WO2019092875A1 - Fuel injection valve - Google Patents

Fuel injection valve Download PDF

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Publication number
WO2019092875A1
WO2019092875A1 PCT/JP2017/040688 JP2017040688W WO2019092875A1 WO 2019092875 A1 WO2019092875 A1 WO 2019092875A1 JP 2017040688 W JP2017040688 W JP 2017040688W WO 2019092875 A1 WO2019092875 A1 WO 2019092875A1
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WO
WIPO (PCT)
Prior art keywords
valve
yoke
outer diameter
axial direction
peripheral surface
Prior art date
Application number
PCT/JP2017/040688
Other languages
French (fr)
Japanese (ja)
Inventor
範久 福冨
恭輔 渡邉
章男 新宮
宗実　毅
学 平井
Original Assignee
三菱電機株式会社
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 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2019551854A priority Critical patent/JP6721268B2/en
Priority to PCT/JP2017/040688 priority patent/WO2019092875A1/en
Priority to CN201780096433.3A priority patent/CN111295507B/en
Publication of WO2019092875A1 publication Critical patent/WO2019092875A1/en

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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
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for

Definitions

  • the present invention relates to an electromagnetic fuel injection valve mounted on an engine.
  • the conventional fuel injection valve has a magnetic throttling portion 13 on the outer diameter side of an air gap 58 between the armature 17 and the core 2 as shown in FIGS. Both axial ends of the yoke 45 disposed outside are welded to the core 2 and the valve holder 10.
  • This type of fuel injection valve has a structure in which the valve seat 18 is displaced by the deformation of the orifice plate 22 as shown in the drawing of Patent Document 2 to adjust the lift amount of the valve body.
  • the engine is required to perform highly accurate air-fuel ratio control, and a fuel injection valve capable of injecting a minute amount with high accuracy is required. If the spring load of the fuel injection valve is increased and the valve closing time is advanced, the amount of fuel injection injected at the time of valve closing is reduced, and accurate injection can be performed to a minute injection amount. On the other hand, when the spring load is increased, the electromagnetic force at the time of valve opening is insufficient, and there is a problem that the valve can not be opened due to the insufficient electromagnetic force under the condition that the driving voltage at engine start is low. In order to increase the electromagnetic force, it is conceivable to increase the size of the amateur, but due to the increase in mass of the amateur, the valve closing time can not be delayed to reduce the fuel injection amount.
  • the inner peripheral surface of the magnetic throttle portion 13 is a sliding surface with the armature sliding portion 36, and when the magnetic throttle portion 13 is buckled, the armature sliding portion The clearance between the magnetic diaphragm 36 and the inner circumferential surface of the magnetic throttling portion 13 is lost, and the sliding failure of the armature 17 occurs.
  • the fuel injection valve comprises a valve seat in which a fuel passage is formed; A valve element which moves to the valve opening side in the axial direction and separates from the valve seat to open the fuel passage, or moves to the valve closing side in the axial direction, and abuts on the valve seat to close the fuel passage;
  • a cylindrical coil A cylindrical core disposed on the inner diameter side of the coil; The core is disposed on the valve closing side in the axial direction with a gap from the core, and is attracted to the valve opening side in the axial direction by magnetic flux generated by energization of the coil, and the valve body is opened on the axial direction
  • a cylindrical valve holder containing the valve seat, the valve body, and the armature on the inner diameter side
  • a cylindrical yoke covering the outside of the coil The yoke includes a cylindrical yoke outer diameter portion covering the outer diameter side of the coil, a cylindrical yoke closed valve side portion extending from the yoke outer diameter
  • the gap outer diameter portion is formed to be thinner than the core connection portion, the armature sliding portion, and the holder press-fit portion.
  • the axial friction force generated between the inner peripheral surface of the yoke closed side and the outer peripheral surface of the holder press-fit portion is smaller than the axial deformation load at which the gap outer diameter portion starts plastic deformation. is there.
  • the gap outer diameter portion of the valve holder disposed on the outer diameter side of the gap between the core and the armature is thinned, the magnetic flux passing through the gap outer diameter portion It is possible to reduce, to increase the magnetic flux through the gap and to increase the attraction of the amateur.
  • the core and the yoke opening side of the yoke are welded, but the holder press-in portion of the valve holder and the yoke closing side of the yoke are connected by pressure insertion.
  • the load in the axial direction It is configured to be able to escape.
  • the frictional force in the axial direction of the press-fit portion is smaller than the deformation load in the axial direction of the gap outer diameter portion, the axial load applied to the gap outer diameter portion is due to contraction of the yoke after welding.
  • the inner peripheral surface of the yoke valve-closing side and the outer peripheral surface of the holder press-fit portion of the valve holder mutually slide, and the load in the axial direction can be reduced. The deformation of the thinned outer diameter portion can be suppressed.
  • the gap outer diameter portion is thinned and the armature sliding portion is not thinned, it is possible to suppress deformation of the armature sliding portion even if the gap outer diameter portion is deformed by manufacturing variation. Therefore, it is possible to suppress the occurrence of the sliding failure between the armature sliding portion and the armature, and it is possible to reduce the risk of the malfunction of the fuel injection valve.
  • the armature sliding portion is disposed closer to the valve opening side in the axial direction than the holder press-in portion, and is not press-fitted to the yoke closed side. Therefore, the armature sliding portion is unlikely to be deformed by press-fitting, and it is possible to make it difficult to cause a sliding failure due to the deformation of the inner circumferential surface of the armature sliding portion.
  • FIG. 1 is a cross-sectional view of the fuel injection valve 1 according to the present embodiment, taken along a plane passing through the axis Y.
  • FIG. 2 is a cross-sectional view of an essential part of the fuel injection valve 1.
  • 1 and 2 are views of the fuel injection valve 1 in the closed state.
  • the front end of the fuel injection valve 1 is attached so as to be exposed to an intake passage (not shown) of the engine, and fuel is supplied to the rear end of the fuel injection valve 1.
  • the fuel injection valve 1 is opened by an electric signal from the control device to inject fuel into the intake passage.
  • the fuel injection valve 1 includes a valve seat 3 in which a fuel passage 3a is formed, and a valve body 2 for opening and closing the fuel passage 3a.
  • a valve seat 3 in which a fuel passage 3a is formed
  • a valve body 2 for opening and closing the fuel passage 3a.
  • the valve body 2 is a needle having a spherical tip 2a for closing the fuel passage 3a and a cylindrical (cylindrical in this example) pipe 2b extending from the tip 2a to the valve opening side X1 in the axial direction. It is considered to be a valve.
  • the pipe 2b is provided with a plurality of holes on its side surface, and is fixed to the tip 2a by welding.
  • the fuel injection valve 1 is provided on the valve closing side X2 in the axial direction of the valve seat 3, and includes an orifice plate 4 in which injection holes 4a are formed.
  • the direction in which the valve body 2 moves is defined as the axial direction X.
  • the axial direction X is parallel to the axial center Y of each cylindrical member.
  • the valve closing side X2 in the axial direction is the tip end side of the fuel injection valve 1, and the valve opening side X1 in the axial direction is the rear end side of the fuel injection valve 1.
  • Each cylindrical member is disposed around the axis Y.
  • the valve seat 3 and the orifice plate 4 are disposed at the end (tip) of the valve closing side X2 in the axial direction of the fuel injection valve 1, and fuel is injected.
  • the end (rear end) of the valve opening side X1 in the axial direction of the fuel injection valve 1 opens in the valve opening side X1 in the axial direction, and fuel of about 300 kPa is received from the fuel pipe (not shown) in the opening. Supplied.
  • An O-ring 13 is fitted on the outer peripheral surface of the rear end portion of the fuel injection valve 1, and the connection with the fuel pipe is sealed.
  • the fuel injection valve 1 is disposed with a gap 6 at the valve closing side X2 in the axial direction of the core 7 and the cylindrical core 7 disposed on the inner diameter side of the coil 5 and the core 5.
  • a tubular armature 8 attracted to the valve opening side X1 in the axial direction by magnetic flux generated by energization of the coil 5 and a tubular yoke 11 covering the outside of the coil 5 are provided.
  • the core 7, the yoke 11, and the armature 8 are made of a magnetic material such as iron.
  • the coil 5 has a bobbin 5a on which a copper wire is wound.
  • the bobbin 5a is integrally formed with a support member of the terminal 12 described later.
  • the core 7 extends to the end (rear end) of the valve opening side X1 of the fuel injection valve 1 in the axial direction.
  • the armature 8 is a cylindrical main body portion 8a and a portion extending from the main body portion 8a to the valve closing side X2 in the axial direction, and has the same inner diameter as the main body portion 8a and an outer diameter smaller than the main body portion 8a And a cylindrical boss 8b.
  • the end face on the valve closing side X2 of the core 7 (core small diameter portion 7a described later) in the axial direction and the end face of the valve opening side X1 on the axial direction of the armature 8 (body portion 8a) are opposed in the axial direction X .
  • the gap 6 in the axial direction X between the core 7 and the armature 8 occurs in the closed state, and disappears in the open state.
  • the portion on the valve closing side X2 in the axial direction of the main body portion 8a has an outer diameter larger than the portion on the valve opening side X1 in the axial direction, and slides with the inner circumferential surface of the armature sliding portion 9c of the valve holder 9 Is a sliding surface.
  • the inner peripheral surface of the armature 8 is press-fitted and fixed to the outer peripheral surface of the end of the valve opening side X1 in the axial direction of the pipe 2b.
  • the fuel injection valve 1 includes a spring 15 disposed on the inner diameter side of the core 7 and pressing the armature 8 against the valve closing side X2 in the axial direction.
  • the end of the axial valve-opening side X1 of the spring 15 is supported by a cylindrical (in this example, cylindrical) rod 16 and the end of the axial valve-closing side X2 of the spring 15 is connected to the armature 8
  • the fixed pipe 2b is pressed on the valve closing side X2 in the axial direction.
  • the outer peripheral surface of the rod 16 is press-fitted and fixed to the inner peripheral surface of the core 7.
  • the fuel injection valve 1 comprises a terminal 12 for connecting the coil 5 to an external control device.
  • the terminal 12 is disposed at a side portion of the fuel injection valve 1.
  • the coil 5 When power is supplied from the control device to the terminal 12, the coil 5 generates a magnetic flux, and the magnetic flux of the coil 5 generates a suction force for attracting the armature 8 to the valve opening side X1 in the axial direction.
  • the attraction force of the magnetic flux to the valve opening side X1 in the axial direction exceeds the pressing force of the spring 15 to the valve closing side X2 in the axial direction, and the armature 8 and the valve body 2 move to the valve opening side X1 in the axial direction.
  • the valve body 2 is separated from the valve seat 3 and is in an open state.
