JP2010169041A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve stabilizing a behavior of a movable core so as to provide high injection performance. <P>SOLUTION: The fuel injection valve 10 comprises: a body 20 having an injection hole 22 at a tip thereof; a needle 70 controlling opening/closing of an injection hole 22; and an electromagnetic actuator 80 reciprocating the needle 70. The electromagnetic actuator 80 is composed of: a movable core 81; a coil 87; a fixed core 88; and a first spring 91 pressing the needle 70 in the valve closing direction, and a second spring 92 pressing the movable core 81 in a valve opening direction. A base-end-side end of the second spring 92 is supported on a seat part 85 of a bottom of a recess part 84 formed to a distal end of the movable core 81. The recess part 84 has a shape for keeping a non-contact state of a side wall 86 of the recess part 84 with a side part 93 of the second spring 92, during valve opening operation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel injection valve that supplies fuel to an internal combustion engine (hereinafter simply referred to as an engine).

  A first urging member that presses the movable core and the valve member in a direction in which the movable core and the valve member are movable relative to each other, and the movable core moves away from the fixed core, and a second urging member that presses the movable core toward the fixed core. And a fuel injection valve that suppresses bouncing of the movable core and the valve member when the movable core reaches the maximum lift when the movable core is attracted by the magnetic attractive force generated by the fixed core. (See Patent Document 1).

Utility Model Registration Gazette No. 2568515

  In the fuel injection valve of Patent Document 1, the structure for supporting the end portion on the proximal end side of the second urging member is formed at the base of the protruding portion protruding from the end portion on the distal end side of the movable core. It has a structure that supports.

  In this support structure, when the second urging member is inclined, there is a possibility that the side portion on the inner peripheral side of the second urging member and the side wall of the protruding portion come into contact with each other. When the movable core moves to the fixed core side in a state where the side portion on the inner peripheral side of the second urging member and the side wall of the protruding portion are in contact with each other, the radial direction intersects the moving direction of the movable core from the second urging member ( Hereinafter, a force in the radial direction) is applied to the movable core.

  Further, when the movable core moves to the fixed core side in a state where both elements are in contact, the movable core moves while the second urging member rubs against the protruding portion, so that the urging member slides to the protruding portion of the movable core. Dynamic resistance is applied, and movement of the movable core is hindered. The behavior of the movable core becomes unstable due to the influence of the radial force and sliding resistance.

  When the behavior of the movable core becomes unstable, the behavior of the valve member also becomes unstable, so that the reproducibility of the injection characteristics of the fuel injected from the injection hole is deteriorated, and the injection performance is deteriorated.

  Moreover, in order to stabilize the behavior of the movable core, there is a demand for minimizing the distance between the positions where the first and second urging members are applied with the force pressing the movable core.

  The present invention has been made in view of the above problems and demands, and an object of the present invention is to provide a fuel injection valve that stabilizes the behavior of the movable core and provides high injection performance.

According to the first aspect of the present invention, there is provided a body in which a fuel passage through which fuel flows from the base end side toward the tip end is formed, and an injection hole communicating with the fuel passage is formed at the tip end, and the fuel of the body A valve member that is installed in the passage so as to be reciprocally movable, and controls the injection and stop of fuel from the nozzle hole by intermittently connecting the fuel passage, and an electromagnetic actuator that is mounted on the body and reciprocates the valve member. In the fuel injection valve provided,
The valve member includes a valve portion that interrupts the fuel passage by being seated on the inner wall of the fuel passage on the distal end side, and a restriction portion that protrudes radially outward on the base end side of the valve portion,
The electromagnetic actuator is a movable core provided between the regulating portion and the valve portion so as to be relatively movable with the valve member. The electromagnetic actuator is in contact with the regulating portion at the proximal end, thereby allowing the valve member and the movable core to move. And a movable core having a contact portion that restricts relative movement in a direction away from each other, a coil that is provided on the proximal side of the movable core and generates a magnetic field when energized, and on the proximal side of the movable core A fixed core that generates a magnetic attractive force between the movable core and the movable core by a magnetic field generated by the coil; and a valve member that is provided closer to the base end side than the movable core and in which the movable core is away from the fixed core. A first urging member that presses the movable core, and a second urging member that is provided on the tip side of the movable core and presses the movable core toward the fixed core,
The movable core is formed so as to be recessed toward the fixed core at the end portion on the distal end side, and includes a recess having a first seat portion supporting the end portion on the proximal end side of the second urging member at the bottom portion. The movable core is attracted to the fixed core, and the valve portion is separated from the inner wall of the fuel passage and reaches the maximum lift, and the non-contact state between the side portion of the second urging member and the side wall of the recess is maintained. It is characterized by a shape like this.

