CN110462200B - Common rail type fuel injection device - Google Patents
Common rail type fuel injection device Download PDFInfo
- Publication number
- CN110462200B CN110462200B CN201880019394.1A CN201880019394A CN110462200B CN 110462200 B CN110462200 B CN 110462200B CN 201880019394 A CN201880019394 A CN 201880019394A CN 110462200 B CN110462200 B CN 110462200B
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- Prior art keywords
- pressure
- common rail
- fuel injection
- reducing valve
- air
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
- F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
Provided is a common rail type fuel injection device capable of preventing air from flowing into an injector when a crankshaft rotates. The common rail fuel injection device is provided with: a common rail having a pressure reducing valve for storing fuel at high pressure; a detection unit that detects a pressure in the common rail; and a control unit that determines whether or not air is mixed at predetermined time intervals based on the pressure obtained from the detection unit when the crankshaft rotates, and opens the pressure reducing valve during a drive time shorter than the predetermined time when it is determined that air is mixed.
Description
Technical Field
The present invention relates to a common rail type fuel injection device.
Background
Conventionally, there is a common rail type fuel injection device in which fuel in a fuel tank is pressurized by a high-pressure pump and pressure-fed to a common rail, and high-pressure fuel is injected into an engine through an injector connected to the common rail.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2005-291075
Disclosure of Invention
Problems to be solved by the invention
However, for example, after the engine is stopped, if the engine is not operated for a long time, air may enter the high-pressure pump from a fuel tank or the like. This air flows from the high-pressure pump through the common rail to the injectors as the crankshaft rotates. Thus, air is injected from the injector together with fuel, and therefore there are the following problems: the fuel cannot be injected in an accurate injection amount, and the engine may not be started.
The invention provides a common rail type fuel injection device capable of preventing air from flowing into an injector when a crankshaft rotates.
Means for solving the problems
The common rail fuel injection device of the present invention includes:
a common rail having a pressure reducing valve for storing fuel at high pressure;
a detection unit that detects a pressure in the common rail; and
and a control unit that determines whether or not air is mixed at predetermined time intervals based on the pressure obtained from the detection unit when the crankshaft rotates, and opens the pressure reducing valve during a drive time shorter than the predetermined time when it is determined that air is mixed.
Effects of the invention
According to the present invention, it is possible to prevent air from flowing into the injector when the crankshaft rotates.
Drawings
Fig. 1 is a block diagram showing an example of the overall configuration of a common rail fuel injection device according to an embodiment of the present invention.
Fig. 2 is a flowchart showing the air bleeding process at the time of cranking.
Fig. 3 is a timing chart showing an example of the operation of the common rail fuel injection device in the present embodiment.
Fig. 4 is a block diagram showing an example of the overall configuration of a common rail fuel injection device according to a modification.
Detailed Description
An embodiment of the present invention will be described in detail below with reference to the drawings.
The structure of a common rail fuel injection device 100 according to an embodiment of the present invention will be described with reference to fig. 1.
Fig. 1 is a block diagram showing an example of the overall configuration of a common rail fuel injection device 100. The internal combustion engine 1 mounted with the common rail type fuel injection device 100 is a diesel engine having a plurality of cylinders.
The common rail fuel injection device 100 shown in fig. 1 includes: the fuel injection system includes an injector 2, a common rail 3, a pressure-feed pump 4, a pressure reducing valve 5, a pressure sensor 10 (corresponding to a "detection unit" of the present invention), and an Electronic Control Unit (ECU)20 (corresponding to a "control unit" of the present invention).
The injector 2 directly injects fuel into the cylinder.
The common rail 3 stores the fuel supplied to the injectors 2 in a high-pressure state.
The pressure-feed pump 4 pressure-feeds the fuel to the common rail 3. The pressure-feed pump 4 includes a supply pump 12 and a high-pressure pump 13.
The feed pump 12 is a pump for drawing fuel from the fuel tank 11.
The high-pressure pump 13 is a pump that sucks in low-pressure fuel from the feed pump 12 and discharges high-pressure fuel. The high-pressure pump 13 has a plunger (not shown) that slides in a pump cylinder to discharge high-pressure fuel.