  • the fuel injection valve 1 includes a valve seat 3, a valve body 2, and a cylindrical valve holder 9 accommodating an armature 8 on the inner diameter side.
  • the valve holder 9 also accommodates the orifice plate 4 on the inner diameter side.
  • the orifice plate 4 includes a welded portion 4 c welded to a portion on the valve closing side X 2 in the axial direction of the valve seat 3 and a welded portion 4 b welded to the valve holder 9. That is, the valve seat 3 is fixed to the valve holder 9 via the orifice plate 4.
  • the yoke 11 extends from the yoke outer diameter portion 11 a to the valve closing side X 2 in the axial direction, and supports the valve holder 9, and the cylindrical yoke closed to support the valve holder 9.
  • a valve side portion 11b and a yoke open side portion 11c extending from the yoke outer diameter portion 11a to the valve opening side X1 in the axial direction and welded to the outer peripheral surface of the core 7 are provided.
  • the yoke outer diameter portion 11a and the yoke valve closing side portion 11b are integrally formed members, and the diameter of the yoke valve closing side portion 11b is smaller in two stages than the diameter of the yoke outer diameter portion 11a. It is formed in a two-step cylindrical shape.
  • the yoke valve-opening side portion 11c is a plate-like member, and has a welded portion 11d welded to the outer peripheral surface of the core 7 and a welded portion 11e welded to the yoke outer diameter portion 11a.
  • the yoke opening side portion 11c is a ring plate-like member in which a circumferential portion in which the terminal 12 is disposed is cut away, and the outer peripheral surface of the core 7 and the inner peripheral surface of the yoke outer diameter portion 11a Block the opening on the valve opening side X1 in the axial direction of the cylindrical space between them.
  • the valve holder 9 has a core connecting portion 9a whose inner peripheral surface is fitted to the outer peripheral surface of the core 7 and a portion on the valve closing side X2 in the axial direction of the core connecting portion 9a.
  • the inner circumferential surface of the gap outer diameter portion 9b disposed on the outer diameter side of the gap 6 between the armature 8 and the valve closing side X2 in the axial direction with respect to the gap outer diameter portion 9b
  • the armature sliding portion 9c sliding on the outer peripheral surface of the axial closing side X2 of the main body portion 8a and the valve closing side X2 in the axial direction with respect to the armature sliding portion 9c
  • the holder press-fit portion 9d press-fit into the inner peripheral surface of the yoke valve-closing side portion 11b.
  • valve holder 9 is a portion on the valve closing side X2 in the axial direction with respect to the holder press-fit portion 9d, and is a holder tip portion 9e accommodating the valve seat 3, the valve body 2 and the orifice plate 4 on the inner diameter side. have.
  • the outer diameter of the armature sliding portion 9c is smaller than the outer diameter of the holder press-in portion 9d, and the outer peripheral surface of the armature sliding portion 9c is not press-contacted with the inner peripheral surface of the yoke valve closing side 11b. It is configured not to be.
  • the end of the axial valve closing side X2 of the core 7 is a cylindrical core small diameter portion 7a whose outer diameter is smaller than that of the valve opening side X1, and the inner periphery of the coil 5 (bobbin 5a) Between the surface and the outer peripheral surface of the core small diameter portion 7a, a cylindrical gap 7b (hereinafter referred to as the core small diameter portion clearance 7b) which is opened on the valve closing side X2 in the axial direction is generated.
  • the core connecting portion 9a of the valve holder 9 is disposed in the core small diameter portion gap 7b.
  • the core connection portion 9a of the valve holder 9 is formed in a cylindrical shape, and the core connection is performed by the weld portion 9f in a state where the inner peripheral surface of the core connection portion 9a is fitted to the outer peripheral surface of the core small diameter portion 7a by press fitting.
  • the portion 9a is welded to the core small diameter portion 7a.
  • the gap outer diameter portion 9b is thinner than the core connection portion 9a, the armature sliding portion 9c, and the holder press-fit portion 9d. That is, the radial thickness of the gap outer diameter portion 9b is smaller than the radial thickness of the core connection portion 9a, the armature sliding portion 9c, and the holder press-fit portion 9d.
  • the magnetic flux passing through the gap outer diameter portion 9b can be reduced, the magnetic flux passing through the gap 6 between the core 7 and the armature 8 can be increased, and the attraction of the armature 8 can be increased.
  • the gap outer diameter portion 9 b is thinned, the gap outer diameter portion 9 b is easily deformed.
  • the portion on the valve opening side X1 in the axial direction than the gap outer diameter portion 9b and the portion on the valve closing side X2 in the axial direction are connected via the yoke 11, and when the yoke 11 contracts due to cooling after welding, A load in the axial direction X is applied to the gap outer diameter portion 9 b.
  • the load in the axial direction X exceeds the deformation load B in the axial direction in which the gap outer diameter portion 9b starts plastic deformation, the gap outer diameter portion 9b is deformed, the gap 6 becomes narrow, and the armature 8 is opened.
  • the amount of movement to the valve opening side X1 in the axial direction decreases, and a valve opening failure occurs. Therefore, it is desirable to provide a fuel injection valve 1 that can suppress deformation of the gap outer diameter portion 9b even if a load in the axial direction X is applied to the gap outer diameter portion 9b due to shrinkage of the yoke 11 due to cooling after welding.
  • the holder press-fit portion 9d of the valve holder 9 and the yoke 11 are connected by press fitting. Therefore, the portion on the valve closing side X2 in the axial direction with respect to the gap outer diameter portion 9b is connected to the yoke 11 by the frictional force A generated by the surface pressure of the press-fit portion. The load in the axial direction X can be released.
  • the frictional force A in the axial direction X generated between the inner peripheral surface of the yoke valve-closing side 11b of the yoke 11 and the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 is the clearance outer diameter portion 9b of the valve holder 9. Is smaller than the axial deformation load B at which the plastic deformation starts (A ⁇ B).
  • the yoke valve closing side portion Before the load in the axial direction X applied to the gap outer diameter portion 9b reaches the deformation load B of the gap outer diameter portion 9b due to contraction or the like of the yoke 11 after welding, the yoke valve closing side portion The inner peripheral surface 11b and the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 mutually slide to reduce the load in the axial direction X, and the deformation of the gap outer diameter portion 9b can be suppressed.
  • the armature sliding portion 9c is formed even if the gap outer diameter portion 9b is deformed due to manufacturing variations. Can be suppressed from being deformed. Therefore, it is possible to suppress the occurrence of a sliding failure between the armature sliding portion 9c and the armature 8 (portion on the valve closing side X2 in the axial direction of the main body portion 8a), and to reduce the risk of operation failure of the fuel injection valve 1. Can.
  • the armature sliding portion 9c is disposed closer to the valve opening side X1 in the axial direction than the holder press-fit portion 9d, and is not press-fitted to the yoke closed side 11b. Therefore, the armature sliding portion 9c is difficult to be deformed by press-fitting, and the sliding failure due to the deformation of the inner peripheral surface of the armature sliding portion 9c is unlikely to occur.
  • the inner peripheral surface of the valve holder 9 from the gap outer diameter portion 9b to the armature sliding portion 9c is a cylindrical surface having the same diameter. According to this configuration, since the inner diameters of the gap outer diameter portion 9b and the armature sliding portion 9c are simultaneously managed, the inner diameter of the gap outer diameter portion 9b is managed with high accuracy, similarly to the armature sliding portion 9c, It is possible to suppress the variation in the deformation load B of the gap outer diameter portion 9b.
  • the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 integrated with the core 7 is press-fit into the inner peripheral surface of the yoke valve closing side 11b integrally formed with the yoke outer diameter portion 11a.
  • the coil 5 integrally formed with the terminal 12 is inserted into a cylindrical space between the outer peripheral surface of the core 7 and the inner peripheral surface of the yoke outer diameter portion 11a.
  • annular plate-like yoke valve-opened side portion 11c in which the terminal 12 portion is cut out is disposed at the opening of the valve-opening side X1 in the axial direction of the cylindrical space, and the yoke outer diameter portion 11a and the yoke valve-opened side
  • the boundary with the portion 11c is welded to form a welded portion 11e
  • the boundary between the core 7 and the yoke opening side 11c is welded to form a welded portion 11d.
  • the inner peripheral surface of the yoke closed valve side portion 11b of the yoke 11 and the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 mutually slide, and the gap outer diameter of the thinned valve holder 9
  • the load in the axial direction X applied to the portion 9 b can be prevented from reaching the deformation load B, and the deformation of the gap outer diameter portion 9 b can be suppressed.
  • the resin 18 is molded on the assembled parts. Then, the outer peripheral surface of the rod 16 is pressed into the inner peripheral surface of the core 7. Then, the spring 15, the armature 8 pressed into the pipe 2 b, and the valve body 2 are inserted into the core 7 and the valve holder 9. After the orifice plate 4 and the valve seat 3 welded to each other by the welding portion 4 c are inserted into the inside of the valve holder 9 and positioned relative to the valve holder 9, the outer peripheral portion of the orifice plate 4 and the inner peripheral surface of the valve holder 9 Are welded all around to form a welded portion 4b.
  • the orifice plate 4 is axially moved by the cylindrical jig 19. Is pressed on the valve open side X1.
  • the tip of the jig 19 has a cylindrical protrusion 19 a that protrudes on the valve opening side X1 in the axial direction.
  • the protrusion 19a presses the vicinity of the weld 4c and plastically deforms the portion of the orifice plate 4 between the weld 4c and the weld 4b to open the valve seat 3 in the axial direction with respect to the valve holder 9.
  • the valve lift amount is adjusted by adjusting the distance in the axial direction X of the gap 6 between the core 7 and the armature 8 by displacing the valve side X1.
  • the gap outer diameter portion 9 b (the thickness in the radial direction) of the valve holder 9 is thinner than the orifice plate 4 (the thickness of the plate) in order to increase the suction force of the armature 8.
  • the axial deformation load B at which the gap outer diameter portion 9b of the holder 9 starts plastic deformation is smaller than the axial deformation load C at which the orifice plate 4 starts plastic deformation.
  • the gap outer diameter portion 9b may be deformed.
  • the deformation load C in the axial direction X at which the orifice plate 4 starts plastic deformation is between the inner peripheral surface of the yoke closed valve side portion 11b and the outer peripheral surface of the holder press-fit portion 9d. It is smaller than the sum of the frictional force A in the axial direction X and the deformation load B in the axial direction X at which the thinned outer diameter portion 9 b starts plastic deformation (C ⁇ A + B).
  • the pressing force is a frictional force A between the yoke closing side 11b and the holder press-fit portion 9d.
  • the deformation load B of the gap outer diameter portion 9b can be received to suppress deformation of the gap outer diameter portion 9b. Therefore, the valve lift can be adjusted by deforming the orifice plate 4 without deforming the thinned outer diameter portion 9b.
