WO2023105919A1

WO2023105919A1 - Fuel injection device, fuel injection system, and control method

Info

Publication number: WO2023105919A1
Application number: PCT/JP2022/038216
Authority: WO
Inventors: 哲哉相澤; 泰三嶋田; 凌伍吉宇田; 諒平池田; 直輝芳賀; 晴天保井
Original assignee: 学校法人明治大学
Priority date: 2021-12-08
Filing date: 2022-10-13
Publication date: 2023-06-15
Also published as: JPWO2023105919A1

Abstract

This fuel injection device, which injects a fuel into a combustion chamber of an internal combustion engine, comprises: an injection port for injecting the fuel into the combustion chamber; a first flow passage which connects the injection port and a high-pressure source that supplies the fuel at a predetermined pressure, and to which the fuel is supplied from the high-pressure source; a first valve which is provided to the first flow passage and performs opening/closing of the injection port; a second flow passage which is connected to the first flow passage and to which the fuel is supplied from the first flow passage; and a second valve which is provided to the second flow passage and performs opening/closing of the second flow passage.

Description

FUEL INJECTION DEVICE, FUEL INJECTION SYSTEM, AND CONTROL METHOD

The present invention relates to a fuel injection device, a fuel injection system, and a control method.
This application claims priority based on Japanese Patent Application No. 2021-199326 filed in Japan on December 08, 2021, the contents of which are incorporated herein.

Research and development of technology to improve fuel combustion efficiency in fuel-injected internal combustion engines such as diesel engines is underway.

In this regard, a method is known in which a piezoelectric element drives a valve that opens and closes an injection port for injecting fuel into the combustion chamber of a fuel-injection internal combustion engine (see Patent Document 1).

Japanese Patent Application Laid-Open No. 2021-162009

A method such as that described in Patent Document 1 can improve the responsiveness to the control of opening and closing the injection port, and can sharpen the rise of the fuel injection rate. The steeper the rise of the fuel injection rate, the more the fuel combustion efficiency improves.

Here, the rise of the fuel injection rate can be made steeper by increasing the fuel injection pressure. This means that even if the method described in Patent Literature 1 is used, there is room for further improving the fuel combustion efficiency in a fuel-injection internal combustion engine. As a method of increasing the injection pressure of fuel, a method of increasing the pressure of a high-pressure source that supplies fuel into the combustion chamber is known. However, in order to raise the pressure of the high-pressure source, it is necessary to improve the pressure resistance of the entire system that supplies fuel into the combustion chamber. This is not preferable because it causes an increase in the weight of the internal combustion engine, an increase in the manufacturing cost of the internal combustion engine, and the like.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems of the prior art, and provides a fuel injection device, a fuel injection system, and a control method capable of injecting fuel at a pressure higher than the pressure of a high-pressure source. .

In order to solve the above-described problems, 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, comprising: an injection port that injects the fuel into the combustion chamber; a first flow path for connecting a high-pressure source for supplying the fuel at a predetermined pressure to the injection port, and for supplying the fuel from the high-pressure source; a first valve that opens and closes; a second flow path that is connected to the first flow path and to which the fuel is supplied from the first flow path; and a second valve that opens and closes.

Further, in order to solve the above-described problems, 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, the fuel injection device injecting the fuel into the combustion chamber. a first flow path connecting a port, a high-pressure source for supplying the fuel at a predetermined pressure, and the injection port, and supplied with the fuel from the high-pressure source; a first valve for opening and closing a port; a second flow path connected to the first flow path and supplied with the fuel from the first flow path; a second valve that opens and closes a passage; a portion that is provided in the first passage and is located upstream of the first valve in the first passage among portions of the first passage; and a third valve that opens and closes a portion of the first flow path located downstream of a connection portion between the first flow path and the second flow path in the first flow path; wherein the fuel is held in the first flow path when the first valve closes the injection port and the third valve closes the first flow path space is formed.

Further, in order to solve the above-described problems, a fuel injection system according to one aspect of the present invention includes a first fuel injection device that injects fuel into a combustion chamber of an internal combustion engine, and a first fuel injection device that injects the fuel into the combustion chamber. 2 a fuel injection device, a 0th flow path connected to a high-pressure source that supplies the fuel at a predetermined pressure and to which the fuel is supplied from the high-pressure source; and a second valve provided in the second flow path for opening and closing the second flow path, wherein the first fuel injection device supplies the fuel. an eleventh injection port for injecting into the combustion chamber; an eleventh passage connecting the zeroth flow passage and the eleventh injection port; and an eleventh valve for opening and closing the eleventh injection port, and the second fuel injection device includes a twenty-first injection port for injecting the fuel into the combustion chamber, the zeroth flow path, a 21st flow path connected to a 21st injection port and supplied with the fuel from the high pressure source; and a 21st valve provided in the 21st flow path for opening and closing the 21st injection port. .

Further, in order to solve the above-described problems, a control method according to an aspect of the present invention is a control method for a fuel injection device that injects fuel into a combustion chamber of an internal combustion engine, wherein the fuel injection device includes the fuel into the combustion chamber, a high-pressure source for supplying the fuel at a predetermined pressure, and the injection port are connected to each other, and a first flow path to which the fuel is supplied from the high-pressure source; a first valve provided in a flow path for opening and closing the injection port; a first driving unit for causing the first valve to open and close the injection port; a second flow passage to which the fuel is supplied from the passage; a second valve provided in the second flow passage for opening and closing the second flow passage; and a second drive unit that causes the first valve to open the second flow path in a state in which the first valve closes the injection port; a second step of closing the second flow path by the second valve after a predetermined time has elapsed since the second valve opened the second flow path in the step; and a third step of opening the injection port by the first valve at a timing after closing the second flow path.

Further, in order to solve the above-described problems, a control method according to an aspect of the present invention is a control method for a fuel injection device that injects fuel into a combustion chamber of an internal combustion engine, wherein the fuel injection device includes the fuel into the combustion chamber, a high-pressure source for supplying the fuel at a predetermined pressure, and the injection port are connected to each other, and a first flow path to which the fuel is supplied from the high-pressure source; a first valve provided in a flow path for opening and closing the injection port; a first driving unit for causing the first valve to open and close the injection port; a second flow passage to which the fuel is supplied from the passage; a second valve provided in the second flow passage for opening and closing the second flow passage; and a portion of the portion of the first flow path that is located upstream of the first valve in the first flow path, and that of the portion of the first flow path. a third valve provided in a portion of the first flow path located downstream of a connection portion between the first flow path and the second flow path to open and close the first flow path; and a third drive unit that causes three valves to open and close the first flow path, and the first valve is in a state where the injection port is closed in the first flow path, and the third When the valve closes the first flow path, a space is formed in which the fuel is held, and the control method includes controlling the second flow path with the third valve closing the first flow path. an eleventh step of opening the second flow path with a valve; and after a predetermined first time has elapsed since the second valve opened the second flow path in the eleventh step, a twelfth step of closing two flow paths; a thirteenth step of opening the first flow path by the third valve at a timing after the second valve closes the second flow path in the twelfth step; During the period from when the second valve closes the second flow path in the twelfth step to when the third valve opens the first flow path in the thirteenth step, the injection port is operated by the first valve. and a fourteenth step of opening

According to the present invention, it is possible to provide a fuel injection device, a fuel injection system, and a control method that can inject fuel at a pressure higher than the pressure of a high-pressure source.

1 is a diagram showing an example of a configuration 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 functional structure of ECU3. The opening and closing timings of the injection port H and the second flow path F2 in the fuel injection device 1, the temporal change of the pressure in the first flow path F1, the temporal change of the lift amount of the first valve V1, FIG. 4 is a diagram showing an example of temporal changes in fuel injection pressure and temporal changes in fuel injection rate. The opening and closing timings of the injection port H and the second flow path F2 in the fuel injection device 1A, the temporal change of the pressure in the first flow path F1, the temporal change of the lift amount of the first valve V1, FIG. 4 is a diagram showing an example of temporal changes in fuel injection pressure and temporal changes in fuel injection rate; FIG. 5 is a diagram showing another example of the configuration of the fuel injection device 1B; It is a figure showing other examples of functional composition of ECU3. The opening and closing timings of the injection port H, the first flow path F1, and the second flow path F2 in the fuel injection device 1B, the temporal change of the pressure in the first flow path F1, and the temporal change in the pressure in the space S FIG. 2 is a diagram showing an example of each of a change over time, a change over time in the lift amount of the first valve V1, a change over time in the injection pressure of fuel, and a change over time in the injection rate of fuel. The opening and closing timings of the injection port H, the first flow path F1, and the second flow path F2 in the fuel injection device 1C, the temporal change in the pressure in the first flow path F1, and the temporal change in the pressure in the space S FIG. 2 is a diagram showing an example of each of a change over time, a change over time in the lift amount of the first valve V1, a change over time in the injection pressure of fuel, and a change over time in the injection rate of fuel. 1 is a diagram showing an example of a configuration of a fuel injection system 10; FIG. An example of opening/closing timing of the second flow path F2, opening/closing timing of the injection port H of each of the four fuel injection devices 1D, and temporal change in pressure in the four first flow paths F1 is shown. It is a diagram.

<Embodiment>
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, shortening of the time from the timing when a certain physical quantity starts to increase to the timing when the physical quantity reaches the maximum value is referred to as steep rise of the physical quantity. Further, in the present embodiment, an increase in the maximum value of the physical quantity will be described as a sharp rise of the physical quantity. The physical quantity is, for example, a fuel injection pressure, a fuel injection rate, etc., which will appear below, but is not limited to these.

<Overview of Fuel Injector>
First, an overview of the fuel injection device 1 according to the embodiment will be described.

The fuel injection device 1 is provided in the fuel injection type internal combustion engine EG, and is a device that 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, for example, a diesel engine provided in automobiles, ships, railway vehicles, heavy machinery, and the like. Thus, the fuel is light oil in this example. The internal combustion engine EG may be another fuel injection type internal combustion engine such as a fuel injection type gasoline engine instead of the diesel engine.

Here, as a method of increasing the fuel combustion efficiency in the internal combustion engine EG, a method of increasing the injection pressure of fuel into the combustion chamber CC is known. This can be achieved, for example, by increasing the pressure of the high pressure source that supplies fuel into the combustion chamber CC. However, in order to increase the pressure of the high-pressure source, it is necessary to improve the pressure resistance of the entire system that supplies fuel into the combustion chamber CC. This is not preferable because it causes an increase in the weight of the internal combustion engine EG, an increase in the manufacturing cost of the internal combustion engine EG, and the like.

Therefore, the fuel injection device 1 includes an injection port, a first flow path, a first valve, a second flow path, and a second valve. The injection port is an opening through which fuel is injected into the combustion chamber CC. The first flow path connects a high-pressure source (common rail) that supplies fuel at a predetermined pressure to the injection port, and fuel is supplied from the high-pressure source. The predetermined pressure is the reference pressure in the fuel injection device 1 . The first valve is provided in the first flow path and opens and closes the injection port. The second flow path is connected to the first flow path and supplied with fuel from the first flow path. The second valve is provided in the second flow path and opens and closes the second flow path. As a result, the fuel injection device 1 can block the flow of fuel to the second flow path by closing the second flow path with the second valve while the injection port is closed with the first valve. In this case, the pressure in the first flow path momentarily becomes higher than the predetermined pressure due to the water hammer effect of the dammed fuel. As a result, the fuel injection device 1 opens the injection port during the period in which the pressure in the first flow path is higher than the predetermined pressure, thereby injecting fuel into the combustion chamber CC at a pressure higher than the predetermined pressure. can be injected into The higher the initial injection pressure of the fuel, the steeper and sharper the rise of the injection rate of the fuel injected into the combustion chamber CC. That is, the fuel injection device 1 can further improve the fuel combustion efficiency. Here, in the internal combustion engine EG, when the fuel combustion efficiency is improved, the fuel consumption rate per unit time is decreased according to the combustion state in the combustion chamber CC. Therefore, the fuel injection device 1 can also improve user convenience. The configuration of the fuel injection device 1 and the control method of the fuel injection device 1 will be described in detail below.

<Structure of Fuel Injector>
The configuration of the fuel injection device 1 according to the embodiment will be described below.

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

Fuel is supplied to the fuel injector 2 from a high pressure source 4 at a predetermined pressure Pb. Here, the high pressure source 4 is a common rail provided in the internal combustion engine EG. The fuel injector 2 injects the fuel supplied from the high pressure source 4 into the combustion chamber CC under the control of the ECU 3 . The high pressure source 4 is provided with a common rail pressure regulating valve (pressure relief valve). However, in FIG. 1, the illustration of the common rail pressure regulating valve is omitted for the sake of simplification.

