pressure P103 is small. Although the period is very small in the 150th time zone, the provision of this first state can cancel the pressure reduction caused by controlling the valve A2V. The length of the 150th time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 152nd time zone that is the time zone from time t152 to time t151, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulating portion 122 is increased to the pressure P104 in the 151st time zone. For these reasons, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P104 in the 152nd time zone.

Next, in the 151st time slot | zone which is a time slot | zone of the time t151-the time t153, a 2nd state is implement | achieved by performing pressure reduction control. Here, in this example, a case where the pressure in the second pressure accumulating unit 122 is the pressure P104 at the time t151 will be described. Since the pressure in the second pressure accumulator 122 is the pressure P104 at time t151 in the previous 152 time zone, the fuel injection device 1 injects the fuel from the second pressure accumulator 122 into the combustion chamber CC in the 151st time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure of the fuel to be reduced from the pressure P104 to the pressure P103 according to the length of the 151st time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P104 to the pressure P103, that is, the length of the 151st time zone is based on the pressure P104, the pressure P103, and the above-described equation (1). Can be calculated.

The above-described time t152 may be arranged within the 151st time zone.

Next, in the 153rd time zone, which is the time zone from time t153 to time t154, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, in the 151st time zone, the pressure in the second pressure accumulating unit 122 is reduced from the pressure P104 to the pressure P103. For these reasons, the pressure in the second pressure accumulator 122 is maintained at the pressure P103 in the 153rd time zone.

Next, in the time period from time t154 to time t157, the fuel injection device 1 performs so-called pre-injection. For example, in the 154th time zone that is the time zone from time t154 to time t156, the fuel injection device 1 realizes the first state described above. In the 154th time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t154 and becomes the pressure P104. The period of the 154th time zone is so small as to compensate for the pressure reduction in the second pressure accumulating unit 122 by controlling the valve A2V, and the pressure increase with respect to the pressure P103 is small. Although the period of the 154th time zone is very small, by providing this first state, the decompression caused by controlling the valve A2V can be offset. The length of the 154th time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 155th time zone, which is the time zone from time t155 to time t157, the fuel injection device 1 realizes the second state by performing pressure reduction control. Here, in this example, a case where the pressure in the second pressure accumulating unit 122 is the pressure P104 at the time t155 will be described. Since the pressure in the second pressure accumulator 122 is the pressure P104 at time t155 in the previous 154 time zone, the fuel injection device 1 injects the fuel from the second pressure accumulator 122 into the combustion chamber CC in the 155th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure of the fuel to be reduced from the pressure P104 to the pressure P103 according to the length of the 155th time zone. The time required for the pressure in the second accumulator 122 to be reduced from the pressure P104 to the pressure P103, that is, the length of the 155th time zone is based on the pressure P104, the pressure P103, and the above-described equation (1). Can be calculated.

Note that the above-described time t156 may be arranged within the 155th time zone.

Next, in the 157th time zone, which is the time zone from time t157 to time t158, the fuel injection device 1 closes both the first valve 21 and the second valve 22. In the 155th time zone, the pressure in the second pressure accumulator 122 is reduced from the pressure P104 to the pressure P103. For these reasons, in the 157th time zone, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P103.

Next, in the 158th time zone, which is the time zone from time t158 to time t159, the fuel injection device 1 realizes the first state. In the 158th time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t158. For example, the pressure in the second pressure accumulating unit 122 is increased from the pressure P103 to the pressure P107 by the pressure increasing effect accompanying the movement of the fuel. The length of the 158th time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 159th time zone, which is the time zone from time t159 to time t160, the fuel injection device 1 opens both the first valve 21 and the second valve 22. The pressure in the second accumulator 122 has already been increased to the pressure P107 in the 158th time zone. For these reasons, in the 159th time zone, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P107 without increasing the pressure. The 159th time zone may be omitted.

  Next, in the 160th time zone that is the time zone from time t160 to time t161, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second accumulator 122 is the pressure P107 at time t160, the fuel injection device 1 at least supplies the pressure of the fuel injected from the second accumulator 122 into the combustion chamber CC in the 160th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure from P107 to the pressure P101 corresponding to the length of the 160th time zone. The time required for the pressure in the second pressure accumulating section 122 to be reduced from at least the pressure P107 to the pressure P101, that is, the length of the 160th time zone, is the pressure P107, the pressure P101, and the above-described equation (1). Can be calculated based on this.

Then, since the fuel injection device 1 closes the second valve 22 at the time t161, the fuel injection from the second pressure accumulating portion 122 into the combustion chamber CC stops and is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t161. On the other hand, since the fuel injection device 1 keeps the first valve 21 closed during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the pressure P101.