  • the yoke outer diameter portion 11a and the yoke closed valve side portion 11b which are two-step cylindrically formed integral members are formed by drawing processing and shaving processing. Specifically, as shown in FIG. 4, the plate material is pressed and drawn by a punch (not shown) whose end is formed in a cylindrical shape with two steps. Thereafter, unnecessary portions are cut by cutting, and the state shown in FIG. 5 is obtained. At this time, as shown in FIG. 4, in order to open the lower end, the central portion is punched out by the punching tool 20. At this time, as shown in FIG. An enlarged inner diameter portion 11 f is generated. Therefore, as shown in FIG.
  • the shaving process is performed to remove the inner peripheral surface of the yoke closed side portion 11b with a cutting tool 21 to make it a straight cylindrical surface.
  • the yoke closed valve side portion 11b is a drawn portion formed by drawing, and becomes a shaving portion having an inner peripheral surface formed in a cylindrical shape by shaving.
  • the yoke closed side portion 11b to be the press-fit portion can be manufactured at low cost by the drawing process and the shaving process.
  • the inner peripheral surface of the yoke closed side 11b can be made a straight cylindrical surface suitable for press-fitting, and the inner diameter can be adjusted with high accuracy. Therefore, the surface pressure of the press-fit portion and the frictional force A can be accurately adjusted, and the deformation of the gap outer diameter portion 9b can be suppressed.
  • the embodiment can be appropriately modified or omitted within the scope of the invention.

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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

Provided is a fuel injection valve in which deformation of a thinned valve holder portion due to shrinkage or the like of a yoke after welding can be suppressed. In the fuel injection valve (1), a gap outer diameter part (9b) of a valve holder (9) is arranged on an outer diameter side of a gap (6) between a core (7) and an armature (8), and is thinned. An axial frictional force generated between an inner peripheral surface of a yoke valve closing-side part (11b) and an outer peripheral surface of a holder press-fitting part (9d) is smaller than an axial (X) deformation load at which the gap outer diameter part (9b) starts to deform plastically.

Description

燃料噴射弁Fuel injection valve
　本発明は、エンジンに搭載される電磁式の燃料噴射弁に関するものである。 The present invention relates to an electromagnetic fuel injection valve mounted on an engine.
　従来の燃料噴射弁は、特許文献１の図１、２に示されているようにアマチュア１７とコア２との間のエアギャップ５８の外径側に磁気的な絞り部１３を有し、コイル外側に配置されたヨーク４５の軸方向の両端がコア２及び弁ホルダ１０と溶接されている。 The conventional fuel injection valve has a magnetic throttling portion 13 on the outer diameter side of an air gap 58 between the armature 17 and the core 2 as shown in FIGS. Both axial ends of the yoke 45 disposed outside are welded to the core 2 and the valve holder 10.
　このタイプの燃料噴射弁は、特許文献２の図で示されるようなオリフィスプレート２２の変形により弁座１８を変位させて弁体のリフト量を調節する構造となっている。 This type of fuel injection valve has a structure in which the valve seat 18 is displaced by the deformation of the orifice plate 22 as shown in the drawing of Patent Document 2 to adjust the lift amount of the valve body.
国際公開第９６／２４７６３号WO 96/24763 国際公開第９２／０３６５３号WO 92/03653
　車両の排ガス規制の強化に伴いエンジンには高精度な空燃比制御が必要とされており、微小な量まで高精度に噴射可能な燃料噴射弁が求められている。燃料噴射弁のバネ荷重を高めて閉弁時間を早めれば閉弁時に噴射される燃料噴射量が減少して微小な噴射量まで精度よく噴射できるようになる。一方、バネ荷重を高めると開弁時の電磁力が不足して、エンジン始動時の駆動電圧が低い条件では、電磁力不足により開弁できなくなるという問題がある。電磁力を増加させるために、アマチュアを大型化することが考えられるが、アマチュアの質量増加により閉弁時間が遅れて燃料噴射量を減少させることができない。 With the tightening of exhaust gas regulations of vehicles, the engine is required to perform highly accurate air-fuel ratio control, and a fuel injection valve capable of injecting a minute amount with high accuracy is required. If the spring load of the fuel injection valve is increased and the valve closing time is advanced, the amount of fuel injection injected at the time of valve closing is reduced, and accurate injection can be performed to a minute injection amount. On the other hand, when the spring load is increased, the electromagnetic force at the time of valve opening is insufficient, and there is a problem that the valve can not be opened due to the insufficient electromagnetic force under the condition that the driving voltage at engine start is low. In order to increase the electromagnetic force, it is conceivable to increase the size of the amateur, but due to the increase in mass of the amateur, the valve closing time can not be delayed to reduce the fuel injection amount.
　ところで、特許文献１の燃料噴射弁において、磁気絞り部１３を薄くすると、この部分の通過磁束が減少し、エアギャップ５８を通る磁束が増加するので、アマチュア１７を大型化しないでも電磁力を増加させることができる。しかし、ヨーク４５の軸方向の両端を溶接した後の冷却によるヨーク４５の収縮により、溶接間の構造中で最も薄い磁気絞り部１３に集中的にストレスがかかり、変形が生じる可能性がある。磁気絞り部１３を含む弁ホルダ１０は、コア２及びアマチュア１７を収容しており、磁気絞り部１３の変形によりコア２とアマチュア１７との相対位置が変化し、弁リフト量が変化する。特許文献１の燃料噴射弁では、磁気絞り部１３の内周面が、アマチュア摺動部３６との摺動面となっており、磁気絞り部１３が座屈した場合には、アマチュア摺動部３６と磁気絞り部１３の内周面とのクリアランスがなくなりアマチュア１７の摺動不良が発生する。 By the way, in the fuel injection valve of Patent Document 1, when the magnetic throttle portion 13 is thinned, the passing magnetic flux in this portion is decreased and the magnetic flux passing through the air gap 58 is increased. Therefore, the electromagnetic force is increased even if the armature 17 is not enlarged. It can be done. However, due to the contraction of the yoke 45 due to cooling after welding the axial both ends of the yoke 45, stress may be intensively applied to the thinnest magnetic narrowed portion 13 in the structure between welding, and deformation may occur. The valve holder 10 including the magnetic throttling portion 13 accommodates the core 2 and the armature 17. Due to the deformation of the magnetic throttling portion 13, the relative position between the core 2 and the armature 17 changes, and the valve lift amount changes. In the fuel injection valve of Patent Document 1, the inner peripheral surface of the magnetic throttle portion 13 is a sliding surface with the armature sliding portion 36, and when the magnetic throttle portion 13 is buckled, the armature sliding portion The clearance between the magnetic diaphragm 36 and the inner circumferential surface of the magnetic throttling portion 13 is lost, and the sliding failure of the armature 17 occurs.
　そこで、コアとアマチュアとの間の隙間を流れる磁束を増加させるために弁ホルダを薄肉化する場合であっても、溶接後のヨークの収縮等により、薄肉化された弁ホルダの部分が、変形することを抑制できる燃料噴射弁が求められる。 Therefore, even in the case where the valve holder is thinned in order to increase the magnetic flux flowing through the gap between the core and the armature, the portion of the valve holder thinned due to contraction of the yoke after welding is deformed. There is a need for a fuel injection valve that can reduce
　本発明に係る燃料噴射弁は、燃料通路が形成された弁座と、
　軸方向の開弁側に移動し、前記弁座と離間して前記燃料通路を開く、又は軸方向の閉弁側に移動し、前記弁座に当接して前記燃料通路を閉じる弁体と、
　筒状のコイルと、
　前記コイルの内径側に配置された筒状のコアと、
　前記コアの軸方向の閉弁側に前記コアと隙間を空けて配置され、前記コイルの通電により生じた磁束により軸方向の開弁側に吸引され、前記弁体を軸方向の開弁側に移動させる筒状のアマチュアと、
　前記弁座、前記弁体、及び前記アマチュアを内径側に収容した筒状の弁ホルダと、
　前記コイルの外側を覆う筒状のヨークと、を備え、
　前記ヨークは、前記コイルの外径側を覆う筒状のヨーク外径部と、前記ヨーク外径部から軸方向の閉弁側に延出した筒状のヨーク閉弁側部と、前記ヨーク外径部から軸方向の開弁側に延出し、前記コアの外周面に溶接されたヨーク開弁側部と、を有し、
　前記弁ホルダは、内周面が前記コアの外周面に嵌合され、溶接されたコア接続部と、前記コア接続部よりも軸方向の閉弁側の部分であって、前記コアと前記アマチュアとの間の前記隙間の外径側に配置された隙間外径部と、前記隙間外径部よりも軸方向の閉弁側の部分であって、内周面が前記アマチュアの外周面と摺動するアマチュア摺動部と、前記アマチュア摺動部よりも軸方向の閉弁側の部分であって、外周面が前記ヨーク閉弁側部の内周面に圧入されたホルダ圧入部と、を有し、
　前記隙間外径部は、前記コア接続部、前記アマチュア摺動部、及び前記ホルダ圧入部よりも薄肉に形成され、
　前記ヨーク閉弁側部の内周面と前記ホルダ圧入部の外周面との間に生じる軸方向の摩擦力は、前記隙間外径部が塑性変形し始める軸方向の変形荷重よりも小さいものである。 The fuel injection valve according to the present invention comprises a valve seat in which a fuel passage is formed;
A valve element which moves to the valve opening side in the axial direction and separates from the valve seat to open the fuel passage, or moves to the valve closing side in the axial direction, and abuts on the valve seat to close the fuel passage;
With a cylindrical coil,
A cylindrical core disposed on the inner diameter side of the coil;
The core is disposed on the valve closing side in the axial direction with a gap from the core, and is attracted to the valve opening side in the axial direction by magnetic flux generated by energization of the coil, and the valve body is opened on the axial direction With tubular amateur to move,
A cylindrical valve holder containing the valve seat, the valve body, and the armature on the inner diameter side;
And a cylindrical yoke covering the outside of the coil,
The yoke includes a cylindrical yoke outer diameter portion covering the outer diameter side of the coil, a cylindrical yoke closed valve side portion extending from the yoke outer diameter portion to the valve closing side in the axial direction, and the yoke outer side A yoke opening side extending from the radial portion to the valve opening side in the axial direction and welded to the outer peripheral surface of the core;
The valve holder has a core connection portion having an inner peripheral surface fitted to the outer peripheral surface of the core and welded, and a portion on the valve closing side in the axial direction with respect to the core connection portion, the core and the armature A gap outer diameter portion disposed on the outer diameter side of the gap and a portion on the valve closing side in the axial direction with respect to the gap outer diameter portion, the inner circumferential surface being in sliding contact with the outer circumferential surface of the armature A moving armature sliding portion; and a holder press-in portion which is a portion on the valve closing side in the axial direction with respect to the armature sliding portion and whose outer peripheral surface is press-fit into the inner peripheral surface of the yoke valve closing side. Have
The gap outer diameter portion is formed to be thinner than the core connection portion, the armature sliding portion, and the holder press-fit portion.
