JP6669282B2 - Fuel injection device - Google Patents

Description

  The present invention relates to a fuel injection device that supplies fuel to an internal combustion engine.

  Conventionally, a fuel injection device capable of injecting high-pressure liquid fuel has been known. For example, in a fuel injection device disclosed in Patent Literature 1, three housings are continuously arranged coaxially and connected by welding to form a housing. A fuel passage through which the injected fuel flows is formed inside the housing.

JP 2013-217307 A

  In the fuel injection device of Patent Literature 1, among the three cylindrical members constituting the housing, the cylindrical members at both ends in the axial direction are formed of a magnetic material, and the intermediate cylindrical member is formed of a nonmagnetic material. A coil is provided radially outside the intermediate cylindrical member and the fixed core. With this configuration, when the coil is energized, the movable core can be attracted to the fixed core.

  In the fuel injection device of Patent Document 1, when the pressure of the fuel in the fuel passage becomes larger than a predetermined value, the housing may be deformed in the radial direction. In particular, when the vicinity of the connection portion of the three cylindrical members is deformed in the radial direction, stress concentrates on the connection portion, the welded portion is torn, and a gap may be generated between the respective cylindrical members. If a gap is formed between the cylindrical members, fuel in the fuel passage may leak out of the housing.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection device capable of injecting high-pressure fuel while suppressing fuel leakage from a fuel passage to the outside of a housing. .

The fuel injection device of the present invention includes a nozzle portion, a housing, a needle, an inner protruding portion, and an outer protruding portion.
The nozzle portion has a nozzle cylinder, a nozzle bottom, an injection hole, and a valve seat.
The nozzle tube is formed in a tube shape. The nozzle bottom covers one end of the nozzle cylinder. The injection hole connects the surface of the nozzle bottom portion on the side of the nozzle cylinder and the surface on the side opposite to the nozzle cylinder, and fuel is injected. The valve seat is formed in an annular shape around the injection hole on the side of the nozzle cylinder at the bottom of the nozzle.

The housing has a first tubular member, a second tubular member, a third tubular member, and a fuel passage.
The first cylinder member is provided so that one end thereof is connected to the side opposite to the nozzle bottom of the nozzle cylinder.
The second tubular member is provided such that one end is located on the other end side of the first tubular member.
The third cylinder member is provided such that one end is located on the other end side of the second cylinder member.
The fuel passage is formed inside the first cylindrical member, the second cylindrical member, and the third cylindrical member so as to guide the fuel to the injection hole.

The needle is provided so as to be able to reciprocate in the fuel passage, and opens and closes the injection hole when one end is separated from the valve seat or comes into contact with the valve seat.
The inner protruding portion is an end surface of the second cylinder member that is an end surface of the second cylinder member or the third cylinder member on the side of the third cylinder member, or an end surface of the third cylinder member that is an end surface of the second cylinder member or the second cylinder member. And is integrally formed with the second or third cylindrical member so as to protrude from the third cylindrical member and be connected to the third or second cylindrical member.
The outer protruding portion is an end surface of the third cylinder member that is the other end surface of the second cylinder member or the third cylinder member, or an end surface of the second cylinder member that is an end surface of the third cylinder member. From the third cylindrical member or the second cylindrical member so that the inner wall is in contact with the second cylindrical member or the third cylindrical member and the inner wall is in contact with the outer wall of the inner protruding portion.

According to the present invention, the outer protrusion that is integral with the third cylindrical member or the second cylindrical member is positioned radially outside the inner protrusion that is integral with the second cylindrical member or the third cylindrical member, and the outer wall of the inner protrusion is , Abutting against the inner wall of the outer protruding portion. Therefore, even if the pressure of the fuel in the fuel passage increases, the radial deformation of the inner protruding portion can be suppressed. Thereby, it is possible to suppress concentration of stress on the connecting portion between the inner protruding portion and the third or second cylindrical member and the connecting portion between the outer protruding portion and the second or third cylindrical member. Can be. As a result, it is possible to suppress the tearing of the connection location and the generation of a gap at the connection location. Therefore, it is possible to prevent the fuel from leaking from the fuel passage to the outside of the housing via the gap. Therefore, the present invention can inject high-pressure fuel while suppressing fuel leakage from the fuel passage to the outside of the housing.
Further, in the present invention, the outer protruding end surface, which is the end surface of the outer protruding portion, is in contact with the end surface of the second cylindrical member or the end surface of the third cylindrical member. The end surface or the end of the inner protruding portion and the outer protruding end surface are formed at positions shifted in the axial direction. The housing has a welded portion for welding and fixing the outer protruding end face to the end face of the second tubular member or the end face of the third tubular member. The length of the welded portion in the radial direction of the second cylindrical member is at least longer than the outer protruding end surface.

In another fuel injection device of the present invention, the inner protruding portion may be an end surface of the second cylinder member, which is an end surface of one of the second cylinder member and the first cylinder member on the first cylinder member side, or the second cylinder member side. The second cylindrical member or the first cylindrical member is formed integrally with the first cylindrical member so as to protrude cylindrically from the end surface of the first cylindrical member which is the end surface of the second cylindrical member.
The outer protruding portion is an end surface of the first cylinder member which is the other end surface of the second cylinder member or the first cylinder member on the side of the second cylinder member, or an end surface of the second cylinder member which is an end surface on the side of the first cylinder member. And is integrally formed with the first or second cylindrical member so that the inner wall contacts the second or first cylindrical member and the inner wall contacts the outer wall of the inner protruding portion.

According to the present invention, the outer protrusion integrated with the first cylindrical member or the second cylindrical member is located radially outside the inner protrusion integrated with the second cylindrical member or the first cylindrical member. , Abutting against the inner wall of the outer protruding portion. Therefore, even if the pressure of the fuel in the fuel passage increases, the radial deformation of the inner protruding portion can be suppressed. This suppresses concentration of stress on the connecting portion of the inner protruding portion with the first or second cylindrical member and the connecting portion of the outer protruding portion with the second or first cylindrical member. Can be. As a result, it is possible to suppress the tearing of the connection location and the generation of a gap at the connection location. Therefore, it is possible to prevent the fuel from leaking from the fuel passage to the outside of the housing via the gap. Therefore, the present invention can inject high-pressure fuel while suppressing fuel leakage from the fuel passage to the outside of the housing.
Further, in the present invention, the outer protruding end surface, which is the end surface of the outer protruding portion, is in contact with the end surface of the second cylindrical member or the end surface of the first cylindrical member. The end surface or the end of the inner protruding portion and the outer protruding end surface are formed at positions shifted in the axial direction. The housing has a welded portion for welding and fixing the outer protruding end face and the end face of the second tubular member or the end face of the first tubular member. The length of the welded portion in the radial direction of the second cylindrical member is at least longer than the outer protruding end surface.

FIG. 1 is a sectional view showing a fuel injection device according to a first embodiment of the present invention. The enlarged view of the II section of FIG. FIG. 6 is a cross-sectional view illustrating an inner protrusion and an outer protrusion of a fuel injection device according to a second embodiment of the present invention. FIG. 9 is a sectional view showing an inner protrusion and an outer protrusion of a fuel injection device according to a third embodiment of the present invention. FIG. 14 is a sectional view showing an inner protrusion and an outer protrusion of a fuel injection device according to a fourth embodiment of the present invention. FIG. 14 is a sectional view showing an inner protrusion and an outer protrusion of a fuel injection device according to a fifth embodiment of the present invention. FIG. 14 is a sectional view showing an inner protrusion and an outer protrusion of a fuel injection device according to a sixth embodiment of the present invention. FIG. 14 is a sectional view showing an inner protrusion and an outer protrusion of a fuel injection device according to a seventh embodiment of the present invention. FIG. 16 is a sectional view showing an inner protrusion and an outer protrusion of a fuel injection device according to an eighth embodiment of the present invention. FIG. 14 is a sectional view showing an inner projecting portion and an outer projecting portion of a fuel injection device according to a ninth embodiment of the present invention. FIG. 14 is a sectional view showing an inner protrusion and an outer protrusion of a fuel injection device according to a tenth embodiment of the present invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.
(1st Embodiment)
FIG. 1 shows a fuel injection device according to a first embodiment of the present invention. The fuel injection device 1 is used, for example, in a direct-injection gasoline engine as an internal combustion engine (not shown), and injects and supplies gasoline as fuel to the engine.

The fuel injection device 1 includes a nozzle portion 10, a housing 20, a needle 30, a movable core 40, a fixed core 50, a spring 52 as a valve seat side biasing member, a gap forming member 54, a coil 57, inner projecting portions 60 and 80, The outer projections 70 and 90 are provided.
The nozzle portion 10 is formed of a metal such as martensitic stainless steel, for example. The nozzle portion 10 is subjected to a quenching process so as to have a predetermined hardness. As shown in FIG. 1, the nozzle unit 10 has a nozzle cylinder 11, a nozzle bottom 12, an injection hole 13, and a valve seat 14.

The nozzle cylinder 11 is formed in a cylindrical shape. The nozzle bottom 12 closes one end of the nozzle cylinder 11. The injection hole 13 connects the surface of the nozzle bottom portion 12 on the side of the nozzle cylinder 11, that is, the inner wall, and the surface on the side opposite to the nozzle cylinder 11, that is, the outer wall, and fuel is injected. In the present embodiment, a plurality of injection holes 13 are formed in the nozzle bottom 12. The valve seat 14 is formed in an annular shape around the injection hole 13 on the nozzle cylinder portion 11 side of the nozzle bottom portion 12.
The housing 20 has a first tubular member 21, a second tubular member 22, a third tubular member 23, an inlet 24, a filter 25, and the like.

  The first tubular member 21, the second tubular member 22, and the third tubular member 23 are all formed in a substantially cylindrical shape. The first tubular member 21, the second tubular member 22, and the third tubular member 23 are arranged so as to be coaxial (axis Ax1) in the order of the first tubular member 21, the second tubular member 22, and the third tubular member 23, and They are connected to each other via the protrusion 60, the outer protrusion 70, the inner protrusion 80, and the outer protrusion 90. The inner protrusion 60, the outer protrusion 70, the inner protrusion 80, and the outer protrusion 90 will be described later in detail.

