Fuel injection valve

Abstract

The upper shell (70) is disposed between the fixed core (50) and the shell (20) on the side opposite to the nozzle relative to the coil (55), and can form a magnetic circuit together with the fixed core (50) and the shell (20). The upper shell (70) has a first conical surface (St1) formed on the outer peripheral wall and a first cylindrical surface (Sc1) formed on the inner peripheral wall. The shell (20) has a second conical surface (St2) radially facing the first conical surface (St1). The fixed core (50) has a second cylindrical surface (Sc2) radially facing the first cylindrical surface (Sc1).

Description

[0001] Cross-references of related applications

[0002] This application is based on Japanese Patent Application No. 2020-063118 filed on March 31, 2020 and Japanese Patent Application No. 2021-053154 filed on March 26, 2021, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a fuel injection valve. Background Art

[0004] Conventionally, there is known a fuel injection valve in which an upper housing is provided between a fixed core and a housing, and a magnetic path is formed among the fixed core, the upper housing, and the housing when electricity is supplied to the coil.

[0005] For example, in the fuel injection valve of Patent Document 1, the upper shell is disposed between the fixed core and the shell on the side opposite to the injection hole relative to the coil. Here, the outer peripheral wall of the upper shell is threadedly coupled to the inner peripheral wall of the shell, and the surface of the injection hole side of the inner edge is pressed against the stepped surface of the fixed core. Thus, an efficient magnetic circuit with a small magnetic gap and magnetic resistance is formed in the fixed core, the upper shell, and the shell.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2018-025184 Summary of the invention

[0009] However, in the fuel injection valve of Patent Document 1, it is necessary to form a threaded portion on the outer peripheral wall of the upper shell and the inner peripheral wall of the shell. In addition, it is necessary to assemble the upper shell by threaded fastening. Therefore, the processing and assembly of the upper shell are difficult, and the processing cost and assembly cost of the upper shell are likely to increase.

[0010] Here, if the upper shell is to be set between the fixed core and the shell by pressing in in order to facilitate the processing and assembly of the upper shell, when the outer circumferential wall of the fixed core and the inner circumferential wall of the shell are pressed in in both directions of the inner circumferential wall and the outer circumferential wall of the upper shell, the gap between the upper shell and the fixed core and the shell is uneven, so the assembly of the upper shell may become difficult.

[0011] In addition, when the outer circumferential wall of the fixed core or the inner circumferential wall of the housing is pressed into one direction of the inner circumferential wall of the upper housing, a gap is generated between the inner circumferential wall of the upper housing and the inner circumferential wall of the housing or the outer circumferential wall of the fixed core, and it may be difficult to form a magnetic gap and an efficient magnetic circuit with a small magnetic resistance in the fixed core, the upper housing, and the housing. In this case, it may be difficult to efficiently generate an attractive force for the current input to the coil. Therefore, the energy required to drive the fuel injection valve may increase.

[0012] An object of the present disclosure is to provide a fuel injection valve that is easy to assemble and can reduce power consumption.

[0013] The fuel injection valve disclosed in the present invention comprises a nozzle portion, a housing, a needle, a movable core, a fixed core, a coil and an upper housing. The nozzle portion has a spray hole for spraying fuel and a valve seat formed around the spray hole. The housing is formed in a cylindrical shape and is arranged to be connected to the side of the nozzle portion opposite to the spray hole.

[0014] The needle can open and close the injection hole by separating one end from the valve seat or contacting the valve seat. The movable core is provided on the needle. The fixed core is formed in a cylindrical shape and is provided on the side opposite to the injection hole relative to the movable core, and at least a part of the axial direction is located radially inside the housing.

[0015] The coil is disposed between the fixed core and the housing, and can attract the movable core and the needle to the fixed core side by energizing. The upper housing is disposed between the fixed core and the housing on the side opposite to the nozzle hole relative to the coil, and can form a magnetic circuit together with the fixed core and the housing.

[0016] In the first embodiment of the present disclosure, the upper shell has a first conical surface formed on one of the outer peripheral wall and the inner peripheral wall, and a first cylindrical surface formed on the other of the outer peripheral wall and the inner peripheral wall. One of the shell and the fixed core has a second conical surface facing the first conical surface in the radial direction. The other of the shell and the fixed core has a second cylindrical surface facing the first cylindrical surface in the radial direction.

[0017] Therefore, by appropriately setting the diameters of the first conical surface, the second conical surface, the first cylindrical surface, and the second cylindrical surface before assembling the upper shell, when assembling the upper shell, by inserting the upper shell from the side opposite to the nozzle relative to the coil between the fixed core and the shell, the first cylindrical surface can be abutted and tightly attached to the second cylindrical surface while the first conical surface and the second conical surface are axially slid and the upper shell is deformed radially inward or radially outward.

[0018] Thus, after the upper housing is assembled, the first tapered surface and the second tapered surface are in close contact with each other, and the first cylindrical surface and the second cylindrical surface are in close contact with each other.

[0019] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core, the upper shell and the shell. Therefore, an attractive force can be efficiently generated for the current input to the coil, and the energy required for driving the fuel injection valve can be reduced. As a result, the power consumption of the fuel injection valve can be reduced.

[0020] In addition, in the second mode of the present disclosure, the upper shell has an inner member and an outer member arranged radially outward of the inner member. The inner member has a first conical surface formed on the outer peripheral wall and a first cylindrical surface formed on the inner peripheral wall. The outer member has a second conical surface formed on the inner peripheral wall in a manner radially facing the first conical surface and a second cylindrical surface formed on the outer peripheral wall. The fixed core has a third cylindrical surface radially facing the first cylindrical surface. The shell has a fourth cylindrical surface radially facing the second cylindrical surface.

[0021] Therefore, by appropriately setting the diameters of the first conical surface, the second conical surface, the first cylindrical surface, the second cylindrical surface, the third cylindrical surface, and the fourth cylindrical surface before assembling the upper shell, when assembling the upper shell, for example, by inserting the inner member between the fixed core and the outer member from the side opposite to the nozzle hole relative to the coil while the outer member is inserted between the fixed core and the shell, the first conical surface and the second conical surface can be axially slid while the inner member is deformed radially inwardly so that the first cylindrical surface and the third cylindrical surface are abutted and tightly fitted, and the outer member can be deformed radially outward so that the second cylindrical surface and the fourth cylindrical surface are abutted and tightly fitted.

[0022] In addition, when assembling the upper shell, for example, by inserting the outer member between the inner member and the shell from the side opposite to the nozzle hole relative to the coil while the inner member is inserted between the fixed core and the shell, the first conical surface and the second conical surface can be axially slid while the outer member is deformed radially outward so that the second cylindrical surface and the fourth cylindrical surface abut and fit tightly together, and the inner member can be deformed radially inward so that the first cylindrical surface and the third cylindrical surface abut and fit tightly together.

[0023] Thus, after the upper housing is assembled, the first tapered surface is in close contact with the second tapered surface, the first cylindrical surface is in close contact with the third cylindrical surface, and the second cylindrical surface is in close contact with the fourth cylindrical surface.

[0024] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core, the upper shell and the shell. Therefore, an attractive force can be efficiently generated for the current input to the coil, and the energy required for driving the fuel injection valve can be reduced. As a result, the power consumption of the fuel injection valve can be reduced.

[0025] In addition, in this embodiment, by forming the upper shell from two components, the inner component and the outer component, the radial size, that is, the width, of each component can be reduced. Therefore, when assembling the upper shell, the inner component and the outer component of the upper shell can be easily deformed in the radial direction. As a result, the assembly load of the upper shell is reduced, and the assemblability can be improved. In addition, after the upper shell is assembled, the first conical surface is more closely attached to the second conical surface, the first cylindrical surface is more closely attached to the third cylindrical surface, and the second cylindrical surface is more closely attached to the fourth cylindrical surface.

[0026] In addition, in a third aspect of the present disclosure, the upper shell has a bottom, an inner extending portion formed so as to extend from an inner edge portion of the bottom in an axial direction of the bottom, and an outer extending portion formed so as to extend from an outer edge portion of the bottom in an axial direction of the bottom.

[0027] Therefore, by appropriately setting the inner diameter of the inner extension portion of the upper shell, the outer diameter of the outer extension portion, the outer diameter of the fixed core and the inner diameter of the shell before assembling the upper shell, when assembling the upper shell, by inserting the upper shell from the side opposite to the nozzle relative to the coil between the fixed core and the shell, for example, the inner circumferential wall of the inner extension portion can be axially slid with the outer circumferential wall of the fixed core, and the outer circumferential wall of the outer extension portion can be axially slid with the inner circumferential wall of the shell, while the inner extension portion can be deformed radially outward or the outer extension portion can be deformed radially inward.

[0028] Thus, after the upper housing is assembled, the inner peripheral wall of the inner extension portion is in close contact with the outer peripheral wall of the fixed core, and the outer peripheral wall of the outer extension portion is in close contact with the inner peripheral wall of the housing.

[0029] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core, the upper shell and the shell. Therefore, an attractive force can be efficiently generated for the current input to the coil, and the energy required for driving the fuel injection valve can be reduced. As a result, the power consumption of the fuel injection valve can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above objects and other objects, features and advantages of the present disclosure will become more apparent through the following detailed description with reference to the accompanying drawings.

[0031] Figure 1 It is a cross-sectional view showing the fuel injection valve according to the first embodiment.

[0032] Figure 2 It is a cross-sectional view showing an upper housing and its surroundings of the fuel injection valve according to the first embodiment.

[0033] Figure 3 It is a plan view showing an upper housing of the fuel injection valve according to the first embodiment.

[0034] Figure 4 It is a cross-sectional view for explaining the assembly process of the upper housing of the fuel injection valve based on the first embodiment.

[0035] Figure 5 It is a cross-sectional view showing a state where the upper housing of the fuel injection valve according to the first embodiment is assembled.

[0036] Figure 6 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a first comparative embodiment.

[0037] Figure 7 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a second embodiment.

[0038] Figure 8 It is a cross-sectional view for explaining the assembly process of the upper housing of the fuel injection valve based on the second embodiment.

[0039] Fig. 9 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a third embodiment.

[0040] Fig.10 It is a plan view showing an inner member of an upper housing of a fuel injection valve according to a third embodiment.

[0041] Fig.11 It is a plan view showing an outer member of an upper housing of a fuel injection valve according to a third embodiment.

[0042] Fig.12 It is a cross-sectional view showing an upper housing of a fuel injection valve according to a third embodiment.

[0043] Fig.13 It is a cross-sectional view for explaining the assembly process of the upper housing of the fuel injection valve based on the third embodiment.

[0044] Fig.14 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a second comparative embodiment.

[0045] Fig.15 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a fourth embodiment.

[0046] Fig.16 It is a cross-sectional view for explaining the assembly process of the upper housing of the fuel injection valve based on the fourth embodiment.

[0047] Fig.17 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a fifth embodiment.

[0048] Fig.18It is a cross-sectional view for explaining the assembly process of the upper housing of the fuel injection valve based on the fifth embodiment.

[0049] Fig.19 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a sixth embodiment.

[0050] Fig. 20 It is a cross-sectional view for explaining the assembly process of the upper housing of the fuel injection valve based on the sixth embodiment.

[0051] Fig.21 It is a plan view showing an upper housing of a fuel injection valve according to a seventh embodiment.

[0052] Fig. 22 It is a plan view showing an upper housing of a fuel injection valve according to an eighth embodiment.

[0053] Fig.23 It is a plan view showing an upper housing of a fuel injection valve according to a ninth embodiment.

[0054] Fig.24 It is a plan view showing an upper casing of a fuel injection valve according to a tenth embodiment.

[0055] Fig.25 Looking from the direction of arrow XXV Fig.24 When the picture.

[0056] Fig.26 It is a cross-sectional view showing an upper casing and its surroundings of a fuel injection valve according to an eleventh embodiment.

[0057] Fig. 27 It is a cross-sectional view for explaining the assembly process of the upper housing of the fuel injection valve according to the eleventh embodiment.

[0058] Fig.28 It is a cross-sectional view showing a state of an assembling process of an upper housing of a fuel injection valve according to a thirteenth embodiment.

[0059] Fig.29 It is a cross-sectional view showing a state of an assembling process of an upper housing of a fuel injection valve according to a fourteenth embodiment.

[0060] Fig.30 It is a cross-sectional view showing a state of an assembling process of an upper housing of a fuel injection valve according to a fifteenth embodiment.

[0061] Fig.31 It is a cross-sectional view showing a state of an assembling process of an upper housing of a fuel injection valve according to the nineteenth embodiment.

[0062] Fig.32It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a first reference embodiment.

[0063] Fig.33 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a second reference embodiment.

[0064] Fig.34 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a third reference embodiment.

[0065] Fig.35 It is a cross-sectional view showing an upper housing and its surroundings of a fuel injection valve according to a fourth reference embodiment.

[0066] Fig.36 It is a cross-sectional view showing a fuel injection valve according to a twentieth embodiment.

[0067] Fig.37 It is a front view showing a fuel injection valve according to the twentieth embodiment.

[0068] Fig.38 It is a perspective view showing a fuel injection valve according to a twentieth embodiment.

[0069] Fig.39 It is a perspective view showing a fuel injection valve according to a twentieth embodiment.

[0070] Fig.40 It is a perspective view showing a part of the fuel injection valve according to the twentieth embodiment.

[0071] Fig.41 It is a perspective view showing a state during the manufacturing of the fuel injection valve according to the twentieth embodiment.

[0072] Fig.42 It is a partial perspective view showing a state during the manufacturing of the fuel injection valve according to the twentieth embodiment.

[0073] Fig.43 It is a partial perspective view showing a state during the manufacturing of the fuel injection valve according to the twentieth embodiment.

[0074] Fig.44 It is a top view showing a ring stopper of a fuel injection valve according to a twentieth embodiment.

[0075] Fig.45 yes Fig.44 Cross-sectional view of the XLV-XLV line.

[0076] Fig.46 It is a plan view showing a ring stopper of a fuel injection valve according to a third comparative embodiment.

[0077] Fig.47yes Fig.46 Cross-sectional view along line XLVII-XLVII.

[0078] Fig.48 This is a cross-sectional view showing a part of a fuel injection valve according to a twentieth embodiment.

[0079] Fig.49 It is a partial perspective view showing a state during the manufacturing of the fuel injection valve according to the twentieth embodiment.

[0080] Fig.50 It is a plan view showing a flange inlet of a fuel injection valve according to a twentieth embodiment.

[0081] Fig.51 This is a partial cross-sectional view showing a fuel injection valve according to the twentieth embodiment in a state during manufacture.

[0082] Fig.52 yes Fig.51 Cross-sectional view of the LII-LII line.

[0083] Fig.53 This is a cross-sectional view showing a part of a fuel injection valve according to a twentieth embodiment.

[0084] Fig.54 This is a cross-sectional view showing a part of a fuel injection valve according to a twentieth embodiment.

[0085] Fig.55 This is a cross-sectional view showing a part of a fuel injection valve according to a twentieth embodiment. DETAILED DESCRIPTION

[0086] Hereinafter, a fuel injection valve according to a plurality of embodiments will be described with reference to the drawings. In addition, substantially the same components in the plurality of embodiments are denoted by the same reference numerals, and description thereof will be omitted.

[0087] (First embodiment)

[0088] Figure 1 2 shows a fuel injection valve according to a first embodiment. The fuel injection valve 1 is applied to, for example, a gasoline engine (hereinafter simply referred to as an "engine") as an internal combustion engine mounted on a vehicle (not shown). The fuel injection valve 1 injects gasoline as fuel and supplies it to the engine.

[0089] The fuel injection valve 1 includes a nozzle portion 10 , a housing 20 , a needle 30 , a movable core 40 , a fixed core 50 , a coil 55 , an upper housing 70 , a spring 63 , a spring 65 , and the like.

[0090] The nozzle portion 10 includes a nozzle end portion 11 and a nozzle tube portion 12 .

[0091] The nozzle end 11 is formed of, for example, a metal in a bottomed cylindrical shape. The nozzle end 11 has a spray hole 13 and a valve seat 14. A plurality of spray holes 13 are formed so as to penetrate the bottom of the nozzle end 11 from the inside to the outside. The valve seat 14 is formed in a ring shape around the spray hole 13 on the inside of the bottom of the nozzle end 11.

[0092] The nozzle barrel 12 is formed into a cylindrical shape by a magnetic material such as metal, for example. The nozzle barrel 12 is provided so as to be integrated with the nozzle end 11 in such a way that the inner peripheral wall at one axial end is fitted into the outer peripheral wall of the nozzle end 11. Here, the nozzle barrel 12 and the nozzle end 11 are joined, for example, by welding.

[0093] The housing 20 is formed in a cylindrical shape by a magnetic material such as metal, for example. The housing 20 is provided so as to be connected to the side of the nozzle portion 10 opposite to the injection hole 13 .

[0094] More specifically, the housing 20 includes an outer cylindrical portion 21, an outer annular portion 22, an inner cylindrical portion 23, and an inner annular portion 24 (see Figure 2 ).

[0095] The outer cylinder 21 is formed in a cylindrical shape. The outer annular portion 22 is formed in an annular shape so as to extend radially inward from one axial end of the outer cylinder 21. The inner cylinder 23 is formed in a cylindrical shape so as to extend from the inner edge of the outer annular portion 22 to the side opposite to the outer cylinder 21. The inner annular portion 24 is formed in an annular shape so as to extend radially inward from the end of the inner cylinder 23 on the side opposite to the outer annular portion 22.

[0096] An annular housing recess 201 recessed radially outward is formed on the inner peripheral wall of the end portion of the outer cylinder portion 21 opposite to the outer annular portion 22. Two housing recesses 201 are formed in the axial direction of the outer cylinder portion 21.

[0097] An annular nozzle step surface 121 is formed on the outer peripheral wall of the nozzle barrel portion 12 of the nozzle portion 10 on the side opposite to the nozzle end portion 11. The housing 20 is provided to be connected to the side of the nozzle barrel portion 12 opposite to the nozzle hole 13 in such a manner that the end surface of the inner annular portion 24 abuts against the nozzle step surface 121 and the inner peripheral wall of the inner barrel portion 23 abuts against the outer peripheral wall of the nozzle barrel portion 12.

[0098] The needle 30 is formed of, for example, non-magnetic metal and includes a needle body 31 and a flange portion 34 .

[0099] The needle body 31 is formed in a rod shape. The flange portion 34 is formed in an annular shape so as to extend radially outward from the end of the needle body 31. The needle 30 is provided inside the nozzle portion 10 so as to be reciprocable in the axial direction inside the nozzle cylinder portion 12 and the nozzle end portion 11.

[0100] The needle 30 is formed with an axial flow path 301 and a radial flow path 302. The axial flow path 301 is formed to extend in the axial direction from the end surface of the needle body 31 on the side opposite to the nozzle end 11. The radial flow path 302 is formed to extend in the radial direction of the needle body 31 to connect the axial flow path 301 to the outer wall of the needle body 31. Thus, the fuel on the side opposite to the nozzle end 11 with respect to the needle 30 can flow between the outer peripheral wall of the needle body 31 and the inner wall of the nozzle barrel 12 via the axial flow path 301 and the radial flow path 302.

[0101] One end of the needle 30, which is the end of the needle body 31 on the nozzle end 11 side, is separated from (de-seated) or abutted against (seated) the valve seat 14 to open and close the spray hole 13. Hereinafter, the direction in which the needle 30 is separated from the valve seat 14 is appropriately referred to as the valve opening direction, and the direction in which the needle 30 abuts against the valve seat 14 is appropriately referred to as the valve closing direction.

[0102] The movable core 40 is formed into a cylindrical shape by a magnetic material such as metal, for example. The movable core 40 is provided radially outside the needle body 31 so as to be relatively movable in the axial direction relative to the needle 30 on the nozzle end 11 side relative to the flange portion 34. The movable core 40 is restricted in relative movement in the valve opening direction relative to the needle 30 by the flange portion 34.

[0103] The fixed core 50 is formed into a cylindrical shape by a magnetic material such as metal, for example. The fixed core 50 has a core recess 501 and a core recess 502. The core recess 501 is formed into an annular shape in a manner that is recessed radially inward from the outer peripheral wall at one axial end of the fixed core 50. The core recess 502 is formed into an annular shape in a manner that is recessed radially outward from the inner peripheral wall at one axial end of the fixed core 50.

[0104] The fixed core 50 is provided with the magnetic throttle portion 15 and the sleeve 51 .

[0105] The magnetic throttle portion 15 is formed of, for example, non-magnetic metal in a cylindrical shape. The magnetic throttle portion 15 is provided so as to be fitted into the core recess 501. Here, the magnetic throttle portion 15 and the fixed core 50 are joined by, for example, welding.

