JP2017186979A - Fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection device capable of injecting a fuel with high accuracy while suppressing unintended secondary valve opening.SOLUTION: A nozzle 10 has nozzle cylindrical portions 11, 12 having a fuel passage 100 inside, a nozzle bottom portion 13 closing an end portion of one of the nozzle cylindrical portions 12, an injection hole 14 formed in a state of penetrating through the nozzle bottom portion 13 to inject the fuel in the fuel passage 100, and a valve seat 15 annularly formed around the injection hole 14 on a face at a side opposite to the nozzle cylindrical portion 12 of the nozzle bottom portion 13. A needle 40 has a rod-shaped first needle body 41, a seal portion 43 formed on one end of the first needle body 41 so that it can be kept into contact with the valve seat 15, a rod-shaped second needle body 42 disposed at a side opposite to the valve seat 15 with respect to the first needle body 41, and a flange portion 44 disposed at a radial outer side of the second needle body 42. A movable core 50 is disposed relatively movably to a fixed core 20 and the needle 40 at a side opposite to the nozzle 10 of the fixed core 20.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, there is a valve seat around the nozzle hole on the outer wall of the nozzle, and when the needle is pushed out, the seal portion of the needle that is in contact with the valve seat is separated from the valve seat and is opened. There are known fuel injection devices. For example, in the fuel injection device disclosed in Patent Document 1, the needle includes a rod-shaped first needle body having a seal portion formed at one end and a rod-shaped second needle body provided on the opposite side of the seal portion of the first needle body. It consists of. A movable core is provided integrally with the second needle body at the end of the second needle body opposite to the first needle body. The first needle body and the second needle body are formed separately. In a state where the seal portion is in contact with the valve seat, a gap is formed between the first needle body and the second needle body.

US Pat. No. 7,422,166

  In the fuel injection device of Patent Document 1, the first needle body and the second needle body are formed separately, and the movable core is provided separately from the first needle body. Therefore, the inertial mass of the first needle body is small, and the kinetic energy of the first needle body when the seal portion collides with the valve seat is small when the valve is closed. Thereby, suppression of the unintended secondary valve opening by the seal part which collided with the valve seat bounces is aimed at.

Further, in the fuel injection device disclosed in Patent Document 1, a gap is formed between the first needle body and the second needle body in a state where the seal portion is in contact with the valve seat. By accelerating the second needle body and causing it to collide with the first needle body, it is possible to inject a relatively high-pressure fuel.
However, in the fuel injection device of Patent Document 1, since the movable core and the second needle body are integrally formed, the responsiveness of the movable core is deteriorated, and the fuel injection accuracy may be reduced.

  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 fuel with high accuracy while suppressing unintended secondary valve opening.

  The fuel injection device (1) according to the present invention includes a nozzle (10), a fixed core (20), a needle (40), a movable core (50), a coil (60), a first biasing member (71), and a second attachment. And a biasing member (72).

The nozzle is formed so as to penetrate the nozzle cylinder part (11, 12) having the fuel passage (100) on the inner side, the nozzle bottom part (13) closing one end of the nozzle cylinder part, and the nozzle bottom part, and the fuel in the fuel passage is injected. And a valve seat (15) formed annularly around the nozzle hole on the surface of the nozzle bottom opposite to the nozzle cylinder.
The fixed core is provided on the opposite side of the nozzle bottom of the nozzle cylinder.

The needle has a rod-shaped first needle body (41), a seal portion (43) formed at one end of the first needle body so as to be able to contact the valve seat, and the first needle body on the opposite side of the valve seat. The provided rod-shaped second needle body (42), the collar part (44) provided on the radially outer side of the second needle body, and the collar upper surface (441) formed on the opposite side to the valve seat of the collar part And a flange lower surface (442) formed on the valve seat side of the flange, and opens and closes the nozzle hole when the seal portion is separated from the valve seat or comes into contact with the valve seat.
The movable core (50) is provided on the opposite side of the fixed core from the nozzle so as to be movable relative to the fixed core and the needle, and has a movable core lower surface (502) that can come into contact with or separate from the upper surface of the collar. Have.
When energized, the coil (60) attracts the movable core toward the fixed core, causes the lower surface of the movable core to contact the upper surface of the collar, and moves the needle in the valve opening direction, which is the direction in which the seal portion is separated from the valve seat. It is possible to make it.
The first urging member (71) can urge the first needle body in the valve closing direction, which is the direction in which the seal portion abuts the valve seat.
The second urging member (72) can urge the movable core in the valve closing direction.

In the present invention, the movable core is provided to be movable relative to the needle. Therefore, when the needle is closed, that is, when the seal portion collides with the valve seat, the movable core having a large inertial mass moves in the valve closing direction due to inertia regardless of the needle. That is, the inertial mass of the first needle body can be reduced. Thereby, the kinetic energy of the 1st needle body when a seal part collides with a valve seat can be made small. Therefore, an unintended secondary valve opening due to the seal portion colliding with the valve seat rebounding can be suppressed.
In the present invention, the movable core and the second needle body are formed separately. Therefore, the responsiveness of the movable core can be improved, and the fuel injection accuracy can be increased.

  In the present invention, when the seal portion is in contact with the valve seat, when the gap (S1) can be formed between the lower surface of the movable core and the upper surface of the flange portion, the movable core is accelerated through the gap. It can be made to collide with the upper surface of the buttocks. Thereby, even when the biasing force of the first biasing member is high, that is, when the needle closing force is high, the needle can be opened. Therefore, the pressure of the fuel in the fuel passage can be increased, and high-pressure fuel can be injected.

Sectional drawing which shows the fuel-injection apparatus by 1st Embodiment of this invention. The enlarged view of the II part of FIG. It is sectional drawing which shows the fixed core and movable core of the fuel-injection apparatus by 1st Embodiment of this invention, Comprising: The figure which shows the state different from FIG. It is sectional drawing which shows the fixed core and movable core of the fuel-injection apparatus by 1st Embodiment of this invention, Comprising: The figure which shows the state different from FIG. It is sectional drawing which shows the fixed core and movable core of the fuel-injection apparatus by 1st Embodiment of this invention, Comprising: The figure which shows the state different from FIG. It is sectional drawing which shows the fixed core and movable core of the fuel-injection apparatus by 1st Embodiment of this invention, Comprising: The figure which shows the state different from FIG. Sectional drawing which shows the cylinder member and guide member of the fuel-injection apparatus by 2nd Embodiment of this invention. Sectional drawing which shows the cylinder member and guide member of the fuel-injection apparatus by 3rd Embodiment of this invention. Sectional drawing which shows the cylinder member and guide member of the fuel-injection apparatus by 4th Embodiment of this invention. Sectional drawing which shows the cylinder member and guide member of the fuel-injection apparatus by 5th Embodiment of this invention. Sectional drawing which shows the cylinder member and guide member of the fuel-injection apparatus by 6th Embodiment of this invention. Sectional drawing which shows the cylinder member and guide member of the fuel-injection apparatus by 7th Embodiment of this invention. Sectional drawing which shows the fuel-injection apparatus by 8th Embodiment of this invention. Sectional drawing which shows the fuel-injection apparatus by 9th Embodiment of this invention.