  The first cylinder member 21 and the third cylinder member 23 are made of a magnetic material such as ferrite stainless steel, and are subjected to a magnetic stabilization process. The first cylinder member 21 and the third cylinder member 23 have relatively low hardness. On the other hand, the second cylindrical member 22 is formed of a non-magnetic material such as austenitic stainless steel. The hardness of the second cylindrical member 22 is higher than the hardness of the first cylindrical member 21 and the third cylindrical member 23.

  The inside of the end of the first cylinder member 21 opposite to the second cylinder member 22 is connected to the end of the nozzle cylinder 11 of the nozzle section 10 opposite to the nozzle bottom 12. The first cylindrical member 21 and the nozzle portion 10 are connected by, for example, welding.

  The inlet part 24 is formed in a cylindrical shape from a magnetic material such as ferrite stainless steel. The inlet 24 is provided such that one end is connected to the inside of the end of the third cylindrical member 23 opposite to the second cylindrical member 22. In the present embodiment, the inlet portion 24 is integrally formed of the same material as the third cylindrical member 23 (see FIG. 1).

A fuel passage 26 is formed inside the housing 20. The fuel passage 26 is connected to the injection hole 13. A pipe (not shown) is connected to the inlet 24 on the side opposite to the third cylindrical member 23. Thus, the fuel from the fuel supply source flows into the fuel passage 26 via the pipe. The fuel passage 26 guides the fuel to the injection hole 13.
The filter 25 is provided inside the inlet 24. The filter 25 collects foreign matter in the fuel flowing into the fuel passage 26.

  The needle 30 is formed in a rod shape from a metal such as a martensitic stainless steel, for example. The needle 30 is subjected to a quenching treatment so as to have a predetermined hardness. The hardness of the needle 30 is set substantially equal to the hardness of the nozzle unit 10.

  The needle 30 is accommodated in the housing 20 so as to be able to reciprocate in the fuel passage 26 in the direction of the axis Ax1 of the housing 20. The needle 30 has a needle body 31, a seat portion 32, a flange portion 33, a large diameter portion 35, and the like.

  The needle main body 31 is formed in a substantially cylindrical shape. The seat portion 32 is formed at an end of the needle body 31 on the valve seat 14 side, and is capable of abutting on the valve seat 14. The flange portion 33 is formed in an annular shape, and is provided radially outward of an end of the needle body 31 opposite to the valve seat 14. The flange 33 is formed integrally with the needle body 31.

  The large diameter portion 35 is provided integrally with the needle main body 31 near the seat portion 32 of the needle main body 31. The large diameter portion 35 is formed such that the outer diameter is larger than the outer diameter of the end of the needle body 31 on the valve seat 14 side. The large-diameter portion 35 is formed such that the outer wall slides on the inner wall of the nozzle tube portion 11 of the nozzle portion 10. Thus, the needle 30 is guided to reciprocate in the direction of the axis Ax1 at the end on the valve seat 14 side. A notch 36 is formed in the large diameter portion 35 so that a plurality of portions of the outer wall in the circumferential direction are cut out. Thereby, the fuel can flow between the notch 36 and the inner wall of the nozzle cylinder 11 of the nozzle 10.

  An axial hole 37 extending along the axis Ax2 of the needle main body 31 is formed at an end of the needle main body 31 opposite to the seat portion 32. That is, the end of the needle body 31 opposite to the seat portion 32 is formed in a hollow cylindrical shape. The needle body 31 has a radial hole 38 extending in the radial direction of the needle body 31 so as to connect an end of the axial hole 37 on the valve seat 14 side to a space outside the needle body 31. ing. Thus, the fuel in the fuel passage 26 can flow through the axial hole 37 and the radial hole 38.

  The needle 30 opens and closes the injection hole 13 when the seat portion 32 is separated (separated) from the valve seat 14 or abuts (seated) on the valve seat 14. Hereinafter, the direction in which the needle 30 separates from the valve seat 14 is referred to as a valve opening direction, and the direction in which the needle 30 contacts the valve seat 14 is referred to as a valve closing direction.

  The movable core 40 is formed in a substantially cylindrical shape using a magnetic material such as a ferrite stainless steel. The movable core 40 has been subjected to a magnetic stabilization process. The hardness of the movable core 40 is relatively low, and is substantially equal to the hardness of the first cylindrical member 21 and the third cylindrical member 23 of the housing 20.

  The movable core 40 has a shaft hole 41, a hole 42, a recess 43, and the like. The shaft hole 41 is formed to extend along the axis Ax3 of the movable core 40. The hole 42 is formed so as to connect the end surface of the movable core 40 on the valve seat 14 side and the end surface on the opposite side to the valve seat 14. The hole 42 has a cylindrical inner wall. Here, the hole 42 is formed so that the axis is parallel to the axis Ax3 of the movable core 40. In the present embodiment, four holes 42 are formed at equal intervals in the circumferential direction of the movable core 40.

  The recess 43 is formed at the center of the movable core 40 so as to be circularly recessed from the end face of the movable core 40 on the valve seat 14 side to the opposite side to the valve seat 14. Here, the shaft hole portion 41 is formed so as to connect the bottom of the concave portion 43 of the movable core 40 and the end face opposite to the valve seat 14.

  The movable core 40 is housed in the housing 20 with the needle main body 31 of the needle 30 inserted through the shaft hole 41. The movable core 40 is provided coaxially with the needle main body 31 of the needle 30. The inner diameter of the shaft hole 41 of the movable core 40 is set equal to or slightly larger than the outer diameter of the needle body 31 of the needle 30. Therefore, the movable core 40 can move relative to the needle 30 while the inner wall of the shaft hole 41 slides against the outer wall of the needle body 31 of the needle 30. Further, similarly to the needle 30, the movable core 40 is housed in the housing 20 so as to be able to reciprocate in the fuel passage 26 in the direction of the axis Ax1 of the housing 20. The fuel in the fuel passage 26 can flow through the hole 42.

  Note that the outer diameter of the movable core 40 is set smaller than the inner diameters of the first tubular member 21 and the second tubular member 22 of the housing 20. Therefore, when the movable core 40 reciprocates in the fuel passage 26, the outer wall of the movable core 40 and the inner walls of the first tubular member 21 and the second tubular member 22 do not slide.

  The collar portion 33 of the needle 30 has an annular contact surface 34 on the valve seat 14 side. The contact surface 34 is tapered so as to approach the axis Ax2 from one side to the other side in the direction of the axis Ax2. The movable core 40 has a contact surface 44 at an end of the shaft hole 41 opposite to the concave portion 43. The contact surface 44 is formed in a tapered shape so as to approach the axis Ax3 from one side to the other side in the direction of the axis Ax3. Here, the contact surface 34 of the flange 33 and the contact surface 44 of the movable core 40 can be brought into contact by surface contact.

  The movable core 40 is provided so as to be relatively movable with respect to the needle 30 such that the contact surface 44 contacts the contact surface 34 or the contact surface 44 can be separated from the contact surface 34. The movable core 40 can reciprocate in the fuel passage 26 together with the needle 30 when, for example, the contact surface 44 is in contact with the contact surface 34.

  The fixed core 50 is formed in a substantially cylindrical shape from a magnetic material such as ferrite stainless steel. The fixed core 50 has been subjected to a magnetic stabilization process. The hardness of the fixed core 50 is relatively low, and is substantially equal to the hardness of the movable core 40. The fixed core 50 is provided on the movable core 40 on the side opposite to the valve seat 14. The fixed core 50 is provided so that the outer wall is connected to the inner wall of the third cylindrical member 23 of the housing 20, and the end opposite to the valve seat 14 is connected to the inlet 24. In the present embodiment, the fixed core 50 is integrally formed of the same material as the third cylindrical member 23 and the inlet 24 (see FIG. 1). The end surface of the fixed core 50 on the valve seat 14 side can contact the end surface of the movable core 40 on the fixed core 50 side.

  The fixed core 50 is provided such that the flange portion 33 of the needle 30 in a state where the seat portion 32 is in contact with the valve seat 14 is located inside the end on the valve seat 14 side. Inside the fixed core 50, a cylindrical adjusting pipe 51 is press-fitted.

  The spring 52 is, for example, a coil spring, and is provided between the adjusting pipe 51 inside the fixed core 50 and the flange 33 of the needle 30. One end of the spring 52 is in contact with the adjusting pipe 51.

  The gap forming member 54 is provided between the needle 30 and the spring 52. The gap forming member 54 is formed of, for example, a metal such as martensitic stainless steel. The hardness of the gap forming member 54 is set substantially equal to the hardness of the needle 30.

  In this embodiment, the gap forming member 54 is formed in a bottomed cylindrical shape. The gap forming member 54 has a plate 541 and a leg 542. The plate portion 541 is formed in a substantially disc shape. The leg 542 is formed integrally with the plate 541 so as to extend cylindrically from the outer edge of the plate 541 toward the valve seat 14. The gap forming member 54 is provided such that the flange 33 of the needle 30 is located inside the leg 542.

  Here, the inner diameter of the leg 542 of the gap forming member 54 is set to be equal to or slightly larger than the outer diameter of the flange 33. Therefore, the gap forming member 54 is relatively movable with respect to the needle 30 while the inner wall of the leg 542 slides against the outer wall of the flange 33. The end surface of the plate portion 541 on the leg portion 542 side can contact the end surface of the needle 30 on the side opposite to the valve seat 14 of the needle body 31 and the flange portion 33. The end of the leg 542 on the side opposite to the plate 541 can contact the end surface of the movable core 40 on the fixed core 50 side.

  The fixed core 50 has a tubular member 53 inside the end on the movable core 40 side. The cylindrical member 53 is formed of a metal such as martensitic stainless steel, for example. The hardness of the cylindrical member 53 is set substantially equal to the hardness of the gap forming member 54. The gap forming member 54 is located inside the end of the cylindrical member 53 on the movable core 40 side. The inner diameter of the cylindrical member 53 is equal to the outer diameter of the plate portion 541 and the leg portion 542 of the gap forming member 54 or slightly larger than the outer diameter of the plate portion 541 and the leg portion 542 of the gap forming member 54. Therefore, the gap forming member 54 is relatively movable with respect to the tubular member 53 while the outer walls of the plate portion 541 and the leg portion 542 slide on the inner wall of the tubular member 53. Thus, the needle 30 is guided by the tubular member 53 through the leg 542 of the gap forming member 54 in the reciprocating movement in the direction of the axis Ax2 at the end on the flange 33 side.