[0106] The sleeve 51 is formed of, for example, non-magnetic metal in a cylindrical shape and is provided so as to fit into the core recess 502 .

[0107] The fixed core 50 is provided on the side opposite to the injection hole 13 with respect to the movable core 40. Here, the end of the magnetic throttle portion 15 on the side opposite to the core recess 501 is connected to the end of the nozzle cylinder 12 on the side opposite to the nozzle end 11. The magnetic throttle portion 15 and the nozzle cylinder 12 are joined, for example, by welding.

[0108] The inner peripheral wall of the end of the sleeve 51 on the injection hole 13 side can slide with the outer peripheral wall of the flange portion 34. The end surface of the sleeve 51 on the injection hole 13 side can abut against the end surface of the movable core 40 on the side opposite to the injection hole 13.

[0109] A cylindrical adjustment tube 62 is pressed into the inner side of the fixed core 50. The spring 63 is, for example, a coil spring, and is provided between the adjustment tube 62 and the needle 30 inside the fixed core 50. One end of the spring 63 abuts against the adjustment tube 62. The other end of the spring 63 abuts against the needle 30. The spring 63 can apply force to the needle 30 and the movable core 40 toward the injection hole 13, that is, in the valve closing direction. The force of the spring 63 is adjusted by the position of the adjustment tube 62 relative to the fixed core 50.

[0110] The coil 55 is formed in a cylindrical shape, and is provided between the fixed core 50 and the case 20. The coil 55 is formed by winding a conductive wire around a cylindrical bobbin 551 made of resin.

[0111] More specifically, the coil 55 and the coil frame 551 are disposed between the fixed core 50, the magnetic throttling portion 15, the outer peripheral wall of the nozzle tube portion 12 and the inner peripheral wall of the outer tube portion 21 of the housing 20 (see Figure 2 ).

[0112] The upper housing 70 is formed of a magnetic material such as metal into a substantially C-shape (see Figure 3 The upper shell 70 is disposed between the fixed core 50 and the shell 20 on the side opposite to the nozzle hole 13 with respect to the coil 55. Here, the inner peripheral wall of the upper shell 70 is in close contact with the outer peripheral wall of the fixed core 50. In addition, the outer peripheral wall of the upper shell 70 is in close contact with the inner peripheral wall of the outer cylinder portion 21 of the shell 20.

[0113] When the coil 55 is supplied with power (energized), a magnetic force is generated. When a magnetic force is generated in the coil 55, a magnetic circuit is formed in the fixed core 50, the upper shell 70, the outer cylinder 21, the outer annular portion 22, the nozzle cylinder 12, and the movable core 40, avoiding the magnetic throttling portion 15 (refer to Figure 2 ).

[0114] As a result, a magnetic attraction force is generated between the fixed core 50 and the movable core 40, and the movable core 40 is attracted to the fixed core 50 side together with the needle 30. As a result, the needle 30 moves in the valve opening direction, and the end of the needle 30 separates from the valve seat 14, and the valve is opened. As a result, the injection hole 13 is opened, and fuel is injected from the injection hole 13. In this way, when the coil 55 is energized, it can attract the movable core 40 to the fixed core 50 side, so that the needle 30 moves to the side opposite to the valve seat 14, that is, the valve opening direction.

[0115] Furthermore, when the movable core 40 is attracted to the fixed core 50 side (valve opening direction) by the magnetic attraction force, the flange portion 34 of the needle 30 moves in the axial direction inside the sleeve 51. At this time, the outer peripheral wall of the flange portion 34 slides with the inner peripheral wall of the sleeve 51. Therefore, the axial reciprocating movement of the end portion of the needle 30 on the flange portion 34 side is guided by the sleeve 51.

[0116] When the movable core 40 is attracted to the fixed core 50 side (valve opening direction) by magnetic attraction, the end surface of the fixed core 50 side collides with the end surface of the sleeve 51 on the injection hole 13 side. Thus, the movable core 40 is restricted from moving in the valve opening direction.

[0117] When the coil 55 is de-energized while the movable core 40 is attracted to the fixed core 50, the needle 30 and the movable core 40 are urged toward the valve seat 14 by the force of the spring 63. As a result, the needle 30 moves in the valve closing direction, and the end of the needle 30 abuts against the valve seat 14 to close the valve. As a result, the injection hole 13 is blocked.

[0118] The spring 65 is, for example, a coil spring, and is disposed so that one end thereof abuts against the surface of the movable core 40 on the side of the injection hole 13 and the other end thereof abuts against the annular nozzle step surface 122 formed on the inner peripheral wall of the nozzle tube 12 (see Figure 2 ). The spring 65 can apply force to the movable core 40 toward the fixed core 50, that is, in the valve opening direction. The force of the spring 65 is smaller than the force of the spring 63. Therefore, when the coil 55 is not energized, the needle 30 is pressed against the valve seat 14 by the spring 63, and the movable core 40 is pressed against the flange portion 34.

[0119] In the present embodiment, the needle 30 is provided with a stopper 66. The stopper 66 is formed into a ring shape by, for example, a non-magnetic metal. The stopper 66 is pressed into the side of the injection hole 13 relative to the movable core 40 in a manner that the inner peripheral wall is fitted with the outer peripheral wall of the needle body 31. Here, the movable core 40 can move relative to the needle body 31 in the axial direction between the flange portion 34 and the stopper 66. The stopper 66 can limit the movement of the movable core 40 in the valve closing direction relative to the needle 30 by abutting against the surface of the movable core 40 on the injection hole 13 side.

[0120] like Figure 1 As shown, the periphery of the coil 55 and the bobbin 551 and the outer peripheral wall of the fixed core 50 are molded by a mold portion 56 made of resin.

[0121] The fuel injection valve 1 includes a connector portion 57. The connector portion 57 is formed of resin and is integrally formed with the mold portion 56 so as to protrude radially outward from the mold portion 56.

[0122] The terminal 553 is insert-molded in the connector portion 57 and the mold portion 56. The terminal 553 is formed of a conductor such as metal, one end of which is connected to the coil 55, and the other end of which is located inside the connector portion 57.

[0123] The end of the terminal 553 on the coil 55 side is molded by the coil frame extension portion 552. The coil frame extension portion 552 is formed integrally with the coil frame 551 so as to extend from the coil frame 551 to the side opposite to the nozzle hole 13 (see Figure 1 ).

[0124] A fuel flow path 100 is formed inside the fixed core 50 , the magnetic throttle portion 15 , and the nozzle portion 10 . The fuel flow path 100 is connected to the injection hole 13 .

[0125] A pipe (not shown) is connected to the end of the fixed core 50 on the opposite side from the injection hole 13 . Thus, fuel from a fuel supply source (fuel pump) flows into the fuel flow path 100 through the pipe. The fuel flow path 100 guides the fuel to the injection hole 13 .

[0126] The fuel flowing into the fuel flow path 100 from the end of the fixed core 50 opposite to the injection hole 13 flows through the fixed core 50 and the inner side of the regulating tube 62 , the axial flow path 301 , the radial flow path 302 , the needle 30 and the nozzle unit 10 , and is guided to the injection hole 13 .

[0127] The filter 2 is provided inside the end portion of the fixed core 50 on the opposite side from the injection hole 13 . The filter 2 can capture foreign matter in the fuel flowing in the fuel flow path 100 .

[0128] An electronic control unit (hereinafter referred to as "ECU") not shown is connected to terminal 553. ECU is a small computer having a CPU as a computing unit, a ROM and a RAM as a storage unit, and an I / O as an input and output unit. Based on information from various sensors installed in various parts of the vehicle, ECU controls the operation of the engine, equipment, and devices installed in the vehicle, controls the driving of the vehicle, etc.

[0129] The ECU controls the energization of the coil 55 via the terminal 553, thereby controlling the operation of the fuel injection valve 1 and the engine, and controlling the vehicle. When the coil 55 is energized by the ECU, a magnetic attraction is generated between the fixed core 50 and the movable core 40, and the movable core 40 and the needle 30 overcome the force of the spring 63 and move in the valve opening direction. Therefore, the needle 30 separates from the valve seat 14 and the valve is opened. As a result, the fuel in the fuel flow path 100 is injected into the combustion chamber of the engine outside the fuel injection valve 1 through the injection hole 13.

[0130] Next, the upper case 70 will be described in detail.

[0131] like Figure 3As shown, the upper housing 70 has a main body 71 , a cutout portion 72 , and a recessed portion 73 .

[0132] The main body 71 is formed in an annular shape by a magnetic material such as metal. The cutout portion 72 is formed by cutting off a portion of the circumferential direction of the main body 71. Thus, the main body 71 of the upper housing 70 is cut off in a portion of the circumferential direction and is formed into a C-shape when viewed from the axial direction.

[0133] The recessed portion 73 is formed so as to be recessed radially inward from the outer peripheral wall of the main body 71. Five recessed portions 73 are formed at equal intervals in the circumferential direction of the main body 71. By forming the recessed portions 73 in the main body 71, the main body 71 can be easily deformed in the radial direction.

[0134] The upper case 70 has a first tapered surface St1 and a first cylindrical surface Sc1.

[0135] Figure 3 FIG. 2 shows the upper housing 70 before being assembled between the fixed core 50 and the housing 20. The first tapered surface St1 is formed on the outer peripheral wall of the main body 71 of the upper housing 70. The first tapered surface St1 is located on a virtual tapered surface Stv1 centered on the axis of the main body 71 of the upper housing 70 (see FIG. 2 ). Figure 3 Here, the virtual tapered surface Stv1 is a tapered virtual surface that approaches the axis of the main body 71 at a predetermined ratio as it goes from one side to the other side in the axial direction of the main body 71.

[0136] The first tapered surface St1 is formed in a tapered shape so as to approach the axis of the upper housing 70 at a predetermined ratio as it moves from the side opposite to the injection hole 13 with respect to the upper housing 70 toward the injection hole 13 (see Figure 2 , Figure 3 ).

[0137] The first cylindrical surface Sc1 is formed on the inner peripheral wall of the main body 71 of the upper housing 70. The first cylindrical surface Sc1 is located on a virtual cylindrical surface Scv1 centered on the axis of the main body 71 of the upper housing 70 (see Figure 3 Here, the virtual cylindrical surface Scv1 is a virtual cylindrical surface having a constant distance from the axis of the main body 71 in the axial direction of the main body 71 .

[0138] The first cylindrical surface Sc1 is formed in a cylindrical surface shape with the axis of the upper housing 70 as the center (see Figure 2 , 3 ).

[0139] like Figure 2As shown, the housing 20 has a second tapered surface St2. The second tapered surface St2 is formed on the inner peripheral wall of the outer cylinder portion 21 of the housing 20 in a manner that faces the first tapered surface St1 formed on the outer peripheral wall of the upper housing 70 in the radial direction. The second tapered surface St2 is formed in a tapered shape in a manner that approaches the axis of the outer cylinder portion 21 at a predetermined ratio as it moves from the axial side of the outer cylinder portion 21 opposite to the injection hole 13 toward the injection hole 13 side.

[0140] like Figure 2 As shown, the fixed core 50 has a second cylindrical surface Sc2. The second cylindrical surface Sc2 is formed on the outer peripheral wall of the fixed core 50 so as to face the first cylindrical surface Sc1 formed on the inner peripheral wall of the upper housing 70 in the radial direction. The second cylindrical surface Sc2 is formed in a cylindrical surface shape with the axis of the fixed core 50 as the center.

[0141] Next, a method of assembling the upper housing 70 between the fixed core 50 and the housing 20 , that is, a method of manufacturing the fuel injection valve 1 will be described.

[0142] The method for manufacturing the fuel injection valve 1 includes the following steps.

[0143] (Case Assembly Process)

[0144] After the nozzle end 11, the nozzle barrel 12, the spring 65, the needle 30, the movable core 40, the stopper 66, the magnetic throttle 15, the fixed core 50, the sleeve 51, etc. are assembled into one body, the housing 20 is assembled to the nozzle barrel 12. Specifically, the housing 20 is inserted from the nozzle end 11 side of the nozzle portion 10 so that the inner annular portion 24 abuts against the nozzle step surface 121. Thereafter, the nozzle barrel 12 and the housing 20 are fixed by welding.

[0145] (Coil assembly process)

[0146] After the housing assembly process, the coil 55 integrated with the coil frame 551, the coil frame extension 552 and the terminal 553 is inserted between the fixed core 50 and the housing 20. Specifically, the coil 55 is inserted from the side of the fixed core 50 opposite to the nozzle 13 so that the coil 55 is located between the magnetic throttling portion 15 and the housing 20.

[0147] (Upper housing assembly process)

[0148] After the coil assembly process, the upper shell 70 is inserted between the fixed core 50 and the housing 20. Specifically, the upper shell 70 is inserted from the side of the fixed core 50 opposite to the nozzle hole 13, and the coil frame extension part 552 is located in the cutout part 72 of the upper shell 70, and the upper shell 70 is pressed into the inner side of the housing 20.

[0149] like Figure 4As shown in FIG. 1 , when the upper shell 70 is pressed into the inner side of the shell 20, first, the outer peripheral wall of the upper shell 70, i.e., the first tapered surface St1, abuts against the inner peripheral wall of the end portion of the outer cylinder portion 21 of the shell 20 on the side opposite to the injection hole 13. In this state, i.e., the state in which the first tapered surface St1 and the second tapered surface St2 are not facing each other in the radial direction, the inner diameter of the first cylindrical surface Sc1 is larger than the outer diameter of the second cylindrical surface Sc2. Therefore, in at least a portion of the circumference of the upper shell 70, a gap Sp1 is formed between the inner peripheral wall of the upper shell 70, i.e., the first cylindrical surface Sc1, and the outer peripheral wall of the fixed core 50.

[0150] In this state, that is, the state in which the first tapered surface St1 and the second tapered surface St2 do not face each other in the radial direction, the outer diameter of the end of the first tapered surface St1 on the injection hole 13 side is larger than the inner diameter of the end of the second tapered surface St2 on the injection hole 13 side.

[0151] In this state, when the upper shell 70 is further moved toward the injection hole 13, the first conical surface St1 of the upper shell 70 slides with the second conical surface St2 of the shell 20. At this time, the upper shell 70 is deformed radially inward in a manner that the inner diameter and the outer diameter are reduced. Therefore, the first cylindrical surface Sc1 of the upper shell 70 abuts against and fits tightly against the second cylindrical surface Sc2 of the fixed core 50. As a result, after the upper shell 70 is assembled, the first conical surface St1 fits tightly against the second conical surface St2, and the first cylindrical surface Sc1 fits tightly against the second cylindrical surface Sc2 (refer to Figure 4 , Figure 5 ).

[0152] (Molding process)

[0153] After the upper housing assembly process, molten resin is flowed between the fixed core 50 and the housing 20 and between the periphery of the fixed core 50 and the mold to form the molded portion 56 and the connector portion 57. At this time, the molten resin flows from the side of the upper housing 70 opposite to the injection hole 13 through the recessed portion 73 and the cutout portion 72 toward the coil 55 side. As a result, the periphery of the coil 55 is covered with resin.

[0154] Next, the present embodiment will be compared with the first comparative embodiment, and the technical advantages of the present embodiment over the first comparative embodiment will be described.

[0155] The structures of the upper housing 70 and the housing 20 of the first comparative embodiment are different from those of the first embodiment. Figure 6 As shown, in the first comparative embodiment, the outer peripheral wall of the upper shell 70 is formed into a cylindrical surface. The inner peripheral wall of the outer cylinder portion 21 of the shell 20 is formed into a cylindrical shape. Thus, in the first comparative embodiment, the upper shell 70 does not have the first tapered surface St1, and the shell 20 does not have the second tapered surface St2.

[0156] In addition, an annular step surface 205 is formed on the inner peripheral wall of the outer cylinder portion 21. The upper casing 70 abuts against the step surface 205, and movement toward the injection hole 13 side is restricted.

[0157] In the first comparative embodiment, the inner diameter of the upper housing 70 before assembly is larger than the outer diameter of the fixed core 50, and the outer diameter is larger than the inner diameter of the outer cylinder portion 21 of the housing 20. Therefore, when the upper housing 70 is assembled, it is pressed in with the outer peripheral wall in contact with the inner peripheral wall of the outer cylinder portion 21 of the housing 20. As a result, after the upper housing 70 is assembled, there is a risk that a gap serving as a magnetic gap is formed between the outer peripheral wall of the fixed core 50 and the inner peripheral wall of the upper housing 70 in at least a portion of the circumference of the upper housing 70.

[0158] Therefore, when the coil 55 is energized, there is a risk that it is difficult to form an efficient magnetic circuit with a small magnetic gap and magnetic resistance in the fixed core 50, the upper shell 70, and the shell 20. In this case, it may be difficult to efficiently generate an attractive force for the current input to the coil 55. Therefore, there is a risk that the energy required to drive the fuel injection valve increases.

[0159] On the other hand, in this embodiment, the upper shell 70 has a first conical surface St1, and the shell 20 has a second conical surface St2, so that after the upper shell 70 is assembled, the first conical surface St1 of the upper shell 70 is tightly attached to the second conical surface St2 of the shell 20, and the first cylindrical surface Sc1 of the upper shell 70 is tightly attached to the second cylindrical surface Sc2 of the fixed core 50.

[0160] Therefore, when the coil 55 is energized, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 70, and the shell 20 (see Figure 2 ). Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. Thus, the power consumption of the fuel injection valve 1 can be reduced.

[0161] exist Figure 2 In the figure, a thick single-dot chain line indicates a portion where the components are pressed into each other and in close contact (the same applies below). In the present embodiment, the outer peripheral wall (first conical surface St1) of the upper shell 70 is in close contact with the inner peripheral wall (second conical surface St2) of the shell 20, and the inner peripheral wall (first cylindrical surface Sc1) of the upper shell 70 is in close contact with the outer peripheral wall (second cylindrical surface Sc2) of the fixed core 50, and at this portion, the magnetic gap and magnetic resistance become small.

[0162] In the present embodiment, the end of the first conical surface St1 on the injection hole 13 side is slightly separated from the end of the second conical surface St2 on the injection hole 13 side. On the other hand, the end of the first conical surface St1 on the side opposite to the injection hole 13 abuts against the end of the second conical surface St2 on the side opposite to the injection hole 13.

[0163] Therefore, it is possible to suppress the molten resin from entering between the first tapered surface St1 and the second tapered surface St2 from the side opposite to the nozzle hole 13 with respect to the upper case 70 during the molding process. Thus, it is possible to suppress the first tapered surface St1 and the second tapered surface St2 from separating.

[0164] In addition, in this embodiment, since an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 70 and the shell 20, the induced electromotive force generated by the behavior of the movable core 40 can be increased, and the controllability can be improved when the induced electromotive force is set as a signal.

[0165] As a control using the induced electromotive force as a signal, for example, an example of closing the valve of the probe needle 30 based on the detected induced electromotive force can be adopted (Japanese Patent Application Laid-Open No. 2017-061882).

[0166] As described above, in the present embodiment, the upper housing 70 has the first tapered surface St1 formed on the outer peripheral wall as one of the outer peripheral wall and the inner peripheral wall, and the first cylindrical surface Sc1 formed on the inner peripheral wall as the other of the outer peripheral wall and the inner peripheral wall. The housing 20 as one of the housing 20 and the fixed core 50 has the second tapered surface St2 facing the first tapered surface St1 in the radial direction. The fixed core 50 as the other of the housing 20 and the fixed core 50 has the second cylindrical surface Sc2 facing the first cylindrical surface Sc1 in the radial direction.

[0167] Therefore, by appropriately setting the diameters of the first conical surface St1, the second conical surface St2, the first cylindrical surface Sc1, and the second cylindrical surface Sc2 before assembling the upper shell 70, when assembling the upper shell 70, by inserting the upper shell 70 from the side opposite to the nozzle 13 relative to the coil 55 between the fixed core 50 and the shell 20, the first conical surface St1 and the second conical surface St2 can be axially slid while the upper shell 70 is deformed radially inward, so that the first cylindrical surface Sc1 and the second cylindrical surface Sc2 can be abutted and tightly adhered.

[0168] Thus, after the upper housing 70 is assembled, the first tapered surface St1 and the second tapered surface St2 are in close contact with each other, and the first cylindrical surface Sc1 and the second cylindrical surface Sc2 are in close contact with each other.

[0169] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 70 and the shell 20. Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. As a result, the power consumption of the fuel injection valve 1 can be reduced.

[0170] In addition, in the present embodiment, when the first conical surface St1 and the second conical surface St2 are not facing each other in the radial direction, the inner diameter of the first cylindrical surface Sc1 is larger than the outer diameter of the second cylindrical surface Sc2. When the first conical surface St1 and the second conical surface St2 are facing each other in the radial direction, the first cylindrical surface Sc1 and the second cylindrical surface Sc2 are in contact.