The axial friction force generated between the inner peripheral surface of the yoke closed side and the outer peripheral surface of the holder press-fit portion is smaller than the axial deformation load at which the gap outer diameter portion starts plastic deformation. is there.
　本発明に係る燃料噴射弁によれば、コアとアマチュアとの間の隙間の外径側に配置された弁ホルダの隙間外径部が薄肉化されているので、隙間外径部を通る磁束を減少させ、隙間を通る磁束を増加させ、アマチュアの吸引力を増加させることができる。コアとヨークのヨーク開弁側部とは溶接されているが、弁ホルダのホルダ圧入部とヨークのヨーク閉弁側部とは圧入により連結されている。よって、隙間外径部よりも軸方向の閉弁側の部分は、圧入部の面圧により生じた摩擦力によりヨークに連結されているため、圧入部が相互に滑ることにより、軸方向の荷重を逃がすことができるように構成されている。そして、圧入部の軸方向の摩擦力は、隙間外径部の軸方向の変形荷重よりも小さくされているので、溶接後のヨークの収縮等により、隙間外径部にかかる軸方向の荷重が、隙間外径部の変形荷重に到達する前に、ヨーク閉弁側部の内周面と弁ホルダのホルダ圧入部の外周面とが相互に滑り、軸方向の荷重を減少させることができ、薄肉化された隙間外径部の変形を抑制できる。 According to the fuel injection valve of the present invention, since the gap outer diameter portion of the valve holder disposed on the outer diameter side of the gap between the core and the armature is thinned, the magnetic flux passing through the gap outer diameter portion It is possible to reduce, to increase the magnetic flux through the gap and to increase the attraction of the amateur. The core and the yoke opening side of the yoke are welded, but the holder press-in portion of the valve holder and the yoke closing side of the yoke are connected by pressure insertion. Therefore, since the portion on the valve closing side in the axial direction rather than the gap outer diameter portion is connected to the yoke by the frictional force generated by the surface pressure of the press-fit portion, the load in the axial direction It is configured to be able to escape. And since the frictional force in the axial direction of the press-fit portion is smaller than the deformation load in the axial direction of the gap outer diameter portion, the axial load applied to the gap outer diameter portion is due to contraction of the yoke after welding. Before the deformation load of the gap outer diameter portion is reached, the inner peripheral surface of the yoke valve-closing side and the outer peripheral surface of the holder press-fit portion of the valve holder mutually slide, and the load in the axial direction can be reduced. The deformation of the thinned outer diameter portion can be suppressed.
　また、隙間外径部が薄肉化され、アマチュア摺動部は薄肉化されていないので、製造バラツキにより隙間外径部が万が一変形した場合でも、アマチュア摺動部が変形することを抑制できる。よって、アマチュア摺動部とアマチュアとの摺動不良が生じることを抑制でき、燃料噴射弁の動作不良のリスクを低減することができる。また、アマチュア摺動部は、ホルダ圧入部よりも軸方向の開弁側に配置され、ヨーク閉弁側部に圧入されない。よって、アマチュア摺動部は、圧入により変形し難く、アマチュア摺動部の内周面の変形による摺動不良を生じ難くできる。 Further, since the gap outer diameter portion is thinned and the armature sliding portion is not thinned, it is possible to suppress deformation of the armature sliding portion even if the gap outer diameter portion is deformed by manufacturing variation. Therefore, it is possible to suppress the occurrence of the sliding failure between the armature sliding portion and the armature, and it is possible to reduce the risk of the malfunction of the fuel injection valve. Further, the armature sliding portion is disposed closer to the valve opening side in the axial direction than the holder press-in portion, and is not press-fitted to the yoke closed side. Therefore, the armature sliding portion is unlikely to be deformed by press-fitting, and it is possible to make it difficult to cause a sliding failure due to the deformation of the inner circumferential surface of the armature sliding portion.
本発明の実施の形態１に係る燃料噴射弁の断面図である。It is a sectional view of a fuel injection valve concerning Embodiment 1 of the present invention. 本発明の実施の形態１に係る燃料噴射弁の要部断面図である。It is principal part sectional drawing of the fuel injection valve concerning Embodiment 1 of this invention. 本発明の実施の形態１に係る弁リフト量の調節を説明するための燃料噴射弁の断面図である。It is sectional drawing of the fuel injection valve for demonstrating adjustment of the valve lift amount which concerns on Embodiment 1 of this invention. 本発明の実施の形態１に係るヨークの加工を説明するための断面図である。It is sectional drawing for demonstrating the process of the yoke which concerns on Embodiment 1 of this invention. 本発明の実施の形態１に係るヨークの加工を説明するための断面図である。It is sectional drawing for demonstrating the process of the yoke which concerns on Embodiment 1 of this invention. 本発明の実施の形態１に係るヨーク閉弁側部のシェービング加工を説明するための断面図である。It is sectional drawing for demonstrating the shaving process of the yoke valve closing side which concerns on Embodiment 1 of this invention.
実施の形態１．
　実施の形態１に係る燃料噴射弁１について図面を参照して説明する。図１は、本実施の形態に係る燃料噴射弁１を、軸心Ｙを通る平面で切断した断面図である。図２は、燃料噴射弁１の要部断面図である。なお、図１及び図２は、閉弁状態の燃料噴射弁１の図である。 Embodiment 1
The fuel injection valve 1 according to the first embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the fuel injection valve 1 according to the present embodiment, taken along a plane passing through the axis Y. As shown in FIG. FIG. 2 is a cross-sectional view of an essential part of the fuel injection valve 1. 1 and 2 are views of the fuel injection valve 1 in the closed state.
　燃料噴射弁１の先端部は、エンジンの吸気通路（不図示）に露出するように取り付けられ、燃料噴射弁１の後端部に燃料が供給される。燃料噴射弁１は、制御装置からの電気信号により開弁して吸気通路内に燃料を噴射する。 The front end of the fuel injection valve 1 is attached so as to be exposed to an intake passage (not shown) of the engine, and fuel is supplied to the rear end of the fuel injection valve 1. The fuel injection valve 1 is opened by an electric signal from the control device to inject fuel into the intake passage.
　燃料噴射弁１は、燃料通路３ａが形成された弁座３と、燃料通路３ａを開閉する弁体２と、を備えている。弁体２は、軸方向の開弁側Ｘ１に移動すると、弁座３と離間して燃料通路３ａを開き、軸方向の閉弁側Ｘ２に移動すると、弁座３に当接して燃料通路３ａを閉じる。弁体２は、燃料通路３ａの軸方向の開弁側Ｘ１に配置されている。弁体２は、燃料通路３ａを塞ぐ球状の先端部２ａと、先端部２ａから軸方向の開弁側Ｘ１に延出する筒状（本例では円筒状）のパイプ２ｂと、を有したニードル弁とされている。パイプ２ｂには、側面に複数の穴が設けられており、先端部２ａに溶接により固定されている。燃料噴射弁１は、弁座３の軸方向の閉弁側Ｘ２に設けられ、噴射孔４ａが形成されたオリフィスプレート４を備えている。 The fuel injection valve 1 includes a valve seat 3 in which a fuel passage 3a is formed, and a valve body 2 for opening and closing the fuel passage 3a. When the valve body 2 moves to the valve opening side X1 in the axial direction, it separates from the valve seat 3 and opens the fuel passage 3a, and when moving to the valve closing side X2 in the axial direction, it abuts on the valve seat 3 and the fuel passage 3a Close The valve body 2 is disposed on the valve opening side X1 in the axial direction of the fuel passage 3a. The valve body 2 is a needle having a spherical tip 2a for closing the fuel passage 3a and a cylindrical (cylindrical in this example) pipe 2b extending from the tip 2a to the valve opening side X1 in the axial direction. It is considered to be a valve. The pipe 2b is provided with a plurality of holes on its side surface, and is fixed to the tip 2a by welding. The fuel injection valve 1 is provided on the valve closing side X2 in the axial direction of the valve seat 3, and includes an orifice plate 4 in which injection holes 4a are formed.
　本発明において、弁体２が移動する方向を軸方向Ｘと定義する。軸方向Ｘは、各筒状部材の軸心Ｙと平行になっている。軸方向の閉弁側Ｘ２は、燃料噴射弁１の先端側であり、軸方向の開弁側Ｘ１は、燃料噴射弁１の後端側である。なお、各筒状部材は、軸心Ｙの周りに配置されている。 In the present invention, the direction in which the valve body 2 moves is defined as the axial direction X. The axial direction X is parallel to the axial center Y of each cylindrical member. The valve closing side X2 in the axial direction is the tip end side of the fuel injection valve 1, and the valve opening side X1 in the axial direction is the rear end side of the fuel injection valve 1. Each cylindrical member is disposed around the axis Y.
　燃料噴射弁１の軸方向の閉弁側Ｘ２の端部（先端部）に、弁座３、オリフィスプレート４が配置されており、燃料が噴射される。燃料噴射弁１の軸方向の開弁側Ｘ１の端部（後端部）が、軸方向の開弁側Ｘ１に開口しており、開口部に燃料管（不図示）から３００ｋＰａ程度の燃料が供給される。燃料噴射弁１の後端部の外周面にはＯリング１３が嵌め込まれており、燃料管との接続がシールされる。 The valve seat 3 and the orifice plate 4 are disposed at the end (tip) of the valve closing side X2 in the axial direction of the fuel injection valve 1, and fuel is injected. The end (rear end) of the valve opening side X1 in the axial direction of the fuel injection valve 1 opens in the valve opening side X1 in the axial direction, and fuel of about 300 kPa is received from the fuel pipe (not shown) in the opening. Supplied. An O-ring 13 is fitted on the outer peripheral surface of the rear end portion of the fuel injection valve 1, and the connection with the fuel pipe is sealed.