  The other end of the spring 52 is in contact with an end surface of the plate 541 of the gap forming member 54 on the side opposite to the leg 542. The spring 52 urges the gap forming member 54 toward the valve seat 14. When the plate portion 541 of the gap forming member 54 is in contact with the needle 30, the spring 52 can bias the needle 30 toward the valve seat 14 via the gap forming member 54, that is, in the valve closing direction. The spring 52 can bias the movable core 40 toward the valve seat 14 via the gap forming member 54 when the leg 542 of the gap forming member 54 is in contact with the movable core 40. The biasing force of the spring 52 is adjusted by the position of the adjusting pipe 51 with respect to the fixed core 50.

  In the present embodiment, the leg 542 of the gap forming member 54 is formed such that the axial length is longer than the axial length of the flange 33. For this reason, the gap forming member 54 contacts the contact surface 34 of the flange 33 and the contact surface 44 of the movable core 40 with the plate portion 541 contacting the needle 30 and the leg portion 542 contacting the movable core 40. A gap C1 can be formed therebetween.

  The gap forming member 54 has a hole 543. The hole 543 is formed so as to penetrate the center of the plate 541 in the plate thickness direction. As a result, the fuel on the side opposite to the valve seat 14 of the gap forming member 54 in the fuel passage 26 passes through the hole 543, the axial hole 37 of the needle 30, and the radial hole 38 of the movable core 40. It can be distributed to the valve seat 14 side.

  In the present embodiment, the fuel injection device 1 further includes a regulating portion 55 and a spring 56. The restricting portion 55 is formed of, for example, a metal such as stainless steel. The restricting portion 55 has a cylindrical portion 551, a spring seat portion 552, and the like. The regulating portion 55 is provided on the needle 30 such that the needle main body 31 of the needle 30 is inserted inside the cylindrical portion 551. Here, the movable core 40 is provided so as to be able to reciprocate in the axial direction between the flange portion 33 of the needle 30 and the regulating portion 55. The bottom of the concave portion 43 of the movable core 40 can contact the end of the cylindrical portion 551 of the regulating portion 55 on the movable core 40 side.

  In the present embodiment, the restricting portion 55 is provided such that the inner wall of the end of the cylindrical portion 551 on the movable core 40 side is fitted to the outer wall of the needle main body 31. Therefore, the restricting portion 55 cannot move relative to the needle 30. Thus, the restricting portion 55 can restrict the relative movement of the movable core 40 toward the valve seat 14 with respect to the needle 30 by bringing the cylindrical portion 551 into contact with the movable core 40.

The inner diameter of the end of the cylindrical portion 551 on the valve seat 14 side is set to be larger than the inner diameter of the end on the movable core 40 side. Therefore, a cylindrical gap is formed between the inner wall of the end of the cylindrical portion 551 on the valve seat 14 side and the outer wall of the needle body 31 of the needle 30. The cylindrical gap is connected to the radial hole 38 of the needle 30. Therefore, the fuel in the axial hole 37 of the needle 30 can flow toward the valve seat 14 through the radial hole 38 and the cylindrical gap inside the cylindrical portion 551.
The spring seat portion 552 is formed integrally with the tubular portion 551 so as to extend annularly outward in the radial direction from the end of the tubular portion 551 on the valve seat 14 side.

  The spring 56 is, for example, a coil spring, and is provided such that one end contacts the bottom of the concave portion 43 of the movable core 40 and the other end contacts the spring seat 552. The spring 56 can bias the movable core 40 toward the fixed core 50. The biasing force of the spring 56 is smaller than the biasing force of the spring 52.

  When the spring 52 urges the gap forming member 54 toward the valve seat 14, the plate portion 541 of the gap forming member 54 abuts on the needle 30, and the seat portion 32 of the needle 30 is pressed against the valve seat 14. At this time, when the spring 56 urges the movable core 40 toward the fixed core 50, the leg portion 542 of the gap forming member 54 and the end surface of the movable core 40 on the fixed core 50 side come into contact with each other. In this state, a gap C1 is formed between the contact surface 34 of the flange 33 of the needle 30 and the contact surface 44 of the movable core 40, and the bottom of the concave portion 43 of the movable core 40 and the cylindrical portion 551 of the regulating portion 55 are formed. Is formed between them.

  In the present embodiment, the end of the needle 30 on the valve seat 14 side is supported by the inner wall of the nozzle cylinder 11 of the nozzle unit 10 so as to be able to reciprocate, and the end on the flange 33 side is the gap forming member 54 and the cylinder member. Reciprocally supported by the inner wall 53. In this manner, the needle 30 is guided by two portions in the direction of the axis Ax2 to reciprocate in the direction of the axis Ax2.

  The coil 57 is formed in a substantially cylindrical shape, and is provided so as to surround the radial outside of the second cylindrical member 22 and the third cylindrical member 23 in the housing 20. A cylindrical holder 15 is provided outside the coil 57 in the radial direction so as to cover the coil 57. The holder 15 is formed of a magnetic material such as a ferritic stainless steel.

  The coil 57 generates a magnetic force when electric power is supplied (energized). When a magnetic force is generated in the coil 57, a magnetic circuit is formed in the fixed core 50, the movable core 40, the first tubular member 21, the holder 15, and the third tubular member 23. Thereby, a magnetic attractive 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. At this time, the movable core 40 moves in the valve opening direction while accelerating the gap C1, and the contact surface 44 collides with the contact surface 34 of the flange 33 of the needle 30. As a result, the needle 30 moves in the valve opening direction, the seat portion 32 is separated from the valve seat 14, and the valve is opened. As a result, the injection hole 13 is opened. In this way, when the coil 57 is energized, it is possible to attract the movable core 40 toward the fixed core 50 and move the needle 30 to the side opposite to the valve seat 14.

  As described above, in the present embodiment, the gap forming member 54 forms the gap C1 between the flange 33 and the movable core 40 in the valve-closed state. It can be accelerated at C <b> 1 to collide with the flange 33. Thus, even when the pressure in the fuel passage 26 is relatively high, the needle 30 can be opened without increasing the power supplied to the coil 57.

  When the movable core 40 is attracted toward the fixed core 50 (in the valve opening direction) by the magnetic attraction, the end face of the fixed core 50 collides with the end face of the fixed core 50 on the movable core 40 side. Thereby, the movement of the movable core 40 in the valve opening direction is restricted.

  When the energization of the coil 57 is stopped in a state where the movable core 40 is attracted to the fixed core 50 side, the needle 30 and the movable core 40 are moved to the valve seat 14 side by the urging force of the spring 52 via the gap forming member 54. It is energized to. As a result, the needle 30 moves in the valve closing direction, and the seat portion 32 contacts the valve seat 14 to close the valve. As a result, the injection hole 13 is closed.

  In the present embodiment, after the seat portion 32 contacts the valve seat 14, the movable core 40 relatively moves toward the valve seat 14 with respect to the needle 30 due to inertia. At this time, the restricting portion 55 can restrict excessive movement of the movable core 40 toward the valve seat 14 by contacting the movable core 40. Thereby, it is possible to suppress a decrease in the responsiveness of the next valve opening. In addition, the urging force of the spring 56 can reduce the impact when the movable core 40 comes into contact with the regulating portion 55, and can suppress the secondary valve opening due to the needle 30 bouncing on the valve seat 14. Further, the restricting portion 55 restricts the movement of the movable core 40 toward the valve seat 14, so that excessive compression of the spring 56 can be suppressed, and the movable core 40 is opened by the restoring force of the excessively compressed spring 56. The secondary valve can be prevented from being opened by being urged in the direction and colliding against the flange portion 33 again.

  As shown in FIG. 1, the outside of the inlet 24 and the third cylindrical member 23 in the radial direction is molded with resin. The connector part 58 is formed in the mold part. A terminal 581 for supplying electric power to the coil 57 is insert-molded in the connector portion 58. A cylindrical member 16 formed of metal in a cylindrical shape is provided radially outside the holder 15.

  The fuel flowing from the inlet 24 is supplied to the fixed core 50, the adjusting pipe 51, the hole 543 of the gap forming member 54, the axial hole 37 of the needle 30, the radial hole 38, the first cylindrical member 21 and the needle 30. Between the nozzle portion 10 and the needle 30, that is, through the fuel passage 26, and is guided to the injection hole 13. When the fuel injection device 1 operates, the periphery of the movable core 40 is filled with fuel. Further, when the fuel injection device 1 operates, the fuel flows through the hole 42 of the movable core 40. Therefore, the movable core 40 can smoothly reciprocate in the axial direction inside the housing 20.

Next, the inner protrusion 60, the outer protrusion 70, the inner protrusion 80, and the outer protrusion 90 will be described in detail with reference to FIG.
In the present embodiment, the inner and outer diameters of the first tubular member 21, the second tubular member 22, and the third tubular member 23 are set to be the same among all members.

  The inner protruding portion 60 is made of a nonmagnetic material such as austenitic stainless steel, like the second cylindrical member 22. The inner protruding portion 60 projects substantially cylindrically from the end surface 221 of the second cylindrical member 22 on the third cylindrical member 23 side toward the third cylindrical member 23, and the end surface 601 is the second cylindrical member of the third cylindrical member 23. It is formed integrally with the second cylindrical member 22 so as to be connected to the end surface 231 on the 22 side. Here, the inner diameter of the inner projecting portion 60 is the same as the inner diameter of the second cylindrical member 22. The outer diameter of the inner protruding portion 60 is smaller than the outer diameter of the second cylindrical member 22.