[0171] Therefore, when assembling the upper shell 70, the upper shell 70 can be easily inserted between the fixed core 50 and the housing 20 from the side opposite to the injection hole 13 with respect to the coil 55. In addition, after assembling the upper shell 70, the first conical surface St1 can be closely attached to the second conical surface St2, and the first cylindrical surface Sc1 can be closely attached to the second cylindrical surface Sc2. Thus, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 70, and the housing 20.

[0172] In addition, in the present embodiment, the second cylindrical surface Sc2 is formed on the fixed core 50 . The second tapered surface St2 is formed on the housing 20 .

[0173] Therefore, when assembling the upper case 70 , the upper case 70 can be deformed not toward the radially outer side, that is, the tension side, but toward the radially inner side, that is, the compression side. Thus, the strength of the upper case 70 can be ensured.

[0174] In addition, in the present embodiment, the end portion of the first tapered surface St1 on the injection hole 13 side is separated from the end portion of the second tapered surface St2 on the injection hole 13 side.

[0175] That is, in the present embodiment, the upper case 70 is provided so that the outer peripheral wall of the end portion on the injection hole 13 side is separated from the inner peripheral wall of the case 20 .

[0176] In the present embodiment, before the upper shell 70 is assembled to the inner side of the shell 20, the ratio of the diameter reduction of the first tapered surface St1 of the upper shell 70, i.e., the diameter reduction rate, is slightly larger than the diameter reduction rate of the second tapered surface St2 of the shell 20. Therefore, when the upper shell 70 is pressed into the inner side of the shell 20 in the upper shell assembly process, the outer peripheral wall of the end of the upper shell 70 on the side opposite to the injection hole 13 first contacts the inner peripheral wall of the shell 20. After the upper shell 70 is pressed into place, the outer peripheral wall (first tapered surface St1) of the end of the upper shell 70 on the injection hole 13 side is slightly separated from the inner peripheral wall (second tapered surface St2) of the shell 20.

[0177] Therefore, it is possible to prevent the molten resin from entering between the first tapered surface St1 of the upper shell 70 and the second tapered surface St2 of the shell 20 from the side opposite to the injection hole 13 relative to the upper shell 70 during the molding process. Thus, it is possible to prevent the first tapered surface St1 of the upper shell 70 and the second tapered surface St2 of the shell 20 from separating. Therefore, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be reliably formed in the fixed core 50, the upper shell 70, and the shell 20.

[0178] In addition, in the present embodiment, the upper case 70 has a cutout portion 72 in a portion in the circumferential direction, and is formed in a C-shape when viewed from the axial direction.

[0179] Therefore, the upper case 70 can be easily deformed radially inward when the upper case 70 is assembled. Thus, after the upper case 70 is assembled, the first cylindrical surface Sc1 and the second cylindrical surface Sc2 can be brought into closer contact with each other.

[0180] (Second embodiment)

[0181] Figure 7 1 shows a part of a fuel injection valve according to a second embodiment. The second embodiment is different from the first embodiment in the structure of an upper housing, a fixed core, and a housing.

[0182] In the present embodiment, the first tapered surface St1 is formed on the inner peripheral wall of the main body 71 of the upper shell 70. The first tapered surface St1 is formed in a tapered shape so as to approach the axis of the upper shell 70 at a predetermined ratio as it moves from the side of the injection hole 13 relative to the upper shell 70 toward the side opposite to the injection hole 13 (see Figure 7 ).

[0183] The first cylindrical surface Sc1 is formed on the outer peripheral wall of the main body 71 of the upper housing 70. The first cylindrical surface Sc1 is formed in a cylindrical surface shape centered on the axis of the upper housing 70 (see Figure 7 ).

[0184] like Figure 7 As shown, the fixed core 50 has a second tapered surface St2. The second tapered surface St2 is formed on the outer peripheral wall of the fixed core 50 in a manner that faces the first tapered surface St1 formed on the inner peripheral wall of the upper shell 70 in the radial direction. The second tapered surface St2 is formed in a tapered shape in a manner that approaches the axis of the fixed core 50 at a predetermined ratio as it moves from the injection hole 13 side of the axial direction of the fixed core 50 to the side opposite to the injection hole 13.

[0185] like Figure 7As shown, the housing 20 has a second cylindrical surface Sc2. The second cylindrical surface Sc2 is formed on the inner peripheral wall of the outer cylindrical portion 21 of the housing 20 in a manner that faces the first cylindrical surface Sc1 formed on the outer peripheral wall of the upper housing 70 in the radial direction. The second cylindrical surface Sc2 is formed into a cylindrical surface shape with the axis of the outer cylindrical portion 21 of the housing 20 as the center.

[0186] In addition, an annular step surface 205 is formed on the inner peripheral wall of the outer cylinder portion 21. The upper housing 70 does not come into contact with the step surface 205.

[0187] Next, a method of assembling the upper case 70 between the fixed core 50 and the case 20 will be described.

[0188] The “housing assembly process”, “coil assembly process” and “molding process” in the method for manufacturing the fuel injection valve 1 of the present embodiment are the same as those of the first embodiment, and thus descriptions thereof are omitted, and only the “upper housing assembly process” is described below.

[0189] (Upper housing assembly process)

[0190] After the coil assembly process, the upper shell 70 is inserted between the fixed core 50 and the shell 20. Specifically, the upper shell 70 is inserted from the side of the fixed core 50 opposite to the nozzle hole 13, and the coil frame extension part 552 is located in the cutout part 72 of the upper shell 70, and the upper shell 70 is pressed into the outside of the fixed core 50.

[0191] like Figure 8 As shown in FIG. 1 , when the upper shell 70 is pressed into the outside of the fixed core 50, first, the inner circumferential wall of the upper shell 70, i.e., the first conical surface St1, faces the outer circumferential wall of the fixed core 50 in the radial direction on the side opposite to the injection hole 13 relative to the second conical surface St2. In this state, i.e., the state in which the first conical surface St1 and the second conical surface St2 do not face each other in the radial direction, the outer diameter of the first cylindrical surface Sc1 is smaller than the inner diameter of the second cylindrical surface Sc2. Therefore, in at least a part of the circumference of the upper shell 70, a gap Sp1 is formed between the outer circumferential wall of the upper shell 70, i.e., the first cylindrical surface Sc1, and the inner circumferential wall of the housing 20.

[0192] In this state, that is, the state in which the first tapered surface St1 and the second tapered surface St2 do not face each other in the radial direction, the inner diameter of the end of the first tapered surface St1 on the injection hole 13 side is smaller than the outer diameter of the end of the second tapered surface St2 on the injection hole 13 side.

[0193] In this state, when the upper shell 70 is further moved toward the injection hole 13, the first conical surface St1 of the upper shell 70 contacts and slides with the second conical surface St2 of the fixed core 50. At this time, the upper shell 70 is deformed radially outward in a manner that the inner diameter and the outer diameter are enlarged. Therefore, the first cylindrical surface Sc1 of the upper shell 70 abuts against and fits tightly against the second cylindrical surface Sc2 of the shell 20. As a result, after the upper shell 70 is assembled, the first conical surface St1 fits tightly against the second conical surface St2, and the first cylindrical surface Sc1 fits tightly against the second cylindrical surface Sc2 (see Figure 7 , Figure 8 ).

[0194] As described above, in the present embodiment, the upper housing 70 has the first tapered surface St1 formed on the inner peripheral wall as one of the outer peripheral wall and the inner peripheral wall, and the first cylindrical surface Sc1 formed on the outer peripheral wall as the other of the outer peripheral wall and the inner peripheral wall. The fixed core 50 as one of the housing 20 and the fixed core 50 has the second tapered surface St2 facing the first tapered surface St1 in the radial direction. The housing 20 as the other of the housing 20 and the fixed core 50 has the second cylindrical surface Sc2 facing the first cylindrical surface Sc1 in the radial direction.

[0195] Therefore, by appropriately setting the diameters of the first conical surface St1, the second conical surface St2, the first cylindrical surface Sc1, and the second cylindrical surface Sc2 before assembling the upper shell 70, when assembling the upper shell 70, by inserting the upper shell 70 from the side opposite to the nozzle 13 relative to the coil 55 between the fixed core 50 and the shell 20, the first conical surface St1 and the second conical surface St2 can be axially slid while the upper shell 70 is deformed radially outward, so that the first cylindrical surface Sc1 and the second cylindrical surface Sc2 can be abutted and tightly attached.

[0196] Thus, after the upper housing 70 is assembled, the first tapered surface St1 and the second tapered surface St2 are in close contact with each other, and the first cylindrical surface Sc1 and the second cylindrical surface Sc2 are in close contact with each other.

[0197] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 70 and the shell 20. Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. As a result, the power consumption of the fuel injection valve 1 can be reduced.

[0198] In addition, when the axial length of the inner edge of the upper shell 70 is the same as the axial length of the outer edge of the upper shell 70 as in the present embodiment, the area of ​​the magnetic circuit formed on the inner peripheral wall of the upper shell 70 is smaller than the area of ​​the magnetic circuit formed on the outer peripheral wall of the upper shell 70. In the present embodiment, the upper shell 70 is pressed into the fixed core 50 while sliding the inner peripheral wall of the upper shell 70, i.e., the first conical surface St1, and the outer peripheral wall of the fixed core 50, i.e., the second conical surface St2. Therefore, the inner peripheral wall of the upper shell 70, which is the pressed side, is stably in close contact with the outer peripheral wall of the fixed core 50. Thus, it is easy to ensure the magnetic circuit area of ​​the inner peripheral wall, which is the side with the smaller magnetic circuit area, between the inner peripheral wall and the outer peripheral wall of the upper shell 70. The present embodiment is advantageous over the first embodiment in this respect.

[0199] In addition, in the present embodiment, when the first conical surface St1 and the second conical surface St2 are not facing each other in the radial direction, the outer diameter of the first cylindrical surface Sc1 is smaller than the inner diameter of the second cylindrical surface Sc2. When the first conical surface St1 and the second conical surface St2 are facing each other in the radial direction, the first cylindrical surface Sc1 and the second cylindrical surface Sc2 are in contact.

[0200] Therefore, when assembling the upper shell 70, the upper shell 70 can be easily inserted between the fixed core 50 and the housing 20 from the side opposite to the injection hole 13 with respect to the coil 55. In addition, after assembling the upper shell 70, the first conical surface St1 can be closely attached to the second conical surface St2, and the first cylindrical surface Sc1 can be closely attached to the second cylindrical surface Sc2. Thus, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 70, and the housing 20.

[0201] In addition, in the present embodiment, the end portion of the first tapered surface St1 on the injection hole 13 side is separated from the end portion of the second tapered surface St2 on the injection hole 13 side.

[0202] That is, in the present embodiment, the upper case 70 is provided so that the inner peripheral wall of the end portion on the injection hole 13 side is separated from the outer peripheral wall of the fixed core 50 .

[0203] In the present embodiment, before the upper shell 70 is assembled to the outside of the fixed core 50, the ratio of the diameter reduction of the first tapered surface St1 of the upper shell 70, i.e., the diameter reduction rate, is slightly larger than the diameter reduction rate of the second tapered surface St2 of the fixed core 50. Therefore, when the upper shell 70 is pressed into the outside of the fixed core 50 in the upper shell assembly process, the inner peripheral wall of the end portion of the upper shell 70 on the side opposite to the injection hole 13 first contacts the outer peripheral wall of the fixed core 50. After the upper shell 70 is pressed into place, the inner peripheral wall (first tapered surface St1) of the end portion of the upper shell 70 on the injection hole 13 side is slightly separated from the outer peripheral wall (second tapered surface St2) of the fixed core 50.

[0204] Therefore, it is possible to prevent the molten resin from entering between the first tapered surface St1 of the upper shell 70 and the second tapered surface St2 of the fixed core 50 from the side opposite to the injection hole 13 relative to the upper shell 70 during the molding process. As a result, it is possible to prevent the first tapered surface St1 of the upper shell 70 and the second tapered surface St2 of the fixed core 50 from being separated. Therefore, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be reliably formed in the fixed core 50, the upper shell 70, and the shell 20.

[0205] (Third embodiment)

[0206] Fig. 9 1 shows a part of a fuel injection valve according to a third embodiment. The third embodiment is different from the first embodiment in the structure of an upper housing, a fixed core, and a housing.

[0207] In the present embodiment, the upper case 80 includes an inner member 81 and an outer member 85 .

[0208] The inner member 81 and the outer member 85 are each formed of a magnetic material such as metal into a substantially C-shape (see Fig.10 , Fig.11 ).

[0209] like Fig. 9 As shown, the upper shell 80 is provided between the fixed core 50 and the shell 20, on the side opposite to the injection hole 13 with respect to the coil 55. Here, the inner peripheral wall of the inner member 81 of the upper shell 80 is in close contact with the outer peripheral wall of the fixed core 50. In addition, the outer peripheral wall of the inner member 81 is in close contact with the inner peripheral wall of the outer member 85. Furthermore, the outer peripheral wall of the outer member 85 of the upper shell 80 is in close contact with the inner peripheral wall of the outer cylinder portion 21 of the shell 20.

[0210] When the coil 55 is supplied with power (energized), a magnetic force is generated. When a magnetic force is generated in the coil 55, a magnetic circuit is formed in the fixed core 50, the upper shell 80, the outer cylinder 21, the outer annular portion 22, the nozzle cylinder 12, and the movable core 40, avoiding the magnetic throttling portion 15 (refer to Fig. 9 ).

[0211] Next, the upper housing 80 will be described in more detail.

[0212] like Fig.10 As shown, the inner member 81 includes an inner member body 82 and a cutout portion 83 .

[0213] The inner member body 82 is formed into an annular shape by, for example, a magnetic material such as metal. The cutout portion 83 is formed by cutting off a portion of the circumferential direction of the inner member body 82. Thus, a portion of the circumferential direction of the inner member body 82 of the upper housing 80 is cut off, forming a C-shape when viewed from the axial direction.

[0214] like Fig.11 As shown, the outer member 85 includes an outer member body 86 , a cutout portion 87 , and a recessed portion 88 .

[0215] The outer member body 86 is formed into an annular shape by, for example, a magnetic material such as metal. The cutout portion 87 is formed by cutting off a portion of the circumferential direction of the outer member body 86. Thus, a portion of the circumferential direction of the outer member body 86 of the upper housing 80 is cut off, forming a C-shape when viewed from the axial direction.

[0216] The recessed portion 88 is formed so as to be recessed radially inward from the outer peripheral wall of the outer member body 86. Five recessed portions 88 are formed at equal intervals in the circumferential direction of the outer member body 86. By forming the recessed portions 88 in the outer member body 86, the outer member body 86 can be easily deformed in the radial direction.

[0217] With the above-described structure, the inner member 81 and the outer member 85 of the upper housing 80 have the cutout portions 83 and 87 in a portion in the circumferential direction, and are formed into a C-shape when viewed from the axial direction.

[0218] The inner member 81 of the upper case 80 has a first tapered surface St1 and a first cylindrical surface Sc1.

[0219] Fig.10 FIG. 2 shows the inner member 81 of the upper housing 80 before being assembled between the fixed core 50 and the housing 20. The first tapered surface St1 is formed on the outer peripheral wall of the inner member body 82 of the upper housing 80. The first tapered surface St1 is located on a virtual tapered surface Stv1 centered on the axis of the inner member body 82 of the upper housing 80 (see FIG. 2 ). Fig.10 Here, the virtual tapered surface Stv1 is a tapered virtual surface that approaches the axis of the inner member body 82 at a predetermined ratio as it goes from one side to the other side in the axial direction of the inner member body 82 .

[0220] The first tapered surface St1 is formed in a tapered shape so as to approach the axis of the upper housing 80 at a predetermined ratio as it moves from the side opposite to the injection hole 13 with respect to the upper housing 80 toward the injection hole 13 (see Fig. 9 , Fig.10 ).

[0221] The first cylindrical surface Sc1 is formed on the inner peripheral wall of the inner member body 82 of the upper housing 80. The first cylindrical surface Sc1 is located on a virtual cylindrical surface Scv1 centered on the axis of the inner member body 82 of the upper housing 80 (see Fig.10 Here, the virtual cylindrical surface Scv1 is a cylindrical virtual surface having a constant distance from the axis of the inner member body 82 in the axial direction of the inner member body 82 .

[0222] The first cylindrical surface Sc1 is formed in a cylindrical surface shape with the axis of the upper housing 80 as the center (see Fig. 9 , Fig.10 ).

[0223] The outer member 85 of the upper housing 80 has a second tapered surface St2 and a second cylindrical surface Sc2.

[0224] Fig.11 FIG. 2 shows the outer member 85 of the upper housing 80 before being assembled between the fixed core 50 and the housing 20. The second conical surface St2 is formed on the inner peripheral wall of the outer member 85 of the upper housing 80. The second conical surface St2 is located on a virtual conical surface Stv2 centered on the axis of the outer member main body 86 of the upper housing 80 (see FIG. 2 ). Fig.11 Here, the virtual tapered surface Stv2 is a tapered virtual surface that approaches the axis of the outer member body 86 at a predetermined ratio as it goes from one side to the other side in the axial direction of the outer member body 86.

[0225] The second tapered surface St2 is formed in a tapered shape so as to approach the axis of the upper shell 80 at a predetermined ratio as it moves from the side opposite to the injection hole 13 with respect to the upper shell 80 toward the injection hole 13 (see Fig. 9 , Fig.11 ).

[0226] The second cylindrical surface Sc2 is formed on the outer peripheral wall of the outer member body 86 of the upper shell 80. The second cylindrical surface Sc2 is located on a virtual cylindrical surface Scv2 centered on the axis of the outer member body 86 of the upper shell 80 (see Fig.11 Here, the virtual cylindrical surface Scv2 is a cylindrical virtual surface having a constant distance from the axis of the outer member body 86 in the axial direction of the outer member body 86 .

[0227] like Fig.12 As shown, the axial length L1 of the inner member 81 is greater than the axial length L2 of the outer member 85 .

[0228] like Fig. 9 As shown in FIG. 1 , the end surface of the inner member 81 on the injection hole 13 side is located on the injection hole 13 side relative to the end surface of the outer member 85 on the injection hole 13 side. In addition, the end surface of the inner member 81 on the side opposite to the injection hole 13 is located on the side opposite to the injection hole 13 relative to the end surface of the outer member 85 on the side opposite to the injection hole 13. That is, the outer member 85 is located within the range of the axial length of the inner member 81 in the axial direction.

[0229] like Fig. 9 As shown, the fixed core 50 has a third cylindrical surface Sc3. The third cylindrical surface Sc3 is formed on the outer peripheral wall of the fixed core 50 in a manner facing the first cylindrical surface Sc1 of the inner member 81 in the radial direction. The third cylindrical surface Sc3 is formed into a cylindrical surface shape centered on the axis of the fixed core 50 (see Fig. 9 ).

[0230] like Fig. 9 As shown, the housing 20 has a fourth cylindrical surface Sc4. The fourth cylindrical surface Sc4 is formed on the inner peripheral wall of the outer cylinder portion 21 of the housing 20 in a manner facing the second cylindrical surface Sc2 of the outer member 85 in the radial direction. The fourth cylindrical surface Sc4 is formed into a cylindrical surface shape centered on the axis of the outer cylinder portion 21 (see Fig. 9 ).

[0231] In addition, an annular step surface 205 is formed on the inner peripheral wall of the outer cylinder portion 21. The outer member 85 of the upper housing 80 abuts against the step surface 205, and movement toward the injection hole 13 side is restricted.

[0232] Next, a method of assembling the upper case 80 between the fixed core 50 and the case 20 will be described.

[0233] The “housing assembly process”, “coil assembly process” and “molding process” in the method for manufacturing the fuel injection valve 1 of the present embodiment are the same as those of the first embodiment, and thus descriptions thereof are omitted, and only the “upper housing assembly process” is described below.

[0234] (Upper housing assembly process)

[0235] After the coil assembly process, the upper housing 80 is inserted between the fixed core 50 and the housing 20. Specifically, first, the outer member 85 of the upper housing 80 is inserted from the side of the fixed core 50 opposite to the nozzle hole 13, and the coil frame extension portion 552 is located at the cutout portion 87 of the outer member 85, and then the outer member 85 is inserted or pressed into the inner side of the outer cylinder portion 21 of the housing 20. As a result, the outer member 85 abuts against the step surface 205, and is restricted from moving toward the nozzle hole 13 side.

[0236] Thereafter, the inner member 81 of the upper case 80 is inserted from the side of the fixed core 50 opposite to the injection hole 13 , and the inner member 81 is pressed into the inner side of the outer member 85 with the bobbin extension 552 positioned in the cutout 83 of the inner member 81 .

