WO2019039480A1 - Vanne d'injection de carburant - Google Patents

Vanne d'injection de carburant Download PDF

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Publication number
WO2019039480A1
WO2019039480A1 PCT/JP2018/030875 JP2018030875W WO2019039480A1 WO 2019039480 A1 WO2019039480 A1 WO 2019039480A1 JP 2018030875 W JP2018030875 W JP 2018030875W WO 2019039480 A1 WO2019039480 A1 WO 2019039480A1
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WO
WIPO (PCT)
Prior art keywords
passage
valve
fuel
chamber
control chamber
Prior art date
Application number
PCT/JP2018/030875
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English (en)
Japanese (ja)
Inventor
祐樹 田名田
尚史 足立
鈴木　雅幸
利明 稗島
本也 鎌原
Original Assignee
株式会社デンソー
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2018134992A external-priority patent/JP6706290B2/ja
Application filed by 株式会社デンソー filed Critical 株式会社デンソー
Priority to DE112018004736.9T priority Critical patent/DE112018004736T5/de
Publication of WO2019039480A1 publication Critical patent/WO2019039480A1/fr
Priority to US16/795,946 priority patent/US11193464B2/en

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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
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • 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
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure

Definitions

  • the present disclosure relates to a fuel injection valve capable of controlling the inclination of the injection rate of fuel.
  • a control chamber for generating fuel pressure for controlling the lift of the needle valve is formed, and a fuel injection valve for controlling communication between the low pressure fuel passage and the high pressure fuel passage and the control chamber (See Patent Document 1). Then, the low pressure fuel passage and the control chamber are communicated with each other by the on-off valve, so that the fuel pressure in the control chamber is reduced, the needle valve is lifted, and the fuel is injected.
  • the fuel injection valve described in Patent Document 1 two low pressure fuel passages having different flow rates are formed, and the driven valve is provided with a driven valve that controls communication and shutoff between the high pressure fuel passage and the control chamber.
  • the two low pressure fuel passages are in communication with the control chamber via a passage formed in the driven valve.
  • the inclination of the injection rate of a fuel is controlled by connecting and interrupting
  • the control chamber in a state in which the driven valve shuts off the high pressure fuel passage and the control chamber, the control chamber is provided via two passages in which two low pressure fuel passages are formed in the driven valve.
  • two low pressure fuel passages communicate with the intermediate chamber, and the intermediate chamber communicates with the control chamber via one passage formed in the driven valve.
  • the driven valve in a state where the driven valve shuts off the high pressure fuel passage and the control chamber.
  • two low pressure fuel passages need to be in communication with the intermediate chamber. Therefore, in any configuration, the configuration near the driven valve is complicated.
  • the present disclosure has been made to solve the above-mentioned problems, and its main object is to simplify the configuration in the vicinity of a driven valve in a fuel injection valve capable of controlling the inclination of the injection rate of fuel.
  • the first means for solving the above problems is A fuel injection valve capable of controlling the inclination of the fuel injection rate, High pressure chamber to which high pressure fuel is supplied, injection hole for injecting fuel inside the high pressure chamber, high pressure passage to which high pressure fuel is supplied, control chamber connected to the high pressure passage, low pressure passage to discharge low pressure fuel, A first passage connected to the low pressure passage, an intermediate chamber connecting the control chamber and the first passage, and a main body provided with a second passage connecting the control chamber and the low pressure passage; A needle valve that communicates and shuts off the high pressure chamber and the injection hole based on the fuel pressure in the control chamber; A driven valve provided inside the control chamber and whose lift state is controlled based on the fuel pressure inside the intermediate chamber; An on-off valve that connects and disconnects the first passage and the low pressure passage, and connects and disconnects the second passage and the low pressure passage; Equipped with The driven valve is provided with a third passage having a first throttle which restricts the flow rate of the fuel, which is a passage penetrating the driven valve.
  • the driven valve shuts off the high pressure passage and the control chamber in a state where the control chamber and the intermediate chamber are in communication via the third passage, and the control chamber and the intermediate chamber are connected to the third passage.
  • the high pressure passage and the control chamber in communication with each other without
  • the second passage has a second throttle that limits the flow rate of fuel, and communicates with the control chamber without the driven valve.
  • the high pressure fuel is supplied to the high pressure chamber.
  • the fuel in the intermediate chamber is discharged through the first passage and the low pressure passage.
  • the fuel pressure inside the intermediate chamber decreases, and the follower valve is attracted to the intermediate chamber.
  • the high pressure passage and the control chamber are shut off by the driven valve.
  • the third passage has the first throttle that limits the flow rate of fuel, a pressure difference is generated in the fuel before and after the first throttle, and the state in which the driven valve is attracted to the intermediate chamber by this pressure difference is maintained Be done.
  • the fuel pressure in the control chamber further decreases, the high pressure chamber and the injection hole are communicated by the needle valve, and the fuel is injected from the injection hole.
  • the third passage may have the function of the first aperture by setting the third passage to have a plurality of first apertures or by setting the flow passage area of the third passage small. .
  • the fuel in the control chamber is discharged through the first passage, the second passage, and the low pressure passage.
  • the second passage has the second throttle that limits the flow rate of fuel, the fuel pressure inside the control chamber is suppressed to be lower than the fuel pressure inside the intermediate chamber, and the driven valve is in the intermediate chamber The state of being attracted to is maintained.
  • the fuel in the control chamber is discharged from the first passage and the second passage, the fuel in the control chamber is compared with the case where the fuel in the control chamber is discharged only from the first passage. The pressure drops faster. Therefore, the speed at which the needle valve lifts can be increased, and the inclination of the fuel injection rate can be increased.
  • the inclination of the fuel injection rate can be controlled by controlling the communication and blocking between the second passage and the low pressure passage by the on-off valve.
  • the second passage may have a plurality of second apertures, or the second passage itself may have a function of the second aperture by setting the flow passage area of the second passages small. .
  • the second passage communicates with the control chamber without via the driven valve
  • the configuration in which the second passage communicates with the control chamber can be simplified. That is, in the fuel injection valve, the first passage and the second passage communicate with the control chamber through two passages formed in the driven valve, respectively, or the first passage and the second passage communicate with the intermediate chamber, It is not necessary to adopt a configuration in which the intermediate chamber communicates with the control chamber via one passage formed in the driven valve. Therefore, in the fuel injection valve capable of controlling the inclination of the injection rate of the fuel, the configuration in the vicinity of the driven valve can be simplified.
  • the first passage and the low pressure passage are shut off by the on-off valve during injection of fuel, so that the control chamber and the intermediate chamber are connected to the third passage by the driven valve. It is connected without intervention.
  • the high pressure chamber and the injection hole are communicated by the needle valve, and the fuel is injected from the injection hole.
  • the first passage and the low pressure passage are disconnected by the on-off valve during the injection of the fuel, so that the control chamber and the intermediate chamber are communicated without the third passage by the driven valve.
  • the high pressure passage and the control chamber are in communication by the driven valve. Therefore, the fuel pressure inside the control chamber is increased, and the operation can be shifted to the operation of closing the high pressure chamber and the injection hole by the needle valve (valve closing operation).
  • the on-off valve connects the first passage and the low pressure passage with each other, and the second on-off valve connects the second passage with the low pressure passage.
  • the on-off valve includes the first on-off valve that connects and disconnects the first passage and the low pressure passage, and the second on-off valve that connects and disconnects the second passage and the low pressure passage. For this reason, communication and interruption of the first passage and the low pressure passage, and communication and interruption of the second passage and the low pressure passage can be controlled independently of each other.
  • the first on-off valve and the second on-off valve when the first on-off valve and the second on-off valve are closed, the first on-off valve is closed and the second on-off valve is opened, whereby the high pressure is increased by the needle valve.
  • the closed state of the chamber and the injection hole is maintained, and the high pressure passage and the control chamber are communicated by the driven valve.
  • the fuel in the high pressure passage can be discharged through the control chamber, the second passage, and the low pressure passage in a state where fuel injection is not performed by the fuel injection valve. Therefore, the second on-off valve can realize the function of the pressure reducing valve for reducing the fuel pressure inside the high pressure passage and hence the fuel pressure inside the portion supplying the high pressure passage.
  • the high pressure passage has a third throttle for limiting the flow rate of fuel, and in the state where the first on-off valve is closed and the second on-off valve is opened, The flow rate of fuel through the third throttle is set larger than the flow rate of fuel through the second throttle.
  • the flow rate of the fuel flowing from the high pressure passage into the control chamber via the third throttle becomes larger than the flow rate of the fuel flowing out from the control chamber via the second throttle. Therefore, even if the second passage and the control chamber are in communication with each other by the driven valve, the fuel pressure in the control chamber does not decrease, and the high pressure chamber and the injection hole are disconnected by the needle valve. Can be maintained.
  • the second on-off valve can realize the function of the pressure reducing valve for reducing the fuel pressure inside the high pressure passage and hence the fuel pressure inside the portion supplying the high pressure passage.
  • the high pressure passage may have a plurality of third throttles, or the high pressure passage itself may have the function of the third throttle by setting the flow passage area of the high pressure passages small.
  • the control chamber and the intermediate chamber are communicated with each other without the third passage by the driven valve.
  • the high pressure chamber and the injection hole are communicated by the needle valve, and the fuel is injected from the injection hole.
  • the control chamber and the intermediate chamber are communicated without the third passage by the driven valve.
  • the high pressure passage and the control chamber are in communication by the driven valve. Therefore, the fuel pressure in the control chamber is increased, and the needle valve can shift to the operation of shutting off the high pressure chamber and the injection hole.
  • the seventh means when the fuel injection is stopped, the first on-off valve and the second on-off valve are closed, and the first on-off valve is closed and the second on-off valve Can be switched to the open state. According to such a configuration, when stopping the fuel injection, it is possible to change the speed at which the fuel pressure in the control chamber rises, and to change the speed at which the needle valve descends and hence the slope of the fuel injection rate. be able to.
