JP5979010B2 - Direct injection engine fuel injection system - Google Patents

Description

  The present invention relates to a fuel injection device for a direct injection engine that directly injects fuel into a cylinder of the engine.

  An injector provided in a direct injection engine generally has a hollow injector body having an injection hole at one end and is movable in the longitudinal direction to the injector body so that high-pressure fuel can be injected against the pressure in the cylinder. The needle valve is closed by sitting on a seating surface that is housed and provided with the nozzle hole, and the nozzle valve opens the nozzle hole by being separated (lifted) from the seat surface, and the needle valve is lifted from the seat surface. A solenoid device.

  Patent Document 1 discloses a double solenoid injector including a small lift solenoid device for lifting the needle valve by a relatively small amount and a large lift solenoid device for lifting a relatively large amount. ing. According to this, the fuel injection amount can be reduced by operating the small lift solenoid device at low load to reduce the lift amount of the needle valve, and the large lift solenoid device is operated at high load. By increasing the lift amount of the needle valve, the fuel injection amount can be increased.

  Patent Document 2 discloses a flying armature type injector that can apply a large force to the needle valve when the valve is opened. In this injector, the movable iron core of the solenoid device is not fixed to the needle valve, and is provided to be movable relative to the needle valve in the longitudinal direction of the needle valve. The movable iron core abuts against the stopper portion without being attracted to the solenoid coil when the valve is closed, that is, when the solenoid device is not operated. When the movable iron core is opened, that is, when the solenoid device is activated, the movable iron core is attracted by the solenoid coil, starts moving toward the solenoid coil, stores kinetic energy during the movement, and is provided in the needle valve in that state. The needle valve collides with the protruding portion, and the needle valve is separated from the seat surface by the impact force.

JP 2005-508477 A (paragraphs 0014 to 0016) US Patent Publication 2011/0315795 (paragraphs 0026-0027)

  In a double solenoid injector, it is proposed to apply a flying armature system in order to reliably lift the needle valve even under high fuel pressure conditions. In that case, one of the things to be achieved is that the needle valve lifts responsively. That is, because of the high fuel pressure, the fuel injection amount per unit time at the time of valve opening increases, and the accuracy of the valve opening time is important for accurate control of the fuel injection amount. This is because it is necessary to lift with good responsiveness.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a flying armature type double solenoid injector in which a needle valve can lift with high responsiveness.

In order to solve the above-described problems, the present invention includes a hollow injector body having a nozzle hole at one end, and a seat that is accommodated in the injector body so as to be movable in a longitudinal direction and is provided with the nozzle hole. A needle valve that closes the nozzle hole and opens the nozzle hole by moving away from the seating surface, a first solenoid device for separating the needle valve from the seating surface by a first amount, and the needle valve on the seating surface And a second solenoid device for separating the second solenoid device by a second amount larger than the first amount, wherein the first solenoid device and the second solenoid device are respectively The first movable iron core and the second movable iron core, which are movable relative to the needle valve in the longitudinal direction of the needle valve, and the first movable iron core and the second movable iron core are sucked. A first solenoid coil and a second solenoid coil, and a first stopper part and a second stopper part that are in contact with the first movable iron core and the second movable iron core when the first solenoid device and the second solenoid device are not operated. The first movable iron core and the second movable iron core, which are provided in the needle valve and move toward the first solenoid coil and the second solenoid coil when the first solenoid device and the second solenoid device are operated, are moving. Both the first solenoid device and the second solenoid device are operated when the valve is opened to separate the needle valve from the seat surface by the second amount. The timing at which the first movable iron core collides with the first protrusion is different from the timing at which the second movable iron core collides with the second protrusion. Solenoid device and the second solenoid device Ru fuel injector der direct-injection engine, wherein Rukoto actuated.

  According to the present invention, there is provided a flying solenoid armature type double solenoid injector comprising a first solenoid device for a small lift and a second solenoid device for a large lift, wherein the movable iron core collides with the protruding portion of the needle valve when the valve is opened. Provided.

  In addition, not only the second solenoid device but also the first solenoid device, which is normally inoperative, is operated when the valve is opened (at the time of a large lift) in which the needle valve is separated from the seat surface by a second amount. Therefore, the first movable iron core of the first solenoid device is attracted to the first solenoid coil and released from the first stopper portion. Therefore, the first movable iron core is not dragged by the needle valve via the first stopper portion. Therefore, an unnecessary load is not applied to the needle valve during a large lift, and the needle valve is lifted with good responsiveness.