The pressure reducing valve 5 is provided at one end portion in the longitudinal direction of the common rail 3. The pressure reducing valve 5 is connected to the fuel tank 11 via a fuel return passage. The pressure reducing valve 5 is opened and closed to allow the fuel in the common rail 3 to flow back to the fuel tank 11 through the fuel return passage. The pressure reducing valve 5 is configured to be capable of changing an opening degree. The pressure reducing valve 5 is electronically controlled by a pressure reducing valve drive signal (described later) from the ECU 20.
The pressure sensor 10 is provided at the other end portion in the longitudinal direction of the common rail 3. The pressure sensor 10 detects the common rail pressure Pc.
Various sensors are electrically connected to the ECU 20. Specifically, the pressure sensor 10 is electrically connected to the ECU 20. The ECU20 obtains the common rail pressure Pc at predetermined time intervals T1 while the crankshaft is rotating.
The ECU20 determines whether air is mixed in the common rail 3 based on the common rail pressure Pc (referred to as "air mixing determination"). In the present embodiment, the ECU20 determines that air is mixed in the common rail 3 when the common rail pressure Pc is lower than the predetermined value Pa (see fig. 2). The predetermined value Pa is determined according to the engine model.
A crank speed detection sensor 16 for detecting the crank speed is electrically connected to the ECU 20. The ECU20 obtains the crank speed. The ECU20 determines a predetermined time T1 and a drive time T2 (described later) based on the crank speed. The times T1, T2 are stored in the internal memory of the ECU 20. Here, as shown in fig. 3, the relationship between the times T1 and T2 is T1> T2. For example, a time T1 at which the common rail pressure Pc can be obtained a plurality of times in the rotation of the crankshaft, and a time T2 smaller than the time T1 are stored in the internal memory of the ECU 20. The faster the crankshaft rotation speed, the shorter the time T1 and T2 are set. The times T1 and T2 were determined from the results of experiments and simulations.
The ECU20 includes: a timer (not shown), a comparison unit 22, and a pressure reducing valve control unit 24.
The comparison unit 22 compares the common rail pressure Pc with a predetermined value Pa when the crankshaft rotates. The comparison unit 22 outputs the result of the comparison to the pressure reducing valve control unit 24.
The pressure reducing valve control unit 24 opens and closes the pressure reducing valve 5 by a pressure reducing valve drive signal. By opening the pressure reducing valve 5, the common rail pressure Pc is reduced, and the fuel returns to the fuel tank 11. When air is mixed in the common rail 3, the air is discharged from the common rail 3 together with the fuel (referred to as "bleed air"). The pressure reducing valve control unit 24 changes the opening degree of the pressure reducing valve 5 by a pressure reducing valve drive signal. Thereby, the amounts of fuel and air that return to the fuel tank 11 are adjusted.
The pressure reducing valve control unit 24 opens the pressure reducing valve 5 for a driving time T2 at intervals of a predetermined time T1 until the common rail pressure Pc becomes equal to or higher than the predetermined value Pa, based on the result of comparing the common rail pressure Pc with the predetermined value Pa.
< air bleeding processing during cranking >
Next, an example of the air bleeding process during cranking will be described with reference to fig. 2. Note that the processing shown in fig. 2 is executed when the power is turned on.
In step S100, the ECU20 determines whether cranking has started. When cranking has started (step S100: yes), the ECU20 transfers the process to step S110. When cranking is not started (step S100: no), the ECU20 returns the processing to step S100.
In step S110, the ECU20 obtains the common rail pressure Pc.
In step S120, the ECU20 clears the timer and counts the elapsed time T since the common rail pressure Pc was obtained.
In step S130, the ECU20 (specifically, the comparison unit 22) compares the common rail pressure Pc with the predetermined value Pa. When the common rail pressure Pc is equal to or higher than the predetermined value Pa (no in step S130), the ECU20 (specifically, the pressure reducing valve control unit 24) ends the process. On the other hand, when the common rail pressure Pc is less than the predetermined value Pa (yes in step S130), the ECU20 opens the pressure reducing valve 5 for a drive time T2 (step S140). This discharges the air in the common rail 3. After that, the ECU20 shifts the process to step S150.
In step S150, the ECU20 discards the common rail pressure Pc.
In step S160, the ECU20 determines whether the elapsed time T is equal to or longer than a predetermined time T1.