  • the first on-off valve and the second on-off valve are closed while the needle valve is moving in the direction to shut off the high pressure chamber and the injection hole, and the first on-off valve Is closed and the second on-off valve can be opened. According to such a configuration, it is possible to flexibly change the speed at which the needle valve descends and hence the inclination of the injection rate of the fuel while the needle valve descends.
  • the first passage and the low pressure passage are in communication and the second passage and the low pressure passage are in communication, the first passage and the low pressure passage are in communication and the second passage and the low pressure passage are blocked.
  • the speed at which the fuel pressure inside the control chamber decreases is higher.
  • the ninth means when the fuel injection is started, the first passage and the low pressure passage are in communication, and the second passage and the low pressure passage are in communication; It is possible to switch between a state in which the passage and the low pressure passage are in communication and the second passage and the low pressure passage are shut off. According to such a configuration, when fuel injection is started, the speed at which the fuel pressure in the control chamber decreases can be changed, and the speed at which the needle valve lifts and hence the inclination of the fuel injection rate can be changed. be able to.
  • the first passage and the low pressure passage are communicated with each other, and the second passage and the low pressure passage are moved while the needle valve is moving in the direction to connect the high pressure chamber and the injection hole. It is possible to switch between the communication state and the state in which the first passage and the low pressure passage are in communication and the second passage and the low pressure passage are shut off. According to such a configuration, it is possible to flexibly change the speed at which the needle valve lifts and hence the inclination of the fuel injection rate while the needle valve is being lifted.
  • the driven valve when the first passage and the low pressure passage are communicated by the on-off valve, the driven valve communicates the control chamber and the intermediate chamber via the third passage. This is realized based on the restriction of the flow rate of fuel by the first throttle, the exposed area of the driven valve in the intermediate chamber, and the setting of the exposed area of the driven valve in the high pressure passage.
  • the fuel injection valve may include a biasing member that biases the driven valve toward the intermediate chamber.
  • the needle valve In the configuration in which the needle valve is exposed to the inside of the control chamber, if the fuel pressure inside the control chamber drops sharply, the needle valve lifts rapidly and repeatedly collides with a stopper etc., and the behavior of the needle valve becomes unstable. become. On the other hand, if the speed at which the fuel pressure in the control chamber decreases is too low, the speed at which the needle valve lifts may be too low.
  • the control chamber includes a first control chamber in which the driven valve is disposed, and a second control chamber in which the needle valve is exposed
  • the main body includes: A passage connecting the first control chamber and the second control chamber and having a fourth throttle for limiting the flow rate of fuel is provided.
  • the flow rate of the fuel flowing out of the second control chamber can be limited by the fourth throttle of the fourth passage, and the speed at which the fuel pressure in the second control chamber decreases is appropriately set.
  • it can be suppressed that the pulsation of the fuel pressure is transmitted between the first control chamber and the second control chamber.
  • the fourth passage may have the function of the fourth throttle by setting the fourth passage to have a plurality of fourth throttles or setting the flow passage area of the fourth passageway small. .
  • the first on-off valve is opened, the second on-off valve is opened, and the high pressure passage and the control chamber are disconnected by the driven valve, and the high pressure chamber and the injection are opened by the needle valve.
  • the flow rate of fuel through the fourth throttle is set larger than the sum of the flow rate of fuel through the first throttle and the flow rate of fuel through the second throttle in a state in which the hole is in communication with the hole There is.
  • the flow rate of the fuel flowing into the first control chamber via the fourth passage is higher than the flow rate of the fuel flowing out of the first control chamber via the third passage and the second passage. For this reason, it can suppress that the fuel pressure inside the 1st control chamber falls too much, and it can suppress that the differential pressure which arose in the fuel before and behind the 1st throttle is reduced. Therefore, the driven valve can be maintained in a state of being attracted to the intermediate chamber by the pressure difference generated in the fuel before and after the first throttle.
  • a fourteenth means is a fuel injection system, comprising: a fuel injection valve according to any one of the first to thirteenth means; A holding vessel for holding high pressure fuel inside and supplying high pressure fuel to the high pressure chamber and the high pressure passage; A driving unit for driving the on-off valve so as to connect and disconnect the first passage and the low pressure passage and to connect and disconnect the second passage and the low pressure passage; Equipped with
  • the high pressure fuel is supplied from the holding container to the high pressure chamber and the high pressure passage.
  • the on / off valve is driven by the drive unit so as to connect and disconnect the first passage and the low pressure passage, and to connect and disconnect the second passage and the low pressure passage. Therefore, in the fuel injection system, the same function and effect as those of the above-described means can be obtained.
  • FIG. 1 is a schematic view showing a fuel injection system according to a first embodiment
  • FIG. 2 is a schematic view showing a state in which the first on-off valve is opened
  • 3 is a cross-sectional view taken along line III-III in FIG.
  • FIG. 4 is a partial enlarged view showing the vicinity of the driven valve of the comparative example
  • 5 is a cross-sectional view taken along line VV of FIG.
  • FIG. 6 is a partial enlarged view showing the vicinity of a driven valve of another comparative example
  • FIG. 7 is a graph showing the relationship between the lift amount of the needle valve and the injection rate
  • FIG. 8 is a graph showing the relationship between the lift amount and the injection rate of the needle valve of the comparative example
  • FIG. 9 is a schematic view showing a pressure reducing operation by the second on-off valve
  • FIG. 10 is a graph showing injection rate patterns at high speed rise time and high speed fall time
  • FIG. 11 is a schematic view showing the states of the first on-off valve and the second on-off valve before the start of injection
  • FIG. 12 is a schematic view showing the states of the first on-off valve and the second on-off valve at the time of high speed start-up
  • FIG. 13 is a schematic view showing the states of the first on-off valve and the second on-off valve at the time of high speed falling
  • FIG. 14 is a schematic view showing the states of the first on-off valve, the second on-off valve, and the driven valve at the time of high speed falling
  • FIG. 15 is a graph showing injection rate patterns at low speed rise and high speed fall
  • FIG. 16 is a schematic view showing the states of the first on-off valve and the second on-off valve at low speed start-up time
  • FIG. 17 is a graph showing injection rate patterns at high speed rise and low speed fall
  • FIG. 18 is a schematic view showing the states of the first on-off valve and the second on-off valve at the time of low speed falling
  • FIG. 19 is a schematic view showing the states of the first on-off valve, the second on-off valve, and the driven valve at low speed falling.
  • FIG. 15 is a graph showing injection rate patterns at low speed rise and high speed fall
  • FIG. 16 is a schematic view showing the states of the first on-off valve and the second on-off valve at low speed start-up time
  • FIG. 17 is a graph showing injection rate patterns at high
  • FIG. 20 is a graph showing injection rate patterns at low speed rise and low speed fall
  • FIG. 21 is a graph showing an injection rate pattern when changing from low speed start to high speed start
  • FIG. 22 is a graph showing an injection rate pattern at the time of change from high speed rise to low speed rise
  • FIG. 23 is a graph showing an injection rate pattern when changing from high speed falling to low speed falling
  • FIG. 24 is a graph showing the injection rate pattern when changing from low speed falling to high speed falling
  • FIG. 25 is a time chart showing the operation at low speed rise and high speed fall
  • FIG. 26 is a time chart showing operations at high-speed rise and low-speed fall
  • FIG. 27 is a time chart showing the operation at the time of change from low speed rise to high speed rise
  • FIG. 28 is a time chart showing an operation at the time of change from high-speed falling to low-speed falling
  • FIG. 29 is a schematic view showing a fuel injection system according to a second embodiment
  • FIG. 30 is a schematic view showing the state of the on-off valve at the time of high speed start-up
  • FIG. 31 is a schematic view showing the state of the on-off valve at low speed start-up
  • FIG. 32 is a schematic view showing a modification of the second passage
  • FIG. 33 is a schematic view showing another modification of the second passage
  • FIG. 34 is a schematic view showing a modification of the needle valve
  • FIG. 35 is a schematic view showing another modification of the needle valve
  • FIG. 36 is a partial cross-sectional view showing a modification of the first embodiment
  • FIG. 37 is a cross-sectional view showing a part of FIG. 36 in an enlarged manner.
  • a first embodiment embodied in a fuel injection system applied to an automobile (vehicle) engine (internal combustion engine) will be described with reference to the drawings.
  • the engine can use liquid fuel such as light oil, gasoline, and mixed fuel mixed with ethanol as fuel.
  • a diesel engine will be described as an example.
  • the fuel injection system 10 includes a common rail 11, a high pressure pipe 12, a fuel injection valve 20, and an ECU 90.
  • High pressure fuel is supplied to the common rail 11 (corresponding to a holding container) from a high pressure pump (not shown).
  • the common rail 11 internally holds high pressure fuel under high pressure.
  • Each fuel injection valve 20 (only one is shown in FIG. 1) is connected to the common rail 11 via each high pressure pipe 12.
  • the common rail 11 is not provided with a pressure reducing valve for reducing the fuel pressure in the common rail 11.
  • the fuel injection valve 20 includes first to fourth members 21 to 24, a needle valve 31, a spring 32, a follower valve 41, a spring 45, a first on-off valve 51, a second on-off valve 52, a first solenoid 53, and a second solenoid. 54, a first spring 55, a second spring 56 and the like.
  • the first to fourth members 21 to 24 constitute a main body.
  • a first high pressure passage 13, a low pressure chamber 57, and a low pressure passage 58 are formed in the first member 21.
  • the first high pressure passage 13 is formed across the first to third members 21 to 23 and penetrates the first to third members 21 to 23.
  • the first high pressure passage 13 is connected to the high pressure pipe 12. That is, high pressure fuel is supplied from the high pressure pipe 12 to the first high pressure passage 13.
  • the surface on the second member 22 side is open. The periphery of the opening is sealed between the first member 21 and the second member 22.
  • a low pressure passage 58 is connected to the low pressure chamber 57.
  • a low pressure pipe (not shown) is connected to the low pressure passage 58. The low pressure fuel in the low pressure chamber 57 is discharged to the outside of the fuel injection valve 20 through the low pressure passage 58.
  • a second high pressure passage 14, a first passage 25, an intermediate chamber 26, and a second passage 27 are formed.
  • the second high pressure passage 14 (corresponding to the high pressure passage) branches from the first high pressure passage 13. That is, high pressure fuel is supplied from the first high pressure passage 13 to the second high pressure passage 14.
  • the second high pressure passage 14 has a third throttle 14a and an annular chamber 14b.
  • the third throttle 14 a restricts the flow rate of fuel flowing through the second high pressure passage 14.
  • the annular chamber 14 b is an annularly formed chamber, and the surface on the third member 23 side is open. That is, the second high pressure passage 14 is connected to a first control chamber 46 described later via the annular chamber 14 b.