The fuel injector 2 is, for example, an electric injector. The fuel injector 2 includes a first flow path F1, an injection port H, a first valve V1, a driving portion A1, a second flow path F2, a second valve V2, and a driving portion A2.

The first flow path F1 is a pipeline formed inside the housing of the fuel injector 2 . The first flow path F1 is a conduit through which fuel supplied from the high pressure source 4 at a predetermined pressure Pb passes. Further, the first flow path F1 is a pipeline that connects the high pressure source 4 and the injection port H. As shown in FIG. That is, fuel supplied from the high-pressure source 4 at a predetermined pressure Pb reaches the injection port H through the first flow path F1.

The injection port H is an opening formed in the first flow path F1. Therefore, the fuel supplied from the high-pressure source 4 to the first flow path F1 is injected (supplied) from the injection port H into the combustion chamber CC. That is, the injection port H injects fuel into the combustion chamber CC.

The first valve V1 is provided in the first flow path F1 and opens and closes the injection port H. In this embodiment, the state in which the injection port H is open means a state in which the fuel supplied from the first flow path F1 can be injected from the injection port H into the combustion chamber CC. Further, in the present embodiment, a state in which the injection port H is closed means a state in which the fuel supplied from the first flow path F1 cannot be injected from the injection port H into the combustion chamber CC. Therefore, the opening and closing of the injection port H may be realized by opening and closing the injection port H itself, or by opening and closing the first flow path F1. In the following, as an example, the opening and closing of the injection port H is realized by opening and closing the injection port H itself.

In the example shown in FIG. 1, the first valve V1 is a nozzle needle. Note that the first valve V1 may be any member as long as it is a member capable of opening and closing the injection port H instead of the nozzle needle.

The first valve V1 closes the injection port H by closing the injection port H with the tip of the first valve V1. More specifically, the first valve V1 does not move while blocking the injection port H when the ECU 3 does not drive the drive unit A1. This causes the first valve V1 to keep the injection port H closed in that case. On the other hand, the first valve V1 moves away from the injection port H when the ECU 3 drives the driving portion A1. As a result, the first valve V1 is in that case moved away from the injection port H in that direction, and the injection port H opens.

The drive unit A1 causes the first valve V1 to open and close the injection port H. The drive unit A1 has, for example, a solenoid, a piezo element, or the like as an actuator for driving the first valve V1. When the drive unit A1 is not driven by the ECU 3, the pressure of the fuel supplied through the pipe line connected to the first flow path F1 (that is, the predetermined pressure Pb) pushes the tip of the first valve V1. Continue to block the injection port H by pressing it against the injection port H. That is, the driving part A1 keeps the injection port H closed by the first valve V1 in this case. Here, the pipeline connects the first flow path F1 and an outlet through which the fuel passing through the pipeline is discharged. This outlet is connected, for example, to a fuel tank (this fuel tank may or may not be connected to the high pressure source 4) via a conduit (not shown). Therefore, the fuel flowing out from this outlet eventually returns to the fuel tank. It should be noted that the configuration beyond this discharge port may be replaced with any other configuration. Therefore, further detailed description of the configuration beyond this discharge port will be omitted. On the other hand, when the drive unit A1 is driven by the ECU 3, the pressure of the fuel supplied through the pipeline (that is, the predetermined pressure Pb) is reduced by opening the valve provided in the drive unit A1. , moves the first valve V1 away from the injection port H. That is, the driving part A1 opens the injection port H by the first valve V1 in this case. The structure and operation for opening and closing the first valve V1 may be a known structure and operation, or may be a structure and operation to be developed in the future, so further detailed description will be omitted.

The second flow path F2 is a pipeline formed inside the housing of the fuel injector 2. Also, the second flow path F2 is a conduit connecting the first flow path F1 and an outlet through which the fuel passing through the second flow path F2 is discharged. In other words, the second flow path F2 is a conduit connected to the first flow path F1. Therefore, fuel is supplied from the first flow path F1 to the second flow path F2. Here, for example, this outlet is connected to a fuel tank (this fuel tank may or may not be connected to the high pressure source 4) via a conduit (not shown). . Therefore, the fuel flowing out from this outlet through the second flow path F2 finally returns to the fuel tank. It should be noted that the configuration beyond this discharge port may be any configuration instead of this. Therefore, further detailed description of the configuration beyond this discharge port is omitted.

The second valve V2 is provided in the second flow path F2 and opens and closes the second flow path F2. In the present embodiment, when the second flow path F2 is open, the fuel supplied from the first flow path F1 flows through the second flow path F2 to the outlet through which the fuel passing through the second flow path F2 is discharged. means flowing through. Further, in the present embodiment, when the second flow path F2 is closed, the fuel supplied from the first flow path F1 is discharged from the second flow path F2 to the outlet through which the fuel passing through the second flow path F2 is discharged. It means no flow through F2. Therefore, the opening and closing of the second flow path F2 may be realized by opening and closing the second flow path F2 itself, or may be realized by opening and closing the connecting portion between the first flow path F1 and the second flow path F2. . In the following, as an example, a case where opening and closing of the second flow path F2 is realized by opening and closing of the second flow path F2 itself will be described. Here, it can also be said that the second valve V2 is a valve that changes the pressure in the first flow path F1 by opening and closing the second flow path F2. However, the second valve V2 is a valve additionally provided in the second flow path F2 separately from the common rail pressure regulating valve, and is not a valve functioning as a common rail pressure regulating valve. The common rail pressure regulating valve is a valve that releases fuel from the high-pressure source 4, which is a source of pressure, so that the high-pressure source 4 does not malfunction when the pressure of the high-pressure source 4 rises too much. A common rail pressure regulating valve is therefore usually provided in the high pressure source 4 itself. On the other hand, the position of the connecting portion between the first flow path F1 and the second flow path F2 is preferably closer to the injection port H. Also, the closer the position of the second valve V2 is to the injection port H, the better. This is because it is desired to increase the pressure of the fuel injected into the combustion chamber CC from the injection port H by the above-described water hammer action. Furthermore, using the second valve V2 instead of the common rail pressure regulating valve means that the pressure in the first flow path F1 changes irregularly, and the pressure in the first flow path F1 becomes unstable. It is not appropriate because it leads to For the above reasons, the fuel injection device 1 is provided with the second valve V2 as an additional valve separate from the common rail pressure regulating valve.

The second valve V2 may be any member as long as it is a member that can open and close the second flow path F2 according to the drive of the driving part A2. Therefore, in FIG. 1, the second valve V2 is indicated by a rectangle for convenience.

The second valve V2 closes the second flow path F2 by blocking the second flow path F2. More specifically, the second valve V2 closes the second flow path F2 and, as a result, closes the second flow path F2 when the ECU 3 does not drive the drive unit A2. On the other hand, when the ECU 3 drives the drive unit A2, the second valve V2 moves in the direction of opening the second flow path F2, opening the second flow path F2.

The drive unit A2 causes the second valve V2 to open and close the second flow path F2. The drive unit A2 has, for example, a solenoid, a piezo element, or the like as an actuator for driving the second valve V2. When not driven by the ECU 3, the driving part A2 does not move the second valve V2 and continues to close the second flow path F2. On the other hand, when driven by the ECU 3, the drive unit A2 moves the second valve V2 in the direction of opening the second flow path F2 to open the second flow path F2. The structure and operation for opening and closing the second valve V2 may be a known structure and operation, or may be a structure and operation that will be developed in the future, so further detailed description will be omitted.

<ECU functional configuration>
Hereinafter, with reference to FIG. 2, the functional configuration of the ECU 3 will be described. FIG. 2 is a diagram showing an example of the hardware configuration of the ECU 3. As shown in FIG. The ECU 3 includes, for example, a CPU (Central Processing Unit) 31, a storage section 32, a first valve drive circuit 33, and a second valve drive circuit . These components are communicatively connected to each other via a bus. Moreover, the structure provided with the communication part for mutually communicating with other ECU may be sufficient as ECU3.

The CPU 31 executes various programs stored in the storage section 32 . Note that the CPU 31 may be another processor such as an FPGA (Field Programmable Gate Array).
The storage unit 32 includes, for example, EEPROM (Electrically Erasable Programmable Read Only Memory), ROM (Read Only Memory), 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 drive current to the drive unit A1 for driving the drive unit A1 that opens and closes the first valve V1.
The second valve drive circuit 34 supplies a drive current for driving the drive section A2 that opens and closes the second valve V2 to the drive section A2.

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

The control unit 36 controls the first valve driving circuit 33 and causes the driving unit A1 to open and close the injection port H by the first valve V1 according to the timing stored in the storage unit 32 in advance. Further, the control unit 36 controls the second valve drive circuit 34 and causes the drive unit A2 to open and close the second flow path F2 by the second valve V2 according to the timing stored in advance in the storage unit 32 . The control unit 36 is implemented, for example, by the CPU 31 executing a program stored in the storage unit 32 . Also, the control unit 36 may be a hardware function unit such as LSI (Large Scale Integration) or ASIC (Application Specific Integrated Circuit).

<Control Method of Fuel Injector>
A specific example of the control method of the fuel injection device 1 will be described below with reference to FIG. In the following, as an example, when the driving current C1 is supplied to the driving part A1, the driving part A1 opens the injection port H by the first valve V1, and when the driving current C2 is supplied to the driving part A2, the driving is performed. A case where the part A2 opens the second flow path F2 by the second valve V2 will be described. That is, the driving portion A1 closes the injection port H by the first valve V1 when the supply of the driving current C1 to the driving portion A1 is stopped. Further, when the supply of the driving current C2 to the driving portion A2 is stopped, the driving portion A2 closes the second flow path F2 by the second valve V2. Moreover, below, the control method of the fuel-injection apparatus 1 in the case of performing main injection is demonstrated as an example. However, this control method may be applied to other injections such as pre-injection and pilot injection. In the following description, among the controls of the fuel injection device 1, the control involving the opening/closing of the injection port H and the opening/closing of the second flow path F2 will be referred to as the first control. In the following, as an example, among the controls of the fuel injection device 1, the control that accompanies the opening and closing of the injection port H and does not accompany the opening and closing of the second flow path F2 will be referred to as the second control. When the second control is performed, temporal changes in the fuel injection pressure and injection rate in the fuel injection device 1 are substantially the same as temporal changes in the fuel injection pressure and injection rate in the conventional fuel injection device. Gone. For this reason, comparing the control method of the fuel injection device 1 by the first control and the control method of the fuel injection device 1 by the second control is a different fuel injection device from the fuel injection device 1 (for example, a conventional fuel injection device). ), the superiority of the fuel injection device 1 can be clearly shown. Therefore, below, the control method of the fuel injection device 1 by the first control and the control method of the fuel injection device 1 by the second control will be compared, and the advantages of the fuel injection device 1 as compared with the conventional fuel injection device will be described. will be explained. In this embodiment, the fuel injection pressure indicates the fuel pressure at the injection port H outlet. Further, in the present embodiment, the fuel injection rate indicates the volume of fuel that flows out from the injection port H toward the combustion chamber CC per unit time.

FIG. 4 shows the opening and closing timings of the injection port H and the second flow path F2 in the fuel injection device 1, the temporal change of the pressure in the first flow path F1, and the temporal change of the lift amount of the first valve V1. FIG. 3 is a diagram showing an example of each of a change in pressure, a change in fuel injection pressure over time, and a change in fuel injection rate over time. Here, the lift amount of the first valve V1 is calculated by taking the position of the first valve V1 that blocks the injection port H as a reference position of the first valve V1 and comparing the reference position with the position of the first valve V1. It is the amount that indicates the difference between That is, as the lift amount of the first valve V1 increases, the opening degree of the injection port H increases. The position of the first valve V1 is represented by the position at the tip of the first valve V1, for example, but may be represented by the position of other parts of the first valve V1.

　The horizontal axis of each of the graphs G1 to G4 shown in FIG. However, in the example shown in FIG. 4, the timing at which the injection port H of the fuel injection device 1 controlled by the first control begins to open and the timing at which the injection port H of the fuel injection device 1 controlled by the second control begins to open. timing. Further, in this example, the timing at which the injection port H is closed in the fuel injection device 1 controlled by the first control is matched with the timing at which the injection port H is closed in the fuel injection device 1 controlled by the second control. ing. By matching these timings, FIG. 4 clearly shows the difference between the fuel injection device 1 controlled by the first control and the fuel injection device 1 controlled by the second control.

The vertical axis of the graph G1 shown in FIG. 4 indicates the pressure inside the first flow path F1. A curve FN1 plotted on the graph G1 shows an example of temporal change in pressure in the first flow path F1 when the fuel injection device 1 is controlled by the first control. On the other hand, a curve FX1 plotted in the graph G1 shows an example of temporal change in pressure in the first flow path F1 when the fuel injection device 1 is controlled by the second control. Also, a timing chart TC1 showing the opening/closing timing of the injection port H and a timing chart TC2 showing the opening/closing timing of the second flow path F2 are superimposed on the graph G1.