[0237] like Fig.13 As shown in FIG. 1 , when the inner member 81 is pressed into the inner side of the outer member 85, first, the outer peripheral wall of the inner member 81, i.e., the first conical surface St1, faces the inner peripheral wall of the outer cylindrical portion 21 of the housing 20 in the radial direction on the side opposite to the injection hole 13 relative to the second conical surface St2. In this state, i.e., the state in which the first conical surface St1 and the second conical surface St2 do not face each other in the radial direction, the inner diameter of the first cylindrical surface Sc1 is larger than the outer diameter of the third cylindrical surface Sc3. Therefore, in at least a portion of the circumference of the inner member 81 of the upper housing 80, a gap Sp1 is formed between the inner peripheral wall of the inner member 81, i.e., the first cylindrical surface Sc1, and the outer peripheral wall of the fixed core 50.

[0238] In this state, that is, the state in which the first tapered surface St1 and the second tapered surface St2 do not face each other in the radial direction, the outer diameter of the end of the first tapered surface St1 on the injection hole 13 side is larger than the inner diameter of the end of the second tapered surface St2 on the injection hole 13 side.

[0239] In this state, when the inner member 81 is further moved toward the injection hole 13, the first tapered surface St1 of the inner member 81 contacts and slides with the second tapered surface St2 of the outer member 85. At this time, the inner member 81 is deformed radially inwardly in such a manner that the inner diameter and the outer diameter are reduced. Therefore, the first cylindrical surface Sc1 of the inner member 81 contacts and closely adheres to the third cylindrical surface Sc3 of the fixed core 50.

[0240] At this time, the outer member 85 is deformed radially outward so that the inner diameter and the outer diameter are enlarged. Therefore, the second cylindrical surface Sc2 of the outer member 85 and the fourth cylindrical surface Sc4 of the housing 20 are in close contact.

[0241] Thus, after the upper housing 80 is assembled, the first tapered surface St1 and the second tapered surface St2 are in close contact with each other, the first cylindrical surface Sc1 and the third cylindrical surface Sc3 are in close contact with each other, and the second cylindrical surface Sc2 and the fourth cylindrical surface Sc4 are in close contact with each other (see Fig. 9 , Fig.13 ).

[0242] In addition, the inner member 81 is not press-fitted to a predetermined dimension but is managed by load. Thus, it is possible to suppress the deviation of the first tapered surface St1 and the second tapered surface St2 that occurs when both the outer member 85 and the inner member 81 are press-fitted to a predetermined dimension.

[0243] like Fig.10 , Fig.11 As shown in FIG. 1 , before the upper case 80 is assembled between the fixed core 50 and the case 20, the angle θ1 formed by the straight line connecting the axis of the inner member 81 and the two ends of the cutout portion 83 is greater than the angle θ2 formed by the straight line connecting the axis of the outer member 85 and the two ends of the cutout portion 87. Fig. 9 , Fig.13 ), the angle θ1 formed by the straight line connecting the axis of the inner member 81 and the two ends of the cutout portion 83 is the same as the angle θ2 formed by the straight line connecting the axis of the outer member 85 and the two ends of the cutout portion 87.

[0244] In the present embodiment, when the hardness of the fixed core 50 is set to H1, the hardness of the inner member 81 is set to H2, the hardness of the outer member 85 is set to H3, and the hardness of the housing 20 is set to H4, the fixed core 50, the inner member 81, the outer member 85, and the housing 20 are formed, for example, by heat treatment to satisfy the relationship of H1, H4>H2, H3. Therefore, when the upper housing 80 is assembled between the fixed core 50 and the housing 20, the inner member 81 and the outer member 85 can be easily deformed in the radial direction.

[0245] Next, the present embodiment will be compared with the second comparative embodiment, and the technical advantages of the present embodiment over the second comparative embodiment will be described.

[0246] The second comparative embodiment is different from the first comparative embodiment in that it further includes a magnetic material ring 79. The magnetic material ring 79 is formed of a magnetic material such as metal in a substantially C-shape. The magnetic material ring 79 is provided between the fixed core 50 and the housing 20 on the side opposite to the injection hole 13 with respect to the upper housing 70.

[0247] Before assembly, the inner diameter of the magnetic material ring 79 is smaller than the outer diameter of the fixed core 50, and the outer diameter is smaller than the inner diameter of the outer cylinder portion 21 of the housing 20. Therefore, during assembly, the magnetic material ring 79 is pressed in with the inner peripheral wall in contact with the outer peripheral wall of the fixed core 50. Here, the magnetic material ring 79 is pushed in until it abuts against the upper housing 70.

[0248] In the second comparative embodiment, springback may occur when the magnetic material ring 79 is pressed in. Therefore, after the magnetic material ring 79 is assembled, a gap serving as a magnetic gap may be formed between the end surface of the upper shell 70 on the magnetic material ring 79 side and the end surface of the magnetic material ring 79 on the upper shell 70 side.

[0249] Therefore, when the coil 55 is energized, it may be difficult to form an efficient magnetic circuit with a small magnetic gap and magnetic resistance in the fixed core 50, the magnetic material ring 79, the upper shell 70, and the shell 20. In this case, it may be difficult to efficiently generate an attractive force for the current input to the coil 55. Therefore, the energy required to drive the fuel injection valve may increase.

[0250] On the other hand, in the present embodiment, the inner member 81 of the upper shell 80 has a first conical surface St1, and the outer member 85 of the upper shell 80 has a second conical surface St2, whereby after the upper shell 80 is assembled, the first conical surface St1 of the inner member 81 is in close contact with the second conical surface St2 of the outer member 85, and the first cylindrical surface Sc1 of the inner member 81 is in close contact with the third cylindrical surface Sc3 of the fixed core 50, and the second cylindrical surface Sc2 of the outer member 85 is in close contact with the fourth cylindrical surface Sc4 of the shell 20.

[0251] Furthermore, in the present embodiment, springback does not occur when the inner member 81 is pressed in, and the inner member 81 can be kept in close contact with the fixed core 50 and the outer member 85 .

[0252] Therefore, when the coil 55 is energized, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the inner member 81 and the outer member 85 of the upper housing 80, and the housing 20 (see Fig. 9 ). Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. Thus, the power consumption of the fuel injection valve 1 can be reduced.

[0253] In addition, in this embodiment, the outer member 85 of the upper shell 80 abuts against the step surface 205 of the shell 20 and is restricted from moving toward the nozzle hole 13. Therefore, even if the inner member 81 is pressed into the inner side of the outer member 85, the distance between the outer member 85 and the coil frame 551 can be kept fixed.

[0254] In addition, in the present embodiment, before the inner member 81 is assembled to the inner side of the outer member 85, the ratio of the reduction in diameter of the first tapered surface St1 of the inner member 81, i.e., the reduction rate, is slightly larger than the reduction rate of the second tapered surface St2 of the outer member 85. Therefore, when the inner member 81 is pressed into the inner side of the outer member 85 in the upper shell assembly process, the outer peripheral wall of the end portion of the inner member 81 on the side opposite to the injection hole 13 contacts the inner peripheral wall of the outer member 85 first.

[0255] As described above, in this embodiment, the upper shell 80 has the inner member 81 and the outer member 85 provided radially outside the inner member 81. The inner member 81 has the first tapered surface St1 formed on the outer peripheral wall and the first cylindrical surface Sc1 formed on the inner peripheral wall. The outer member 85 has the second tapered surface St2 formed on the inner peripheral wall in a manner facing the first tapered surface St1 in the radial direction and the second cylindrical surface Sc2 formed on the outer peripheral wall. The fixed core 50 has the third cylindrical surface Sc3 facing the first cylindrical surface Sc1 in the radial direction. The housing 20 has the fourth cylindrical surface Sc4 facing the second cylindrical surface Sc2 in the radial direction.

[0256] Therefore, by appropriately setting the diameters of the first conical surface St1, the second conical surface St2, the first cylindrical surface Sc1, the second cylindrical surface Sc2, the third cylindrical surface Sc3, and the fourth cylindrical surface Sc4 before assembling the upper shell 80, when assembling the upper shell 80, by inserting the inner member 81 between the fixed core 50 and the shell 20 from the side opposite to the injection hole 13 relative to the coil 55, the first conical surface St1 and the second conical surface St2 can be axially slid while the inner member 81 is deformed radially inwardly so that the first cylindrical surface Sc1 and the third cylindrical surface Sc3 can be abutted and tightly attached, and the outer member 85 can be deformed radially outward so that the second cylindrical surface Sc2 and the fourth cylindrical surface Sc4 can be abutted and tightly attached.

[0257] Thus, after the upper housing 80 is assembled, the first tapered surface St1 and the second tapered surface St2 are in close contact with each other, the first cylindrical surface Sc1 and the third cylindrical surface Sc3 are in close contact with each other, and the second cylindrical surface Sc2 and the fourth cylindrical surface Sc4 are in close contact with each other.

[0258] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 80 and the shell 20. Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. As a result, the power consumption of the fuel injection valve 1 can be reduced.

[0259] In addition, in the present embodiment, by forming the upper shell 80 by two components, the inner member 81 and the outer member 85, the radial size of each component, that is, the width, can be reduced. Therefore, when assembling the upper shell 80, the inner member 81 and the outer member 85 of the upper shell 80 can be easily deformed in the radial direction. As a result, the assembly load of the upper shell 80 is reduced, and the assemblability can be improved. In addition, after the upper shell 80 is assembled, the first conical surface St1 and the second conical surface St2 are more closely attached, and the first cylindrical surface Sc1 and the third cylindrical surface Sc3 are more closely attached, and the second cylindrical surface Sc2 and the fourth cylindrical surface Sc4 are more closely attached.

[0260] In addition, in the present embodiment, when the first conical surface St1 and the second conical surface St2 are not facing each other in the radial direction, the inner diameter of the first cylindrical surface Sc1 is larger than the outer diameter of the third cylindrical surface Sc3. When the first conical surface St1 and the second conical surface St2 are facing each other in the radial direction, the first cylindrical surface Sc1 and the third cylindrical surface Sc3 are in contact.

[0261] Therefore, when assembling the upper shell 80, the inner member 81 can be easily inserted into the radially outer side of the fixed core 50 from the side opposite to the injection hole 13 with respect to the coil 55. In addition, after assembling the upper shell 80, the first conical surface St1 can be closely attached to the second conical surface St2, and the first cylindrical surface Sc1 can be closely attached to the third cylindrical surface Sc3. Thus, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 80, and the shell 20.

[0262] In addition, in the present embodiment, the axial length of the inner member 81 is greater than the axial length of the outer member 85 .

[0263] If the axial length of the inner member 81 is the same as the axial length of the outer member 85, the area of ​​the magnetic circuit formed on the inner peripheral wall of the inner member 81 is smaller than the area of ​​the magnetic circuit formed on the outer peripheral wall of the outer member 85. In the present embodiment, since the axial length of the inner member 81 is greater than the axial length of the outer member 85, the area of ​​the magnetic circuit formed on the inner peripheral wall of the inner member 81 can be made equal to the area of ​​the magnetic circuit formed on the outer peripheral wall of the outer member 85. Thus, a more efficient magnetic circuit can be formed in the fixed core 50, the upper shell 80, and the shell 20.

[0264] In addition, the end surface of the inner member 81 on the injection hole 13 side is located on the injection hole 13 side relative to the end surface of the outer member 85 on the injection hole 13 side. Furthermore, the end surface of the inner member 81 on the side opposite to the injection hole 13 is located on the side opposite to the injection hole 13 relative to the end surface of the outer member 85 on the side opposite to the injection hole 13. That is, the outer member 85 is located within the range of the axial length of the inner member 81 in the axial direction.

[0265] Therefore, the contact length between the first tapered surface St1 and the second tapered surface St2 in the axial direction can be ensured to the maximum extent, and the area of ​​the magnetic path between the first tapered surface St1 and the second tapered surface St2 can be ensured to the maximum extent.

[0266] (Fourth embodiment)

[0267] Fig.15 1 shows a part of a fuel injection valve according to a fourth embodiment. The fourth embodiment is different from the third embodiment in the structure of an upper housing 80 and a fixed core 50 .

[0268] In the present embodiment, the first tapered surface St1 and the second tapered surface St2 are formed in a tapered shape so as to approach the axis of the upper shell 80 at a predetermined ratio as they go from the injection hole 13 side relative to the upper shell 80 to the side opposite to the injection hole 13 (see Fig.15 ).

[0269] An annular stepped surface 505 is formed on the outer peripheral wall of the stationary core 50. The inner member 81 of the upper housing 80 abuts against the stepped surface 505, and movement toward the injection hole 13 side is restricted.

[0270] Next, a method of assembling the upper case 80 between the fixed core 50 and the case 20 will be described.

[0271] (Upper housing assembly process)

[0272] After the coil assembly process, the upper case 80 is inserted between the fixed core 50 and the case 20. Specifically, first, the inner member 81 of the upper case 80 is inserted from the side of the fixed core 50 opposite to the injection hole 13, and the inner member 81 is pressed into the outer side of the fixed core 50 in a state where the coil frame extension portion 552 is located at the cutout portion 83 of the inner member 81. As a result, the inner member 81 abuts against the step surface 505 and is restricted from moving toward the injection hole 13 side.

[0273] Thereafter, the outer member 85 of the upper case 80 is inserted from the side of the fixed core 50 opposite to the injection hole 13 , and the outer member 85 is press-fitted to the outside of the inner member 81 with the bobbin extension 552 positioned in the cutout 87 of the outer member 85 .

[0274] like Fig.16 As shown in FIG. 1 , when the outer member 85 is pressed into the outer side of the inner member 81, first, the inner peripheral wall of the outer member 85, i.e., the second conical surface St2, faces the outer peripheral wall of the fixed core 50 in the radial direction on the side opposite to the injection hole 13 relative to the first conical surface St1. In this state, i.e., the state in which the first conical surface St1 and the second conical surface St2 do not face each other in the radial direction, the outer diameter of the second cylindrical surface Sc2 is smaller than the inner diameter of the fourth cylindrical surface Sc4. Therefore, in at least a part of the circumference of the outer member 85 of the upper shell 80, a gap Sp1 is formed between the outer peripheral wall of the outer member 85, i.e., the second cylindrical surface Sc2, and the inner peripheral wall of the outer cylinder portion 21 of the shell 20.

[0275] In this state, that is, the state in which the first tapered surface St1 and the second tapered surface St2 do not face each other in the radial direction, the inner diameter of the end of the second tapered surface St2 on the injection hole 13 side is smaller than the outer diameter of the end of the first tapered surface St1 on the injection hole 13 side.

[0276] In this state, when the outer member 85 is further moved toward the injection hole 13, the second conical surface St2 of the outer member 85 contacts and slides with the first conical surface St1 of the inner member 81. At this time, the outer member 85 is deformed radially outward in such a way that the inner diameter and the outer diameter are enlarged. Therefore, the second cylindrical surface Sc2 of the outer member 85 contacts and closely adheres to the fourth cylindrical surface Sc4 of the housing 20.

[0277] At this time, the inner member 81 is deformed radially inward so that the inner diameter and the outer diameter are reduced. Therefore, the first cylindrical surface Sc1 of the inner member 81 and the third cylindrical surface Sc3 of the fixed core 50 are in close contact.

[0278] Thus, after the upper housing 80 is assembled, the first tapered surface St1 and the second tapered surface St2 are in close contact with each other, the first cylindrical surface Sc1 and the third cylindrical surface Sc3 are in close contact with each other, and the second cylindrical surface Sc2 and the fourth cylindrical surface Sc4 are in close contact with each other (see Fig.15 , Fig.16 ).

[0279] In addition, in this embodiment, the inner member 81 of the upper shell 80 abuts against the step surface 505 of the fixed core 50, and is restricted from moving toward the injection hole 13. Therefore, even if the outer member 85 is pressed to the outside of the inner member 81, the distance between the inner member 81 and the coil frame 551 can be kept fixed.

[0280] In addition, in the present embodiment, before the outer member 85 is assembled to the outer side of the inner member 81, the reduction ratio of the second tapered surface St2 of the outer member 85, i.e., the reduction ratio, is slightly larger than the reduction ratio of the first tapered surface St1 of the inner member 81. Therefore, when the outer member 85 is pressed into the outer side of the inner member 81 in the upper shell assembly process, the inner peripheral wall of the end portion of the outer member 85 on the side opposite to the injection hole 13 contacts the outer peripheral wall of the inner member 81 first.

[0281] As described above, in this embodiment, by appropriately setting the diameters of the first conical surface St1, the second conical surface St2, the first cylindrical surface Sc1, the second cylindrical surface Sc2, the third cylindrical surface Sc3, and the fourth cylindrical surface Sc4 before assembling the upper shell 80, when assembling the upper shell 80, by inserting the outer member 85 between the inner member 81 and the shell 20 from the side opposite to the injection hole 13 relative to the coil 55 while the inner member 81 is inserted between the fixed core 50 and the shell 20, the first conical surface St1 and the second conical surface St2 can be axially slid while the outer member 85 is deformed radially outward so that the second cylindrical surface Sc2 and the fourth cylindrical surface Sc4 can be abutted and tightly attached, and the inner member 81 can be deformed radially inward so that the first cylindrical surface Sc1 and the third cylindrical surface Sc3 can be abutted and tightly attached.

[0282] Thus, after the upper housing 80 is assembled, the first tapered surface St1 and the second tapered surface St2 are in close contact with each other, the first cylindrical surface Sc1 and the third cylindrical surface Sc3 are in close contact with each other, and the second cylindrical surface Sc2 and the fourth cylindrical surface Sc4 are in close contact with each other.

[0283] Therefore, similarly to the third embodiment, an efficient magnetic path with a small magnetic gap and magnetic resistance can be formed in the fixed core 50 , the upper case 80 , and the case 20 .

[0284] Furthermore, in the present embodiment, when the upper housing 80 is assembled, the inner member 81 is pressed into the fixed core 50. Therefore, the inner peripheral wall of the inner member 81, which is the pressed-in side, is stably in close contact with the outer peripheral wall of the fixed core 50. Thus, it is easy to ensure the magnetic path area of ​​the inner peripheral wall of the inner member 81, which is the side with a smaller magnetic path area, between the inner peripheral wall of the inner member 81 of the upper housing 80 and the outer peripheral wall of the outer member 85.

[0285] In addition, in the present embodiment, when the first conical surface St1 and the second conical surface St2 are not facing each other in the radial direction, the outer diameter of the second cylindrical surface Sc2 is smaller than the inner diameter of the fourth cylindrical surface Sc4. When the first conical surface St1 and the second conical surface St2 are facing each other in the radial direction, the second cylindrical surface Sc2 abuts against the fourth cylindrical surface Sc4.

[0286] Therefore, when assembling the upper shell 80, the outer member 85 can be easily inserted into the radial inner side of the outer cylinder portion 21 of the shell 20 from the side opposite to the injection hole 13 relative to the coil 55. In addition, after assembling the upper shell 80, the first conical surface St1 can be closely attached to the second conical surface St2, and the second cylindrical surface Sc2 can be closely attached to the fourth cylindrical surface Sc4. Thus, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 80, and the shell 20.

[0287] (Fifth embodiment)

[0288] Fig.17 1 shows a part of a fuel injection valve according to a fifth embodiment. The fifth embodiment is different from the third embodiment in the structure of an upper housing and the like.

[0289] In the present embodiment, the upper case 90 has a bottom portion 91 , an inner extension portion 92 , and an outer extension portion 93 .

[0290] The bottom 91, the inner extension 92, and the outer extension 93 are integrally formed of a magnetic material such as metal. The bottom 91 is formed in a substantially C-shaped shape. The inner extension 92 is formed in a substantially C-shaped cylindrical shape in a manner extending from the inner edge of the bottom 91 to the axial direction of the bottom 91. The outer extension 93 is formed in a substantially C-shaped cylindrical shape in a manner extending from the outer edge of the bottom 91 to the axial direction of the bottom 91. The upper shell 90 has a cutout portion in a portion of the circumferential direction, and is formed in a C-shaped shape when viewed from the axial direction.

[0291] Here, a substantially C-shaped groove 900 is formed between the inner extension portion 92 and the outer extension portion 93. In addition, a recess 94 recessed radially inward from the outer peripheral wall is formed in the outer extension portion 93. For example, five recesses 94 are formed at equal intervals in the circumferential direction of the outer extension portion 93.

[0292] The upper case 90 is provided between the fixed core 50 and the case 20 on the opposite side of the coil 55 from the injection hole 13. Here, the outer edge of the bottom 91 of the upper case 90 contacts the stepped surface 205 of the case 20.

[0293] The present embodiment further includes an intermediate member 95. The intermediate member 95 is formed into a substantially C-shaped cylindrical shape by a magnetic material such as metal, for example. The inner peripheral wall of the intermediate member 95 is formed into a tapered shape so as to approach the axis of the intermediate member 95 at a predetermined ratio as it goes from one side of the axial direction of the intermediate member 95 to the other side. The outer peripheral wall of the intermediate member 95 is formed into a tapered shape so as to be away from the axis of the intermediate member 95 at a predetermined ratio as it goes from one side of the axial direction of the intermediate member 95 to the other side.