Hereinafter, fuel injection devices according to a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)
A fuel injection device according to a first embodiment of the present invention is shown in FIG. 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 10, a fixed core 20, an introduction pipe 30, a needle 40, a movable core 50, a cylindrical member 80, a guide member 90, a coil 60, a spring 71 as a first biasing member, and a second biasing member. And a spring 73 as a movable core urging member.
The nozzle 10 includes nozzle cylinder portions 11 and 12, a nozzle bottom portion 13, a nozzle hole 14, a valve seat 15 and the like.

  The nozzle cylinder portion 11 is formed in a cylindrical shape from a magnetic material such as stainless steel. The nozzle cylinder portion 12 is formed in a cylindrical shape from a metal such as stainless steel. One end of the nozzle cylinder 12 is joined to the end of the nozzle cylinder 11 by welding, for example. The nozzle cylinder part 11 and the nozzle cylinder part 12 are provided coaxially. A fuel passage 100 through which fuel can flow is formed inside the nozzle cylinder portion 11 and the nozzle cylinder portion 12.

  The nozzle bottom 13 is formed of, for example, a metal such as stainless steel like the nozzle cylinder 12 and closes the end of the nozzle cylinder 12 opposite to the nozzle cylinder 11. The nozzle bottom part 13 and the nozzle cylinder part 12 are integrally formed from the same material. Thus, the nozzle 10 is formed in a bottomed cylindrical shape.

  One nozzle hole 14 is formed so as to penetrate the center of the nozzle bottom 13 in the thickness direction. The nozzle hole 14 is formed in a substantially cylindrical shape around the axis Ax1 of the nozzle 10. The nozzle hole 14 connects the fuel passage 100 and the outside of the nozzle 10.

  The valve seat 15 is formed in an annular shape around the nozzle hole 14 on the surface of the nozzle bottom 13 opposite to the nozzle cylinder 12. The valve seat 15 is formed in an outwardly opening taper shape so as to move away from the axis Ax1 of the nozzle 10 as it goes from the fuel passage 100 to the outside of the nozzle 10.

The fixed core 20 is formed in a cylindrical shape from a magnetic material such as stainless steel. The fixed core 20 is provided on the side opposite to the nozzle bottom 13 of the nozzle 10. The fixed core 20 is provided so that the outer edge portion of the end portion on the nozzle 10 side is joined to the end portion of the nozzle tube portion 11 opposite to the nozzle tube portion 12. The fixed core 20 and the nozzle cylinder part 11 are joined by welding, for example.
The fixed core 20 has a concave portion 21, a concave portion 22, a hole portion 200, a flow path 23, and the like.

The recess 21 is formed so as to be recessed in a substantially cylindrical shape from the center of the fixed core upper surface 201 which is the end surface of the fixed core 20 opposite to the nozzle 10 to the nozzle 10 side. The recess 22 is formed so as to be recessed in a substantially cylindrical shape from the center of the fixed core lower surface 202 which is an end surface of the fixed core 20 on the nozzle 10 side to the side opposite to the nozzle 10. The inner diameter of the recess 22 is larger than the inner diameter of the recess 21.
The hole 200 is formed in a substantially cylindrical shape so as to connect the bottom surface of the recess 21 and the bottom surface of the recess 22. Here, the recess 21, the recess 22, and the hole 200 are formed coaxially with the axis Ax <b> 2 of the fixed core 20 as the center.
The flow path 23 is formed so as to connect the fixed core upper surface 201 and the bottom surface of the recess 22 on the radially outer side of the recess 21. For example, a plurality of the flow paths 23 are formed at equal intervals in the circumferential direction of the fixed core 20.

  The introduction pipe 30 is formed in a cylindrical shape from a magnetic material such as stainless steel. The introduction pipe 30 is provided on the opposite side of the fixed core 20 from the nozzle 10. A magnetic throttle unit 2 is provided between the introduction pipe 30 and the fixed core 20.

The magnetic aperture portion 2 is formed in a substantially cylindrical shape from, for example, a nonmagnetic material. One end of the magnetic diaphragm 2 is joined to the fixed core 20 and the other end is joined to one end of the introduction pipe 30. The magnetic throttle unit 2, the fixed core 20, and the introduction pipe 30 are joined by welding, for example. The fixed core 20, the magnetic restrictor 2, and the introduction pipe 30 are provided coaxially along the axis Ax 2 of the fixed core 20.
The introduction pipe 30 has a support portion 31, a flow path 32, a locking surface 33, and a step surface 34.
The support portion 31 is formed in a substantially cylindrical shape inside the introduction pipe 30. The support part 31 has a substantially cylindrical inner wall.

The flow path 32 is formed so as to connect the end faces on both sides of the support portion 31. Thereby, the space on the valve seat 15 side with respect to the support portion 31 and the space on the opposite side of the valve seat 15 with respect to the support portion 31 are communicated by the flow path 32. A plurality of flow paths 32 are formed at equal intervals in the circumferential direction of the support portion 31.
The locking surface 33 is formed in an annular shape on the valve seat 15 side of the support portion 31. The step surface 34 is formed in an annular shape on the radially outer side of the locking surface 33 and closer to the valve seat 15 than the locking surface 33.
The introduction pipe 30 forms a part of the fuel passage 100 inside.
The needle 40 includes a first needle body 41, a second needle body 42, a seal portion 43, a flange portion 44, a spring seat 45, and the like.

The first needle body 41 and the second needle body 42 are formed in a rod shape, more specifically, a long column shape, for example, from a metal such as stainless steel. In the present embodiment, the first needle body 41 and the second needle body 42 are formed separately.
The first needle body 41 is provided inside the nozzle 10 so as to be capable of reciprocating in the axial direction. The seal portion 43 is formed at the end of the first needle body 41 on the nozzle hole 14 side.

Here, the first needle body 41 is provided on the inner side of the nozzle 10 so that the seal portion 43 is located on the opposite side of the nozzle cylinder portion 11 with respect to the valve seat 15. Therefore, the end portion of the first needle body 41 on the seal portion 43 side is located inside the injection hole 14. The outer diameter of the seal portion 43 is larger than the outer diameter of the first needle body 41 and the inner diameter of the injection hole 14. The surface of the seal portion 43 on the valve seat 15 side is formed in a tapered shape so as to correspond to the shape of the valve seat 15. A surface of the seal portion 43 on the valve seat 15 side can contact the valve seat 15.

In the first needle body 41, a plurality of axial portions of the outer wall can slide with the inner wall of the nozzle cylinder portion 11, the inner wall of the nozzle cylinder portion 12, and the inner wall of the injection hole 14. Thereby, the movement of the first needle body 41 in the axial direction is guided by the nozzle 10. When the first needle body 41 reciprocates in the axial direction inside the nozzle 10, the seal portion 43 is separated from the valve seat 15 or abuts against the valve seat 15. The needle 40 opens when the first needle body 41 is pushed out from the nozzle 10 and the seal portion 43 is separated from the valve seat 15, and closes when the seal portion 43 contacts the valve seat 15. When the needle 40 opens or closes, the nozzle hole 14 opens and closes. Hereinafter, the direction in which the seal portion 43 is separated from the valve seat 15 is referred to as a valve opening direction, and the direction in which the seal portion 43 contacts the valve seat 15 is referred to as a valve closing direction.
As described above, the fuel injection device 1 according to the present embodiment is a so-called externally-open fuel injection device in which the seal portion 43 is separated from the valve seat 15 and opened when the first needle body 41 is pushed out of the nozzle 10. It is.