  As described above, according to the present invention, there is provided a flying armature type double solenoid injector in which the needle valve can be lifted with high responsiveness.

In addition , the first solenoid device and the second solenoid device are operated so that the timing at which the first movable iron core collides with the first projecting portion and the timing at which the second movable iron core collides with the second projecting portion are different from each other. Ru is.

  According to this configuration, since the impact force applied to the needle valve by the first movable iron core and the impact force applied to the needle valve by the second movable iron core act on the needle valve with a time difference, the lift speed of the needle valve is improved as a whole. The needle valve is lifted more responsively.

In the present invention, preferably, the timing for operating the second solenoid device and timing for operating said first solenoid device that differ from each other.

  According to this configuration, since the operation timing of the first solenoid device and the operation timing of the second solenoid device are different from each other, the timing at which the first movable iron core collides with the first protrusion and the second movable iron core are the second. The timing of collision with the protrusions is surely different from each other.

In the present invention, preferably, the idle travel distance from the position where the first movable iron core is in contact with the first stopper portion to the collision with the first projecting portion and the second movable iron core are the second stopper portion. and an empty run distance from the position abutting until impinging on the second protrusion is that different from each other.

  According to this configuration, since the idle running distance of the first movable iron core and the idle running distance of the second movable iron core are different from each other, the timing at which the first movable iron core collides with the first projecting portion and the second movable iron core are The timing of collision with the second projecting portion is surely different from each other.

In the present invention, preferably, a suction force which the first suction force and the second solenoid coil solenoid coil to attract the first movable core to attract the second movable iron core that different from each other.

  According to this configuration, since the attractive force of the first solenoid coil and the attractive force of the second solenoid coil are different from each other, the timing at which the first movable iron core collides with the first protrusion and the second movable iron core are the second. The timing of collision with the protrusions is surely different from each other.

  ADVANTAGE OF THE INVENTION According to this invention, the double solenoid injector of a flying armature system with which a needle valve can lift with sufficient responsiveness is provided.

It is sectional drawing which shows the whole structure of the fuel-injection apparatus of the direct injection engine which concerns on embodiment of this invention. It is the elements on larger scale of the solenoid apparatus for small lifts of the said fuel injection apparatus. It is the elements on larger scale of the solenoid apparatus for large lifts of the said fuel injection apparatus. It is a schematic diagram which shows the principal part structure of the said fuel injection apparatus. It is a schematic diagram at the time of a small lift of the fuel injection device. It is a schematic diagram at the time of a large lift of the fuel injection device. It is a schematic diagram at the time of the transition at the time of the big lift of the said fuel injection apparatus.

(1) Whole structure First, with reference to FIGS. 1-6, the whole structure of the fuel-injection apparatus of the direct injection engine which concerns on this embodiment is demonstrated.

  FIG. 1 is a cross-sectional view showing the overall configuration of a fuel injection device (injector) 10 for a direct injection engine according to the present embodiment, FIG. 2 is a partially enlarged view of a small lift solenoid device 20 of the injector 10, and FIG. FIG. 2 is a partially enlarged view of a large lift solenoid device 30 of the injector 10. 4 is a schematic diagram showing the configuration of the main part of the injector 10, FIG. 5 is a schematic diagram when the injector 10 is small lifted, and FIG. 6 is a schematic diagram when the injector 10 is large lifted.

  The injector 10 according to the present embodiment is provided in a direct injection engine, and is configured to inject fuel at a high pressure (for example, about 40 to 120 MPa) against the pressure in the cylinder. The injector 10 includes a cylindrical shell inner 11 and a nozzle 12 coupled to one end side (the lower end side in the drawing) of the shell inner 11. A nozzle hole 13 is formed at one end of the nozzle 12 (lower end in the drawing). The shell inner 11 and the nozzle 12 constitute a hollow injector body 15 having a nozzle 13 at one end.

  A needle valve 16 is accommodated in the injector body 15 so as to be movable in the longitudinal direction (vertical direction in the drawing). The needle valve 16 moves to one end side (lower end side in the drawing) of the injector body 15 and is seated on the seat surface 15a on which the nozzle hole 13 is formed, thereby closing the nozzle hole 13 and the other end side of the injector body 15 ( The nozzle 13 is opened by moving to the upper end side in the drawing and separating (lifting) from the seating surface 15a.