　燃料噴射弁１は、筒状のコイル５と、コイル５の内径側に配置された筒状のコア７と、コア７の軸方向の閉弁側Ｘ２にコア７と隙間６を空けて配置され、コイル５の通電により生じた磁束により軸方向の開弁側Ｘ１に吸引される筒状のアマチュア８と、コイル５の外側を覆う筒状のヨーク１１と、を備えている。コア７、ヨーク１１、アマチュア８は、鉄などの磁性体により構成されている。コイル５は、銅線が巻装されたボビン５ａを有している。ボビン５ａは、後述するターミナル１２の支持部材と一体形成されている。コア７は、燃料噴射弁１の軸方向の開弁側Ｘ１の端部（後端部）まで延びている。 The fuel injection valve 1 is disposed with a gap 6 at the valve closing side X2 in the axial direction of the core 7 and the cylindrical core 7 disposed on the inner diameter side of the coil 5 and the core 5. A tubular armature 8 attracted to the valve opening side X1 in the axial direction by magnetic flux generated by energization of the coil 5 and a tubular yoke 11 covering the outside of the coil 5 are provided. The core 7, the yoke 11, and the armature 8 are made of a magnetic material such as iron. The coil 5 has a bobbin 5a on which a copper wire is wound. The bobbin 5a is integrally formed with a support member of the terminal 12 described later. The core 7 extends to the end (rear end) of the valve opening side X1 of the fuel injection valve 1 in the axial direction.
　アマチュア８は、円筒状の本体部８ａと、本体部８ａから軸方向の閉弁側Ｘ２に延出した部分であって、本体部８ａと内径が同じであり本体部８ａよりも外径が小さい円筒状のボス部８ｂと、を有している。コア７（後述するコア小径部７ａ）の軸方向の閉弁側Ｘ２の端面と、アマチュア８（本体部８ａ）の軸方向の開弁側Ｘ１の端面とは、軸方向Ｘに対向している。コア７とアマチュア８との間の軸方向Ｘの隙間６は、閉弁状態で生じており、開弁状態では無くなる。本体部８ａの軸方向の閉弁側Ｘ２の部分は、軸方向の開弁側Ｘ１の部分よりも外径が大きくなっており、弁ホルダ９のアマチュア摺動部９ｃの内周面と摺動する摺動面となっている。アマチュア８の内周面は、パイプ２ｂの軸方向の開弁側Ｘ１の端部の外周面に圧入により嵌合され、固定されている。 The armature 8 is a cylindrical main body portion 8a and a portion extending from the main body portion 8a to the valve closing side X2 in the axial direction, and has the same inner diameter as the main body portion 8a and an outer diameter smaller than the main body portion 8a And a cylindrical boss 8b. The end face on the valve closing side X2 of the core 7 (core small diameter portion 7a described later) in the axial direction and the end face of the valve opening side X1 on the axial direction of the armature 8 (body portion 8a) are opposed in the axial direction X . The gap 6 in the axial direction X between the core 7 and the armature 8 occurs in the closed state, and disappears in the open state. The portion on the valve closing side X2 in the axial direction of the main body portion 8a has an outer diameter larger than the portion on the valve opening side X1 in the axial direction, and slides with the inner circumferential surface of the armature sliding portion 9c of the valve holder 9 Is a sliding surface. The inner peripheral surface of the armature 8 is press-fitted and fixed to the outer peripheral surface of the end of the valve opening side X1 in the axial direction of the pipe 2b.
　燃料噴射弁１は、コア７の内径側に配置され、アマチュア８を軸方向の閉弁側Ｘ２に押圧するバネ１５を備えている。バネ１５の軸方向の開弁側Ｘ１の端部は、筒状（本例では、円筒状）のロッド１６により支持され、バネ１５の軸方向の閉弁側Ｘ２の端部は、アマチュア８に固定されたパイプ２ｂを軸方向の閉弁側Ｘ２を押圧している。ロッド１６の外周面は、コア７の内周面に圧入により嵌合され、固定されている。 The fuel injection valve 1 includes a spring 15 disposed on the inner diameter side of the core 7 and pressing the armature 8 against the valve closing side X2 in the axial direction. The end of the axial valve-opening side X1 of the spring 15 is supported by a cylindrical (in this example, cylindrical) rod 16 and the end of the axial valve-closing side X2 of the spring 15 is connected to the armature 8 The fixed pipe 2b is pressed on the valve closing side X2 in the axial direction. The outer peripheral surface of the rod 16 is press-fitted and fixed to the inner peripheral surface of the core 7.
　燃料噴射弁１は、コイル５を外部の制御装置に接続するためのターミナル１２を備えている。ターミナル１２は、燃料噴射弁１の側方部分に配置されている。制御装置からターミナル１２に電力が供給されると、コイル５が磁束を発生し、コイル５の磁束によりアマチュア８を軸方向の開弁側Ｘ１に吸引する吸引力が生じる。軸方向の開弁側Ｘ１への磁束の吸引力が、軸方向の閉弁側Ｘ２へのバネ１５の押圧力を上回って、アマチュア８及び弁体２が軸方向の開弁側Ｘ１に移動し、弁体２が弁座３から離間して開弁状態となる。一方、制御装置からターミナル１２への電力供給が停止すると、軸方向の開弁側Ｘ１への磁束の吸引力がなくなり、軸方向の閉弁側Ｘ２へのバネ１５の押圧力により、アマチュア８及び弁体２が軸方向の閉弁側Ｘ２に移動し、弁体２が弁座３に当接して閉弁状態となる。 The fuel injection valve 1 comprises a terminal 12 for connecting the coil 5 to an external control device. The terminal 12 is disposed at a side portion of the fuel injection valve 1. When power is supplied from the control device to the terminal 12, the coil 5 generates a magnetic flux, and the magnetic flux of the coil 5 generates a suction force for attracting the armature 8 to the valve opening side X1 in the axial direction. The attraction force of the magnetic flux to the valve opening side X1 in the axial direction exceeds the pressing force of the spring 15 to the valve closing side X2 in the axial direction, and the armature 8 and the valve body 2 move to the valve opening side X1 in the axial direction. The valve body 2 is separated from the valve seat 3 and is in an open state. On the other hand, when the power supply from the control device to the terminal 12 is stopped, the attraction of the magnetic flux to the valve opening side X1 in the axial direction disappears, and the pressing force of the spring 15 to the valve closing side X2 in the axial direction The valve body 2 moves to the valve closing side X2 in the axial direction, and the valve body 2 abuts on the valve seat 3 to be in a valve closed state.
　燃料噴射弁１は、弁座３、弁体２、及びアマチュア８を内径側に収容した筒状の弁ホルダ９を備えている。弁ホルダ９は、オリフィスプレート４も内径側に収容している。 The fuel injection valve 1 includes a valve seat 3, a valve body 2, and a cylindrical valve holder 9 accommodating an armature 8 on the inner diameter side. The valve holder 9 also accommodates the orifice plate 4 on the inner diameter side.
　オリフィスプレート４は、弁座３の軸方向の閉弁側Ｘ２の部分に溶接された溶接部４ｃと、弁ホルダ９に溶接された溶接部４ｂと、を備えている。すなわち、弁座３は、オリフィスプレート４を介して弁ホルダ９に固定されている。 The orifice plate 4 includes a welded portion 4 c welded to a portion on the valve closing side X 2 in the axial direction of the valve seat 3 and a welded portion 4 b welded to the valve holder 9. That is, the valve seat 3 is fixed to the valve holder 9 via the orifice plate 4.
　ヨーク１１は、コイル５の外径側を覆う筒状のヨーク外径部１１ａと、ヨーク外径部１１ａから軸方向の閉弁側Ｘ２に延出し、弁ホルダ９を支持する筒状のヨーク閉弁側部１１ｂと、ヨーク外径部１１ａから軸方向の開弁側Ｘ１に延出し、コア７の外周面に溶接されたヨーク開弁側部１１ｃと、を有している。 The yoke 11 extends from the yoke outer diameter portion 11 a to the valve closing side X 2 in the axial direction, and supports the valve holder 9, and the cylindrical yoke closed to support the valve holder 9. A valve side portion 11b and a yoke open side portion 11c extending from the yoke outer diameter portion 11a to the valve opening side X1 in the axial direction and welded to the outer peripheral surface of the core 7 are provided.
　本実施の形態では、ヨーク外径部１１ａ及びヨーク閉弁側部１１ｂは、一体形成された部材であり、ヨーク外径部１１ａの径よりもヨーク閉弁側部１１ｂの径が２段階に小さくなった２段の円筒状に形成されている。ヨーク開弁側部１１ｃは、プレート状の部材であり、コア７の外周面に溶接された溶接部１１ｄと、ヨーク外径部１１ａに溶接された溶接部１１ｅと、を有している。ヨーク開弁側部１１ｃは、ターミナル１２が配置された周方向の部分を切り欠いた、円環プレート状の部材とされており、コア７の外周面とヨーク外径部１１ａの内周面との間の円筒状の空間の軸方向の開弁側Ｘ１の開口を塞ぐ。 In the present embodiment, the yoke outer diameter portion 11a and the yoke valve closing side portion 11b are integrally formed members, and the diameter of the yoke valve closing side portion 11b is smaller in two stages than the diameter of the yoke outer diameter portion 11a. It is formed in a two-step cylindrical shape. The yoke valve-opening side portion 11c is a plate-like member, and has a welded portion 11d welded to the outer peripheral surface of the core 7 and a welded portion 11e welded to the yoke outer diameter portion 11a. The yoke opening side portion 11c is a ring plate-like member in which a circumferential portion in which the terminal 12 is disposed is cut away, and the outer peripheral surface of the core 7 and the inner peripheral surface of the yoke outer diameter portion 11a Block the opening on the valve opening side X1 in the axial direction of the cylindrical space between them.
　弁ホルダ９は、内周面がコア７の外周面に嵌合され、溶接されたコア接続部９ａと、コア接続部９ａよりも軸方向の閉弁側Ｘ２の部分であって、コア７とアマチュア８との間の隙間６の外径側に配置された隙間外径部９ｂと、隙間外径部９ｂよりも軸方向の閉弁側Ｘ２の部分であって、内周面がアマチュア８（本体部８ａの軸方向の閉弁側Ｘ２の部分）の外周面と摺動するアマチュア摺動部９ｃと、アマチュア摺動部９ｃよりも軸方向の閉弁側Ｘ２の部分であって、外周面がヨーク閉弁側部１１ｂの内周面に圧入されたホルダ圧入部９ｄと、を有している。また、弁ホルダ９は、ホルダ圧入部９ｄよりも軸方向の閉弁側Ｘ２の部分であって、内径側に弁座３、弁体２、及びオリフィスプレート４を収容しているホルダ先端部９ｅを有している。 The valve holder 9 has a core connecting portion 9a whose inner peripheral surface is fitted to the outer peripheral surface of the core 7 and a portion on the valve closing side X2 in the axial direction of the core connecting portion 9a. The inner circumferential surface of the gap outer diameter portion 9b disposed on the outer diameter side of the gap 6 between the armature 8 and the valve closing side X2 in the axial direction with respect to the gap outer diameter portion 9b The armature sliding portion 9c sliding on the outer peripheral surface of the axial closing side X2 of the main body portion 8a and the valve closing side X2 in the axial direction with respect to the armature sliding portion 9c And the holder press-fit portion 9d press-fit into the inner peripheral surface of the yoke valve-closing side portion 11b. Further, the valve holder 9 is a portion on the valve closing side X2 in the axial direction with respect to the holder press-fit portion 9d, and is a holder tip portion 9e accommodating the valve seat 3, the valve body 2 and the orifice plate 4 on the inner diameter side. have.