  The outer protruding portion 70 is formed of a magnetic material such as a ferritic stainless steel, similarly to the third cylindrical member 23. The outer protruding portion 70 projects in a substantially cylindrical shape from the end surface 231 of the third cylindrical member 23 on the second cylindrical member 22 side toward the second cylindrical member 22, and the end surface 701 is the third cylindrical member of the second cylindrical member 22. It is formed integrally with the third tubular member 23 so as to be connected to the end face 221 on the 23 side. Here, the inner diameter of the outer protrusion 70 is the same as the outer diameter of the inner protrusion 60. Therefore, the inner wall of the outer projection 70 comes into contact with the outer wall of the inner projection 60 by surface contact. The outer diameter of the outer projection 70 is the same as the outer diameter of the third cylindrical member 23.

  The inner protruding portion 80 is made of a nonmagnetic material such as austenitic stainless steel, like the second cylindrical member 22. The inner protruding portion 80 projects in a substantially cylindrical shape from the end surface 222 of the second cylindrical member 22 on the first cylindrical member 21 side toward the first cylindrical member 21, and the end surface 801 is the second cylindrical member of the first cylindrical member 21. It is formed integrally with the second cylindrical member 22 so as to be connected to the end face 211 on the 22 side. Here, the inner diameter of the inner projection 80 is the same as the inner diameter of the second cylindrical member 22. The outer diameter of the inner projection 80 is smaller than the outer diameter of the second cylindrical member 22. In the present embodiment, the outer diameter of the inner protrusion 80 is the same as the outer diameter of the inner protrusion 60 and the inner diameter of the outer protrusion 70.

  The outer protruding portion 90 is made of a magnetic material such as ferrite stainless steel, for example, like the first cylindrical member 21. The outer projecting portion 90 projects in a substantially cylindrical shape from the end surface 211 of the first cylindrical member 21 on the side of the second cylindrical member 22 toward the second cylindrical member 22, and the end surface 901 is the first cylindrical member of the second cylindrical member 22. It is formed integrally with the first cylindrical member 21 so as to be connected to the end surface 222 on the 21 side. Here, the inner diameter of the outer protrusion 90 is the same as the outer diameter of the inner protrusion 80. Therefore, the inner wall of the outer protrusion 90 contacts the outer wall of the inner protrusion 80 by surface contact. The outer diameter of the outer protrusion 90 is the same as the outer diameter of the first tubular member 21.

  In the present embodiment, the connection portion between the second cylindrical member 22 and the outer protruding portion 70 is welded over the entire circumference in the circumferential direction. In addition, the connecting portion between the second cylindrical member 22 and the outer protruding portion 90 is welded over the entire circumference in the circumferential direction. Thereby, the fuel passage 26 inside the housing 20 is kept liquid-tight, and the first cylinder member 21, the second cylinder member 22, and the third cylinder member 23 can be prevented from being separated in the axial direction.

  In the present embodiment, the outer protrusion 70 integrated with the third cylinder member 23 is located radially outside the inner protrusion 60 integrated with the second cylindrical member 22, and the outer wall of the inner protrusion 60 is 70 is in contact with the inner wall. Therefore, even if the pressure of the fuel in the fuel passage 26 increases, the radial deformation of the inner protruding portion 60 is suppressed.

  Further, an outer protruding portion 90 integral with the first cylindrical member 21 is located radially outside the inner protruding portion 80 integral with the second cylindrical member 22, and an outer wall of the inner protruding portion 80 is an inner wall of the outer protruding portion 90. Is in contact with Therefore, even if the pressure of the fuel in the fuel passage 26 increases, the radial deformation of the inner protrusion 80 is suppressed.

As described above, (1) and (2) In the present embodiment, the housing 20 has the first tubular member 21, the second tubular member 22, the third tubular member 23, and the fuel passage 26.
The first cylinder member 21 is provided such that one end thereof is connected to a side of the nozzle cylinder 11 opposite to the nozzle bottom 12.
The second tubular member 22 is provided such that one end is located on the other end side of the first tubular member 21.
The third tubular member 23 is provided such that one end is located on the other end side of the second tubular member 22.
The fuel passage 26 is formed inside the first tubular member 21, the second tubular member 22, and the third tubular member 23 so as to guide fuel to the injection hole 13.

The inner protruding portion 60 is formed integrally with the second cylindrical member 22 so as to protrude cylindrically from an end surface 221 of the second cylindrical member 22 on the third cylindrical member 23 side and to be connected to the third cylindrical member 23.
The outer protruding portion 70 protrudes cylindrically from an end surface 231 of the third cylindrical member 23 on the side of the second cylindrical member 22 and is connected to the second cylindrical member 22 so that the inner wall contacts the outer wall of the inner protruding portion 60. 23 and are formed integrally.
The inner protruding portion 80 is formed integrally with the second cylindrical member 22 so as to protrude cylindrically from an end surface 222 of the second cylindrical member 22 on the first cylindrical member 21 side and to be connected to the first cylindrical member 21.
The outer projecting portion 90 projects in a tubular manner from the end surface 211 of the first tubular member 21 on the side of the second tubular member 22 and is connected to the second tubular member 22 so that the inner wall abuts on the outer wall of the inner projecting portion 80. 21 are formed integrally.

  In the present embodiment, the outer protrusion 70 integrated with the third cylinder member 23 is located radially outside the inner protrusion 60 integrated with the second cylindrical member 22, and the outer wall of the inner protrusion 60 is 70 is in contact with the inner wall. Further, an outer protruding portion 90 integral with the first cylindrical member 21 is located radially outside the inner protruding portion 80 integral with the second cylindrical member 22, and an outer wall of the inner protruding portion 80 is an inner wall of the outer protruding portion 90. Is in contact with Therefore, even if the pressure of the fuel in the fuel passage 26 increases, the radial deformation of the inner protrusion 60 and the inner protrusion 80 can be suppressed. Thereby, the connection position of the inner protrusion 60 with the third cylindrical member 23, the connection position of the outer protrusion 70 with the second cylindrical member 22, the connection position of the inner protrusion 80 with the first cylindrical member 21, and It is possible to suppress concentration of stress on the connection portion of the outer protrusion 90 with the second cylindrical member 22. As a result, it is possible to suppress the rupture of the connection point (weld point) and the generation of a gap at the connection point. Therefore, it is possible to prevent the fuel from leaking out of the housing 20 from the fuel passage 26 through the gap. Therefore, in the present embodiment, high-pressure fuel can be injected while fuel leakage from the fuel passage 26 to the outside of the housing 20 is suppressed.

(8) In the present embodiment, the movable core 40, the fixed core 50, the coil 57, and the spring 52 are provided.
The movable core 40 is provided so as to be able to reciprocate in the fuel passage 26 together with the needle 30.
The fixed core 50 is provided inside the housing 20 on the side opposite to the valve seat 14 of the movable core 40.
The coil 57 is provided outside the housing 20, and when energized, can draw the movable core 40 toward the fixed core 50 and move the needle 30 to the side opposite to the valve seat 14.
The spring 52 can bias the needle 30 and the movable core 40 toward the valve seat 14.
The first cylinder member 21 and the third cylinder member 23 are formed of a magnetic material.
The second cylindrical member 22 is formed of a non-magnetic material.

(9) In the present embodiment, the third cylindrical member 23 is formed integrally with the fixed core 50 so that the inner wall is connected to the outer wall of the fixed core 50. Thereby, the number of members can be reduced, and the deformation of the third cylindrical member 23 can be suppressed.
(10) In the present embodiment, the needle 30 has the contact surface 34 that can contact the contact surface 44 that is the surface of the movable core 40 on the fixed core 50 side.

  The movable core 40 is provided so as to be relatively movable with respect to the needle 30 so that the movable core 40 can abut on the contact surface 34 or be separated from the contact surface 34. As described above, by forming the needle 30 and the movable core 40 separately so as to be relatively movable, it is possible to increase the pressure of the injected fuel.

  (11) In the present embodiment, the gap forming member 54 capable of forming the gap C1 between the contact surface 34 and the movable core 40 is provided. Therefore, when the coil 57 is energized, the movable core 40 can be accelerated in the gap C <b> 1 to collide with the contact surface 34 of the flange 33 of the needle 30. Thus, even when the pressure in the fuel passage 26 is relatively high, the needle 30 can be opened without increasing the power supplied to the coil 57. Therefore, the pressure of the injected fuel can be increased with low power consumption.

(2nd Embodiment)
FIG. 3 shows a part of a fuel injection device according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in the shapes of the inner protrusion 60 and the inner protrusion 80.
In the second embodiment, the inner protruding portion 60 has a chamfered inner corner at the end on the third cylindrical member 23 side. The inner protruding portion 80 has a chamfered corner at the end on the first cylindrical member 21 side.

  The outer diameter of the inner protrusion 60 and the inner diameter of the outer protrusion 70 are set larger than the outer diameter of the inner protrusion 60 and the inner diameter of the outer protrusion 70 in the first embodiment. The outer diameter of the inner protrusion 80 and the inner diameter of the outer protrusion 90 are set larger than the outer diameter of the inner protrusion 80 and the inner diameter of the outer protrusion 90 in the first embodiment.

As described above, (3) In the present embodiment, the inner protruding portion 60 and the inner protruding portion 80 are formed integrally with the second cylindrical member 22. The inner protruding portion 60 has a chamfered inner corner at the end on the third cylindrical member 23 side. The inner protruding portion 80 has a chamfered corner at the end on the first cylindrical member 21 side. Thereby, the thickness (difference between the outer diameter and the inner diameter) of the end portions of the inner protruding portions 60 and 80 on the second cylindrical member 22 side can be increased. Therefore, even if the pressure of the fuel in the fuel passage 26 is increased, it is possible to suppress the radial deformation of the inner protruding portion 60 and the inner protruding portion 80, particularly the ends on the second cylindrical member 22 side.
Therefore, in the present embodiment, similarly to the first embodiment, high-pressure fuel can be injected while fuel leakage from the fuel passage 26 to the outside of the housing 20 is suppressed.

(Third embodiment)
FIG. 4 shows a part of a fuel injection device according to a third embodiment of the present invention. The third embodiment is different from the first embodiment in the shapes of the inner protrusion and the outer protrusion.