  The spring seat 45 is formed in a substantially annular plate shape, for example. The spring seat 45 is provided on the outer wall of the end portion of the first needle body 41 opposite to the seal portion 43. The spring seat 45 is provided such that the inner edge portion is fitted to the outer wall of the first needle body 41. Thereby, the spring seat 45 is not movable relative to the first needle body 41.

  An annular step surface 16 that faces the fixed core 20 is formed on the inner wall of the nozzle cylinder portion 12. The spring 71 is a coil spring, for example, and is provided between the spring seat 45 and the step surface 16. One end of the spring 71 is locked to the spring seat 45 and the other end is locked to the step surface 16. The spring 71 is compressed in the axial direction by the spring seat 45 and the step surface 16. Therefore, the spring 71 biases the first needle body 41 in the valve closing direction. Thereby, the seal portion 43 is pressed against the valve seat 15.

  The second needle body 42 is provided substantially coaxially with the first needle body 41 on the side opposite to the valve seat 15 with respect to the first needle body 41. In the present embodiment, the outer diameter of the second needle body 42 is slightly smaller than the outer diameter of the first needle body 41. The second needle body 42 is provided so as to be capable of reciprocating in the axial direction inside the fixed core 20, the magnetic throttle portion 2, and the introduction pipe 30. In the second needle main body 42, the outer wall at the end on the first needle main body 41 side can slide with the hole 200 of the fixed core 20. In addition, the outer wall of the end of the second needle main body 42 opposite to the first needle main body 41 can slide with the inner wall of the support portion 31 of the introduction pipe 30. Thereby, the movement of the second needle body 42 in the axial direction is guided by the fixed core 20 and the support portion 31 of the introduction pipe 30.

  The flange portion 44 is formed in a substantially annular shape so as to protrude radially outward from the outer wall of the second needle body 42. In the present embodiment, the flange portion 44 is formed integrally with the second needle body 42. A substantially annular flange upper surface 441 is formed on the support portion 31 side of the flange portion 44, that is, on the side opposite to the valve seat 15. A flange lower surface 442 is formed on the valve seat 15 side of the flange 44.

The movable core 50 is formed in a cylindrical shape from a magnetic material such as stainless steel. The movable core 50 is provided on the opposite side of the fixed core 20 from the nozzle 10. The movable core 50 is provided so as to be capable of reciprocating in the axial direction inside the end portions of the magnetic throttle portion 2 and the introduction pipe 30 on the magnetic throttle portion 2 side, that is, in the fuel passage 100. That is, the movable core 50 is provided to be movable relative to the fixed core 20.
The movable core 50 has a recess 51, a hole 500, a flow path 52, and the like.
The recess 51 is formed so as to be recessed in a substantially cylindrical shape from the center of the movable core upper surface 501 which is the end surface of the movable core 50 opposite to the fixed core 20 to the fixed core 20 side.

The hole 500 is formed in a substantially cylindrical shape so as to connect the bottom surface of the recess 51 and the movable core lower surface 502 that is the end surface of the movable core 50 on the fixed core 20 side. Here, the recess 51 and the hole 500 are formed coaxially with the axis Ax5 of the movable core 50 as the center.
The flow path 52 is formed so as to connect the movable core upper surface 501 and the movable core lower surface 502 on the radially outer side of the recess 51. For example, a plurality of flow paths 52 are formed at equal intervals in the circumferential direction of the movable core 50.

  As shown in FIG. 2, the movable core 50 is provided between the fixed core upper surface 201 and the step surface 34 of the introduction pipe 30 in a state where the second needle body 42 is inserted inside the hole 500. The movable core 50 is movable relative to the second needle body 42. Here, the inner wall of the hole 500 of the movable core 50 and the outer wall of the second needle body 42 are slidable.

The flange 44 is formed on the valve seat 15 side with respect to the movable core lower surface 502 on the outer wall of the second needle body 42. Note that the flange portion 44 is formed at a position through which a virtual plane including the fixed core upper surface 201 passes when the seal portion 43 is in contact with the valve seat 15 and is closed (see FIG. 2).
The cylindrical member 80 is formed in a cylindrical shape from a metal such as stainless steel. The tubular member 80 is provided on the valve seat 15 side of the movable core 50 so as to be movable relative to the fixed core 20 and the movable core 50.
The cylinder member 80 has a cylinder main body 81 and an in-cylinder protruding portion 82.
The cylinder body 81 is formed in a substantially cylindrical shape. The in-cylinder protruding portion 82 is formed in a substantially annular shape so as to protrude inward in the radial direction from the inner wall of one end of the cylinder main body 81.

In the present embodiment, the cylindrical member 80 is provided on the valve seat 15 side of the movable core 50 such that the second needle main body 42 is inserted inside and the flange portion 44 is positioned inside the cylindrical main body 81. The cylindrical member 80 is movable relative to the flange portion 44 and the second needle main body 42. Therefore, the in-cylinder upper surface 821, which is the end surface of the in-cylinder protruding portion 82 on the side opposite to the valve seat 15, can abut against or be separated from the flange lower surface 442. Here, the inner wall of the cylinder body 81 is slidable with the outer wall of the flange portion 44. Further, the inner edge portion of the in-cylinder protruding portion 82 is slidable with the outer wall of the second needle main body 42.
A cylinder upper surface 801, which is the surface of the cylinder member 80 opposite to the valve seat 15, can contact the movable core lower surface 502 or be separated from the movable core lower surface 502.

The spring 72 is, for example, a coil spring, and is provided between the cylindrical member 80 and the bottom surface of the concave portion 21 of the fixed core 20. One end of the spring 72 is locked to the cylinder lower surface 802 that is the surface of the cylinder member 80 on the valve seat 15 side, and the other end is locked to the bottom surface of the concave portion 21 of the fixed core 20. The spring 72 is compressed in the axial direction by the cylinder lower surface 802 and the bottom surface of the recess 21. Therefore, the spring 72 biases the tubular member 80 in the valve closing direction. As a result, the cylinder upper surface 801 is pressed against the movable core lower surface 502, and the cylinder upper surface 821 is pressed against the flange lower surface 442. That is, the spring 72 can bias the movable core 50 in the valve closing direction via the cylindrical member 80. The spring 72 can bias the second needle body 42 in the valve closing direction via the tubular member 80 and the flange portion 44.
The guide member 90 is formed in a cylindrical shape from a metal such as stainless steel. The guide member 90 is provided inside the recess 21 of the fixed core 20.

  The guide member 90 has a guide body 91. The guide body 91 is formed in a substantially cylindrical shape. The guide body 91 is provided so that its outer wall is fitted into the inner wall of the recess 21 of the fixed core 20 and is not movable relative to the fixed core 20. The guide body 91 is provided coaxially with the fixed core 20. In this embodiment, the guide upper surface 901, which is the surface of the guide member 90 opposite to the valve seat 15, is located on the same plane as the fixed core upper surface 201. A guide lower surface 902 that is a surface of the guide member 90 on the valve seat 15 side is separated from the bottom surface of the recess 21.

