JP3944158B2 - Electromagnetic fuel injection valve - Google Patents

Description

  In the present invention, a coil assembly comprising a bobbin and a coil wound around the valve housing having a fuel injection hole at one end and a fuel inlet tube at the other end is disposed. The present invention relates to an improvement in an electromagnetic fuel injection valve in which a synthetic resin covering for covering these is formed on the outer periphery, and a pair of coil terminal plates connected to both ends of the coil are embedded in the covering.

Conventionally, as such an electromagnetic fuel injection valve, (1) a coupler terminal plate is connected to a coil terminal plate, and a coupler for housing and holding the coupler terminal plate is integrally formed on one side of the covering (patent (Refer to Document 1) and (2) A coil terminal plate is bent into a saddle shape so as to protrude to the side of the cover, and a lead wire connected to the coupler is connected to the bent end (see Patent Document 2) It is known.
Japanese Patent Laid-Open No. 8-100131 Japanese Patent Laid-Open No. 8-100732

  By the way, in the above (1), since the coupler protrudes to one side of the covering body, the shapes of the covering body and the coupler are complicated and it is difficult to integrally form them, and in the electromagnetic fuel injection valve, The generated opening / closing sound of the valve portion resonates in the coupler, which tends to be annoying noise and leak outside. In addition, the coupler is an obstacle to reducing the diameter of the fuel injection valve.

  On the other hand, in the case of (2) above, since the coupler is not provided on the covering, noise problems are unlikely to occur. On the other hand, the outer end of the coil terminal protruding from the covering is bent. This complicates the molding die structure and prevents the fuel injection valve from becoming smaller in diameter.

  The present invention has been made in view of such circumstances, and it is difficult to generate noise, and the coil terminal plate can simplify the mold structure for molding the cover, and at the same time, the diameter can be reduced. An object of the present invention is to provide the electromagnetic fuel injection valve.

  In order to achieve the above object, the present invention provides a coil assembly comprising a bobbin and a coil wound around the outer periphery of a valve housing having a fuel injection hole at one end and a fuel inlet tube at the other end. An electromagnetic fuel in which a synthetic resin covering for covering the valve housing and the coil assembly is formed and a pair of coil terminal plates connected to both ends of the coil are embedded in the covering. In the injection valve, the two coil terminal plates are arranged in a straight line parallel to the axis of the valve housing, and the outer end portions of the coil terminal plates are formed in the intermediate portion in the axial direction of the covering body. Exposed from the stepped part facing the tube side, and connected to the outer end of these coil terminal plates is the other end of a pair of connector plates arranged in parallel with the axis of the valve housing by connecting one end to a conductor. , At the outer end of the conductor That connects the coupler to the first feature.

  According to the present invention, in addition to the first feature, a first connection piece for caulking the conductor is provided at one end of the connector plate, and the coil terminal plate is caulked at the other end. A second feature is that a second connection piece for electrodeposition is provided.

  Furthermore, in addition to the first or the second feature, the present invention provides a synthetic resin connection portion cover for covering each connection portion between the connector plate, the coil terminal plate, and the conductive wire. A third feature is that the connecting portion is embedded with an insulating resin placed in close contact with the side surface and potted in the connecting portion cover, and the connecting portion cover is bonded to the covering.

  Furthermore, in addition to any one of the first to third features, the present invention further includes an engaging wall that intervenes between the connector plates and the cover from the outside of the connector plates on the connection portion cover. A fourth feature is that a guide portion is formed on one side of the covering body so that these engaging walls are slidably engaged in the axial direction.

  The guide portion corresponds to a guide convex portion 69 in an embodiment of the present invention described later.

  Furthermore, in addition to any of the first to fourth characteristics, the present invention has a fifth characteristic that a partition wall is formed integrally on the connection portion cover so as to intervene between the two connector plates.

  According to the first feature of the present invention, the coil terminal plate embedded in the covering is arranged linearly in parallel with the axis of the valve housing, so that the mold can be released during molding. This can be performed along the axial direction of the valve housing without being obstructed by the coil terminal plate, and can thus contribute to the simplification of the molding die structure.

  In addition, the connection between the coil terminal plate and the connector plate can be easily performed by caulking, electrodeposition or the like, which contributes to the improvement of productivity. In addition, like the coil terminal plate, the connector plate is also arranged parallel to the axis of the valve housing, so that these do not become large protrusions outward from the cover, so the diameter of the electromagnetic fuel injection valve can be sufficiently reduced. Can be aimed at.

  Further, since the coupler is connected to the outer end of the conducting wire connected to the connector, it does not serve as a resonance box for operating noise in the electromagnetic fuel injection valve, so that the quietness of the electromagnetic fuel injection valve can be ensured.

  Further, according to the second feature of the present invention, a connector plate with a conducting wire can be efficiently and mass produced by connecting the conducting wire to the first connecting piece of the connector plate in advance, and the connector plate can be efficiently produced. The second connection piece is crimped and temporarily fixed to the coil terminal plate, and then electrodeposited, so that the connector plate and the coil terminal plate can be connected with high accuracy and efficiency even in the vicinity of the covering. It can contribute to the improvement of productivity.

  Furthermore, according to the third feature of the present invention, a potting cavity for accommodating the connector plate can be easily obtained by arranging the connecting portion cover made of synthetic resin in close contact with the step portion and the side surface of the covering body. In addition, by potting insulating resin in this potting cavity, it is possible to improve the waterproof, dustproof and insulating properties of each connection part between the connector plate, the coil terminal plate and the conductor, and to prevent disconnection, The connection portion cover can be adhered to the covering.

  Furthermore, according to the fourth feature of the present invention, the connector plate and the guide portion of the covering body serve as a guide rail of the connection portion cover, so that the connection portion cover can be easily and accurately positioned at a position where it abuts the stepped portion. Can be guided to. Moreover, due to the engagement between the connection portion cover and the cover, leakage of potting resin from the connection portion cover can be prevented.

  Furthermore, according to the fifth feature of the present invention, the insulating property between the two connector plates can be further enhanced by an extremely simple structure in which a partition wall intervening between the two connector plates is formed in the connection portion cover.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  1 is a side view of an in-cylinder fuel injection device for an internal combustion engine according to a first embodiment of the present invention, FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1, FIG. 3 is a sectional view taken along line 3-3 in FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, FIG. 5 is an enlarged view of 5 part of FIG. 4, FIG. 6 is an enlarged view of 6 part of FIG. 9 is a cross-sectional view taken along line 8-8, FIG. 9 is a view taken along arrow 9 of the fuel injection valve in FIG. 6, FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. Is a perspective view of the backup ring in FIG. 6, FIG. 13 is a longitudinal sectional view of the seal ring in FIG. 7, FIG. 14 is a perspective view of the conductor protecting member of FIG. 7, and FIG. 16 is a view corresponding to FIG. 4 showing a second embodiment of the present invention, and FIG. 17 is an enlarged view of a portion 17 in FIG.

  First, the description starts with the description of the first embodiment of the present invention shown in FIGS.