The vertical axis of the graph G2 shown in FIG. 4 indicates the lift amount of the first valve V1. A curve FN2 plotted on the graph G2 shows an example of temporal changes in the lift amount of the first valve V1 when the fuel injection device 1 is controlled by the first control. On the other hand, a curve FX2 plotted on the graph G2 shows an example of temporal change in the lift amount of the first valve V1 when the fuel injection device 1 is controlled by the second control.

The vertical axis of graph G3 shown in FIG. 4 indicates the fuel injection pressure. A curve FN3 plotted on the graph G3 shows an example of temporal changes in the fuel injection pressure when the fuel injection device 1 is controlled by the first control. On the other hand, a curve FX3 plotted on the graph G3 shows an example of temporal change in fuel injection pressure when the fuel injection device 1 is controlled by the second control.

The vertical axis of graph G4 shown in FIG. 4 indicates the fuel injection rate. A curve FN4 plotted on the graph G4 shows an example of temporal changes in the fuel injection rate when the fuel injection device 1 is controlled by the first control. On the other hand, a curve FX4 plotted on the graph G4 shows an example of temporal changes in the fuel injection rate when the fuel injection device 1 is controlled by the second control.

In the example shown in FIG. 4, the fuel injection device 1 controlled by the first control waits with the injection port H and the second flow path F2 closed until timing t1. Then, the fuel injection device 1 starts to open the second flow path F2 at the timing t1. As a result, as indicated by the curve FN1, in the fuel injection device 1, the pressure inside the first flow path F1 begins to decrease at timing t1. This is because the fuel starts to flow from the first flow path F1 to the second flow path F2 at the timing t1.

After that, in the fuel injection device 1 controlled by the first control, the driving section A2 starts moving the second valve V2 so that the second flow path F2 is closed at timing t2 when a predetermined first time has elapsed from timing t1. . As a result, in the fuel injection device 1, the pressure inside the first flow path F1 starts to rise at timing t2.

Then, in the fuel injection device 1 controlled by the first control, the pressure in the first flow path F1 momentarily becomes higher than the predetermined pressure Pb at the timing after the timing t2. This is because the fuel flowing from the first flow path F1 through the second flow path F2 to the discharge port is dammed by the second valve V2, and the resulting water hammer action causes the fuel to flow into the first flow path F1. This phenomenon occurs because the pressure momentarily becomes higher than the predetermined pressure Pb. More specifically, the fuel flowing from the first flow path F1 to the discharge port through the second flow path F2 is blocked by the second valve V2 in the second flow path F2 at timing t2. The dammed fuel is compressed according to the flow velocity of the fuel before dammed. As a result, a water hammer action occurs, and the pressure in the first flow path F1 begins to rise.

However, as indicated by the curve FN1, the pressure in the first flow path F1 damps and oscillates after timing t2. Therefore, the fuel injection device 1 controlled by the first control starts opening the injection port H at timing t3. At timing t3, among the timings after timing t2, the pressure in the first flow path F1 rises from the pressure less than the predetermined pressure Pb to the pressure exceeding the predetermined pressure Pb, and then the pressure in the first flow path F1 Any timing may be used as long as it is within the period until starts to fall again. Here, in FIG. 4, ΔPmax indicates the difference between the highest pressure due to the water hammer action and the predetermined pressure Pb among the pressures in the first flow path F1. That is, the fuel injection device 1 sets the timing within the period until the pressure in the first flow path F1 becomes (Pb+ΔPmax) among timings after the timing t2 as the timing t3, and the injection port H is injected at the timing t3. start to open. In the example shown in FIG. 4, the timing t3 is the timing after the timing t2 when the pressure in the first flow path F1 returns from the pressure lower than the predetermined pressure Pb to the predetermined pressure Pb.

The time difference between the timing t2 and the timing t3 is determined, for example, by trial and error in advance tests, experiments, etc., so that the combustion efficiency of the fuel approaches the desired combustion efficiency (for example, the highest combustion efficiency, etc.). , may be determined based on theoretical calculation, may be determined by simulation, or may be determined by other methods. Since the injection port H starts to open at the timing t3 determined in this way, the fuel in the first flow path F1 flows from the injection port H into the combustion chamber CC at the timing t3 at a pressure higher than the predetermined pressure Pb. begins to be sprayed into Therefore, the fuel injection pressure and injection rate also start to rise at timing t3, as indicated by curves FN3 and FN4, respectively.

After the timing t3, in the fuel injection device 1 controlled by the first control, the driving section A1 moves the first valve V1 so that the injection port H is closed at the timing t4 when a predetermined second time has elapsed from the timing t3. start. Triggered by the drive unit A1 starting to move the first valve V1, the fuel injection device 1 reduces the lift amount of the first valve V1 and increases the amount of fuel during the period from timing t3 to timing t4. Injection pressure and injection rate begin to drop. At timing t4, in the fuel injection device 1, the lift amount of the first valve V1 becomes 0 [mm], the fuel injection pressure becomes 0 [MPa], and the fuel injection rate becomes 0 [mm ³ /s]. becomes. However, in the period from timing t3 to timing t4, oscillations may be observed in each of the lift amount of the first valve V1, the fuel injection pressure, and the fuel injection rate. In the example shown in FIG. 4, each of the lift amount of the first valve V1, the fuel injection pressure, and the fuel injection rate fluctuates in the order of rising, falling, rising, and falling within the period. Therefore, in this example, two peaks appear in the temporal changes in the lift amount of the first valve V1, the fuel injection pressure, and the fuel injection rate. This is a reflection of the influence of the damped oscillation of the pressure in the first flow path F1 during this period. Countermeasures against this influence will be described in modification 1 and subsequent embodiments of the embodiment.

After timing t4, the fuel injection device 1 controlled by the first control waits with the injection port H and the second flow path F2 closed until the next injection of fuel is started. Therefore, in the fuel injection device 1, the pressure in the first flow path F1 returns to the predetermined pressure Pb until the next injection of fuel is started.

On the other hand, in the example shown in FIG. 4, as shown in the timing chart TC1, the fuel injection device 1 controlled by the second control keeps the injection port H and the second flow path F2 closed until timing t3. stand by. Then, the fuel injection device 1 starts to open the injection port H at timing t3. Since the injection port H begins to open, the fuel in the first flow path F1 begins to be injected from the injection port H into the combustion chamber CC at a predetermined pressure Pb at timing t3. Therefore, the fuel injection pressure and injection rate also start to rise at timing t3, as indicated by curves FX3 and FX4, respectively. As a result, as indicated by the curve FX1, in the fuel injection device 1, the pressure in the first flow path F1 starts to decrease from the predetermined pressure Pb at timing t3.

After timing t3, in the fuel injection device 1 controlled by the second control, the driving section A1 starts moving the first valve V1 so that the injection port H is closed at timing t4. Triggered by the drive unit A1 starting to move the first valve V1, the fuel injection device 1 reduces the lift amount of the first valve V1 and increases the amount of fuel during the period from timing t3 to timing t4. Injection pressure and injection rate begin to drop. At timing t4, in the fuel injection device 1, the lift amount of the first valve V1 becomes 0 [mm], the fuel injection pressure becomes 0 [MPa], and the fuel injection rate becomes 0 [mm ³ /s]. becomes. In the fuel injection device 1, no vibration is observed in the lift amount of the first valve V1, the fuel injection pressure, and the fuel injection rate during the period from timing t3 to timing t4. This is because, in the fuel injection device 1, the pressure in the first flow path F1 does not oscillate during the period.

After timing t4, the fuel injection device 1 controlled by the second control waits with the injection port H and the second flow path F2 closed until the next injection of fuel is started. Therefore, in the fuel injection device 1, the pressure in the first flow path F1 returns to the predetermined pressure Pb until the next injection of fuel is started. After timing t4, in the fuel injection device 1, the pressure in the first flow path F1 is such that the fuel flowing through the first flow path F1 toward the injection port H is dammed by the first valve V1 at time t4. Therefore, as indicated by the curve FX1, damped vibration occurs due to the occurrence of water hammer. However, in the fuel injection device 1, the influence of this damped oscillation is not transmitted to the combustion chamber CC because the injection port H is closed at the timing t4. Then, in the fuel injection device 1, this damped oscillation is settled within a period until the next injection of fuel is started.

Here, as described above, the fuel injection device 1 controlled by the first control starts injecting fuel into the combustion chamber CC from timing t3 at a pressure higher than the predetermined pressure Pb. It is impossible for the fuel injection device 1 controlled by the second control to start injecting fuel at a pressure higher than the predetermined pressure Pb, that is, at a pressure higher than the pressure of the high-pressure source 4 . In other words, it is impossible for a conventional fuel injection device to start injecting fuel at a pressure higher than the predetermined pressure Pb, that is, at a pressure higher than the pressure of the high-pressure source 4 . Then, as shown by graphs G2 to G4, as a result of starting to inject fuel at a pressure higher than the predetermined pressure Pb, the rise of curve FN2 is steeper and sharper than the rise of curve FX2. The rise of curve FN3 is steeper and sharper than the rise of curve FX3, and the rise of curve FN4 is steeper and sharper than the rise of curve FX4.

That is, in the fuel injection device 1, the rise of the lift amount of the first valve V1 is steeper and sharper than before, the rise of the fuel injection pressure is steeper and sharper than before, and the fuel is injected. This indicates that the rise in rate is steeper and sharper than in the past. In other words, in the fuel injection device 1, the injection port H can be opened faster than the conventional fuel injection device, and the injection pressure and the injection rate of the fuel can be increased faster than the conventional fuel injection device. Furthermore, it is possible to raise the injection pressure and the injection rate of the fuel more than the conventional fuel injection device. As a result, the fuel injection device 1 can further improve the fuel combustion efficiency as compared with the conventional fuel injection device. In addition, the fuel injection device 1 can realize a sharp rise of the fuel injection pressure from the timing t3 without using an expensive actuator with high response such as a piezo element. This indicates that the fuel injection device 1 can also suppress an increase in manufacturing costs. Naturally, the fuel injection device 1 can further sharpen the rising of the fuel injection pressure from the timing t3 by combining with the highly responsive actuator.

In addition, each of the above-mentioned first time and second time is set so that the combustion efficiency of the fuel approaches the desired combustion efficiency (for example, the highest combustion efficiency, etc.) by trial and error in advance tests, experiments, etc. Although it is determined, it may be determined based on theoretical calculation, may be determined by simulation, or may be determined by other methods.

In addition, ΔPmax, which is a change in the pressure that rises due to the water hammer action in the first flow path F1, the time required from timing t2 until the pressure in the first flow path F1 exceeds a predetermined pressure Pb, the first flow The length of time during which the pressure in the passage F1 continues to exceed the predetermined pressure Pb depends on the flow velocity, flow rate, etc. of the fuel flowing from the first passage F1 to the discharge port through the second passage F2. Determined. For this reason, the flow velocity, flow rate, etc. of the fuel flowing from the first flow path F1 to the discharge port through the second flow path F2 can be determined, for example, by trial and error in advance tests, experiments, etc., so that the combustion efficiency of the fuel reaches the desired combustion efficiency ( For example, the maximum combustion efficiency, etc.) may be determined based on theoretical calculations, simulations, or other methods.

<Modification 1 of Embodiment>
Modification 1 of the embodiment will be described below. In addition, in the modified example 1 of the embodiment, the same reference numerals are assigned to the same components as in the embodiment, and the description thereof is omitted. Hereinafter, for convenience of explanation, the fuel injection device 1 according to Modification 1 of the embodiment will be referred to as a fuel injection device 1A in order to distinguish it from the fuel injection device 1 according to the embodiment.

In the fuel injection device 1A, compared with the fuel injection device 1, the flow rate of the fuel is increased without changing the flow velocity of the fuel flowing from the first flow path F1 to the discharge port through the second flow path F2. . This can be achieved, for example, by increasing the diameter of the second flow path F2, forming the second flow path F2 in a tapered shape, and configuring the second flow path F2 with a plurality of pipe lines. Below, as an example, a case where the diameter of the second flow path F2 provided in the fuel injection device 1A is larger than the diameter of the second flow path F2 provided in the fuel injection device 1 will be described. In this case, the second valve V2 provided in the fuel injection device 1A also becomes larger than the second valve V2 provided in the fuel injection device 1 . As a result, in the fuel injection device 1A, the flow rate of the fuel dammed up by the second valve V2 increases at the timing t2, and the pressure in the first flow path F1 continues to exceed the predetermined pressure Pb due to the water hammer effect. becomes longer. As a result, the fuel injection device 1A can suppress damped oscillation of the pressure in the first flow path F1 during the period from the timing t3 to the timing t4.