With the control method represented by the timing chart shown in FIG. 15, the fuel injection device 1 can perform each of the pilot injection, the pre-injection, the main injection, and the after injection described above while suppressing an increase in the fuel consumption rate. it can. In the example shown in FIG. 15, the fuel injection device 1 causes the pressure in the second pressure accumulator 122 when performing the pilot injection and the pre-injection to be a desired pressure higher than 0 and lower than the predetermined pressure P0. adjust. That is, the desired pressure is a pressure lower than the pressure of the fuel injected into the combustion chamber CC during the main injection. The fuel injection device 1 injects fuel into the combustion chamber CC at the desired pressure in each of the pilot injection, pre-injection, and main injection. Thereby, the fuel injection device 1 can reduce the amount of noise of the internal combustion engine EG, and can further reduce the amount of emission of the internal combustion engine EG. In this example, the fuel injection device 1 can adjust the pressure in the second pressure accumulator 122 at the time of pilot injection and pre-injection, and the main injection takes advantage of the unique characteristics of the reverse delta pattern. Control can be realized.

Although the horizontal axis of each graph shown in FIG. 15 is described as representing time, it can be replaced with a crank angle (crank angle) (not shown) of the internal combustion engine EG. In this case, FIG. 15 represents one period of the combustion cycle. In the above case, the ECU 3 may acquire information on the crank angle by a known method. The same applies to the following drawings.

FIG. 16 is a timing chart for explaining a specific example 12 of the control method of the fuel injection device 1. Specific example 12 of the control method is a control method for causing the fuel injection device 1 to perform multi-stage injection, for example, pilot injection, pre-injection, and main injection, by combining some or all of the control methods described above. It is. Note that the above control method does not limit the implementation of after-injection, and may be implemented as appropriate. The timing chart shown in FIG. 16 includes four graphs, graphs CH121 to CH124. Each horizontal axis of the graphs CH121 to CH124 represents time. Further, the vertical axis of the graph CH121 represents the state of the valve A1V. The vertical axis of the graph CH122 represents the pressure in the second pressure accumulating unit 122. Further, the vertical axis of the graph CH123 represents the state of the valve A2V. The vertical axis of the graph CH124 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. In addition, each of time t150, time t154, time t158, and time t162 in the graphs CH121 to CH124 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. . Further, at time t152, time t156, time t160, and time t163 in the graphs CH121 to CH124, the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 is closed. Represents the time. Each of time t151, time t155, and time t159 in the graphs CH121 to CH124 represents the time when the second valve 22 is opened when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2. In addition, each of time t153, time t157, and time t161 in the graphs CH121 to CH124 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. . Here, time t161 is a time before time t162, and time t162 is a time before time t163. Note that the description from the time t150 to the time t161 in the graphs CH121 to CH124 refers to the description of the eleventh embodiment shown in FIG. The difference from the eleventh embodiment shown in FIG. 15 is that the method for adjusting the pressure of the second pressure accumulator 122 for pilot injection and pre-injection is different. In Example 11 shown in FIG. 15, after the main injection, the pressure in the second pressure accumulating unit 122 is once increased to the pressure P107 prior to the pilot injection and the pre-injection, and then adjusted to a desired pressure. In the present embodiment, this is omitted, and after time t161, the pressure of the second pressure accumulating unit 122 is adjusted without pressurizing to the pressure P107 once. Hereinafter, pressure adjustment performed after time t161 will be described.

The fuel injection device 1 sequentially performs pilot injection, pre-injection, and main injection from time t150 to time t161.

Next, in the 161st time slot | zone which is a time slot | zone from the time t161 to the time t162, the fuel injection device 1 has closed both the 1st valve 21 and the 2nd valve 22. FIG. Further, the pressure in the second pressure accumulating unit 122 is reduced from the pressure P107 to the pressure P101 in the 161st time zone. For these reasons, the pressure in the second pressure accumulating section 122 is maintained at the pressure P101 in the 161st time zone. Further, since the fuel injection device 1 closes the second valve 22 at time t161, the fuel injection from the second pressure accumulating portion 122 into the combustion chamber CC stops and is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t161.

Next, in the 162nd time slot | zone which is a time slot | zone of the time t162-the time t163, the fuel injection apparatus 1 has implement | achieved the 1st state. In the 162nd time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t162. Further, the pressure of the fuel supplied to the second pressure accumulating unit 122 is the predetermined pressure P0. According to the dynamic effect due to the movement of the fuel, the pressure in the second pressure accumulating unit 122 can be increased up to, for example, the pressure P107, but in this example, the length of the 162nd time zone is relatively short. The time is determined, and the pressure in the second pressure accumulating portion 122 remains at a pressure increase up to at least the pressure P103 lower than the predetermined pressure P0. Note that the length of the 162nd time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, the fuel injection device 1 closes both the first valve 21 and the second valve 22 until the pilot injection timing of the next combustion cycle in the period after time t163. Thereby, the pressure in the 2nd pressure accumulation part 122 is maintained with the pressure P103.