  A spring adjustment pipe 41 is provided on the inner surface of the solenoid coil 22 of the small lift solenoid device 20 to be described next, and the needle valve 16 is connected to one end of the injector body 15 between the spring adjustment pipe 41 and the needle valve 16. A coil spring 42 for closing the valve that is always biased to the side is provided.

  The injector body 15 accommodates a small lift solenoid device 20 and a large lift solenoid device 30 for lifting the needle valve 16 from the seat surface 15a. The small lift solenoid device 20 corresponds to the first solenoid device of the present invention, and lifts the needle valve 16 from the seat surface 15a by a small lift amount (first amount). The large lift solenoid device 30 corresponds to the second solenoid device of the present invention, and lifts the needle valve 16 from the seat surface 15a by a large lift amount (second amount) larger than the small lift amount. That is, the injector 10 according to this embodiment is a double solenoid injector provided with two solenoid devices.

  The small lift solenoid device 20 and the large lift solenoid device 30 are arranged from the one end side of the injector body 15 in the order of the large lift solenoid device 30 and the small lift solenoid device 20.

  In the injector 10 according to the present embodiment, a flying armature system is applied to reliably lift the needle valve 16 even under a high fuel pressure condition. That is, the injector 10 according to the present embodiment is a double solenoid injector to which a flying armature system is applied.

  Specifically, the small lift solenoid device 20 includes a first movable iron core 21 and a first solenoid coil 22. The first movable iron core 21 is movable relative to the needle valve 16 in the longitudinal direction of the needle valve 16. When the first solenoid coil 22 is energized, the first movable iron core 21 is attracted by a magnetic force. The needle valve 16 is provided with a stopper tube 23 as a first stopper portion. The stopper tube 23 is provided separately from the needle valve 16 and is press-fitted into the outer surface of the needle valve 16. The needle valve 16 is provided with a protruding tube 24 as a first protruding portion. The protruding tube 24 is also provided separately from the needle valve 16 and is press-fitted into the outer surface of the needle valve 16. The stopper tube 23 and the protruding tube 24 protrude outward from the outer surface of the needle valve 16.

  When the small lift solenoid device 20 is not operated, that is, when the first solenoid coil 22 is not energized, one end (the lower end in the drawing) of the needle valve 16 is pressed against the seat surface 15a by the biasing force of the coil spring 42. The nozzle 13 is closed. When the valve is closed, the first movable iron core 21 is urged by appropriate urging means (not shown) and is in contact with the stopper tube 23 (see FIG. 2).

  When the small lift solenoid device 20 is operated (at the time of small lift), that is, when the first solenoid coil 22 is energized, the first movable iron core 21 is attracted by the first solenoid coil 22 and directed toward the first solenoid coil 22. Start moving. The first movable iron core 21 accumulates kinetic energy during the movement, collides with the protruding tube 24 in that state, and lifts the needle valve 16 from the seating surface 15a by the impact force. The first movable iron core 21 then contacts the first solenoid coil 22 to maintain the needle valve 16 in a small lift open state (see FIG. 5).

  Here, when the small lift is opened, the moving distance S1 from the position where the first movable iron core 21 abuts against the stopper pipe 23 to the collision with the projecting pipe 24 is the empty space in which the first movable iron core 21 stores kinetic energy. It is mileage. Thereafter, the moving distance L1 from when the first movable iron core 21 collides with the protruding tube 24 until it contacts the first solenoid coil 22 is a separation distance from the seat surface 15a of the needle valve 16, that is, a small lift amount. Yes (see FIGS. 2 and 4).

  As shown in FIG. 4, the idle running distance S1 of the first movable iron core 21 is a value obtained by subtracting the thickness of the first movable iron core 21 from the distance Lx1 between the stopper pipe 23 and the protruding pipe 24 in the valve-closed state. The distance at which kinetic energy is stored before the first movable iron core 21 collides with the protruding tube 24. Since the idling distance S1 is an important parameter for a flying armature injector, the distance Lx1 between the stopper tube 23 and the protruding tube 24 needs to be adjusted with high accuracy. Hereinafter, the distance Lx1 is referred to as an adjusted distance Lx1 of the small lift solenoid device 20.