When the elapsed time T is equal to or longer than the predetermined time T1 (yes in step S160), the ECU20 proceeds the process to step S110. On the other hand, when the elapsed time T is less than the predetermined time T1 (NO at step S160), the ECU20 returns the process to step S160.
Fig. 3 is a timing chart showing an example of the operation of the common rail fuel injection device 100. In the upper side of fig. 3, the horizontal axis represents time, and the vertical axis represents the common rail pressure Pc. In addition, the common rail pressure Pc obtained by the ECU20 is indicated by an "x" symbol. In addition, in the lower side of fig. 3, the horizontal axis represents time, and the vertical axis represents the open/closed state of the pressure reducing valve 5. The predetermined period of crankshaft rotation and engine start is shown in fig. 3.
When the common rail pressure Pc obtained at T1 is less than the predetermined value Pa, the ECU20 determines that air is mixed in the common rail 3, and opens the pressure reducing valve 5 for a drive time T2 from T1 to T2 after a predetermined time T1.
Since the common rail pressure Pc obtained at T2 is also smaller than the predetermined value Pa, the ECU20 opens the pressure reducing valve 5 for a drive time T2 from T2 to T3 after a predetermined time T1 elapses, as in T1.
Since the common rail pressure Pc obtained at T3 is also smaller than the predetermined value Pa, the ECU20 opens the pressure reducing valve 5 for a drive time T2 from T4 after a predetermined time T1 has elapsed from T3, as in the case of T1 and T2.
The common rail pressure Pc obtained at t4 is equal to or higher than a predetermined value Pa. The ECU20 determines that air is not mixed in the common rail 3 and does not open the pressure reducing valve 5. The ECU20 can prevent air from flowing into the injector 2 and inject an accurate injection quantity of fuel. Therefore, the engine can be started.
< effects of the present embodiment >
As described above, the common rail fuel injection device 100 of the present embodiment includes: a common rail 3 having a pressure reducing valve 5, the common rail 3 storing fuel at high pressure; a pressure sensor 10 that detects a pressure in the common rail 3; and an ECU20 that determines whether or not the common rail pressure Pc is less than a predetermined value based on the common rail pressure Pc obtained from the pressure sensor 10 during cranking, and opens the pressure reducing valve 5 for a drive time T2 until the common rail pressure Pc becomes equal to or greater than the predetermined value Pa during a predetermined time T1 from when the common rail pressure Pc is obtained to when the common rail pressure Pc is obtained next time. Thus, when there is air mixing in the common rail 3, the air is discharged from the common rail 3 at intervals of a predetermined time T1 during cranking, and the amount of air mixing in the common rail 3 during cranking can be gradually reduced. Therefore, the inflow of air into the injector 2 can be prevented when the crankshaft rotates.
In the common rail fuel injection system 100 according to the present embodiment, the predetermined time T1 is determined based on the crank speed. Thus, since it is determined whether or not air is mixed in the common rail 3 at the time of cranking, air can be discharged from the common rail 3 during cranking based on the determination result.
In the common rail fuel injection system 100 according to the present embodiment, the drive time T2 is determined based on the crank speed. This allows air to be discharged from the common rail 3 when the crankshaft rotates, and thus prevents air from flowing into the injector 2.
In addition, according to the common rail type fuel injection device 100 of the present embodiment, the pressure reducing valve control unit 24 controls the opening degree of the pressure reducing valve 5 based on the common rail pressure Pc obtained from the pressure sensor 10. Thus, for example, if the pressure difference between the common rail pressure Pc and the predetermined value Pa is large, the opening degree is increased, and the amount of air per unit time that is discharged from the common rail 3 can be increased, so that the air can be discharged from the common rail 3 in a short time. In addition, air can be reliably discharged from the common rail 3 during cranking.
Further, according to the common rail fuel injection device 100 of the present embodiment, the degree to which the common rail pressure Pc is increased during cranking is set according to the engine model, and therefore the predetermined value Pa to be compared with the common rail pressure Pc is determined according to the engine model. Thus, the comparison unit 22 compares the common rail pressure Pc with the appropriate predetermined value Pa, and the pressure-reducing valve control unit 24 can output an appropriate pressure-reducing valve drive signal based on the result of the comparison.