With the control method represented by the timing chart shown in FIG. 16, the fuel injection device 1 can perform each of the pilot injection, the pre-injection, and the main injection described above while suppressing an increase in the fuel consumption rate. In the example illustrated in FIG. 16, the fuel injection device 1 causes the pressure in the second pressure accumulator 122 when performing the pilot injection and the pre-injection to be a desired pressure that is at least higher than 0 and lower than the predetermined pressure P0. Adjust to. That is, the desired pressure is lower than the pressure P107 of fuel injected into the combustion chamber CC during main injection. The fuel injection device 1 injects fuel into the combustion chamber CC at the desired pressure in each of the pilot injection, pre-injection, and main injection. Furthermore, the fuel injection device 1 can adjust the pressure in the second pressure accumulator 122 during the pilot injection and pre-injection without increasing the pressure to at least the predetermined pressure P0. Thereby, the fuel injection device 1 can reduce the amount of noise of the internal combustion engine EG, and can further reduce the amount of emission of the internal combustion engine EG. In this example, the fuel injection device 1 can adjust the pressure in the second pressure accumulator 122 at the time of pilot injection and pre-injection, and the main injection takes advantage of the unique characteristics of the reverse delta pattern. Control can be realized.

FIG. 17 is a timing chart for explaining a specific example 13 of the control method of the fuel injection device 1. Specific example 13 of the control method is a control method for causing the fuel injection device 1 to perform multi-stage injection, for example, pilot injection, pre-injection, and main injection, by combining some or all of the control methods described above. It is. Note that the above control method does not limit the implementation of after-injection, and may be implemented as appropriate. The timing chart shown in FIG. 17 includes four graphs of graph CH131 to graph CH134. Each horizontal axis of the graphs CH131 to CH134 represents time. Further, the vertical axis of the graph CH131 represents the state of the valve A1V. Further, the vertical axis of the graph CH132 represents the pressure in the second pressure accumulating unit 122. Further, the vertical axis of the graph CH133 represents the state of the valve A2V. The vertical axis of the graph CH134 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. Further, each of time t171, time t173, time t175, and time t177 in the graphs CH131 to CH134 represents the time when the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. . In addition, at time t172, time t174, time t176, and time t178 in the graphs CH131 to CH134, the supply of drive current from the first valve drive circuit 33 to the drive unit A1 is stopped, and the first valve 21 is closed. Represents the time. Further, a time t170 in the graph CH131 to the graph CH134 represents a time when the second valve 22 is opened when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2. Also, time t179 in the graphs CH131 to CH134 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, time t157 is a time before time t170, time t170 is a time before time t171, time t171 is a time before time t172, and time t172 is a time. The time is before t173, the time t173 is a time before the time t174, the time t174 is a time before the time t175, and the time t175 is a time before the time t176. The time t176 is a time before the time t177, the time t177 is a time before the time t178, and the time t178 is a time before the time t179. Further, each of the pressure P21, the pressure P101, the pressure P103, the pressure P104, and the pressure P105 in the graph CH132 and the graph CH134 is a pressure higher than 0 and lower than the predetermined pressure P0, and the pressure P107 is a pressure higher than the predetermined pressure P0. It is. The pressure P101 is lower than the pressure P103, the pressure P103 is lower than the pressure P104, and the pressure P104 is lower than the pressure P105. At least the pressure P21 is a pressure lower than the pressure P103.

Note that the description from the time t141 to the time t157 in the graph CH131 to the graph CH134 refers to the description of Example 11 shown in FIG. In addition, the case where the pressure in the 2nd pressure accumulation part 122 in the time t141 is the pressure P103 is illustrated. The pressure in the second pressure accumulator 122 at this time t141 may vary depending on the state of the previous fuel injection cycle. The main difference from the eleventh embodiment shown in FIG. 15 is that the method for adjusting the pressure of the second pressure accumulator 122 during main injection is different. Example 11 shown in FIG. 15 is an example of reverse delta type main injection, but this example is an example of delta type main injection. Hereinafter, the pressure adjustment performed after time t170 will be described.

Prior to the main injection, the fuel injection device 1 performs pressure adjustment for pilot injection and pre-injection from time t141 to time t148. Thereafter, each of pilot injection and pre-injection is sequentially performed from time t150 to time t157.

Further, in the 157th time zone, which is the time zone from time t157 to time t170, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulator 122 is reduced from the pressure P104 to the pressure P103 in the above-described 156th time zone. For these reasons, in the 157th time zone, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P103.

In the example shown in FIG. 17, the fuel injection device 1 realizes main injection in the time period from time t170 to time t179. For example, in the 170th time zone, which is the time zone from time t170 to time t171, the fuel injection device 1 realizes the second state by performing pressure reduction control. For this reason, in the 170th time zone, the fuel injection device 1 reduces the pressure in the second pressure accumulation portion 122 from the pressure P103 to the pressure P21 corresponding to the length of the 170th time zone. Fuel is injected into the combustion chamber CC. As a result, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the 170th time zone is the pressure P103 at time t170, and is reduced from the pressure P103 to the pressure P21 in the 170th time zone. . The time required for the pressure in the second accumulator 122 to be reduced from the pressure P103 to the pressure P21, that is, the length of the 170th time zone is based on the pressure P103, the pressure P21, and the above-described equation (1). Can be calculated.