  1 and 2, the in-cylinder fuel injection device of the present invention includes a fuel distribution pipe D attached to the outer surface of a cylinder head 1 of an electric ignition type multi-cylinder internal combustion engine E, and a plurality of branch pipes 6 of the fuel distribution pipe D. , 6... Are suspended by fuel injection pipes 2, 2... And a plurality of injection valve protection cylinders 3, 3. The injection valve protection cylinders 3, 3,... Are attached to the cylinder head 1 of the internal combustion engine E corresponding to each cylinder.

  The fuel distribution pipe D includes a cylindrical distribution pipe body 5 and the same number of branch pipes 6, 6... Extending from the distribution pipe body 5 as the injection valve protection cylinder 3. The inner volume is sufficiently larger than each branch pipe 6. The distribution pipe body 5 is provided with a plurality of brackets 7, 7... Which are fixed to a plurality of attachment portions 8 formed on the outer surface of the cylinder head 1 with bolts 9, 9.

  The branch pipe 6 and the fuel introduction pipe 2 are connected to each other by bolting the upper connecting flange 100 and the lower connecting flange 101 formed on them, and the inside is connected to each other. This will be described in detail later.

  A fuel supply pipe 10 connected to a discharge port of a fuel pump (not shown) is connected to one end of the distribution pipe body 5. A relief valve 11 is attached to one side of the distribution pipe body 5, and a fuel return pipe 12 for returning excess fuel to a fuel tank (not shown) is connected to one end of the relief valve 11.

  3 and 4, the cylinder head 1 of the internal combustion engine E is provided with a guide portion 17 extending from the center of the ceiling of the combustion chamber 15 corresponding to each cylinder to above the valve operating chamber 16. The guide portion 17 has a guide cap 18 screwed into the cylinder head 1 with its tip facing the combustion chamber 15, and a guide hole 19 formed in the cylinder head 1 so that the guide cap 18 can be inserted. And a guide cylinder 20 that has an inner peripheral surface that is continuous with the inner peripheral surface of the guide hole 19 and that is press-fitted into the cylinder head 1 and extends above the valve operating chamber 16. The guide cap 18 has a plate-like flange 18a at the upper end thereof, and the screwing depth of the guide cap 18 to the cylinder head 1 is regulated by contacting the cylinder head 1 on the lower surface of the outer periphery of the plate-like flange. Is done. Further, the guide cap 18 has a radially inward flange 18 b at the lower end opening to the combustion chamber 15. The injection valve protection cylinder 3 is fitted into the guide portion 17 thus configured.

  Next, the configuration of the electromagnetic fuel injection valve I housed and held in the injection valve protection cylinder 3 will be described with reference to FIGS.

  The valve housing 21 of the electromagnetic fuel injection valve I includes a cylindrical valve seat member 22 and a connecting cylinder that is press-fitted to the outer periphery of a flange 22a formed at the upper end of the valve seat member 22 and is laser welded W1. An annular lower yoke 24 having a portion 24 a, a nonmagnetic collar 25 coupled to the upper end of the lower yoke 24, and a fixed core 26 coupled to the upper end of the nonmagnetic collar 25, and the valve seat member 22. Between the lower yoke 24 and the lower yoke 24, a stopper plate 27 that is press-fitted into the inner peripheral surface of the connecting cylinder portion 24a is sandwiched. At the lower end portion of the fixed core 26, a press-fit portion 26 a that is press-fitted into the inner peripheral surface of the upper end portion of the nonmagnetic collar 25 and a contact surface 26 b that abuts the upper end surface of the nonmagnetic collar 25 are formed. After the press-fitting, the fixed core 26 is liquid-tightly coupled by laser welding W6 in which the outer peripheral edge portions of the abutting surfaces extend over the entire circumference. An annular protrusion 24b that contacts the lower end surface of the nonmagnetic collar 25 is integrally formed on the inner peripheral side of the upper end surface of the lower yoke 24. The outer peripheral edge of the contact surface of the annular protrusion 24b and the nonmagnetic collar 25 is , And are liquid-tightly coupled to each other by laser welding W7 over the entire circumference.

  Thus, by previously integrating the fixed core 26 and the nonmagnetic collar 25 by press-fitting, the positioning of the fixed core 26, the nonmagnetic collar 25 and the lower yoke 24 is facilitated, and the three-part welding is welded. , Can be done accurately. In particular, an annular protrusion 24b that contacts the front end surface of the nonmagnetic collar 25 is formed at the rear end portion of the lower yoke 24, and the outer peripheral edge portions of the annular protrusion 24b and the contact surface of the nonmagnetic collar 25 are welded to each other. Therefore, the contact portion between the nonmagnetic collar 25 and the fixed core 26 and the contact portion between the annular protrusion 24b and the nonmagnetic collar 25 can be welded simultaneously by laser welding from the outside in the radial direction. It can contribute to the improvement of sex.

  The valve seat member 22 includes a fuel injection hole 23 opened at a lower end surface thereof, a conical valve seat 28 connected to the inner end of the fuel injection hole 23, and a cylindrical valve connected to a large diameter portion of the valve seat 28. A guide hole 29 is provided, and a swirl collar 30 is press-fitted into the lower portion of the valve guide hole 29. An axial through groove 31 and a swirl groove 32 inclined in a fixed direction with respect to the radial line are respectively provided on the outer peripheral surface and the lower end surface of the swirl collar 30. The swirl groove 32 imparts a swirl in a certain direction to the passing fuel.

  A needle valve 33 that cooperates with the valve seat 28 is accommodated in the valve seat member 22. The needle valve 33 extends vertically through the stopper plate 27 and the swirl collar 30 and is seated on the valve seat 28. The needle valve 33 is formed on the outer periphery of the needle 34 so as to cover the inner peripheral surface of the guide hole 19. A pair of slidable journals 35 and 35 and a stopper flange 36 facing the lower surface of the stopper plate 27, and the stopper flange 36 comes into contact with the lower surface of the stopper plate 27, thereby The valve opening stroke of the needle valve 33 is restricted. Each journal 35, 35 has a plurality of flat portions on the outer periphery that allow fuel to flow in the guide hole 19.

  A movable core 37 facing the lower end surface of the fixed core 26 inside the lower yoke 24 and the nonmagnetic collar 25 is integrally connected to the upper end portion of the needle 34. The movable core 37 can move up and down in the lower yoke 24 and the nonmagnetic collar 25 without contacting the inner peripheral surfaces thereof.

  The connecting structure of the needle 34 and the movable core 37 will be described in detail. The movable core 37 is provided with a bag-like connecting hole 38 that opens at the lower end surface thereof. 34a is press-fitted. A chamfer 39 that guides the press-fitting of the head 34a into the connection hole 38 is formed on the outer periphery of the upper end of the head 34a.