　アマチュア摺動部９ｃの外径は、ホルダ圧入部９ｄの外径よりも小さくされており、アマチュア摺動部９ｃの外周面は、ヨーク閉弁側部１１ｂの内周面に接しないで、圧入されないように構成されている。 The outer diameter of the armature sliding portion 9c is smaller than the outer diameter of the holder press-in portion 9d, and the outer peripheral surface of the armature sliding portion 9c is not press-contacted with the inner peripheral surface of the yoke valve closing side 11b. It is configured not to be.
　コア７の軸方向の閉弁側Ｘ２の端部は、開弁側Ｘ１の部分よりも外径が小さくなった円筒状のコア小径部７ａとなっており、コイル５（ボビン５ａ）の内周面とコア小径部７ａの外周面との間には、軸方向の閉弁側Ｘ２に開口する円筒状の隙間７ｂ（以下、コア小径部隙間７ｂと称す）が生じている。このコア小径部隙間７ｂに、弁ホルダ９のコア接続部９ａが配置されている。弁ホルダ９のコア接続部９ａは円筒状に形成されており、コア接続部９ａの内周面が、コア小径部７ａの外周面に圧入により嵌合された状態で、溶接部９ｆによりコア接続部９ａがコア小径部７ａに溶接されている。 The end of the axial valve closing side X2 of the core 7 is a cylindrical core small diameter portion 7a whose outer diameter is smaller than that of the valve opening side X1, and the inner periphery of the coil 5 (bobbin 5a) Between the surface and the outer peripheral surface of the core small diameter portion 7a, a cylindrical gap 7b (hereinafter referred to as the core small diameter portion clearance 7b) which is opened on the valve closing side X2 in the axial direction is generated. The core connecting portion 9a of the valve holder 9 is disposed in the core small diameter portion gap 7b. The core connection portion 9a of the valve holder 9 is formed in a cylindrical shape, and the core connection is performed by the weld portion 9f in a state where the inner peripheral surface of the core connection portion 9a is fitted to the outer peripheral surface of the core small diameter portion 7a by press fitting. The portion 9a is welded to the core small diameter portion 7a.
＜隙間外径部９ｂの薄肉化とその課題＞
　隙間外径部９ｂは、コア接続部９ａ、アマチュア摺動部９ｃ、及びホルダ圧入部９ｄよりも薄肉に形成されている。すなわち、隙間外径部９ｂの径方向の厚みは、コア接続部９ａ、アマチュア摺動部９ｃ、及びホルダ圧入部９ｄの径方向の厚みよりも薄く形成されている。薄肉化により隙間外径部９ｂを通る磁束を減少させ、コア７とアマチュア８との間の隙間６を通る磁束を増加させ、アマチュア８の吸引力を増加させることができる。 <Thin thickness reduction of the gap outer diameter portion 9b and its problems>
The gap outer diameter portion 9b is thinner than the core connection portion 9a, the armature sliding portion 9c, and the holder press-fit portion 9d. That is, the radial thickness of the gap outer diameter portion 9b is smaller than the radial thickness of the core connection portion 9a, the armature sliding portion 9c, and the holder press-fit portion 9d. By thinning, the magnetic flux passing through the gap outer diameter portion 9b can be reduced, the magnetic flux passing through the gap 6 between the core 7 and the armature 8 can be increased, and the attraction of the armature 8 can be increased.
　しかし、隙間外径部９ｂを薄肉化すると、隙間外径部９ｂが変形し易くなる。隙間外径部９ｂよりも軸方向の開弁側Ｘ１の部分と軸方向の閉弁側Ｘ２の部分とは、ヨーク１１を介して連結されており、溶接後の冷却によりヨーク１１が収縮すると、隙間外径部９ｂに軸方向Ｘの荷重がかかる。軸方向Ｘの荷重が、隙間外径部９ｂが塑性変形し始める軸方向の変形荷重Ｂを上回ると、隙間外径部９ｂが変形し、隙間６の間隔が狭くなり、開弁時のアマチュア８の軸方向の開弁側Ｘ１への移動量が減少し、開弁不良が生じる。そこで、溶接後の冷却によりヨーク１１が収縮するなどして、隙間外径部９ｂに軸方向Ｘの荷重がかかっても、隙間外径部９ｂの変形を抑制できる燃料噴射弁１が望まれる。 However, when the gap outer diameter portion 9 b is thinned, the gap outer diameter portion 9 b is easily deformed. The portion on the valve opening side X1 in the axial direction than the gap outer diameter portion 9b and the portion on the valve closing side X2 in the axial direction are connected via the yoke 11, and when the yoke 11 contracts due to cooling after welding, A load in the axial direction X is applied to the gap outer diameter portion 9 b. When the load in the axial direction X exceeds the deformation load B in the axial direction in which the gap outer diameter portion 9b starts plastic deformation, the gap outer diameter portion 9b is deformed, the gap 6 becomes narrow, and the armature 8 is opened. The amount of movement to the valve opening side X1 in the axial direction decreases, and a valve opening failure occurs. Therefore, it is desirable to provide a fuel injection valve 1 that can suppress deformation of the gap outer diameter portion 9b even if a load in the axial direction X is applied to the gap outer diameter portion 9b due to shrinkage of the yoke 11 due to cooling after welding.
＜薄肉化された隙間外径部９ｂの変形抑制＞
　本実施の形態では、隙間外径部９ｂよりも軸方向の開弁側Ｘ１では、弁ホルダ９のコア接続部９ａとコア７とが溶接部９ｆにより溶接され、コア７とヨーク１１（ヨーク開弁側部１１ｃ）とが溶接部１１ｄにより溶接されている。よって、隙間外径部９ｂよりも軸方向の開弁側Ｘ１の部分は、溶接によりヨーク１１に連結されているため、軸方向Ｘの荷重を逃がすことができない。一方、隙間外径部９ｂよりも軸方向の閉弁側Ｘ２では、弁ホルダ９のホルダ圧入部９ｄとヨーク１１（ヨーク閉弁側部１１ｂ）とが圧入により連結されている。よって、隙間外径部９ｂよりも軸方向の閉弁側Ｘ２の部分は、圧入部の面圧により生じた摩擦力Ａによりヨーク１１に連結されているため、圧入部が相互に滑ることにより、軸方向Ｘの荷重を逃がすことができるように構成されている。 <Restraint of deformation of thinned outer diameter portion 9b>
In the present embodiment, on the valve opening side X1 in the axial direction with respect to the gap outer diameter portion 9b, the core connecting portion 9a of the valve holder 9 and the core 7 are welded by the welded portion 9f, and the core 7 and the yoke 11 The valve side portion 11c) is welded by a welding portion 11d. Therefore, the portion on the valve opening side X1 in the axial direction with respect to the gap outer diameter portion 9b is connected to the yoke 11 by welding, so the load in the axial direction X can not be released. On the other hand, on the valve closing side X2 in the axial direction with respect to the gap outer diameter portion 9b, the holder press-fit portion 9d of the valve holder 9 and the yoke 11 (yoke valve closing side portion 11b) are connected by press fitting. Therefore, the portion on the valve closing side X2 in the axial direction with respect to the gap outer diameter portion 9b is connected to the yoke 11 by the frictional force A generated by the surface pressure of the press-fit portion. The load in the axial direction X can be released.
　そこで、ヨーク１１のヨーク閉弁側部１１ｂの内周面と弁ホルダ９のホルダ圧入部９ｄの外周面との間に生じる軸方向Ｘの摩擦力Ａは、弁ホルダ９の隙間外径部９ｂが塑性変形し始める軸方向の変形荷重Ｂよりも小さくされている（Ａ＜Ｂ）。 Therefore, the frictional force A in the axial direction X generated between the inner peripheral surface of the yoke valve-closing side 11b of the yoke 11 and the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 is the clearance outer diameter portion 9b of the valve holder 9. Is smaller than the axial deformation load B at which the plastic deformation starts (A <B).
　この構成によれば、溶接後のヨーク１１の収縮等により、隙間外径部９ｂにかかる軸方向Ｘの荷重が、隙間外径部９ｂの変形荷重Ｂに到達する前に、ヨーク閉弁側部１１ｂの内周面と弁ホルダ９のホルダ圧入部９ｄの外周面とが相互に滑り、軸方向Ｘの荷重を減少させることができ、隙間外径部９ｂの変形を抑制できる。 According to this configuration, before the load in the axial direction X applied to the gap outer diameter portion 9b reaches the deformation load B of the gap outer diameter portion 9b due to contraction or the like of the yoke 11 after welding, the yoke valve closing side portion The inner peripheral surface 11b and the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 mutually slide to reduce the load in the axial direction X, and the deformation of the gap outer diameter portion 9b can be suppressed.
　また、上記のように、隙間外径部９ｂが薄肉化され、アマチュア摺動部９ｃは薄肉化されていないので、製造バラツキにより隙間外径部９ｂが万が一変形した場合でも、アマチュア摺動部９ｃが変形することを抑制できる。よって、アマチュア摺動部９ｃとアマチュア８（本体部８ａの軸方向の閉弁側Ｘ２の部分）との摺動不良が生じることを抑制でき、燃料噴射弁１の動作不良のリスクを低減することができる。 Further, as described above, since the gap outer diameter portion 9b is thinned and the armature sliding portion 9c is not thinned, the armature sliding portion 9c is formed even if the gap outer diameter portion 9b is deformed due to manufacturing variations. Can be suppressed from being deformed. Therefore, it is possible to suppress the occurrence of a sliding failure between the armature sliding portion 9c and the armature 8 (portion on the valve closing side X2 in the axial direction of the main body portion 8a), and to reduce the risk of operation failure of the fuel injection valve 1. Can.
　また、上記のように、アマチュア摺動部９ｃは、ホルダ圧入部９ｄよりも軸方向の開弁側Ｘ１に配置され、ヨーク閉弁側部１１ｂに圧入されない。よって、アマチュア摺動部９ｃは、圧入により変形し難く、アマチュア摺動部９ｃの内周面の変形による摺動不良が生じ難くできる。 Further, as described above, the armature sliding portion 9c is disposed closer to the valve opening side X1 in the axial direction than the holder press-fit portion 9d, and is not press-fitted to the yoke closed side 11b. Therefore, the armature sliding portion 9c is difficult to be deformed by press-fitting, and the sliding failure due to the deformation of the inner peripheral surface of the armature sliding portion 9c is unlikely to occur.