< modification of the present embodiment >
Next, a modification of the present embodiment will be described with reference to fig. 4. Fig. 4 is a block diagram showing an example of the overall configuration of the common rail fuel injection device 100. In the description of the modified examples, the description will be given mainly of the configurations different from those of the above-described embodiments, and the same configurations will be given the same reference numerals and the description thereof will be omitted.
In the ECU20 of the above embodiment, the comparison unit 22 compares the common rail pressure Pc with the predetermined value Pa. The pressure reducing valve control unit 24 outputs a pressure reducing valve control signal to the pressure reducing valve 5, and opens the pressure reducing valve 5 for a drive time T2 until the common rail pressure Pc becomes equal to or higher than the predetermined value Pa.
In contrast, in the ECU20 of the modification, the pressure change amount calculation unit 26 calculates the change amount Δ P of the pressure within the predetermined time T1 at intervals of the predetermined time T1 based on the pressure obtained from the pressure sensor 10. The comparison unit 22A compares the calculated pressure change amount Δ P with a predetermined value Pb. When the amount of change Δ P in the pressure is smaller than the predetermined value Pb, the pressure reducing valve control unit 24 outputs a pressure reducing valve control signal to the pressure reducing valve 5 so that the pressure reducing valve 5 is opened for the driving time T2. Thus, when air is mixed in the common rail 3, the air is discharged from the common rail 3 during the cranking. Therefore, the inflow of air into the injector 2 can be prevented when the crankshaft rotates.
The pressure reducing valve control unit 24 increases the opening degree of the pressure reducing valve 5 in accordance with the amount of change in pressure. This enables air to be efficiently discharged from the common rail 3, thereby preventing air from flowing into the injector 2.
In the above modification, the predetermined value Pb may be determined according to the engine model. Since the amount of change in the common rail pressure Pc per predetermined time T1 when the crankshaft rotates is set according to the type of the engine, the predetermined value Pb to which the amount of change in the pressure is compared is determined according to the type of the engine. Thus, the comparison unit 22A compares the amount of change in pressure with the appropriate predetermined value Pb, and the pressure-reducing valve control unit 24 can output an appropriate pressure-reducing valve drive signal based on the result of the comparison.
The air bleeding process during cranking in the above modification can be performed in place of the air bleeding process in the above embodiment, or can be performed in combination with the air bleeding process in the above embodiment. In combination with the air bleeding process in the above embodiment, the air bleeding may be stopped when the pressure is equal to or higher than a predetermined value Pa or when the amount of change in the pressure is equal to or higher than a predetermined value Pb, or the air bleeding may be stopped when the pressure is equal to or higher than a predetermined value Pa and the amount of change in the pressure is equal to or higher than a predetermined value Pb. This makes it possible to accurately determine the air inclusion, and to more reliably start the engine.
In the above-described modification, the pressure reducing valve control unit 24 controls the pressure reducing valve 5 based on the amount of change in the pressure within the predetermined time T1, but the present invention is not limited to this, and the pressure reducing valve 5 may be controlled based on the pressure difference between the first pressure and the second pressure obtained at intervals of the predetermined time T1, or the pressure reducing valve 5 may be controlled based on the required time required until the pressure difference between the first pressure and the second pressure is generated.
Industrial applicability
The present application is based on the japanese patent application (japanese patent application laid-open No. 2017-074631) proposed at 4.4.2017, the content of which is incorporated herein by reference.
The common rail fuel injection device of the present invention is useful as a diesel engine that requires prevention of air inflow to an injector during cranking.
Description of the reference numerals
1 internal combustion engine
2 ejector
3 common rail
4 pressure feed pump
5 pressure reducing valve
10 pressure sensor
11 fuel tank
12 supply pump
13 high-pressure pump
16 crank shaft rotation speed detecting sensor
20ECU
22 comparing part
22A comparing part
24 pressure reducing valve control unit
26 pressure variation calculating part
100 common rail fuel injection apparatus.
Claims (8)
1. A common rail fuel injection device is provided with:
a common rail having a pressure reducing valve for storing fuel at high pressure;
a detection unit that detects a pressure in the common rail; and
and a control unit that determines whether or not air is mixed by setting the pressure to a shorter predetermined time every time the crank rotation speed is faster based on the pressure obtained from the detection unit when the crankshaft rotates, and opens the pressure reducing valve during a drive time shorter than the predetermined time when it is determined that air is mixed.