FIG. 5 shows the opening/closing timing of each of the injection port H and the second flow path F2 in the fuel injection device 1A, the temporal change of the pressure in the first flow path F1, and the temporal change of the lift amount of the first valve V1. FIG. 3 is a diagram showing an example of each of a change in pressure, a change in fuel injection pressure over time, and a change in fuel injection rate over time.

The graph G1 shown in FIG. 5 is the same as the graph G1 shown in FIG. 4 except that the curve FN11 is plotted instead of the curve FN1. This is because the temporal change in the pressure in the first flow path F1 in the fuel injection device 1A controlled by the second control changes the pressure in the first flow path F1 in the fuel injection device 1 controlled by the second control. This is because it is the same as the temporal change of Below, the graph G1 shown in FIG. 5 is called the graph G11, and it demonstrates for convenience of explanation. Here, a curve FN11 shows another example of the temporal change in the pressure inside the first flow path F1 when the fuel injection device 1A is controlled by the first control.

Graph G2 shown in FIG. 5 is the same as graph G2 shown in FIG. 4 except that curve FN21 is plotted instead of curve FN2. This is because the temporal change in the lift amount of the first valve V1 in the fuel injection device 1A controlled by the second control changes the lift amount of the first valve V1 in the fuel injection device 1 controlled by the second control. This is because it is the same as a physical change. Below, the graph G2 shown in FIG. 5 is called the graph G21, and it demonstrates for convenience of explanation. Here, a curve FN21 shows another example of temporal change in the lift amount of the first valve V1 when the fuel injection device 1A is controlled by the first control.

Graph G3 shown in FIG. 5 is the same as graph G3 shown in FIG. 4 except that curve FN31 is plotted instead of curve FN3. This is because the temporal change in the fuel injection pressure in the fuel injection device 1A controlled by the second control is the same as the temporal change in the fuel injection pressure in the fuel injection device 1 controlled by the second control. is. For convenience of explanation, the graph G3 shown in FIG. 5 will be referred to as a graph G31 below. Here, a curve FN31 shows another example of temporal changes in the fuel injection pressure when the fuel injection device 1A is controlled by the first control.

Graph G4 shown in FIG. 5 is the same as graph G4 shown in FIG. 4 except that curve FN41 is plotted instead of curve FN4. This is because the temporal change in the fuel injection rate in the fuel injection device 1A controlled by the second control is the same as the temporal change in the fuel injection rate in the fuel injection device 1 controlled by the second control. is. Below, the graph G4 shown in FIG. 5 is called the graph G41, and it demonstrates for convenience of explanation. Here, a curve FN41 shows another example of temporal changes in the fuel injection rate when the fuel injection device 1A is controlled by the first control.

As indicated by the curve FN11, in the fuel injection device 1A, the pressure in the first flow path F1 only increases and then decreases during the period from timing t3 to timing t4, and does not vibrate. . The pressure in the first flow path F1 is higher than the predetermined pressure Pb over substantially the entire period. This is because the flow rate of fuel flowing through the second flow path F2 in the fuel injection device 1A is greater than the flow rate of fuel flowing through the second flow path F2 in the fuel injection device 1. This is because the length of time during which the pressure in the path F1 continues to exceed the predetermined pressure Pb is getting longer. As a result, as indicated by curves FN21, FN31, and FN41, in the fuel injection device 1A, the lift amount of the first valve V1, the fuel injection pressure, and the fuel injection rate all oscillate within the period. It disappears and only rises and then falls.

Further, as shown by the graph G11, the fuel injection device 1A controlled by the first control can also start injecting fuel into the combustion chamber CC from timing t3 at a pressure higher than the predetermined pressure Pb. . As each of the graphs G21 to G41 indicates, as a result of starting to inject fuel at a pressure higher than the predetermined pressure Pb, the rise of the curve FN21 is steeper and sharper than the rise of the curve FX2. The rise of curve FN31 is steeper and sharper than the rise of curve FX3, and the rise of curve FN41 is steeper and sharper than the rise of curve FX4.

That is, in the fuel injection device 1A as well, the rise of the lift amount of the first valve V1 is steeper and sharper than the conventional one, the rise of the fuel injection pressure is steeper and sharper than the conventional one, and the fuel is injected. This indicates that the rise in rate is steeper and sharper than in the past. In other words, even in the fuel injection device 1A, the injection port H can be opened faster than the conventional fuel injection device, and the fuel injection pressure and the injection rate can be increased faster than the conventional fuel injection device. Furthermore, it is possible to raise the injection pressure and the injection rate of the fuel more than the conventional fuel injection device. As a result, the fuel injection device 1A can further improve the fuel combustion efficiency as compared with the conventional fuel injection device, and in addition, the pressure fluctuation in the first flow path F1 caused by the water hammer action can be reduced. It is possible to suppress the influence from being transmitted to the inside of the combustion chamber CC.

As described above, the fuel injection device 1 and the fuel injection device 1A are fuel injection devices that inject fuel into the combustion chamber CC of the internal combustion engine EG, and have injection ports H that inject fuel into the combustion chamber CC. , a high-pressure source 4 that supplies fuel at a predetermined pressure Pb and an injection port H are connected, and a first flow path F1 to which fuel is supplied from the high-pressure source 4, and the injection port is provided in the first flow path F1. a first valve V1 that opens and closes H; a second flow path F2 that is connected to the first flow path F1 and to which fuel is supplied from the first flow path F1; a second valve V2 for opening and closing the path F2. As a result, the fuel injection device 1 and the fuel injection device 1A open the injection port H by the first valve V1 within a period when the pressure in the first flow path F1 is higher than the predetermined pressure Pb, Fuel can be injected into the combustion chamber CC at a pressure higher than the pressure Pb of . As a result, the fuel injection device 1 and the fuel injection device 1A can further improve the fuel combustion efficiency.

<Modification 2 of Embodiment>
Modification 2 of the embodiment will be described below. In addition, in the modified example 2 of the embodiment, the same reference numerals are given to the same components as in the embodiment, and the description thereof is omitted. Hereinafter, for convenience of explanation, the fuel injection device 1 according to Modification 1 of the embodiment is distinguished from the fuel injection device 1 according to the embodiment and the fuel injection device 1A according to Modification 1 of the embodiment. This will be described as an injection device 1B.

In Modified Example 2 of the embodiment, as shown in FIG. 6, the fuel injector 2 includes a first flow path F1, an injection port H, a first valve V1, a drive portion A1, and a second flow path F2. , a second valve V2 and an actuator A2, as well as a third valve V3 and an actuator A3. FIG. 6 is a diagram showing another example of the configuration of the fuel injection device 1B. Further, in Modification 2 of the embodiment, as shown in FIG. A third valve drive circuit 35 is provided. FIG. 7 is a diagram showing another example of the functional configuration of the ECU 3. As shown in FIG. In FIG. 6, the configuration of the fuel injector 2 is realized by connecting two fuel injectors in series. However, instead of connecting two fuel injectors in series, the configuration of the fuel injectors 2 may also be realized in other ways.

The third valve V3 is provided in the first flow path F1, and is a portion of the first flow path F1 located upstream of the first valve V1 in the first flow path F1. Among the portions of the flow path F1, it is provided in the portion PP2 located downstream of the connecting portion PP1 between the first flow path F1 and the second flow path F2 in the first flow path F1. That is, the third valve V3 opens and closes the first flow path F1 in the portion PP2. Therefore, when the first valve V1 closes the injection port H and the third valve V3 closes the first flow path F1, fuel is retained in the first flow path F1. A space S is formed. Therefore, hereinafter, for convenience of explanation, the first valve V1 closes the injection port H and the third valve V3 closes the first flow path F1 in the space in the first flow path F1. A space closed by the first valve V1 and the third valve V3 in the case of the state is referred to as a space S for explanation. In the space S, when the first valve V1 closes the injection port H and the third valve V3 opens the first flow path F1, Fuel is supplied and accumulated through Therefore, the pressure in the space S is maintained when the first valve V1 closes the injection port H and the third valve V3 closes the first flow path F1. Therefore, the space S can also be interpreted as a pressure accumulator that accumulates pressure.

In the example shown in FIG. 6, the third valve V3 is the nozzle needle. The third valve V3 may be any member instead of the nozzle needle as long as it is a member capable of opening and closing the portion PP2.

The third valve V3 closes the first flow path F1 by blocking the portion PP2. More specifically, the third valve V3 does not move while blocking the portion PP2 when the ECU 3 does not drive the drive portion A3. This causes the third valve V3 to keep the first flow path F1 closed in that case. On the other hand, the third valve V3 moves in the direction to open the portion PP2 when the ECU 3 drives the driving portion A3. As a result, the third valve V3 opens the first flow path F1 in that case.

The driving section A3 causes the third valve V3 to open and close the portion PP2. The driving section A3 has, for example, a solenoid, a piezo element, etc. as an actuator for driving the third valve V3. When the drive unit A3 is not driven by the ECU 3, the pressure of the fuel supplied through the pipe line connected to the first flow path F1 (that is, the predetermined pressure Pb) causes the third valve V3 to move to the portion PP2. to continue to block part PP2. That is, the driving part A3 continues to close the first flow path F1 by the third valve V3 in this case. Here, the pipeline connects the first flow path F1 and an outlet through which the fuel passing through the pipeline is discharged. This outlet is connected, for example, to a fuel tank (this fuel tank may or may not be connected to the high pressure source 4) via a conduit (not shown). Therefore, the fuel flowing out from this outlet eventually returns to the fuel tank. It should be noted that the configuration beyond this discharge port may be replaced with any other configuration. Therefore, further detailed description of the configuration beyond this discharge port will be omitted. On the other hand, when driven by the ECU 3, the driving portion A3 reduces the pressure of the fuel supplied through the pipe (that is, the predetermined pressure Pb) by opening a valve provided in the driving portion A3. , the third valve V3 in the direction of opening the part PP2. That is, in this case, the driving part A3 opens the first flow path F1 by means of the third valve V3. The structure and operation for opening and closing the third valve V3 may be a known structure and operation, or may be a structure and operation that will be developed in the future, so further detailed description will be omitted.

The third valve drive circuit 35 supplies a drive current for driving the drive section A3 that opens and closes the third valve V3 to the drive section A3. Here, the control unit 36 controls the third valve driving circuit 35 and causes the driving unit A3 to open and close the first flow path F1 by the third valve V3 according to the timing stored in the storage unit 32 in advance.

<Control Method of Fuel Injector>
A specific example of the control method for the fuel injection device 1B will be described below with reference to FIG. In the following, as an example, when the driving current C1 is supplied to the driving part A1, the driving part A1 opens the injection port H by the first valve V1, and when the driving current C2 is supplied to the driving part A2, the driving is performed. A case will be described where, when the part A2 opens the second flow path F2 by the second valve V2 and the driving current C3 is supplied to the driving part A3, the driving part A3 opens the first flow path F1 by the third valve V3. That is, the driving portion A1 closes the injection port H by the first valve V1 when the supply of the driving current C1 to the driving portion A1 is stopped. Further, when the supply of the driving current C2 to the driving portion A2 is stopped, the driving portion A2 closes the second flow path F2 by the second valve V2. Further, when the supply of the driving current C3 to the driving portion A3 is stopped, the driving portion A3 closes the first flow path F1 by the third valve V3. Moreover, below, the control method of the fuel-injection apparatus 1B in the case of performing main injection is demonstrated as an example. However, this control method may be applied to other injections such as pre-injection and pilot injection. Further, hereinafter, among the controls of the fuel injection device 1B, the control involving the opening and closing of the injection port H, the opening and closing of the first flow path F1, and the opening and closing of the second flow path F2 will be referred to as the third control as an example. explain. Further, hereinafter, of the control of the fuel injection device 1B, the control involving the opening and closing of the injection port H and the opening and closing of the first flow path F1 and not involving the opening and closing of the second flow path F2 will be described as an example. 4 control will be described. When the fourth control is performed, temporal changes in the injection pressure and injection rate of the fuel in the fuel injection device 1B do not include a valve corresponding to the second valve V2, and the first valve V1 and the third valve V3 corresponding to a conventional fuel injector (e.g., a fuel injector known as a TAIZAC (in-line two-valve instantaneous changeover injector)), fuel injection pressure and injection rate, respectively, over time. Almost no change. For this reason, comparing the control method of the fuel injection device 1B by the third control and the control method of the fuel injection device 1B by the fourth control can be compared with a fuel injection device (for example, TAIZAC) different from the fuel injection device 1B. This leads to a clear demonstration of the superiority of the fuel injection device 1B. Therefore, in the following, the control method of the fuel injection device 1B by the third control and the control method of the fuel injection device 1B by the fourth control are compared, and the points that the fuel injection device 1B is superior to the conventional fuel injection device. will be explained.