[0294] The intermediate member 95 is provided between the inner extension portion 92 and the outer extension portion 93 of the upper shell 90, that is, in the groove portion 900. Here, the intermediate member 95 is provided so that the end face of the one with a narrower radial length, that is, a narrower width, of the two end faces in the axial direction faces the bottom 91. In addition, when one end face of the intermediate member 95 is in contact with the bottom 91, the other end face is located on the side opposite to the injection hole 13 with respect to the end faces of the inner extension portion 92 and the outer extension portion 93 of the upper shell 90 on the side opposite to the bottom 91.

[0295] When disposed between the inner extension portion 92 and the outer extension portion 93 , the intermediate member 95 can bias the inner extension portion 92 of the upper shell 90 radially inward of the bottom portion 91 , and can bias the outer extension portion 93 of the upper shell 90 radially outward of the bottom portion 91 .

[0296] Therefore, if Fig.17 As shown, when the intermediate member 95 is arranged in the groove portion 900, the inner peripheral wall of the intermediate member 95 is tightly attached to the outer peripheral wall of the inner extension portion 92 of the upper shell 90, the outer peripheral wall of the intermediate member 95 is tightly attached to the inner peripheral wall of the outer extension portion 93 of the upper shell 90, the inner peripheral wall of the upper shell 90 is tightly attached to the outer peripheral wall of the fixed core 50, and the outer peripheral wall of the upper shell 90 is tightly attached to the inner peripheral wall of the outer cylinder portion 21 of the shell 20.

[0297] Here, the outer peripheral wall of the inner extension portion 92 of the upper shell 90 is formed in a tapered shape so as to approach the axis of the inner extension portion 92 at a predetermined ratio as it goes from the injection hole 13 side of the inner extension portion 92 in the axial direction to the side opposite to the injection hole 13. The inner peripheral wall of the outer extension portion 93 of the upper shell 90 is formed in a tapered shape so as to move away from the axis of the outer extension portion 93 at a predetermined ratio as it goes from the injection hole 13 side of the outer extension portion 93 in the axial direction to the side opposite to the injection hole 13.

[0298] Next, a method of assembling the upper case 90 between the fixed core 50 and the case 20 will be described.

[0299] (Upper housing assembly process)

[0300] After the coil assembly process, the upper shell 90 is inserted between the fixed core 50 and the housing 20. Specifically, first, the upper shell 90 is inserted from the side of the fixed core 50 opposite to the nozzle hole 13, and the coil frame extension part 552 is located in the cutout part. Then, the upper shell 90 is inserted between the fixed core 50 and the housing 20. As a result, the upper shell 90 abuts against the step surface 205 and is restricted from moving toward the nozzle hole 13 side (see Fig.18 ).

[0301] Thereafter, the intermediate member 95 is inserted from the side of the fixed core 50 opposite to the injection hole 13 , and the coil bobbin extension portion 552 is positioned at the cutout portion, and then the intermediate member 95 is press-fitted into the groove portion 900 of the upper case 90 .

[0302] like Fig.18 As shown, when the intermediate member 95 is pressed into the groove portion 900, in a state before the intermediate member 95 is pressed into the groove portion 900, that is, in a state in which the inner peripheral wall of the intermediate member 95 and the outer peripheral wall of the inner extension portion 92 do not face each other in the radial direction, and in a state in which the outer peripheral wall of the intermediate member 95 and the inner peripheral wall of the outer extension portion 93 do not face each other in the radial direction, the inner peripheral wall of the inner extension portion 92 is formed in a tapered shape so as to be away from the axis at a predetermined ratio as it goes from the injection hole 13 side in the axial direction to the side opposite to the injection hole 13, and the side opposite to the injection hole 13 is separated from the outer peripheral wall of the fixed core 50. In addition, in this state, the outer peripheral wall of the outer extension portion 93 is formed in a tapered shape so as to be closer to the axis at a predetermined ratio as it goes from the injection hole 13 side in the axial direction to the side opposite to the injection hole 13, and the side opposite to the injection hole 13 is separated from the inner peripheral wall of the outer cylinder portion 21 of the housing 20.

[0303] In this state, the outer peripheral wall of the inner extension portion 92 is formed in a tapered shape so as to approach the axis at a predetermined ratio as it goes from the injection hole 13 side in the axial direction to the side opposite to the injection hole 13. In addition, the inner peripheral wall of the outer extension portion 93 is formed in a tapered shape so as to depart from the axis at a predetermined ratio as it goes from the injection hole 13 side in the axial direction to the side opposite to the injection hole 13.

[0304] In this state, when the intermediate member 95 is inserted into the groove 900 and moved toward the injection hole 13, the inner peripheral wall of the intermediate member 95 contacts and slides with the outer peripheral wall of the inner extension 92, and the outer peripheral wall of the intermediate member 95 contacts and slides with the inner peripheral wall of the outer extension 93. At this time, the inner extension 92 is deformed radially inwardly in such a manner that the inner diameter and the outer diameter are reduced. Therefore, the inner peripheral wall of the inner extension 92 abuts against and tightly adheres to the outer peripheral wall of the fixed core 50.

[0305] At this time, the outer extension portion 93 is deformed radially outward so that the inner diameter and the outer diameter are enlarged. Therefore, the outer peripheral wall of the outer extension portion 93 abuts against and closely adheres to the inner peripheral wall of the outer cylinder portion 21 of the housing 20 .

[0306] Thus, after the upper shell 90 and the intermediate member 95 are assembled, the inner peripheral wall of the intermediate member 95 is in close contact with the outer peripheral wall of the inner extension 92, the outer peripheral wall of the intermediate member 95 is in close contact with the inner peripheral wall of the outer extension 93, and the inner peripheral wall of the upper shell 90 is in close contact with the outer peripheral wall of the fixed core 50, and the outer peripheral wall of the upper shell 90 is in close contact with the inner peripheral wall of the outer cylinder portion 21 of the shell 20 (see Fig.17 ).

[0307] With the above structure, when the coil 55 is energized, an efficient magnetic path with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 90, the intermediate member 95, and the shell 20 (see Fig.17 ).

[0308] As described above, in this embodiment, the upper shell 90 has a bottom 91, an inner extension portion 92 formed in a manner extending axially from the inner edge of the bottom 91 to the bottom 91, and an outer extension portion 93 formed in a manner extending axially from the outer edge of the bottom 91 to the bottom 91.

[0309] In addition, the present embodiment further includes an intermediate member 95 provided between the inner extension portion 92 and the outer extension portion 93 .

[0310] Therefore, by appropriately setting the inner diameter of the inner extension portion 92 of the upper shell 90, the outer diameter of the outer extension portion 93, the outer diameter of the fixed core 50, the inner diameter of the shell 20, and the inner and outer diameters of the intermediate member 95 before assembling the upper shell 90, when assembling the upper shell 90 and the intermediate member 95, by inserting the upper shell 90 from the side opposite to the injection hole 13 relative to the coil 55 between the fixed core 50 and the shell 20, and inserting the intermediate member 95 between the inner extension portion 92 and the outer extension portion 93, the inner circumferential wall of the intermediate member 95 and the outer circumferential wall of the inner extension portion 92 can be axially slid, and the outer circumferential wall of the intermediate member 95 and the inner circumferential wall of the outer extension portion 93 can be axially slid, while the inner extension portion 92 can be deformed radially inwardly and the outer extension portion 93 can be deformed radially outwardly.

[0311] Therefore, after the upper shell 90 and the intermediate component 95 are assembled, the inner peripheral wall of the intermediate component 95 is tightly attached to the outer peripheral wall of the inner extension part 92, the outer peripheral wall of the intermediate component 95 is tightly attached to the inner peripheral wall of the outer extension part 93, the inner peripheral wall of the inner extension part 92 is tightly attached to the outer peripheral wall of the fixed core 50, and the outer peripheral wall of the outer extension part 93 is tightly attached to the inner peripheral wall of the shell 20.

[0312] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 90, the intermediate member 95 and the shell 20. Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. As a result, the power consumption of the fuel injection valve 1 can be reduced.

[0313] In the present embodiment, the intermediate member 95 is provided so as to bias the inner extending portion 92 radially inward of the bottom portion 91. Therefore, the inner peripheral wall of the inner extending portion 92 and the outer peripheral wall of the stationary core 50 can be brought into closer contact with each other.

[0314] In the present embodiment, the intermediate member 95 is provided so as to bias the outer extension portion 93 radially outward of the bottom portion 91. Therefore, the outer peripheral wall of the outer extension portion 93 and the inner peripheral wall of the housing 20 can be brought into closer contact with each other.

[0315] In the present embodiment, the intermediate member 95 can form a magnetic circuit together with the upper case 90. Therefore, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be reliably formed in the fixed core 50, the upper case 90, the intermediate member 95, and the case 20.

[0316] (Sixth embodiment)

[0317] Fig.19 1 shows a part of a fuel injection valve according to a sixth embodiment. The sixth embodiment is different from the fifth embodiment in the structure of an upper housing and the like.

[0318] This embodiment does not include the intermediate member 95 shown in the fifth embodiment.

[0319] like Fig.19 As shown, in this embodiment, when the upper shell 90 is arranged between the fixed core 50 and the outer tube portion 21 of the shell 20, the inner peripheral wall of the upper shell 90 on the side opposite to the nozzle hole 13 is tightly attached to the outer peripheral wall of the fixed core 50, and the outer peripheral wall of the upper shell 90 on the side opposite to the nozzle hole 13 is tightly attached to the inner peripheral wall of the outer tube portion 21 of the shell 20.

[0320] Here, the inner peripheral wall of the upper case 90 on the injection hole 13 side is separated from the outer peripheral wall of the fixed core 50 , and the outer peripheral wall of the upper case 90 on the injection hole 13 side is separated from the inner peripheral wall of the outer cylinder portion 21 of the case 20 .

[0321] In addition, on the injection hole 13 side relative to the bottom surface of the groove portion 900, that is, the end surface of the bottom 91 on the side opposite to the injection hole 13, the inner peripheral wall of the upper shell 90 is separated from the outer peripheral wall of the fixed core 50, and the outer peripheral wall of the upper shell 90 is separated from the inner peripheral wall of the outer tube portion 21 of the shell 20.

[0322] That is, from the end of the upper shell 90 on the opposite side of the nozzle hole 13 to the nozzle hole 13 side relative to the bottom surface of the groove 900, the inner circumferential wall of the upper shell 90 is tightly attached to the outer circumferential wall of the fixed core 50, and the outer circumferential wall of the upper shell 90 is tightly attached to the inner circumferential wall of the outer tube portion 21 of the shell 20.

[0323] Therefore, it is possible to ensure a magnetic path area between the inner peripheral wall of the upper case 90 and the outer peripheral wall of the fixed core 50 and a magnetic path area between the outer peripheral wall of the upper case 90 and the inner peripheral wall of the outer cylinder portion 21 of the case 20 .

[0324] Next, a method of assembling the upper case 90 between the fixed core 50 and the case 20 will be described.

[0325] (Upper housing assembly process)

[0326] After the coil assembly process, the upper shell 90 is inserted between the fixed core 50 and the housing 20. Specifically, the upper shell 90 is inserted from the side of the fixed core 50 opposite to the nozzle 13, and the coil frame extension part 552 is located in the cutout part, and the upper shell 90 is pressed between the fixed core 50 and the housing 20.

[0327] like Fig. 20 As shown, when the upper shell 90 is pressed into between the fixed core 50 and the shell 20, in the state before being pressed into, the inner peripheral wall of the upper shell 90 is formed into a tapered shape in a manner that approaches the axis at a predetermined ratio as it goes from the axial side of the injection hole 13 to the side opposite to the injection hole 13. In addition, in this state, the outer peripheral wall of the upper shell 90 is formed into a tapered shape in a manner that moves away from the axis at a predetermined ratio as it goes from the axial side of the injection hole 13 to the side opposite to the injection hole 13.

[0328] In this state, when the upper shell 90 is moved toward the injection hole 13, the inner peripheral wall of the upper shell 90 contacts and slides with the outer peripheral wall of the fixed core 50, and the outer peripheral wall of the upper shell 90 contacts and slides with the inner peripheral wall of the outer cylinder portion 21 of the shell 20. At this time, the inner extension portion 92 is deformed radially outward in such a manner that the inner diameter and the outer diameter are enlarged. Therefore, the inner peripheral wall of the inner extension portion 92 is in close contact with the outer peripheral wall of the fixed core 50.

[0329] At this time, the outer extension portion 93 is deformed radially inward so that the inner diameter and the outer diameter are reduced. Therefore, the outer peripheral wall of the outer extension portion 93 is in close contact with the inner peripheral wall of the outer cylinder portion 21 of the housing 20 .

[0330] Thus, after the upper housing 90 is assembled, the inner peripheral wall of the upper housing 90 is in close contact with the outer peripheral wall of the fixed core 50, and the outer peripheral wall of the upper housing 90 is in close contact with the inner peripheral wall of the outer cylinder portion 21 of the housing 20 (see Fig.19 , Fig. 20 ).

[0331] With the above structure, when the coil 55 is energized, an efficient magnetic path with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 90, and the shell 20 (see Fig.19 ).

[0332] As described above, in this embodiment, the upper shell 90 has a bottom 91, an inner extension portion 92 formed in a manner extending axially from the inner edge of the bottom 91 to the bottom 91, and an outer extension portion 93 formed in a manner extending axially from the outer edge of the bottom 91 to the bottom 91.

[0333] Therefore, by appropriately setting the inner diameter of the inner extension portion 92 of the upper shell 90, the outer diameter of the outer extension portion 93, the outer diameter of the fixed core 50 and the inner diameter of the shell 20 before assembling the upper shell 90, when assembling the upper shell 90, by inserting the upper shell 90 from the side opposite to the nozzle 13 relative to the coil 55 between the fixed core 50 and the shell 20, the inner circumferential wall of the inner extension portion 92 can be axially slid against the outer circumferential wall of the fixed core 50, and the outer circumferential wall of the outer extension portion 93 can be axially slid against the inner circumferential wall of the shell 20, while the inner extension portion 92 can be deformed radially outward and the outer extension portion 93 can be deformed radially inward.

[0334] Thus, after the upper housing 90 is assembled, the inner peripheral wall of the inner extension portion 92 is in close contact with the outer peripheral wall of the fixed core 50 , and the outer peripheral wall of the outer extension portion 93 is in close contact with the inner peripheral wall of the housing 20 .

[0335] Therefore, an efficient magnetic circuit with small magnetic gap and magnetic resistance can be formed in the fixed core 50, the upper shell 90 and the shell 20. Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. As a result, the power consumption of the fuel injection valve 1 can be reduced.

[0336] In the present embodiment, the upper case 90 is provided so that the outer peripheral wall of the end portion on the injection hole 13 side is separated from the inner peripheral wall of the case 20 and the inner peripheral wall of the end portion on the injection hole 13 side is separated from the outer peripheral wall of the fixed core 50 .

[0337] Therefore, it is possible to prevent the molten resin from entering between the inner peripheral wall of the upper case 90 and the outer peripheral wall of the fixed core 50 and between the outer peripheral wall of the upper case 90 and the inner peripheral wall of the housing 20 from the side opposite to the injection hole 13 with respect to the upper case 90 during the molding process. As a result, it is possible to prevent the inner peripheral wall of the upper case 90 from being separated from the outer peripheral wall of the fixed core 50, and it is possible to prevent the outer peripheral wall of the upper case 90 from being separated from the inner peripheral wall of the housing 20. Therefore, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be reliably formed in the fixed core 50, the upper case 90, and the housing 20.

[0338] (Seventh Implementation Method)

[0339] Fig.21 1 shows a part of a fuel injection valve according to a seventh embodiment. The structure of an upper housing of the seventh embodiment is different from that of the first embodiment.

[0340] In the present embodiment, the outer peripheral wall of the end portion in the circumferential direction of the main body 71 of the upper case 70 is spaced apart from the virtual tapered surface Stv1 by a predetermined distance d1.

[0341] Therefore, compared with the first embodiment, when the upper shell 70 is pressed into the inner side of the outer tube portion 21 of the shell 20 in the upper shell assembly process, the radial force acting from the outer peripheral wall (first tapered surface St1) of the circumferential end of the main body 71 of the upper shell 70 on the inner peripheral wall of the outer tube portion 21 of the shell 20 can be reduced. As a result, the assemblability of the upper shell 70 can be improved.

[0342] In addition, after the upper shell 70 is assembled, the radial force acting from the outer peripheral wall (first tapered surface St1) of the circumferential end of the main body 71 of the upper shell 70 to the inner peripheral wall (second tapered surface St2) of the outer cylinder portion 21 of the shell 20 can also be reduced. As a result, the stress generated in the portion of the inner peripheral wall of the outer cylinder portion 21 of the shell 20 that faces the outer peripheral wall of the circumferential end of the main body 71 of the upper shell 70 can be reduced.

[0343] (Eighth Implementation Method)

[0344] Fig. 22 1 shows a part of a fuel injection valve according to an eighth embodiment. The structure of the upper housing of the eighth embodiment is different from that of the first embodiment.

[0345] In this embodiment, the distance d2 between the bottom surface of the recessed portion 73 of the upper shell 70 and the inner peripheral wall (first cylindrical surface Sc1) of the main body 71 is smaller than the distance between the bottom surface of the recessed portion 73 and the inner peripheral wall (first cylindrical surface Sc1) of the main body 71 in the first embodiment (refer to Figure 3 ). Therefore, the main body 71 can be easily deformed in the radial direction at the recessed portion 73. Therefore, in particular, the circumferential end of the main body 71 of the upper housing 70 can be easily deformed in the radial direction.

[0346] Therefore, compared with the first embodiment, when the upper shell 70 is pressed into the inner side of the outer tube portion 21 of the shell 20 in the upper shell assembly process, the radial force acting on the inner wall of the outer tube portion 21 of the shell 20, especially from the outer wall (first tapered surface St1) of the circumferential end of the main body 71 of the upper shell 70, can be reduced. As a result, the assemblability of the upper shell 70 can be improved.

[0347] In addition, after the upper shell 70 is assembled, the radial force acting on the inner wall (second tapered surface St2) of the outer cylinder portion 21 of the shell 20, especially from the outer wall (first tapered surface St1) of the circumferential end of the main body 71 of the upper shell 70, can be reduced. As a result, the stress generated in the portion of the inner wall of the outer cylinder portion 21 of the shell 20 that faces the outer wall of the circumferential end of the main body 71 of the upper shell 70 can be reduced.

[0348] (Ninth Implementation Method)

[0349] Fig.23 1 shows a part of a fuel injection valve according to a ninth embodiment. The structure of the upper housing of the ninth embodiment is different from that of the first embodiment.

[0350] In this embodiment, the upper shell 70 further includes an inner recess 74. The inner recess 74 is formed in a manner recessed radially outward from the inner peripheral wall of the main body 71. Six inner recesses 74 are formed at equal intervals in the circumferential direction of the main body 71. The inner recess 74 is formed between two adjacent recesses 73 in the circumferential direction of the main body 71.

[0351] Here, the maximum value d3 of the distance between the bottom surface of the inner recess 74 and the outer peripheral wall (first tapered surface St1) of the main body 71 is smaller than the distance d4 between the bottom surface of the recess 73 and the inner peripheral wall (first cylindrical surface Sc1) of the main body 71. Therefore, the main body 71 can be easily deformed in the radial direction at the inner recess 74. Therefore, in particular, the circumferential end of the main body 71 of the upper shell 70 can be easily deformed in the radial direction.

[0352] Therefore, compared with the first embodiment, when the upper shell 70 is pressed into the inner side of the outer tube portion 21 of the shell 20 in the upper shell assembly process, the radial force acting on the inner wall of the outer tube portion 21 of the shell 20, especially from the outer wall (first tapered surface St1) of the circumferential end of the main body 71 of the upper shell 70, can be reduced. As a result, the assemblability of the upper shell 70 can be improved.

[0353] In addition, after the upper shell 70 is assembled, the radial force acting on the inner wall (second tapered surface St2) of the outer cylinder portion 21 of the shell 20, especially from the outer wall (first tapered surface St1) of the circumferential end of the main body 71 of the upper shell 70, can be reduced. As a result, the stress generated in the portion of the inner wall of the outer cylinder portion 21 of the shell 20 that faces the outer wall of the circumferential end of the main body 71 of the upper shell 70 can be reduced.

[0354] (10th embodiment)

[0355] Fig.24 , Fig.251 shows a part of a fuel injection valve according to a tenth embodiment. The structure of an upper housing of the tenth embodiment is different from that of the first embodiment.

