JP6635212B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve that injects fuel to an internal combustion engine.

  2. Description of the Related Art Conventionally, there has been known a fuel injection valve having a configuration in which an urging member is provided on a valve seat side of a movable core into which a needle is inserted in order to increase the response of the needle. In the fuel injection valve of Patent Literature 1, a movable core is provided on a valve seat side of a collar portion of a needle. A first biasing member that biases the needle and the movable core in the valve closing direction is provided on a side of the needle flange opposite to the valve seat. In addition, a second biasing member that biases the movable core and the needle in the valve opening direction is provided on the valve seat side of the movable core. In the case of the fuel injection valve having such a configuration, after the movable urging member contracts the second urging member, the movable core is again pushed back by the second urging member, and collides with the collar of the valve-closed needle to cause the secondary core to move. The valve may open.

  Further, in the case of the fuel injection valve described in Patent Document 2, an acceleration distance is provided between the movable core and the first flange (the needle flange). However, the fuel injection valve described in Patent Literature 2 needs to weld the first flange and the second flange to the needle and weld the sleeve to the movable core. For this reason, the number of parts and the number of welding locations increase, and assembly becomes complicated. In addition, the welded portion between the first flange and the needle may be affected by thermal deformation or the like, and the acceleration distance may change.

JP 2009-150346A Table 2008-506875

  The present invention has been made in view of the above-described problem, and an object of the present invention is to provide a fuel injection valve which can suppress a secondary valve opening while improving a valve opening speed and can easily manage a clearance. It is in.

The fuel injection valve of the present invention includes a needle (30), a movable core (440), a fixed core (60), a movable member (580), a spring (80), a coil (70), and a lifting unit. The needle opens and closes an injection hole (11) through which fuel is injected at a portion (31) on one end side. The movable core is provided so as to be relatively movable with respect to the needle. The fixed core is provided on the opposite side of the movable core from the injection hole, and has a through hole in the axial direction of the needle.
The movable member has a first contact portion (542) that can abut in the axial direction on a second surface (331), which is a surface opposite to the injection hole of the needle, and can abut on the movable core in the axial direction. A second contact portion (542). In the movable member, when the injection hole is closed by the needle, the first contact portion contacts the second surface, and the second contact portion contacts the movable core. The spring urges the movable member toward the injection hole. When electric power is supplied to the coil, a magnetic force is generated, and the coil attracts the movable core toward the fixed core. The lifting unit comes into contact with the needle when power is supplied to the coil, and raises the needle in the valve opening direction. The needle has a third surface, which is a surface formed on the injection hole side so as to come into contact with the lifting portion when power is supplied to the coil. In a state where the first contact portion and the second surface are in contact with each other, a gap is formed between the lifting portion and the third surface. The outer diameter of the movable member is larger than the inner diameter of the through hole. The end surface of the movable member opposite to the injection hole faces the end surface of the fixed core on the injection hole side.

  In the fuel injection valve of the present invention, when the injection hole is closed by the needle, that is, when the first contact portion and the second surface are in contact with each other, the movable member has the third surface of the needle and the lifting portion. A gap is formed between them. Thus, when the movable core is sucked in the valve opening direction, the lifting unit accelerates a predetermined distance and then collides with the third surface of the needle. Therefore, the fuel injection valve of the present invention can quickly open the needle using energy at the time of collision, and can improve the valve opening speed.

  Further, when the injection hole is closed by the needle, a gap is formed between the third surface of the needle and the raising portion, so that the raising portion that unexpectedly moves in the valve opening direction after closing the valve is closed. Collision with the third surface of the existing needle can be suppressed. Therefore, it is possible to suppress the occurrence of the secondary valve opening due to the lifting portion that moves in the valve opening direction after the valve is closed.

  Further, the distance of the gap is determined by the distance between the second surface and the third surface of the needle and the distance between the first contact portion and the lifting portion of the movable member. Therefore, the distance between the gaps can be adjusted by changing the distance between the second surface and the third surface of the needle, or the distance between the first contact portion and the lifting portion of the movable member. Therefore, clearance management can be easily performed.