FIG. 8 shows the opening/closing timing of each of the injection port H, the first flow path F1, and the second flow path F2 in the fuel injection device 1B, the temporal change in the pressure in the first flow path F1, and the pressure in the space S. FIG. 5 is a diagram showing an example of temporal changes in pressure, temporal changes in the lift amount of the first valve V1, temporal changes in fuel injection pressure, and temporal changes in fuel injection rate; is.

The horizontal axis of each of the graphs G1A to G5A shown in FIG. 8 indicates the elapsed time in the period during which the fuel injection device 1 performs the main injection. However, in the example shown in FIG. 8, the timing at which the injection port H of the fuel injection device 1B controlled by the third control begins to open and the timing at which the injection port H of the fuel injection device 1B controlled by the fourth control begins to open. timing. Further, in this example, the timing at which the injection port H is closed in the fuel injection device 1B controlled by the third control is matched with the timing at which the injection port H is closed in the fuel injection device 1B controlled by the fourth control. ing. By matching these timings, FIG. 8 clearly shows the difference between the fuel injection device 1B controlled by the third control and the fuel injection device 1B controlled by the fourth control.

The vertical axis of the graph G1A shown in FIG. 8 indicates the pressure inside the first flow path F1. A curve FN1A plotted on the graph G1A shows an example of temporal change in pressure in the first flow path F1 when the fuel injection device 1B is controlled by the third control. On the other hand, a curve FX1A plotted on the graph G1A shows an example of temporal change in the pressure inside the first flow path F1 when the fuel injection device 1B is controlled by the fourth control. Also, a timing chart TC1A showing opening/closing timing of the first flow path F1 and a timing chart TC2A showing opening/closing timing of the second flow path F2 are superimposed on the graph G1A.

The vertical axis of the graph G2A shown in FIG. 8 indicates the pressure in the space S. A curve FN2A plotted on the graph G2A shows an example of temporal changes in the pressure in the space S when the fuel injection device 1B is controlled by the third control. On the other hand, a curve FX2A plotted on the graph G2A shows an example of temporal change in pressure in the space S when the fuel injection device 1B is controlled by the fourth control.

The vertical axis of the graph G3A shown in FIG. 8 indicates the lift amount of the first valve V1. A curve FN3A plotted on the graph G3A shows an example of temporal changes in the lift amount of the first valve V1 when the fuel injection device 1B is controlled by the third control. On the other hand, a curve FX3A plotted on the graph G3A shows an example of temporal changes in the lift amount of the first valve V1 when the fuel injection device 1B is controlled by the fourth control. A timing chart TC3A showing the opening/closing timing of the injection port H is superimposed on the graph G3A.

The vertical axis of graph G4A shown in FIG. 8 indicates the fuel injection pressure. A curve FN4A plotted on the graph G4A shows an example of temporal changes in the fuel injection pressure when the fuel injection device 1B is controlled by the third control. On the other hand, a curve FX4A plotted on the graph G4A shows an example of temporal changes in the fuel injection pressure when the fuel injection device 1B is controlled by the fourth control.

The vertical axis of graph G5A shown in FIG. 8 indicates the fuel injection rate. A curve FN5A plotted on the graph G5A shows an example of temporal changes in the fuel injection rate when the fuel injection device 1B is controlled by the third control. On the other hand, a curve FX5A plotted on the graph G5A shows an example of temporal changes in the fuel injection rate when the fuel injection device 1B is controlled by the fourth control.

In the example shown in FIG. 8, the fuel injection device 1B controlled by the third control waits with the injection port H, the first flow path F1, and the second flow path F2 closed until timing t5. At this time, the pressure in the space S is maintained at a predetermined pressure P0 until timing t5. The predetermined pressure P0 may be any pressure that is higher than 0 [MPa] and lower than the predetermined pressure Pb. Then, the fuel injection device 1B starts to open the second flow path F2 at timing t5. As a result, as indicated by the curve FN1A, in the fuel injection device 1B, the pressure inside the first flow path F1 begins to decrease at timing t5. This is because the fuel starts to flow from the first flow path F1 to the second flow path F2 at timing t5.

After that, in the fuel injection device 1B controlled by the third control, the driving section A2 starts moving the second valve V2 so that the second flow path F2 is closed at timing t6 after a predetermined third time has elapsed from timing t5. . As a result, in the fuel injection device 1, the pressure inside the first flow path F1 starts to rise at timing t6.

Then, in the fuel injection device 1B controlled by the third control, the pressure in the first flow path F1 momentarily becomes higher than the predetermined pressure Pb at the timing after the timing t6. This is because the fuel flowing from the first flow path F1 through the second flow path F2 to the discharge port is dammed by the second valve V2, and the resulting water hammer action causes the fuel to flow into the first flow path F1. This phenomenon occurs because the pressure momentarily becomes higher than the predetermined pressure Pb.

However, as indicated by the curve FN1A, the pressure in the first flow path F1 damps and oscillates after timing t6. Therefore, the fuel injection device 1B controlled by the third control starts opening the first flow path F1 at timing t7. At timing t7, among the timings after timing t6, the pressure in the first flow path F1 rises from the pressure less than the predetermined pressure Pb to the pressure exceeding the predetermined pressure Pb, and then the pressure in the first flow path F1 Any timing may be used as long as it is within the period until starts falling again. Here, also in FIG. 8, ΔPmax indicates the difference between the highest pressure due to the water hammer action and the predetermined pressure Pb among the pressures in the first flow path F1. That is, the fuel injection device 1B sets the timing within the period until the pressure in the first flow path F1 reaches (Pb+ΔPmax) among the timings after the timing t6 as the timing t7, and the first flow injection is performed at the timing t7. Begin to open road F1.

The time difference between the timing t6 and the timing t7 is determined, for example, by trial and error in advance tests, experiments, etc., so that the combustion efficiency of the fuel approaches the desired combustion efficiency (for example, the highest combustion efficiency, etc.). , may be determined based on theoretical calculation, may be determined by simulation, or may be determined by other methods. Since the first flow path F1 begins to open at the timing t7 thus determined, the fuel in the first flow path F1 begins to be supplied into the space S from the first flow path F1 at the timing t7. Therefore, the pressure in space S also begins to rise at timing t7, as indicated by curve FN2A. Here, the pressure in the first flow path F1 exceeds the predetermined pressure Pb due to the water hammer effect described above after timing t7. Therefore, after timing t7, the fuel in the first flow path F1 is supplied from the first flow path F1 into the space S at a pressure higher than the predetermined pressure Pb. The timing t7 may be adjusted so that the fuel in the first flow path F1 is supplied into the space S at a pressure higher than the predetermined pressure Pb at the timing t7.

Here, as described above, the pressure in the space S is maintained by closing both the injection port H and the first flow path F1. Therefore, after timing t7, when both the injection port H and the first flow path F1 are closed while the pressure in the space S is higher than the predetermined pressure Pb, the pressure in the space S is , is maintained at a pressure higher than the predetermined pressure Pb.

After timing t7, in the fuel injection device 1B controlled by the third control, the driving portion A3 closes the third valve V3 so that the first flow path F1 is closed at timing t9 when a predetermined fourth time has elapsed from timing t7. start moving.

Further, after timing t7, in the fuel injection device 1B controlled by the third control, the driving portion A1 causes the first valve V1 to open so that the injection port H is opened at timing t8 after the lapse of a predetermined fifth time from timing t7. start moving. Note that the timing t8 may be the timing before the timing t9, the timing after the timing t9, or the same timing as the timing t9 as long as the timing t8 is after the timing t7. may In the example shown in FIG. 8, timing t8 is earlier than timing t9. Since the fuel injection device 1B opens the injection port H at the timing t8, the fuel can be injected from the injection port H into the combustion chamber CC at a pressure higher than the predetermined pressure Pb. In this example, at timing t8, the fuel injection device 1B can inject fuel from the injection port H into the combustion chamber CC at a pressure of (Pb+ΔPmax).

After timing t8, in the fuel injection device 1B controlled by the third control, the drive unit A1 moves the first valve V1 so that the injection port H closes at timing t10 when a predetermined sixth time has elapsed from timing t8. start. Triggered by the drive unit A1 starting to move the first valve V1, the fuel injection device 1B reduces the lift amount of the first valve V1 and increases the amount of fuel during the period from timing t8 to timing t10. Injection pressure and injection rate begin to drop. Then, at timing t10, in the fuel injection device 1B, the lift amount of the first valve V1 becomes 0 [mm], the fuel injection pressure becomes 0 [MPa], and the fuel injection rate becomes 0 [mm ³ /s]. becomes. In the period from timing t8 to timing t10, no vibration is observed in the lift amount of the first valve V1, the fuel injection pressure, and the fuel injection rate. This is because the first flow path F1 is closed by the third valve V3 at the timing t9, so that the influence of the damped oscillation of the pressure in the first flow path F1 after the timing t9 is not transmitted to the space S. . Further, during the period from timing t9 to timing t10, the fuel in the space S decreases with the lapse of time because the fuel is not supplied from the high pressure source 4 to the space S through the first flow path F1. As a result, the pressure in the space S also decreases as the timing t9 approaches the timing t10. In the example shown in FIG. 8, at timing t10, the pressure in the space S is the predetermined pressure P0. As described above, the pressure in the space S decreases during the period from the timing t9 to the timing t10, so that the fuel injection device 1B realizes reverse delta injection as indicated by the curves FN4A and FN5A. be done. As a result, the fuel injection device 1B can suppress the occurrence of an excessively rich air-fuel mixture mass, etc., and improve the fuel combustion efficiency more reliably.

After timing t10, the fuel injection device 1B controlled by the third control waits with the injection port H, the first flow path F1, and the second flow path F2 closed until the next injection of fuel is started. do. Therefore, in the fuel injection device 1B, the pressure in the first flow path F1 returns to the predetermined pressure Pb until the next injection of fuel is started. Further, in the fuel injection device 1B, the pressure in the space S is maintained at the predetermined pressure P0 until the next injection of fuel is started.

On the other hand, in the example shown in FIG. 8, as shown in the timing chart TC1A, the fuel injection device 1B controlled by the fourth control keeps the injection port H, the first flow passage F1, the second flow It waits with the road F2 closed. Then, the fuel injection device 1 starts to open the first flow path F1 at timing t7. Since the first flow path F1 begins to open, the fuel in the first flow path F1 is supplied from the first flow path F1 into the space S at the predetermined pressure Pb at timing t7. Therefore, the pressure in space S also begins to rise at timing t7, as indicated by curve FX2A.

Here, after timing t7, in a state in which both the injection port H and the first flow path F1 are closed in a state where the pressure in the space S is the predetermined pressure Pb, the pressure in the space S is kept at a predetermined pressure Pb. is maintained at the pressure Pb of .

After timing t7, in the fuel injection device 1B controlled by the fourth control, the driving section A3 starts moving the third valve V3 so as to close the first flow path F1 at timing t9.

After timing t7, in the fuel injection device 1B controlled by the fourth control, the drive unit A1 starts moving the first valve V1 so that the injection port H opens at timing t8. Since the fuel injection device 1B opens the injection port H at the timing t8, the fuel is injected from the injection port H into the combustion chamber CC at a predetermined pressure Pb.

After timing t8, in the fuel injection device 1B controlled by the fourth control, the driving section A1 starts moving the first valve V1 so that the injection port H is closed at timing t10. Triggered by the drive unit A1 starting to move the first valve V1, the fuel injection device 1B reduces the lift amount of the first valve V1 and increases the amount of fuel during the period from timing t8 to timing t10. Injection pressure and injection rate begin to drop. Then, at timing t10, in the fuel injection device 1B, the lift amount of the first valve V1 becomes 0 [mm], the fuel injection pressure becomes 0 [MPa], and the fuel injection rate becomes 0 [mm ³ /s]. becomes. During the period from timing t9 to timing t10, the amount of fuel in the space S decreases with the lapse of time because fuel is not supplied from the high pressure source 4 to the space S through the first flow path F1. As a result, the pressure in the space S also decreases as the timing t9 approaches the timing t10. In the example shown in FIG. 8, at timing t10, the pressure in the space S is the predetermined pressure P0. As described above, the pressure in the space S decreases during the period from the timing t9 to the timing t10, so that the fuel injection device 1B also realizes reverse delta injection as indicated by the curves FN4A and FN5A. It is

After timing t10, the fuel injection device 1B controlled by the fourth control waits with the injection port H, the first flow path F1, and the second flow path F2 closed until the next injection of fuel is started. do. Therefore, in the fuel injection device 1B, the pressure in the first flow path F1 returns to the predetermined pressure Pb until the next injection of fuel is started. Further, in the fuel injection device 1B, the pressure in the space S is maintained at the predetermined pressure P0 until the next injection of fuel is started.