　本実施の形態では、隙間外径部９ｂからアマチュア摺動部９ｃまでの弁ホルダ９の内周面は、同一径の円筒面とされている。この構成によれば、隙間外径部９ｂとアマチュア摺動部９ｃとの内径が同時に管理されるため、アマチュア摺動部９ｃと同様に、隙間外径部９ｂの内径を高精度に管理し、隙間外径部９ｂの変形荷重Ｂのバラツキを抑制することができる。 In the present embodiment, the inner peripheral surface of the valve holder 9 from the gap outer diameter portion 9b to the armature sliding portion 9c is a cylindrical surface having the same diameter. According to this configuration, since the inner diameters of the gap outer diameter portion 9b and the armature sliding portion 9c are simultaneously managed, the inner diameter of the gap outer diameter portion 9b is managed with high accuracy, similarly to the armature sliding portion 9c, It is possible to suppress the variation in the deformation load B of the gap outer diameter portion 9b.
＜燃料噴射弁１の組み立て＞
　まず、弁ホルダ９のコア接続部９ａの内周面に、コア７のコア小径部７ａの外周面を圧入し、その後、コア接続部９ａとコア小径部７ａとを溶接して溶接部９ｆを形成する。 <Assembly of Fuel Injection Valve 1>
First, the outer peripheral surface of the core small diameter portion 7a of the core 7 is press-fit into the inner peripheral surface of the core connecting portion 9a of the valve holder 9, and then the core connecting portion 9a and the core small diameter portion 7a are welded to form a welded portion 9f. Form.
　そして、コア７と一体化された弁ホルダ９のホルダ圧入部９ｄの外周面を、ヨーク外径部１１ａと一体形成されたヨーク閉弁側部１１ｂの内周面に圧入する。そして、ターミナル１２と一体形成されたコイル５を、コア７の外周面とヨーク外径部１１ａの内周面との間の円筒状の空間に挿入する。そして、ターミナル１２部分が欠けた円環プレート状のヨーク開弁側部１１ｃを、円筒状の空間の軸方向の開弁側Ｘ１の開口部に配置し、ヨーク外径部１１ａとヨーク開弁側部１１ｃとの境界を溶接して溶接部１１ｅを形成し、コア７とヨーク開弁側部１１ｃとの境界を溶接して溶接部１１ｄを形成する。 Then, the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 integrated with the core 7 is press-fit into the inner peripheral surface of the yoke valve closing side 11b integrally formed with the yoke outer diameter portion 11a. Then, the coil 5 integrally formed with the terminal 12 is inserted into a cylindrical space between the outer peripheral surface of the core 7 and the inner peripheral surface of the yoke outer diameter portion 11a. Then, an annular plate-like yoke valve-opened side portion 11c in which the terminal 12 portion is cut out is disposed at the opening of the valve-opening side X1 in the axial direction of the cylindrical space, and the yoke outer diameter portion 11a and the yoke valve-opened side The boundary with the portion 11c is welded to form a welded portion 11e, and the boundary between the core 7 and the yoke opening side 11c is welded to form a welded portion 11d.
　コア７とヨーク開弁側部１１ｃとの溶接の際に、レーザー照射によりコア７とヨーク開弁側部１１ｃの一部が金属溶融し、周囲の金属の温度が上昇する。レーザー照射が終了すると、溶融した金属の凝固、温度降下による金属の収縮により、コア７に対してヨーク１１を軸方向の開弁側Ｘ１に移動させるような応力が発生する。この時、上述したように、ヨーク１１のヨーク閉弁側部１１ｂの内周面と弁ホルダ９のホルダ圧入部９ｄの外周面とが相互に滑り、薄肉化された弁ホルダ９の隙間外径部９ｂにかかる軸方向Ｘの荷重が、変形荷重Ｂに到達することを抑制でき、隙間外径部９ｂの変形を抑制できる。 At the time of welding of the core 7 and the yoke valve-opening side 11c, a part of the core 7 and the yoke valve-opening side 11c is melted by laser irradiation, and the temperature of the surrounding metal rises. When the laser irradiation ends, solidification of the molten metal and contraction of the metal due to temperature drop generate stress that moves the yoke 11 to the open side X1 in the axial direction with respect to the core 7. At this time, as described above, the inner peripheral surface of the yoke closed valve side portion 11b of the yoke 11 and the outer peripheral surface of the holder press-fit portion 9d of the valve holder 9 mutually slide, and the gap outer diameter of the thinned valve holder 9 The load in the axial direction X applied to the portion 9 b can be prevented from reaching the deformation load B, and the deformation of the gap outer diameter portion 9 b can be suppressed.
　そして、組み立てた上記部品に対して、樹脂１８をモールディングする。そして、コア７の内周面にロッド１６の外周面を圧入する。そして、バネ１５、パイプ２ｂに圧入されたアマチュア８、及び弁体２を、コア７及び弁ホルダ９の内側に挿入する。溶接部４ｃにより互いに溶接されたオリフィスプレート４及び弁座３を、弁ホルダ９の内側に挿入し、弁ホルダ９に対して位置決めした後、オリフィスプレート４の外周部と弁ホルダ９の内周面とを全周に亘って溶接して溶接部４ｂを形成する。 Then, the resin 18 is molded on the assembled parts. Then, the outer peripheral surface of the rod 16 is pressed into the inner peripheral surface of the core 7. Then, the spring 15, the armature 8 pressed into the pipe 2 b, and the valve body 2 are inserted into the core 7 and the valve holder 9. After the orifice plate 4 and the valve seat 3 welded to each other by the welding portion 4 c are inserted into the inside of the valve holder 9 and positioned relative to the valve holder 9, the outer peripheral portion of the orifice plate 4 and the inner peripheral surface of the valve holder 9 Are welded all around to form a welded portion 4b.
　次に、図３に示すように、燃料噴射弁１の軸方向の開弁側Ｘ１の端部（後端部）を固定した状態で、円柱状の治具１９により、オリフィスプレート４を軸方向の開弁側Ｘ１に押圧する。治具１９の先端は、軸方向の開弁側Ｘ１に突出した円筒状の突出部１９ａを有している。突出部１９ａが、溶接部４ｃ付近を押圧し、溶接部４ｃと溶接部４ｂとの間のオリフィスプレート４の部分を塑性変形させることにより、弁ホルダ９に対して弁座３を軸方向の開弁側Ｘ１に変位させて、コア７とアマチュア８との隙間６の軸方向Ｘの間隔を調節し、弁リフト量を調節する。 Next, as shown in FIG. 3, with the end (rear end) of the valve opening side X1 in the axial direction of the fuel injection valve 1 fixed, the orifice plate 4 is axially moved by the cylindrical jig 19. Is pressed on the valve open side X1. The tip of the jig 19 has a cylindrical protrusion 19 a that protrudes on the valve opening side X1 in the axial direction. The protrusion 19a presses the vicinity of the weld 4c and plastically deforms the portion of the orifice plate 4 between the weld 4c and the weld 4b to open the valve seat 3 in the axial direction with respect to the valve holder 9. The valve lift amount is adjusted by adjusting the distance in the axial direction X of the gap 6 between the core 7 and the armature 8 by displacing the valve side X1.
　本実施の形態では、弁ホルダ９の隙間外径部９ｂ（径方向の厚み）は、アマチュア８の吸引力を増加させるため、オリフィスプレート４（プレートの厚み）よりも薄肉化されており、弁ホルダ９の隙間外径部９ｂが塑性変形し始める軸方向の変形荷重Ｂは、オリフィスプレート４が塑性変形し始める軸方向の変形荷重Ｃよりも小さくなっている。 In the present embodiment, the gap outer diameter portion 9 b (the thickness in the radial direction) of the valve holder 9 is thinner than the orifice plate 4 (the thickness of the plate) in order to increase the suction force of the armature 8. The axial deformation load B at which the gap outer diameter portion 9b of the holder 9 starts plastic deformation is smaller than the axial deformation load C at which the orifice plate 4 starts plastic deformation.
　そのため、オリフィスプレート４を塑性変形させる治具１９の押圧力が、そのまま隙間外径部９ｂに伝達されれば、隙間外径部９ｂが変形するおそれがある。 Therefore, if the pressing force of the jig 19 for plastically deforming the orifice plate 4 is directly transmitted to the gap outer diameter portion 9b, the gap outer diameter portion 9b may be deformed.
　そこで、本実施の形態では、オリフィスプレート４が塑性変形し始める軸方向Ｘの変形荷重Ｃは、圧入されたヨーク閉弁側部１１ｂの内周面とホルダ圧入部９ｄの外周面との間に生じる軸方向Ｘの摩擦力Ａと、薄肉化された隙間外径部９ｂが塑性変形し始める軸方向Ｘの変形荷重Ｂと、の合計値よりも小さくされている（Ｃ＜Ａ＋Ｂ）。 Therefore, in the present embodiment, the deformation load C in the axial direction X at which the orifice plate 4 starts plastic deformation is between the inner peripheral surface of the yoke closed valve side portion 11b and the outer peripheral surface of the holder press-fit portion 9d. It is smaller than the sum of the frictional force A in the axial direction X and the deformation load B in the axial direction X at which the thinned outer diameter portion 9 b starts plastic deformation (C <A + B).
　この構成によれば、オリフィスプレート４の変形荷重Ｃ相当の押圧力で、治具１９によりオリフィスプレート４を押圧すれば、押圧力をヨーク閉弁側部１１ｂとホルダ圧入部９ｄとの摩擦力Ａと隙間外径部９ｂの変形荷重Ｂとの合計値により受け止めることができ、隙間外径部９ｂが変形することを抑制できる。よって、薄肉化された隙間外径部９ｂが変形することなく、オリフィスプレート４を変形させて、弁リフト量を調節することができる。 According to this configuration, when the orifice plate 4 is pressed by the jig 19 with a pressing force equivalent to the deformation load C of the orifice plate 4, the pressing force is a frictional force A between the yoke closing side 11b and the holder press-fit portion 9d. And the deformation load B of the gap outer diameter portion 9b can be received to suppress deformation of the gap outer diameter portion 9b. Therefore, the valve lift can be adjusted by deforming the orifice plate 4 without deforming the thinned outer diameter portion 9b.