FIG. 1 is a schematic cross-sectional view showing the entire fuel injection valve according to a first embodiment of the present invention. FIG. 1 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to a first embodiment of the present invention. FIG. 2 is a schematic sectional view showing a method of assembling the fuel injection valve according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the operation of the fuel injection valve according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the operation of the fuel injection valve according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the operation of the fuel injection valve according to the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to a second embodiment of the present invention. FIG. 7 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to a third embodiment of the present invention. FIG. 9 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to a fourth embodiment of the present invention. FIG. 13 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to a fifth embodiment of the present invention. FIG. 14 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to a sixth embodiment of the present invention. FIG. 14 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to a seventh embodiment of the present invention. FIG. 14 is a schematic cross-sectional view illustrating the operation of a fuel injection valve according to a seventh embodiment of the present invention. FIG. 19 is a schematic cross-sectional view illustrating a main part of a fuel injection valve according to an eighth 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 valve according to a first embodiment of the present invention. The fuel injection valve 1 is used for an internal combustion engine (not shown) and injects and supplies fuel to the internal combustion engine.

The fuel injection valve 1 includes a housing 20, a nozzle portion 10, a fixed core 60, a movable core 40, a needle 30, a movable plate 50, a first spring 80, a second spring 90, a coil 70, and the like.
As shown in FIG. 1, the housing 20 includes a first tubular member 21, a second tubular member 22, a third tubular member 23, an outer peripheral member 25, and a resin mold 26. The first tubular member 21, the second tubular member 22, and the third tubular member 23 are all formed in a substantially cylindrical shape, and become coaxial in the order of the first tubular member 21, the second tubular member 22, and the third tubular member 23. Arranged and connected to each other. The outer peripheral member 25 is in contact with the outer peripheral surfaces of the first cylindrical member 21 and the third cylindrical member 23.

  The first tubular member 21, the third tubular member 23, and the outer peripheral member 25 are made of a magnetic material such as ferrite stainless steel, and have been subjected to a magnetic stabilization process. On the other hand, the second cylindrical member 22 is formed of a nonmagnetic material such as austenitic stainless steel.

  The nozzle portion 10 is provided at an end of the first cylindrical member 21 of the housing 20 opposite to the second cylindrical member 22. 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.

  In the present embodiment, the nozzle unit 10 is formed in a substantially circular plate shape. An injection hole 11 penetrating the nozzle portion 10 in the thickness direction is formed at the center of the nozzle portion 10. An annular valve seat 12 is formed on one surface of the nozzle portion 10 so as to surround the injection hole 11. The nozzle portion 10 is connected to the first cylindrical member 21 such that the side wall is fitted to the inner wall of the first cylindrical member 21. The fitting portion between the nozzle portion 10 and the first cylindrical member 21 is welded.

  The fixed core 60 is formed in a substantially cylindrical shape from a magnetic material such as ferrite stainless steel. The fixed core 60 has been subjected to a magnetic stabilization process. The fixed core 60 is provided inside the housing 20. The fixed core 60 and the third cylindrical member 23 of the housing 20 are welded.

The needle 30 is formed in a rod shape from a metal such as a martensitic stainless steel, for example.
The needle 30 is accommodated in the housing 20 so as to be able to reciprocate in the axial direction. At the end of the main body 32 as a rod-shaped “needle main body” of the needle 30 on the nozzle unit 10 side, a seal part 31 as a “part on one end side of the needle” that can abut on the valve seat 12 is formed. . In addition, the needle 30 has a flange portion 33 formed so as to expand from the end opposite to the nozzle portion 10 toward the inner wall 24 of the housing 20. In the present embodiment, the flange 33 is formed in a substantially disk shape. The needle 30 opens and closes the injection hole 11 when the seal portion 31 is separated (separated) from the valve seat 12 or abuts (seated) on the valve seat 12. Hereinafter, the direction in which the needle 30 is separated from the valve seat 12 is referred to as a valve opening direction, and the direction in which the needle 30 contacts the valve seat 12 is referred to as a valve closing direction. The flange 33 side of the main body 32 is formed in a hollow cylindrical shape, and a hole 34 connecting the inner wall 321 and the outer wall 322 of the main body 32 is formed.

  The movable core 40 is formed in a substantially cylindrical shape by a magnetic material such as ferrite stainless steel. The movable core 40 has been subjected to a magnetic stabilization process. Here, a hard coating is formed on the end face 41 of the movable core 40 by a hard coating process.