  On the other hand, the large lift solenoid device 30 includes a second movable iron core 31 and a second solenoid coil 32. The second movable iron core 31 is movable relative to the needle valve 16 in the longitudinal direction of the needle valve 16. When energized, the second solenoid coil 32 attracts the second movable iron core 31 with a magnetic force. A stopper member 33 as a second stopper portion is provided on one end side of the injector body 15 (specifically, the shell inner 11). The stopper member 33 is provided separately from the injector body 15 and is press-fitted into the inner surface of the injector body 15. The stopper member 33 protrudes inward from the inner surface of the injector body 15. The needle valve 16 is provided with a protruding step 34 as a second protruding portion. The protruding step 34 is formed integrally with the needle valve 16 and protrudes outward from the outer surface on one end side of the needle valve 16. An engagement step portion 31a that can engage with the protruding step portion 34 is formed in the second movable iron core 31 (see FIG. 3).

  When the large lift solenoid device 30 is not operated, that is, when the second solenoid coil 32 is not energized, one end (the lower end in the drawing) of the needle valve 16 is pressed against the seat surface 15a by the biasing force of the coil spring 42. The nozzle 13 is closed. When the valve is closed, the second movable iron core 31 is urged by appropriate urging means (not shown) and is in contact with the stopper member 33 (see FIG. 3).

  During operation of the large lift solenoid device 30 (during large lift), that is, when the second solenoid coil 32 is energized, the second movable iron core 31 is attracted by the second solenoid coil 32 and directed toward the second solenoid coil 32. Start moving. And the 2nd movable iron core 31 accumulate | stores kinetic energy during the movement, it collides with the protrusion step part 34 by the engagement step part 31a in the state, and lifts the needle valve 16 from the seat surface 15a with the impact force. And the 2nd movable iron core 31 maintains the needle valve 16 in the valve opening state of a large lift by contact | abutting on the 2nd solenoid coil 32 after that (refer FIG. 6).

  Here, when the large lift valve is opened, the moving distance S2 from the position where the second movable core 31 abuts against the stopper member 33 until the projecting step 34 collides with the engaging step 31a is the second movable core. 31 is the free running distance for storing kinetic energy. After that, the moving distance L2 from when the second movable iron core 31 collides with the projecting step portion 34 until it comes into contact with the second solenoid coil 32 is the separation distance from the seat surface 15a of the needle valve 16, that is, a large lift amount. (See FIGS. 3 and 4).

  As shown in FIG. 4, the idle running distance S2 of the second movable iron core 31 is determined from the distance Lx2 between the stopper member 33 and the protruding step 34 in the valve-closed state. This is a value obtained by subtracting the thickness up to the stepped portion 31a, and is a distance for storing kinetic energy before the second movable iron core 31 collides with the protruding stepped portion 34. Since the idling distance S2 is an important parameter for a flying armature type injector, it is necessary to adjust the distance Lx2 between the stopper member 33 and the protruding step 34 with high accuracy. Hereinafter, the distance Lx2 is referred to as an adjusted distance Lx2 of the large lift solenoid device 30.

  In the present embodiment, the needle valve 16 is mounted on the injector body 15, and the actual injection characteristics of the injector 10 when the small lift solenoid device 20 or the large lift solenoid device 30 is operated are inspected. Accordingly, the adjusted distance Lx1 of the small lift solenoid device 20 or the adjusted distance Lx2 of the large lift solenoid device 30 is adjusted.

  In addition to the above configuration, in the present embodiment, not only the large lift solenoid device 30 but also the non-actuation is originally not activated when the needle valve 16 is lifted from the seating surface 15a by a large lift amount L2 (at the time of large lift). A small lift solenoid device 20 is also activated. That is, as shown in FIG. 6, both the small lift solenoid device 20 and the large lift solenoid device 30 are operated during a large lift.

  In the present embodiment, when both the small lift solenoid device 20 and the large lift solenoid device 30 are operated during a large lift, the timing at which the first movable iron core 21 collides with the protruding tube 24 and the second movable iron core. It operates so that the timing which 31 collides with the protrusion step part 34 mutually differs.

  As shown in FIG. 1, double pipes 51 and 52 and middle bodies 53 and 54 are press-fitted into the outer surface of the shell inner 11. The injector 10 includes a nozzle 12, a shell outer 55 that covers the shell inner 11, a top body 56 that is coupled to the other end side (the upper end side in the drawing) of the shell inner 11, and a top body 56 that is engaged with the shell outer 55. The external appearance is formed by the retaining nut 57 to be screwed together.