　２段の円筒状に形成された一体部材であるヨーク外径部１１ａ及びヨーク閉弁側部１１ｂは、絞り加工及びシェービング加工により形成されている。具体的には、図４に示すように、先端が２段の円柱状に形成されたパンチ（不図示）により、板材をプレスして絞り加工する。その後、切削加工により、不要な部分を切断して図５の状態にする。この際、図４に示すように、下端を開口させるために、打抜き工具２０により中心部を打ち抜くが、この際、図５に示すように、ヨーク閉弁側部１１ｂの内周面に、内径が拡大した内径拡大部１１ｆが発生する。そのため、図６に示すように、削り工具２１により、ヨーク閉弁側部１１ｂの内周面を削り取り、まっすぐな円筒面にするシェービング加工を行う。その結果、ヨーク閉弁側部１１ｂは、絞り加工により形成された絞り加工部であって、シェービング加工により内周面が円筒状に形成されたシェービング加工部となる。 The yoke outer diameter portion 11a and the yoke closed valve side portion 11b which are two-step cylindrically formed integral members are formed by drawing processing and shaving processing. Specifically, as shown in FIG. 4, the plate material is pressed and drawn by a punch (not shown) whose end is formed in a cylindrical shape with two steps. Thereafter, unnecessary portions are cut by cutting, and the state shown in FIG. 5 is obtained. At this time, as shown in FIG. 4, in order to open the lower end, the central portion is punched out by the punching tool 20. At this time, as shown in FIG. An enlarged inner diameter portion 11 f is generated. Therefore, as shown in FIG. 6, the shaving process is performed to remove the inner peripheral surface of the yoke closed side portion 11b with a cutting tool 21 to make it a straight cylindrical surface. As a result, the yoke closed valve side portion 11b is a drawn portion formed by drawing, and becomes a shaving portion having an inner peripheral surface formed in a cylindrical shape by shaving.
　このように、圧入部となるヨーク閉弁側部１１ｂを、絞り加工及びシェービング加工により、安価に製作することができる。シェービング加工により、ヨーク閉弁側部１１ｂの内周面を、圧入に適したまっすぐな円筒面とすることができると共に、その内径を精度よく調節することができる。よって、圧入部の面圧、摩擦力Ａを精度よく調節することができ、隙間外径部９ｂの変形を抑制することができる。 As described above, the yoke closed side portion 11b to be the press-fit portion can be manufactured at low cost by the drawing process and the shaving process. By the shaving process, the inner peripheral surface of the yoke closed side 11b can be made a straight cylindrical surface suitable for press-fitting, and the inner diameter can be adjusted with high accuracy. Therefore, the surface pressure of the press-fit portion and the frictional force A can be accurately adjusted, and the deformation of the gap outer diameter portion 9b can be suppressed.
　なお、本発明は、その発明の範囲内において、実施の形態を適宜、変形、省略したりすることが可能である。 In the present invention, the embodiment can be appropriately modified or omitted within the scope of the invention.
１　燃料噴射弁、２　弁体、３　弁座、３ａ　燃料通路、４　オリフィスプレート、４ａ　噴射孔、５　コイル、６　隙間、７　コア、８　アマチュア、９　弁ホルダ、９ａ　コア接続部、９ｂ　隙間外径部、９ｃ　アマチュア摺動部、９ｄ　ホルダ圧入部、１１　ヨーク、１１ａ　ヨーク外径部、１１ｂ　ヨーク閉弁側部、１１ｃ　ヨーク開弁側部、Ｘ　軸方向、Ｘ１　軸方向の開弁側、Ｘ２　軸方向の閉弁側 1 fuel injection valve, 2 valve body, 3 valve seat, 3a fuel passage, 4 orifice plate, 4a injection hole, 5 coils, 6 gaps, 7 cores, 8 armatures, 8 valve holders, 9a core connection, 9b gap outer diameter Part, 9c Amateur sliding part, 9d holder press-in part, 11 yoke, 11a yoke outer diameter part, 11b yoke closed valve side part, 11c yoke open valve side part, X axis direction, X1 axial direction valve open side, X2 axis Valve closing side of direction

Claims (5)

  1. 　燃料通路が形成された弁座と、
    　軸方向の開弁側に移動し、前記弁座と離間して前記燃料通路を開く、又は軸方向の閉弁側に移動し、前記弁座に当接して前記燃料通路を閉じる弁体と、
    　筒状のコイルと、
    　前記コイルの内径側に配置された筒状のコアと、
    　前記コアの軸方向の閉弁側に前記コアと隙間を空けて配置され、前記コイルの通電により生じた磁束により軸方向の開弁側に吸引され、前記弁体を軸方向の開弁側に移動させる筒状のアマチュアと、
    　前記弁座、前記弁体、及び前記アマチュアを内径側に収容した筒状の弁ホルダと、
    　前記コイルの外側を覆う筒状のヨークと、を備え、
    　前記ヨークは、前記コイルの外径側を覆う筒状のヨーク外径部と、前記ヨーク外径部から軸方向の閉弁側に延出した筒状のヨーク閉弁側部と、前記ヨーク外径部から軸方向の開弁側に延出し、前記コアの外周面に溶接されたヨーク開弁側部と、を有し、
    　前記弁ホルダは、内周面が前記コアの外周面に嵌合され、溶接されたコア接続部と、前記コア接続部よりも軸方向の閉弁側の部分であって、前記コアと前記アマチュアとの間の前記隙間の外径側に配置された隙間外径部と、前記隙間外径部よりも軸方向の閉弁側の部分であって、内周面が前記アマチュアの外周面と摺動するアマチュア摺動部と、前記アマチュア摺動部よりも軸方向の閉弁側の部分であって、外周面が前記ヨーク閉弁側部の内周面に圧入されたホルダ圧入部と、を有し、
    　前記隙間外径部は、前記コア接続部、前記アマチュア摺動部、及び前記ホルダ圧入部よりも薄肉に形成され、
    　前記ヨーク閉弁側部の内周面と前記ホルダ圧入部の外周面との間に生じる軸方向の摩擦力は、前記隙間外径部が塑性変形し始める軸方向の変形荷重よりも小さい燃料噴射弁。     A valve seat having a fuel passage formed therein;
    A valve element which moves to the valve opening side in the axial direction and separates from the valve seat to open the fuel passage, or moves to the valve closing side in the axial direction, and abuts on the valve seat to close the fuel passage;
    With a cylindrical coil,
    A cylindrical core disposed on the inner diameter side of the coil;
    The core is disposed on the valve closing side in the axial direction with a gap from the core, and is attracted to the valve opening side in the axial direction by magnetic flux generated by energization of the coil, and the valve body is opened on the axial direction With tubular amateur to move,
    A cylindrical valve holder containing the valve seat, the valve body, and the armature on the inner diameter side;
    And a cylindrical yoke covering the outside of the coil,
    The yoke includes a cylindrical yoke outer diameter portion covering the outer diameter side of the coil, a cylindrical yoke closed valve side portion extending from the yoke outer diameter portion to the valve closing side in the axial direction, and the yoke outer side A yoke opening side extending from the radial portion to the valve opening side in the axial direction and welded to the outer peripheral surface of the core;
    The valve holder has a core connection portion having an inner peripheral surface fitted to the outer peripheral surface of the core and welded, and a portion on the valve closing side in the axial direction with respect to the core connection portion, the core and the armature A gap outer diameter portion disposed on the outer diameter side of the gap and a portion on the valve closing side in the axial direction with respect to the gap outer diameter portion, the inner circumferential surface being in sliding contact with the outer circumferential surface of the armature A moving armature sliding portion; and a holder press-in portion which is a portion on the valve closing side in the axial direction with respect to the armature sliding portion and whose outer peripheral surface is press-fit into the inner peripheral surface of the yoke valve closing side. Have
    The gap outer diameter portion is formed to be thinner than the core connection portion, the armature sliding portion, and the holder press-fit portion.
    The axial friction force generated between the inner peripheral surface of the yoke closed portion and the outer peripheral surface of the holder press-fit portion is smaller than the axial deformation load at which the gap outer diameter portion starts plastic deformation. valve.
  2. 　噴射孔が形成されたオリフィスプレートを更に備え、
    　前記オリフィスプレートは、前記弁座の軸方向の閉弁側の部分に溶接された溶接部と、前記弁ホルダに溶接された溶接部と、を備え、前記弁座は、前記オリフィスプレートを介して前記弁ホルダに固定され、
    　前記オリフィスプレートが塑性変形し始める軸方向の変形荷重は、前記ヨーク閉弁側部の内周面と前記ホルダ圧入部の外周面との間に生じる軸方向の摩擦力と、前記隙間外径部が塑性変形し始める軸方向の変形荷重と、の合計値よりも小さい請求項１に記載の燃料噴射弁。     It further comprises an orifice plate in which injection holes are formed,
    The orifice plate includes a welded portion welded to a portion on the valve closing side in the axial direction of the valve seat, and a welded portion welded to the valve holder, and the valve seat is inserted through the orifice plate. Fixed to the valve holder,
    The axial deformation load in which the orifice plate starts to plastically deform is an axial friction force generated between the inner peripheral surface of the yoke valve closing side and the outer peripheral surface of the holder press-fit portion, and the clearance outer diameter portion The fuel injection valve according to claim 1, which is smaller than a total value of an axial deformation load at which the plastic deformation starts to be deformed.
  3. 　前記隙間外径部が塑性変形し始める軸方向の変形荷重は、前記オリフィスプレートが塑性変形し始める軸方向の変形荷重よりも小さい請求項２に記載の燃料噴射弁。 3. The fuel injection valve according to claim 2, wherein an axial deformation load at which the gap outer diameter portion starts plastic deformation is smaller than an axial deformation load at which the orifice plate starts plastic deformation.
  4. 　前記ヨーク外径部及び前記ヨーク閉弁側部は、一体形成された部材であり、前記ヨーク外径部の径よりも前記ヨーク閉弁側部の径が２段階に小さくなった２段の円筒状に形成され、前記ヨーク閉弁側部は、絞り加工により形成された絞り加工部であって、シェービング加工により内周面が円筒状に形成されたシェービング加工部であり、
    　前記ヨーク開弁側部は、プレート状の部材であり、前記コアの外周面に溶接された溶接部と、前記ヨーク外径部に溶接された溶接部と、を有する請求項１から３のいずれか一項に記載の燃料噴射弁。     The yoke outer diameter portion and the yoke valve closing side portion are integrally formed members, and the diameter of the yoke valve closing side portion is smaller in two steps than the diameter of the yoke outer diameter portion. The yoke closed side portion is a drawn portion formed by drawing, and the inner peripheral surface is formed into a cylindrical shape by shaving.
    The yoke opening side portion is a plate-like member, and has a welded portion welded to the outer peripheral surface of the core and a welded portion welded to the yoke outer diameter portion. The fuel injection valve according to any one of the preceding claims.
  5. 　前記隙間外径部から前記アマチュア摺動部までの前記弁ホルダの内周面は、同一径の円筒面である請求項１から４のいずれか一項に記載の燃料噴射弁。 The fuel injection valve according to any one of claims 1 to 4, wherein the inner peripheral surface of the valve holder from the clearance outer diameter portion to the armature sliding portion is a cylindrical surface having the same diameter.
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