  The movable core 40 is provided inside the housing 20 so as to be able to reciprocate between the fixed core 60 and the nozzle unit 10. A through hole 44 is formed at the center of the movable core 40. The inner wall 441 of the through hole 44 of the movable core 40 and the outer wall 322 of the main body 32 of the needle 30 are slidable, and the outer wall 42 of the movable core 40 and the inner wall 24 of the housing 20 are slidable. Thereby, the movable core 40 can reciprocate inside the housing 20 while sliding with the needle 30 and the housing 20.

  The movable core 40 has a housing recess 45 formed on the end surface 41 on the fixed core 60 side so as to be annularly expanded radially outward from the inner wall 441 of the through hole 44. In addition, the movable core 40 has, on the end surface 41 on the fixed core 60 side, a fitting groove portion 46 formed so as to annularly expand radially outward from an end of the side wall 451 of the housing recess 45 opposite to the bottom wall 452. . The accommodating concave portion 45 accommodates the flange portion 33 of the needle 30, and the fitting groove portion 46 is fitted with a movable plate 50 described later.

  The movable plate 50 is formed of a metal such as a martensitic stainless steel into a disk shape having a diameter larger than that of the housing recess 45, and has a hole 51 in the center. The movable plate 50 is provided on the opposite side of the movable core 40 from the nozzle unit 10 so as to be able to abut on the movable core 40 and the flange of the needle 30. In the case of the present embodiment, the movable plate 50 is provided so as to be able to fit into the fitting groove portion 46.

  The coil 70 is formed in a substantially cylindrical shape, and is provided so as to surround the housing 20, particularly, radially outside the second cylindrical member 22 and the third cylindrical member 23, and includes the first cylindrical member 21, the second cylindrical member 22, and the third cylindrical member 22. A resin mold portion 26 is filled between the cylindrical member 23 and the outer peripheral member 25. The resin mold portion 26 has a connector portion (not shown) in which a part in the circumferential direction protrudes outward from the outer peripheral member 25 and in which an energization terminal (not shown) electrically connected to the coil 70 is disposed. Has formed. The coil 70 generates a magnetic force when electric power is supplied through the connector section.

  When a magnetic force is generated in the coil 70, a magnetic circuit is formed in the fixed core 60, the movable core 40, the first tubular member 21, the third tubular member 23, and the outer peripheral member 25. Thereby, the movable core 40 is sucked by the fixed core 60. At this time, since the bottom wall 452 of the housing recess 45 abuts on the flange 33 of the needle 30, the needle 30 moves together with the movable core 40 toward the fixed core 60, that is, in the valve opening direction. Thereby, the seal part 31 is separated from the valve seat 12, and the injection hole 11 is opened. Further, the movable core 40 is restricted from moving in the valve opening direction when the end face 41 abuts on the fixed core 60.

  The first spring 80 is provided such that one end thereof is in contact with a spring-side end surface 52 of the movable plate 50 opposite to the needle 30. The other end of the first spring 80 is in contact with one end of an adjusting pipe 61 press-fitted and fixed inside the fixed core 60. The first spring 80 has a force that extends in the axial direction. Thus, the first spring 80 urges the movable core 50 and the needle 30 in the valve closing direction by urging the movable plate 50.

  The second spring 90 is provided such that one end thereof is in contact with a bottom surface of a groove 431 formed on the end surface 43 of the movable core 40. The other end of the second spring 90 is in contact with an annular step surface 211 formed inside the first cylindrical member 21 of the housing 20. The second spring 90 has a force that extends in the axial direction. As a result, the second spring 90 biases the movable plate 40 toward the fixed core 60 by biasing the movable core 40.

  In the present embodiment, the urging force of the first spring 80 is set to be larger than the urging force of the second spring 90. Therefore, in a state where electric power is not supplied to the coil 70, that is, in a state where the fuel injection valve 1 is not operated (hereinafter, referred to as “non-operated state”), the seal portion 31 of the needle 30 is attached to the valve seat 12. , That is, a valve closed state.

  As shown in FIG. 2, in a non-operating state of the fuel injection valve 1 of the present embodiment, the urging force of the first spring 80 and the second spring 90 causes the needle-side end surface 53 of the movable plate 50 on the needle 30 side, The end surface 331 of the needle 33 as the “needle second surface” and the bottom wall 461 of the fitting groove 46 of the movable core 40 abut. Here, assuming that the axial length of the flange 33 is L1, and the axial distance between the needle-side end face 53 of the movable plate 50 on the needle 30 side and the bottom wall 452 of the accommodation recess 45 is L2. The movable plate 50, the accommodation recess 45, and the fitting groove 46 are formed so as to satisfy the relationship of L1 <L2.