  The depth of the bag-like connecting hole 38 is adjusted by adjusting the distance L1 from the upper surface of the stopper flange 36 to the upper end surface of the movable core 37 by adjusting the press-fitting depth of the head 34a into the connecting hole 38. Is set to a sufficient size. Therefore, the inner end surface of the bag-like connecting hole 38 and the tip end surface of the head portion 34a do not contact each other, and there is an adjustment for adjusting the press-fitting depth of the head portion 34a into the connecting hole 38 between them. A gap 40 is provided. The distance L1 is from the distance L2 from the lower end surface of the fixed core 26 combined with the needle valve 33 and the movable core 37 to the lower surface of the stopper plate 27, and between the opposing surfaces of the cores 26 and 37 when the needle valve 33 is opened. Is adjusted to a value obtained by subtracting a length ΔL (not shown) corresponding to the residual magnetism prevention gap to be provided at L1, that is, L1 = L2−ΔL. Therefore, when the needle valve 33 with the stopper flange 36 in contact with the lower surface of the stopper plate 27 is opened, a predetermined residual magnetic prevention gap ΔL can be secured between the opposing surfaces of the cores 26 and 37.

  The adjustment gap 40 provided between the inner end surface of the bag-like connecting hole 38 and the tip end surface of the head portion 34a is a chip reservoir for containing chips generated when the head portion 34a is pressed into the connecting hole 38. It is also used.

  On the lower surface of the movable core 37, a thin cylindrical portion 37a is formed integrally with the connecting hole 38 so that the inner peripheral surface thereof continues. The lower end portion of the thin cylindrical portion 37a extends over the entire circumference of the head portion 34a. Fillet welding W10 is performed by a laser. At that time, the laser irradiation point is offset from the boundary between the head portion 34a and the thin cylindrical portion 37a to the thin cylindrical portion 37a having a relatively low hardness, and both the heat input to the thin cylindrical portion 37a is increased while both 34a, 37a is laser welded to avoid cracks due to overheating of the needle valve 33 having a relatively high hardness. The heat input to the thin cylindrical portion 37a stays in the thin cylindrical portion 37a and does not reach the movable core 37 main body. In this way, the needle valve 33 and the movable core 37 are firmly coupled to each other while avoiding the deterioration of the magnetic characteristics of the movable core 37.

  The fixed core 26 has a fuel passage hole 41 penetrating through the center, and a pipe-like retainer 42 fitted in the fuel passage hole 41 is fixed to the fixed core 26 by caulking from the outer periphery thereof. A coiled valve spring 43 that urges the movable core 37 in the valve closing direction of the needle valve 33 is provided between the movable core 37 and the movable core 37. At this time, the set load of the valve spring 43 is adjusted by adjusting the fitting depth of the retainer 42 into the fuel passage hole 41. The movable core 37 has a positioning recess 44 that opens at its upper end surface and receives the movable end of the valve spring 43, and a plurality of circumferentially aligned strips that communicate with the positioning recess 44 to the lower end surface of the movable core 37. A notch groove 47 is provided. The positioning recess 44 and the bag-like connecting hole 38 are blocked from each other by a common partition wall therebetween.

  The fixed core 26 is integrally provided with a fuel inlet cylinder 45 extending upward from the retainer 42, and a fuel filter 46 is attached to the inlet of the fuel inlet cylinder 45. The inside of the fuel inlet cylinder 45 communicates with the inside of the valve seat member 22 through the hollow portion of the retainer 42, the fuel passage hole 41, the positioning recess 44, the notch groove 47 and the through hole 48 of the stopper plate 27.

  As shown in FIG. 8, the through hole 48 of the stopper plate 27 has a small diameter hole 48a located in the center of the stopper plate 27, which is smaller than the outer diameter of the stopper flange 36, and a dharma-like shape on one side of the small diameter hole 48a. Are connected to the stopper flange 36 and the large diameter hole 48b larger than the outer diameter of the journals 35, 35, and before the stopper plate 27 is assembled into the valve housing 21, the journals 35, 35 and the stopper flange of the needle valve 33 are provided. After inserting 36 into the large diameter hole 48b, the stopper flange 36 can be made to face the lower surface of the stopper plate 27 by shifting the needle 34 toward the small diameter hole 48a.

  Thus, the dharma-shaped through-hole 48 composed of the small-diameter hole 48a and the large-diameter hole 48b is not a notch that reaches the outer periphery of the stopper plate 27. Even if generated, the chips are confined between the fixed core 26 and the stopper plate 27 and can be prevented from entering the fuel passage.

  In addition, the stopper plate 27 that has no notches and has the entire circumference closed has high rigidity, and in addition, a wide contact surface of the stopper flange 36 around the small-diameter hole 48a of the stopper plate 27 can be obtained. The valve opening stroke and the valve opening attitude of the valve 33 can always be properly controlled, which can contribute to the stabilization of the fuel injection characteristics of the fuel injection valve I.

  A coil assembly 50 that cooperates with the fixed core 26 and the movable core 37 is disposed on the outer periphery of the valve housing 21. The coil assembly 50 includes a bobbin 51 fitted to the outer periphery of the nonmagnetic collar 25 and the fixed core 26 and a coil 52 wound around the bobbin 51, and a magnetic body surrounding the coil assembly 28. The coil housing 53 is laser welded W8 to the lower yoke 24. An annular upper yoke 54 fitted to the outer periphery of the fixed core 26 is superimposed on the upper end of the coil housing 53, and laser welding W9 is performed. As described above, since the lower yoke 24 and the coil housing 53, both of which are magnetic materials, are separated from each other, the lower yoke 24, the nonmagnetic collar 25 and the fixed core 26 are obstructed by the coil housing 53 before they are welded. Then, the lower yoke 24 and the coil housing 53 are abutted and welded to each other so that they can be coupled with relatively little welding heat, and a good magnetic path is established between them. Can be formed.

  A terminal holding portion 51a for holding a pair of coil terminal plates 55, 55 connected to both ends of the coil 52 is integrally formed at the upper end of the bobbin 51. The terminal holding portion 51a includes the coil housing 53 and Arranged in continuous notches 57 and 58 on one side of the upper yoke 54. The coil terminal plates 55 and 55 are arranged in a straight line parallel to the axis of the valve housing 21.

  A cylindrical cover 59 made of synthetic resin is formed on the outer periphery of the valve housing 21 from the lower yoke 24 to an intermediate portion of the fuel inlet cylinder 45 by injection molding. At this time, the synthetic resin is filled into the coil housing 53 through the notches 57 and 58 and the notch 57 ′ on the other side of the coil housing 53 to cover the coil assembly 50.

  In FIG. 6, a hole 68 provided in the covering body 59 is an insertion hole for a caulking tool used when the retainer 42 is fixed by caulking the outer periphery of the fuel inlet cylinder 45.

  As shown in FIGS. 4, 5, 9, 10, and 16, the covering body 59 includes a large-diameter cylindrical portion 59 a that covers the outer periphery of the coil assembly 50, and an upper end surface of the large-diameter cylindrical portion 59 a. A small-diameter cylindrical portion 59b that projects from the upper end surface of the large-diameter cylindrical portion 59a and projects from the upper end surface of the large-diameter cylindrical portion 59a. 67 includes an upper upper stage 67a and a lower stage 67b surrounding the upper stage 67a. The upper stage 67a and the lower stage 67b face upward, that is, toward the fuel inlet cylinder 45, and the pair of coil terminal plates 55 and 55 are disposed so as to protrude in parallel with the axis of the valve housing 21 from the upper stage 67a. . Two conductive wires 61, 61 connected to the coupler 66 are connected to the coil terminal plates 55, 55 via a pair of connector plates 60.