  The inner wall of the guide body 91 is slidable with the outer wall of the cylinder body 81. Therefore, the cylindrical member 80 is guided to move in the axial direction by the guide member 90. That is, in the present embodiment, the second needle body 42 and the cylindrical member 80 are supported by the fixed core 20 and the guide member 90 so as to be reciprocally movable in the axial direction.

The spring 73 is, for example, a coil spring, and is provided between the locking surface 33 of the introduction pipe 30 and the bottom surface of the concave portion 51 of the movable core 50 (see FIGS. 1 and 2). One end of the spring 73 is locked to the locking surface 33 and the other end is locked to the bottom surface of the recess 51. The spring 73 is compressed in the axial direction by the locking surface 33 and the bottom surface of the recess 51. Therefore, the spring 73 biases the movable core 50 in the valve opening direction. That is, the spring 73 can bias the movable core 50 in the valve opening direction.
The coil 60 is formed in a substantially cylindrical shape by winding a winding such as copper. The coil 60 is provided so as to be positioned on the radially outer side of the magnetic diaphragm portion 2 and the fixed core 20.

  In the present embodiment, a yoke 61 is further provided. The yoke 61 is formed in a cylindrical shape from a magnetic material such as stainless steel. The yoke 61 covers the outer side in the radial direction of the coil 60, and is provided so that one end is in contact with the outer wall of the nozzle cylinder portion 11 and the fixed core 20, and the other end is in contact with the outer wall of the introduction pipe 30. The inner side of the yoke 61, the periphery of the coil 60, the outer wall of the fixed core 20, the outer wall of the magnetic throttle unit 2, and the outer wall of the introduction pipe 30 are covered with a mold part 62 made of resin.

The coil 60 generates magnetic flux when energized. When a magnetic flux is generated in the coil 60, the magnetic flux flows through the fixed core 20, the yoke 61, the introduction pipe 30, and the movable core 50 so as to avoid the magnetic throttle unit 2, thereby forming a magnetic circuit. Thereby, the movable core 50 is attracted | sucked to the fixed core 20 side.
In the present embodiment, the fuel injection device 1 is provided in the engine such that, for example, the seal portion 43 faces the lower side in the vertical direction so that the axis Ax1 of the nozzle 10 is substantially along the vertical direction.

  In this embodiment, when the needle 40 is closed, that is, for example, when energization to the coil 60 is stopped and the seal portion 43 is in contact with the valve seat 15 (see FIGS. 1 and 2), the movable core 50 is used. The cylindrical member 80 is stationary at a position where the urging forces of the spring 72 and the spring 73 are balanced with the movable core lower surface 502 and the cylindrical upper surface 801 in contact with each other. At this time, the position of the movable core lower surface 502 is substantially the center in the axial direction of the magnetic diaphragm portion 2. Further, at this time, the flange lower surface 442 and the in-cylinder upper surface 821 are in contact with each other, the upper end surface 411 which is the end surface opposite to the valve seat 15 of the first needle body 41, and the valve seat 15 of the second needle body 42. The lower end surface 422 which is the side end surface is in contact.

  Further, at this time, the movable core lower surface 502 and the collar upper surface 441 are separated from each other, and a gap S1 is formed between the movable core lower surface 502 and the collar upper surface 441 (see FIG. 2). The size of the gap S1 in the axial direction of the second needle body 42, that is, the distance d1 between the movable core lower surface 502 and the collar upper surface 441 is smaller than the distance d2 between the movable core lower surface 502 and the fixed core upper surface 201. Is set. The second needle main body 42 is movable in the axial direction within a range (d1) in which the flange portion 44 is movable between the movable core lower surface 502 and the in-cylinder upper surface 821.

  When the coil 60 is energized and the movable core 50 is attracted toward the fixed core 20 and moved in the valve opening direction, the movable core lower surface 502 comes into contact with the collar upper surface 441. When the movable core 50 further moves in the valve opening direction, the second needle body 42 is pushed by the movable core 50 in the valve opening direction via the flange portion 44. Accordingly, the first needle body 41 moves in the valve opening direction, and the seal portion 43 is separated from the valve seat 15 and opened.

  A filter 3 is provided inside the end of the introduction pipe 30 opposite to the fixed core 20. For example, a fuel pipe is connected to the end of the introduction pipe 30 opposite to the fixed core 20. Thereby, fuel is introduced into the fuel passage 100 from the fuel pipe. The filter 3 collects foreign matters in the passing fuel.

  The fuel that has flowed into the inside of the introduction pipe 30 from the fuel pipe flows through the flow path 32, the flow path 52, the flow path 23, and the nozzle cylinder portions 11 and 12, and is guided to the injection hole 14. The fuel that has flowed into the introduction pipe 30 fills the inside of the introduction pipe 30 and the inside of the nozzle cylinder portions 11 and 12, that is, the fuel passage 100. In the present embodiment, relatively high pressure fuel is introduced into the fuel passage 100 when the fuel injection device 1 is operated. Therefore, the fuel pressure in the fuel passage 100 is relatively high. In the present embodiment, the urging force of the spring 71 is set to be greater than at least the fuel pressure acting on the upper end surface 411 of the first needle body 41.

Next, the operation of the fuel injection device 1 according to the present embodiment will be described in detail with reference to FIGS.
As shown in FIGS. 1 and 2, when the coil 60 is not energized, the needle 40 (first needle body 41) is closed.

  When the coil 60 is energized in the state shown in FIGS. 1 and 2, a magnetic flux is generated, and the movable core 50 is attracted in the fixed core 20 side, that is, in the valve opening direction. Thereby, the movable core 50 and the cylindrical member 80 move in the valve opening direction against the urging force of the spring 72, and the movable core lower surface 502 collides with the collar upper surface 441 (see FIG. 3). When the movable core 50 collides with the collar portion 44, the first needle body 41 is pushed in the valve opening direction by the second needle body 42, and the seal portion 43 is separated from the valve seat 15 and opened. At this time, since the movable core 50 collides with the flange portion 44 while accelerating in the gap S1, the needle 40 is opened even when the urging force of the spring 71 is high, that is, when the closing force of the needle 40 is high. Can be valved.

  When the movable core 50 is further sucked in the valve opening direction from the state shown in FIG. 3, the movable core lower surface 502 comes into contact with the fixed core upper surface 201 (see FIG. 4). At this time, the needle 40 is fully opened. That is, in this embodiment, the full lift amount of the needle 40 is equal to the distance obtained by subtracting the distance d1 from the distance d2 shown in FIG.

When the energization of the coil 60 is stopped in the state shown in FIG. 4, the first needle body 41, the second needle body 42, and the movable core 50 are urged in the valve closing direction by the urging force of the spring 71, as shown in FIG. 3. Then, the seal portion 43 collides with the valve seat 15 and closes. In the present embodiment, since the movable core 50 is provided separately so as to be movable relative to the needle 40 (first needle body 41), the movable portion having a large inertial mass when the seal portion 43 collides with the valve seat 15. The core 50 moves in the valve closing direction by inertia regardless of the first needle body 41. Thereby, the kinetic energy of the 1st needle main body 41 when the seal part 43 collides with the valve seat 15 can be made small.
When the movable core 50 moves in the valve closing direction due to inertia, the cylindrical member 80 is urged by the spring 72 and moves together with the movable core 50 in the valve closing direction. Thereby, the cylinder upper surface 821 contacts the collar lower surface 442 (see FIG. 2).