[0356] In the present embodiment, the upper shell 70 further includes an axial recess 75. The axial recess 75 is formed in a circular manner from the end surface of the main body 71 of the upper shell 70 on the side opposite to the injection hole 13 in the axial direction. As a result, an arc-shaped wall portion 76 is formed radially outside the axial recess 75 of the main body 71, between two adjacent recesses 73 and at both ends of the main body 71 in the circumferential direction. Therefore, the wall portion 76 in the main body 71 can be easily deformed radially inward of the main body 71.

[0357] Therefore, compared with the first embodiment, when the upper shell 70 is pressed into the inner side of the outer tube portion 21 of the shell 20 in the upper shell assembly process, the radial force acting from the outer peripheral wall of the wall portion 76 of the upper shell 70 to the inner peripheral wall of the outer tube portion 21 of the shell 20 can be reduced. As a result, the assemblability of the upper shell 70 can be improved.

[0358] In addition, after the upper shell 70 is assembled, the radial force acting on the inner peripheral wall (second tapered surface St2) of the outer tube portion 21 of the shell 20, especially from the outer peripheral wall of the wall portion 76 of the upper shell 70, can also be reduced. As a result, the stress generated in the portion of the inner peripheral wall of the outer tube portion 21 of the shell 20 that faces the outer peripheral wall of the wall portion 76 of the upper shell 70 can be reduced.

[0359] (11th embodiment)

[0360] Fig.26 1 shows a part of a fuel injection valve according to an eleventh embodiment. The eleventh embodiment is different from the first embodiment in the structure of a housing and the like.

[0361] In the present embodiment, an annular stepped surface 205 is formed on the inner peripheral wall of the outer cylinder portion 21 of the housing 20. The upper housing 70 abuts against the stepped surface 205, and movement toward the injection hole 13 side is restricted.

[0362] Next, the “upper housing assembling step” in the method for manufacturing the fuel injection valve 1 according to the present embodiment will be described.

[0363] (Upper housing assembly process)

[0364] like Fig. 27As shown, in a state where the first conical surface St1 and the second conical surface St2 are not facing each other in the radial direction and a gap Sp1 is formed between the first cylindrical surface Sc1 and the outer peripheral wall of the fixed core 50, when the upper shell 70 is further moved toward the injection hole 13 side, the first conical surface St1 of the upper shell 70 and the second conical surface St2 of the shell 20 slide. At this time, the upper shell 70 is deformed radially inward in a manner that the inner diameter and the outer diameter are reduced. Therefore, the first cylindrical surface Sc1 of the upper shell 70 abuts and tightly adheres to the second cylindrical surface Sc2 of the fixed core 50. When the upper shell 70 is further moved toward the injection hole 13 side, the outer edge portion of the surface of the upper shell 70 on the injection hole 13 side abuts against the step surface 205. As a result, after the upper shell 70 is assembled, the first conical surface St1 and the second conical surface St2 are tightly adhered, and the first cylindrical surface Sc1 and the second cylindrical surface Sc2 are tightly adhered (refer to Fig. 27 ).

[0365] In this embodiment, similarly to the first embodiment, before the upper shell 70 is assembled to the inner side of the shell 20, the ratio of the diameter reduction of the first conical surface St1 of the upper shell 70, i.e., the diameter reduction rate, is slightly larger than the diameter reduction rate of the second conical surface St2 of the shell 20. That is, the inclination angle of the first conical surface St1 relative to the axis, i.e., the cone angle, is larger than the cone angle of the second conical surface St2. Therefore, when the upper shell 70 is pressed into the inner side of the shell 20 in the upper shell assembly process, the outer peripheral wall of the end of the upper shell 70 on the side opposite to the injection hole 13 first contacts the inner peripheral wall of the shell 20. Thus, it is possible to suppress the cracking of the upper shell 70 when it is pressed in, and to reduce the pressing load.

[0366] When the first conical surface St1 and the second conical surface St2 slide while the upper shell 70 moves toward the nozzle hole 13, the surface pressure between the outer wall (St1) of the end of the upper shell 70 on the side opposite to the nozzle hole 13 and the inner wall (St2) of the shell 20 is greater than the surface pressure between the first cylindrical surface Sc1 and the second cylindrical surface Sc2. Therefore, when the upper shell 70 moves toward the nozzle hole 13, at least one of the outer wall of the end of the upper shell 70 on the side opposite to the nozzle hole 13 and the inner wall of the shell 20 is deformed or crushed. As a result, the outer wall of the upper shell 70 is in close contact with the inner wall of the shell 20. Therefore, in the fixed core 50, the upper shell 70 and the shell 20, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be reliably formed.

[0367] In addition, in the present embodiment, at the end of the upper shell assembly process, the outer edge of the surface of the upper shell 70 on the side of the nozzle hole 13 abuts against the step surface 205. As a result, the upper shell 70 is restricted from moving toward the nozzle hole 13. Therefore, the deviation of the position of the upper shell 70 relative to the shell 20 is suppressed, and the distance between the upper shell 70 and the coil frame 551 can be fixed. By fixing the distance between the upper shell 70 and the coil frame 551, the coil frame protrusion 550, which is a protrusion on the upper shell 70 side of the coil frame 551, can be reliably melted by using the high-temperature resin that flows between the upper shell 70 and the coil frame 551 during the molding process. Therefore, the sealing between the upper shell 70 and the coil 55 can be improved.

[0368] The above structure can reduce the surface pressure between the upper shell 70 and the shell 20 when the upper shell 70 is pressed in. As a result, the assembly performance can be improved. In addition, by reducing the surface pressure between the upper shell 70 and the shell 20, the cracking can be further effectively suppressed. Therefore, foreign matter can be prevented from falling on the coil 55 side and local short circuit (rare short) can be suppressed.

[0369] (12th embodiment)

[0370] A fuel injection valve according to a twelfth embodiment will be described. The twelfth embodiment is different from the eleventh embodiment in the structure of the upper housing and the housing.

[0371] In the present embodiment, the base material hardness of the housing 20 is lower than the base material hardness of the upper housing 70. In addition, the portion of the inner peripheral wall of the outer cylinder 21 of the housing 20 corresponding to the second tapered surface St2 has a surface hardness higher than the base material hardness by, for example, shot peening, increasing cutting resistance, surface treatment using a squeeze roller, etc. In addition, the surface hardness of the portion of the inner peripheral wall of the outer cylinder 21 corresponding to the second tapered surface St2 is the same as the surface hardness of the portion of the outer peripheral wall of the upper housing 70 corresponding to the first tapered surface St1.

[0372] With the above structure, when the upper shell 70 is pressed into the inner side of the shell 20 during the upper shell assembly process, the inner peripheral wall of the shell 20 is particularly pressed by the outer peripheral wall of the end of the upper shell 70 opposite to the nozzle hole 13, and the inside of the shell 20, i.e., the base material, is deformed in a compressed manner. As a result, the outer peripheral wall of the upper shell 70 can be made to fit more closely to the inner peripheral wall of the shell 20.

[0373] In addition, the above structure can reduce the surface pressure between the upper shell 70 and the shell 20 when the upper shell 70 is pressed in. As a result, the assembly performance can be improved. In addition, by reducing the surface pressure between the upper shell 70 and the shell 20, the cracking can be further effectively suppressed. Therefore, it is possible to suppress foreign matter from falling on the coil 55 side and local short circuit.

[0374] (13th embodiment)

[0375] based on Fig.28 A fuel injection valve according to a thirteenth embodiment will be described. The thirteenth embodiment is different from the eleventh embodiment in the structure of the upper housing and the like.

[0376] In the present embodiment, the outer peripheral wall (first tapered surface St1) of the upper housing 70 is formed into a curved surface in such a manner that the central portion in the axial direction of the upper housing 70 protrudes radially outward. The outer peripheral wall of the upper housing 70 is formed into an arc shape in a cross section of a plane including the axis of the upper housing 70 (see Fig.28 ).

[0377] The first tapered surface St1 is tapered so as to approach the axis from the center C1 toward the injection hole 13. The reduction rate of the first tapered surface St1 increases from the center C1 toward the injection hole 13.

[0378] In addition, the portion of the first tapered surface St1 on the side opposite to the injection hole 13 from the center C1 in the axial direction of the upper shell 70 is formed in a tapered shape so as to approach the axis as it goes from the center C1 to the side opposite to the injection hole 13. Here, the diameter reduction rate of the first tapered surface St1 changes so as to increase as it goes from the center C1 to the side opposite to the injection hole 13.

[0379] The above structure can reduce the surface pressure between the upper shell 70 and the shell 20 when the upper shell 70 is pressed in. As a result, the assembly performance can be improved. In addition, by reducing the surface pressure between the upper shell 70 and the shell 20, the cracking can be further effectively suppressed. Therefore, foreign matter can be suppressed from falling on the coil 55 side and local short circuit.

[0380] (14th embodiment)

[0381] based on Fig.29 A fuel injection valve according to a fourteenth embodiment will be described. The fourteenth embodiment is different from the eleventh embodiment in the structure of an upper housing and the like.

[0382] In the present embodiment, the upper shell 70 has an outer peripheral recess 77. The outer peripheral recess 77 is formed in a manner recessed radially inward from the outer peripheral wall of the main body 71 of the upper shell 70. The outer peripheral recess 77 is formed from the end of the main body 71 on the side of the injection hole 13 to the axial center of the main body 71. As a result, the axial length of the first conical surface St1 of the present embodiment is smaller than the axial length of the first conical surface St1 of the 11th embodiment. Therefore, the area of ​​the contact portion of the first conical surface St1 and the second conical surface St2, that is, the contact area, is also smaller than that of the 11th embodiment.

[0383] The above structure can reduce the length of the upper shell 70 and the housing 20 when the upper shell 70 is pressed in, and can reduce the amount of movement of the sliding part. As a result, the assembly performance can be improved. In addition, by reducing the amount of movement of the sliding part of the upper shell 70 and the housing 20, the cracking can be further effectively suppressed. Therefore, it is possible to suppress foreign matter from falling on the coil 55 side and local short circuit.

[0384] (15th embodiment)

[0385] based on Fig.30 A fuel injection valve according to a fifteenth embodiment will be described. The fifteenth embodiment is different from the eleventh embodiment in the structure of an upper housing and the like.

[0386] In the present embodiment, in the second conical surface St2 of the housing 20, the diameter reduction rates on the injection hole 13 side and the side opposite to the injection hole 13 relative to the specific portion in the axial direction, that is, the specific portion SL1, are different. The diameter reduction rate of the portion of the second conical surface St2 on the injection hole 13 side relative to the specific portion SL1 is greater than the diameter reduction rate of the portion of the second conical surface St2 on the side opposite to the injection hole 13 relative to the specific portion SL1.

[0387] The specific part SL1 is set closer to the injection hole 13 than the axial center C2 of the second tapered surface St2. The second tapered surface St2 is formed in a tapered shape close to a cylindrical shape on the opposite side of the specific part SL1 from the injection hole 13.

[0388] The corner formed by the end surface of the upper case 70 on the injection hole 13 side and the outer peripheral wall is chamfered into a curved surface shape.

[0389] In the present embodiment, when the upper shell 70 is pressed into the inner side of the shell 20 in the upper shell assembly process, when the outer peripheral wall (first conical surface St1) of the upper shell 70 slides with the portion of the second conical surface St2 on the side opposite to the injection hole 13 relative to the specific portion SL1, the upper shell 70 is hardly deformed radially inward. That is, at this time, the upper shell 70 is temporarily pressed into the shell 20.

[0390] On the other hand, when the outer peripheral wall (first conical surface St1) of the upper shell 70 slides with the portion of the second conical surface St2 on the injection hole 13 side relative to the specific portion SL1, the upper shell 70 is deformed radially inward in such a manner that the inner diameter and the outer diameter are reduced. That is, at this time, the upper shell 70 is officially pressed into the shell 20.

[0391] The above structure can reduce the length of the portion where the surface pressure between the upper shell 70 and the shell 20 increases when the upper shell 70 is pressed in (the side of the nozzle 13 relative to the specific portion SL1), and reduce the amount of movement of the sliding portion when a large surface pressure is applied. Thus, assemblability can be improved. In addition, by reducing the amount of movement of the sliding portion between the upper shell 70 and the shell 20 when a large surface pressure is applied, extrusion and cracking can be further and more efficiently suppressed. Therefore, foreign matter can be prevented from falling onto the coil 55 side and local short circuits can be suppressed.

[0392] (16th Implementation Method)

[0393] A fuel injection valve according to a sixteenth embodiment will be described. The sixteenth embodiment is different from the eleventh embodiment in the structure between the upper housing and the housing.

[0394] In this embodiment, when the upper shell 70 is pressed into the inner side of the shell 20 during the upper shell assembly process, lubricating oil is applied to at least one of the outer wall (first conical surface St1) of the upper shell 70 or the inner wall (second conical surface St2) of the outer tube portion 21 of the shell 20.

[0395] The above structure can reduce the friction coefficient between the upper shell 70 and the shell 20 when the upper shell 70 is pressed in. As a result, the assembly performance can be improved. In addition, by reducing the friction coefficient between the upper shell 70 and the shell 20, the cracking can be further effectively suppressed. Therefore, it is possible to suppress foreign matter from falling on the coil 55 side and local short circuit.

[0396] (17th Implementation Method)

[0397] A fuel injection valve according to a seventeenth embodiment will be described. The seventeenth embodiment is different from the sixteenth embodiment in the structure of the upper housing and the housing.

[0398] When the surface roughness of the outer wall (first conical surface St1) of the upper shell 70 or the inner wall (second conical surface St2) of the outer tube portion 21 of the shell 20 is less than a specified value, the friction coefficient between the upper shell 70 and the shell 20 when the upper shell 70 is pressed in may increase.

[0399] Therefore, in this embodiment, the surface roughness of the outer wall (first conical surface St1) of the upper shell 70 or the inner wall (second conical surface St2) of the outer tube portion 21 of the shell 20 is set to be greater than a specified value so that the friction coefficient between the upper shell 70 and the shell 20 is less than a specified value.

[0400] The above structure can reduce the friction coefficient between the upper shell 70 and the shell 20 when the upper shell 70 is pressed in. In addition, by setting the surface roughness of the outer wall (first conical surface St1) of the upper shell 70 or the inner wall (second conical surface St2) of the outer cylinder 21 of the shell 20 to a predetermined value or more, lubricating oil can be retained on the first conical surface St1 and the second conical surface St2 having fine concave and convex surfaces. Thus, assemblability can be improved. In addition, by reducing the friction coefficient between the upper shell 70 and the shell 20, extrusion cracking can be further and more efficiently suppressed. Therefore, foreign matter can be prevented from falling on the coil 55 side and local short circuit.

[0401] (Eighteenth Implementation Method)

[0402] A fuel injection valve according to an eighteenth embodiment will be described. The eighteenth embodiment is different from the eleventh embodiment in the upper casing assembly process.

[0403] In this embodiment, when the upper shell 70 is pressed into the inner side of the shell 20 in the upper shell assembly process, the upper shell 70 is pressed into the shell 20 at a speed greater than a degree that does not hinder the movement of the upper shell 70 due to static friction and less than a speed that does not cause the outer peripheral wall of the upper shell 70 and the inner peripheral wall of the shell 20 to melt.

[0404] As described above, by optimizing the speed when pressing into the upper housing 70, burning can be suppressed and the assembly performance can be improved. In addition, by optimizing the speed when pressing into the upper housing 70, cracking can be further effectively suppressed. Therefore, it is possible to suppress foreign matter from falling onto the coil 55 side and local short circuit.

[0405] (19th Implementation Method)

[0406] based on Fig.31 A fuel injection valve according to a nineteenth embodiment will be described. The nineteenth embodiment is different from the eleventh embodiment in the structure of an upper housing and the like.

[0407] In this embodiment, the upper case 70 has a punching recess 78. The punching recess 78 is formed in a manner recessed toward the injection hole 13 side at an outer edge of a surface of the main body 71 of the upper case 70 on the side opposite to the injection hole 13.

[0408] In the present embodiment, in the upper shell assembly process, first, the upper shell 70 without the punching recess 78 is pressed into the shell 20 until it abuts against the step surface 205. At this time, the surface pressure between the outer peripheral wall (first tapered surface St1) of the upper shell 70 and the inner peripheral wall (second tapered surface St2) of the shell 20 is set to be smaller than that in the eleventh embodiment.

[0409] After the upper shell 70 is in contact with the step surface 205, the jig is pressed against the outer edge of the surface of the main body 71 of the upper shell 70 on the side opposite to the injection hole 13 to form the punching recess 78. As a result, the outer peripheral wall of the end of the upper shell 70 on the side opposite to the injection hole 13 is deformed radially outward. As a result, the outer peripheral wall of the upper shell 70 is in close contact with the inner peripheral wall of the housing 20. Therefore, in the fixed core 50, the upper shell 70 and the housing 20, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be reliably formed.

[0410] As described above, by reducing the surface pressure between the upper shell 70 and the housing 20 when the upper shell 70 is pressed in, the assembly performance can be improved. In addition, by reducing the surface pressure between the upper shell 70 and the housing 20 when the upper shell 70 is pressed in, the cracking can be further effectively suppressed. Therefore, it is possible to suppress foreign matter from falling on the coil 55 side and local short circuit.

[0411] (1st reference method)

[0412] Fig.32 2 shows a part of a fuel injection valve according to a first reference embodiment. The first reference embodiment is different from the second comparative embodiment in the structure of the fixed core and the like.

[0413] In this reference embodiment, the stationary core 50 has a core peripheral recess 506. The core peripheral recess 506 is formed in an annular shape in a manner recessed radially inward from the outer peripheral wall of the stationary core 50. The core peripheral recess 506 is formed on the side opposite to the injection hole 13 with respect to the upper shell 70 in the axial direction of the stationary core 50.

[0414] The magnetic material ring 79 is arranged so that the inner edge is embedded in the core outer peripheral recess 506. Here, the inner edge of the magnetic material ring 79 is in close contact with the core outer peripheral recess 506. In addition, the end surface of the magnetic material ring 79 on the injection hole 13 side is in close contact with the end surface of the upper shell 70 on the side opposite to the injection hole 13. In addition, the magnetic material ring 79 is restricted from moving in the axial direction by engaging with the core outer peripheral recess 506.

[0415] Before assembly, the inner diameter of the magnetic material ring 79 is set to be smaller than the outer diameter D1 of the fixed core 50 and the outer diameter D2 of the cylindrical bottom surface of the core outer peripheral recess 506. Therefore, during assembly, the magnetic material ring 79 is pressed into the fixed core 50 with the inner peripheral wall expanded radially outward, and is embedded in the core outer peripheral recess 506 in a state of being pushed against the upper shell 70.

[0416] In the second comparative embodiment, there is a possibility that springback occurs when the magnetic material ring 79 is pressed in. Therefore, after the magnetic material ring 79 is assembled, there is a possibility that a gap as a magnetic gap is formed between the end surface of the upper shell 70 on the side of the magnetic material ring 79 and the end surface of the upper shell 70 on the side of the magnetic material ring 79 (see Fig.14 ).

[0417] On the other hand, in the present reference method, the axial movement of the magnetic material ring 79 is restricted by engagement with the core outer peripheral recess 506. Therefore, even if rebound occurs when the magnetic material ring 79 is pressed in, a gap serving as a magnetic gap can be prevented from being formed between the end face of the magnetic material ring 79 on the upper shell 70 and the end face of the magnetic material ring 79 on the upper shell 70.

[0418] Therefore, when the coil 55 is energized, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed in the fixed core 50, the magnetic material ring 79, the upper shell 70 and the shell 20 (see Fig.32 ). Therefore, an attractive force can be efficiently generated for the current input to the coil 55, and the energy required for driving the fuel injection valve 1 can be reduced. Thus, the power consumption of the fuel injection valve 1 can be reduced.

[0419] (Second reference method)

[0420] Fig.33 1 shows a part of a fuel injection valve according to a second reference embodiment. The second reference embodiment is different from the first reference embodiment in the structure of the magnetic material ring and the fixed core.

[0421] In this reference embodiment, an annular protrusion 791 is formed on the magnetic material ring 79. The annular protrusion 791 is formed in a manner protruding radially inward from the inner peripheral wall of the magnetic material ring 79. When viewed from the axial direction of the magnetic material ring 79, the annular protrusion 791 is formed in a substantially C-shape along the inner peripheral wall of the magnetic material ring 79. The annular protrusion 791 is formed at the center in the axial direction of the inner peripheral wall of the magnetic material ring 79. The wall surface forming the annular protrusion 791 is formed in a circular arc shape in a cross section of a plane including the axis of the magnetic material ring 79.