  The connection structure will be described in detail. As clearly shown in FIGS. 6 and 15, the connector plate 60 has a strip shape so as to be arranged in a straight line parallel to the axis of the valve housing 21. Are formed with a pair of first connection pieces 60a, 60a having a U-shaped cross section facing the open ports, and a second connection piece 60b having a U-shaped cross section is formed at the other end. By inserting the terminals of the corresponding conductors 61 and 61 between the pair of first connection pieces 60a and 60a and caulking the pair of first connection pieces 60a and 60a so as to enclose the terminals, the conductors 61 and 61 The connector plate 60 is firmly connected via the first connection pieces 60a and 60a. Such connector plates 60 with conducting wires 61, 61 are produced in large quantities in advance.

  Next, the connector plate 60 is placed in a state parallel to the axis of the valve housing 21, and the second connection piece 60b is caulked and temporarily fixed to the corresponding coil terminal plates 55 and 55, followed by electrodeposition. By doing so, the connector plate 60 and the coil terminal plates 55 and 55 can be connected with high accuracy and efficiency even in the vicinity of the covering body 59, which can contribute to the improvement of productivity.

  Thus, the covering 59 has a cylindrical shape concentric with the valve housing 21, and the coil terminal plates 55, 55 embedded in the covering 59 are arranged linearly in parallel with the axis of the valve housing 21. When molding 59, the molding die can be released along the axial direction of the valve housing 21 without being obstructed by the coil terminal plates 55, 55, and the structure of the molding die can be simplified. it can.

  Similarly to the coil terminal plates 55, 55, the connector plate 60 is also arranged in parallel with the axis of the valve housing 21, so that these do not become large protrusions outward from the covering body 59. Can be sufficiently reduced in diameter.

  As clearly shown in FIGS. 6 and 10, the connection portions of the connector plate 60, the coil terminal plates 55 and 55, and the conducting wires 61 and 61 are covered with a synthetic resin connection portion cover 62. The connection portion cover 62 is connected to the outer wall 62a having an arcuate cross section covering the outer surface of the connection portion, and both ends of the outer wall 62a. 59 includes a pair of engaging walls 62b and 62b intervening between the small-diameter cylindrical portion 59b and a partition wall 62c protruding from the inner surface of the outer wall 62a and interposing between the two connector plates 60. The outer side wall 62 a is formed so that the outer surface thereof is continuous with the outer peripheral surface of the large-diameter cylindrical portion 59 a of the covering body 59. On the other hand, on one side of the small-diameter cylindrical portion 59b of the covering body 59, a guide convex portion 69 is formed to engage the engaging walls 62b, 62b so as to be slidable in the axial direction, and guides for the engaging walls 62b, 62b are formed. The axial sliding limit on the convex portion 69 is regulated by the lower end of the connection portion cover 62 coming into contact with the lower step 67 b of the step portion 67.

  Thus, the engagement walls 62b, 62b of the connection portion cover 62 are engaged with each other by sliding the guide projection 69 in the axial direction, and the lower end of the connection portion cover 62 is brought into contact with the lower step 67b of the step portion 67. By doing so, a cavity 86 for accommodating the connector plate 60 can be defined between the connection portion cover 62 and the small diameter cylindrical portion 59b. Therefore, the insulating resin 63 is potted with the insulating resin, whereby the connector plate 60, the coil terminal plates 55 and 55, and the connecting portions of the conducting wires 61 and 61 are embedded in the insulating resin 63. At that time, the engagement between the engagement walls 62b and 62b and the guide protrusion 69 and the contact between the lower end of the connection portion cover 62 and the lower step 67b of the step portion 67 can prevent the potting resin from leaking out.

  As clearly shown in FIG. 9, the identification number or symbol 64 of the fuel injection valve I is displayed on the outer surface of the connecting portion cover 62, and the identification number or symbol 64 corresponds to the injection valve protection cylinder 3. It can recognize from the lower peep hole 65 provided in one side wall.

  A mounting cap 70 that couples the injection valve protection cylinder 3 is attached to the front end portion, that is, the lower end portion of the fuel injection valve I. The mounting cap 70 includes a small-diameter cylindrical portion 70 a that fits to the outer peripheral surface of the tip end portion of the valve seat member 22, and a large-diameter cylindrical portion that fits to the outer peripheral surface of the connecting cylindrical portion 24 a and contacts the lower end surface of the lower yoke 24. 70b. An annular groove 71 is formed on the outer periphery of the distal end portion of the valve seat member 22, and a heat-resistant seal member 72 that is in close contact with the inner peripheral surface of the small-diameter cylindrical portion 70a is attached thereto.

  A press-fit portion 73 having a slightly larger diameter than the lower portion is formed at the upper portion of the outer peripheral surface of the connecting cylinder portion 24a. The press-fit portion 73 is press-fitted into the upper inner peripheral surface of the large-diameter tube portion 70b, A heat insulating gap 94 is provided between the opposed peripheral surfaces of the seat member 22 and the small-diameter cylindrical portion 70a. An annular stress relief groove 74 is formed in the upper end surface of the large-diameter cylindrical portion 70b in the vicinity of the inner peripheral surface thereof, and the large-diameter deformation of the inner peripheral surface of the large-diameter cylindrical portion 70b due to an excessive load during the press-fitting. Is allowed by the stress relief groove 74. On the upper surface of the large-diameter portion 70 b, the outer peripheral surface is wider than the inner peripheral surface of the stress relief groove 74, and the wide surface abuts against the lower end surface of the lower yoke 24. The press-fit limit between 73 and the large-diameter cylindrical portion 70b is regulated.

  The lower yoke 24 includes a small flange 75 having a slightly larger diameter than the cover 59 covering the coil housing 53 on the outer periphery of the lower end portion, and the large diameter cylindrical portion 70b has a diameter larger than that of the small flange 75 on the outer periphery of the upper end portion. The large flange 76 is integrally provided, and the small flange 75 is joined to the upper surface of the large flange 76 over the entire circumference by laser welding W2. The welding heat at that time is absorbed by the small flange 75 and has a very small effect on the entire lower yoke 24, so that the magnetic properties of the lower yoke 24 can be prevented from deteriorating.

  The injection valve protection cylinder 3 is fitted to the outer peripheral surface of the small flange 75 while accommodating the cover 59, and the lower end surface is brought into contact with the upper surface of the large flange 76. And the outer periphery of the contact portion of the large flange 76 is joined by laser welding W3 over the entire circumference. In this way, the fuel injection valve I is held by the injection valve protection cylinder 3 via the mounting cap 70.

  As shown in FIGS. 5 and 11, a gasket 77 made of a thin spring steel plate is attached to the outer periphery of the small diameter cylindrical portion 70 a of the attachment cap 70. The gasket 77 includes an annular elastic seal portion 77a that elastically contacts the end surface of the small-diameter cylindrical portion 70a, and a plurality of leg pieces 77b that bend and extend in the axial direction from the outer periphery of the seal portion 77a. The gasket 77 is attached to the small diameter cylindrical portion 70a by elastically engaging the claw portion 77c formed at the tip of each leg piece 77b with the outer peripheral groove 78 of the small diameter cylindrical portion 70a.