  In the third embodiment, the inner protruding portion 61 protrudes in a substantially cylindrical shape from the end surface 221 of the second cylindrical member 22 on the third cylindrical member 23 side toward the third cylindrical member 23, and the end 611 is formed of the third cylindrical member 23. The member 23 is formed integrally with the second cylinder member 22 so as to be connected to the end surface 231 on the second cylinder member 22 side. Here, the inner diameter of the inner protruding portion 61 is the same as the inner diameter of the second cylindrical member 22. Further, the inner protruding portion 61 is formed in a tapered shape so that the outer wall approaches the axis as going from the other side to the one side in the axial direction.

  The outer protruding portion 71 projects substantially cylindrically from the end surface 231 of the third cylinder member 23 on the second cylinder member 22 side toward the second cylinder member 22, and the end surface 711 is the third cylinder member of the second cylinder member 22. It is formed integrally with the third tubular member 23 so as to be connected to the end face 221 on the 23 side. Here, the outer protruding portion 71 is formed in a tapered shape so that the inner wall approaches the axis as going from the other side to the one side in the axial direction. Therefore, the inner wall of the outer protrusion 71 abuts on the outer wall of the inner protrusion 61 by surface contact. The outer diameter of the outer protrusion 71 is the same as the outer diameter of the third cylindrical member 23.

  The inner protruding portion 81 protrudes in a substantially cylindrical shape from the end surface 222 of the second cylinder member 22 on the first cylinder member 21 side toward the first cylinder member 21, and the end 811 is the second cylinder member of the first cylinder member 21. It is formed integrally with the second tubular member 22 so as to be connected to the end surface 211 on the member 22 side. Here, the inner diameter of the inner projection 80 is the same as the inner diameter of the second cylindrical member 22. Further, the inner protruding portion 81 is formed in a tapered shape such that the outer wall approaches the axis as going from one side to the other side in the axial direction.

  The outer protruding portion 91 projects substantially cylindrically from the end surface 211 of the first cylinder member 21 on the second cylinder member 22 side toward the second cylinder member 22, and the end surface 911 is the first cylinder member of the second cylinder member 22. It is formed integrally with the first cylindrical member 21 so as to be connected to the end surface 222 on the 21 side. Here, the outer protruding portion 91 is formed in a tapered shape such that the inner wall approaches the axis as going from one side to the other side in the axial direction. Therefore, the inner wall of the outer protrusion 91 abuts on the outer wall of the inner protrusion 81 by surface contact. The outer diameter of the outer protrusion 91 is the same as the outer diameter of the first tubular member 21.

  As described above, (4) In the present embodiment, the inner protruding portion 61 is formed such that the entire outer wall in the axial direction approaches the axis from the other side in the axial direction to the one side. Further, the inner protruding portion 81 is formed such that the entire outer wall in the axial direction approaches the axis from one side in the axial direction to the other side.

The outer protruding portion 71 is formed such that all of the inner wall in the axial direction approaches the axis from the other side in the axial direction toward one side. Further, the outer protruding portion 91 is formed such that the entire inner wall in the axial direction approaches the axis from one side in the axial direction to the other side.
Also in the present embodiment, similarly to the first embodiment, high-pressure fuel can be injected while fuel leakage from the fuel passage 26 to the outside of the housing 20 is suppressed.

(Fourth embodiment)
FIG. 5 shows a part of a fuel injection device according to a fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in the number, arrangement, and the like of the inner protruding portion and the outer protruding portion.

  In the fourth embodiment, the inner projecting portion 62 projects substantially cylindrically from the end surface 231 of the third cylindrical member 23 on the second cylindrical member 22 side toward the second cylindrical member 22, and the end surface 621 is formed of the second cylindrical member 23. 22 is formed integrally with the third cylindrical member 23 so as to be connected to the end surface 221 on the third cylindrical member 23 side. Here, the inner diameter of the inner protrusion 62 is the same as the inner diameter of the second tubular member 22. That is, the inner protruding portion 62 is formed integrally with the fixed core 50 so that the inner wall is connected to the outer wall of the fixed core 50. The outer diameter of the inner protruding portion 62 is smaller than the outer diameter of the third cylindrical member 23.

  The outer projecting portion 72 projects substantially cylindrically from the end surface 221 of the second cylindrical member 22 on the third cylindrical member 23 side toward the third cylindrical member 23, and the end surface 721 is the second cylindrical member of the third cylindrical member 23. It is formed integrally with the second cylindrical member 22 so as to be connected to the end surface 231 on the 22 side. Here, the inner diameter of the outer protrusion 72 is the same as the outer diameter of the inner protrusion 62. Therefore, the inner wall of the outer protrusion 72 abuts on the outer wall of the inner protrusion 62 by surface contact. The outer diameter of the outer protrusion 72 is smaller than the outer diameter of the second cylindrical member 22.

  The inner protruding portion 82 projects substantially cylindrically from the end surface 211 of the first cylinder member 21 on the second cylinder member 22 side toward the second cylinder member 22, and the end surface 821 is the first cylinder member of the second cylinder member 22. It is formed integrally with the first cylindrical member 21 so as to be connected to the end surface 222 on the 21 side. Here, the inner diameter of the inner protruding portion 82 is the same as the inner diameter of the first cylindrical member 21. The outer diameter of the inner protruding portion 82 is smaller than the outer diameter of the first cylindrical member 21. In the present embodiment, the outer diameter of the inner protrusion 82 is the same as the outer diameter of the inner protrusion 62 and the inner diameter of the outer protrusion 72.

  The outer protruding portion 92 protrudes from the end surface 222 of the second cylinder member 22 on the first cylinder member 21 side toward the first cylinder member 21 in a substantially cylindrical shape, and the end surface 921 is the second cylinder member of the first cylinder member 21. It is formed integrally with the second cylindrical member 22 so as to be connected to the end face 211 on the 22 side. Here, the inner diameter of the outer protrusion 92 is the same as the outer diameter of the inner protrusion 82. Therefore, the inner wall of the outer protrusion 92 contacts the outer wall of the inner protrusion 82 by surface contact. The outer diameter of the outer protrusion 92 is smaller than the outer diameter of the second cylindrical member 22.

  The inner protruding portion 63 projects in a substantially cylindrical shape from the end surface 221 of the second cylindrical member 22 on the third cylindrical member 23 side toward the third cylindrical member 23, and the end surface 631 is the second cylindrical member of the third cylindrical member 23. It is formed integrally with the second cylindrical member 22 so as to be connected to the end surface 231 on the 22 side. Here, the inner diameter of the inner protrusion 63 is the same as the outer diameter of the outer protrusion 72. Therefore, the inner protrusion 63 is formed integrally with the outer protrusion 72 so that the inner wall is connected to the outer wall of the outer protrusion 72. The outer diameter of the inner protruding portion 63 is smaller than the outer diameter of the second cylindrical member 22.

  The outer projecting portion 73 projects substantially cylindrically from the end surface 231 of the third cylindrical member 23 on the second cylindrical member 22 side toward the second cylindrical member 22, and the end surface 731 is the third cylindrical member of the second cylindrical member 22. It is formed integrally with the third tubular member 23 so as to be connected to the end face 221 on the 23 side. Here, the inner diameter of the outer protrusion 73 is the same as the outer diameter of the inner protrusion 63. Therefore, the inner wall of the outer protrusion 73 contacts the outer wall of the inner protrusion 63 by surface contact. The outer diameter of the outer projection 73 is the same as the outer diameter of the third cylindrical member 23.

  The inner protruding portion 83 protrudes from the end surface 222 of the second cylinder member 22 on the first cylinder member 21 side toward the first cylinder member 21 in a substantially cylindrical shape, and the end surface 831 is the second cylinder member of the first cylinder member 21. It is formed integrally with the second cylindrical member 22 so as to be connected to the end face 211 on the 22 side. Here, the inner diameter of the inner protrusion 83 is the same as the outer diameter of the outer protrusion 92. Therefore, the inner protrusion 83 is formed integrally with the outer protrusion 92 so that the inner wall is connected to the outer wall of the outer protrusion 92. The outer diameter of the inner protruding portion 83 is smaller than the outer diameter of the second cylindrical member 22.

  The outer protruding portion 93 projects substantially cylindrically from the end surface 211 of the first cylinder member 21 on the side of the second cylinder member 22 toward the second cylinder member 22, and the end surface 931 is formed of the first cylinder member of the second cylinder member 22. It is formed integrally with the first cylindrical member 21 so as to be connected to the end surface 222 on the 21 side. Here, the inner diameter of the outer projection 93 is the same as the outer diameter of the inner projection 83. Therefore, the inner wall of the outer protruding portion 93 comes into contact with the outer wall of the inner protruding portion 83 by surface contact. The outer diameter of the outer protrusion 93 is the same as the outer diameter of the first tubular member 21.

As described above, in the present embodiment, the inner protruding portion 62, the outer protruding portion 72, the inner protruding portion 63, and the outer protruding portion 73 are arranged in the radial direction of the second cylindrical member 22, that is, arranged on a concentric circle. The outer wall and the inner wall are in contact with or connected to each other. Further, the inner protruding portion 82, the outer protruding portion 92, the inner protruding portion 83, and the outer protruding portion 93 are arranged in the radial direction of the second cylindrical member 22, that is, arranged concentrically, and the outer wall and the inner wall abut each other. Or are connected. Thus, even if the pressure of the fuel in the fuel passage 26 increases, the inner protrusion 62, the outer protrusion 72, the inner protrusion 63, the outer protrusion 73, the inner protrusion 82, the outer protrusion 92, the inner protrusion 83, radial deformation of the outer projection 93 can be suppressed.
Therefore, in the present embodiment, similarly to the first embodiment, high-pressure fuel can be injected while fuel leakage from the fuel passage 26 to the outside of the housing 20 is suppressed.

(Fifth embodiment)
FIG. 6 shows a part of a fuel injection device according to a fifth embodiment of the present invention. The fourth embodiment is different from the first embodiment in the arrangement and the like of the inner protrusion and the outer protrusion.