The axial distance between the end surface 332 of the flange 33 as the “needle first surface” and the bottom wall 452 of the housing recess 45 is G1, and the distance between the end surface 41 of the movable core 40 and the movable core 40 side of the fixed core 60 is defined as G1. Assuming that the axial distance from the end face is G2, the flange 33, the movable plate 50, the accommodation recess 45, the fitting groove 46, the movable core 40, and the fixed core 60 are G1 <G2, and G1 = L2-L1. Is provided so as to satisfy the following relationship.
A substantially cylindrical fuel introduction pipe 62 is press-fitted and welded to an end of the third cylindrical member 23 opposite to the second cylindrical member 22.

  The fuel flowing from the inlet of the fuel introduction pipe 62 is supplied to the fixed core 60, the adjusting pipe 61, the hole 51 of the movable plate 50, the inside of the body 32 of the needle 30, the hole 34 of the needle 30, the first cylindrical member 21 and the needle. 30, and between the seal portion 31 of the needle 30 and the valve seat 12 of the nozzle portion 10, and is guided to the injection hole 11. That is, the fuel passage 100 through which the fuel flows is formed inside the housing 20.

A method for assembling the fuel injection valve 1 according to the present embodiment will be described with reference to FIG.
First, as shown in FIG. 3A, the needle 30 is inserted into the through hole 44 of the movable core 40, and the flange 33 is housed in the housing space of the housing recess 45.
Next, as shown in FIG. 3B, the movable plate 50 is fitted into the fitting groove 46 of the movable core 40, and one end of the first spring 80 is fitted to the spring-side end face 52 of the movable plate 50 opposite to the needle 30. Abut. Then, one end of the second spring 90 is brought into contact with the bottom surface of the groove 431 of the movable core 40 from the seal portion 31 side of the needle 30 so that the needle 30 is located inside the second spring 90.

As shown in FIG. 3C, the combined first spring 80, movable plate 50, needle 30, movable core 40, and second spring 90 are inserted into the housing 20, and the other end of the second spring 90 is connected to the housing. 20 is brought into contact with the step surface 211.
Finally, the fixed core 60 and the adjusting pipe 61 are pressed into the housing 20, and the other end of the first spring 80 is brought into contact with the adjusting pipe 61. Here, the position of the fixed core 60 is adjusted so as to satisfy the relationship of G1 <G2. Further, the position of the adjusting pipe 61 is adjusted so that the urging force of the first spring 80 is larger than the urging force of the second spring 90.

Next, the operation of the fuel injection valve 1 according to the present embodiment will be described with reference to FIGS.
As shown in FIG. 4A, in a non-operating state, the first spring 80 urges the movable plate 50 to urge the needle 30 in the valve closing direction. Further, the second spring 90 urges the movable core 40 toward the fixed core 60. Here, the needle-side end surface 53 of the movable plate 50 on the needle 30 side is in contact with the end surface 331 of the flange 33 of the needle 30 and the bottom wall 461 of the fitting groove 46 of the movable core 40. At this time, the axial distance L2 between the needle-side end surface 53 of the movable plate 50 and the bottom wall 452 of the housing recess 45 is greater than the axial length L1 of the flange 33. The predetermined axial distance G1 between the end surface 332 of the flange 33 and the bottom wall 452 of the housing recess 45 is smaller than the axial distance G2 between the movable core 40 and the fixed core 60.
At this time, the injection hole 11 of the nozzle portion 10 is in a closed state when the seal portion 31 of the needle 30 is seated on the valve seat 12.

When a current is supplied to the coil 70, the movable core 40 is attracted by the fixed core 60 and moves to the fixed core 60 side, as shown in FIG. Here, the movable plate 50 is pushed by the movable core 40 and moves toward the first spring 80 against the urging force of the first spring 80. Further, the movable core 40 accelerates by a predetermined distance G1 and collides with the end surface 332 of the collar portion 33 of the needle 30 with kinetic energy corresponding to the acceleration distance.
At this time, the needle 30 rapidly moves in the valve opening direction, and the seal portion 31 separates from the valve seat 12. Therefore, the injection hole 11 of the nozzle part 10 opens rapidly. The fuel flowing from the fuel introduction pipe 62 flows through the fuel passage 100 and is injected from the injection hole 11.

