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WO2023242980A1 - Dispositif d'injection de carburant - Google Patents

Dispositif d'injection de carburant Download PDF

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Publication number
WO2023242980A1
WO2023242980A1 PCT/JP2022/023898 JP2022023898W WO2023242980A1 WO 2023242980 A1 WO2023242980 A1 WO 2023242980A1 JP 2022023898 W JP2022023898 W JP 2022023898W WO 2023242980 A1 WO2023242980 A1 WO 2023242980A1
Authority
WO
WIPO (PCT)
Prior art keywords
forming member
fuel injection
injection device
movable core
thick
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/JP2022/023898
Other languages
English (en)
Japanese (ja)
Inventor
貴敏 飯塚
威生 三宅
真士 菅谷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Astemo Ltd
Original Assignee
Hitachi Astemo Ltd
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
Application filed by Hitachi Astemo Ltd filed Critical Hitachi Astemo Ltd
Priority to PCT/JP2022/023898 priority Critical patent/WO2023242980A1/fr
Publication of WO2023242980A1 publication Critical patent/WO2023242980A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • 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
    • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
    • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
    • 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type

Definitions

  • the present invention relates to a fuel injection device.
  • Patent Document 1 describes that a load is applied in a direction from the first portion toward the reference position of the valve member to the gap forming member that is assembled to the valve member. Further, it is disclosed that the relative length between the first portion and the second portion is shortened by plastically deforming the gap forming member, so that the prestroke amount is set to a target value.
  • the inner diameter of the magnetic core had to be enlarged to match the maximum outer diameter of the gap forming member.
  • the increase in the inner diameter of the magnetic core may affect the magnetic characteristics of the fuel injection device, causing a problem in that the maximum operating fuel pressure of the fuel injection device may decrease.
  • An object of the present invention is to provide a fuel injection device that is capable of improving the durability and reliability of a gap forming member and suppressing rebound from affecting the characteristics of a fuel injector, in consideration of the above-mentioned problems. There is a particular thing.
  • a fuel injection device includes a magnetic core, a movable core that is attracted to the magnetic core, a valve body having a flange portion on the upstream side of the movable core, and a closed valve body.
  • a gap forming member that forms an axial gap between the collar portion and the movable core in the valve state.
  • the gap forming member has a facing portion that faces the radial direction of the collar portion.
  • a thick portion and a thin portion having an outer diameter smaller than the outer diameter of the thick portion are formed on the outer peripheral surface of the opposing portion. The thick portion is formed on the end surface side of the opposing portion that comes into contact with the movable core.
  • the fuel injection device having the above configuration, it is possible to simultaneously improve the durability and reliability of the gap forming member and suppress the rebound that affects the characteristics of the fuel injector.
  • FIG. 1 is a sectional view showing a fuel injection device according to a first embodiment.
  • FIG. 2 is an enlarged cross-sectional view showing the vicinity of a valve member and an anchor in the fuel injection device according to the first embodiment.
  • FIG. 2 is an enlarged cross-sectional view showing the vicinity of a gap forming member in the fuel injection device according to the first embodiment.
  • FIG. 2 is a cross-sectional view showing a simplified state of the fuel injection device according to the first embodiment before pre-stroke adjustment.
  • FIG. 2 is a partial cross-sectional view showing simplified analysis results of deformation during pre-stroke adjustment in the fuel injection device according to the first embodiment;
  • FIG. 7 is an enlarged cross-sectional view showing the area around a spacer in a fuel injection device according to a second embodiment.
  • FIG. 2 is a partial cross-sectional view showing a state of the fuel injection device according to the embodiment before internal components are inserted.
  • FIG. 1 is a sectional view showing a fuel injection device.
  • the fuel injection device 1 includes a nozzle body 10, a valve body 20, a movable core 30, a magnetic core 40, a coil 50, a housing 70, a connecting portion 80, a filter 90, It is equipped with Further, the fuel injection device 1 includes a first spring 61, a second spring 63, and an adjustment member 62.
  • the nozzle body 10 is formed into a cylindrical shape.
  • a first internal space 130 is formed at a tip portion that is one end of the axial direction Da (hereinafter simply referred to as ⁇ axial direction Da'') along the central axis AX1 of the nozzle body 10.
  • a large diameter portion 14 having a larger outer diameter than the tip portion is formed at the rear end portion, which is the other end portion in the axial direction Da of the nozzle body 10.
