JP5979009B2 - 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 this case, one of the things to be achieved is that the movable iron core of the small lift solenoid device does not interfere with the large lift of the needle valve when the large lift solenoid device is activated (during the large lift).

  Therefore, an object of the present invention is to provide a flying armature type double solenoid injector in which the movable iron core of the small lift solenoid device does not interfere with the large lift of the needle valve during a large lift.

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. A first projecting portion and a second projecting portion that collide with each other, wherein the first stopper portion is provided on the needle valve, and the first movable iron core is disposed on the first stopper portion when the first solenoid device is operated. The idle running distance from the abutting position to the collision with the first protrusion is S1, and after the first movable iron core collides with the first protrusion, the first solenoid The lift amount until contact with the second coil is L1, and the lift amount until the second movable iron core comes into contact with the second solenoid coil after the second movable iron core collides with the second projecting portion when the second solenoid device is operated is L2. In this case, the fuel injection device of the direct injection engine is characterized in that S1 + L1 ≧ L2 is set (claim 1).

  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, since the sum of the idle travel distance S1 of the first movable iron core and the lift amount L1 of the first movable iron core is set to be equal to or greater than the lift amount L2 of the second movable iron core (S1 + L1 ≧ L2), the second solenoid Even when the needle valve is lifted by L2 during operation of the device (during a large lift) and the distance between the first stopper portion and the first solenoid coil is reduced by L2, the first movable iron core remains in the first stopper portion. And the first solenoid coil. Therefore, the needle valve is lifted by L2 without any trouble.

  As described above, according to the present invention, there is provided a flying armature type double solenoid injector in which the movable iron core of the small lift solenoid device does not interfere with the large lift of the needle valve during a large lift.

  By the way, the value obtained by subtracting the thickness of the movable iron core from the distance between the stopper and the protrusion when the valve is closed is the free running distance that stores kinetic energy until the movable iron collides with the protrusion. This is an important parameter for this injector. Therefore, it is necessary to accurately adjust the distance between the stopper portion and the protruding portion.

Therefore, in the present invention, preferably, prior Symbol first stopper portion and the first projecting portion, the needle valve and provided in a separate body, it is press-fitted into the outer surface of the needle valve (claim 2).

  According to this configuration, since both the first stopper portion and the first projecting portion of the first solenoid device are provided in the needle valve, the first stopper portion and the first projecting portion are disposed before the needle valve is accommodated in the injector body. The distance between can be adjusted. Therefore, the distance adjustment can be performed with high accuracy. In addition, since the first stopper portion and the first projecting portion are press-fitted, the distance between the first stopper portion and the first projecting portion can be continuously adjusted, and the distance adjustment can be performed more accurately. It can be carried out.

  In the present invention, preferably, the first solenoid device and the second solenoid device are arranged in order of the second solenoid device and the first solenoid device from the one end side, and the second stopper portion is separated from the injector body. And is provided on the one end side of the injector body by being press-fitted into the inner surface of the injector body (Claim 3).

  According to this configuration, since the second stopper portion of the second solenoid device is provided on the injector body, in order to adjust the distance between the second stopper portion of the second solenoid device and the second protruding portion, the needle It is necessary to accommodate the valve in the injector body. However, since the second stopper portion is provided on the one end side of the injector body, if the one end side of the injector body is opened, the needle valve is accommodated in the injector body with the second stopper portion and the second projecting portion. The distance between can be adjusted. In addition, since the second stopper portion is press-fitted, the position of the second stopper portion can be continuously adjusted, and the distance between the second stopper portion and the second protruding portion can be adjusted accurately. it can.

  According to the present invention, a flying armature type double solenoid injector is provided in which the movable iron core of the small lift solenoid device does not interfere with the large lift of the needle valve during a large lift.

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 explanatory drawing of the malfunction which generate | occur | produces at the time of the small lift of the said fuel injection apparatus. It is a schematic diagram of the fuel-injection apparatus of the structure which a malfunction generate | occur | produces at the time of a big lift. It is explanatory drawing of the malfunction which generate | occur | produces 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 this embodiment, the sum of the idle travel distance S1 of the first movable iron core 21 of the small lift solenoid device 20 and the small lift amount L1 of the small lift solenoid device 20 is the large lift solenoid device 30. More than the large lift amount L2, that is, S1 + L1 ≧ L2.

  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] Stopper member 33 of solenoid device 30 for large lift In this embodiment, the stopper member 33 of solenoid device 30 for large lift is provided on the injector body 15. This is a configuration adopted from the viewpoint of valve opening response.