As shown in FIG. 4C, when the movable core 40 and the fixed core 60 collide, the movement of the movable core 40 is restricted.
At this time, the lift amount of the needle 30 is maximized, and the injection hole 11 of the nozzle unit 10 is in the maximum open state.

When the current supply to the coil 70 is stopped, the attractive force generated by the coil 70 decreases. Here, immediately after the current supply to the coil 70 is stopped, as shown in FIG. 5A, the state in which the movable core 40 and the fixed core 60 are in contact with each other is maintained for a short time.
When the suction force generated by the coil 70 falls below the valve-opening holding force, as shown in FIG. 5B, the movable plate 50, the movable core 40, and the needle 30 move in the valve closing direction.

  The movement of the needle 30 is stopped when the seal portion 31 contacts the valve seat 12 of the nozzle portion 10. As shown in FIG. 5C, the movable plate 50 stops moving by contacting the end surface 331 of the needle 30, and is urged by the first spring 80 toward the needle 30.

Thereafter, as shown in FIG. 6A, the movable core 40 presses the second spring 90 toward the nozzle unit 10 by inertia.
After being pressed to the limit, the pressed second spring 90 moves the movable core 40 toward the movable plate 50. As shown in FIG. 6B, the movable core 40 is configured such that the bottom wall 452 of the housing recess 45 does not contact the end surface 332 of the flange 33 of the needle 30 and the bottom wall 461 of the fitting groove 46 is It comes into contact with the needle side end face 53. Then, the movable core 40 moves toward the step surface 211 again by the urging force of the first spring 80.

  The movable core 40 vibrates until there is no more kinetic energy, and finally returns to a non-operating state as shown in FIG.

  As described above, in the present embodiment, when the movable core 40 and the movable plate 50 are in contact with each other, the relationship of L1 <L2 is established between the flange 33, the movable plate 50, the accommodation recess 45, and the fitting groove 46. It is formed to satisfy. Thus, a gap having a predetermined axial distance G1 is formed between the end surface 332 of the flange 33 and the bottom wall 452 of the housing recess 45. Therefore, when the movable core 40 is attracted in the valve opening direction by the magnetic force of the coil 70 to which power is supplied, the movable core 40 accelerates by a predetermined distance G1 and then collides with the collar 33 of the needle 30. Therefore, the needle 30 can be quickly opened using the energy at the time of collision.

  Further, in the present embodiment, since a gap of a predetermined distance G1 is formed between the end surface 332 of the flange 33 and the bottom wall 452 of the housing recess 45, the second spring 90 is pushed back by the second spring 90 after being pressed. The movable core 40 is prevented from hitting the flange 33 of the needle 30 that is closed. Therefore, occurrence of secondary valve opening due to the movable core 40 pushed back by the second spring 90 can be suppressed.

  Further, the predetermined distance G1 is determined by the axial length L1 of the flange 33 and the axial distance L2 between the movable plate 50 and the bottom wall 452 of the housing recess 45. Therefore, the predetermined distance G1 can be adjusted by changing the axial length L1 of the flange 33 or the axial distance L2 between the movable plate 50 and the bottom wall 452 of the housing recess 45. Therefore, clearance management can be easily performed.

  In the present embodiment, the movable core 40 has, on the end surface 41 on the fixed core 60 side, an insertion groove 46 into which the movable plate 50 can be inserted. Therefore, when the movable plate 50 and the movable core 40 come into contact with each other, it is possible to suppress the movable plate 50 from being separated from the end face 41 of the movable core 40.

(2nd Embodiment)
FIG. 7 shows a fuel injection valve according to this embodiment. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 7, on the fixed core 60 side of the movable core 420 of the fuel injection valve 2, only a housing recess 450 having a larger diameter than the through hole 44 is formed. The movable plate 50 is provided so as to be able to contact the flange 33 of the needle 30 and the end surface 421 of the movable core 420 on the fixed core 60 side.
With such a configuration, in the present embodiment, the needle 30 can be quickly opened as in the above-described embodiment. Then, occurrence of secondary valve opening by the movable core 40 pushed back by the second spring 90 can be suppressed.