  • a second internal space 140 is formed in this large diameter portion 14 .
  • the first internal space 130 and the second internal space 140 communicate with each other through a communication hole 16 formed along the axial direction Da of the nozzle body 10.
  • a valve body 20 is disposed inside the nozzle body 10 so as to be movable along the axial direction Da.
  • the valve body 20 is formed into a cylindrical shape.
  • the valve body 20 has a rear end portion 21 , a tip portion 23 , and an intermediate portion 22 that is intermediate between the rear end portion 21 and the tip portion 23 .
  • the distal end portion 23 is formed on the distal end side of the valve body 20 in the axial direction Da
  • the rear end portion 21 is formed on the rear end side of the valve body 20 in the axial direction Da.
  • a flange portion 214 is formed closer to the tip end than the rear end side sliding portion 212 in the axial direction Da.
  • the diameter of the flange portion 214 is larger than the diameter of the rear end side sliding portion 212 and the inner diameter of the insertion hole 31 of the movable core 30.
  • the flange portion 214 protrudes radially outward from the outer circumferential surface of the rear end side sliding portion 212. Further, an end surface 214a of the flange portion 214 on the distal end side in the axial direction Da is in contact with an end surface on the rear end side of the movable core 30 in the axial direction Da, which will be described later.
  • the magnetic core 40 is a member that attracts the movable core 30 with magnetic attraction force.
  • the magnetic core 40 is formed into a substantially cylindrical shape with unevenness on its outer peripheral surface.
  • the tip portion of the magnetic core 40 in the axial direction Da is press-fitted inside the large diameter portion 14 of the nozzle body 10, that is, into the second internal space 140.
  • the nozzle body 10 and the magnetic core 40 are joined by welding. Thereby, the gap between the nozzle body 10 and the magnetic core 40 is sealed, and the space inside the nozzle body 10 is sealed.
  • the distal end portion 401 of the magnetic core 40 faces the end surface of the movable core 30 disposed in the second internal space 140 on the rear end side in the axial direction Da.
  • the opposing ends of the movable core 30 in the magnetic core 40 may be coated with hard chrome plating, electroless nickel plating, or the like. Thereby, the durability and reliability of the tip portion 401 of the magnetic core 40 that the movable core 30 collides with can be improved.
  • the coil 50 When the coil 50 is energized by the ECU, magnetic flux flows through the magnetic circuit including the magnetic core 40, movable core 30, nozzle body 10, and housing 70. Then, a magnetic attraction force that attracts the movable core 30 is generated in the magnetic core 40 .
  • the magnetic attraction force of the magnetic core 40 exceeds the biasing force of the first spring 61, that is, the set load, the movable core 30 moves toward the magnetic core 40.
  • the movable core 30 moves until the end surface facing the magnetic core 40, that is, the end surface on the rear end side collides with the end surface on the front end side of the magnetic core 40.
  • the tip portion 23 of the valve body 20 separates from the injection hole forming member 12. Therefore, the flow path leading to the injection hole 18 formed between the valve body 20 and the injection hole forming member 12 is opened, and the injection holes 18 and 19 are in an open state.
  • valve body 20 When the valve body 20 is in the open position (open state), fuel is introduced into the opening 43 of the magnetic core 40 via the filter 90 . The fuel then flows toward the nozzle body 10 through the through hole 42 of the adapter. Further, the fuel passes through the adjustment member 62 and the first spring 61 arranged in the through hole 41 of the magnetic core, and flows through the flow path formed between the valve body 20 and the through hole 41 of the magnetic core 40. The fuel then flows into the second internal space 140 of the nozzle body 10 via the eccentric through hole 32 of the movable core 30.
  • the fuel flowing into the second internal space 140 passes through the gap G10 formed between the valve body 20 and the communication hole 16 of the nozzle body 10, and flows into the first internal space 130 of the nozzle body 10.
  • the fuel then flows through the flow path FC formed between the tip 23 of the valve body 20 and the injection hole forming member 12 and is injected into the combustion chamber via the injection holes 18 and 19.
  • the ECU interrupts the energization of the coil 50
  • the magnetic flux flowing through the magnetic circuit including the magnetic core 40, movable core 30, nozzle body 10, and housing 70 disappears.
  • the magnetic attraction force of the magnetic core 40 that attracts the movable core 30 also disappears. Therefore, the elastic force in the first spring 61 that biases the valve body 20 toward the injection hole forming member 12 of the nozzle body 10 is the same as the elastic force in the second spring 63 that biases the movable core 30 toward the magnetic core 40. Return to an initial state greater than .