  If the stopper member 33 of the large lift solenoid device 30 is provided on the needle valve 16 as shown in FIG. 7 as shown in FIG. Trouble occurs. That is, at the time of a small lift, the first movable iron core 21 collides with the protruding tube 24 and then moves by the small lift amount L1, whereby the needle valve 16 is lifted by the small lift amount L1. Therefore, when the stopper member 33 of the solenoid device 30 for large lift is provided on the needle valve 16, the stopper member 33 also moves together with the needle valve 16 by a small lift amount L1, so that the large lift that is in contact with the stopper member 33. The second movable iron core 31 of the solenoid device 30 is dragged and moved by the needle valve 16. This increases the load on the first movable iron core 21 and reduces the valve opening response of the injector 10.

  On the other hand, as shown in FIG. 5, if the stopper member 33 is provided on the injector body 15, the stopper member 33 does not move together with the needle valve 16 even if the needle valve 16 is lifted during a small lift. Therefore, the second movable iron core 31 of the large lift solenoid device 30 in contact with the stopper member 33 is not dragged and moved by the needle valve 16. Therefore, an unnecessary load is not applied to the first movable iron core 21 during a small lift, and the needle valve 16 lifts with high responsiveness even under high fuel pressure conditions.

  As described above, in this embodiment, the stopper member 33 of the large lift solenoid device 30 is provided in the injector body 15 from the viewpoint of valve opening response of the injector 10.

  Of course, the adjustment distance Lx2 (the distance between the stopper member 33 and the protruding step 34) of the large lift solenoid device 30 is adjusted with the stopper member 33 protruding while the needle valve 16 is housed in the injector body 15. The distance between the step portion 34 is adjusted. However, since the large lift solenoid device 30 is disposed on one end side of the injector body 15 and the stopper member 33 is provided on one end side of the injector body 15 (specifically, the shell inner 11), the needle valve 16 is connected to the injector body 15. Even if the nozzle 12 is removed and the one end side of the injector body 15 is opened without removing it from the nozzle, the adjusted distance Lx2 is obtained by adjusting the position of the stopper member 33 while the needle valve 16 is housed in the injector body 15. Can be adjusted.

  Even if the stopper member 33 is not provided on the injector body 15, if the second movable iron core 31 is released from the stopper member 33 by operating the large lift solenoid device 30, the second movable iron core 31 becomes the needle valve 16. It seems that the stopper member 33 can be provided on the needle valve 16 because it is not dragged. However, when the large lift solenoid device 30 is operated, the lift amount changes to a large lift amount instead of a small lift amount. It is not a solution. That is, at the time of a small lift, only the small lift solenoid device 20 can be operated, and the large lift solenoid device 30 cannot be operated.

[C] Setting of S1 + L1 ≧ L2 In this embodiment, the sum of the idle travel distance S1 of the first movable iron core 21 of the small lift solenoid device 20 and the small lift amount L1 of the small lift solenoid device 20 is for the large lift. The large lift amount L2 of the solenoid device 30 is set. This is from the viewpoint of preventing the first movable iron core 21 of the small lift solenoid device 20 from becoming a hindrance to the large lift of the needle valve 16 during a large lift.

  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. Here, since the lift amount (small lift amount) L1 of the small lift solenoid device 20 is smaller than the lift amount (large lift amount) L2 of the large lift solenoid device 30, as shown in FIG. If the idle running distance S1 of 21 is small, the sum of the idle running distance S1 of the first movable core 21 and the small lift amount L1 may be less than the large lift amount L2, that is, S1 + L1 <L2. Then, as shown in FIG. 9, the first movable iron core 21 of the small lift solenoid device 20 is sandwiched between the stopper tube 23 and the first solenoid coil 22 before the needle valve 16 is lifted by the large lift amount L2. (See symbol (i)). This means that a large lift is prevented for the needle valve 16, and the large lift amount L2 is not realized (see reference numeral (ii)).

  On the other hand, as shown in FIG. 4, the idle travel distance S1 of the first movable iron core 21 is increased, and the sum of the idle travel distance S1 of the first movable iron core 21 and the small lift amount L1 is greater than or equal to the large lift amount L2. That is, when S1 + L1 ≧ L2 is set, as shown in FIG. 6, even if the needle valve 16 is lifted by the large lift amount L2, in other words, the distance between the stopper tube 23 and the first solenoid coil 22 is Even if the distance is reduced by L2, the first movable iron core 21 of the small lift solenoid device 20 is not sandwiched between the stopper tube 23 and the first solenoid coil 22. Therefore, the needle valve 16 performs a large lift without hindrance, and a large lift amount L2 is realized satisfactorily.