When the movable core 50 and the tubular member 80 are further moved in the valve closing direction, the second needle body 42 is pulled up by the in-cylinder protruding portion 82 (see FIG. 5). In the present embodiment, since the first needle body 41 and the second needle body 42 are formed separately, at this time, the first needle body 41 and the second needle body 42 are separated from each other, and the first needle body 41 is separated. A gap S <b> 2 is formed between the upper end surface 411 and the lower end surface 422 of the second needle body 42. The second needle body 42 may further move in the valve closing direction due to inertia (see FIG. 6).
When the movable core 50 moves in the valve opening direction by the urging force of the spring 73 from the state of FIG. 5 or FIG. 6, the initial state shown in FIGS.

  Thus, in the present embodiment, when the needle 40 operates as an on-off valve (see FIGS. 1 to 6), the cylindrical member 80 moves relative to the guide member 90. At this time, the outer wall of the cylinder body 81 of the cylinder member 80 slides with the inner wall of the guide body 91 of the guide member 90. Therefore, for example, the wear of the fixed core 20 can be prevented as compared with the case where the cylindrical member 80 slides on the inner wall of the recess 21 of the fixed core 20.

  In the present embodiment, the inner wall of the cylinder main body 81 is slidable with the outer wall of the flange portion 44. Further, the inner edge portion of the in-cylinder protruding portion 82 is slidable with the outer wall of the second needle main body 42. Furthermore, the inner wall of the hole 500 of the movable core 50 can slide with the outer wall of the second needle body 42. Therefore, the movable core 50 and the second needle body 42 are guided in the axial reciprocation by the cylindrical member 80 and the guide member 90. Thereby, the attitude | position at the time of reciprocating movement of the movable core 50 and the 2nd needle main body 42 is stabilized.

Next, a method for manufacturing the fuel injection device 1 according to this embodiment will be described.
The method for manufacturing the fuel injection device 1 includes the following steps.
(First needle body assembly process)
The first needle body 41 is inserted into the nozzle 10 from the nozzle hole 14. A spring 71 is provided on the stepped surface 16 of the nozzle 10. The spring seat 45 is fitted to the outer wall of the end portion of the first needle body 41 opposite to the seal portion 43 so that the spring 71 is compressed by a predetermined amount.
(Second needle body assembly process)
The guide member 90 is press-fitted inside the recess 21 of the fixed core 20. As a result, the guide member 90 is in an interference fit state inside the fixed core 20. A spring 72 is provided inside the recess 21 and the guide member 90. A cylindrical member 80 is provided inside the guide member 90. The second needle body 42 is inserted inside the cylindrical member 80 and the fixed core 20. Accordingly, the second needle main body 42 is in a state in which the flange lower surface 442 is in contact with the in-cylinder upper surface 821.

(Fixed core assembly process)
The fixed core 20 is joined to the end of the nozzle 10 opposite to the nozzle bottom 13 and the joint is welded.
(Moving core assembly process)
The magnetic restrictor 2 is joined to the end of the fixed core 20 opposite to the nozzle 10 and the joint is welded. The movable core 50 is inserted from the opposite side of the second needle body 42 to the first needle body 41.
(Introduction pipe assembly process)
A spring 73 is provided on the side of the movable core 50 opposite to the fixed core 20. The introduction pipe 30 is joined to the end of the magnetic diaphragm 2 opposite to the fixed core 20, and the joint is welded.

  Through the above steps, the upper end surface 411 of the first needle body 41 and the lower end surface 422 of the second needle body 42 come into contact with each other, the flange lower surface 442 and the in-cylinder upper surface 821 of the cylinder member 80 come into contact with each other, The cylinder upper surface 801 of the member 80 and the movable core lower surface 502 come into contact with each other, and a gap S1 is formed between the flange upper surface 441 and the movable core lower surface 502. At this time, the flange lower surface 442 and the in-cylinder upper surface 821 may be separated from each other. Further, the upper end surface 411 and the lower end surface 422 may be separated to form a gap S2.

  As described above, the fuel injection device 1 according to the present embodiment includes the nozzle 10, the fixed core 20, the needle 40, the movable core 50, the coil 60, the spring 71 as the first urging member, and the second urging member. And a spring 72.

The nozzle 10 is formed so as to penetrate the nozzle cylinder portions 11 and 12 having the fuel passage 100 inside, the nozzle bottom portion 13 closing one end of the nozzle cylinder portion 12, and the nozzle bottom portion 13, and the fuel in the fuel passage 100 is injected. The nozzle hole 14 and a valve seat 15 formed in an annular shape around the nozzle hole 14 are provided on the surface of the nozzle bottom 13 opposite to the nozzle cylinder 12.
The fixed core 20 is provided on the side opposite to the nozzle bottom portion 13 of the nozzle cylinder portion 11.

  The needle 40 has a rod-shaped first needle body 41 and a seal portion 43 formed at one end of the first needle body 41 so as to be able to contact the valve seat 15, and is opposite to the valve seat 15 with respect to the first needle body 41. A rod-shaped second needle body 42 provided on the outer side, a flange 44 provided on the radially outer side of the second needle body 42, a flange upper surface 441 formed on the opposite side of the valve seat 15 of the flange 44, and The flange portion 44 has a flange lower surface 442 formed on the valve seat 15 side of the flange portion 44, and opens and closes the nozzle hole 14 when the seal portion 43 is separated from the valve seat 15 or contacts the valve seat 15.

  The movable core 50 is provided on the opposite side of the fixed core 20 from the nozzle 10 so as to be movable relative to the fixed core 20 and the needle 40, and can be brought into contact with or separated from the collar upper surface 441. 502.

When energized, the coil 60 attracts the movable core 50 toward the fixed core 20, brings the movable core lower surface 502 into contact with the flange upper surface 441, and in the valve opening direction in which the seal portion 43 is separated from the valve seat. The needle 40 can be moved.
The spring 71 can bias the first needle body 41 in the valve closing direction, which is the direction in which the seal portion 43 abuts the valve seat 15.
The spring 72 can bias the movable core 50 in the valve closing direction.

In the present embodiment, the movable core 50 is provided so as to be movable relative to the needle 40. Therefore, when the needle 40 is closed, that is, when the seal portion 43 collides with the valve seat 15, the movable core 50 having a large inertial mass moves in the valve closing direction by inertia regardless of the needle 40. That is, the inertial mass of the first needle body 41 can be reduced. Thereby, the kinetic energy of the 1st needle main body 41 when the seal part 43 collides with the valve seat 15 can be made small. Therefore, the unintended secondary valve opening due to the seal part 43 colliding with the valve seat 15 rebounding can be suppressed.
In the present embodiment, the movable core 50 and the second needle body 42 are formed separately. Therefore, the responsiveness of the movable core 50 can be improved, and the fuel injection accuracy can be increased.