  • valve body 20 is urged toward the injection hole forming member 12 of the nozzle body 10 by the first spring 61, and moves toward the tip along the axial direction Da. Furthermore, the movable core 30 that engages with the engaging portion 213 of the valve body 20 moves toward the distal end side along the axial direction Da together with the valve body 20. As a result, the tip 23 of the valve body 20 is pressed against the seat surface 124 of the injection hole forming member 12, which will be described later, and the flow path FC leading to the injection holes 18 and 19 is closed by the valve body 20, resulting in a closed state. . As a result, fuel injection by the fuel injection device 1 is stopped.
  • FIG. 3 is an enlarged cross-sectional view showing the vicinity of the valve member 24 and anchor 30 in the fuel injection device 1. As shown in FIG. Note that FIG. 2 shows a valve closed state. FIG. 3 is an enlarged view showing the valve body 20 of the valve member 24 and the gap forming member 101 in the fuel injection device 1. As shown in FIG.
  • the valve member 24 is composed of the valve body 20, the rod head 102, the third spring 104, and the gap forming member 101.
  • a rod head 102 is formed on the rear end side of the valve body 20.
  • the rod head 102 is formed into a substantially disk shape.
  • the rod head 102 forms a flow path between the rod head 102 and the through hole 41 of the magnetic core 40.
  • a connection recess 127 that is recessed toward the rear end in the axial direction Da is formed at the end of the rod head 102 on the one end side in the axial direction, that is, on the front end side in the axial direction Da.
  • the connection recess 127 fits into the engagement portion 213. Thereby, the rod head 102 is connected to the valve body 20.
  • first spring 61 is in contact with the end surface of the rod head 102 on the rear end side in the axial direction Da.
  • a third spring 104 is in contact with the lower end surface of the rod head 102 on the distal end side in the axial direction Da.
  • the third spring 104 is interposed between the rod head 102 and a gap forming member 101 (described later), and biases the gap forming member 101 toward the movable core 30.
  • the flange portion 214 of the valve body 20 faces the rear end surface 301 of the movable core 30.
  • the valve body 20 is in the closed state, there is a gap G1 between the end surface 214a on the tip side, which is the end surface on the one end side in the axial direction Da of the flange portion 214, and the tip 401 of the magnetic core 40.
  • an end surface 214a on the distal side of the flange portion 214 faces an end surface 214a on the distal side with a gap G2 provided therebetween by a gap forming member 101, which will be described later.
  • the sum of the gap G2 and the gap G1 becomes the gap between the distal end 401 of the magnetic core 40 and the rear end surface 301 of the movable core 30, a so-called magnetic attraction gap.
  • FIG. 3 is an enlarged partial cross-sectional view showing the collar portion 214 and the gap forming member 101. As shown in FIG. 3
  • the gap forming member 101 is formed into a substantially cylindrical shape.
  • the gap forming member 101 has an opposing portion 11 that radially faces the flange portion 214 of the valve body 20, and a small diameter portion 120 that is guided by the rear sliding portion 212 of the valve body.
  • the opposing portion 11 and the small diameter portion 120 are formed on a concentric circle, and the opposing portion 11 is formed closer to the tip side than the small diameter portion 120 in the axial direction Da.
  • the diameter of the opposing portion 11 is larger than the diameter of the small diameter portion 120.
  • a small diameter hole 122 is formed in the small diameter portion 120.
  • the small diameter hole 122 penetrates from the upper end surface, which is the end surface on the rear end side of the gap forming member 101 in the axial direction Da, to the opposing portion 11 .
  • the small diameter hole 122 communicates with the opposing portion 11 .
  • the rear end sliding portion 212 of the valve body 20 is inserted into the small diameter hole 122 .
  • the inner diameter of the small diameter hole 122 is set larger than the diameter of the rear end side sliding portion 212. Therefore, the gap forming member 101 can be displaced relative to the valve body 20.
  • a step surface 13 is formed at a location where the opposing portion 11 and the small diameter portion 120 of the gap forming member 101 connect.
  • the stepped surface 13 projects approximately perpendicularly from the outer circumferential surface of the small diameter portion 120 toward the outside in the radial direction.
  • the tip end side of the third spring 104 in the axial direction Da is in contact with this step surface 13 .
  • the third spring 104 biases the gap forming member 101 toward the movable core 30. Therefore, the lower end surface 121, which is the end surface of the gap forming member 101 on the distal end side in the axial direction Da, comes into contact with the end surface 301 of the movable core 30 on the rear end side.
  • a thick portion 11b and a thin portion 11c are formed on the outer peripheral surface of the facing portion 11.