(Third embodiment)
FIG. 8 shows the fuel injection valve of the present embodiment. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 8, the peripheral edge 533 of the movable plate 530 of the fuel injection valve 3 is formed in a tapered shape whose diameter increases from the needle 30 side toward the first spring 80 side. That is, the peripheral edge 533 of the movable plate 530 is formed in a tapered shape such that the spring-side end surface 531 on the first spring 80 side has a larger diameter than the needle-side end surface 532 on the needle 30 side.

  Further, the opening peripheral edge 454 of the housing recess 45 of the end surface 41 of the movable core 430 on the fixed core 60 side is formed in a tapered shape so that the diameter increases from the bottom wall 452 side of the housing recess 45 toward the fixed core 60 side. . In the present embodiment, when the movable plate 530 and the movable core 430 come into contact with each other, the peripheral edge 533 of the movable plate 530 and the opening peripheral edge 454 of the housing recess 45 face and contact with each other.

  In the present embodiment, since the peripheral edge 533 of the movable plate 530 is formed in a tapered shape, it is possible to prevent the movable plate 530 from being displaced from the movable core 40. Further, since the opening peripheral edge 454 of the housing recess 45 of the movable core 430 is formed in a tapered shape, the effect of suppressing the displacement of the movable plate 530 and the movable core 40 can be enhanced.

(Fourth embodiment)
FIG. 9 shows the fuel injection valve of the present embodiment. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 9, the outer diameter of the movable plate 540 of the fuel injection valve 4 is formed larger than the inner diameter of the fixed core 60. Further, the height of the peripheral edge 543 of the movable plate 540 in the axial direction is formed larger than the height of the side wall 465 of the fitting groove 464 of the movable core 440 in the axial direction. Therefore, in a state where the needle-side end surface 542 of the movable plate 540 and the bottom wall 462 of the fitting groove portion 464 are in contact with each other, the spring-side end surface 541 of the movable core 440 on the fixed core 60 side is the end surface of the movable core 440 on the fixed core 60 side. It is located on the fixed core 60 side of 442.

  In the present embodiment, the outer diameter of the movable plate 540 is formed to be larger than the inner diameter of the fixed core 60, and the height in the axial direction of the peripheral edge 543 of the movable plate 540 is larger than the height in the axial direction of the side wall 465 of the fitting groove 464. It is formed. As a result, the fixed core 60 contacts only the movable plate 540 without contacting the movable core 440. For this reason, the hard processing may be performed on the surface of the movable plate 540 instead of the movable core 440. Therefore, as compared with the above embodiment, the movable core 440 can be formed in a simple shape, and the cost can be reduced.

(Fifth embodiment)
FIG. 10 shows a fuel injection valve according to this embodiment. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 10, on the fixed core 60 side of the movable core 420 of the fuel injection valve 5, only a housing recess 450 having a diameter larger than the through hole 44 is formed. The outer diameter of the movable plate 540 is formed to be larger than the inner diameter of the fixed core 60.
With such a configuration, in the present embodiment, the movable core 440 can be formed in a simpler shape than in the fourth embodiment, and the cost can be further reduced.

(Sixth embodiment)
FIG. 11 shows a fuel injection valve of the present embodiment. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 11, the movable core 460 of the fuel injection valve 6 has a plurality of first holes 47 formed in the axial direction. The plurality of first holes 47 are formed symmetrically with respect to the axis of the movable core 460. The first hole 47 connects the bottom wall 457 of the housing recess 456 and the end surface 463 of the movable core 460 on the nozzle unit 10 side.

  The movable plate 560 as a “movable member” has a plurality of second holes 563 penetrating through the movable plate 560 in the thickness direction at positions where the movable plate 560 contacts the flange portion 33. The second hole 563 connects the spring-side end surface 561 of the movable plate 560 on the fixed core 60 side to the needle-side end surface 562 of the needle 30.

  In the present embodiment, by forming the plurality of first holes 47 in the movable core 460, when the flange portion 33 of the needle 30 and the bottom wall 457 of the accommodation concave portion 456 separate from each other, the sticking due to the ringing force is prevented. Can be suppressed. In addition, by forming the plurality of second holes 563 in the movable plate 560, when the movable plate 560 and the flange 33 are separated from each other after contact, the sticking due to the ringing force can be suppressed.