  High-pressure (for example, about 40 to 120 MPa) fuel pumped from a high-pressure fuel pump (not shown) includes an inflow passage 61 formed in the top body 56, an internal space of the first solenoid coil 22, and an interior of the needle valve 16. The fuel passage 62 is formed in the nozzle valve 12, the communication passage 63 is formed on one end of the needle valve 16, and the inner space of the nozzle 12. In FIG. 1, reference numeral 71 denotes an annular member that is press-fitted into the inner surface of the nozzle 12 in order to bring out the center of the needle valve 16.

(2) Characteristic Configuration Next, a characteristic configuration of the injector 10 according to the present embodiment will be described.

[A] Stopper Tube 23 of Small Lift Solenoid Device 20 In this embodiment, the stopper valve 23 of the small lift solenoid device 20 is provided on the needle valve 16. This is a configuration adopted from the viewpoint of dimensional accuracy.

  As described above, the adjusted distance Lx1 (the distance between the stopper tube 23 and the protruding tube 24) of the small lift solenoid device 20 is a parameter that determines the idle travel distance S1 of the first movable iron core 21. It is necessary to adjust accurately. The protruding tube 24 is unavoidably provided on the needle valve 16 because of its function. Therefore, when the stopper tube 23 is provided on the needle valve 16, both the stopper tube 23 and the protruding tube 24 are provided on the single needle valve 16. Then, even if the needle valve 16 is not accommodated in the injector body 15, before the needle valve 16 is accommodated in the injector body 15, the position of the stopper pipe 23 and the position of the projecting pipe 24 are adjusted, whereby the small lift solenoid The adjusted distance Lx1 of the device 20 can be adjusted. Therefore, the adjustment distance Lx1 can be adjusted with high accuracy.

  On the other hand, when the stopper tube 23 is provided on the injector body 15, the stopper tube 23 and the protruding tube 24 are provided separately on the injector body 15 and the needle valve 16. Then, unless the needle valve 16 is accommodated in the injector body 15, the adjusted distance Lx1 of the small lift solenoid device 20 cannot be adjusted. Moreover, since the position of the stopper tube 23 cannot be adjusted after the stopper tube 23 is assembled to the injector body 15, the degree of freedom of adjustment of the adjusted distance Lx1 of the small lift solenoid device 20 is reduced. Lx1 cannot be adjusted with high accuracy.

  As described above, in this embodiment, the stopper valve 23 of the small lift solenoid device 20 is provided in the needle valve 16 from the viewpoint of dimensional accuracy of the injector 10.

[B] Operation of Solenoid Devices 20 and 30 during Large Lift In this embodiment, both the small lift solenoid device 20 and the large lift solenoid device 30 are operated during a large lift. This is a configuration adopted from the viewpoint of valve opening response.

  If the stopper valve 23 of the small lift solenoid device 20 is provided on the needle valve 16 from the viewpoint of the dimensional accuracy of the injector 10 as in [A], the following problems occur during a large lift. That is, at the time of a large lift, the second movable iron core 31 collides with the protruding step portion 34 and then moves by the large lift amount L2, whereby the needle valve 16 is lifted by the large lift amount L2. Therefore, if the stopper pipe 23 of the small lift solenoid device 20 is provided in the needle valve 16, the stopper pipe 23 also moves together with the needle valve 16 by the large lift amount L2, so the small lift solenoid device 20 must be operated. For example, the first movable iron core 21 of the small lift solenoid device 20 in contact with the stopper pipe 23 is dragged and moved by the needle valve 16. This increases the load on the second movable iron core 31 and decreases the valve opening response of the injector 10.

  Therefore, as shown in FIG. 6, in addition to the large lift solenoid device 30, the small lift solenoid device 20, which is originally inoperative, is operated even during a large lift. As a result, the first movable iron core 21 is attracted by the first solenoid coil 22 and released from the stopper tube 23, so that the first movable iron core 21 is prevented from being dragged and moved by the needle valve 16. Therefore, an unnecessary load is not applied to the second movable iron core 31 during a large lift, and the needle valve 16 lifts with high responsiveness even under high fuel pressure conditions.

  As described above, in the present embodiment, from the viewpoint of valve opening response of the injector 10, both the small lift solenoid device 20 and the large lift solenoid device 30 are operated during a large lift.