  • the thick portion 11b is formed on the distal end side of the opposing portion 11 in the axial direction Da. That is, the thick portion 11b is formed closer to the rear end surface 301 of the movable core 30 than the center of the outer peripheral surface of the opposing portion 11.
  • the thick portion 11b protrudes outward in the radial direction from the outer circumferential surface of the opposing portion 11, and has the maximum outer diameter of the opposing portion 11.
  • the thin portion 11c is formed closer to the rear end of the opposing portion 11 in the axial direction Da than the thick portion 11b, that is, closer to the stepped surface 13 and the small diameter portion 120.
  • the thin portion 11c is formed to have a smaller diameter than the thick portion 11b.
  • FIG. 4 is a cross-sectional view showing a state before the pre-stroke amount is adjusted in the fuel injection device 1 of this example.
  • the gap forming member 101 is set between the first jig 501 and the second jig 502 in a state where it is assembled to the valve body 20. Specifically, the flange portion 214 of the valve body 20 is accommodated in the facing portion 11 . Then, the valve body 20 and the gap forming member 101 are arranged above the first jig 501. Further, the second jig 502 is arranged above the first jig 501 so as to sandwich the flange portion 214 of the valve body 20 and the gap forming member 101.
  • the first jig 501 also has an insertion hole 511 through which a portion 211 of the outer circumferential surface of the valve body 20 on the distal side of the flange portion 214 can be inserted.
  • the diameter of the insertion hole 511 is set to be smaller than the outer diameter of the flange portion 214 and larger than the part 211 of the outer peripheral surface of the valve body 20.
  • the first jig 501 has an annular contact surface 512 that comes into contact with the end surface 214a of the collar portion 214 on the distal end side. The contact surface 512 is formed at the opening edge 513 of the insertion hole 511.
  • the second jig 502 is formed with a fitting hole 521 through which the small diameter portion 120 of the gap forming member 101 can be inserted.
  • the diameter of the fitting hole 521 is smaller than the outer peripheral surface of the opposing portion 11 of the gap forming member 101 and larger than the outer peripheral surface of the small diameter portion 120.
  • the second jig 502 has a second pressurizing surface 522 that comes into contact with the stepped surface 13 of the gap forming member 101.
  • the gap forming member 101 is plastically deformed until it contacts the rear end surface 214b of the collar portion 214. As a result, the size of the gap G4 described above becomes zero.
  • the prestroke amount can be precisely adjusted and managed.
  • the opposing portion 11 of the gap forming member 101 expands outward in the radial direction due to the plastic deformation.
  • the center portion of the outer peripheral surface of the opposing portion 11 has the maximum outer diameter. Therefore, the diameter of the opposing portion 11 becomes larger than before the prestroke adjustment.
  • the facing part 11 when the facing part 11 is formed with a uniform thickness, it is necessary to set the shape and dimensions of the facing part 11 in consideration of the expansion toward the outer diameter at zero during pre-stroke adjustment. If an attempt is made to increase the lower end surface 121 of the opposing portion 11, the outermost diameter portion of the opposing portion 11 of the gap forming member 101 after plastic deformation becomes even larger. As a result, not only is it impossible to insert the gap forming member 101 into the through hole 41 of the magnetic core 40, but also it is impossible to maximize the contact area. Furthermore, when the through hole 41 of the magnetic core 40 is enlarged, there is a problem in that the magnetic characteristics of the fuel injection device 1 are affected, and the maximum operating fuel pressure of the fuel injection device 1 is reduced.
  • FIG. 6 is an enlarged sectional view showing the vicinity of a gap forming member in a fuel injection device according to a second embodiment.
  • the second thick portion 11e is formed closer to the stepped surface 13 than the thin portion 11c, that is, on the upstream side of the opposing portion 11B. Therefore, in the opposing portion 11B according to the second embodiment, thick portions 11b and 11e are formed at both ends of the thin portion 11c in the axial direction, respectively.
  • a fuel injection device having such a gap forming member 101B can also provide the same effects as the fuel injection device 1 according to the first embodiment described above.
  • 1...Fuel injection device 10...Nozzle body, 11, 11B...opposing part, 11a...inner peripheral surface, 11b...thick wall part, 11c...thin wall part, 11d...step, 11e...second thick wall part, 11f...inner diameter , 11g...inner diameter, 13...stepped surface, 20...valve body, 21...rear end, 22...middle part, 23...tip, 24...valve member, 30...movable core, 31...insertion hole, 32...eccentric penetration Hole, 40... Magnetic core, 41... Through hole, 42... Through hole, 43... Opening, 50... Coil, 51... Coil bobbin, 62... Adjustment member, 70... Housing, 71... Through hole, 80... Connection part, 81 ...