Next, over the time period from time t171 to time t179, the fuel injection device 1 performs the delta type main injection shown in FIG. For the detailed description, refer to FIG. 7 and read time t31 to time t39 in FIG. 7 from time t171 to time t179.

In addition, the broken line shown in the range from time t170 to time t179 in the graph CH134 is a schematic representation of the pressure by the delta pattern. In actual control, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC decreases as shown by a solid line in the time period from time t178 to time t179. For example, in the time period from time t178 to time t179, the fuel injection device 1 reduces the pressure in the second pressure accumulator 122 to the pressure P103 according to the length from the predetermined pressure P0 to time t178 to time t179. The fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC. As a result, in the time period from time t178 to time t179, the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC is the predetermined pressure P0 at time t178, and the time from time t178 to time t179. In the belt, the pressure is reduced from a predetermined pressure P0 to a pressure P103. The time required for the pressure in the second pressure accumulator 122 to be reduced from the predetermined pressure P0 to the pressure P103, that is, the length of the time zone from the time t178 to the time t179, is the predetermined pressure P0, the pressure P103, It can be calculated based on the equation (1).

With the control method represented by the timing chart shown in FIG. 17, the fuel injection device 1 can adjust the pressure in the second pressure accumulator 122 during pilot injection and pre-injection, and the main injection has a delta pattern. Control that makes use of unique features can be realized.

FIG. 18 is a timing chart for explaining a specific example 14 of the control method of the fuel injection device 1. Specific example 14 of the control method is a control method for causing the fuel injection device 1 to perform multi-stage injection, for example, pilot injection, pre-injection, and main injection, by combining some or all of the control methods described above. It is. Note that the above control method does not limit the implementation of after-injection, and may be implemented as appropriate. The timing chart shown in FIG. 18 includes four graphs of graph CH141 to graph CH144. Each horizontal axis of the graphs CH141 to CH144 represents time. The vertical axis of the graph CH141 represents the state of the valve A1V. Further, the vertical axis of the graph CH142 represents the pressure in the second pressure accumulating unit 122. Further, the vertical axis of the graph CH143 represents the state of the valve A2V. The vertical axis of the graph CH144 represents the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC. In addition, from time t188 to time t193 in the graphs CH141 to CH144 are as follows. Each of the time t188 and the time t191 in the graph CH141 to the graph CH144 represents a time at which the first valve 21 is opened when the drive current is supplied from the first valve drive circuit 33 to the drive unit A1. Each of time t190 and time t193 in the graphs CH141 to CH144 represents the time when the supply of the drive current from the first valve drive circuit 33 to the drive unit A1 is stopped and the first valve 21 is closed. Further, time t189 in the graphs CH141 to CH144 represents the time when the second valve 22 is opened when the drive current is supplied from the second valve drive circuit 34 to the drive unit A2. Also, time t192 in the graphs CH141 to CH144 represents the time when the supply of the drive current from the second valve drive circuit 34 to the drive unit A2 is stopped and the second valve 22 is closed. Here, the time t188 is a time before the time t189, the time t189 is a time before the time t190, the time t190 is a time before the time t191, and the time t191 is a time This is a time before t192, and time t192 is a time before time t193. Moreover, each of the pressure P101, the pressure P103, the pressure P104, the pressure P105, and the pressure P108 in the graph CH142 and the graph CH144 is a pressure that is higher than 0 and lower than the predetermined pressure P0, and the pressure P107 is a pressure higher than the predetermined pressure P0. It is. The pressure P101 is lower than the pressure P108, the pressure P108 is lower than the pressure P103, the pressure P103 is lower than the pressure P104, and the pressure P104 is lower than the pressure P105. Pressure.

  For the description from time t141 to time t157 in the graph CH141 to the graph CH144, refer to the description of Example 11 shown in FIG. In addition, the case where the pressure in the 2nd pressure accumulation part 122 in the time t141 is the pressure P103 is illustrated. The pressure in the second pressure accumulator 122 at this time t141 may vary depending on the state of the previous fuel injection cycle. The main difference from the eleventh embodiment shown in FIG. 15 is that the method for adjusting the pressure of the second pressure accumulator 122 during main injection is different. Example 11 shown in FIG. 15 is an example of reverse delta type main injection, but this example is an example of V type main injection. Hereinafter, the pressure adjustment performed after time t188 will be described.

Note that the fuel injection device 1 performs pressure adjustment for pilot injection and pre-injection from time t141 to time t148 prior to main injection. Thereafter, each of pilot injection and pre-injection is sequentially performed from time t150 to time t157.

In addition, in the 157th time zone, which is the time zone from time t157 to time t188, the fuel injection device 1 closes both the first valve 21 and the second valve 22. Further, the pressure in the second pressure accumulating portion 122 is reduced from the pressure P104 to the pressure P103 in the above-described 155th time zone. For these reasons, in the 157th time zone, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P103.