[0422] The stationary core 50 further includes a core recess 507. The core recess 507 is formed in an annular shape in a manner recessed radially inward from the cylindrical bottom surface of the core outer peripheral recess 506. The core recess 507 is formed in a manner corresponding to the shape of the annular protrusion 791 so that the wall surface forming the core recess 507 is in an arc shape in a cross section of a plane including the axis of the stationary core 50.

[0423] The magnetic material ring 79 is provided so that the inner edge is embedded in the core outer peripheral recess 506 and the annular protrusion 791 is embedded in the core recess 507. Here, the inner edge of the magnetic material ring 79 is in close contact with the core outer peripheral recess 506, and the annular protrusion 791 is in close contact with the core recess 507. In addition, the end surface of the magnetic material ring 79 on the injection hole 13 side is in close contact with the end surface of the upper shell 70 on the side opposite to the injection hole 13. In addition, the magnetic material ring 79 is restricted from moving in the axial direction by the engagement with the core outer peripheral recess 506 and the engagement of the annular protrusion 791 with the core recess 507.

[0424] By the above structure, in this reference mode, as in the first reference mode, it is possible to suppress the gap as a magnetic gap formed between the upper housing 70 and the magnetic material ring 79 after the magnetic material ring 79 is assembled. Therefore, when the coil 55 is energized, an efficient magnetic circuit with a small magnetic gap and magnetic resistance can be formed. Therefore, the energy required for driving the fuel injection valve 1 can be reduced, and the power consumption of the fuel injection valve 1 can be reduced.

[0425] (Reference 3)

[0426] Fig.34 1 shows a part of a fuel injection valve according to a third reference embodiment. The third reference embodiment is different from the second reference embodiment in the structure of the magnetic material ring and the fixed core.

[0427] In the present reference embodiment, the wall surface forming the annular protrusion 791 is formed to have a shape corresponding to three sides of the sides constituting the rectangle in a cross section of a plane including the axis of the magnetic material ring 79 .

[0428] The core recess 507 is formed to correspond to the shape of the annular protrusion 791 so that the wall surface forming the core recess 507 has a shape corresponding to three sides of the sides constituting the rectangle in a cross section of a plane including the axis of the fixed core 50 .

[0429] With the above-described structure, in the present reference embodiment, as in the second reference embodiment, it is possible to suppress the gap as a magnetic gap from being formed between the upper housing 70 and the magnetic ring 79 after the magnetic ring 79 is assembled.

[0430] (Reference 4)

[0431] Fig.35 1 shows a part of a fuel injection valve according to a fourth reference embodiment. The structure of the fixed core of the fourth reference embodiment is different from that of the second reference embodiment.

[0432] In the present reference embodiment, the fixed core 50 does not have the core outer peripheral recessed portion 506 shown in the first reference embodiment.

[0433] The magnetic material ring 79 is provided so that the annular protrusion 791 is embedded in the core recess 507. Here, the inner peripheral wall of the magnetic material ring 79 is in close contact with the outer peripheral wall of the fixed core 50, and the annular protrusion 791 is in close contact with the core recess 507. In addition, the end surface of the magnetic material ring 79 on the side of the injection hole 13 is in close contact with the end surface of the upper shell 70 on the side opposite to the injection hole 13. In addition, the magnetic material ring 79 is restricted from moving in the axial direction by the engagement of the annular protrusion 791 with the core recess 507.

[0434] With the above-described structure, in the present reference embodiment, as in the second reference embodiment, it is possible to suppress the gap as a magnetic gap from being formed between the upper housing 70 and the magnetic ring 79 after the magnetic ring 79 is assembled.

[0435] (Implementation 20)

[0436] Fig.36 2 shows a fuel injection valve according to a twentieth embodiment. The twentieth embodiment is different from the first embodiment in that a plurality of components are added.

[0437] The fuel injection valve 1 of the present embodiment is disposed in the cover hole portion 8 formed at the center of the upper side of the combustion chamber 7 of the cylinder head 6, and injects fuel from the side in the vertical direction of the combustion chamber 7 to the inside of the combustion chamber 7. In this way, the present embodiment is applied to a so-called center injection type internal combustion engine. In the case of a center injection type internal combustion engine, components such as a spark plug are arranged around the fuel injection valve, so the distance from the cup 9 of the fuel pipe connected to the fuel inlet 101 of the fuel injection valve 1 to the combustion chamber 7 is relatively large. Therefore, the length from the fuel inlet 101 of the fuel injection valve 1 of the present embodiment to the injection hole 13 is relatively large.

[0438] like Fig.36 As shown, the present embodiment further includes a pipe inlet 41, a lower O-ring 5, a flange inlet 18, a terminal 555, a terminal molded portion 58, an outer peripheral molded portion 59, a retainer 17, and the like.

[0439] The pipe inlet 41 is formed in a cylindrical shape by metal such as stainless steel, for example. The pipe inlet 41 is formed so that the inner diameter and the outer diameter are different in the axial direction. Therefore, a plurality of annular step surfaces are formed inside and outside the pipe inlet 41.

[0440] A fuel inlet 101 is formed at one end of the tube inlet 41 and is connected to the cup 9 of the fuel pipe. The fuel inlet 101 communicates with the injection hole 13 through a fuel flow path 100. The fuel flowing from the fuel inlet 101 can flow to the injection hole 13 through the fuel flow path 100.

[0441] The other end of the pipe inlet 41 is pressed into the end of the fixed core 50 on the side opposite to the injection hole 13. The lower O-ring 5 is formed into a ring shape by an elastic member such as rubber. The lower O-ring 5 is arranged between the inner peripheral wall of the other end of the pipe inlet 41 and the outer peripheral wall of the end of the fixed core 50 on the side opposite to the injection hole 13 in a radially compressed state. Thus, the other end of the pipe inlet 41 and the end of the fixed core 50 on the side opposite to the injection hole 13 are maintained liquid-tight.

[0442] The flange inlet 18 is formed in an annular shape by metal such as stainless steel, for example. The flange inlet 18 is press-fitted into a portion of the pipe inlet 41 on the opposite side to the fixed core 50 .

[0443] The terminal 555 is formed of a conductor such as metal. The terminal molded portion 58 is formed integrally with the connector portion 57 by resin, and molds the terminal 555 together with the connector portion 57. Here, one end of the terminal 555 is exposed to the space inside the connector portion 57.

[0444] This embodiment includes a conductive portion 554 instead of the terminal 553. The conductive portion 554 is formed of a conductor such as metal, one end of which is connected to the coil 55 and is covered by the bobbin extension portion 552 and the mold portion 56. Here, the other end of the conductive portion 554 is exposed from the mold portion 56.

[0445] The terminal molded portion 58 is provided along the outer wall of the tube inlet 41 in the axial direction of the tube inlet 41 at the radially outer side of the tube inlet 41. The other end of the terminal 555 and the other end of the conductive portion 554 are electrically connected by welding.

[0446] The outer peripheral molded portion 59 is formed of resin, and covers a portion of the outer peripheral wall of the molded portion 56 , a portion of the outer peripheral wall of the tube inlet 41 , a portion of the flange inlet 18 , the terminal molded portion 58 , and a portion of the connector portion 57 .

[0447] The retainer 17 is formed of metal, for example, and is provided at the end portion of the outer peripheral mold portion 59 on the opposite side to the nozzle hole 13 .

[0448] like Figure 37 to Figure 39 As shown, a plurality of molded recesses 593 are formed on the outer wall of the outer peripheral molded portion 59. The molded recesses 593 are formed in a manner recessed from the outer wall of the outer peripheral molded portion 59 and extending along the terminal molded portion 58 on the inner side of the outer peripheral molded portion 59. The molded recesses 593 can make the overall flow of the resin when forming the outer peripheral molded portion 59 uniform, and can maintain the wall thickness of each portion.

[0449] The retainer 17 is formed of metal such as stainless steel, for example. The retainer 17 includes a spring portion 171 , a fitting portion 172 , a contact portion 173 , and a retainer holding portion 174 .

[0450] The spring portion 171 is formed by forming a plurality of cutouts extending in the longitudinal direction in a rectangular plate-shaped member, and bending the member in the longitudinal direction to form a substantially C-shape when viewed in the axial direction. Thus, the spring portion 171 can be elastically deformed in the axial direction.

[0451] The fitting portion 172 is formed to extend in the axial direction from the circumferential center of the spring portion 171. The fitting portion 172 can be fitted into other members such as a fuel pipe. Thus, the retainer 17 can be positioned in the circumferential direction (rotational direction).

[0452] The contact portion 173 is formed at the end of the spring portion 171 on the opposite side from the embedding portion 172. The contact portion 173 can contact the flange inlet 18 exposed from the outer peripheral mold portion 59 (see Fig.36 ).

[0453] The retainer holding portions 174 are formed at both ends of the spring portion 171 in the circumferential direction. The retainer holding portions 174 can be engaged with the outer wall of the outer peripheral mold portion 59.

[0454] The retainer 17 is provided so that the contact portion 173 contacts the flange inlet 18 and the retainer holding portion 174 engages with the outer wall of the outer peripheral mold portion 59 .

[0455] When the fuel injection valve 1 is set in the cover hole 8 of the cylinder head 6, the circumferential (rotational) positioning of the fuel injection valve 1 can be performed by embedding the embedding portion 172 in other components such as the fuel pipe. In addition, when the fuel injection valve 1 is set in the cover hole 8, the spring portion 171 of the retainer 17 is compressed in the axial direction. Therefore, the force of the spring portion 171 acts on the flange inlet 18, and the fuel injection valve 1 is urged toward the combustion chamber 7 side. As a result, it is possible to suppress the fuel injection valve 1 from moving in the direction of leaving the cover hole 8 due to the combustion pressure generated in the combustion chamber 7.

[0456] like Fig.40 As shown in FIG. 1 , a rib 591 is formed at a portion of the outer peripheral molded portion 59 adjacent to the connector portion 57. Thus, the portion of the outer peripheral molded portion 59 adjacent to the connector portion 57 can be reinforced. Therefore, even if external force acts on the outer peripheral molded portion 59 from a harness connected to the connector portion 57, a hand of a person holding the vicinity of the connector portion 57, or the like, the outer peripheral molded portion 59 can be prevented from being damaged.

[0457] A thinned portion 592 is formed near the flange inlet 18 of the outer peripheral mold portion 59. Thus, the formation of a void inside the outer peripheral mold portion 59 can be suppressed.

[0458] like Fig.41 As shown, the terminal molded portion 58 has a retaining portion 581. Two retaining portions 581 are formed in the longitudinal direction of the terminal molded portion 58. The terminal molded portion 58 is provided so that the outer peripheral wall of the tube inlet 41 is sandwiched by the retaining portion 581 before the tube inlet 41 is covered by the outer peripheral molded portion 59 by resin molding. Here, the terminal molded portion 58 is provided so that the end of the conductive portion 554 abuts against the end of the terminal 555.

[0459] like Fig.42As shown, a punched hole portion 556 is formed by punching at the end of the terminal 555. The end of the conductive portion 554 and the end of the terminal 555 are welded by projection welding, for example. Specifically, a large current flows through the punched hole portion 556 of the terminal 555, and the punched hole portion 556 and the conductive portion 554 are melted and welded by heat. By projection welding, the deviation of welding resistance can be suppressed, and the welding can be stabilized.

[0460] like Fig.41 , Fig.43 As shown, a molded hole 582 is formed in the terminal molded portion 58. The molded hole 582 is formed to hold the terminal 555 when the terminal molded portion 58 is molded with resin. Therefore, after the terminal 555 is covered with the terminal molded portion 58, the terminal 555 is exposed through the molded hole 582 so as to be visible. Four molded holes 582 are formed in the longitudinal direction of the terminal molded portion 58.

[0461] The terminal mold 58 is formed with welding protrusions 583 and 584. A plurality of welding protrusions 583 are formed in the longitudinal direction of the terminal mold 58 so as to sandwich each mold hole 582. The welding protrusion 583 is formed in a ring shape around the terminal mold 58 so as to protrude from the outer wall of the terminal mold 58.

[0462] The welding protrusion 584 is formed in an annular shape around the terminal mold portion 58 so as to protrude from the outer wall of the end portion of the terminal mold portion 58 on the opposite side to the connector portion 57 .

[0463] A welding protrusion 561 is formed at the end of the molded portion 56 on the terminal molded portion 58 side (see Fig.42 ). The welded protrusion 561 is formed around the exposed conductive portion 554 so as to protrude from the outer wall of the mold portion 56 .

[0464] When the outer peripheral mold portion 59 is formed, the welding protrusion 583 is melted by the heat of the molten resin and becomes integrated with a part of the outer peripheral mold portion 59. Thus, the periphery of the mold hole portion 582 can be sealed, and it is possible to suppress water or the like from the outside from adhering to the terminal 555 through the mold hole portion 582. Thus, corrosion of the terminal 555 can be suppressed.

[0465] Furthermore, when the outer peripheral mold portion 59 is formed, the welding protrusion 584 and the welding protrusion 561 are melted by the heat of the molten resin and are integrated with a part of the outer peripheral mold portion 59. Thus, the periphery of the welded portion between the terminal 555 and the conductive portion 554 can be sealed, and it is possible to suppress the adhesion of water and the like from the outside to the welded portion. Thus, it is possible to suppress the corrosion of the welded portion.

[0466] like Fig.36As shown, when forming the outer peripheral molded portion 59, the molten resin is flowed into the mold from the gates G1 to G4. The gates G1 and G2 are provided at locations corresponding to the terminal molded portion 58 in the circumferential direction of the outer peripheral molded portion 59. The gates G1 and G2 are provided at positions separated by a predetermined distance in the longitudinal direction of the outer peripheral molded portion 59.

[0467] The gate G3 is provided on the opposite side to the gate G1 with respect to the axis of the pipe inlet 41. The gate G4 is provided on the opposite side to the gate G2 with respect to the axis of the pipe inlet 41.

[0468] By setting the positions of the gates G1 to G4 as described above, a welded portion of the outer peripheral mold 59 can be formed between the gates G1 and G3 and between the gates G2 and G4. This can prevent the welded portion of the outer peripheral mold 59 from being formed near the welded protrusions 583 and 584 of the terminal mold 58. Therefore, the sealing performance by the welded protrusions 583 and 584 can be ensured.

[0469] like Fig.36 As shown, an upper O-ring 3 , a spacer 4 , and a ring stopper 16 are provided at the end of the pipe inlet 41 on the fuel inlet 101 side.

[0470] The end of the pipe inlet 41 on the fuel inlet 101 side is formed with a pipe large diameter step surface 411, a pipe small diameter step surface 412, and a stopper locking portion 413. The pipe large diameter step surface 411 is formed in an annular flat surface shape on the outer peripheral wall of the pipe inlet 41 so as to be substantially perpendicular to the axis of the pipe inlet 41.

[0471] The tube small diameter step surface 412 is formed in a flat annular shape on the fuel inlet 101 side of the outer peripheral wall of the tube inlet 41 relative to the tube large diameter step surface 411 so as to be substantially perpendicular to the axis of the tube inlet 41. The inner diameter and outer diameter of the tube small diameter step surface 412 are smaller than the inner diameter of the tube large diameter step surface 411.

[0472] The stopper locking portion 413 is formed in an annular shape so as to protrude radially outward from the outer peripheral wall of the end portion of the pipe inlet 41 on the fuel inlet 101 side.

[0473] The spacer 4 is formed into an annular shape by a metal such as stainless steel, and is arranged to abut against the pipe large diameter step surface 411. The upper O-ring 3 is formed into an annular shape by an elastic member such as rubber, and is arranged to abut against the surface of the spacer 4 on the side opposite to the pipe large diameter step surface 411. The ring stopper 16 is arranged between the pipe small diameter step surface 412 and the stopper locking portion 413. The outer diameter of the stopper locking portion 413 is larger than the inner diameter of the ring stopper 16. As a result, the stopper locking portion 413 locks the ring stopper 16, and the ring stopper 16 is prevented from falling off from the pipe inlet 41.

[0474] The outer diameter of the ring stopper 16 is larger than the inner diameter of the upper O-ring 3 . Thus, the ring stopper 16 can suppress the upper O-ring 3 from falling off from the pipe inlet 41 .

[0475] When the cup 9 of the fuel pipe is connected to the end of the pipe inlet 41 on the fuel inlet 101 side, the upper O-ring 3 is compressed in the radial direction between the inner peripheral wall of the cup 9 and the outer peripheral wall of the pipe inlet 41. Thus, the cup 9 and the pipe inlet 41 are kept liquid-tight.

[0476] The inner diameter of the cup 9 is larger than the inner diameter of the end of the tube inlet 41 on the fixed core 50 side. Therefore, when the inside of the cup 9 and the fuel flow path 100 are filled with fuel, the pressure receiving area of ​​the upper O-ring 3 is larger than the pressure receiving area of ​​the lower O-ring 5. As a result, the fuel pressure acting on the combustion chamber 7 side relative to the tube inlet 41 is larger than the fuel pressure acting on the cup 9 side relative to the tube inlet 41. Therefore, even if the inside of the cup 9 and the fuel flow path 100 are filled with high-pressure fuel, the separation of the tube inlet 41 and the fixed core 50 can be suppressed.

[0477] like Fig.44 As shown, the ring stopper 16 includes a stopper body 161, a stepped surface portion 162, and a gate mark 163. The ring stopper 16 is formed of, for example, resin.

[0478] The stopper body 161 is formed in a substantially annular shape. The step surface portion 162 is formed in a manner that is recessed from the outer edge portion of one end surface of the stopper body 161 toward the other end surface side. Here, the step surface portion 162 does not connect the inner peripheral wall and the outer peripheral wall of the stopper body 161. Two step surface portions 162 are formed at equal intervals in the circumferential direction of the stopper body 161. The gate mark 163 is a protrusion formed when the ring stopper 16 is injection molded, and is formed in a manner that protrudes outward from the outer peripheral wall of the stopper body 161 at the position where the step surface portion 162 is formed. The ring stopper 16 is formed with the step surface portion 162, so that it is easy to distinguish the front and back.

[0479] The ring stopper 16 is installed in the following manner: with the surface without the step surface 162 facing the upper O-ring 3, two specific locations P1 of the surface of the stopper body 161 on which the step surface 162 is formed are pressed, for example with fingers, to push it into the pipe inlet 41 side, so that the inner edge portion passes over the stopper locking portion 413, thereby being installed between the pipe small diameter step surface 412 and the stopper locking portion 413.

[0480] like Fig.46 As shown, in the third comparative embodiment, the stepped surface portion 162 is formed so as to connect the inner peripheral wall and the outer peripheral wall of the stopper body 161. The gate mark 163 is formed so as to protrude from the stepped surface portion 162 in the plate thickness direction.

[0481] In the third comparison method, since the step surface portion 162 is formed in a manner that connects the inner circumferential wall and the outer circumferential wall of the stopper body 161, when the ring stopper 16 is installed to the pipe inlet 41, when the stopper body 161 is pushed into the pipe inlet 41 side by pressing two specific locations P1 of the surface where the step surface portion 162 is formed on the stopper body 161, for example with fingers, the stopper body 161 may be strained or significantly deformed in the portion where the step surface portion 162 is formed.

[0482] On the other hand, in the present embodiment, since the step surface portion 162 does not connect the inner peripheral wall and the outer peripheral wall of the stopper body 161, the strength of the stopper body 161 can be ensured. When the ring stopper 16 is installed to the pipe inlet 41, even if two specific positions P1 of the stopper body 161 are pressed with fingers or the like to push it into the pipe inlet 41 side, the strain and significant deformation of the stopper body 161 can be suppressed.

[0483] like Figures 48 to 50 As shown, the flange inlet 18 includes a flange main body 181, a narrow width portion 182, and a flange protrusion 183. The flange inlet 18 is formed of metal such as stainless steel.

[0484] The flange body 181 is formed in a substantially annular plate shape. The narrow width portion 182 is formed in a portion of the flange body 181 in the circumferential direction and is narrower in radial direction than other portions of the flange body 181. The flange protrusion 183 is formed to protrude radially outward from the narrow width portion 182.

[0485] like Fig.48 As shown, the flange inlet 18 is pressed into the pipe inlet 41 in such a manner that the inner peripheral wall is fitted into the outer peripheral wall of the pipe inlet 41. Here, the inner edge of the surface of the flange inlet 18 on the injection hole 13 side abuts against the flange locking step surface 416 formed in a circular ring-shaped flat surface on the outer peripheral wall of the pipe inlet 41. As a result, the movement of the flange inlet 18 toward the injection hole 13 side is restricted.

[0486] The terminal molded portion 58 is formed with a terminal molded recess 585. The terminal molded recess 585 is formed in a manner recessed from a portion of the outer wall of the terminal molded portion 58 that faces the pipe inlet 41. The flange protrusion 183 is engaged with the terminal molded recess 585. Thus, the terminal molded portion 58 and the connector portion 57 can be positioned in the circumferential direction (rotational direction) of the pipe inlet 41.