(2) In the present embodiment, the movable core 50 can form a gap S1 between the movable core lower surface 502 and the collar upper surface 441 when the seal portion 43 is in contact with the valve seat 15. Therefore, the movable core 50 can be accelerated and collided with the collar upper surface 441 through the gap S1. Thereby, even when the biasing force of the spring 71 is high, that is, when the closing force of the needle 40 is high, the needle 40 can be opened. Therefore, the pressure of the fuel in the fuel passage 100 can be increased, and high-pressure fuel can be injected.
(3) The present embodiment further includes a cylindrical member 80. The tubular member 80 is provided on the valve seat 15 side of the movable core 50 so as to be movable relative to the second needle body 42, and has a tubular tubular body 81.

Moreover, (4) In this embodiment, the cylinder member 80 is formed on the opposite side to the valve seat 15 of the in-cylinder protruding part 82 and the in-cylinder protruding part 82 protruding radially inward from the inner wall of the cylinder main body 81. The cylinder further includes an in-cylinder upper surface 821 that can contact or be separated from the collar lower surface 442.
(5) In the present embodiment, the spring 72 can bias the movable core 50 in the valve closing direction via the cylindrical member 80.
(6) In the present embodiment, the spring 72 can bias the second needle body 42 in the valve closing direction via the cylindrical member 80 and the flange portion 44.

Moreover, (7) In this embodiment, the guide member 90 is further provided. The guide member 90 is provided on the inner wall of the recess 21 of the fixed core 20, and has a cylindrical guide body 91 whose inner wall is slidable with the outer wall of the cylinder body 81. The cylinder body 81 is provided such that the inner wall is slidable with the outer wall of the flange portion 44.
As described above, in the present embodiment, by further including the cylindrical member 80 and the guide member 90, the posture of the second needle body 42 and the movable core 50 during the reciprocating movement can be stabilized while preventing the fixed core 20 from being worn. can do.

  (11) In the present embodiment, the cylindrical member 80 is provided so as to be movable relative to the movable core 50. Therefore, for example, there is no need to fix and fix the cylindrical member 80 and the movable core 50 coaxially with high accuracy. Therefore, manufacture is easy and each of the cylindrical member 80 and the movable core 50 can be smoothly moved relative to the second needle body 42 when the fuel injection device 1 is used.

  (12) The present embodiment further includes a spring 73 as a movable core biasing member. The spring 73 can bias the movable core 50 in the valve opening direction. The spring 73 can suppress excessive movement of the movable core 50 in the valve closing direction when the needle 40 is closed, that is, after the transition from the valve opening state to the valve closing state. Therefore, the next valve opening operation can be performed quickly, and the responsiveness can be improved.

  (13) In the present embodiment, the second needle body 42 is formed separately from the first needle body 41, and a gap S <b> 2 can be formed between the first needle body 41 and the second needle body 42. Since the second needle body 42 and the first needle body 41 are formed separately, the first needle body 41 and the second needle body 42 are assembled in separate processes in the manufacturing process as described above. Can do.

  Moreover, since the 2nd needle main body 42 and the 1st needle main body 41 are formed in the different body, the inertial mass of the 1st needle main body 41 can be made smaller, and the 2nd needle main body 42 and the 1st needle main body 41 become smaller. Compared to the integrally formed configuration, unintended secondary valve opening can be more effectively suppressed.

  Further, since the gap S2 can be formed between the second needle body 42 and the first needle body 41, the movable core 50 and the second needle body 42 are accelerated in the gap S2 to collide with the first needle body 41, It is also possible to open the needle 40.

(Second Embodiment)
A part of the fuel injection device according to the second embodiment of the present invention is shown in FIG. The second embodiment is different from the first embodiment in the shapes of the fixed core 20 and the guide member 90.

  In the second embodiment, the fixed core 20 further has a step surface 24. The step surface 24 is formed in a substantially annular plane on the valve seat 15 side of the recess formed so as to be recessed radially outward from the inner wall of the end of the recess 21 on the movable core 50 side. The step surface 24 is located on the valve seat 15 side with respect to the fixed core upper surface 201 and is formed to face the movable core lower surface 502. That is, the step surface 24 is a surface on the opposite side to the valve seat 15 of the fixed core 20.

The guide member 90 further includes an outer guide protrusion 92. The guide outer protrusion 92 is formed integrally with the guide main body 91 so as to protrude in a substantially annular shape radially outward from the outer wall of the end portion of the guide main body 91 on the movable core 50 side.
The guide member 90 is provided on the fixed core 20 so that the surface of the outer guide protrusion 92 on the valve seat 15 side contacts the stepped surface 24 of the fixed core 20. Thereby, the guide member 90 is restricted from moving in the valve opening direction.

  The second embodiment is the same as the first embodiment except for the points described above. Therefore, the second embodiment can produce the same effect as the first embodiment and the effect of restricting the movement of the guide member 90 in the valve opening direction.

(Third embodiment)
A part of the fuel injection device according to the third embodiment of the present invention is shown in FIG. The third embodiment differs from the first embodiment in the shapes of the fixed core 20 and the guide member 90.
In the third embodiment, the fixed core 20 has a step surface 24 as in the second embodiment.
The guide member 90 further has a guide recess 93. The guide recess 93 is formed so as to be recessed annularly radially outward from the inner wall of the end of the guide body 91 on the valve seat 15 side.
The guide member 90 is provided on the fixed core 20 so that the outer edge portion of the guide lower surface 902 which is the surface on the valve seat 15 side is in contact with the step surface 24. Thereby, the guide member 90 is restricted from moving in the valve opening direction.

  In the present embodiment, the guide member 90 is provided on the fixed core 20 so that the end of the guide body 91 on the valve seat 15 side is in an interference fit state. That is, a force on the inner side in the radial direction from the fixed core 20 acts on the outer wall of the end portion of the guide body 91 on the valve seat 15 side, but on the outer wall of the end portion of the guide body 91 on the opposite side to the valve seat 15. No force radially inward from the fixed core 20 is applied. Therefore, distortion of the inner wall of the guide member 90 that slides with the outer wall of the cylindrical member 80 can be suppressed. Thereby, the attitude | position at the time of the reciprocating movement of the cylinder member 80 is stabilized, and the partial wear with the cylinder member 80 and the guide member 90 can be suppressed.

  The third embodiment is the same as the first embodiment except for the points described above. Therefore, the third embodiment has the same effect as the first embodiment, the effect of regulating the movement of the guide member 90 in the valve opening direction, the effect of stabilizing the posture of the cylindrical member 80 during the reciprocating movement, And the effect which suppresses the partial wear with the cylinder member 80 and the guide member 90 can be show | played.

(Fourth embodiment)
FIG. 9 shows a part of the fuel injection device according to the fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in the shape of the guide member 90.

  In the fourth embodiment, the guide member 90 further has an in-guide protrusion 94. The in-guide protrusion 94 is formed integrally with the guide body 91 so as to protrude in a substantially annular shape radially inward from the inner wall of the end of the guide body 91 on the valve seat 15 side.