[C] Collision Timing of Movable Iron Cores 21 and 31 at the Time of Large Lift In this embodiment, the timing at which the first movable iron core 21 collides with the protruding tube 24 at the time of large lift and the second movable iron core 31 collide with the protruding step 34. The timing to do is different from each other. This is a configuration adopted from the viewpoint of improving the lift speed.

  As described in [B] above, when both the small lift solenoid device 20 and the large lift solenoid device 30 are operated during a large lift from the viewpoint of valve opening response of the injector 10, When the first movable iron core 21 and the second movable iron core 31 of the large lift solenoid device 30 are displaced in time and collide with the projecting tube 24 and the projecting step portion 34, the first movable iron core 21 has an impact on the needle valve 16. The force and the impact force applied to the needle valve 16 by the second movable iron core 31 act on the needle valve 16 with a time difference. Therefore, the needle valve 16 is lifted by the impact force of the one movable iron core 21 or 31, and the other movable iron core 31 or 21 collides with the needle valve 16 at the timing when the lift speed is decelerated. The needle valve 16 is accelerated more efficiently than the time 21 and the second movable iron core 31 collide with the needle valve 16 at the same time, and the lift speed of the needle valve 16 is improved as a whole. As a result, the needle valve 16 is lifted with higher responsiveness.

  As described above, in the present embodiment, the collision timing of the first movable iron core 21 and the collision timing of the second movable iron core 31 are different from each other during a large lift from the viewpoint of improving the lift speed.

  Specifically, in the present embodiment, as shown in FIG. 4, the first traveling iron core 21 and the second movable iron core 31 have different running distances S <b> 1 and S <b> 2 by different distances. The timing at which the movable iron core 21 collides with the protruding tube 24 and the timing at which the second movable iron core 31 collides with the protruding step portion 34 are different from each other.

  In particular, in the present embodiment, as is apparent from FIG. 4, the idle running distance S <b> 1 of the first movable iron core 21 is made larger than the idle running distance S <b> 2 of the second movable iron core 31. Therefore, for example, if the operation timings of both solenoid devices 20 and 30 are the same, and the attractive forces (the number of turns of the coil, the energization current, etc.) of both solenoid coils 22 and 32 are also the same, The second movable iron core 31 of the short large lift solenoid device 30 first collides with the protruding step portion 34, and the first movable iron core 21 of the small lift solenoid device 20 with a long idle travel distance collides with the protruding tube 24 later. . As a result, a time difference is created between the timing at which the second movable iron core 31 collides with the protruding step portion 34 and the timing at which the first movable iron core 21 collides with the protruding tube 24, and the lift speed of the needle valve 16 is higher than that at the same time. Is improved, and the valve opening response of the injector 10 is further improved.

  However, when the second movable iron core 31 collides with the protruding step 34 first, the needle valve 16 is largely lifted, and the protruding tube 24 moves beyond the first solenoid coil 22 to the valve opening side. The first movable iron core 21 can no longer collide with the protruding tube 24, and as a result, the valve opening state of the large lift can be achieved without the first movable iron core 21 being able to give an impact force to the needle valve 16 even once. There is sex.

  In order to avoid this problem, in this embodiment, the small lift solenoid device 20 having the long free running distance S1 of the movable iron core 21 is operated first, and the large lift solenoid device having the short free running distance S2 of the movable iron core 31 is operated. 30 is activated later. Alternatively, the attractive force of the first solenoid coil 22 may be larger than the attractive force of the second solenoid coil 32. As a result, as shown in FIG. 7, the first movable iron core 21 of the small lift solenoid device 20 having a long idle travel distance first collides with the protruding tube 24, and the first lift iron device 30 of the large lift solenoid device 30 having a short idle travel distance is obtained. 2 Since the movable iron core 31 collides with the projecting step portion 34 later, when the first movable iron core 21 collides with the projecting tube 24 first, the projecting step portion 34 does not move excessively to the valve opening side, After the collision of the first movable iron core 21, the second movable iron core 31 reliably collides with the protruding step 34.

  Note that when the idle running distance S1 of the first movable iron core 21 and the idle running distance S2 of the second movable iron core 31 are different from each other, the idle running distance S2 of the second movable iron core 31 is opposite to the above. May be larger than the free running distance S1 of the first movable iron core 21.