  For this reason, in the present embodiment, S1 + L1 ≧ L2 is set from the viewpoint of preventing the first movable iron core 21 of the small lift solenoid device 20 from obstructing the large lift of the needle valve 16 during a large lift. Yes.

(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, when the small lift solenoid device 20 is operated, an idle running distance from the position where the first movable iron core 21 is in contact with the stopper pipe 23 to the collision with the protruding pipe 24 is defined as S1, and the first movable iron The lift amount from when the iron core 21 collides with the protruding tube 24 to contact with the first solenoid coil 22 is L1, and when the large lift solenoid device 30 is operated, the second movable iron core 31 is moved to the protruding step portion. S1 + L1 ≧ L2 is set, where L2 is a lift amount from the collision to the second solenoid coil 32 after the collision with the second solenoid coil 32.

  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, the sum of the free running distance S1 of the first movable iron core 21 and the lift amount L1 of the first movable iron core 21 is set to be equal to or greater than the lift amount L2 of the second movable iron core 31 (S1 + L1 ≧ L2). Even when the large lift solenoid device 30 is operated (at the time of large lift), the needle valve 16 is largely lifted by L2 and the first movable even if the distance between the stopper tube 23 and the first solenoid coil 22 is narrowed by L2. The iron core 21 is not sandwiched between the stopper tube 23 and the first solenoid coil 22. Therefore, the needle valve 16 is lifted by L2 without any trouble.

  As described above, according to the present embodiment, the flying armature type double solenoid injector 10 is provided in which the movable iron core 21 of the small lift solenoid device 20 does not interfere with the large lift of the needle valve 16 during a large lift.

  In this embodiment, the stopper tube 23 is provided on the needle valve 16, and the stopper tube 23 and the protruding tube 24 are provided separately from the needle valve 16, and are provided on the outer surface of the needle valve 16. It is press-fitted.

  According to this configuration, since both the stopper pipe 23 and the protruding pipe 24 of the small lift solenoid device 20 are provided in the needle valve 16, the stopper pipe 23 and the protruding pipe 24 are accommodated before the needle valve 16 is accommodated in the injector body 15. The distance Lx1 between can be adjusted. Therefore, the distance adjustment can be performed with high accuracy. Moreover, since the stopper tube 23 and the protruding tube 24 are press-fitted, the distance Lx1 between the stopper tube 23 and the protruding tube 24 can be continuously adjusted, and the distance adjustment can be performed with higher accuracy. it can.

  In the present embodiment, the small lift solenoid device 20 and the large lift solenoid device 30 are arranged in this order from the one end side to the large lift solenoid device 30 and the small lift solenoid device 20, and the stopper member 33. Is provided separately from the injector body 15 and is provided on the one end side of the injector body 15 by being press-fitted into the inner surface of the injector body 15.

  As described above, since the stopper member 33 of the large lift solenoid device 30 is provided on the injector body 15, in order to adjust the distance Lx2 between the stopper member 33 of the large lift solenoid device 30 and the protruding step 34. Needs to accommodate the needle valve 16 in the injector body 15. However, according to this configuration, since the stopper member 33 is provided on the one end side of the injector body 15, the needle valve 16 is accommodated in the injector body 15 by removing the nozzle 12 and opening the one end side of the injector body 15. In this state, the distance Lx2 between the stopper member 33 and the protruding step portion 34 can be adjusted. In addition, since the stopper member 33 is press-fitted, the position of the stopper member 33 can be continuously adjusted, and the distance between the stopper member 33 and the protruding step 34 can be adjusted 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 (3)

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,
The first stopper is provided on the needle valve;
An idle running distance from the position where the first movable iron core is in contact with the first stopper when the first solenoid device is operated until it collides with the first protrusion is S1, and the first movable iron is The lift amount from the collision with the first protrusion to the contact with the first solenoid coil is L1, and the second movable iron core collides with the second protrusion when the second solenoid device is operated. A fuel injection device for a direct injection engine, wherein S1 + L1 ≧ L2 is set when a lift amount until contact with the second solenoid coil is L2. The fuel injection device for a direct injection engine according to claim 1,
Before Symbol first stopper portion and the first projecting portion is provided separately from the said needle valve, a fuel injection apparatus for a direct injection engine, characterized in that it is pressed into the outer surface of the needle valve. The fuel injection device for a direct injection engine according to claim 1 or 2,
The first solenoid device and the second solenoid device are arranged in order of the second solenoid device and the first solenoid device from the one end side,
The direct injection engine characterized in that the second stopper portion is provided separately from the injector body, and is provided on the one end side of the injector body by being press-fitted into the inner surface of the injector body. Fuel injectors.

Images