In the example shown in FIG. 18, main injection is realized in the time period from time t188 to time t193. For example, in the 188th time zone from time t188 to time t189, the fuel injection device 1 realizes the first state. In the 188th time zone, the pressure in the second pressure accumulating unit 122 is increased according to the elapsed time from the time t188. For example, the pressure in the second pressure accumulating unit 122 is increased from the pressure P103 to the pressure P107 by the pressure increasing effect accompanying the movement of the fuel. The length of the 188th time zone is determined by the user in the same manner as the length of the 11th time zone.

Next, in the 189th time zone that is the time zone from time t189 to time t190, the fuel injection device 1 opens both the first valve 21 and the second valve 22. The pressure in the second accumulator 122 has already been increased to the pressure P107 in the 188th time zone. For these reasons, in the 189th time zone, the pressure in the second pressure accumulating portion 122 is maintained at the pressure P107 without increasing the pressure. The 159th time zone may be omitted.

Next, in the 190th time zone that is the time zone from time t190 to time t191, the fuel injection device 1 realizes the second state by performing pressure reduction control. Since the pressure in the second accumulator 122 is the pressure P107 at time t190, the fuel injection device 1 at least increases the pressure of the fuel injected from the second accumulator 122 into the combustion chamber CC in the 190th time zone. The fuel is injected from the second pressure accumulator 122 into the combustion chamber CC while reducing the pressure from P107 to a pressure P108 corresponding to the length of the 190th time zone. The time required for the pressure in the second pressure accumulating section 122 to be reduced from at least the pressure P107 to the pressure P108, that is, the length of the 190th time zone is expressed by the pressure P107, the pressure P108, and the above-described equation (1). Can be calculated based on this.

Next, in the 191st time zone, which is the time zone from time t191 to time t192, the fuel injection device 1 realizes the above-described third state by performing pressure increase control. In the 191st time zone, the pressure in the second pressure accumulating portion 122 is increased to the predetermined pressure P0. Since the first valve 21 remains open even during the 191st time zone, the fuel injection device 1 determines the pressure of the fuel injected from the second pressure accumulator 122 into the combustion chamber CC in the second pressure accumulator 122. The pressure is gradually increased to a pressure, and the fuel is injected from the second pressure accumulating portion 122 into the combustion chamber CC. The case shown in FIG. 18 is an example in which the pressure in the second pressure accumulating unit 122 reaches the predetermined pressure P0 before reaching the time t192. Then, since the fuel injection device 1 closes the second valve 22 at time t192, the fuel injection from the second pressure accumulator 122 into the combustion chamber CC stops and is injected from the second pressure accumulator 122 into the combustion chamber CC. The fuel pressure becomes 0 in the time zone after time t192. On the other hand, since the fuel injection device 1 keeps the first valve 21 open during the time period, the pressure in the second pressure accumulating unit 122 is maintained at the predetermined pressure P0. Note that the pressure in the second pressure accumulator 122 is adjusted to a suitable pressure by the time when pilot injection is started in the next combustion cycle.

With the control method represented by the timing chart shown in FIG. 18, the fuel injection device 1 can adjust the pressure in the second pressure accumulating unit 122 at the time of pilot injection and pre-injection. Control that makes use of unique features can be realized. In the case of this V-shaped pattern, as in the above-described concave pattern, the fuel injection device 1 burns in a later period in the period than in the previous period in which the fuel injection apparatus 1 is injecting fuel into the combustion chamber CC. Disturbed combustion of the fuel can be caused in the chamber CC. As a result, the fuel injection device 1 can reduce the amount of emissions generated from the internal combustion engine EG.

Here, the fuel injection device 1 injects fuel into the combustion chamber CC of the internal combustion engine EG by the various control methods described above. Such a fuel injection device 1 can change the pressure at which the fuel supplied from the high pressure source 4 at a predetermined pressure P0 is injected into the combustion chamber CC to a pressure equal to or lower than a predetermined pressure corresponding to each of at least three or more stages. It is. For example, the control unit 36 of the fuel injection device 1 divides the fuel into two or more stages so that the pressure of the fuel injected into the combustion chamber CC is different from each other, and injects the fuel from the fuel injector 2 at a pressure corresponding to the above-described stage. . The control unit 36 sets the above-described plurality of stages to, for example, 3 or more, so that, for example, a single main operation such as an injection start stage, a middle stage in the injection period, an end stage of the injection period, etc. An injection pattern in which the injection amount or the like changes with the passage of time from the start point of injection can be formed. Thereby, the fuel injection device 1 can change the pressure of the fuel injected into the combustion chamber to a pressure desired by the user while suppressing an increase in the fuel consumption rate.

The fuel injection device 1 can match the pattern of temporal change in the pressure of the fuel injected into the combustion chamber CC with any other pattern desired by the user.

For example, the fuel injection device 1 may control the fuel injector 2 by selecting a desired injection pattern as shown in FIG. FIG. 19 is a flowchart illustrating a procedure of an injection pattern selection process according to the embodiment.

Prior to the following processing, basic data for generating various injection patterns applicable to the fuel injection device 1 is stored in the storage unit 32. The control unit 36 reads basic data corresponding to the injection pattern from the storage unit 32 and controls the fuel injector 2 according to the basic data. For example, the injection pattern is selected according to the following procedure.