  In FIG. 5 again, the injection valve protection cylinder 3 is inserted into the guide portion 17 with the mounting cap 70 at the top. The small diameter cylindrical portion 70 a of the mounting cap 70 is fitted in the guide cap 18 of the guide portion 17 together with the gasket 77, and the injection valve protection cylinder 3 is fitted in the guide cylinder 20 of the guide portion 17. At that time, the seal portion 77a of the gasket 77 is sandwiched between the end surface of the small diameter cylindrical portion 70a of the mounting cap 70 and the inward flange 18b of the guide cap 18 to achieve airtightness therebetween.

  A metal gasket 80 is also interposed between the lower surface of the large-diameter portion 70b of the mounting cap 70 and the bottom surface of the guide cap 18 in the dish-shaped flange 18a. A cylindrical heat insulating space 79 is defined between the 70 and the guide cap 18.

  As shown in FIG. 6, a seal member 83 and a backup ring 84 that supports the lower surface of the annular seal housing 82 on the outer periphery of the upper end of the fuel inlet cylinder 45 are mounted and are in close contact with the seal member 83. Thus, the lower end portion of the fuel introduction pipe 2 is fitted to the outer periphery of the upper end portion of the fuel inlet tube 45. As shown in FIG. 12, the backup ring 84 is provided with an abutment 84a inclined with respect to the axis thereof, and a tapered inner peripheral surface 84b having a large diameter downward, and the inner peripheral surface thereof. A tapered guide surface 82a facing 84b is provided in the lower portion of the seal housing 82.

  Thus, when the backup ring 84 is pressed downward together with the seal member 83 by the high-pressure fuel from the fuel introduction pipe 2, the diameter of the backup ring 84 is expanded by the interaction between the tapered guide surface 82a and the inner peripheral surface 84b. The seal member 83 is supported while being in close contact with the inner peripheral surface of the tube 2, and an appropriate sealing function of the seal member 83 is ensured.

  The injection valve protection cylinder 3 is provided with a pair of upper peeping holes 85 located on both sides of the seal housing 82, and when the fuel introduction pipe 2 is fitted into the fuel inlet cylinder 45, The proper mounting state of the seal member 83 and the backup ring 84 can be confirmed from these upper peep holes 85.

  As shown in FIG. 7, the fuel introduction pipe 2 extends to above the injection valve protection cylinder 3, a closing ring 87 is press-fitted into the outer peripheral surface of the intermediate part, and is inserted into the outer peripheral shoulder 2 a of the fuel introduction pipe 2. All-around laser welding W4 is fixed. The closing ring 87 presses the outer periphery of the lower end portion into the inner peripheral surface of the injection valve protection cylinder 3 to hold the fuel introduction pipe 2 and the injection valve protection cylinder 3 concentrically. At the same time, the closing ring 87 is integrated by applying a flange 87a projecting to the outer periphery of the closing ring 87 to the upper end surface of the injection valve protection cylinder 3 and laser welding W5.

  Further, a sealing ring 88 made of an elastic material such as rubber for sealing between the closing ring 87 and the guide cylinder 20 is fitted to the outer periphery of the closing ring 87 above the flange 87a. The seal ring 88 is fixed in the axial position on the closing ring 87 by fitting the annular positioning protrusion 89 on the inner periphery thereof into the annular positioning groove 90 on the outer periphery of the closing ring 87.

  As clearly shown in FIG. 13, an annular inner peripheral seal lip 88 a is integrally formed on the inner peripheral surface of the positioning ring 89 of the seal ring 88, and an annular outer peripheral seal lip 88 b is integrally formed on the outer peripheral surface of the seal ring 88. The inner peripheral seal lip 88a is in intimate contact with the bottom surface of the positioning groove 90, and the outer peripheral seal lip 88b is in intimate contact with the inner peripheral surface of the guide cylinder 20, so that the gap between the closing ring 87 and the guide cylinder 20 is sealed. Is done.

  As shown in FIGS. 3, 7, and 14, the two conducting wires 61, 61 are provided on one side of the upper end portion of the injection valve protection cylinder 3 and one side of the flange 87 a of the closing ring 87. Are passed through the notches 91 and 92, and are further drawn out through the through holes 93 and 93 provided on one side wall of the seal ring 88. A plurality of seal lips 88 c, 88 c, which are in close contact with the outer peripheral surface of the insulation coating of the conducting wires 61, 61 are integrally formed on the inner peripheral surfaces of the through holes 93, 93 of the seal ring 88.

  A conductor protecting member 96 for preventing the conductors 61 and 61 from protruding from the notches 91 and 92 is attached to the notches 91 and 92. The conductive wire protection member 96 is made of synthetic resin, and is formed by connecting the base ends of a pair of holding pieces 96a and 96a having holding grooves 96b and 96b with open surfaces facing each other at the distal ends. When the gap between the pieces 96a and 96a is opened and the two conducting wires 61 and 61 are engaged with the holding grooves 96b and 96b, and then the holding pieces 96a and 96a are fitted into the notches 91 and 92, both holding The pieces 96a and 96a are held in proximity to each other so as to prevent the conductors 61 and 61 from being detached from the holding grooves 96b and 96b.

  The seal ring 88 is connected with a breather tube 97 that allows breathing inside the guide cylinder 20, and the open end of the breather tube 97 is disposed in a place where rainwater, washing water, etc. are difficult to be applied.

  1 to 4 again, the connection structure of the branch pipe 6 and the fuel introduction pipe 2 will be described. The branch pipe 6 and the fuel introduction pipe 2 are respectively formed with an elliptical upper connection flange 100 and a lower connection flange 101 that face each other. The upper connecting flange 100 is provided with a bent path 102 opened on the side surface and the lower surface thereof, and the downstream end of the branch pipe 6 is fitted and brazed to the side opening of the bent path 102. On the other hand, the lower connecting flange 101 is provided with a passage 105 penetrating the center thereof, and on the upper surface of the lower connecting flange 101, a circular communication recess for communicating the passage 105 with the lower opening of the bent path 102 is provided. A circular connecting recess 104 is provided on the lower surface thereof, and the upper end of the fuel introduction pipe 2 is press-fitted into the connecting recess 104. A chamfer 2b is provided on the outer periphery of the upper end portion of the fuel introduction pipe 2 to prevent generation of chips during the press-fitting. The fuel introduction pipe 2 is integrated by laser welding W5 around the outer peripheral surface of the fuel introduction pipe 2 to the lower surface of the lower connecting flange 101.

  A backup ring 107 fitted to the inner peripheral surface of the communication recess 103 and a seal member 108 in contact with the inner peripheral surface of the backup ring 107 are mounted. The upper and lower connection flanges 100 and 101 are overlapped with each other and fastened by a pair of connection bolts 109 and 109. As a result, the branch pipe 6 and the fuel introduction pipe 2 are communicated with each other via the bent path 102, the communication recess 103, and the passage 105. In the communication recess 103, the seal member 108 is in close contact with both the connecting flanges 100 and 101. , Seal their joints.