(Seventh embodiment)
FIG. 12 shows the fuel injection valve of the present embodiment. Components that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.
FIG. 12 is a schematic cross-sectional view showing a closed state of the fuel injection valve 7. As shown in FIG. 12, a locking portion 35 is provided on the needle 30. The locking portion 35 is provided on the outer wall 322 of the main body 32 between the flange portion 33 and the seal portion 31 so as to protrude radially outward of the main body 32. Thus, the second spring 97 is provided between the movable core 40 and the locking portion 35 and urges the needle 30 in the valve closing direction via the locking portion 35.

Here, the operation when the fuel injection valve 7 of the present embodiment is opened will be described with reference to FIG.
As shown in FIG. 13A, in a non-operating state, the first spring 80 urges the movable plate 50 to urge the needle 30 in the valve closing direction. The second spring 97 has one end in contact with the locking portion 35 and the other end in contact with the movable core 40, thereby urging the needle 30 in the valve closing direction, and moving the movable core 40 toward the fixed core 60. Energize.
At this time, the injection hole 11 of the nozzle portion 10 is in a closed state when the seal portion 31 of the needle 30 is seated on the valve seat 12.

When a current is supplied to the coil 70, the movable core 40 is attracted by the fixed core 60 and moves to the fixed core 60 side, as shown in FIG. Here, the movable plate 50 is pushed by the movable core 40 and moves toward the first spring 80 against the urging force of the first spring 80. The movable core 40 collides with the end surface 332 of the collar 33 of the needle 30 while having kinetic energy corresponding to the acceleration distance.
At this time, the needle 30 rapidly moves in the valve opening direction, and the seal portion 31 separates from the valve seat 12. Therefore, the injection hole 11 of the nozzle part 10 opens rapidly. The fuel flowing from the fuel introduction pipe 62 flows through the fuel passage 100 and is injected from the injection hole 11.

As shown in FIG. 13C, when the movable core 40 and the fixed core 60 collide, the movement of the movable core 40 in the axial direction is restricted.
At this time, the lift amount of the needle 30 is maximized, and the injection hole 11 of the nozzle unit 10 is in the maximum open state. The needle 30 is pressed in the valve closing direction by the fuel pressure f, and is pressed in the valve closing direction by the urging force of the second spring 97.

  In the present embodiment, the locking portion 35 is provided on the needle 30, and the second spring 97 urges the needle 30 via the locking portion 35. Thus, when the valve is held open as shown in FIG. 13C, the needle 30 is pressed in the valve closing direction by the fuel pressure f, and is pressed in the valve closing direction by the urging force of the second spring 97. For this reason, by suppressing the relative vibration of the needle 30 in the axial direction, the seating stability of the needle 30 can be enhanced.

(Eighth embodiment)
FIG. 14 shows the fuel injection valve of the present embodiment. Components that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.
As shown in FIG. 14, the fixed core 60 of the fuel injection valve 8 is formed in a cylindrical shape, and has an inner wall 63 and a nozzle-side end 64.

  The movable core 480 has a first concave portion 481 and a second concave portion 482 formed on the fixed core 60 side. The first recess 481 is formed to be recessed in the axial direction from the end surface 41 of the movable core 480, and has a first bottom 483. The second recess 482 is formed to be recessed in the axial direction from the first bottom 483 of the first recess 481, and has a second bottom 484 as a “core contact surface”. Further, the through hole 44 is formed in the second bottom portion 484.

  The movable plate 580 as a “movable member” has a spring-side end surface 581, a nozzle-side end surface 582, and a housing portion 583 formed on the nozzle-side end surface 582. The accommodation portion 583 is formed so as to be recessed in the axial direction from the nozzle side end surface 582, and has a bottom portion 584 as a “contactable portion” and a side wall portion 585 as an “extended portion”. A hole 586 is formed in the bottom 584.

In the case of the present embodiment, the movable plate 580 is guided by the inner wall 63 as the “fixed core inner wall surface” of the fixed core 60, and is provided so as to be able to reciprocate along the axial direction. Here, the axial distance d2 between the spring-side end face 581 of the movable plate 580 and the injection hole 11 and the axial distance d1 between the nozzle-side end 64 of the fixed core 60 and the injection hole 11 are: Equation 1 below is satisfied.
d1 <d2 Expression 1

  Further, the movable plate 580 is provided so that the nozzle-side end surface 582 and the first bottom portion 483 of the first concave portion 481 of the movable core 480 can abut. Thus, the end of the needle 30 inserted into the through hole 44 of the movable core 480 on the side of the flange portion 33 is housed in the housing portion 583 and is guided by the side wall portion 585 of the housing portion 583 to be axially guided. Is provided so as to be movable. Here, when the valve is closed, the end surface 331 of the flange 33 and the bottom 584 of the housing portion 583 abut. When the valve is opened, the end surface 332 of the flange 33 and the second bottom 484 of the second recess 482 abut.