  In the fifth embodiment, the inner projecting portion 64 projects substantially cylindrically from the end surface 231 of the third cylindrical member 23 on the second cylindrical member 22 side toward the second cylindrical member 22, and the end surface 641 is formed by the second cylindrical member 22. 22 is formed integrally with the third cylindrical member 23 so as to be connected to the end surface 221 on the third cylindrical member 23 side. Here, the inner diameter of the inner protruding portion 64 is the same as the inner diameter of the second cylindrical member 22. That is, the inner protruding portion 64 is formed integrally with the fixed core 50 so that the inner wall is connected to the outer wall of the fixed core 50. Further, the outer diameter of the inner protruding portion 64 is smaller than the outer diameter of the third cylindrical member 23.

  The outer protruding portion 74 projects substantially cylindrically from the end surface 221 of the second cylinder member 22 on the third cylinder member 23 side toward the third cylinder member 23, and the end surface 741 is the second cylinder member of the third cylinder member 23. It is formed integrally with the second cylindrical member 22 so as to be connected to the end surface 231 on the 22 side. Here, the inner diameter of the outer protrusion 74 is the same as the outer diameter of the inner protrusion 64. Therefore, the inner wall of the outer protrusion 74 contacts the outer wall of the inner protrusion 64 by surface contact. The outer diameter of the outer protrusion 74 is the same as the outer diameter of the second cylindrical member 22.

  The inner protruding portion 84 projects in a substantially cylindrical shape from the end surface 211 of the first cylinder member 21 on the second cylinder member 22 side toward the second cylinder member 22, and the end surface 841 is the first cylinder member of the second cylinder member 22. It is formed integrally with the first cylindrical member 21 so as to be connected to the end surface 222 on the 21 side. Here, the inner diameter of the inner projection 84 is the same as the inner diameter of the first tubular member 21. The outer diameter of the inner protrusion 84 is smaller than the outer diameter of the first cylindrical member 21. In the present embodiment, the outer diameter of the inner protrusion 84 is the same as the outer diameter of the inner protrusion 64 and the inner diameter of the outer protrusion 74.

The outer protruding portion 94 protrudes in a substantially cylindrical shape from the end surface 222 of the second cylindrical member 22 on the first cylindrical member 21 side toward the first cylindrical member 21, and the end surface 941 is the second cylindrical member of the first cylindrical member 21. It is formed integrally with the second cylindrical member 22 so as to be connected to the end face 211 on the 22 side. Here, the inner diameter of the outer protrusion 94 is the same as the outer diameter of the inner protrusion 84. Therefore, the inner wall of the outer protrusion 94 contacts the outer wall of the inner protrusion 84 by surface contact. The outer diameter of the outer protrusion 94 is the same as the outer diameter of the second cylindrical member 22.
In the present embodiment, the connection portion between the third cylindrical member 23 and the outer protruding portion 74 is welded over the entire circumference in the circumferential direction. In addition, the connecting portion between the first cylindrical member 21 and the outer protruding portion 94 is welded over the entire circumference in the circumferential direction.

As described above, (1) and (2) in the present embodiment, the inner protruding portion 64 protrudes cylindrically from the end surface 231 of the third cylindrical member 23 on the side of the second cylindrical member 22, and is formed on the second cylindrical member 22. It is formed integrally with the third cylindrical member 23 so as to be connected.
The outer protruding portion 74 protrudes in a cylindrical shape from the end surface 221 of the second cylindrical member 22 on the third cylindrical member 23 side, is connected to the third cylindrical member 23, and the inner wall is in contact with the outer wall of the inner protruding portion 64. 22 are formed integrally.
The inner protruding portion 84 is formed integrally with the first cylindrical member 21 so as to protrude cylindrically from the end surface 211 of the first cylindrical member 21 on the second cylindrical member 22 side and to be connected to the second cylindrical member 22.
The outer protruding portion 94 protrudes cylindrically from the end surface 222 of the second cylindrical member 22 on the first cylindrical member 21 side and is connected to the first cylindrical member 21 so that the inner wall abuts on the outer wall of the inner protruding portion 84. 22 are formed integrally.
Also in the present embodiment, similarly to the first embodiment, high-pressure fuel can be injected while fuel leakage from the fuel passage 26 to the outside of the housing 20 is suppressed.

(Sixth embodiment)
FIG. 7 shows a part of a fuel injection device according to a sixth embodiment of the present invention. The sixth embodiment is different from the first embodiment in the arrangement and the like of the inner protrusion and the outer protrusion.

The sixth embodiment includes the inner protrusion 60 and the outer protrusion 70 shown in the first embodiment, and the inner protrusion 84 and the outer protrusion 94 shown in the fifth embodiment. That is, the sixth embodiment is a mode in which the first embodiment and the fifth embodiment are combined.
Also in the present embodiment, similarly to the first embodiment, high-pressure fuel can be injected while fuel leakage from the fuel passage 26 to the outside of the housing 20 is suppressed.

(Seventh embodiment)
FIG. 8 shows a part of a fuel injection device according to a seventh embodiment of the present invention. The seventh embodiment differs from the first embodiment in the shapes and the like of the inner protrusion 60, the outer protrusion 70, the inner protrusion 80, and the outer protrusion 90.

  In the seventh embodiment, the inner protruding portion 60 includes the inner large-diameter portion 602 and the inner small-diameter portion 603 formed on the inner cylindrical portion 602 on the second cylindrical member 22 side and having an outer diameter smaller than the inner large-diameter portion 602. Have. The inner protruding portion 60 is formed in a tapered shape such that outer walls of the inner large-diameter portion 602 and the inner small-diameter portion 603 approach the axis from one side in the axial direction to the other side.

  The outer protruding portion 70 has an outer large-diameter portion 702 and an outer small-diameter portion 703 formed on the second cylindrical member 22 side of the outer large-diameter portion 702 and having an inner diameter smaller than the outer large-diameter portion 702. The outer protruding portion 70 is formed in a tapered shape such that the inner walls of the outer large-diameter portion 702 and the outer small-diameter portion 703 approach the axis from one side in the axial direction to the other side. Therefore, the outer large-diameter portion 702 and the outer small-diameter portion 703 of the outer protruding portion 70 come into contact with the outer wall of the inner large-diameter portion 602 and the inner small-diameter portion 603 of the inner protruding portion 60 by surface contact.

  The inner protruding portion 80 includes an inner large-diameter portion 802 and an inner small-diameter portion 803 formed on the inner large-diameter portion 802 on the second cylindrical member 22 side and having an outer diameter smaller than the inner large-diameter portion 802. The inner protruding portion 80 is formed in a tapered shape such that the outer walls of the inner large-diameter portion 802 and the inner small-diameter portion 803 approach the axis from the other side to the one side in the axial direction.

  The outer protruding portion 90 has an outer large-diameter portion 902 and an outer small-diameter portion 903 formed on the second cylindrical member 22 side of the outer large-diameter portion 902 and having an inner diameter smaller than the outer large-diameter portion 902. The outer protruding portion 90 is formed in a tapered shape such that the inner walls of the outer large-diameter portion 902 and the outer small-diameter portion 903 approach the axis from the other side to the one side in the axial direction. Therefore, the inner wall of the outer large-diameter portion 902 and the inner wall of the outer small-diameter portion 903 of the outer protruding portion 90 come into contact with the outer walls of the inner large-diameter portion 802 and the inner small-diameter portion 803 of the inner protruding portion 80 by surface contact.

The inner large-diameter portion 602 of the inner protruding portion 60 and the outer small-diameter portion 703 of the outer protruding portion 70 are formed so as to overlap in the axial direction. The inner large-diameter portion 802 of the inner protruding portion 80 and the outer small-diameter portion 903 of the outer protruding portion 90 are formed so as to overlap in the axial direction.
In the present embodiment, the third tubular member 23 is formed separately from the fixed core 50.

  In the present embodiment, when the housing 20 is formed by assembling the first tubular member 21, the second tubular member 22, and the third tubular member 23, for example, the second tubular member 22 is formed together with the inner protruding portion 60 and the inner protruding portion 80. Each member is connected in a state where the outer diameter is reduced by cooling and the first cylindrical member 21 and the third cylindrical member 23 are heated together with the outer protrusion 70 and the outer protrusion 90 to increase the inner diameter. As a result, the inner protruding portion 60 corresponds to the third cylindrical member 23, the outer protruding portion 70 corresponds to the second cylindrical member 22, the inner protruding portion 80 corresponds to the first cylindrical member 21, and the outer protruding portion 90 corresponds to the second cylindrical member 22. The members can be connected relatively easily to form the housing 20 for connection. When the first tubular member 21, the second tubular member 22, and the third tubular member 23 assembled by the above method return to normal temperature, the outer wall of the inner protruding portion 60 and the inner wall of the outer protruding portion 70 The outer wall and the inner wall of the outer protrusion 90 are brought into contact with each other by surface contact. Thereafter, the fixed core 50 may be inserted inside the third tubular member 23 and the second tubular member 22.

  As described above, (4) In the present embodiment, the inner protruding portion 60 is formed so that the entire axial direction of the outer wall approaches the axis from one side in the axial direction to the other side. The inner protruding portion 80 is formed so that the entire outer wall in the axial direction approaches the axis from the other side in the axial direction toward one side.

  The outer protruding portion 70 is formed so that the whole of the inner wall in the axial direction approaches the axis from one side in the axial direction to the other side. Further, the outer protrusion 90 is formed so that the entire inner wall in the axial direction approaches the axis from the other side in the axial direction to one side.

  (5) In the present embodiment, the inner protruding portion 60 is formed on the inner large-diameter portion 602 and on the second cylindrical member 22 side of the inner large-diameter portion 602 and has an outer diameter smaller than the inner large-diameter portion 602. It has a small diameter portion 603. The outer protruding portion 70 has an outer large-diameter portion 702 and an outer small-diameter portion 703 formed on the second cylindrical member 22 side of the outer large-diameter portion 702 and having an inner diameter smaller than the outer large-diameter portion 702. The inner protruding portion 80 includes an inner large-diameter portion 802 and an inner small-diameter portion 803 formed on the inner large-diameter portion 802 on the second cylindrical member 22 side and having an outer diameter smaller than the inner large-diameter portion 802. The outer protruding portion 90 has an outer large-diameter portion 902 and an outer small-diameter portion 903 formed on the second cylindrical member 22 side of the outer large-diameter portion 902 and having an inner diameter smaller than the outer large-diameter portion 902.