First, the control part 36 acquires the identification information of the injection pattern which should be selected (step S11). For example, the control unit 36 determines the identification information of the injection pattern to be selected based on the data related to the operation of the accelerator (not shown) by the user or the rotation speed of the internal combustion engine EG according to a predetermined rule, and the identification information May be obtained.

Next, the control part 36 determines the acquired identification information (step S12). Based on the determination result of step S12, the control unit 36 performs processing corresponding to the following case.

For example, when the identification information corresponds to a delta pattern, the control unit 36 reads basic data corresponding to the delta pattern from the storage unit 32 (step S13). If the identification information corresponds to the inverse delta pattern, the control unit 36 reads basic data corresponding to the inverse delta pattern from the storage unit 32 (step S14). If the identification information corresponds to the L-type pattern, the control unit 36 reads basic data corresponding to the L-type pattern from the storage unit 32 (step S15). If the identification information corresponds to the reverse L-shaped pattern, the control unit 36 reads basic data corresponding to the reverse L-shaped pattern from the storage unit 32 (step S16). When the identification information corresponds to the concave pattern, the control unit 36 reads basic data corresponding to the concave pattern from the storage unit 32 (step S17). When the identification information corresponds to the convex pattern, the control unit 36 reads basic data corresponding to the convex pattern from the storage unit 32 (step S18). When the identification information corresponds to the rectangular pattern, the control unit 36 reads basic data corresponding to the rectangular pattern from the storage unit 32 (step S19). If the identification information corresponds to the V-shaped pattern, the control unit 36 reads basic data corresponding to the V-shaped pattern from the storage unit 32 (step S20).

Next, the control unit 36 controls the pressure of the first pressure accumulating unit 112 in the fuel injector 2 based on the basic data read from the storage unit 32 in any of the processes from step S13 to step S20 (step S21). Then, the series of processing shown in the figure is completed. In addition, when the desired basic data is previously read from the memory | storage part 32, using it is not restrict | limited.

  By such processing, it is possible to select a desired injection pattern from the candidates to be selected and switch the injection pattern to be performed statically or dynamically. Instead, the fuel injection device 1 uses the delta pattern, the reverse delta pattern, the L pattern, and the reverse L pattern as the temporal change pattern of the pressure of the fuel injected from the second pressure accumulator 122. A pattern including at least one of a concave pattern, a convex pattern, a rectangular pattern, and a V-shaped pattern is also possible.

Each of the various patterns described in FIGS. 5 to 18 is an example of a pattern that can match the temporal change pattern of the pressure of the fuel injected into the combustion chamber CC by the fuel injection device 1. Only. The selection conditions in FIG. 19 may be changed according to the type of pattern applied to the fuel injection device 1.

  Further, the fuel injection device 1 changes the pressure of the fuel to be injected by a combination of the open / close state of the first valve 21 and the open / close state of the second valve 22. On the other hand, a fuel injection device (a fuel injection device different from the fuel injection device 1) provided with the above-described pressure increase mechanism changes the pressure of fuel to be injected by moving the pressure increase mechanism. The response time from when the fuel injection device 1 changes the drive current supplied to each of the first valve 21 and the second valve 22 to when the pressure of the fuel injected from the fuel injection device 1 changes depends on the fuel injection. It is shorter than the response time from when the device moves the pressure increasing mechanism until the pressure of the fuel injected from the fuel injection device changes. Due to such a difference in response time, the fuel injection device can match the pattern of temporal change in the pressure of the fuel injected into the combustion chamber CC with any other pattern desired by the user. May be difficult. For example, in the fuel injection device, the temporal change pattern of the pressure of the fuel injected by the fuel injection device is changed to a period of one main injection such as the concave pattern, the convex pattern, and the V-shaped pattern. It cannot be matched with a pattern in which pressure changes repeatedly in a short time. On the other hand, as described above, the fuel injection device 1 matches the pattern of the temporal change in the pressure of the fuel injected into the combustion chamber CC with any other pattern desired by the user. Can do. This is important because it leads to an improvement in the degree of freedom of design of the internal combustion engine EG.

  Moreover, each time demonstrated in each of FIGS. 5-18 represents the timing which the fuel-injection apparatus 1 switches to the state of either the state which each opened the 1st valve 21 and the 2nd valve 22, and closed. Yes. Then, the ECU 3 sets the first valve 21 and the second valve 22 to either the opened state or the closed state according to the timing stored in advance in the storage unit 32. The user stores the timing desired by the user in the storage unit 32 in advance, thereby causing the fuel injection device 1 to switch (open / close) the states of the first valve 21 and the second valve 22 at the timing desired by the user. . The data regarding said timing is contained in the basic data of various injection patterns. Here, in each of FIGS. 5 to 18, for convenience of explanation, the timing at which the fuel injection device 1 opens and closes each of the first valve 21 and the second valve 22 is described by time. However, the timing stored in advance in the storage unit 32 may be represented by an elapsed time from a reference time instead of the time, or may be represented by another known method, or a method to be developed in the future. May be represented by