2. The common rail fuel injection apparatus according to claim 1,
the driving time is determined according to the rotation speed of the crankshaft.
3. The common rail fuel injection apparatus according to claim 1,
the control unit determines that the air is mixed when the pressure obtained from the detection unit is less than a first predetermined value.
4. The common rail fuel injection apparatus according to claim 3,
the control portion controls the opening degree of the pressure reducing valve according to the pressure obtained from the detection portion.
5. The common rail fuel injection apparatus according to claim 3,
the first predetermined value is determined according to the engine model.
6. The common rail fuel injection apparatus according to claim 1,
the control unit obtains the pressure at every predetermined time, and determines that the air is mixed when a variation in the pressure within the predetermined time is smaller than a second predetermined value.
7. The common rail fuel injection apparatus according to claim 6,
the second predetermined value is determined according to the engine model.
8. The common rail fuel injection apparatus according to claim 6,
the control unit controls the opening of the pressure reducing valve according to the amount of change in the pressure.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017-074631 | 2017-04-04 | ||
| JP2017074631A JP6819425B2 (en) | 2017-04-04 | 2017-04-04 | Common rail fuel injection system |
| PCT/JP2018/014092 WO2018186345A1 (en) | 2017-04-04 | 2018-04-02 | Common rail fuel injection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110462200A CN110462200A (en) | 2019-11-15 |
| CN110462200B true CN110462200B (en) | 2021-08-10 |
Family
ID=63713037
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201880019394.1A Active CN110462200B (en) | 2017-04-04 | 2018-04-02 | Common rail type fuel injection device |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP6819425B2 (en) |
| CN (1) | CN110462200B (en) |
| PH (1) | PH12019502196A1 (en) |
| WO (1) | WO2018186345A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109578159A (en) * | 2018-11-27 | 2019-04-05 | 潍柴动力股份有限公司 | A kind of large-diameter electric-control motor establishes the method and device of rail pressure |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3829573B2 (en) * | 2000-03-14 | 2006-10-04 | いすゞ自動車株式会社 | Common rail fuel injection system |
| JP3881950B2 (en) * | 2002-10-25 | 2007-02-14 | ボッシュ株式会社 | Operation control method of high pressure pump for common rail |
| JP2006022677A (en) * | 2004-07-06 | 2006-01-26 | Nissan Motor Co Ltd | Fuel system control device for internal combustion engine |
| JP4544153B2 (en) * | 2005-12-27 | 2010-09-15 | 株式会社デンソー | Fuel injection control device |
| JP5004353B2 (en) * | 2007-12-28 | 2012-08-22 | ボッシュ株式会社 | Fuel supply device for internal combustion engine and control device for fuel supply device |
| JP4525793B2 (en) * | 2008-05-08 | 2010-08-18 | トヨタ自動車株式会社 | Abnormality diagnosis apparatus and abnormality diagnosis method for fuel system |
| EP2116711B1 (en) * | 2008-05-08 | 2013-01-09 | Toyota Jidosha Kabushiki Kaisha | Malfunction diagnostic device and malfunction diagnostic method for fuel system |
| JP5195842B2 (en) * | 2010-08-18 | 2013-05-15 | 株式会社デンソー | Pressure reducing valve controller |
| JP6070442B2 (en) * | 2013-06-28 | 2017-02-01 | いすゞ自動車株式会社 | Control device for common rail fuel injection system |
-
2017
- 2017-04-04 JP JP2017074631A patent/JP6819425B2/en active Active
-
2018
- 2018-04-02 WO PCT/JP2018/014092 patent/WO2018186345A1/en active Application Filing
- 2018-04-02 CN CN201880019394.1A patent/CN110462200B/en active Active
-
2019
- 2019-09-24 PH PH12019502196A patent/PH12019502196A1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| CN110462200A (en) | 2019-11-15 |
| JP2018178754A (en) | 2018-11-15 |
| WO2018186345A1 (en) | 2018-10-11 |
| PH12019502196A1 (en) | 2020-06-08 |
| JP6819425B2 (en) | 2021-01-27 |
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