  On the outer peripheral surface of the fuel introduction pipe 2 exposed above the closing ring 87, a pair of diametrically opposed flat portions 110, 110 are formed, and the fuel introduction tube 2 is formed using these flat portions 110, 110 as an assembly reference. And the fitting and fixing position between the closed ring 87 and the fitting and fixing position between the fuel introduction pipe 2 and the lower connecting flange 101 are determined.

  Next, the operation of the first embodiment will be described.

  In each fuel injection valve I, when the coil 52 is demagnetized, the needle valve 33 is pressed downward by the urging force of the valve spring 43 and is seated on the valve seat 28. Accordingly, the high-pressure fuel supplied from the fuel pump (not shown) to the fuel distribution pipe D is sent from each branch pipe 6 to the fuel inlet cylinder 45 via the fuel introduction pipe 2, and further inside the pipe-like retainer 42, the fixed core. 26, the fuel passage hole 41, the cutout groove 47 of the movable core 37 and the inside of the valve seat member 22 are put on standby.

  When the coil 52 is energized by energization, the magnetic flux generated by the coil 52 sequentially travels to the coil housing 53, the upper yoke 54, the fixed core 5, the movable core 12, the lower yoke 24, and the coil housing 53. 37 is attracted to the fixed core 26 against the set load of the valve spring 43 and the needle valve 33 is separated from the valve seat 28, so that the high-pressure fuel in the valve seat member 22 flows from the fuel injection hole 23 to the internal combustion engine E. It is directly injected into the corresponding combustion chamber 15.

  At this time, the valve opening stroke of the needle valve 33 is constantly regulated by the stopper flange 36 coming into contact with the lower surface of the stopper plate 27, and between the movable core 37 and the fixed core 26, the contact between them is constant. The residual magnetic prevention gap ΔL is maintained. Therefore, when the coil 52 is subsequently demagnetized, the residual magnetism between the cores 26 and 37 can be eliminated immediately, and the valve closing response of the needle valve 33 by the valve spring 43 can be enhanced. A notch groove 47 provided in the movable core 37 for communicating the positioning recess 44 to the valve seat member 22 side is also useful for eliminating residual magnetism between the cores 26 and 37. It can contribute to further improvement of the property.

  By the way, in order to secure the residual magnetic prevention gap ΔL, as described above, the distance L1 from the upper surface of the stopper flange 36 to the upper surface of the movable core 37 is L1 = L2−ΔL. Since the head 34a is adjusted by adjusting the press-fit depth of the movable core 37 into the connecting hole 38 of the head 34a, the residual magnetic prevention gap ΔL can be easily and accurately set without relying on cutting. Obtainable.

  Moreover, the connecting hole 38 of the movable core 37 is formed in a bag shape and is cut off from the positioning recess 44 for receiving the movable end of the valve spring 43 on the upper end surface of the movable core 37, and the adjustment gap 40 is formed of chips. Since it also serves as a reservoir, the chips generated when the head 34a of the movable core 37 is press-fitted into the connecting hole 38 can be contained in the chip reservoir 40 to prevent the chips from entering the fuel passage. Therefore, after the press-fitting, it is not necessary to perform cleaning for removing chips, and the need for cutting to adjust the residual magnetism prevention gap ΔL is eliminated, thereby improving the production efficiency. it can.

  Gaskets 77, 80 arranged vertically with a heat insulating space 79 interposed between a guide cap 18 screwed into the cylinder head 1 of the internal combustion engine E and a mounting cap 70 that holds the valve housing 21 of the fuel injection valve I. Therefore, the gaskets 77 and 80 prevent leakage of the high-pressure gas in the fuel chamber 15 to the guide portion 17, and the heat insulation space 79 prevents high heat from being transferred from the cylinder head 1 to the mounting cap 70. The fuel injection valve I, in particular, the valve seat member 22 and the needle valve 33 can be protected from heat damage.

  Even when rain water, washing water or the like falls on the open side above the guide cylinder 20, the seal ring 88 is fitted on the outer circumference of the closing ring 87 fitted to the outer circumference of the fuel introduction pipe 2 and liquid-tightly laser welded W4. Since the seal ring 88 is liquid-tightly fitted to the inner peripheral surface of the upper end portion of the guide cylinder 20, the seal ring 88 prevents water and dust from entering the guide cylinder 20. Can be prevented.

  In addition, a plurality of seal lips 88c that are in close contact with the outer peripheral surface of the insulation coating of the conductors 61, 61 are formed on the inner peripheral surface of the through holes 93, 93 of the seal ring 88 through the conductors 61, 61 of the fuel injection valve I. 88c... Is formed, and these seal lips 88c, 88c... Can prevent water and dust from entering through the through holes 93, 93 into the guide tube 20. Moreover, since the conducting wires 61 and 61 are elastically held by the seal ring 88 that seals the inside of the guide cylinder 20, vibration of the conducting wires 61 and 61 can be suppressed easily and effectively, and the conducting wires 61 and 61 Damage can be prevented.

  Moreover, since the inside of the guide cylinder 20 is open to the atmosphere via the breather tube 97, it is possible to breathe in accordance with the surrounding temperature change, and prevention of dew condensation inside the guide cylinder 20 is achieved.

  In assembling such an in-cylinder fuel injection device, first, the valve seat member 22 of the fuel injection valve I is inserted into the small-diameter cylindrical portion 70a of the mounting cap 70, and the press-fit portion 73 of the connecting cylindrical portion 24a of the lower yoke 24 is inserted. Is pressed into the inner peripheral surface of the large-diameter cylindrical portion 70b of the mounting cap 70, and the upper surface of the large-diameter cylindrical portion 70b on the outer peripheral side from the stress relief groove 74 is brought into contact with the lower surface of the lower yoke 24, To regulate. Since the flange 22a at the upper end of the valve seat member 22 is press-fitted into the inner peripheral surface of the connecting cylinder part 24a of the lower yoke 24, the valve seat member 22 and the mounting cap 70 are eventually press-fitted together via the connecting cylinder part 24a. As a result, the concentric accuracy between the two can be improved. As a result, a uniform heat insulating gap 94 can be secured between the opposed peripheral surfaces of the valve seat member 22 and the mounting cap 70, and the valve seat member 22. And the needle valve 33 in the inside can be protected from the high heat of the cylinder head 1, and the durability of them can be improved.

  Further, when an excessive press-fitting load is applied to the press-fitted portion when the connecting tube portion 24a is press-fitted into the large-diameter cylindrical portion 70b, the inner peripheral surface of the large-diameter cylindrical portion 70b is appropriately expanded in diameter toward the stress relief groove 74. As a result, the distortion of the connecting cylinder portion 24a due to excessive stress, and hence the distortion of the stopper plate 27 and the valve seat member 22, can be prevented, and the characteristics of the fuel injection valve I can be stabilized. Further, since the diameter expansion deformation of the inner peripheral surface of the large diameter cylindrical portion 70b does not reach the outer peripheral side of the stress relief groove 74, the limit of the press fit depth of the press fitting portion 73 and the large diameter cylindrical portion 70b is accurately regulated. , The mutual dimensional accuracy can be improved.