  In the eighth embodiment, the movable plate 580 is guided by the inner wall 63 of the fixed core 60, and is provided so as to be able to reciprocate along the axial direction. The flange 33 of the needle 30 is guided by the side wall 585 of the housing 583 and housed in the housing 583 so as to be able to reciprocate in the axial direction. Thus, the needle 30 is guided by the inner wall 63 of the fixed core 60 via the movable plate 580. Such a configuration is advantageous in improving the coaxiality between the fixed core 60, the movable plate 580, and the needle 30, as compared with, for example, a configuration in which the needle 30 is guided by the inner wall 24 of the housing 20 via the movable core 480. It is. For this reason, in the reciprocating movement of the needle 30 in the axial direction, it is possible to suppress the inclination in the radial direction. Therefore, the stability of the reciprocating movement of the needle 30 in the axial direction can be improved.

  The movable plate 580 has an axial distance d2 between the spring-side end surface 581 of the movable plate 580 and the injection hole 11, and an axial distance d2 between the nozzle-side end 64 of the fixed core 60 and the injection hole 11. It is provided to be longer than the distance d1. Thereby, for example, when the valve is closed, the movable plate 580 can be prevented from being detached from the inner wall 63 of the fixed core 60. Therefore, the stability of the reciprocating movement of the needle 30 in the axial direction can be further improved.

(Ninth embodiment)
In the ninth embodiment of the present invention, the accommodation recess is formed on the needle side of the movable plate. In this case, the flange and the housing recess are formed such that the axial length of the needle flange is smaller than the axial distance between the end face of the movable core on the fixed core side and the bottom wall of the housing recess. .
(Other embodiments)
In the above-described embodiment, an example has been described in which the holes in the axial direction are formed in the movable plate and the movable core. On the other hand, in another embodiment of the present invention, an axial hole may be formed in the collar portion of the needle.
In the above-described embodiment, an example has been described in which the housing and the nozzle portion are formed separately. On the other hand, in another embodiment of the present invention, the housing and the nozzle portion may be formed integrally.
In the above-described embodiment, an example has been described in which the opening periphery of the housing recess is formed in a tapered shape. On the other hand, in another embodiment of the present invention, the periphery of the opening of the fitting groove may be formed in a tapered shape.
The present invention described above is not limited to the above embodiment, and can be applied to various embodiments without departing from the gist thereof.

8 Fuel injection valve 30 Needle 32 Body (needle body)
33 ... flange 331 ... end surface (needle second surface)
332: End face (needle first face)
480: movable core 484: second bottom (core contact surface)
580 ... Movable plate (movable member)
584... Bottom (contactable part)
585 ... side wall part (extended part)

Claims (1)

A needle (30) for opening and closing an injection hole (11) through which fuel is injected at a portion (31) at one end;
A movable core (440) provided to be relatively movable with respect to the needle;
A fixed core (60) provided on a side of the movable core opposite to the injection hole and having a through hole in an axial direction of the needle;
A first contact portion (542) axially capable of abutting on a second surface (331) of the needle opposite to the injection hole, and an axial contact with the movable core; A second contact portion (542), wherein when the injection hole is closed by the needle, the first contact portion contacts the second surface, and the second contact portion contacts the movable core. A movable member (580) that abuts;
A spring (80) for urging the movable member toward the injection hole,
When power is supplied, a magnetic force is generated, and a coil (70) for attracting the movable core to the fixed core side;
A pull-up unit that comes into contact with the needle when power is supplied to the coil and pulls up the needle in the valve opening direction.
With
The needle has a third surface which is a surface formed on the injection hole side so as to come into contact with the lifting portion when power is supplied to the coil,
In a state where the first contact portion and the second surface are in contact with each other, a gap is formed between the lifting portion and the third surface,
The outer diameter of the movable member is larger than the inner diameter of the through hole,
A fuel injection valve, wherein an end surface of the movable member opposite to the injection hole faces an end surface of the fixed core on the injection hole side.

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