  • the second high pressure passage 14 itself has the function of the third restriction 14 a by setting the second high pressure passage 14 to have a plurality of third restrictors 14 a or setting the flow passage area of the second high pressure passage 14 small. You may have.
  • the intermediate chamber 26 is connected to the low pressure passage 58 via the first passage 25 and the low pressure chamber 57.
  • the intermediate chamber 26 is a chamber formed in a cylindrical shape, and the surface on the third member 23 side is open. That is, the intermediate chamber 26 connects the first passage 25 and a first control chamber 46 described later.
  • One end of the second passage 27 is connected to the low pressure chamber 57, and the other end of the second passage 27 is connected to the first control chamber 46. That is, the second passage 27 connects the low pressure chamber 57 and the first control chamber 46.
  • the second passage 27 has a second throttle 27a.
  • the second throttle 27 a is provided at an end of the second passage 27 on the low pressure chamber 57 (second on-off valve 52) side.
  • the second throttle 27a restricts the flow rate of the fuel flowing through the second passage 27.
  • the second passage 27 itself has the function of the second throttle 27 a by the second passage 27 having a plurality of second throttles 27 a or by setting the flow passage area of the second passages 27 small. You may
  • a first control chamber 46 and a connection passage 47 are formed in the third member 23.
  • the first control chamber 46 is open at the surface on the second member 22 side. The periphery of the opening is sealed between the second member 22 and the third member 23.
  • a connection passage 47 is connected to the first control chamber 46.
  • the connection passage 47 is connected to a second control chamber 36 described later. That is, the connection passage 47 (corresponding to the fourth passage) connects the first control chamber 46 and the second control chamber 36.
  • the connection passage 47 has a fourth stop 47a.
  • the fourth throttle 47 a restricts the flow rate of fuel flowing through the connection passage 47.
  • the connection passage 47 has a plurality of fourth apertures 47 a, or the connection passage 47 itself has the function of the fourth aperture 47 a by setting the flow passage area of the connection passage 47 small. It is also good.
  • a high pressure chamber 33, an injection hole 34, a cylinder 35, and a second control chamber 36 are formed in the fourth member 24.
  • the high pressure chamber 33 is connected to the first high pressure passage 13, the second control chamber 36, and the injection hole 34. That is, high pressure fuel is supplied from the first high pressure passage 13 to the high pressure chamber 33.
  • the injection holes 34 communicate with the outside of the fourth member 24.
  • a needle valve 31 is disposed inside the fourth member 24.
  • the tip of the needle valve 31 is formed in a conical shape, and the portion excluding the tip of the needle valve 31 is formed in a cylindrical shape.
  • the cylinder 35 supports the needle valve 31 so as to be capable of reciprocating.
  • a spring 32 is disposed which biases the needle valve 31 in the direction approaching the injection hole 34.
  • the end face of the needle valve 31 opposite to the injection hole 34 is exposed to the inside of the second control chamber 36.
  • the first control room 46 and the second control room 36 constitute a control room.
  • the needle valve 31 is maintained with the high pressure chamber 33 and the injection hole 34 shut off, or the needle valve 31 is the injection hole 34 Move in the direction of In a state where the fuel pressure in the second control chamber 36 is lower than the predetermined pressure, the needle valve 31 moves in the direction of the third member 23 or the needle valve 31 communicates the high pressure chamber 33 and the injection hole 34 Maintained by As a result, high pressure fuel in the high pressure chamber 33 is injected from the injection holes 34. That is, the needle valve 31 communicates and shuts off the high pressure chamber 33 and the injection hole 34 based on the fuel pressure in the second control chamber 36.
  • the driven valve 41 is disposed inside the first control chamber 46 in the third member 23.
  • the driven valve 41 is formed in a cylindrical shape.
  • the driven valve 41 is formed with a third passage 42 penetrating the driven valve 41 in the central axial direction.
  • the third passage 42 has a first throttle 42 a.
  • the first throttle 42 a restricts the flow rate of fuel flowing through the third passage 42.
  • the third passage 42 itself has the function of the first throttle 42 a because the third passage 42 has a plurality of first throttles 42 a or the flow passage area of the third channel 42 is set small. It may be
  • a spring 45 is disposed which biases the driven valve 41 in a direction toward the intermediate chamber 26 (second member 22).
  • the intermediate chamber 26 is in communication with the first control chamber 46 through the third passage 42, and the opening on the third member 23 of the annular chamber 14 b is the driven valve 41. It is closed by
  • the driven valve 41 is separated from the second member 22, the intermediate chamber 26 is in communication with the first control chamber 46 without passing through the third passage 42, and the annular chamber 14 b is in communication with the first control chamber 46.
  • the second passage 27 communicates with the first control chamber 46 without the driven valve 41. That is, regardless of the position (lift state) of the driven valve 41, the second passage 27 directly connects the low pressure chamber 57 and the first control chamber 46.
  • a first on-off valve 51, a second on-off valve 52, a first solenoid 53, a second solenoid 54, a first spring 55, and a second spring 56 are disposed in the low pressure chamber 57 of the first member 21.
  • the first spring 55 biases the first open / close valve 51 (corresponding to the open / close valve) in a direction to approach the first passage 25.
  • the first on-off valve 51 shuts off the first passage 25 and the low pressure chamber 57 (that is, the low pressure passage 58).
  • the first on-off valve 51 does not have a portion that slides with the first passage 25 (the second member 22), and opens and closes the open end of the first passage 25.
  • first on-off valve 51 shuts off the first passage 25 and the low pressure chamber 57
  • fuel does not leak between the first passage 25 and the low pressure chamber 57. That is, the first on-off valve 51 has a leakless structure.
  • the second spring 56 biases the second on-off valve 52 (corresponding to the on-off valve) in a direction to approach the second passage 27.
  • the second on-off valve 52 shuts off the second passage 27 and the low pressure chamber 57 (that is, the low pressure passage 58).
  • the second on-off valve 52 does not have a portion that slides with the second passage 27 (second member 22), and opens and closes the open end of the second passage 27.
  • the second on-off valve 52 shuts off the second passage 27 and the low pressure chamber 57, fuel does not leak between the second passage 27 and the low pressure chamber 57. That is, the second on-off valve 52 has a leakless structure.
  • the fuel pressure in the second control chamber 36, the first control chamber 46, the intermediate chamber 26, the first passage 25, and the second passage 27 is It is well balanced with high pressure.
  • the driven valve 41 is biased by a spring 45 and abuts on the second member 22.
  • the first solenoid 53 is energized and driven to separate the first on-off valve 51 from the second member 22 (the open end of the first passage 25) against the biasing force of the first spring 55.
  • the first on-off valve 51 causes the first passage 25 and the low pressure chamber 57 to communicate with each other.
  • the fuel in the intermediate chamber 26 is discharged to the outside of the fuel injection valve 20 through the first passage 25, the low pressure chamber 57, and the low pressure passage 58.
  • the second solenoid 54 is energized and driven to move the second on-off valve 52 away from the second member 22 (the open end of the second passage 27) against the biasing force of the second spring 56.
  • the second on-off valve 52 causes the second passage 27 and the low pressure chamber 57 to communicate with each other.
  • the fuel in the first control chamber 46 is discharged to the outside of the fuel injection valve 20 through the second passage 27, the low pressure chamber 57 and the low pressure passage 58. Ru.
  • the first passage 25 communicates with the low pressure chamber 57 (the first on-off valve 51 opens) and the second passage 27 communicates with the low pressure chamber 57 (the second on-off valve 52 opens)
  • the first passage The fuel pressure in the first control chamber 46 decreases more quickly than in the state where the second low pressure chamber 57 communicates with the second low pressure chamber 57 and the second low pressure chamber 57 is closed (the second on-off valve 52 is closed).
  • the lift speed (rising speed) of the needle valve 31 in the state where the first on-off valve 51 is opened and the second on-off valve 52 is opened is the state where the first on-off valve 51 is opened and the second on-off valve 52 is closed.
  • the increase rate (slope) of the injection rate in the state where the first on-off valve 51 is open and the second on-off valve 52 is open is the injection rate in the state where the first on-off valve 51 is open and the second on-off valve 52 is closed. It becomes larger than the rising speed (slope) of
  • the energization drive of the first solenoid 53 is stopped, and the first on-off valve 51 abuts on the second member 22 by the biasing force of the first spring 55.
  • the first passage 25 and the low pressure chamber 57 are shut off by the first on-off valve 51.
  • the first control chamber 46 and the intermediate chamber 26 communicate with each other without via the third passage 42 of the driven valve 41, and the second high pressure passage 14 and the first control chamber 46 communicate with each other.
  • the fuel pressure in the first control chamber 46 is increased, and the fuel flows from the first control chamber 46 into the second control chamber 36 via the connection passage 47.
  • the needle valve 31 starts to descend (move in the direction of the injection hole 34), and the needle valve 31 shifts to the valve closing operation.
  • the inside of the first control chamber 46 is more than the state where the first on-off valve 51 is closed and the second on-off valve 52 is open.
  • the decrease rate (tilt) of the injection rate in the state where the first on-off valve 51 is closed and the second on-off valve 52 is closed is the injection rate in the state where the first on-off valve 51 is closed and the second on-off valve 52 is open.
  • the ECU (Electronic Control Unit) 90 is a microcomputer including a CPU, a ROM, a RAM, a drive circuit, an input / output interface, and the like.
  • the ECU 90 (corresponding to a drive unit) electrically drives the first solenoid 53 and the second solenoid 54 independently of each other. That is, the ECU 90 separates the communication and blocking between the first passage 25 and the low pressure chamber 57 by the first on-off valve 51 and the communication and blocking between the second passage 27 and the low pressure chamber 57 by the second on-off valve 52 To control.
  • the first on-off valve 51 shifts to a state in which the first on-off valve 51 is opened as shown in FIG. 2 from the state in which the first on-off valve 51 and the second on-off valve 52 are closed,
  • the fuel is discharged to the outside of the fuel injection valve 20 through the chamber 57 and the low pressure passage 58.
  • the intermediate chamber 26 is in communication with the first control chamber 46 via the third passage 42. Since the third passage 42 has the first throttle 42a, a pressure difference is generated in the fuel before and after the first throttle 42a. For this reason, the fuel pressure inside the intermediate chamber 26 becomes low, and the fuel inside the first control chamber 46 becomes medium pressure.
  • the driven valve 41 is attracted to the intermediate chamber 26, and the driven valve 41 shuts off the annular chamber 14b (that is, the second high pressure passage 14) and the first control chamber 46.
  • the first throttle is such that the driven valve 41 shuts off the annular chamber 14b and the first control chamber 46.
  • a flow passage area 42a, an opening area of the intermediate chamber 26 to the third member 23 (first control chamber 46) side, an opening area of the annular chamber 14b to the third member 23 (first control chamber 46) side, and a spring A biasing force of 45 is set. That is, when the first passage 25 and the low pressure chamber 57 are communicated by the first on-off valve 51, the driven valve 41 causes the first control chamber 46 and the intermediate chamber 26 to communicate with each other via the third passage 42.