  After that, the small flange 75 of the lower yoke 24 is spread over the entire circumference of the large flange 76 of the mounting cap 70 and integrated with the fillet weld W2 by laser. According to this fillet weld W2, it is possible to weld the large flange 76 and the small flange 75 with relatively little heat input, and the welding heat stays on the small flange 75 and reaches the magnetic path of the lower yoke 24. It doesn't reach.

  In this way, the press-fitted portion of the lower yoke 24 with the mounting cap 70 and the welded portion W2 become the outer portion of the magnetic path of the lower yoke 24, and thus avoid changes in the magnetic properties of the lower yoke 24 due to the press-fit load and welding heat. This can contribute to stabilization of the fuel injection characteristics of the fuel injection valve I.

  Next, the injection valve protection cylinder 3 is fitted to the outer peripheral surface of the small flange 75, the lower end of the injection valve protection cylinder 3 is abutted against the upper surface of the large flange 76 of the mounting cap 70, and the abutment portions thereof. Laser welding W3 is performed over the entire circumference. In this way, the lower yoke 24, the mounting cap 70, and the injection valve protection cylinder 3 are integrated by laser welding W2 and W3, so there is no need to have a protruding portion around them, and the relatively small diameter is obtained. The guide tube 20 and the guide hole 19 can be fitted.

  At this stage, it is visually confirmed whether or not the seal member 83 and the backup ring 84 are properly attached to the seal housing 82 at the upper end portion of the fuel inlet tube 45 from the upper peep hole 85. Further, from the lower viewing hole 65, the identification number or symbol 64 of the fuel injection valve I displayed on the outer surface of the connection portion cover 62 is visually confirmed to prevent erroneous assembly.

  On the other hand, the fuel introduction pipe 2 is fitted with a closing ring 87 and a lower connecting flange 101 at predetermined positions by press-fitting and laser welding W4, W5 with respect to the flat portions 110, 110 on the outer periphery, and further, the outer periphery of the closing ring 87 The seal ring 88 is mounted at the fixed position.

  Thereafter, the conductors 61 and 61 of the fuel injection valve I are drawn out through the through holes 93 and 93 of the seal ring 88, and the upper part of the conductor protection member 96 that holds the conductors 61 and 61 is closed below the seal ring 88. Engage with the notch 92 in the ring 87.

  Next, the fuel introduction pipe 2 is inserted into the injection valve protection cylinder 3, and the lower end portion of the fuel introduction pipe 2 is fitted to the outer periphery of the upper end portion of the fuel inlet cylinder 45 so that the seal member 83 is in close contact with the inner peripheral surface thereof. At the same time, the closing ring 87 is fitted into the upper end portion of the injection valve protection cylinder 3, and the lower part of the conductor protection member 96 is engaged with the notch 91 of the injection valve protection cylinder 3. That is, after determining the relative positions around the axis of the closing ring 87 and the injection valve protection cylinder 3 through the conductor protection member 96, the conductors 61 and 61 are loosened in the injection valve protection cylinder 3. 61, 61 is pulled upward, and the injection valve protection cylinder 3 and the closing ring 87 are laser-welded W5. As described above, since the closing ring 87 and the injection valve protection cylinder 3 are integrated by laser welding W5, it is not necessary to have an overhanging portion around them, and it is possible to fit the guide cylinder 20 with a relatively small diameter. Become.

  Next, after attaching the backup ring 107 and the seal member 108 to the communication recess 103 of the lower connection flange 101 at the upper end of the fuel introduction pipe 2, the upper connection flange 100 of the branch pipe 6 of the fuel distribution pipe D is superimposed on the lower connection flange 101. Then, both connecting flanges 100 and 101 are fastened with connecting bolts 109 and 109.

  Thus, in the fuel distribution pipe D, a plurality of injection valve protection cylinders 3, 3 ... holding the fuel injection valves I, I ... are suspended through the plurality of branch pipes 6, 6 ... A plurality of injection valve protection cylinders 3, 3... Are inserted into a plurality of guide portions 17, 17... Including a guide cap 18 and a guide cylinder 20 provided corresponding to each cylinder on the internal combustion engine E side. Gaskets 77 and 80 are sandwiched between 18 and the mounting cap 70, and the outer peripheral seal lip 88 b of each seal ring 88 is brought into close contact with the inner peripheral surface of the guide cylinder 20. Finally, the plurality of brackets 7, 7... Of the distribution pipe body 5 are fixed to the plurality of mounting portions 8, 8.

  In this way, an assembly of the fuel injection valve I, the injection valve protection cylinder 3 and the fuel introduction pipe 2 is pre-configured outside the internal combustion engine E, and the assembly is connected to each of the plurality of branch pipes 6 of the fuel distribution pipe D. By suspending, a plurality of the above assemblies can be attached to the cylinder head 1 at the same time, and the assemblability can be greatly improved. Moreover, since the fuel passage constituent members such as the fuel introduction pipe 2 and the branch pipe 6 of the fuel distribution pipe D are used for the suspension of the assemblies, the suspension structure is simple.

  At this time, each branch pipe 6 is applied with stress for clamping the gaskets 77 and 80 between the guide caps 18 and the mounting caps 70, thereby suppressing vibration of the injection valve protection cylinder 3 and fuel injection. The concentricity of the valve I and the guide cylinder 20 can be ensured, and the fuel injection direction of the fuel injection valve I can be made constant. Therefore, it is not necessary to directly fix the injection valve protection cylinder 3 to the guide cylinder 20, and the assembling property can be further improved.

  In addition, the fuel injection valve I is accommodated and held in the mounting cap 70 and the valve seat member 22 is stored in the injection valve protection cylinder 3 to which the mounting cap 70 is coupled, that is, only the lower end portion is supported by the mounting cap 70. Therefore, even when an attachment load is applied to the attachment cap 70 and the injection valve protection cylinder 3 when the assembly is attached to the cylinder head 1, it is understood that the load acts on the fuel injection valve I. This can be prevented by the valve protection cylinder 3, and therefore, the fuel injection valve I does not generate unnecessary stress, so that stable fuel injection characteristics can always be exhibited.

  On the other hand, when the brackets 7, 7... Are removed from the mounting portions 8, 8... And the fuel distribution pipe D is pulled up, a plurality of injection valve protection cylinders 3, 3,. Can be drawn all at once from the guide portions 17, 17.

  The coil terminal plates 55 and 55 and the connector plate 60 are arranged in parallel to the axis of the valve housing 21 in the vicinity of the small diameter cylindrical portion 59b of the covering body 59, and the connector plate 60, the coil terminal plates 55 and 55, and the conducting wires 61, Since the connection portion cover 62 that covers each connection portion with the 61 is formed so as to be continuous with the large-diameter cylindrical portion 59a of the cover body 59, the connector plate 60, the connection portion cover 62, and the like are outside the cover body 59. The diameter of the electromagnetic fuel injection valve I can be greatly reduced, and as a result, the electromagnetic fuel injection valve I can be inserted into the relatively small diameter injection valve protection cylinder 3. It becomes possible.