As described above, the fuel injection device 1 according to the embodiment is a fuel injection device that injects fuel into the combustion chamber (in this example, the combustion chamber CC) of the internal combustion engine (in this example, the internal combustion engine EG). A pressure accumulator (in this example, the second accumulator 122) to which fuel is supplied from a high pressure source (in this example, the high pressure source 4) that supplies fuel at a predetermined pressure (in this example, the predetermined pressure P0); A first valve (in this example, the first valve 21) that supplies fuel supplied from a high-pressure source to the inside of the pressure accumulator, and a second valve that injects fuel supplied to the pressure accumulator from the pressure accumulator into the combustion chamber ( In this example, a second valve 22) is provided. Thereby, the fuel injection device 1 can change the pressure of the fuel injected into the combustion chamber to a pressure desired by the user while suppressing an increase in the fuel consumption rate.

  In addition, the fuel injection device 1 has at least a first drive unit (in this example, the drive unit A1) that makes at least the first valve in an open state or a closed state, and at least the state of the second valve. A second drive unit (in this example, the drive unit A2) that is in either an open state or a closed state, and a control unit (in this example, the control unit) that controls the first drive unit and the second drive unit. 36). Thereby, the fuel injection device 1 can change the pressure of the fuel injected into the combustion chamber to a pressure desired by the user while suppressing an increase in the fuel consumption rate by the control by the control unit.

Further, the fuel injection device 1 performs control including pressure reduction control of the pressure in the pressure accumulating unit by opening the second valve in a state where the first valve is closed. Thereby, the fuel injection device 1 can reduce the pressure of the fuel injected into the combustion chamber to a pressure desired by the user.

Further, in the fuel injection device 1, the amount of change in pressure per unit time in the pressure accumulating unit in the pressure reduction control is inversely proportional to the volume of the pressure accumulating unit and proportional to the amount of fuel injected from the pressure accumulating unit. Thereby, the fuel injection device 1 can reduce the pressure of the fuel injected into the combustion chamber to a pressure desired by the user at a speed according to the volume of the pressure accumulating unit and the amount of fuel injected from the pressure accumulating unit. it can.

Further, the fuel injection device 1 performs control including pressure increase control for opening the first valve in a state where the second valve is opened. As a result, the fuel injection device 1 can increase the pressure of the fuel injected into the combustion chamber to a pressure desired by the user up to a predetermined pressure, which is a pressure reduced by the fuel injection into the combustion chamber. it can.

In addition, the fuel injection device 1 uses a delta pattern, an inverse delta pattern, an L pattern, an inverted L pattern, a concave pattern, a convex pattern, as a temporal change pattern of the fuel pressure injected from the pressure accumulator. It is possible to make a pattern including at least one of a rectangular pattern and a V-shaped pattern. Thereby, the fuel injection device 1 can make the pattern of the time change of the pressure of the fuel injected from the pressure accumulating portion a pattern desired by the user.

The fuel injection device 1 is a fuel injection device that injects fuel into the combustion chamber of the internal combustion engine, and injects the fuel into the combustion chamber (in this example, the second opening 125), and the fuel is predetermined. A high-pressure source that supplies pressure to the injection unit, and a decompression unit (in this example, the second pressure accumulation unit 122) that reduces the pressure of the fuel provided between the injection unit and the high-pressure source. Thereby, the fuel injection device 1 can change the pressure of the fuel injected into the combustion chamber to a pressure desired by the user while suppressing an increase in the fuel consumption rate. In addition, as above-mentioned, the 2nd pressure accumulation part 122 is an example of a pressure reduction part. Such a second pressure accumulator 122 reduces the pressure of the fuel in the second pressure accumulator 122 at the time of fuel injection when the movement of the fuel to and from the high pressure source 4 is selectively interrupted. The fuel injection device 1 may limit the flow rate of the fuel by selecting a state in which the movement of the fuel is equal to or less than a predetermined amount, instead of the interruption. The second pressure accumulating unit 122 may form a pressure reducing unit by combining with the control unit 36.

The fuel injection device 1 is a fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine, and the pressure for injecting fuel supplied at a predetermined pressure from a high pressure source into the combustion chamber is at least three or more stages. The pressure can be changed to a pressure equal to or lower than a predetermined pressure corresponding to each. Thereby, the fuel injection device 1 can change the pressure of the fuel injected into the combustion chamber to a pressure desired by the user while suppressing an increase in the fuel consumption rate.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and changes, substitutions, deletions, and the like are possible without departing from the gist of the present invention. May be.