  • the restriction of the flow rate of fuel by the first throttle 42 a, the exposed area of the driven valve 41 to the intermediate chamber 26, the exposed area of the driven valve 41 to the first high pressure passage 13, and the setting of the biasing force by the spring 45 It is realized on the basis of
  • FIG. 3 is a sectional view taken along line III-III of FIG. As shown in the figure, in the state where the driven valve 41 shuts off the annular chamber 14b and the first control chamber 46, the seal region where the driven valve 41 seals the intermediate chamber 26 and the annular chamber 14b to each other is a region 22a, 22b. It is.
  • FIG. 4 is a partially enlarged view showing the vicinity of the driven valve 441 of the comparative example.
  • the parts corresponding to the parts in FIG. 1 are given the same reference numerals as the parts in FIG. 1 plus 400.
  • an annular chamber 427 b of the second passage 427 communicates with the control chamber 446 through the fourth passage 443 formed in the driven valve 44 between the first passage 425 and the second high pressure passage 414. doing. That is, in this comparative example, the third passage 442 and the third passage 442 in which the first passage 425 and the second passage 427 are formed in the driven valve 441 in a state where the driven valve 441 shuts off the second high pressure passage 414 and the control chamber 446. It communicates with the control chamber 446 via the four passages 443 respectively.
  • FIG. 5 is a cross-sectional view taken along line VV of FIG. As shown in the figure, in the state where the driven valve 441 shuts off the annular chamber 414b and the control chamber 446, the seal region where the driven valve 441 seals the intermediate chamber 426, the annular chamber 427b and the annular chamber 414b to each other 422a, 422b, and 422c.
  • the comparative example requires the regions 422a, 422b and 422c as the seal region in the driven valve 441.
  • the present embodiment only requires the areas 22a and 22b as the seal area in the driven valve 41. For this reason, in the present embodiment, the number of seal areas required in the driven valve 41 can be reduced, and the configuration in the vicinity of the driven valve 41 can be simplified.
  • FIG. 6 is a partially enlarged view showing the vicinity of a driven valve 541 of another comparative example.
  • the part which corresponds to each part of FIG. 1 is given the code which added 500 to the code of each part of FIG.
  • the first passage 525 and the second passage 527 communicate with the intermediate chamber 526
  • the intermediate chamber 526 communicates with the control chamber 546 via a third passage 542 formed in the driven valve 541. That is, in this comparative example, in the second member 522, the two passages 525 and 527 need to be communicated with the intermediate chamber 526 opened to the driven valve 541 side (the control chamber 546 side).
  • the needle valve 31 is rapidly lifted and the third member 23 It repeatedly collides with (or with a stopper), and the behavior of the needle valve 31 becomes unstable.
  • the speed at which the fuel pressure in the second control chamber 36 decreases is too low, the speed (responsiveness) at which the needle valve 31 lifts may be too low.
  • connection passage 47 has a fourth throttle 47a that limits the flow rate of fuel.
  • the flow rate of the fuel flowing out of the second control chamber 36 is limited by the fourth throttle 47 a, and the speed at which the fuel pressure in the second control chamber 36 decreases is appropriately set.
  • the first on-off valve 51 is opened, the second on-off valve 52 is opened, and the second high pressure passage 14 and the first control chamber 46 are shut off by the driven valve 41 and the high pressure chamber 33 is injected by the needle valve 31.
  • the flow rate of fuel through fourth throttle 47a is set larger than the sum of the flow rate of fuel through first throttle 42a and the flow rate of fuel through second throttle 27a. ing.
  • the flow rate of the fuel flowing into the first control chamber 46 via the connection passage 47 is larger than the flow rate of the fuel flowing out of the first control chamber 46 via the third passage 42 and the second passage 27. Therefore, it can suppress that the fuel pressure inside the 1st control chamber 46 falls too much, and it can suppress that the differential pressure which arose in the fuel before and behind the 1st throttle 42a reduces. Further, the fourth throttle 47 a suppresses the transmission of the pulsation of the fuel pressure between the first control chamber 46 and the second control chamber 36.
  • the full lift limit is set as the lift amount when the needle valve 31 collides with the third member 23 (or the stopper), and the lift amount of the needle valve 31 is controlled to be smaller than the full lift limit. Do. In detail, when the lift amount of the needle valve 31 comes immediately before the full lift limit, the needle valve 31 is shifted to the closing operation so as to reduce the lift amount. At this time, the amount of fuel that can be injected by the fuel injection valve 20 becomes maximum.
  • FIG. 7 is a graph showing the relationship between the lift amount of the needle valve 31 and the injection rate.
  • the ECU 90 controls to raise (increase) the injection rate at high speed at the start of injection, and to decrease (decrease) the injection rate at high speed at the end of injection, and maximize the amount of fuel to be injected. doing. Specifically, the ECU 90 opens the first on-off valve 51 and the second on-off valve 52 to start fuel injection, and when the injection rate becomes maximum (the injection hole 34 is fully open), the second on-off valve 52 Is closed. Thereafter, immediately before the lift amount of the needle valve 31 reaches the full lift limit, the first on-off valve 51 is closed and the second on-off valve 52 is opened.
  • the second on-off valve 52 is closed.
  • the amount of fuel to be injected is the area of the portion below the graph of the injection rate (the value obtained by integrating the graph of the injection rate).
  • FIG. 8 is a graph showing the relationship between the lift amount and the injection rate of the needle valve of the comparative example.
  • the injection rate is raised at high speed at the start of injection, and the injection rate is lowered at high speed at the end of injection, and the amount of fuel to be injected is controlled to be maximum.
  • the speed at which the needle valve lifts and the speed at which it descends can not be changed. As a result, the time taken for the lift amount of the needle valve to reach the full lift limit is shortened, and the amount of fuel injected is reduced.
  • FIG. 9 is a schematic view showing a pressure reducing operation in which the fuel pressure in the common rail 11 is reduced by the second on-off valve 52 without the fuel injection valve 20 injecting fuel.
  • the first on-off valve 51 and the second on-off valve 52 are closed, the inside of the second control chamber 36, the first control chamber 46, the intermediate chamber 26, the first passage 25, and the second passage 27
  • the fuel pressure of each is balanced at high pressure.
  • the driven valve 41 is biased by a spring 45 and abuts on the second member 22.
  • the ECU 90 opens the second on-off valve 52 from this state.
  • the fuel in the first control chamber 46 is discharged through the second passage 27. Since the driven valve 41 is not attracted to the intermediate chamber 26, when the fuel pressure in the first control chamber 46 decreases, the fuel pressure in the second high pressure passage 14 separates the driven valve 41 from the second member 22.
  • the flow rate of fuel via the third throttle 14a is set larger than the flow rate of fuel via the second throttle 27a. ing. Therefore, the amount of fuel flowing from the second high pressure passage 14 into the first control chamber 46 is larger than the amount of fuel discharged from the inside of the first control chamber 46. Therefore, the fuel pressure inside the first control chamber 46 does not decrease, and the state in which the high pressure chamber 33 and the injection hole 34 are shut off by the needle valve 31 is maintained. Then, fuel flows from the common rail 11 into the first control chamber 46 via the first high pressure passage 13 and the second high pressure passage 14, so the fuel pressure in the common rail 11 is reduced. That is, the fuel pressure in the common rail 11 is reduced while the fuel injection valve 20 does not inject the fuel.
  • FIG. 10 is a graph showing injection rate patterns at high speed start-up and high speed stop.
  • both the first on-off valve 51 and the second on-off valve 52 are closed, and the high-pressure chamber 33 and the injection hole 34 are shut off by the needle valve 31.
  • the fuel in the first control chamber 46 passes through the third passage 42, the first passage 25 and the second passage 27. Discharged.
  • a differential pressure is generated in the fuel before and after the first throttle 42 a, and the driven valve 41 is attracted to the intermediate chamber 26.
  • the fuel pressure in the first control chamber 46 is reduced at high speed, and the needle valve 31 is lifted at high speed. For this reason, as shown in FIG. 10, the injection rate is raised at high speed.
  • FIG. 15 is a graph showing injection rate patterns at low speed startup and high speed shutdown.
  • the fuel in the first control chamber 46 passes through the third passage 42 and the first passage 25. Discharged.
  • a differential pressure is generated in the fuel before and after the first throttle 42 a, and the driven valve 41 is attracted to the intermediate chamber 26.
  • the fuel pressure in the first control chamber 46 decreases at low speed, and the needle valve 31 lifts at low speed. Therefore, as shown in FIG. 15, the injection rate is raised at a low speed. After the injection rate is maximized, the operation is similar to that of the high-speed fall shown in FIG.
  • FIG. 17 is a graph showing injection rate patterns at high speed startup and low speed shutdown. The operation at high-speed start-up is the same as the operation at high-speed start-up shown in FIG.
  • the second high pressure passage 14 and the first control chamber 46 communicate with each other, and the fuel pressure in the first control chamber 46 rises at a low speed.
  • the needle valve 31 starts to descend and closes. Transition to operation. Since the fuel pressure in the first control chamber 46 rises at a low speed, the injection rate falls at a low speed as shown in FIG.
  • FIG. 20 is a graph showing injection rate patterns at low speed startup and low speed shutdown.
  • the operation at low speed startup is similar to the operation at low speed startup shown in FIG.
  • the operation at the time of low speed fall is the same as the operation at the time of low speed fall shown in FIG.
  • FIG. 21 is a graph showing an injection rate pattern when changing from low speed startup to high speed startup.
  • the operation at low speed startup is similar to the operation at low speed startup shown in FIG.
  • the needle valve 31 is being lifted (moving in the direction in which the high pressure chamber 33 and the injection hole 34 communicate with each other)
  • the ECU 90 shifts to an operation at high speed startup. That is, as shown in FIG. 16, from the state where the first on-off valve 51 is opened and the second on-off valve 52 is closed, both the first on-off valve 51 and the second on-off valve 52 are opened as shown in FIG. Transition to the state.
  • the subsequent operation at high speed startup is similar to the operation at high speed startup shown in FIG.
  • FIG. 22 is a graph showing an injection rate pattern at the time of change from high speed startup to low speed startup.
  • the operation at high-speed start-up is the same as the operation at high-speed start-up shown in FIG.
  • the ECU 90 shifts to an operation at low speed startup. That is, as shown in FIG. 12, the first on-off valve 51 is opened and the second on-off valve 52 is closed as shown in FIG. 16 from the state where both the first on-off valve 51 and the second on-off valve 52 are open. Transition to the state.
  • the subsequent low speed startup operation is the same as the low speed startup operation shown in FIG.
  • FIG. 23 is a graph showing an injection rate pattern at the time of change from high speed fall to low speed fall. The description of the operation from the start up to the maximum injection rate will be omitted.
  • the subsequent operation at the time of high-speed fall is similar to the operation at the high-speed fall shown in FIG.
  • the needle valve 31 is moving downward (moving in the direction to shut off the high pressure chamber 33 and the injection hole 34)
  • the ECU 90 shifts to the operation at the time of low speed falling. That is, as shown in FIG. 14, from the state where both the first on-off valve 51 and the second on-off valve 52 are closed, as shown in FIG. 19, the first on-off valve 51 is closed and the second on-off valve 52 is opened. Transition to the state.
  • the subsequent operation at the time of low-speed ramp-down is the same as the operation at the low-speed ramp-up shown in FIG.