Here, as described above, the fuel injection device 1 controlled by the third control starts injecting fuel into the combustion chamber CC from timing t8 at a pressure higher than the predetermined pressure Pb. It is impossible for the fuel injection device 1 controlled by the fourth control to start injecting fuel at a pressure higher than the predetermined pressure Pb, that is, at a pressure higher than the pressure of the high-pressure source 4 . In other words, it is impossible for the conventional fuel injection device to start injecting fuel at a pressure higher than the predetermined pressure Pb, that is, at a pressure higher than the pressure of the high-pressure source 4 . As each of the graphs G2A to G5A shows, as a result of starting to inject fuel at a pressure higher than the predetermined pressure Pb, the rise of the curve FN2A is steeper and sharper than the rise of the curve FX2A. The rise of curve FN3A is steeper and sharper than the rise of curve FX3A, the rise of curve FN4A is steeper and sharper than the rise of curve FX4A, and the rise of curve FN5A is steeper than the rise of curve FX5A. are becoming sharper and sharper.

That is, in the fuel injection device 1B, even when control is performed with the opening and closing of the third valve V3, the rise of the lift amount of the first valve V1 becomes steeper and sharper than in the conventional art, and the fuel is injected. It shows that the rise of the injection pressure is steeper and sharper than before, and the rise of the fuel injection rate is steeper and sharper than before. In other words, in the fuel injection device 1B, the injection port H can be opened faster than the conventional fuel injection device, and the injection pressure and injection rate of the fuel can be increased faster than the conventional fuel injection device. Furthermore, it is possible to raise the injection pressure and the injection rate of the fuel more than the conventional fuel injection device. As a result, the fuel injection device 1B can further improve the fuel combustion efficiency as compared with the conventional fuel injection device. Further, the fuel injection device 1B can realize a sharp rise of the fuel injection pressure from the timing t8 without using an expensive actuator with high response such as a piezo element. This indicates that the fuel injection device 1 can also suppress an increase in manufacturing costs. Naturally, the fuel injection device 1B can further sharpen the rising of the fuel injection pressure from the timing t8 by combining with the highly responsive actuator.

In addition, each of the above-mentioned 3rd time to 6th time is set so that the combustion efficiency of the fuel approaches the desired combustion efficiency (for example, the highest combustion efficiency, etc.) by trial and error in advance tests, experiments, etc. Although it is determined, it may be determined based on theoretical calculation, may be determined by simulation, or may be determined by other methods. However, the magnitude of the predetermined pressure P0 is determined according to the length of the sixth time. The longer the sixth time, the lower the predetermined pressure P0. On the other hand, the shorter the sixth time, the higher the predetermined pressure P0.

<Modification 3 of Embodiment>
Modification 3 of the embodiment will be described below. Modification 3 of the embodiment is a modification of Modification 2 of the embodiment. In addition, in Modification 3 of the embodiment, the same reference numerals are given to the same components as in Modification 2 of the embodiment, and the description thereof is omitted. Hereinafter, for convenience of explanation, the fuel injection device 1B according to Modification 3 of the embodiment will be referred to as fuel injection device 1C in order to distinguish it from the fuel injection device 1B according to Modification 2 of the embodiment.

Compared with the fuel injection device 1B, the fuel injection device 1C increases the flow rate of the fuel without changing the flow velocity of the fuel flowing from the first flow path F1 to the discharge port through the second flow path F2. . Below, as an example, a case where the diameter of the second flow path F2 provided in the fuel injection device 1C is larger than the diameter of the second flow path F2 provided in the fuel injection device 1B will be described. In this case, the second valve V2 provided in the fuel injection device 1C also becomes larger than the second valve V2 provided in the fuel injection device 1B. As a result, in the fuel injection device 1C, the flow rate of the fuel dammed up by the second valve V2 increases at timing t6, and the length of time during which the pressure in the first flow path F1 continues to exceed the predetermined pressure Pb due to the water hammer action. becomes longer.

FIG. 9 shows the opening and closing timings of the injection port H, the first flow path F1, and the second flow path F2 in the fuel injection device 1C, the temporal change in the pressure in the first flow path F1, and the pressure in the space S. FIG. 5 is a diagram showing an example of temporal changes in pressure, temporal changes in the lift amount of the first valve V1, temporal changes in fuel injection pressure, and temporal changes in fuel injection rate; is.

The graph G1A shown in FIG. 9 is the same graph as the graph G1A shown in FIG. 8 except that the curve FN11A is plotted instead of the curve FN1A. This is because the temporal change in the pressure in the first flow path F1 in the fuel injection device 1C controlled by the fourth control changes the pressure in the first flow path F1 in the fuel injection device 1B controlled by the fourth control. This is because it is the same as the temporal change of Below, for convenience of explanation, the graph G1A shown in FIG. 9 will be referred to as a graph G11A. Here, the curve FN11A shows another example of the temporal change in the pressure inside the first flow path F1 when the fuel injection device 1C is controlled by the third control.

The graph G2A shown in FIG. 9 is the same graph as the graph G2A shown in FIG. 8 except that the curve FN21A is plotted instead of the curve FN2A. This is because the temporal change in the pressure in the space S in the fuel injection device 1C controlled by the fourth control is the same as the temporal change in the pressure in the space S in the fuel injection device 1B controlled by the fourth control. because they are the same. Below, for convenience of explanation, the graph G2A shown in FIG. 9 will be referred to as a graph G21A. Here, curve FN21A shows another example of temporal change in pressure in space S when fuel injection device 1C is controlled by the third control.

The graph G3A shown in FIG. 9 is the same graph as the graph G3A shown in FIG. 8 except that the curve FN31A is plotted instead of the curve FN3A. This is because the temporal change in the lift amount of the first valve V1 in the fuel injection device 1C controlled by the fourth control is the same as the lift amount of the first valve V1 in the fuel injection device 1B controlled by the fourth control. This is because it is the same as a physical change. Below, for convenience of explanation, the graph G3A shown in FIG. 9 will be referred to as a graph G31A. Here, a curve FN31A shows another example of temporal change in the lift amount of the first valve V1 when the fuel injection device 1C is controlled by the third control.

Graph G4A shown in FIG. 9 is the same graph as graph G4A shown in FIG. 8 except that curve FN41A is plotted instead of curve FN4A. This is because the temporal change in the fuel injection pressure in the fuel injection device 1C controlled by the fourth control is the same as the temporal change in the fuel injection pressure in the fuel injection device 1B controlled by the fourth control. is. Below, for convenience of explanation, the graph G4A shown in FIG. 9 will be referred to as a graph G41A. Here, the curve FN41A shows another example of temporal changes in the fuel injection pressure when the fuel injection device 1C is controlled by the third control.

The graph G5A shown in FIG. 9 is the same graph as the graph G5A shown in FIG. 8 except that the curve FN51A is plotted instead of the curve FN5A. This is because the temporal change in the fuel injection rate in the fuel injection device 1C controlled by the fourth control is the same as the temporal change in the fuel injection rate in the fuel injection device 1B controlled by the fourth control. is. Below, for convenience of explanation, the graph G5A shown in FIG. 9 will be referred to as a graph G51A. Here, the curve FN51A shows another example of temporal changes in the fuel injection rate when the fuel injection device 1C is controlled by the third control.

As indicated by the curve FN11A, in the fuel injection device 1C, the pressure in the first flow path F1 only increases and then decreases during the period from timing t8 to timing t10, and does not vibrate. . The pressure in the first flow path F1 is higher than the predetermined pressure Pb over substantially the entire period. In the fuel injection device 1C, when the first flow path F1 is closed, the pressure inside the first flow path F1 does not affect the space S and the combustion chamber CC. Therefore, how the pressure in the space S in the fuel injection device 1C, the lift amount of the first valve V1, the injection pressure of the fuel, and the injection rate of the fuel change with time varies depending on the pressure in the space S in the fuel injection device 1B. This is the same as how the pressure, the lift amount of the first valve V1, the fuel injection pressure, and the fuel injection rate change over time. However, in the fuel injection device 1C, by adjusting the flow rate, flow rate, etc. of the fuel flowing through the second flow path F2, the pressure in the first flow path F1 can be instantaneously increased (instantaneous to the extent that pressure resistance is not affected). The range of increase can be further increased. As a result, the fuel injection device 1C can inject a large amount of fuel without smoke, and can increase the torque and output of the internal combustion engine EG. For example, when the fuel injection device 1C is applied to an automobile engine, it is possible to generate a large amount of torque without smoke by ultra-high pressure injection during an acceleration phase during overtaking. Further, for example, when the fuel injection device 1C is applied to an engine for power generation, it is possible to inject a large amount of fuel without smoke when the demand for electric power surges, thereby suppressing a decrease in the rotation speed of the engine for power generation. can. It should be noted that such an instantaneous rise width of the pressure in the first flow path F1 increases as the diameter of the second flow path F2 provided in the fuel injection device 1C increases, as shown in this example. can be done. That is, in the fuel injection device 1C, the diameter of the second flow path F2 is larger than that of the fuel injection device 1B. The instantaneous rise width of the internal pressure can be made even larger than that of the fuel injection device 1B.

Further, as shown by the graphs G21A to G51A, the fuel injection device 1C controlled by the third control also starts injecting fuel into the combustion chamber CC from timing t8 at a pressure higher than the predetermined pressure Pb. be able to. As shown by graphs G41A and G51A, as a result of starting to inject fuel at a pressure higher than the predetermined pressure Pb, the rise of curve FN31A is steeper and sharper than the rise of curve FX3A. The rise of curve FN41A is steeper and sharper than the rise of curve FX4A, and the rise of curve FN51A is steeper and sharper than the rise of curve FX5A.

That is, in the fuel injection device 1C as well, the rise of the lift amount of the first valve V1 is steeper and sharper than the conventional one, the rise of the fuel injection pressure is steeper and sharper than the conventional one, and the fuel is injected. This indicates that the rise in rate is steeper and sharper than in the past. In other words, even with the fuel injection device 1C, the injection port H can be opened faster than the conventional fuel injection device, and the fuel injection pressure and injection rate can be increased faster than the conventional fuel injection device. Furthermore, it is possible to raise the injection pressure and the injection rate of the fuel more than the conventional fuel injection device. As a result, the fuel injection device 1C can further improve the fuel combustion efficiency as compared with the conventional fuel injection device, and in addition, the pressure fluctuation in the first flow path F1 caused by the water hammer action can be reduced. It is possible to suppress the influence from being transmitted to the inside of the combustion chamber CC.

As described above, the fuel injection device 1B and the fuel injection device 1C are fuel injection devices that inject fuel into the combustion chamber CC of the internal combustion engine EG, and have injection ports H that inject fuel into the combustion chamber CC. , a high-pressure source 4 that supplies fuel at a predetermined pressure Pb and an injection port H are connected, and a first flow path F1 to which fuel is supplied from the high-pressure source 4, and the injection port is provided in the first flow path F1. a first valve V1 that opens and closes H; a second flow path F2 that is connected to the first flow path F1 and to which fuel is supplied from the first flow path F1; A second valve V2 that opens and closes the passage F2, and a portion that is provided in the first passage F1 and located upstream of the first valve V1 in the first passage F1 among the portions of the first passage F1. and a third valve that opens and closes a portion of the first flow path F1 located downstream of the connecting portion between the first flow path F1 and the second flow path F2 in the first flow path F1. V3, and in the first flow path F1, when the first valve V1 closes the injection port H and the third valve V3 closes the first flow path F1, fuel is formed. As a result, the fuel injection device 1B and the fuel injection device 1C open the injection port H by the first valve V1 within a period in which the pressure in the first flow path F1 is higher than the predetermined pressure Pb. Fuel can be injected into the combustion chamber CC at a pressure higher than the pressure Pb of . As a result, the fuel injection device 1B and the fuel injection device 1C can further improve the fuel combustion efficiency.

<Modification 4 of Embodiment>
Modification 4 of the embodiment will be described below. In addition, in the modification 4 of the embodiment, the same reference numerals are assigned to the same components as in the embodiment, and the description thereof is omitted. In the following, as an example, a case where the internal combustion engine EG is provided with a plurality of different combustion chambers CC2 instead of the combustion chambers CC will be described.

FIG. 10 is a diagram showing an example of the configuration of the fuel injection system 10. As shown in FIG. The fuel injection system 10 includes multiple fuel injectors. Each of these multiple fuel injection devices injects fuel into one of the multiple combustion chambers CC2. These multiple fuel injection devices include some or all of fuel injection device 1, fuel injection device 1A, fuel injection device 1B, and fuel injection device 1C. Below, as an example, a case where the fuel injection system 10 includes four fuel injection devices will be described. In this case, the internal combustion engine EG comprises four combustion chambers CC2. Each of these four fuel injection devices may be fuel injection device 1, fuel injection device 1A, fuel injection device 1B, or fuel injection device 1C. For this reason, in FIG. 10, four fuel injection devices 1 are labeled "1, 1A, 1B, 1C". Some of these four fuel injection devices may be fuel injection devices different from all of fuel injection device 1, fuel injection device 1A, fuel injection device 1B, and fuel injection device 1C.