Further, a program for realizing the function of an arbitrary component in the above-described apparatus (for example, ECU 3) is recorded on a computer-readable recording medium, and the program is executed by being read by a computer system. May be. Here, the “computer system” includes hardware such as an OS (Operating System) and peripheral devices. The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD (Compact Disk) -ROM, or a storage device such as a hard disk built in the computer system. . Furthermore, “computer-readable recording medium” means a volatile memory (RAM) inside a computer system that becomes a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

In addition, the above program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Further, the above program may be for realizing a part of the functions described above. Further, the program may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

DESCRIPTION OF SYMBOLS 1 ... Fuel injection apparatus, 2 ... Fuel injector, 11 ... Electric injector, 12 ... Electric injector, 21 ... 1st valve, 22 ... 2nd valve, 31 ... CPU, 32 ... Memory | storage part, 33 ... 1st valve drive circuit, 34 ... second valve drive circuit, 36 ... control unit, 111 ... fuel supply conduit, 112 ... first pressure accumulating unit, 113 ... nozzle needle, 114A, 114B ... tip, 115 ... first opening, 121 ... fuel supply Pipe line, 122 ... second pressure accumulating part, 123 ... nozzle needle, 124A, 124B ... tip part, 125 ... second opening part, A1 ... drive part, A2 ... drive part, Bus ... bus, CC ... combustion chamber, CR ... Injection unit, EG ... internal combustion engine, PR1 ... high pressure source, PR2 ... accumulation unit, V1 ... first valve, V2 ... second valve, A1V, A2V ... valve

Claims (13)

A fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine,
A pressure accumulating unit to which the fuel is supplied from a high pressure source that supplies the fuel at a predetermined pressure;
A first valve for supplying the fuel supplied from the high-pressure source into the pressure accumulator;
A second valve for injecting the fuel supplied to the pressure accumulator from the pressure accumulator into the combustion chamber;
A fuel injection device comprising: A first drive unit that makes at least the state of the first valve either open or closed;
A second drive unit that makes at least the state of the second valve either open or closed;

A control unit for controlling the first drive unit and the second drive unit;
Further comprising
The fuel injection device according to claim 1. The control unit performs control including pressure reduction control of the pressure in the pressure accumulating unit by opening the second valve in a state where the first valve is closed.
The fuel injection device according to claim 2. The amount of change in pressure per unit time in the pressure accumulator in the pressure reduction control is inversely proportional to the volume of the pressure accumulator, and is proportional to the amount of fuel injected from the pressure accumulator.
The fuel injection device according to claim 3. The control unit performs control including pressure increase control for opening the first valve in a state where the second valve is opened.
The fuel injection device according to any one of claims 2 to 4. The control unit is configured to change a temporal change pattern of the pressure of the fuel injected from the pressure accumulating unit into a delta pattern, an inverted delta pattern, an L pattern, an inverted L pattern, a concave pattern, a convex pattern, a rectangle A pattern including at least one of a mold pattern and a V pattern,
The fuel injection device according to any one of claims 2 to 5. By controlling the state of the first valve, the fuel that has been pressurized to the predetermined pressure is moved from the high-pressure source to the pressure accumulating section via a pipeline, and the fuel moves in the pipeline. Due to the dynamic effect on the pressure of the fuel generated by the above, the pressure of the fuel in the pressure accumulating portion is increased above the predetermined pressure, and the fuel having a pressure higher than the predetermined pressure is injected into the combustion chamber by the second valve.
The fuel injection device according to claim 1. The first valve, the pressure accumulator, and the second valve are:
Between the high-pressure source and the injection unit that injects the fuel into the combustion chamber, the first valve, the pressure accumulating unit, and the second valve are provided in this order from the high-pressure source side, and at least the first valve Selectively limit the movement of the fuel from the high pressure source to the pressure accumulator to reduce the pressure of the fuel injected into the combustion chamber,
The fuel injection device according to claim 1. The valves of the first valve and the second valve are respectively switched between an opened state and a closed state under the control of the control unit, and the pressure of the fuel stored in the pressure accumulating unit is changed. Reduce the pressure to a pressure determined by the predetermined pressure and how to switch the state of each valve,
The second valve injects the fuel into the combustion chamber by the determined pressure with the second valve opened.
The fuel injection device according to claim 8. A fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine,
An injection unit for injecting the fuel into the combustion chamber;
A high pressure source for supplying the fuel to the injection unit at a predetermined pressure;
A pressure reducing unit that reduces the pressure of the fuel provided between the injection unit and the high pressure source;
A fuel injection device comprising: The decompression unit is
Provided between the injection unit and the high-pressure source, and the movement of the fuel between at least the high-pressure source is selectively interrupted to reduce the pressure of the fuel;
The fuel injection device according to claim 10. The pressure reducing unit includes at least a pressure accumulating unit,
At least the first valve provided on the upstream side of the pressure accumulator and the second valve provided on the downstream side of the pressure accumulator are opened and closed by the control of the controller. The pressure of the fuel in the pressure accumulating unit is reduced to a pressure determined by the predetermined pressure and a method of switching the state of each valve by the control,
The fuel injection device according to claim 10. A fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine,
The pressure at which the fuel supplied from a high pressure source at a predetermined pressure is injected into the combustion chamber can be changed to a pressure equal to or lower than the predetermined pressure corresponding to each of at least three stages.
Fuel injection device.

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