In the present embodiment, when the needle 40 is closed, that is, for example, when energization to the coil 60 is stopped and the seal portion 43 is in contact with the valve seat 15 (see FIG. 9), the guide protrusion 94 The guide inner upper surface 941, which is the surface on the movable core 50 side, is separated from the cylinder lower surface 802 of the cylinder member 80, and forms a gap between the cylinder lower surface 802. The cylinder lower surface 802 can abut on the guide inner upper surface 941. The in-guide protrusion 94 can restrict excessive movement of the tubular member 80 in the valve opening direction.
In the present embodiment, in the state shown in FIG. 9, the distance between the guide inner upper surface 941 and the cylinder lower surface 802 is slightly larger than the distance between the fixed core upper surface 201 and the movable core lower surface 502.

  The configuration of the fourth embodiment is the same as that of the first embodiment except for the points described above. Therefore, 4th Embodiment can show | play the effect similar to 1st Embodiment, and can control the excessive movement to the valve opening direction of the cylinder member 80.

(Fifth embodiment)
FIG. 10 shows a part of the fuel injection device according to the fifth embodiment of the present invention. The fifth embodiment is different from the first embodiment in the shape of the cylindrical member 80.
In the fifth embodiment, the tubular member 80 further includes an out-cylinder protruding portion 83. The cylinder outside protrusion 83 is formed integrally with the cylinder body 81 so as to protrude from the outer wall of the end of the cylinder body 81 on the valve seat 15 side to the outside in the radial direction.

In the present embodiment, when the needle 40 is closed, that is, for example, when the energization to the coil 60 is stopped and the seal portion 43 is in contact with the valve seat 15 (see FIG. 10), the out-cylinder protruding portion 83. The cylinder outer upper surface 831 that is the surface of the movable core 50 is in contact with the guide lower surface 902 of the guide member 90. Here, the cylinder member 80 has the cylinder upper surface 831 pressed against the guide lower surface 902. The guide lower surface 902 regulates the movement of the cylindrical member 80 in the valve closing direction, and at the same time, the distance between the fixed core upper surface 201 and the cylindrical upper surface 801 in the valve closed state, that is, between the fixed core upper surface 201 and the movable core lower surface 502. Can be maintained at a predetermined distance.
In this embodiment, the cylinder upper surface 831 is located on the same plane as the cylinder upper surface 821.

  The configuration of the fifth embodiment is the same as that of the first embodiment except for the points described above. Therefore, the fifth embodiment has an effect similar to that of the first embodiment, and also has an effect of keeping the distance between the fixed core upper surface 201 and the movable core lower surface 502 in a closed state at a predetermined size. it can.

(Sixth embodiment)
FIG. 11 shows a part of a fuel injection device according to a sixth embodiment of the present invention. The sixth embodiment differs from the fifth embodiment in the shapes of the cylindrical member 80 and the guide member 90.

  In the sixth embodiment, the cylinder upper surface 831 is located on the valve seat 15 side with respect to the cylinder inner upper surface 821. Accordingly, the cylinder main body 81 and the in-cylinder protrusion 82 are formed to have a longer axial length than the fifth embodiment. Further, the guide main body 91 of the guide member 90 is also formed to have a longer axial length than the fifth embodiment. Therefore, compared with 5th Embodiment, the sliding length of the guide member 90 and the cylinder member 80 can be lengthened. Therefore, the posture of the cylindrical member 80 when reciprocating can be made more stable.

  The configuration of the sixth embodiment is the same as that of the fifth embodiment except for the points described above. Therefore, the sixth embodiment can achieve the same effects as the fifth embodiment and the effect of further stabilizing the posture of the cylindrical member 80 during the reciprocating movement.

(Seventh embodiment)
FIG. 12 shows a part of the fuel injection device according to the seventh embodiment of the present invention. The seventh embodiment differs from the fifth embodiment in the shapes of the cylindrical member 80 and the flange portion 44.

  In the seventh embodiment, the cylinder upper surface 821 is positioned on the valve seat 15 side with respect to the cylinder outer upper surface 831. Accordingly, the cylinder main body 81 and the out-cylinder protruding portion 83 are formed to have a longer axial length than the fifth embodiment. Moreover, the collar part 44 is also formed in the axial direction long compared with 5th Embodiment. Therefore, compared with 5th Embodiment, the sliding length of the cylinder member 80 and the collar part 44 can be lengthened. Therefore, the postures of the flange portion 44 and the second needle body 42 during the reciprocating movement can be made more stable.

  The configuration of the seventh embodiment is the same as that of the fifth embodiment except for the points described above. Therefore, the seventh embodiment can achieve the same effects as the fifth embodiment and the effect of making the posture of the flange portion 44 and the second needle body 42 reciprocating more stable.

(Eighth embodiment)
FIG. 13 shows a fuel injection device according to an eighth embodiment of the present invention.
The eighth embodiment differs from the first embodiment in that it further includes a movement restricting unit 4.

  The movement restricting portion 4 is formed in a substantially cylindrical shape with a metal such as stainless steel. The movement restricting portion 4 is provided such that one end surface abuts on the locking surface 33 of the introduction pipe 30 and the outer wall is fitted to the inner wall of the introduction pipe 30. The movement restricting portion 4 can be in contact with the outer edge portion of the movable core upper surface 501 at the end face on the valve seat 15 side. The movement restricting portion 4 can restrict the movement of the movable core 50 in the valve closing direction when the end face on the valve seat 15 side comes into contact with the outer edge portion of the movable core upper surface 501. Therefore, it is possible to suppress excessive movement of the movable core 50 in the valve closing direction when the needle 40 is closed, that is, when the needle 40 transitions from the valve opening state to the valve closing state. Thereby, responsiveness can be improved more.

  The configuration of the eighth embodiment is the same as that of the first embodiment except for the points described above. Therefore, 8th Embodiment can show | play the effect similar to 1st Embodiment, and can show the effect which suppresses the excessive movement to the valve closing direction of the movable core 50, and improves responsiveness.

(Ninth embodiment)
FIG. 14 shows a fuel injection device according to the ninth embodiment of the present invention.
The ninth embodiment differs from the first embodiment in that it further includes a spring 74 as a needle urging member.

  The needle 40 further has a locking collar portion 46. The locking collar portion 46 is formed in a substantially annular shape. The locking collar portion 46 is provided on the outer wall of the second needle body 42 between the locking surface 33 of the introduction pipe 30 and the concave portion 51 of the movable core 50. The locking collar portion 46 is provided so that its inner edge fits into the outer wall of the second needle body 42. As a result, the locking collar 46 cannot be moved relative to the second needle body 42.

  The spring 74 is, for example, a coil spring, and is provided between the locking collar portion 46 and the locking surface 33. One end of the spring 74 is locked to the locking collar 46 and the other end is locked to the locking surface 33. The spring 74 is compressed in the axial direction by the locking collar portion 46 and the locking surface 33. Therefore, the spring 74 biases the second needle body 42 in the valve opening direction. Thereby, the collar lower surface 442 is pressed against the in-cylinder upper surface 821 of the cylinder member 80.