[0487] The surface of the flange main body 181 of the flange inlet 18 on the side opposite to the flange locking step surface 416 is exposed from the outer peripheral mold portion 59. The abutment portion 173 of the retainer 17 abuts against the flange inlet 18 exposed from the outer peripheral mold portion 59. The force (load) from the retainer 17 to the combustion chamber 7 side acts on the flange locking step surface 416 via the flange inlet 18.

[0488] The tube inlet 41 is formed with tube annular recesses 414 and 415. The tube annular recess 414 is formed in an annular shape in a manner recessed radially inward from the outer peripheral wall of the flange inlet 18 on the fuel inlet 101 side of the flange inlet 18. The tube annular recess 415 is formed in an annular shape in a manner recessed radially inward from the outer peripheral wall of the flange inlet 18 on the injection hole 13 side of the flange inlet 18.

[0489] In the cross section of the axis including the tube inlet 41, a labyrinth-like path R1 having at least one curved portion is formed at the interface between the tube annular recess 414 and the outer peripheral mold portion 59 (see Fig.48 ) Therefore, even if water enters between the outer peripheral wall of the pipe inlet 41 and the upper end of the outer peripheral mold portion 59, the path R1 becomes an obstacle and the water can be prevented from flowing toward the flange inlet 18 side.

[0490] In addition, in the cross section of the axis including the tube inlet 41, a labyrinth-like path R2 having at least one curved portion is formed at the interface between the tube annular recess 415 and the outer peripheral mold portion 59 (see Fig.48 ). Therefore, even if water enters between the outer edge of the flange inlet 18 and the outer peripheral mold portion 59, the path R2 becomes an obstacle and the water can be prevented from flowing toward the terminal 555 side of the mold hole portion 582.

[0491] like Fig.51 , Fig.52 As shown, a core end portion 500 , a core large diameter portion 52 , and a core small diameter portion 53 are formed at an end portion of the fixed core 50 on the pipe inlet 41 side.

[0492] The core end portion 500 is formed into a substantially cylindrical shape. The core large diameter portion 52 is formed into a substantially cylindrical shape on the side opposite to the injection hole 13 relative to the core end portion 500. The outer diameter of the core large diameter portion 52 is smaller than the outer diameter of the core end portion 500. The core small diameter portion 53 is formed into a substantially cylindrical shape on the side opposite to the injection hole 13 relative to the core large diameter portion 52. The outer diameter of the core small diameter portion 53 is smaller than the outer diameter of the core large diameter portion 52. The tube inlet 41 is pressed into the fixed core 50 in such a manner that the inner peripheral wall of the end portion on the injection hole 13 side is fitted with the outer peripheral wall of the core large diameter portion 52.

[0493] The lower O-ring 5 is provided in a state compressed in the radial direction between the inner peripheral wall of the end portion of the pipe inlet 41 on the injection hole 13 side and the outer peripheral wall of the core small diameter portion 53 .

[0494] A leakage path groove 521 is formed in the core large diameter portion 52. The leakage path groove 521 is formed by cutting a portion of the circumferential direction of the outer peripheral wall of the core large diameter portion 52. Thus, a leakage path 520 is formed as a space between the leakage path groove 521 and the inner peripheral wall of the end portion of the tube inlet 41 on the injection hole 13 side.

[0495] After the tube inlet 41 and the fixed core 50 are pressed in, if the sealing of the lower O-ring 5 is insufficient, when air is blown into the fuel flow path 100, the air flows out from between the core end 500 and the tube inlet 41 through the space between the lower O-ring 5 and the tube inlet 41 or the core small diameter portion 53 and the leakage path 520. Therefore, after the tube inlet 41 and the fixed core 50 are pressed in, air is blown into the fuel flow path 100 to check whether the air flows out from between the core end 500 and the tube inlet 41, thereby confirming whether the sealing of the lower O-ring 5 is ensured.

[0496] like Fig.53 As shown, the conducting portion 554 and the terminal 555 are welded by projection welding, and a welded portion W1 is formed between the punched hole portion 556 and the conducting portion 554 where the terminal 555 and the conducting portion 554 are melted and cooled and solidified.

[0497] like Fig.54 As shown, the end surface of the flange portion 34 of the needle 30 on the injection hole 13 side, that is, the flange portion end surface 341 is formed in an SR shape, that is, a spherical shape. In addition, a tapered portion 401 is formed at the inner edge of the end surface of the movable core 40 on the side opposite to the injection hole 13. The tapered portion 401 is formed in a tapered shape in a manner that approaches the axis of the movable core 40 as it moves from the side opposite to the injection hole 13 to the injection hole 13 side, and can contact the flange portion end surface 341. Therefore, when the fuel injection valve 1 is working, even if the needle 30 tilts relative to the movable core 40 and the contact portion between the movable core 40 and the flange portion 34 is relatively offset, the contact between the flange portion end surface 341 and the tapered portion 401 over the entire circumference can be maintained. As a result, the occurrence of wear caused by partial contact can be suppressed. Furthermore, since the flange end surface 341 is formed into a spherical shape, the contact state between the flange end surface 341 and the tapered surface portion 401 can be always maintained at the same state, and displacement of the needle 30 in the axial direction can be suppressed.

[0498] like Fig.55 As shown in FIG. 1 , a nozzle concave portion 123 and a nozzle convex portion 124 are formed in the nozzle portion 10. The nozzle concave portion 123 is formed in an annular shape in a manner of being recessed radially inward from the outer peripheral wall of the nozzle cylinder portion 12. The nozzle convex portion 124 is formed in an annular shape in a manner of protruding radially outward from the cylindrical bottom surface of the nozzle concave portion 123. The end portion of the nozzle convex portion 124 on the injection hole 13 side and the end portion on the side opposite to the injection hole 13 are formed in a tapered shape.

[0499] A combustion gas seal 19 is provided radially outside the nozzle recess 123 and the nozzle protrusion 124. The combustion gas seal 19 is formed into a substantially cylindrical shape, for example, by resin. The combustion gas seal 19 is compressed in the radial direction between the inner peripheral wall of the cover hole 8 and the nozzle tube 12 when the fuel injection valve 1 is set in the cover hole 8. The combustion gas seal 19 can suppress the combustion gas generated in the combustion chamber 7 from flowing out to the outside of the cylinder head 6 through the cover hole 8.

[0500] In an environment exposed to high-temperature combustion gas, if the combustion pressure continues to act on the combustion gas seal 19, creep deformation, in which the combustion gas seal 19 deforms over time, may occur. Therefore, for example, if the nozzle protrusion 124 is not formed, the combustion gas seal 19 moves to the side opposite to the combustion chamber 7, and the sealing performance of the combustion gas seal 19 may be reduced.

[0501] In this embodiment, when the fuel injection valve 1 is installed in the cover hole 8, the nozzle protrusion 124 bites into the inner peripheral wall of the combustion gas seal 19. As a result, a sealing recess 191 having a shape along the shape of the nozzle protrusion 124 is formed on the inner peripheral wall of the combustion gas seal 19 (see Fig.55 ). Therefore, even if the combustion gas seal 19 undergoes creep deformation, the combustion gas seal 19 can be prevented from moving to the side opposite to the combustion chamber 7 by the seal recess 191 being locked to the nozzle protrusion 124. Therefore, the reduction in the sealing performance of the combustion gas seal 19 can be suppressed.

[0502] (Other embodiments)

[0503] In the third embodiment described above, the axial length of the inner member 81 is greater than the axial length of the outer member 85. In contrast, in other embodiments, the axial length of the inner member 81 may be less than the axial length of the outer member 85.

[0504] In addition, in the above-mentioned embodiment, an example is shown in which the end of the first conical surface on the injection hole side is separated from the end of the second conical surface on the injection hole side. In contrast, in other embodiments, the end of the first conical surface on the injection hole side and the end of the second conical surface on the injection hole side may abut.

[0505] In addition, in the above-mentioned fifth embodiment, the following example is shown: before the intermediate member 95 is pressed between the inner extension portion 92 and the outer extension portion 93, the inner circumferential wall and the outer circumferential wall of the intermediate member 95 are formed into a cone shape, the inner circumferential wall and the outer circumferential wall of the upper shell 90 are formed into a cone shape, and the outer circumferential wall of the inner extension portion 92 and the inner circumferential wall of the outer extension portion 93 are formed into a cone shape. In contrast, in other embodiments, as long as the inner extension portion 92 is forced radially inward or the outer extension portion 93 is forced radially outward when the intermediate member 95 is pressed between the inner extension portion 92 and the outer extension portion 93 so that the inner circumferential wall of the upper shell 90 is in close contact with the outer circumferential wall of the fixed core 50 and the outer circumferential wall of the upper shell 90 is in close contact with the inner circumferential wall of the outer cylinder portion 21 of the shell 20, the inner circumferential wall and outer circumferential wall of the intermediate member 95, the inner circumferential wall and outer circumferential wall of the upper shell 90, the outer circumferential wall of the inner extension portion 92 and the inner circumferential wall of the outer extension portion 93 are not limited to a conical shape, but can also be formed into any shape such as a cylinder.

[0506] In addition, in the fifth embodiment described above, an example in which the intermediate member 95 is formed of a magnetic material is shown. On the other hand, in other embodiments, the intermediate member 95 may be formed of a non-magnetic material.

[0507] In the sixth embodiment described above, an example is shown in which the inner and outer peripheral walls of the upper case 90 are formed into a tapered shape before the upper case 90 is pressed between the fixed core 50 and the case 20. In contrast, in other embodiments, as long as the inner and outer peripheral walls of the upper case 90 are in close contact with the outer peripheral wall of the fixed core 50 and the outer peripheral wall of the upper case 90 are in close contact with the inner peripheral wall of the outer cylinder 21 of the case 20 when the upper case 90 is pressed between the fixed core 50 and the case 20, the inner and outer peripheral walls of the upper case 90 are not limited to the tapered shape, but may be formed into any shape such as a cylinder.

[0508] In addition, in the above-mentioned embodiment, an example is shown in which the upper shell is provided so that the outer peripheral wall of the end portion on the injection hole side is separated from the inner peripheral wall of the outer cylinder portion 21 of the shell 20, or the inner peripheral wall of the end portion on the injection hole side is separated from the outer peripheral wall of the fixed core 50. On the other hand, in other embodiments, the upper shell may be provided so that the outer peripheral wall of the end portion on the injection hole side is in contact with the inner peripheral wall of the outer cylinder portion 21 of the shell 20, or the inner peripheral wall of the end portion on the injection hole side is in contact with the outer peripheral wall of the fixed core 50.

[0509] In addition, in the above-mentioned embodiment, an example is shown in which the upper shell has a cutout portion in a part of the circumferential direction and is formed in a C-shape when viewed from the axial direction. In contrast, in other embodiments, the upper shell may have no cutout portion in a part of the circumferential direction and be formed in a ring shape when viewed from the axial direction.

[0510] In the second to fourth reference forms, the annular protrusion 791 is formed at the center in the axial direction of the inner peripheral wall of the magnetic material ring 79. In contrast, in other reference forms, the annular protrusion 791 may be formed at the end portion on the injection hole 13 side or the end portion on the side opposite to the injection hole 13 in the axial direction of the inner peripheral wall of the magnetic material ring 79.

[0511] Thus, the present disclosure is not limited to the above-described embodiments, and can be implemented in various forms within the scope not departing from the gist of the present disclosure.

[0512] The present disclosure is described based on the embodiments. However, the present disclosure is not limited to the embodiments and configurations. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and methods, and other combinations and methods containing only one element, above or below them also fall within the scope and concept of the present disclosure.

Claims

1. A fuel injection valve, It is characterized in that have: A nozzle portion having a spray hole for spraying fuel and a valve seat formed around the spray hole; A cylindrical housing is arranged to be connected to a side of the nozzle portion opposite to the spray hole; A needle, one end of which is separated from the valve seat or abuts against the valve seat, thereby opening and closing the spray hole; a movable core disposed radially outside the needle so as to be relatively movable in the axial direction relative to the needle; a cylindrical fixed core disposed on the side opposite to the injection hole relative to the movable core, wherein at least a portion of the fixed core in the axial direction is located radially inward of the housing; a coil disposed between the fixed core and the housing, and capable of attracting the movable core together with the needle toward the fixed core by energizing the coil; as well as The upper shell is disposed between the fixed core and the shell on the side opposite to the nozzle hole relative to the coil, and can form a magnetic circuit together with the fixed core and the shell. The upper shell has a first conical surface formed on the outer peripheral wall and a first cylindrical surface formed on the inner peripheral wall. The housing has a second tapered surface facing the first tapered surface in a radial direction. The fixed core has a second cylindrical surface facing the first cylindrical surface in the radial direction. The first tapered surface and the second tapered surface are formed in a tapered shape with a diameter decreasing as going from the side opposite to the injection hole toward the injection hole side. The upper shell is formed of a magnetic material into a ring or C shape. The upper shell is constructed as follows: the upper shell is inserted between the fixed core and the shell from the side opposite to the nozzle relative to the coil, and the first cylindrical surface and the second cylindrical surface are abutted and tightly attached to each other while the first conical surface and the second conical surface are axially slid and the upper shell itself is deformed radially inward.

2. A fuel injection valve, It is characterized in that have: A nozzle portion having a spray hole for spraying fuel and a valve seat formed around the spray hole; A cylindrical housing is arranged to be connected to a side of the nozzle portion opposite to the spray hole; A needle, one end of which is separated from the valve seat or abuts against the valve seat, thereby opening and closing the spray hole; a movable core disposed radially outside the needle so as to be relatively movable in the axial direction relative to the needle; a cylindrical fixed core disposed on the side opposite to the injection hole relative to the movable core, wherein at least a portion of the fixed core in the axial direction is located radially inward of the housing; a coil, which is disposed between the fixed core and the housing and can attract the movable core together with the needle toward the fixed core by energizing the coil; as well as The upper shell is disposed between the fixed core and the shell on the side opposite to the nozzle hole relative to the coil, and can form a magnetic circuit together with the fixed core and the shell. The upper shell has a first conical surface formed on the inner peripheral wall and a first cylindrical surface formed on the outer peripheral wall. The fixed core has a second tapered surface facing the first tapered surface in the radial direction. The housing has a second cylindrical surface facing the first cylindrical surface in the radial direction. The first tapered surface and the second tapered surface are formed in a tapered shape with a diameter decreasing from the injection hole side to the side opposite to the injection hole. The upper shell is formed of a magnetic material into a ring or C shape. The upper shell is constructed as follows: the upper shell is inserted between the fixed core and the shell from the side opposite to the nozzle relative to the coil, and the first cylindrical surface and the second cylindrical surface are abutted and tightly attached to each other while the first conical surface and the second conical surface are axially slid and the upper shell itself is deformed radially outward.

3. The fuel injection valve according to claim 2, It is characterized in that When the first conical surface and the second conical surface are not facing each other in the radial direction, the outer diameter of the first cylindrical surface is smaller than the inner diameter of the second cylindrical surface. The first cylindrical surface abuts against the second cylindrical surface in a state where the first tapered surface and the second tapered surface face each other in the radial direction.

4. A fuel injection valve, It is characterized in that have: A nozzle portion having a spray hole for spraying fuel and a valve seat formed around the spray hole; A cylindrical housing is arranged to be connected to a side of the nozzle portion opposite to the spray hole; A needle, one end of which is separated from the valve seat or abuts against the valve seat, thereby opening and closing the spray hole; a movable core disposed radially outside the needle so as to be relatively movable in the axial direction relative to the needle; a cylindrical fixed core disposed on the side opposite to the injection hole relative to the movable core, wherein at least a portion of the fixed core in the axial direction is located radially inward of the housing; a coil, which is disposed between the fixed core and the housing and can attract the movable core together with the needle toward the fixed core by energizing the coil; as well as The upper shell is disposed between the fixed core and the shell on the side opposite to the nozzle hole relative to the coil, and can form a magnetic circuit together with the fixed core and the shell. The upper housing includes an inner member and an outer member disposed radially outward of the inner member. The inner member has a first tapered surface formed on the outer peripheral wall and a first cylindrical surface formed on the inner peripheral wall. The outer member has a second tapered surface formed on the inner peripheral wall so as to face the first tapered surface in the radial direction, and a second cylindrical surface formed on the outer peripheral wall. The fixed core has a third cylindrical surface facing the first cylindrical surface in the radial direction. The housing has a fourth cylindrical surface facing the second cylindrical surface in the radial direction. The upper shell is formed of a magnetic material into a ring or C shape. The upper shell is constructed such that, while the outer member is inserted between the fixed core and the shell, the inner member is inserted between the fixed core and the outer member from the side opposite to the nozzle relative to the coil, so that the first conical surface and the second conical surface are axially slid and the inner member is deformed radially inwardly so that the first cylindrical surface abuts and fits tightly against the third cylindrical surface, and the outer member is deformed radially outwardly so that the second cylindrical surface abuts and fits tightly against the fourth cylindrical surface.

5. The fuel injection valve according to claim 4, It is characterized in that In a state where the first conical surface and the second conical surface are not facing each other in the radial direction, the inner diameter of the first cylindrical surface is larger than the outer diameter of the third cylindrical surface, or the outer diameter of the second cylindrical surface is smaller than the inner diameter of the fourth cylindrical surface, In a state where the first tapered surface and the second tapered surface face each other in the radial direction, the first cylindrical surface abuts against the third cylindrical surface, or the second cylindrical surface abuts against the fourth cylindrical surface.

6. The fuel injection valve according to claim 4 or 5, It is characterized in that The axial length of the inner member is greater than the axial length of the outer member.

7. The fuel injection valve according to claim 4 or 5, It is characterized in that An end portion of the first tapered surface on the injection hole side is separated from an end portion of the second tapered surface on the injection hole side.

8. A fuel injection valve, It is characterized in that have: A nozzle portion having a spray hole for spraying fuel and a valve seat formed around the spray hole; A cylindrical housing is arranged to be connected to a side of the nozzle portion opposite to the spray hole; A needle, one end of which is separated from the valve seat or abuts against the valve seat, thereby opening and closing the spray hole; a movable core disposed radially outside the needle so as to be relatively movable in the axial direction relative to the needle; a cylindrical fixed core disposed on the side opposite to the injection hole relative to the movable core, wherein at least a portion of the fixed core in the axial direction is located radially inward of the housing; a coil disposed between the fixed core and the housing, and capable of attracting the movable core together with the needle toward the fixed core by energizing the coil; as well as The upper shell is disposed between the fixed core and the shell on the side opposite to the nozzle hole relative to the coil, and can form a magnetic circuit together with the fixed core and the shell. The upper shell has a bottom, an inner extension portion formed in a manner extending from an inner edge portion of the bottom in an axial direction of the bottom, and an outer extension portion formed in a manner extending from an outer edge portion of the bottom in an axial direction of the bottom. The upper shell is formed of a magnetic material into a ring or C shape. The fuel injection valve further includes an intermediate member provided between the inner extension portion and the outer extension portion. The upper shell is constructed such that the inner circumferential wall of the intermediate member and the outer circumferential wall of the inner extension portion slide axially, and the outer circumferential wall of the intermediate member and the inner circumferential wall of the outer extension portion slide axially, and the inner extension portion is deformed radially inwardly and the outer extension portion is deformed radially outwardly by inserting the upper shell between the fixed core and the shell from the side opposite to the injection hole relative to the coil, and inserting the intermediate member between the inner extension portion and the outer extension portion, so that the inner circumferential wall of the intermediate member and the outer circumferential wall of the inner extension portion are tightly attached, the outer circumferential wall of the intermediate member and the inner circumferential wall of the outer extension portion are tightly attached, the inner circumferential wall of the inner extension portion and the outer circumferential wall of the outer extension portion are tightly attached to the inner circumferential wall of the shell.

9. The fuel injection valve according to claim 8, It is characterized in that The intermediate member is provided so as to be able to bias the inner extending portion radially inward of the bottom portion.

10. The fuel injection valve according to claim 8 or 9, It is characterized in that The intermediate member is provided so as to be able to bias the outer extending portion toward the radially outer side of the bottom portion.

11. The fuel injection valve according to claim 8 or 9, It is characterized in that The intermediate member can form a magnetic circuit together with the upper case.

12. The fuel injection valve according to claim 8 or 9, It is characterized in that The upper case is provided so that an outer peripheral wall of an end portion on the injection hole side is separated from an inner peripheral wall of the case, or an inner peripheral wall of an end portion on the injection hole side is separated from an outer peripheral wall of the fixed core.

13. The fuel injection valve according to claim 8 or 9, It is characterized in that The upper housing has a cutout portion in a portion in the circumferential direction and is formed in a C-shape when viewed from the axial direction.

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