For convenience of explanation, the four combustion chambers CC2 are hereinafter referred to as combustion chambers CC2-1 to CC2-4. Further, in the following, for convenience of explanation, the four fuel injection devices included in the fuel injection system 10 will be referred to as a first fuel injection device 1D1 to a fourth fuel injection device 1D4. The first fuel injection device 1D1 is one of the fuel injection device 1, the fuel injection device 1A, the fuel injection device 1B, and the fuel injection device 1C, and is a fuel injection device that injects fuel into the combustion chamber CC2-1. be. The second fuel injection device 1D2 is one of the fuel injection device 1, the fuel injection device 1A, the fuel injection device 1B, and the fuel injection device 1C, and is a fuel injection device that injects fuel into the combustion chamber CC2-2. be. The third fuel injection device 1D3 is one of the fuel injection device 1, the fuel injection device 1A, the fuel injection device 1B, and the fuel injection device 1C, and is a fuel injection device that injects fuel into the combustion chamber CC2-3. be. The fourth fuel injection device 1D4 is one of the fuel injection device 1, the fuel injection device 1A, the fuel injection device 1B, and the fuel injection device 1C, and is a fuel injection device that injects fuel into the combustion chamber CC2-4. be. Further, in the following, for convenience of explanation, the fuel injection device 1D will be referred to as the first fuel injection device 1D1, the second fuel injection device 1D2, the third fuel injection device 1D3, and the fourth fuel injection device 1D4 unless it is necessary to distinguish between them. will be described.

In the fuel injection system 10, the first flow paths F1 of the four fuel injection devices 1D are connected to the 0th flow path F0 connected to the high pressure source 4. In the example shown in FIG. 10, each of the first flow paths F1 of the four fuel injection devices 1D is connected to the 0th flow path F0 at one point. However, some or all of the first flow paths F1 of the four fuel injection devices 1D may be connected to the 0th flow paths F0 at different portions.

Also, in the fuel injection system 10, the second flow path F2 is not connected to each of the first flow paths F1 of the four fuel injection devices 1D, but is connected to the 0th flow path F0. That is, in the fuel injection system 10, one second flow path F2 is shared by each of the four fuel injection devices 1D. In the example shown in FIG. 10, the second flow path F2 is connected to the portion PP3. good.

Also in the fuel injection system 10, the second flow path F2 is provided with the second valve V2. Also in the fuel injection system 10, the second valve V2 is driven by the driving portion A2.

Thus, the fuel injection system 10 is connected to four fuel injection devices 1D for injecting fuel into the combustion chamber CC2 of the internal combustion engine EG, and a high pressure source 4 for supplying fuel at a predetermined pressure Pb. a 0th flow path F0 to which fuel is supplied from, a second flow path F2 connected to the 0th flow path F0 and to which fuel is supplied from the 0th flow path F0; and a second valve V2 for opening and closing the second flow path F2.

As a result, the fuel injection system 10 instantaneously raises the pressure in the first flow path F1 to a pressure higher than the predetermined pressure Pb by the water hammer effect generated by closing the 0th flow path F0 by the second valve V2. can be raised to Therefore, the fuel injection system 10 can operate each of the four fuel injection devices 1D provided in the fuel injection system 10 as described in each of the embodiment and Modifications 1 to 3 of the embodiment. As a result, the fuel injection system 10, by opening and closing the 0th flow path F0 by the second valve V2, from each of the four fuel injection devices 1D into each of the four combustion chambers CC2, the pressure higher than the pressure of the high pressure source 4 Fuel can be injected at high pressure. This is desirable because it leads to improvement in fuel combustion efficiency of the internal combustion engine EG while reducing the number of parts of the internal combustion engine EG.

Here, FIG. 11 shows the opening/closing timing of the second flow path F2, the opening/closing timing of the injection port H of each of the four fuel injection devices 1D, and the pressure in the four first flow paths F1 (that is, the portion PP3 FIG. 10 is a diagram showing an example of temporal changes in inner pressure). Here, these four first flow paths F1 are the first flow paths F1 of the four fuel injection devices 1D. However, in FIG. 11, in order to simplify the explanation, the case where each of the four fuel injection devices 1D does not perform injection such as pre-injection, pilot injection, etc., but performs only main injection will be described.

The horizontal axis of the graph shown in FIG. 11 indicates elapsed time. Also, the vertical axis of the graph indicates the pressure within the first flow path F1 of each of the four fuel injection devices 1D, that is, the pressure within the portion PP3. The curve F10 plotted in the graph represents the four first flows when the four fuel injectors 1D are controlled so that each of the four fuel injectors 1D injects fuel into the four combustion chambers CC2 in sequence. An example of the temporal change of the pressure in the path F1 is shown. Hereinafter, for convenience of explanation, such control of the four fuel injection devices 1D will be referred to as tenth control. The graph also includes a timing chart TC10 showing the opening/closing timing of the second flow path F2, a timing chart TC11 showing the opening/closing timing of the injection port H of the first fuel injection device 1D1, and a timing chart TC11 showing the opening/closing timing of the injection port H of the first fuel injection device 1D1. A timing chart TC12 showing the opening/closing timing of the injection port H of the third fuel injection device 1D3, a timing chart TC13 showing the opening/closing timing of the injection port H of the fourth fuel injection device 1D4, is superimposed with a timing chart TC14 showing . Further, in FIG. 10, the period in which the piston of the internal combustion engine EG rotates once is indicated by an arrow with the words "engine 1 rotation".

In the example shown in FIG. 11, the fuel injection system 10 starts opening the second flow path F2 by the driving section A2 at timing t11. As a result, as indicated by the curve F10, in the fuel injection system 10, the pressure in the first flow path F1 of each of the four fuel injection devices 1D, that is, the pressure in the portion PP3 begins to decrease. This is because the fuel begins to flow from the portion PP3 to the second flow path F2 at timing t11.

After that, in the fuel injection system 10 controlled by the tenth control, the drive unit A2 starts moving the second valve V2 so that the second flow path F2 is closed at timing t12 when a predetermined eleventh time has elapsed from timing t11. . As a result, in the fuel injection system 10, the pressure inside the first flow path F1 of each of the four fuel injection devices 1D starts to rise at timing t12.

Then, in the fuel injection device 1 controlled by the tenth control, the pressure in the portion PP3 momentarily becomes higher than the predetermined pressure Pb at the timing after the timing t12. This is because the fuel flowing from the portion PP3 through the second flow path F2 to the discharge port is dammed by the second valve V2, and the resulting water hammer action instantly raises the pressure in the portion PP3 to a predetermined level. is higher than the pressure Pb of . More specifically, the fuel that has flowed from the portion PP3 through the second flow path F2 to the discharge port is dammed in the second flow path F2 by the second valve V2 at timing t12. The dammed fuel is compressed according to the flow velocity of the fuel before dammed. As a result, a water hammer action occurs and the pressure in part PP3 begins to rise.

However, as indicated by the curve F10, the pressure in the portion PP3 damps and oscillates after timing t12. Therefore, the fuel injection system 10 controlled by the tenth control starts opening the injection port H of the first fuel injection device 1D1 at timing t13. At timing t13, the pressure in the portion PP3 rises from the pressure less than the predetermined pressure Pb to the pressure exceeding the predetermined pressure Pb among the timings after the timing t12, and then the pressure in the portion PP3 starts falling again. Any timing may be used as long as the timing is within the period between. In the example shown in FIG. 11, the timing t13 is the timing after the timing t12 when the pressure in the portion PP3 returns from the pressure lower than the predetermined pressure Pb to the predetermined pressure Pb.

The time difference between the timing t12 and the timing t13 is determined, for example, by trial and error in advance tests, experiments, etc., so that the combustion efficiency of the fuel approaches the desired combustion efficiency (for example, the highest combustion efficiency, etc.). , may be determined based on theoretical calculation, may be determined by simulation, or may be determined by other methods. At the timing t13 thus determined, the injection port H of the first fuel injection device 1D1 begins to open, so the fuel in the portion PP3 is injected at the timing t13 by a pressure higher than the predetermined pressure Pb. H starts to be injected into the combustion chamber CC2-1.

After timing t13, in the fuel injection system 10 controlled by the tenth control, at timing t14 when a predetermined twelfth time has elapsed from timing t13, the first injection device 1D1 closes the injection port H. The driving part A1 of the fuel injector 1D1 starts to move the first valve V1 of the first fuel injector 1D1. Then, at timing t14, in the fuel injection system 10, the first valve V1 closes the injection port H.

After timing t14, the fuel injection system 10 controlled by the tenth control waits with the injection port H of the first fuel injection device 1D1 closed until the next fuel injection by the first fuel injection device 1D1 is started. do. Further, in the fuel injection system 10, at timing t15 when a predetermined thirteenth time has elapsed from timing t14, the second flow path F2 is started to open again by the driving portion A2. As a result, as indicated by the curve F10, in the fuel injection system 10, the pressure in the first flow path F1 of each of the four fuel injection devices 1D, that is, the pressure in the portion PP3 begins to decrease. Here, the thirteenth time is determined so that the timing after the timing at which the pressure oscillation in the portion PP3 from timing t2 due to the water hammer action subsides is timing t15.

The fuel injection system 10 controlled by the tenth control causes each of the four fuel injection devices 1D to repeatedly perform such fuel injection in a predetermined order. That is, each of timing t15, timing t19, timing t23, timing t27, timing t31, and timing t35 indicates the timing at which the second flow path F2 starts opening in such repeated fuel injection. Timing t16, timing t20, timing t24, timing t28, timing t32, and timing t36 each indicate the timing at which the second flow path F2 closes in such repeated fuel injection. Timing t17 indicates the timing at which the injection port H of the third fuel injection device 1D3 begins to open in such repeated fuel injection. Timing t18 indicates the timing at which the injection port H of the third fuel injection device 1D3 is closed during such repeated fuel injection. Timing t21 indicates the timing at which the injection port H of the fourth fuel injection device 1D4 begins to open during such repeated fuel injection. Timing t22 indicates the timing at which the injection port H of the fourth fuel injection device 1D4 is closed during such repeated fuel injection. Timing t25 indicates the timing at which the injection port H of the second fuel injection device 1D2 begins to open in such repeated fuel injection. Timing t26 indicates the timing at which the injection port H of the second fuel injection device 1D2 is closed during such repeated fuel injection. Timing t29 indicates the timing at which the injection port H of the first fuel injection device 1D1 begins to open again in such repeated fuel injection. Timing t30 indicates the timing at which the injection port H of the first fuel injection device 1D1 is closed during such repeated fuel injection. Timing t33 indicates the timing at which the injection port H of the third fuel injection device 1D3 begins to open again in such repeated fuel injection. Timing t34 indicates the timing at which the injection port H of the third fuel injection device 1D3 is closed during such repeated fuel injection. Timing t37 indicates the timing at which the injection port H of the fourth fuel injection device 1D4 begins to open again in such repeated fuel injection. Timing t38 indicates the timing at which the injection port H of the fourth fuel injection device 1D4 is closed during such repeated fuel injection.

The fuel injection system 10 rotates the piston of the internal combustion engine EG by causing each of the four fuel injection devices 1D to repeatedly inject fuel into each combustion chamber CC2. As a result, the fuel injection system 10 can inject fuel at a pressure higher than the predetermined pressure Pb each time fuel is injected into each combustion chamber CC2. However, the fuel injection system 10 does not have a second valve V2 for each of the four fuel injection devices 1D, but has one common second valve V2. is causing Therefore, the fuel injection system 10 can improve the fuel combustion efficiency of the internal combustion engine EG while reducing the number of parts of the internal combustion engine EG. In other words, the fuel injection system 10 can reduce manufacturing costs.

The ECU 3 described above opens and closes the first to third valves V1 to V3 in accordance with the timings stored in the storage unit 32 in advance. A user causes the fuel injection device 1 to open and close each of the first to third valves V1 to V3 at the user's desired timing by pre-storing the user's desired timing in the storage unit 32 . Here, the timing pre-stored in the storage unit 32 may be represented by time, may be represented by elapsed time from a reference time, or may be represented by another known method. It may be represented by a developed method.

As described above, the fuel injection device according to the embodiment (the fuel injection device 1 and the fuel injection device 1A in the examples described above) supplies fuel to the internal combustion engine (the internal combustion engine EG in the example described above). A fuel injection device that injects into a combustion chamber (inside the combustion chamber CC in the example described above), and includes an injection port (injection port H in the example described above) that injects fuel into the combustion chamber, and fuel is supplied at a predetermined pressure (predetermined pressure Pb in the example described above) and a high pressure source (high pressure source 4 in the example described above) is connected to the injection port, and fuel is supplied from the high pressure source A first flow path (first flow path F1 in the example described above), and a first valve (first valve V1 in the example described above) provided in the first flow path for opening and closing the injection port. and a second flow path connected to the first flow path and supplied with fuel from the first flow path (in the example described above, the second flow path F2); and a second valve (in the example described above, the second valve V2) that opens and closes the flow path. This allows the fuel injector to inject fuel at a pressure higher than the pressure of the high pressure source.