  The inner large-diameter portion 602 of the inner protruding portion 60 and the outer small-diameter portion 703 of the outer protruding portion 70 are formed so as to overlap in the axial direction. The inner large-diameter portion 802 of the inner protruding portion 80 and the outer small-diameter portion 903 of the outer protruding portion 90 are formed so as to overlap in the axial direction. Therefore, it is possible to restrict the axial separation of the second tubular member 22 and the third tubular member 23 and the second tubular member 22 and the first tubular member 21. Therefore, even if the pressure in the fuel passage 26 further increases, the leakage of fuel from the fuel passage 26 to the outside of the housing 20 and the damage of the housing 20 can be suppressed.

(Eighth embodiment)
FIG. 9 shows a part of a fuel injection device according to an eighth embodiment of the present invention. The eighth embodiment is different from the seventh embodiment in the shapes and the like of the inner protrusion 60, the outer protrusion 70, the inner protrusion 80, and the outer protrusion 90.

  In the eighth embodiment, the outer diameters of the inner large diameter portion 602 and the inner small diameter portion 603 of the inner projection 60, the inner diameters of the outer large diameter portion 702 and the outer small diameter portion 703 of the outer projection 70, and the inner diameter of the inner projection 80 are large. The outer diameter of the diameter part 802 and the inner small diameter part 803, and the inner diameter of the outer large diameter part 902 and the outer small diameter part 903 of the outer protrusion 90 are constant in the axial direction. Therefore, an inner locking surface 604 is formed between the inner large-diameter portion 602 and the inner small-diameter portion 603 of the inner protruding portion 60 so as to annularly expand radially outward of the inner protruding portion 60. An outer locking surface 704 is formed between the outer large-diameter portion 702 and the outer small-diameter portion 703 of the outer protruding portion 70 so as to annularly expand radially inward of the outer protruding portion 70. Here, the outer locking surface 704 can contact the inner locking surface 604. Therefore, the inner locking surface 604 and the outer locking surface 704 can be locked to each other. Thereby, the relative movement in the axial direction between the second cylindrical member 22 and the third cylindrical member 23 is restricted.

An inner locking surface 804 is formed between the inner large-diameter portion 802 and the inner small-diameter portion 803 of the inner protruding portion 80 so as to extend annularly outward in the radial direction of the inner protruding portion 80. An outer locking surface 904 is formed between the outer large-diameter portion 902 and the outer small-diameter portion 903 of the outer protruding portion 90 so as to be annularly expanded radially inward of the outer protruding portion 90. Here, the outer locking surface 904 can contact the inner locking surface 804. Therefore, the inner locking surface 804 and the outer locking surface 904 can be locked to each other. Thereby, the relative movement in the axial direction between the second cylindrical member 22 and the first cylindrical member 21 is restricted.
When assembling the first tubular member 21, the second tubular member 22, and the third tubular member 23 to form the housing 20, a method similar to the method described in the seventh embodiment may be employed.

  As described above, (7) In the present embodiment, the inner protruding portion 60 has the inner locking surface 604, and the outer protruding portion 70 has the outer locking surface 704 that can abut the inner locking surface 604. are doing. The inner projection 80 has an inner locking surface 804, and the outer projection 90 has an outer locking surface 904 capable of locking the inner locking surface 804. Therefore, it is possible to reliably restrict the axial separation of the second tubular member 22 and the third tubular member 23 and the second tubular member 22 and the first tubular member 21. Therefore, even if the pressure in the fuel passage 26 further increases, leakage of fuel from the fuel passage 26 to the outside of the housing 20 and damage to the housing 20 can be effectively suppressed.

(Ninth embodiment)
FIG. 10 shows a part of a fuel injection device according to a ninth embodiment of the present invention. The ninth embodiment differs from the eighth embodiment in the shapes and the like of the inner protrusion 60, the outer protrusion 70, the inner protrusion 80, and the outer protrusion 90.

  In the ninth embodiment, the inner protruding portion 60 is formed in a tapered shape so that the outer wall of the inner large-diameter portion 602 approaches the axis from the other side to the one side in the axial direction. The outer protruding portion 70 is formed in a tapered shape so that the inner wall of the outer small diameter portion 703 approaches the axis from the other side to the one side in the axial direction. For this reason, when the second cylindrical member 22 and the third cylindrical member 23 are moved toward each other in the axial direction when the second cylindrical member 22 and the third cylindrical member 23 are assembled, the inner large-diameter portion of the inner protruding portion 60 is formed. While the outer wall 602 and the inner wall of the outer small diameter portion 703 of the outer projection 70 slide, the inner projection 60 and the outer projection 70 elastically deform in the radial direction. When the end surface 601 of the inner protruding portion 60 comes into contact with the end surface 231 of the third tubular member 23, the inner locking surface 604 and the outer locking surface 704 come into contact with each other (see FIG. 10).

  The inner protruding portion 80 is formed in a tapered shape so that the outer wall of the inner large-diameter portion 802 approaches the axis from one side in the axial direction to the other side. The outer protruding portion 90 is formed in a tapered shape so that the inner wall of the outer small diameter portion 903 approaches the axis from one side in the axial direction to the other side. Therefore, when assembling the second cylindrical member 22 and the first cylindrical member 21, when the second cylindrical member 22 and the first cylindrical member 21 are moved closer to each other in the axial direction, the inner large-diameter portion of the inner projecting portion 80 is formed. While the outer wall 802 and the inner wall of the outer small diameter portion 903 of the outer projection 90 slide, the inner projection 80 and the outer projection 90 elastically deform in the radial direction. When the end surface 801 of the inner protruding portion 80 comes into contact with the end surface 211 of the first cylindrical member 21, the inner locking surface 804 and the outer locking surface 904 are in contact with each other (see FIG. 10).

  As described above, (7) in the present embodiment, the inner protrusion 60 has the inner locking surface 604, the outer protrusion 70 has the outer locking surface 704, and the inner protrusion 80 has the inner locking. The outer projection 90 has an outer locking surface 904. Therefore, similarly to the eighth embodiment, the axial separation of the second cylindrical member 22 and the third cylindrical member 23 and the second cylindrical member 22 and the first cylindrical member 21 can be surely restricted. .

  In the present embodiment, the outer wall of the inner large-diameter portion 602 of the inner protruding portion 60, the inner wall of the outer small-diameter portion 703 of the outer protruding portion 70, the outer wall of the inner large-diameter portion 802 of the inner protruding portion 80, and the outer protruding portion 90 The inner wall of the outer small diameter portion 903 is formed in a tapered shape. Therefore, when assembling the first tubular member 21, the second tubular member 22, and the third tubular member 23 to form the housing 20, it is not necessary to cool or heat each member as in the seventh and eighth embodiments. The members can be easily assembled.

(Tenth embodiment)
FIG. 11 shows a part of a fuel injection device according to a tenth embodiment of the present invention. The tenth embodiment is different from the fifth embodiment in the shape and the like of the inner protrusion 60, the outer protrusion 70, the inner protrusion 80, and the outer protrusion 90.

  In the tenth embodiment, the inner protruding portion 64 has an inner small-diameter portion 643 and an inner large-diameter portion 642 formed on the second cylindrical member 22 side of the inner small-diameter portion 643 and having an outer diameter larger than the inner small-diameter portion 643. ing. The outer protruding portion 74 has an outer small diameter portion 743 and an outer large diameter portion 742 formed on the second cylindrical member 22 side of the outer small diameter portion 743 and having an inner diameter larger than the outer small diameter portion 743.

  An inner locking surface 644 is formed between the inner large-diameter portion 642 and the inner small-diameter portion 643 of the inner protruding portion 64 so as to extend annularly outward in the radial direction of the inner protruding portion 64. An outer locking surface 704 is formed between the outer large-diameter portion 742 and the outer small-diameter portion 743 of the outer protruding portion 74 so as to annularly expand radially inward of the outer protruding portion 74. Here, the outer locking surface 704 can contact the inner locking surface 604.

  The inner protruding portion 84 has an inner small-diameter portion 843 and an inner large-diameter portion 842 formed on the inner small-diameter portion 843 on the second cylindrical member 22 side and having an outer diameter larger than the inner small-diameter portion 843. The outer protruding portion 94 has an outer small-diameter portion 943 and an outer large-diameter portion 942 formed on the second cylindrical member 22 side of the outer small-diameter portion 943 and having an inner diameter larger than the outer small-diameter portion 943.

An inner locking surface 844 is formed between the inner large-diameter portion 842 and the inner small-diameter portion 843 of the inner protruding portion 84 so as to extend annularly outward in the radial direction of the inner protruding portion 84. An outer locking surface 944 is formed between the outer large-diameter portion 942 and the outer small-diameter portion 943 of the outer protruding portion 94 so as to annularly expand radially inward of the outer protruding portion 94. Here, the outer locking surface 944 can contact the inner locking surface 844.
When assembling the first tubular member 21, the second tubular member 22, and the third tubular member 23 to form the housing 20, a method similar to the method described in the seventh embodiment may be employed.

  As described above, (7) in the present embodiment, the inner protruding portion 64 has the inner locking surface 644, and the outer protruding portion 74 has the outer locking surface 744 that can abut the inner locking surface 644. are doing. The inner projection 84 has an inner locking surface 844, and the outer projection 94 has an outer locking surface 944 that can abut the inner locking surface 844. Therefore, it is possible to reliably restrict the axial separation of the second tubular member 22 and the third tubular member 23 and the second tubular member 22 and the first tubular member 21. Therefore, even if the pressure in the fuel passage 26 further increases, leakage of fuel from the fuel passage 26 to the outside of the housing 20 and damage to the housing 20 can be effectively suppressed.

(Other embodiments)
In the above-described embodiment, an example has been described in which the inner protruding portion and the outer protruding portion are provided at both ends of the second cylindrical member 22 on the third cylindrical member 23 side and the first cylindrical member 21 side. On the other hand, in another embodiment of the present invention, the inner protruding portion and the outer protruding portion may be provided on either the third cylindrical member 23 side or the first cylindrical member 21 side of the second cylindrical member 22. .