  In the present embodiment, by providing the spring 74, when the needle 40 is closed, that is, for example, when energization to the coil 60 is stopped and the seal portion 43 is in contact with the valve seat 15 (see FIG. 14). ), A gap S1 having a predetermined size can be formed between the movable core lower surface 502 and the flange upper surface 441. Further, the spring 74 can restrict excessive movement of the second needle body 42 in the valve closing direction such as after the needle 40 is closed.

  The ninth embodiment is the same as the first embodiment except for the points described above. Therefore, the ninth embodiment has the same effect as the first embodiment, and a gap S1 having a predetermined size is formed between the movable core lower surface 502 and the collar upper surface 441, and the second needle body 42 An effect of restricting excessive movement in the valve closing direction can be achieved.

(Other embodiments)
In another embodiment of the present invention, the tubular member 80 may not have the in-cylinder protruding portion 82.
In another embodiment of the present invention, the guide member 90 may not be provided. In another embodiment of the present invention, the guide member 90 and the cylindrical member 80 may not be provided. In this case, the spring 72 as the second urging member may be provided so that one end is locked to the bottom surface of the recess 21 of the fixed core 20 and the other end is locked to the movable core lower surface 502.
In another embodiment of the present invention, the cylindrical member 80 is made immovable relative to the movable core 50 by, for example, welding the end of the cylindrical body 81 on the movable core 50 side to the movable core lower surface 502. It may be provided.

  In another embodiment of the present invention, the second needle body 42 may be formed integrally with the first needle body 41. In this case, the inner diameter of the hole portion 200 of the fixed core 20 is made larger than the outer diameter of the flange portion 44, or the flange portion 44 is formed separately from the second needle body 42, and the second needle body 42 is formed in the hole portion 200. The hook portion 44 may be fitted to the second needle body 42 after being inserted into the second needle body 42.

Further, in the above-described eighth embodiment, the example in which the fuel injection device includes the spring 73 as the movable core urging member and the movement restriction unit 4 has been described. On the other hand, in another embodiment of the present invention, the spring 73 may be omitted. Further, the movement restricting portion 4 may be formed integrally with the introduction pipe 30.
Moreover, in other embodiment of this invention, the nozzle cylinder part 11 and the nozzle cylinder part 12 may be integrally formed with the same material.
Further, in another embodiment of the present invention, the magnetic diaphragm portion 2 is not limited to being formed by a cylindrical nonmagnetic member, and for example, the thickness of a part of the cylindrical magnetic material in the axial direction is reduced. May be formed.

The present invention is not limited to injecting high-pressure fuel, but may be used to inject low-pressure fuel.
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.
Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 Fuel injection apparatus, 10 Nozzle, 11, 12 Nozzle cylinder part, 13 Nozzle bottom part, 14 Injection hole, 15 Valve seat, 100 Fuel passage, 20 Fixed core, 40 Needle, 41 1st needle body, 42 2nd needle body, 43 seal part, 44 collar part, 441 collar part upper surface, 442 collar part lower surface, 50 movable core, 502 movable core bottom surface, 60 coils, 71 spring (first biasing member), 72 spring (second biasing member)

Claims (15)

A nozzle cylinder (11, 12) having a fuel passage (100) on the inside, a nozzle bottom (13) blocking one end of the nozzle cylinder, and penetrating through the nozzle bottom, the fuel in the fuel passage is injected. And a nozzle (10) having a valve seat (15) formed annularly around the nozzle hole on the surface of the nozzle bottom opposite to the nozzle cylinder,
A fixed core (20) provided on the opposite side of the nozzle bottom of the nozzle cylinder,
A rod-shaped first needle body (41), a seal portion (43) formed at one end of the first needle body so as to be able to contact the valve seat, and the side opposite to the valve seat with respect to the first needle body A rod-shaped second needle body (42) provided on the flange, a flange (44) provided on the radially outer side of the second needle body, and a flange formed on the opposite side of the flange to the valve seat An upper surface (441) and a flange lower surface (442) formed on the valve seat side of the flange, and when the seal portion is separated from the valve seat or abuts on the valve seat, the nozzle hole is formed. A needle (40) for opening and closing;
A movable core lower surface (502) provided on the opposite side of the fixed core to the nozzle so as to be relatively movable with respect to the fixed core and the needle, and capable of contacting or separating from the upper surface of the flange portion. A movable core (50);
When energized, the movable core is sucked toward the fixed core, the lower surface of the movable core is brought into contact with the upper surface of the flange portion, and the needle is moved in a valve opening direction that is a direction in which the seal portion is separated from the valve seat. A coil (60) that can be moved;
A first biasing member (71) capable of biasing the first needle body in a valve closing direction, which is a direction in which the seal portion abuts the valve seat;
A second biasing member (72) capable of biasing the movable core in the valve closing direction;
A fuel injection device (1) comprising:   2. The fuel injection device according to claim 1, wherein the movable core can form a gap (S <b> 1) between the lower surface of the movable core and the upper surface of the flange when the seal portion is in contact with the valve seat. .   The cylinder member (80) which is provided in the said valve seat side of the said movable core so that it can move relatively with respect to a said 2nd needle main body, and further has a cylindrical cylinder main body (81). Fuel injection device.   The cylinder member is formed on a side opposite to the valve seat of the in-cylinder protruding part (82) protruding inward in the radial direction from the inner wall of the cylinder main body, and is in contact with the lower surface of the flange part The fuel injection device according to claim 3, further comprising an in-cylinder upper surface (821) that can be separated from the lower surface of the flange portion.   5. The fuel injection device according to claim 3, wherein the second urging member is capable of urging the movable core in the valve closing direction via the cylindrical member.   The fuel injection according to any one of claims 3 to 5, wherein the second urging member is capable of urging the second needle body in the valve closing direction via the cylindrical member and the flange portion. apparatus. A guide member (90) provided on the inner wall of the fixed core, the inner wall having a cylindrical guide body (91) slidable with the outer wall of the cylinder body;
The fuel injection device according to any one of claims 3 to 6, wherein an inner wall of the cylinder body is slidable with an outer wall of the flange portion.   The guide member further includes a guide outer protrusion (92) that protrudes radially outward from an outer wall of the guide main body and can abut on a surface of the fixed core opposite to the valve seat. The fuel injection device described in 1.   The guide member further includes an in-guide protrusion (94) protruding inward in the radial direction from an inner wall of the guide body and capable of contacting the valve seat side surface of the cylindrical member. The fuel injection device described.   The said cylinder member further has a cylinder outside protrusion part (83) which protrudes to a radial direction outer side from the outer wall of the said cylinder main body, and can contact | abut to the said valve seat side surface of the said guide member. The fuel injection device according to any one of claims.   The fuel injection device according to any one of claims 3 to 10, wherein the cylindrical member is provided so as to be movable relative to the movable core.   The fuel injection device according to any one of claims 1 to 11, further comprising a movable core urging member (73) capable of urging the movable core in the valve opening direction.   The second needle body is formed separately from the first needle body, and a gap (S2) can be formed between the second needle body and the first needle body. The fuel injection device described in 1.   The fuel injection device according to any one of claims 1 to 13, further comprising a movement restricting portion (4) capable of restricting movement of the movable core in the valve closing direction.   The fuel injection device according to any one of claims 1 to 14, further comprising a needle biasing member (74) capable of biasing the second needle body in the valve opening direction.

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