  In addition, each connecting portion between the connector plate 60, the coil terminal plates 55 and 55, and the conducting wires 61 and 61 is embedded by an insulating resin 63 potted in the connecting portion cover 62. The waterproof, dustproof, and insulating properties of each connecting portion between the plates 55 and 55 and the conducting wires 61 and 61 can be improved, and the disconnection can be prevented, and the connecting portion cover 62 can be adhered to the covering body 59. Further, the insulating property between the two connector plates 60 can be further enhanced by an extremely simple structure in which the partition wall 62c interposed between the two connector plates 60 is formed in the connecting portion cover 62.

  Further, since the coupler 66 is connected to the outer ends of the conducting wires 61, 61 connected to the connector plate 60, the coupler 66 does not become a resonance box for the operating sound in the electromagnetic fuel injection valve I, and therefore the electromagnetic fuel injection. The quietness of the valve I can be maintained.

  Next, a second embodiment of the present invention shown in FIGS. 16 and 17 will be described.

  In this second embodiment, the upper end of the injection valve protection cylinder 203 that houses and holds the fuel injection valve I ends at the height position of the middle portion of the fuel inlet cylinder 45 of the fuel injection valve I, and the upper end thereof. The lower end portion of the fuel introduction pipe 202 having the same outer diameter as that of the injection valve protection cylinder 203 is indented and abutted against each other, and the injection valve protection cylinder 203 and the fuel introduction pipe 202 are integrated by laser welding all around the abutting portion. It becomes.

  The fuel introduction pipe 202 is provided with a through groove 121 that allows the conducting wires 61 and 61 to pass therethrough. Therefore, in the second embodiment, the fuel introduction pipe 202 also serves as the closing ring 87 in the previous embodiment.

  Further, a lower end portion of the connecting bolt 112 standing from the center is implanted in the upper end surface of the fuel introduction pipe 202, and an annular groove 113 surrounding the connecting bolt 112 is formed, and a first seal is formed in the annular groove 113. A member 114 is mounted.

  On the other hand, an annular joint member 115 is fixed to the tip of the branch pipe 6 of the fuel distribution pipe D. An annular groove 116 is formed on the upper end surface of the joint member 115, and the second seal member 117 is attached to the annular groove 116. The joint member 115 is fitted to the outer periphery of the connecting bolt 112 and is disposed so that the lower end surface thereof is in close contact with the first seal member 114. A bag-shaped lock nut 118 is screwed and fastened to the upper end portion of the connecting bolt 112 protruding upward from the joint member 115, and the second seal member 117 is in close contact with the lower surface of the lock nut 118. Thus, the joint member 115 and the fuel introduction pipe 202 are connected via the connection bolt 112. An annular passage 119 that communicates with the branch pipe 6 is provided on the inner peripheral surface of the annular joint member 115, and a T-shaped passage 120 that communicates the annular passage 119 with the fuel introduction pipe 202 is provided on the connecting bolt 112. ing. Therefore, the branch pipe 6 and the fuel introduction pipe 202 are connected to each other at the same time that the joint member 115 is connected to the fuel introduction pipe 202, and the fuel leakage from the upper and lower surfaces of the joint member 115 is prevented from being first and It can be blocked by the second seal members 114 and 117.

  Since other configurations are the same as those of the previous embodiment, portions corresponding to those of the previous embodiment are denoted by the same reference numerals in FIGS. 16 and 17 and description thereof is omitted.

  According to the second embodiment, the fuel introduction pipe 202 and the branch pipe 6 can be easily connected by the annular joint member 115, the connecting bolt 112 and the lock nut 118, and the overhanging portion around the joint member 115. Therefore, the diameter of the connecting portion can be reduced.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, the electromagnetic fuel injection valve I can also be used when fuel is injected into the intake passage of an internal combustion engine.

1 is a side view of an in-cylinder fuel injection device for an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 1. FIG. 4 is a sectional view taken along line 4-4 of FIG. FIG. 5 is an enlarged view of part 5 of FIG. 4. FIG. 6 is an enlarged view of 6 parts in FIG. 4. FIG. 7 is an enlarged view of part 7 of FIG. 4. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 5. FIG. 9 is a view of the fuel injection valve in FIG. FIG. 10 is a sectional view taken along line 10-10 in FIG. 9; The perspective view of the gasket in FIG. The perspective view of the backup ring in FIG. The longitudinal cross-sectional view of the seal ring in FIG. The perspective view of the conducting wire protection member of FIG. The perspective view of a connector board and its connection part. FIG. 5 is a view corresponding to FIG. 4 showing a second embodiment of the present invention. FIG. 17 is an enlarged view of a portion 17 in FIG. 16.

Explanation of symbols

21... Valve housing 23... Fuel injection hole 50... Coil assembly 51... Bobbin 52. ... Cover 60... Connector plate 60 a... First connection piece 60 b... Second connection piece 61. ··· Outer wall 62b ··· Engagement wall 62c ··· Partition 63 ··· Insulating resin 66 ··· Coupler 67 ··· Step portion 69 ··· Guide Convex

Claims (5)

A coil assembly (50) comprising a bobbin (51) and a coil (52) wound around the outer periphery of a valve housing (21) having a fuel injection hole (23) at one end and a fuel inlet tube (45) at the other end. ), And a synthetic resin coating (59) covering the valve housing (21) and the coil assembly (50) is formed on both ends of the coil (52). In an electromagnetic fuel injection valve in which a pair of connected coil terminal plates (55) are embedded in the covering (59),
Both the coil terminal plates (55) are arranged in a straight line parallel to the axis of the valve housing (21), and the outer end portions of these coil terminal plates (55) are arranged in the middle in the axial direction of the covering (59). The valve is exposed from a stepped portion (67) formed on the fuel inlet tube (45) and facing one end of the coil terminal plate (55). One end of the coil terminal plate (55) is connected to a conducting wire (61). The other end of a pair of connector plates (60) arranged parallel to the axis of the housing (21) is connected, and a coupler (66) is connected to the outer end of the conducting wire (61). Electromagnetic fuel injection valve. The electromagnetic fuel injection valve according to claim 1,
A first connecting piece (60a) for caulking and connecting the conducting wire (61) is provided at one end of the connector plate (60), and the coil terminal plate (55) is caulked and connected to the other end. An electromagnetic fuel injection valve comprising a second connection piece (60b) for electrodeposition. The electromagnetic fuel injection valve according to claim 1 or 2,
A synthetic resin adhesive cover (62) covering the connector plate (60), the coil terminal plate (55), and the conductor (61) is connected to the step (69) and the covering (59). ) And the insulating resin (63) potted in the adhesive portion cover (62) to embed the connecting portion, and to attach the adhesive portion cover (62) to the covering body (62). 59) An electromagnetic fuel injection valve, which is bonded to 59). The electromagnetic fuel injection valve according to any one of claims 1 to 3,
Engagement walls (62b) intervening between both connector plates (60) and the cover (59) are connected to the adhesive cover (62) from the outside of both connector plates (60). An electromagnetic fuel injection valve characterized in that a guide portion (69) with which (62b) is slidably engaged in the axial direction is formed on one side of the covering (59). The electromagnetic fuel injection valve according to any one of claims 1 to 4,
An electromagnetic fuel injection valve characterized in that a partition wall (62c) intervening between the two connector plates (60) is integrally formed on the adhesive cover (62).

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