Further, the fuel injection device includes a first drive section (drive section A1 in the example described above) that causes the first valve to open and close the injection port, and a second drive section that causes the second valve to open and close the second flow path. 2 drive units (drive unit A2 in the example described above) and a control unit (ECU 3 and control unit 36 in the example described above) that controls the first drive unit and the second drive unit A configuration may be used.

Further, in the fuel injection device, the control unit controls the first drive unit and the second drive unit to perform the first injection process of injecting the fuel from the injection port into the combustion chamber. a first step of opening the second flow passage by the second valve while the valve is closing the injection port; a second step of closing the second flow path by the two valves; and a third step of opening the injection port by the first valve at a timing after the second valve closes the second flow path in the second step. Any configuration may be used.

A fuel injection device is a fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine, and includes an injection port for injecting fuel into the combustion chamber, a high-pressure source for supplying fuel at a predetermined pressure, and an injection port. A first flow path to which fuel is supplied from a high-pressure source, a first valve provided in the first flow path for opening and closing the injection port, and a first valve connected to the first flow path to supply fuel from the first flow path. a second flow path to which is supplied; a second valve provided in the second flow path for opening and closing the second flow path; A portion located upstream of the first valve in the flow path and downstream of a connection portion between the first flow path and the second flow path in the first flow path among the portions of the first flow path. a third valve (in the example described above, the third valve V3) that opens and closes the portion located in the first flow path, the first valve is in a state where the injection port is closed, and , when the third valve closes the first flow path, a space (space S in the example described above) in which fuel is held is formed. This allows the fuel injector to inject fuel at a pressure higher than the pressure of the high pressure source.

In addition, the fuel injection device includes a first drive section that causes the first valve to open and close the injection port, a second drive section that causes the second valve to open and close the second flow path, and a third valve that causes the first flow path to open and close. A third drive section (drive section A3 in the example described above) that opens and closes the path, and a control section (the example described above) that controls the first drive section, the second drive section, and the third drive section. Then, a configuration further including the ECU 3 and the control unit 36) may be used.

Further, in the fuel injection device, the control unit controls the first drive unit, the second drive unit, and the third drive unit, performs the second injection process of injecting the fuel from the injection port into the combustion chamber, and performs the second injection process. includes an eleventh step in which the second valve opens the second flow path while the third valve closes the first flow path, and a predetermined After the first time has passed, a twelfth step of closing the second flow path by the second valve; a thirteenth step of opening the passageway; a fourteenth step of closing the first passageway by the third valve after a predetermined second time elapses after the third valve opens the first passageway in the thirteenth step; and a fifteenth step of opening the injection port by the first valve during a period from the time when the third valve opens the first flow path in step 13 to the time when the third valve closes the first flow path in step 14. configuration may be used.

Further, the fuel injection system according to the embodiment (the fuel injection system 10 in the example described above) includes a first fuel injection device (the fuel injection device in the example described above) that injects fuel into the combustion chamber of the internal combustion engine. 1, fuel injection device 1A, fuel injection device 1B, fuel injection device 1C) and a second fuel injection device that injects fuel into the combustion chamber (in the example described above, fuel injection device 1, fuel injection device 1A, fuel Injection device 1B, fuel injection device 1C) is connected to a high-pressure source that supplies fuel at a predetermined pressure, and the 0th flow path to which fuel is supplied from the high-pressure source (in the example described above, the 0th flow path F0 ), a second flow path connected to the 0th flow path and supplied with fuel from the 0th flow path, and a second valve provided in the second flow path for opening and closing the second flow path. , the first fuel injection device connects the 11th injection port (the injection port H in the example described above) for injecting fuel into the combustion chamber, the 0th flow path and the 11th injection port, and supplies fuel from the high pressure source. An eleventh flow path (the first flow path F1 in the example described above) to which fuel is supplied, and an eleventh valve (the example described above) that is provided in the eleventh flow path and opens and closes the eleventh injection port. The second fuel injection device includes a 21st injection port (in the example described above, the injection port H) for injecting fuel into the combustion chamber, a 0th flow path and a 1st valve V1). A 21st flow path (the first flow path F1 in the example described above) connected to the 21st injection port and supplied with fuel from a high pressure source, and a 21st flow path provided in the 21st flow path for opening and closing the 21st injection port. and a twenty-first valve (in the example described above, the first valve V1). This allows the fuel injection system to inject fuel at a pressure higher than the pressure of the high pressure source 4 .

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. may be

Also, a program for realizing the function of any component in the above-described device (e.g., ECU 3) is recorded on a computer-readable recording medium, and the program is read and executed by a computer system. may The term "computer system" as used herein includes hardware such as an OS (Operating System) and peripheral devices. In addition, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROM, CD (Compact Disk)-ROM, etc., and storage devices such as hard disks built into computer systems. . In addition, "computer-readable recording medium" means a volatile memory (RAM) inside a computer system that acts as 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. , includes those that hold the program for a certain period of time.

Moreover, the above program may be transmitted from a computer system storing this program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in a 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.
Also, the above program may be for realizing part of the functions described above. Furthermore, the above program may be a so-called difference file (difference program) that can realize the functions described above in combination with a program already recorded in the computer system.

REFERENCE SIGNS

LIST

1, 1A, 1B, 1C... fuel injection device, 2... fuel injector, 4... high pressure source, 10... fuel injection system, 32... storage unit, 33... first valve drive circuit, 34... second valve drive circuit, 35 Third valve drive circuit 36 Control section A1, A2, A3 Drive section CC Combustion chamber EG Internal combustion engine F0 0th flow path F1 1st flow path F2 2nd flow Path, H... injection port, S... space, V1... first valve, V2... second valve, V3... third valve

Claims

A fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine,
an injection port for injecting the fuel into the combustion chamber;
a first flow path that connects a high-pressure source that supplies the fuel at a predetermined pressure to the injection port, and that supplies the fuel from the high-pressure source;
a first valve provided in the first flow path for opening and closing the injection port;
a second flow path connected to the first flow path and supplied with the fuel from the first flow path;
a second valve provided in the second flow path for opening and closing the second flow path;
A fuel injector with a
a first driving unit that causes the first valve to open and close the injection port;
a second drive unit that causes the second valve to open and close the second flow path;
a control unit that controls the first driving unit and the second driving unit;
2. The fuel injector of claim 1, further comprising:
The control unit controls the first drive unit and the second drive unit to perform a first injection process of injecting the fuel from the injection port into the combustion chamber,
In the first injection process,
a first step of opening the second flow path with the second valve in a state where the first valve closes the injection port;
a second step of closing the second flow path by the second valve after a predetermined time has elapsed since the second valve opened the second flow path in the first step;
a third step of opening the injection port by the first valve at a timing after the second valve closes the second flow path in the second step;
It is included,
3. A fuel injection system according to claim 2.
A fuel injection device for injecting fuel into a combustion chamber of an internal combustion engine,
an injection port for injecting the fuel into the combustion chamber;
a first flow path that connects a high-pressure source that supplies the fuel at a predetermined pressure to the injection port, and that supplies the fuel from the high-pressure source;
a first valve provided in the first flow path for opening and closing the injection port;
a second flow path connected to the first flow path and supplied with the fuel from the first flow path;
a second valve provided in the second flow path for opening and closing the second flow path;
A portion of the portion of the first flow path that is positioned upstream of the first valve in the first flow path, and of the portion of the first flow path, the a third valve provided at a portion located downstream of a connection portion between the first flow path and the second flow path, the valve opening and closing the first flow path;
with
A space in which the fuel is held in the first flow path when the first valve closes the injection port and the third valve closes the first flow path. is formed,
fuel injector.
a first driving unit that causes the first valve to open and close the injection port;
a second drive unit that causes the second valve to open and close the second flow path;
a third drive unit that causes the third valve to open and close the first flow path;
a control unit that controls the first driving unit, the second driving unit, and the third driving unit;
5. The fuel injector of claim 4, further comprising:
The control unit controls the first driving unit, the second driving unit, and the third driving unit, and performs a second injection process of injecting the fuel from the injection port into the combustion chamber,
In the second injection process,
an eleventh step of opening the second flow path with the second valve in a state where the third valve closes the first flow path;
a twelfth step of closing the second flow path by the second valve after a predetermined first time has elapsed since the second valve opened the second flow path in the eleventh step;
a thirteenth step of opening the first flow path by the third valve at a timing after the second valve closes the second flow path in the twelfth step;
a fourteenth step of closing the first flow path by the third valve after a predetermined second time has elapsed since the third valve opened the first flow path in the thirteenth step;
During the period from when the third valve opens the first flow path in the thirteenth step to when the third valve closes the first flow path in the fourteenth step, the injection port is a fifteenth step of opening
It is included,
6. A fuel injection system according to claim 5.
a first fuel injection device that injects fuel into a first combustion chamber of a plurality of combustion chambers of an internal combustion engine;
a second fuel injection device for injecting the fuel into a second one of the plurality of combustion chambers; and a high-pressure source for supplying the fuel at a predetermined pressure, and the fuel is supplied from the high-pressure source. a 0th flow path;
a second flow path connected to the 0 flow path and supplied with fuel from the 0 flow path;
a second valve provided in the second flow path for opening and closing the second flow path;
with
The first fuel injection device,
an eleventh injection port that injects the fuel into the first combustion chamber;
an 11th flow path connecting the 0th flow path and the 11th injection port and supplied with the fuel from the high pressure source;
an eleventh valve provided in the eleventh flow path for opening and closing the eleventh injection port;
with
The second fuel injection device,
a twenty-first injection port that injects the fuel into the second combustion chamber;
a 21st flow path connecting the 0th flow path and the 21st injection port and supplied with the fuel from the high pressure source;
a 21st valve provided in the 21st flow path for opening and closing the 21st injection port;
comprising
fuel injection system.
A control method for a fuel injection device that injects fuel into a combustion chamber of an internal combustion engine,
The fuel injection device
an injection port for injecting the fuel into the combustion chamber;
a first flow path that connects a high-pressure source that supplies the fuel at a predetermined pressure to the injection port, and that supplies the fuel from the high-pressure source;
a first valve provided in the first flow path for opening and closing the injection port;
a first driving unit that causes the first valve to open and close the injection port;
a second flow path connected to the first flow path and supplied with the fuel from the first flow path;
a second valve provided in the second flow path for opening and closing the second flow path;
a second drive unit that causes the second valve to open and close the second flow path;
with
The control method is
a first step of opening the second flow path with the second valve in a state where the first valve closes the injection port;
a second step of closing the second flow path by the second valve after a predetermined time has elapsed since the second valve opened the second flow path in the first step;
a third step of opening the injection port by the first valve at a timing after the second valve closes the second flow path in the second step;
having
control method.
A control method for a fuel injection device that injects fuel into a combustion chamber of an internal combustion engine,
The fuel injection device
an injection port for injecting the fuel into the combustion chamber;
a first flow path that connects a high-pressure source that supplies the fuel at a predetermined pressure to the injection port, and that supplies the fuel from the high-pressure source;
a first valve provided in the first flow path for opening and closing the injection port;
a first driving unit that causes the first valve to open and close the injection port;
a second flow path connected to the first flow path and supplied with the fuel from the first flow path;
a second valve provided in the second flow path for opening and closing the second flow path;
a second drive unit that causes the second valve to open and close the second flow path;
A portion of the portion of the first flow path that is positioned upstream of the first valve in the first flow path, and of the portion of the first flow path, the a third valve provided at a portion located downstream of a connection portion between the first flow path and the second flow path, the valve opening and closing the first flow path;
a third drive unit that causes the third valve to open and close the first flow path;
with
A space in which the fuel is held in the first flow path when the first valve closes the injection port and the third valve closes the first flow path. is formed and
The control method is
an eleventh step of opening the second flow path with the second valve in a state where the third valve closes the first flow path;
a twelfth step of closing the second flow path by the second valve after a predetermined first time has elapsed since the second valve opened the second flow path in the eleventh step;
a thirteenth step of opening the first flow path by the third valve at a timing after the second valve closes the second flow path in the twelfth step;
a fourteenth step of closing the first flow path by the third valve after a predetermined second time has elapsed since the third valve opened the first flow path in the thirteenth step;
During the period from when the third valve opens the first flow path in the thirteenth step to when the third valve closes the first flow path in the fourteenth step, the injection port is a fifteenth step of opening
having
control method.