(3) Operation, etc. An injector 10 of a direct injection engine according to the present embodiment is accommodated in a hollow injector body 15 having an injection hole 13 at one end, and is movable in the longitudinal direction in the injector body 15. A needle valve 16 that closes the nozzle hole 13 by sitting on the seat surface 15a and opens the nozzle hole 13 by separating from the seat surface 15a, and lifts the needle valve 16 from the seat surface 15a by a small lift amount. A small lift solenoid device 20 and a large lift solenoid device 30 for lifting the needle valve 16 from the seat surface 15a by a large lift amount, and has the following characteristic configuration. doing.

  The small lift solenoid device 20 and the large lift solenoid device 30 respectively include a first movable iron core 21 and a second movable iron core 31 that can move relative to the needle valve 16 in the longitudinal direction of the needle valve 16, and The first solenoid coil 22 and the second solenoid coil 32 for attracting the first movable iron core 21 and the second movable iron core 31, and the first and second lift solenoid devices 20 and 30 are not operated. A stopper pipe 23 and a stopper member 33 with which the movable iron core 21 and the second movable iron core 31 abut, and the needle valve 16 are provided. The first solenoid is operated when the small lift solenoid device 20 and the large lift solenoid device 30 are operated. The first movable iron core 21 and the second movable core that move toward the coil 22 and the second solenoid coil 32. Core 31 has a protruding tube 24 and the projecting step portion 34 collides during the movement. Then, both the small lift solenoid device 20 and the large lift solenoid device 30 are operated when the needle valve 16 is opened from the seat surface 15a by a large lift amount.

  According to this configuration, the flying armature includes the small lift solenoid device 20 and the large lift solenoid device 30, and the movable iron cores 21 and 31 collide with the protruding pipe 24 and the protruding step portion 34 of the needle valve 16 when the valve is opened. A double solenoid injector 10 of the type is provided.

  In addition, when opening the needle valve 16 from the seat surface 15a by a large lift amount (at the time of large lift), not only the large lift solenoid device 30 but also a small lift solenoid device that may be essentially inoperative. Therefore, the first movable iron core 21 of the small lift solenoid device 20 is attracted to the first solenoid coil 22 and released from the stopper tube 23. Therefore, the first movable iron core 21 is not dragged to the needle valve 16 via the stopper tube 23. Therefore, an unnecessary load is not applied to the needle valve 16 during a large lift, and the needle valve 16 is lifted with good responsiveness.

  As described above, according to this embodiment, the flying armature type double solenoid injector 10 in which the needle valve 16 can be lifted with high responsiveness is provided.

  In the present embodiment, the small lift solenoid device 20 is configured such that the timing at which the first movable iron core 21 collides with the protruding tube 24 and the timing at which the second movable iron core 31 collides with the protruding step 34 are different from each other. And the large lift solenoid device 30 is activated.

  According to this configuration, the impact force that the first movable iron core 21 applies to the needle valve 16 and the impact force that the second movable iron core 31 applies to the needle valve 16 act on the needle valve 16 with a time difference. The speed is improved as a whole, and the needle valve 16 is lifted more responsively.

  Further, in the present embodiment, the idle travel distance S1 from the position where the first movable iron core 21 abuts against the stopper tube 23 to the collision with the protruding tube 24 and the second movable iron core 31 are the stopper member. The idle running distance S2 from the position in contact with 33 to the collision with the protruding step 34 is different from each other.

  According to this configuration, since the idle running distance S1 of the first movable iron core 21 and the idle running distance S2 of the second movable iron core 31 are different from each other, the timing at which the first movable iron core 21 collides with the protruding tube 24 and the first The timing at which the two movable iron cores 31 collide with the protruding step portion 34 is surely different from each other.

  Instead of making the idle travel distance S1 of the first movable iron core 21 and the idle run distance S2 of the second movable iron core 31 different from each other, the timing for operating the small lift solenoid device 20 and the large lift solenoid device are different. The timing at which 30 is operated may be different from each other, and the first solenoid coil 22 attracts the first movable iron core 21 (the number of turns of the coil, the energization current, etc.) and the second solenoid coil 32 The suction force for sucking the second movable iron core 31 may be different from each other.

  Also with these configurations, the operation timing of the small lift solenoid device 20 and the operation timing of the large lift solenoid device 30 are different from each other, and the attraction force of the first solenoid coil 22 and the second solenoid coil 32 Since the suction force is different from each other, the timing at which the first movable iron core 21 collides with the protruding tube 24 and the timing at which the second movable iron core 31 collides with the protruding step portion 34 are surely different from each other.