  • FIG. 24 is a graph showing an injection rate pattern when changing from low speed fall to high speed fall. The description of the operation from the start up to the maximum injection rate will be omitted.
  • the subsequent low speed falling operation is the same as the low speed falling operation shown in FIG.
  • the ECU 90 shifts to an operation at the time of high speed falling. That is, as shown in FIG. 19, from the state where the first on-off valve 51 is closed and the second on-off valve 52 is opened, both the first on-off valve 51 and the second on-off valve 52 are closed as shown in FIG. Transition to the state.
  • the operation at the time of the subsequent high-speed shutdown is the same as the operation at the high-speed startup shown in FIG.
  • the ECU 90 controls the open / close state of the on-off valves 51 and 52 and hence the inclination of the injection rate of fuel by the fuel injection valve 20 based on the operating state of the engine on which the fuel injection valve 20 is mounted and the fuel pressure in the common rail 11. .
  • the operating state of the engine for example, the load of the engine, the rotational speed of the engine, the air-fuel ratio, etc. can be adopted.
  • the ECU 90 may correct the timing of switching the open / close states of the on-off valves 51 and 52 according to the individual difference of the fuel injection valve 20 and the responsiveness of the needle valve 31 caused by the temperature.
  • the ECU 90 can switch the open / close states of the on-off valves 51, 52 between the state shown in FIG. 12 and the state shown in FIG. 16 plural times or continuously during the lift of the needle valve 31. . In that case, while the needle valve 31 is being lifted, the rate of increase (inclination) of the fuel injection rate can be changed in multiple stages or continuously.
  • the ECU 90 can switch the open / close state of the on / off valves 51 and 52 between the state shown in FIG. 14 and the state shown in FIG. 19 multiple times or continuously while the needle valve 31 is lowered. In that case, the lowering speed (slope) of the fuel injection rate can be changed in multiple stages or continuously while the needle valve 31 is moving downward.
  • FIG. 25 is a time chart showing the operation at the time of low speed rise and at high speed fall.
  • the fuel pressure in the first control chamber 46 and the fuel pressure in the second control chamber 36 are equal.
  • the fuel injection valve 20 can reduce the fuel leakage from the high pressure side to the low pressure side of the fuel passage to 0 in a state where the fuel is not being injected, thereby suppressing the energy to supply the fuel to the common rail 11 be able to.
  • the fuel pressure in the intermediate chamber 26 and the control chambers 46 and 36 decreases.
  • the third passage 42 has the first throttle 42 a
  • the fuel pressure in the intermediate chamber 26 decreases at a speed higher than the fuel pressure in the control chambers 46 and 36.
  • the fuel flowing from the high pressure passages 13 and 14 into the first control chamber 46 and the second control chamber 36 is zero. Therefore, even when the flow rate of fuel from the first passage 25 to the low pressure chamber 57 is small, the fuel pressure in the control chambers 46 and 36 can be reduced at a necessary speed, and the needle valve 31 is required. It is possible to lift with quick response.
  • the needle valve 31 starts to lift. Since the fuel in the first control chamber 46 is discharged through the first passage 25 and not from the second passage 27, the fuel pressure in the control chambers 46, 36 decreases at a low speed. Here, the amount of fuel discharged from the second control chamber 36 and the amount of reduction of the volume of the second control chamber 36 due to the lift of the needle valve 31 are balanced, and the fuel pressure in the second control chamber 36 is constant. Become. That is, since the volume of the second control chamber 36 decreases at low speed, the needle valve 31 is lifted at low speed, and the injection rate is raised at low speed. Also at this time, the fuel flowing into the first control chamber 46 and the second control chamber 36 from the high pressure passages 13 and 14 is zero.
  • the needle valve 31 starts to descend. Since fuel in the first control chamber 46 is not discharged from the first passage 25 and not discharged from the second passage 27, the fuel pressure in the control chambers 46, 36 rises at high speed. At this time, the leak of fuel from the first passage 25 to the low pressure chamber 57 is zero, and the leak of fuel from the second passage 27 to the low pressure chamber 57 is zero.
  • the amount of fuel flowing into the second control chamber 36 and the amount of increase in volume of the second control chamber 36 due to the lowering of the needle valve 31 are balanced, and the fuel pressure in the second control chamber 36 becomes constant. .
  • the needle valve 31 is lowered at high speed, and the injection rate is lowered at high speed. Also at this time, the fuel leakage from the first passage 25 to the low pressure chamber 57 is zero, and the fuel leakage from the second passage 27 to the low pressure chamber 57 is zero.
  • the high pressure chamber 33 and the injection hole 34 are shut off by the needle valve 31, and the fuel pressure in the control chambers 46 and 36 is increased. Thereafter, the fuel pressure in the first control chamber 46 and the fuel pressure in the intermediate chamber 26 are balanced at high pressure, and the follower valve 41 is urged by the spring 45 to abut the follower valve 41 on the second member 22 .
  • FIG. 26 is a time chart showing operations at the time of high-speed start-up and low-speed fall-off.
  • the first on-off valve 51 and the second on-off valve 52 are both closed, the lift amount of the driven valve 41 is 0, the fuel pressure in the control chambers 46 and 36 and the intermediate chamber 26 is high, and the needle valve The lift amount and the injection rate of 31 are zero.
  • the leak of fuel from the first passage 25 to the low pressure chamber 57 is zero, and the leak of fuel from the second passage 27 to the low pressure chamber 57 is zero.
  • the needle valve 31 starts to lift. Since the fuel in the first control chamber 46 is discharged through the first passage 25 and the second passage 27, the fuel pressure in the control chambers 46, 36 decreases at high speed. That is, since the volume of the second control chamber 36 decreases at high speed, the needle valve 31 is lifted at high speed, and the injection rate is raised at high speed. Also at this time, the fuel flowing into the first control chamber 46 and the second control chamber 36 from the high pressure passages 13 and 14 is zero.
  • the second on-off valve 52 is maintained in the open state, and when the first on-off valve 51 is closed, the fuel pressure in the intermediate chamber 26 rises.
  • the driven valve 41 separates from the second member 22. Therefore, high pressure fuel flows from the second high pressure passage 14 into the first control chamber 46.
  • the needle valve 31 starts to descend. Since the fuel in the first control chamber 46 is not discharged from the first passage 25 and is discharged from the second passage 27, the fuel pressure in the control chambers 46 and 36 rises at a low speed. That is, since the volume of the second control chamber 36 increases at low speed, the needle valve 31 is lowered at low speed, and the injection rate is lowered at low speed.
  • the high pressure chamber 33 and the injection hole 34 are shut off by the needle valve 31, and the fuel pressure in the control chambers 46 and 36 is increased. Thereafter, the second on-off valve 52 is closed, and the fuel pressure in the first control chamber 46 and the fuel pressure in the intermediate chamber 26 are balanced at a high pressure. Then, the driven valve 41 is biased by the spring 45, and the driven valve 41 abuts on the second member 22. At this time, the leak of fuel from the first passage 25 to the low pressure chamber 57 is zero, and the leak of fuel from the second passage 27 to the low pressure chamber 57 is zero.
  • FIG. 27 is a time chart showing an operation at the time of change from low speed startup to high speed startup. From time t31 to t33, the operation is similar to that from time t11 to t13 in FIG.
  • the second on-off valve 52 is opened.
  • the fuel in the first control chamber 46 is discharged through the first passage 25 and the second passage 27, so the fuel pressure in the control chambers 46, 36 decreases at high speed. That is, since the volume of the second control chamber 36 decreases at high speed, the needle valve 31 is lifted at high speed, and the injection rate is raised at high speed.
  • the injection rate is changed from low speed startup to high speed startup. At this time, the fuel flowing from the high pressure passages 13 and 14 into the first control chamber 46 and the second control chamber 36 is zero.
  • FIG. 28 is a time chart showing an operation at the time of change from high-speed fall to low-speed fall. Until time t45, the operation is similar to that until time t15 in FIG.
  • the second on-off valve 52 is opened while the needle valve 31 is descending (the injection rate is decreasing).
  • the fuel in the first control chamber 46 is discharged through the second passage 27, so the fuel pressure in the control chambers 46, 36 rises at a low speed. That is, since the volume of the second control chamber 36 increases at low speed, the needle valve 31 is lowered at low speed, and the injection rate is lowered at low speed. As a result, while the needle valve 31 is moving downward, the injection rate is changed from high speed falling to low speed falling.
  • the speed at which the fuel pressure in the first control chamber 46 decreases is increased. Therefore, the speed at which the needle valve 31 lifts can be increased, and the inclination of the fuel injection rate can be increased. Therefore, in a state where the first passage 25 and the low pressure passage 58 are communicated with each other by the first on-off valve 51, the communication and blocking of the second passage 27 and the low pressure passage 58 by the second on-off valve 52 are controlled. The slope of the injection rate can be controlled.
  • the fuel injection valve 20 has a configuration in which the first passage 25 and the second passage 27 communicate with the first control chamber 46 respectively through two passages formed in the driven valve 41, or the first passage 25 and the second It is not necessary to adopt a configuration in which the passage 27 communicates with the intermediate chamber 26 and the intermediate chamber 26 communicates with the first control chamber 46 via one passage formed in the driven valve 41. Therefore, in the fuel injection valve 20 capable of controlling the inclination of the injection rate of the fuel, the configuration in the vicinity of the driven valve 41 can be simplified.
  • the fuel injection valve 20 includes a first on-off valve 51 for communicating and blocking the first passage 25 and the low pressure passage 58, and a second on-off valve 52 for communicating and blocking the second passage 27 and the low pressure passage 58. ing. Therefore, the communication and blocking between the first passage 25 and the low pressure passage 58 and the communication and blocking between the second passage 27 and the low pressure passage 58 can be controlled independently of each other. In a state where the first on-off valve 51 shuts off the first passage 25 and the low pressure chamber 57, fuel does not leak between the first passage 25 and the low pressure chamber 57. In the state where the second on-off valve 52 shuts off the second passage 27 and the low pressure chamber 57, fuel does not leak between the second passage 27 and the low pressure chamber 57. Therefore, the fuel injection valve 20 can reduce the fuel leakage from the high pressure side to the low pressure side of the fuel passage to zero in a state where the fuel is not being injected, thereby suppressing the energy to supply the fuel to the common rail 11 be able to.
  • the first on-off valve 51 and the second on-off valve 52 With the first on-off valve 51 and the second on-off valve 52 closed, the first on-off valve 51 is closed and the second on-off valve 52 is opened. And the second high pressure passage 14 and the first control chamber 46 are communicated by the driven valve 41. Therefore, the fuel in the second high pressure passage 14 can be discharged through the first control chamber 46, the second passage 27, and the low pressure passage 58 in a state where fuel injection is not performed by the fuel injection valve 20. . Therefore, the function of the pressure reducing valve for reducing the fuel pressure in the second high pressure passage 14 and hence the fuel pressure in the common rail 11 for supplying the fuel to the second high pressure passage 14 can be realized by the second on-off valve 52 it can.
  • the second high pressure passage 14 has the third throttle 14a for limiting the flow rate of fuel, and in the state where the first on-off valve 51 is closed and the second on-off valve 52 is opened, the third high-pressure passage 14
  • the flow rate of the fuel is set larger than the flow rate of the fuel through the second throttle 27a.