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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)

Abstract

Ce dispositif d'injection de carburant comprend : un noyau magnétique ; un noyau mobile attiré par le noyau magnétique ; un corps de soupape qui comporte une bride sur le côté amont du noyau mobile ; et un élément de formation d'espace qui forme un espace axial entre la bride et le noyau mobile dans un état fermé de soupape. L'élément de formation d'espace possède une partie opposée en regard de la bride dans une direction radiale. Une partie épaisse et une partie mince présentant un diamètre externe inférieur au diamètre externe de la partie épaisse sont formées dans la surface circonférentielle externe de la partie opposée. La partie épaisse est formée dans la partie opposée sur le côté de surface d'extrémité qui vient en butée contre le noyau mobile.
PCT/JP2022/023898 2022-06-15 2022-06-15 Dispositif d'injection de carburant Ceased WO2023242980A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/023898 WO2023242980A1 (fr) 2022-06-15 2022-06-15 Dispositif d'injection de carburant

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/023898 WO2023242980A1 (fr) 2022-06-15 2022-06-15 Dispositif d'injection de carburant

Publications (1)

Publication Number Publication Date
WO2023242980A1 true WO2023242980A1 (fr) 2023-12-21

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Family Applications (1)

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PCT/JP2022/023898 Ceased WO2023242980A1 (fr) 2022-06-15 2022-06-15 Dispositif d'injection de carburant

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WO (1) WO2023242980A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008075478A (ja) * 2006-09-19 2008-04-03 Keihin Corp 電磁式燃料噴射弁及びその製造方法
JP2012237267A (ja) * 2011-05-13 2012-12-06 Hitachi Automotive Systems Ltd 燃料噴射弁のストローク調整方法及び燃料噴射弁
WO2021255986A1 (fr) * 2020-06-18 2021-12-23 日立Astemo株式会社 Procédé de réglage de pré-course pour soupape d'injection de combustible

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008075478A (ja) * 2006-09-19 2008-04-03 Keihin Corp 電磁式燃料噴射弁及びその製造方法
JP2012237267A (ja) * 2011-05-13 2012-12-06 Hitachi Automotive Systems Ltd 燃料噴射弁のストローク調整方法及び燃料噴射弁
WO2021255986A1 (fr) * 2020-06-18 2021-12-23 日立Astemo株式会社 Procédé de réglage de pré-course pour soupape d'injection de combustible

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