  Further, a stopper member 33 of the large lift solenoid device 30 may be provided on the needle valve 16 depending on the situation. In that case, since both the stopper member 33 and the protruding step portion 34 of the large lift solenoid device 30 are provided in the single needle valve 16, the protrusion of the stopper member 33 and the protrusion before the needle valve 16 is accommodated in the injector body 15. The distance Lx2 between the step portion 34 can be adjusted. Therefore, the distance adjustment can be performed with high accuracy.

  In the above-described embodiment, the second projecting portion of the large lift solenoid device 30 is the projecting step portion 34 formed integrally with the needle valve 16, but it may be a pipe member press-fitted into the outer surface of the needle valve 16.

  Further, the stopper tube 23 and the protruding tube 24 of the small lift solenoid device 20 and the stopper member 33 of the large lift solenoid device 30 may be fixed by welding or the like after press-fitting.

10 Injector (fuel injection device)
11 Shell Inner 12 Nozzle 13 Injection Port 15 Injector Body 15a Seat 16 Needle Valve 20 Small Lift Solenoid Device (First Solenoid Device)
21 Movable iron core of small lift solenoid device (first movable iron core)
22 Solenoid coil for the small lift solenoid device (first solenoid coil)
23 Stopper pipe (first stopper part) of solenoid device for small lift
24 Projection tube (first projection) of solenoid device for small lift
30 Solenoid device for large lift (second solenoid device)
31 Movable iron core (second movable iron core) of solenoid device for large lift
31a Engagement step 32 Solenoid coil of second lift solenoid device (second solenoid coil)
33 Stopper member (second stopper part) of solenoid device for large lift
34 Projection step (second projection) of solenoid device for large lift
42 Coil spring for valve closing L1 Small lift amount (first amount) of solenoid device for small lift
L2 Large lift amount of solenoid device for large lift (second amount)
Lx1 Adjusted distance of small lift solenoid device Lx2 Adjusted distance of large lift solenoid device S1 Free running distance of movable iron core of small lift solenoid device S2 Free running distance of movable iron core of large lift solenoid device

Claims (4)

A hollow injector body having a nozzle at one end;
A needle valve which is accommodated in the injector body so as to be movable in the longitudinal direction, closes the nozzle hole by sitting on a seat surface provided with the nozzle hole, and opens the nozzle hole by separating from the seat surface;
A first solenoid device for separating the needle valve from the seating surface by a first amount;
A fuel injection device for a direct injection engine comprising: a second solenoid device for separating the needle valve from a seat surface by a second amount greater than the first amount;
The first solenoid device and the second solenoid device are respectively
A first movable iron core and a second movable iron core that are movable relative to the needle valve in the longitudinal direction of the needle valve;
A first solenoid coil and a second solenoid coil for sucking the first movable iron core and the second movable iron core;
A first stopper portion and a second stopper portion with which the first movable iron core and the second movable iron core come into contact when the first solenoid device and the second solenoid device are not operated;
The first movable iron core and the second movable iron core, which are provided in the needle valve and move toward the first solenoid coil and the second solenoid coil when the first solenoid device and the second solenoid device are operated, are being moved. Having a first protrusion and a second protrusion that collide,
Both the first solenoid device and the second solenoid device are actuated when the needle valve is opened to separate the needle valve from the seat surface by the second amount ;
The first movable iron core Ru is actuated the timing impinging on the first protrusion second movable iron core wherein such that the timing at which strikes the second projecting portions differ from each other the first solenoid device and the second solenoid device A fuel injection device for a direct injection engine. The fuel injection device for a direct injection engine according to claim 1 ,
The fuel injection device for a direct injection engine, wherein the timing for operating the first solenoid device and the timing for operating the second solenoid device are different from each other. The fuel injection device for a direct injection engine according to claim 1 or 2 ,
From the position where the first movable iron core is in contact with the first stopper portion and the position where the second movable iron core is in contact with the second stopper portion from the position where the first movable iron core collides with the first protrusion. The fuel injection device for a direct injection engine, wherein an idle running distance until the second projecting portion collides with each other is different from each other. In the fuel-injection apparatus of the direct-injection engine of any one of Claim 1 to 3 ,
The direct-injection engine fuel wherein the first solenoid coil attracts the first movable iron core and the second solenoid coil attracts the second movable iron core are different from each other. Injection device.

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