  • the flow rate of the fuel flowing from the second high pressure passage 14 into the first control chamber 46 via the third throttle 14a is the flow rate of the fuel flowing out from the first control chamber 46 via the second throttle 27a. It becomes bigger than. Therefore, even if the second passage 27 and the first control chamber 46 are in communication with each other by the driven valve 41, the fuel pressure in the first control chamber 46 does not decrease, and the high pressure chamber 33 is maintained by the needle valve 31. And the injection hole 34 can be maintained in a closed state.
  • the first control chamber 46 and the intermediate chamber 26 are communicated by the driven valve 41 without the intervention of the third passage 42. Then, in a state where the first control chamber 46 and the intermediate chamber 26 communicate with each other without the third passage 42 by the driven valve 41, the second high pressure passage 14 and the first control chamber 46 are communicated by the driven valve 41. . Therefore, the fuel pressure in the first control chamber 46 is increased, and the needle valve 31 can shift the operation to shut off the high pressure chamber 33 and the injection hole 34.
  • the first passage 25 and the low pressure passage 58 are in communication, and the second passage 27 and the low pressure passage 58 are in communication, and the first passage 25 and the low pressure passage 58 are in communication
  • the state in which the second passage 27 and the low pressure passage 58 are shut off can be switched.
  • the speed at which the fuel pressure in the first control chamber 46 decreases can be changed, and the speed at which the needle valve 31 lifts, and hence the fuel injection rate.
  • the inclination can be changed.
  • the fuel flowing from the high pressure passages 13 and 14 into the first control chamber 46 and the second control chamber 36 is zero. Therefore, even when the flow rate of fuel from the first passage 25 and the second passage 27 to the low pressure chamber 57 is small, the fuel pressure in the control chambers 46 and 36 can be reduced at a necessary speed.
  • the needle valve 31 can be lifted with the required responsiveness.
  • the first passage 25 communicates with the low pressure passage 58 and the second passage 27 communicates with the low pressure passage 58 while the needle valve 31 moves in the direction to connect the high pressure chamber 33 and the injection hole 34
  • the first passage 25 and the low pressure passage 58 are in communication with each other, and the second passage 27 and the low pressure passage 58 are disconnected. According to such a configuration, while the needle valve 31 is being lifted, it is possible to flexibly change the speed at which the needle valve 31 is lifted, and hence the inclination of the fuel injection rate.
  • the main body of the fuel injection valve 20 is formed with a first control chamber 46 in which the driven valve 41 is disposed and a second control chamber 36 in which the needle valve 31 is exposed.
  • a connection passage 47 is formed, which is a passage connecting the first control chamber 46 and the second control chamber 36, and has a fourth throttle 47a for limiting the flow rate of the fuel.
  • the flow rate of the fuel flowing out of the second control chamber 36 can be limited by the fourth throttle 47a of the connection passage 47, and the speed at which the fuel pressure in the second control chamber 36 decreases can be appropriately adjusted. It can be set.
  • it can be suppressed that the pulsation of the fuel pressure is transmitted between the first control chamber 46 and the second control chamber 36. Therefore, it is possible to suppress that the pulsation of the fuel pressure adversely affects the behavior of the driven valve 41 and the needle valve 31.
  • the flow rate of fuel flowing into the first control chamber 46 via the connection passage 47 is greater than the flow rate of fuel flowing out of the first control chamber 46 via the third passage 42 and the second passage 27. For this reason, it can suppress that the fuel pressure inside the 1st control chamber 46 falls too much, and it can suppress that the differential pressure which arose in the fuel before and behind the 1st throttle 42a reduces. Therefore, the driven valve 41 can be maintained in a state of being attracted to the intermediate chamber 26 by the pressure difference generated in the fuel before and after the first throttle 42a.
  • a first low pressure chamber 57A, a connection passage 59, a second low pressure chamber 57B, and a low pressure passage 58 are formed in the first member 121.
  • the surface of the first low pressure chamber 57A on the second member 22 side is open. The periphery of the opening is sealed between the first member 21 and the second member 22.
  • the first low pressure chamber 57A and the second low pressure chamber 57B are connected by a connection passage 59.
  • the low pressure passage 58 is connected to the second low pressure chamber 57B.
  • the fuel injection valve 120 of the present embodiment includes only the on-off valve 151 instead of the first on-off valve 51 and the second on-off valve 52 of the first embodiment.
  • the on-off valve 151 is biased by a spring 155 in a direction approaching the second low pressure chamber 57B.
  • An actuator 153 for continuously controlling the lift amount of the on-off valve 151 is disposed in the second low pressure chamber 57B.
  • the actuator 153 includes, for example, an expansion and contraction mechanism configured of a piezoelectric element (piezoelectric element).
  • the on / off valve 151 blocks the first low pressure chamber 57A (the first passage 25 and the second passage 27) from the connection passage 59 (the low pressure passage 58).
  • the on-off valve 151 does not have a portion that slides with the connection passage 59 (first member 121), and opens and closes the open end of the connection passage 59.
  • the drive state of the actuator 153 is controlled by the ECU 90 (corresponding to a drive unit).
  • FIG. 30 is a schematic view showing the state of the on-off valve 151 at the time of high speed startup.
  • the first low pressure chamber 57A and the second passage 27 are in communication with each other by the on-off valve 151, and the first low pressure chamber 57A and the connection passage 59 are in communication. Since the fuel in the first control chamber 46 is discharged through the first passage 25 and the second passage 27, the fuel pressure in the control chambers 46, 36 decreases at high speed. That is, since the volume of the second control chamber 36 decreases at high speed, the needle valve 31 is lifted at high speed, and the injection rate is raised at high speed. At this time, the fuel flowing from the high pressure passages 13 and 14 into the first control chamber 46 and the second control chamber 36 is zero. Therefore, even when the flow rate of fuel from the first passage 25 and the second passage 27 to the first low pressure chamber 57A is small, the fuel pressure in the control chambers 46 and 36 can be reduced at high speed.
  • the needle valve 31 can be lifted with high responsiveness.
  • FIG. 31 is a schematic view showing the state of the on-off valve 151 at low speed startup.
  • the first low pressure chamber 57A and the second passage 27 are shut off by the on-off valve 151, and the first low pressure chamber 57A and the connection passage 59 are in communication.
  • the fuel in the first control chamber 46 is discharged through the first passage 25 and not discharged through the second passage 27, the fuel pressure in the control chambers 46, 36 decreases at a low speed. That is, since the volume of the second control chamber 36 decreases at low speed, the needle valve 31 is lifted at low speed, and the injection rate is raised at low speed.
  • the fuel flowing from the high pressure passages 13 and 14 into the first control chamber 46 and the second control chamber 36 is zero. Therefore, even when the flow rate of fuel from the first passage 25 to the first low pressure chamber 57A is small, the fuel pressure in the control chambers 46 and 36 can be reduced at a necessary speed. Can be lifted with the required responsiveness.
  • the ECU 90 determines the lift amount (open / close state) of the on-off valve 151 and hence the inclination of the fuel injection rate by the fuel injection valve 120 based on the operating state of the engine in which the fuel injection valve 120 is mounted and the fuel pressure in the common rail 11. It is good to control. Further, the ECU 90 may switch the open / close state of the on-off valve 151 between the state shown in FIG. 30 and the state shown in FIG. 31 plural times or continuously while the needle valve 31 is being lifted or lowered. it can.
  • the first low pressure chamber 57A (the first passage 25 and the second passage 27) and the connection passage 59 (the low pressure passage 58) are shut off by the on-off valve 151, thereby shifting the needle valve 31 to the closing operation.
  • the fuel leak from the first low pressure chamber 57A to the connection passage 59 is zero. Therefore, the fuel flowing into the first control chamber 46 and the second control chamber 36 from the second high pressure passage 14 can efficiently increase the fuel pressure in the second control chamber 36.
  • the spring 45 for biasing the driven valve 41 toward the second member 22 can be omitted. Even in such a case, the fuel pressure in the intermediate chamber 26 is reduced by discharging the fuel in the intermediate chamber 26 via the first passage 25, and the driven valve 41 is attracted to the intermediate chamber 26. Can. Then, in a state where the driven valve 41 is drawn to the intermediate chamber 26, a pressure difference is generated in the fuel before and after the first throttle 42 a in the driven valve 41, and the state where the driven valve 41 is drawn to the intermediate chamber 26 by this pressure difference. Can be maintained.
  • the first control chamber 46 may be formed in the second member 122, and the driven valve 41 may be disposed in the first control chamber 46.
  • the second passage 127 and the first control chamber 46 can also be connected inside the second member 122. Also with such a configuration, the same function and effect as those of the first embodiment can be obtained.
  • the second passage 227 may be formed between the second member 22 and the third member 223, and the second passage 227 may be connected to the second control chamber 36. According to such a configuration, by opening the second on-off valve 52, the fuel pressure in the second control chamber 36 can be reduced with high responsiveness. In addition, the same operation and effect as those of the first embodiment can be achieved.
  • the needle valve 131 can also be provided with a stopper 131a for limiting (adjusting) the maximum lift amount of the needle valve 131.
  • a protrusion as a stopper 131a is provided at the end opposite to the injection hole 34 of the needle valve 131. Then, when the lift amount of the needle valve 131 becomes large, the stopper 131a abuts on the third member 23.
  • a flange as a stopper 231a may be provided in the middle of the needle valve 231. Then, when the lift amount of the needle valve 231 becomes large, the stopper 231 a abuts on the cylinder 35. According to these configurations, it is possible to limit the maximum lift amount while reducing the volume of the second control chamber 36 to improve the response of the needle valves 131 and 231.
  • FIG. 36 is a partial cross-sectional view showing a modification of the first embodiment
  • FIG. 37 is an enlarged cross-sectional view showing a part of FIG.
  • the position of the first solenoid 53 and the position of the second solenoid 54 are different in the longitudinal direction (axial direction) of the fuel injection valve 20 (the needle valve 31).
  • the distance from the needle valve 31 to the first solenoid 53 is shorter than the distance from the needle valve 31 to the second solenoid 54. Therefore, compared to the configuration in which the first solenoid 53 and the second solenoid 54 are arranged side by side, it is possible to make the fuel injection valve 20 thinner (smaller in diameter).
  • the length of the first on-off valve 51 is shorter than the length of the second on-off valve 52.
  • a low pressure chamber 57 extending in the longitudinal direction of the second on-off valve 52 (fuel injection valve 20) is formed on the outer periphery of the second on-off valve 52. That is, in the inside of the first member 21, the space in which the second on-off valve 52 is disposed can be used as the low pressure chamber 57.
  • the second solenoid 54 is provided at the end of the main body (first to fourth members 21 to 24) of the fuel injection valve 20 opposite to the injection hole 34.
  • the second solenoid 54 is larger than the first solenoid 53.
  • the driving force of the second on-off valve 52 by the second solenoid 54 can be made larger than the driving force of the first on-off valve 51 by the first solenoid 53. According to the above configuration, the same function and effect as those of the first embodiment can be obtained.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