  In the above-described embodiment, various forms of the inner protruding portion and the outer protruding portion have been described. In another embodiment of the present invention, any combination of the inside protrusion and the outside protrusion in the above embodiment may be used as long as there is no obstructive factor.

  Further, in the above-described embodiment, the configuration in which the gap forming member capable of forming a gap between the flange portion of the needle and the movable core is provided, and the movable core is caused to collide with the flange portion while being accelerated by the gap. In another embodiment of the present invention, the gap forming member may not be provided. In this case, a configuration can be considered in which the end of the valve seat-side urging member (spring 52) abuts on the needle (flange), and the valve seat-side urging member urges the needle toward the valve seat.

  In the above-described embodiment, an example has been described in which the movable core is provided so as to be relatively movable with respect to the needle. On the other hand, in another embodiment of the present invention, the movable core may be provided so as not to move relative to the needle. Further, the movable core may be formed integrally with the needle so as not to move relative to the needle.

The present invention is not limited to a direct injection type gasoline engine, and may be applied to, for example, a port injection type gasoline engine or a diesel engine.
As described above, the present invention is not limited to the above embodiment, and can be implemented in various forms without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Fuel injection device, 10 nozzle part, 11 nozzle cylinder part, 12 nozzle bottom part, 13 injection hole, 14 valve seat, 20 housing, 21 first cylinder member, 22 second cylinder member, 23 third cylinder member, 26 fuel passage , 30 Needle, 60, 61, 62, 63, 64, 80, 81, 82, 83, 84 Inside Projection, 70, 71, 72, 73, 74, 90, 91, 92, 93, 94 Outside Projection

Claims (11)

A cylindrical nozzle tube portion (11), a nozzle bottom portion (12) closing one end of the nozzle tube portion, and a surface of the nozzle bottom portion on the side of the nozzle tube portion connected to a surface on the opposite side of the nozzle tube portion; A nozzle portion (10) having an injection hole (13) through which fuel is injected, and a valve seat (14) formed annularly around the injection hole on the side of the nozzle cylinder at the bottom of the nozzle;
A first cylinder member (21) provided with one end connected to the side opposite to the nozzle bottom of the nozzle cylinder portion, and a second cylinder member (21) provided with one end located at the other end side of the first cylinder member ( 22), a third tubular member (23) provided with one end located on the other end side of the second tubular member, and the first tubular member, the second tubular member and the third tubular member so as to guide fuel to the injection hole. A housing (20) having a fuel passage (26) formed inside the third cylinder member;
A needle (30) that is provided so as to be able to reciprocate in the fuel passage and that opens and closes the injection hole when one end is separated from the valve seat or abuts on the valve seat;
The end surface (221) of the second cylindrical member or the end surface of the second cylindrical member, which is the end surface of one of the second cylindrical member and the third cylindrical member (22, 23) on the side of the third cylindrical member. An inner side integrally formed with the second cylindrical member or the third cylindrical member so as to protrude cylindrically from an end surface (231) of the third cylindrical member and to be connected to the third cylindrical member or the second cylindrical member. Projecting parts (60, 61, 62, 63, 64);
The end surface (231) of the third cylindrical member or the end surface of the third cylindrical member that is the end surface of the other of the second cylindrical member or the third cylindrical member (23, 22) on the side of the second cylindrical member. The third cylindrical member or the third cylindrical member or the third cylindrical member is configured to protrude cylindrically from an end surface (221) of the second cylindrical member and to be connected to the second cylindrical member or the third cylindrical member so that an inner wall abuts on an outer wall of the inner protruding portion. Outer projections (70, 71, 72, 73, 74) formed integrally with the second cylindrical member,
An outer protruding end surface (701, 711, 731, 741), which is an end surface of the outer protruding portion, is in contact with an end surface (221) of the second cylindrical member or an end surface (231) of the third cylindrical member;
The end surface (601, 631, 641) or end (611) of the inner protruding portion and the outer protruding end surface are formed at positions shifted in the axial direction,
The housing has a welding portion for welding and fixing the outer protruding end surface and the end surface (221) of the second cylindrical member or the end surface (231) of the third cylindrical member,
The fuel injection device (1), wherein a length of the welded portion in a radial direction of the second cylindrical member is longer than at least the outer protruding end surface. A cylindrical nozzle tube portion (11), a nozzle bottom portion (12) closing one end of the nozzle tube portion, and a surface of the nozzle bottom portion on the side of the nozzle tube portion connected to a surface on the opposite side of the nozzle tube portion; A nozzle portion (10) having an injection hole (13) through which fuel is injected, and a valve seat (14) formed annularly around the injection hole on the side of the nozzle cylinder at the bottom of the nozzle;
A first cylinder member (21) provided with one end connected to the side opposite to the nozzle bottom of the nozzle cylinder portion, and a second cylinder member (21) provided with one end located at the other end side of the first cylinder member ( 22), a third tubular member (23) provided with one end located on the other end side of the second tubular member, and the first tubular member, the second tubular member and the third tubular member so as to guide fuel to the injection hole. A housing (20) having a fuel passage (26) formed inside the third cylinder member;
A needle (20) that is provided so as to be able to reciprocate in the fuel passage, and that opens and closes the injection hole when one end is separated from the valve seat or abuts on the valve seat;
The end surface (222) of the second cylinder member or the end surface of the second cylinder member, which is the end surface of one of the second cylinder member and the first cylinder member (22, 21) on the side of the first cylinder member. The inside formed integrally with the second cylindrical member or the first cylindrical member so as to protrude cylindrically from an end surface (211) of the first cylindrical member and to be connected to the first cylindrical member or the second cylindrical member. Projecting portions (80, 81, 82, 83, 84);
The end surface (211) of the first cylinder member or the end surface of the first cylinder member, which is the other end surface (21, 22) of the second cylinder member or the first cylinder member on the side of the second cylinder member. The first cylindrical member or the first cylindrical member is protruded in a cylindrical shape from an end surface (222) of the second cylindrical member and connected to the second cylindrical member or the first cylindrical member so that an inner wall abuts on an outer wall of the inner protruding portion. Outer projections (90, 91, 92, 93, 94) formed integrally with the second tubular member;
An outer protruding end surface (901, 911, 931, 941), which is an end surface of the outer protruding portion, contacts an end surface (222) of the second cylindrical member or an end surface (211) of the first cylindrical member;
The end face (801, 831, 841) or end (811) of the inner protruding portion and the outer protruding end face are formed at positions shifted in the axial direction,
The housing has a welded portion for welding and fixing the outer protruding end surface to the end surface (222) of the second cylindrical member or the end surface (211) of the first cylindrical member.
The fuel injection device (1), wherein a length of the welded portion in a radial direction of the second cylindrical member is at least longer than the outer protruding end surface.   The said inside protrusion part is integrally formed with the said 2nd cylinder member, and the inside corner part of the said 3rd cylinder member side end part or the said 1st cylinder member side end part is chamfered, or 3. The fuel injection device according to 2. The inner protruding portion is formed such that at least a part of the outer wall in the axial direction is closer to the axis from one side in the axial direction to the other side, or from the other side to the one side,
The said outer protrusion part is formed so that at least one part of an inner wall of an inner wall may approach an axis | shaft from one side of an axial direction to the other side, or from the other side to one side. The fuel injection device according to claim 1. The inner protruding portions (60, 80) are formed on the inner large-diameter portion (602, 802) and the inner small-diameter portion having an outer diameter smaller than the inner large-diameter portion formed on the inner cylindrical portion side of the second cylindrical member. (603, 803),
The outer protruding portions (70, 90) are formed on an outer large-diameter portion (702, 902) and an outer small-diameter portion formed on the second cylindrical member side of the outer large-diameter portion and having an inner diameter smaller than the outer large-diameter portion. (703, 903),
The fuel injection device according to any one of claims 1 to 4, wherein the inner large-diameter portion and the outer small-diameter portion are formed so as to overlap in an axial direction. The inner protruding portions (64, 84) are formed on the inner small-diameter portion (643, 843) and the inner large-diameter portion formed on the inner cylindrical portion side of the second cylindrical member and having an outer diameter larger than the inner small-diameter portion ( 642, 842),
The outer projecting portions (74, 94) are formed on the outer small-diameter portion (743, 943) and the outer large-diameter portion (742) formed on the second cylindrical member side of the outer small-diameter portion and having an inner diameter larger than the outer small-diameter portion. , 942)
The fuel injection device according to any one of claims 1 to 4, wherein the inner large-diameter portion and the outer small-diameter portion are formed so as to overlap in an axial direction. The inner protruding portions (60, 64, 80, 84) have inner locking surfaces (604, 644, 804) formed between the inner large-diameter portion and the inner small-diameter portion so as to expand annularly outward in the radial direction. , 844),
The outer protruding portion (70, 74, 90, 94) is formed between the outer large-diameter portion and the outer small-diameter portion so as to expand annularly inward in the radial direction, and is capable of locking the inner locking surface. The fuel injection device according to claim 5 or 6, further comprising a locking surface (704, 744, 904, 944). A movable core (40) provided reciprocally in the fuel passage together with the needle;
A fixed core (50) provided on the opposite side of the movable core inside the housing from the valve seat;
A coil (57) provided outside the housing and capable of attracting the movable core to the fixed core side and energizing the needle to the opposite side to the valve seat when energized;
A valve seat-side biasing member (52) capable of biasing the needle and the movable core toward the valve seat.
The first cylinder member and the third cylinder member are formed of a magnetic material,
The fuel injection device according to any one of claims 1 to 7, wherein the second cylindrical member is formed of a non-magnetic material.   The fuel injection device according to claim 8, wherein the third cylindrical member is formed integrally with the fixed core such that an inner wall is connected to an outer wall of the fixed core. The needle has a contact surface (34) that can contact a surface of the movable core on the fixed core side,
The fuel injection device according to any one of claims 1 to 9, wherein the movable core is provided so as to be relatively movable with respect to the needle so as to be in contact with the contact surface or to be separated from the contact surface. .   The fuel injection device according to claim 10, further comprising a gap forming member (54) capable of forming a gap (C1) between the contact surface and the movable core.

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