L'invention concerne une vanne d'injection de carburant (20) comprenant : une vanne à aiguille (31) pour connecter et déconnecter une chambre haute pression (33) et un trou d'injection (34) ; une vanne entraînée (41) qui est disposée à l'intérieur d'une chambre de commande (46) et dont l'état de levage est commandé sur la base de la pression de carburant à l'intérieur d'une chambre intermédiaire (26) ; et des vannes d'ouverture/fermeture (51, 52) pour connecter et déconnecter un premier passage (25) et un passage basse pression (58) et connecter et déconnecter un deuxième passage (27) et le passage basse pression. La vanne entraînée est pourvue d'un troisième passage (42) s'étendant à travers la vanne entraînée et ayant un premier passage rétréci (42a) qui limite le débit de carburant. La vanne entraînée déconnecte un passage haute pression (14) et la chambre de commande tandis que la chambre de commande et la chambre intermédiaire sont en communication l'une avec l'autre par l'intermédiaire du troisième passage, et la vanne entraînée connecte le passage haute pression et la chambre de commande tandis que la chambre de commande et la chambre intermédiaire sont en communication l'une avec l'autre sans être connectées par l'intermédiaire du troisième passage. Le deuxième passage a un second passage rétréci (27a) pour limiter le débit de carburant et est connecté à la chambre de commande sans être connecté à travers la vanne entraînée.
PCT/JP2018/030875 2017-08-24 2018-08-21 Vanne d'injection de carburant WO2019039480A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE112018004736.9T DE112018004736T5 (de) 2017-08-24 2018-08-21 Kraftstoffeinspritzventil
US16/795,946 US11193464B2 (en) 2017-08-24 2020-02-20 Fuel injection valve

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2017-161662 2017-08-24
JP2017161662 2017-08-24
JP2018-134992 2018-07-18
JP2018134992A JP6706290B2 (ja) 2017-08-24 2018-07-18 燃料噴射弁

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US16/795,946 Continuation US11193464B2 (en) 2017-08-24 2020-02-20 Fuel injection valve

Publications (1)

Publication Number Publication Date
WO2019039480A1 true WO2019039480A1 (fr) 2019-02-28

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10837394B2 (en) 2019-02-05 2020-11-17 Denso Corporation Fuel injection controller
US10883442B2 (en) 2019-01-09 2021-01-05 Denso Corporation Electronic control unit
US10965234B2 (en) 2019-02-06 2021-03-30 Denso Corporation Motor controller and electric power steering device having same
DE102019216069B4 (de) 2018-10-24 2022-06-09 Denso Corporation Kraftstoffinjektionssteuervorrichtung

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030019948A1 (en) * 2001-07-30 2003-01-30 Shinogle Ronald D. Dual solenoid latching actuator and method of using same
JP2007239735A (ja) * 2006-02-08 2007-09-20 Denso Corp 燃料噴射ノズル、燃料噴射装置、およびインジェクタ
US20110048379A1 (en) * 2009-09-02 2011-03-03 Caterpillar Inc. Fluid injector with rate shaping capability
DE102013112751A1 (de) * 2013-11-19 2015-05-21 Denso Corporation Kraftstoffinjektor
JP2017075532A (ja) * 2015-10-13 2017-04-20 株式会社日本自動車部品総合研究所 燃料噴射弁

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030019948A1 (en) * 2001-07-30 2003-01-30 Shinogle Ronald D. Dual solenoid latching actuator and method of using same
JP2007239735A (ja) * 2006-02-08 2007-09-20 Denso Corp 燃料噴射ノズル、燃料噴射装置、およびインジェクタ
US20110048379A1 (en) * 2009-09-02 2011-03-03 Caterpillar Inc. Fluid injector with rate shaping capability
DE102013112751A1 (de) * 2013-11-19 2015-05-21 Denso Corporation Kraftstoffinjektor
JP2017075532A (ja) * 2015-10-13 2017-04-20 株式会社日本自動車部品総合研究所 燃料噴射弁

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102019216069B4 (de) 2018-10-24 2022-06-09 Denso Corporation Kraftstoffinjektionssteuervorrichtung
US10883442B2 (en) 2019-01-09 2021-01-05 Denso Corporation Electronic control unit
US10837394B2 (en) 2019-02-05 2020-11-17 Denso Corporation Fuel injection controller
US10965234B2 (en) 2019-02-06 2021-03-30 Denso Corporation Motor controller and electric power steering device having same

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