  In this invention, the movable core is provided with a recess having a recess recessed toward the fixed core at the distal end and a seat portion supporting the proximal end of the second urging member at the bottom.

  And this recessed part is the non-contact between the side part of the second urging member and the side wall of the recessed part until the movable core is attracted to the fixed core and the valve part is separated from the inner wall of the fuel passage and reaches the maximum lift. The shape is such that the contact state is maintained. For this reason, even if the second urging member is inclined, the radial force due to the inclination of the second urging member is less likely to act on the movable core.

  Further, since the non-contact state of both the elements is maintained, there is no sliding resistance from the second urging member to the movable core, and the movement of the movable core is hardly hindered. For this reason, the behavior of the movable core is stabilized.

  In the present invention, the movable core has a concave portion provided at the end portion on the distal end side toward the fixed core and provided on the bottom portion with a seat portion that supports the end portion on the proximal end side of the second urging member. Thereby, the force by which the second urging member presses the movable core acts on the seat portion.

  Further, the movable core has a contact portion with which the restriction portion of the valve member comes into contact with the proximal end portion. Thereby, the force which a 1st biasing member presses a valve member and a movable core acts on a contact part via a control part. According to this configuration, the distance between the force application points of the first and second urging members in the movable core can be minimized. For this reason, the behavior of the movable core is further stabilized. As described above, according to the fuel injection valve adopting the configuration of the present invention, the behavior of the movable core can be stabilized and the injection performance can be improved.

  In the invention according to claim 2, the body is formed in the inner wall so as to be recessed toward the tip, and the receiving recess having the second seat portion supporting the end portion on the tip side of the second urging member on the bottom portion. It is characterized by having.

  In the present invention, the body is provided with a housing recess that is formed in the inner wall so as to be recessed toward the tip, and has a seat portion that supports the tip of the second biasing member on the bottom. Thereby, the second urging member can be arranged at a predetermined position. For this reason, since it can suppress that the 2nd biasing member is arrange | positioned in the position biased with respect to the movable core, the behavior of a movable core can be stabilized and injection performance can be improved.

  The invention according to claim 3 is characterized in that the recess and the accommodating recess are formed in a cylindrical shape, and the inner diameter of the recess is larger than the inner diameter of the accommodating recess. In this invention, since the inner diameter of the recess is larger than the inner diameter of the housing recess, the non-contact state between the side portion of the second urging member and the side wall of the recess is ensured.

  In the invention according to claim 4, the movable core is provided with a support hole through which the valve member is inserted and supported so as to be movable relative to the valve member, and the recess is disposed on the same axis as the support hole. Further, an extension portion of the support hole that protrudes from the seat portion of the concave portion toward the front end side is formed.

  In this invention, since the extension part of the support hole provided in the movable core that protrudes from the seat part of the concave part to the tip side is formed in the concave part, the support length in the movable core that supports the valve member is easily secured. can do.

It is sectional drawing which shows the structure of the fuel injection valve by 1st Embodiment of this invention. It is sectional drawing which shows the principal part of the fuel injection valve shown in FIG. It is sectional drawing which shows the principal part of the fuel injection valve by 2nd Embodiment of this invention.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the component corresponding in each embodiment.

(First embodiment)
(Basic configuration)
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 shows the structure of a fuel injection valve according to a first embodiment of the present invention. FIG. 2 shows a main part of the fuel injection valve shown in FIG.

  A fuel injection valve 10 shown in FIG. 1 is an injection valve mounted on a direct injection gasoline engine. The fuel injection valve 10 may be mounted not only on the direct injection gasoline engine but also on a port injection gasoline engine, a diesel engine, or the like. When mounted on a direct injection gasoline engine, the fuel injection valve 10 is mounted on a cylinder head (not shown).

  The fuel injection valve 10 includes a body 20, a needle 70, an electromagnetic actuator 80, and the like.

  The body 20 is formed in a rod shape and holds functional parts necessary for fuel injection control. A fuel passage 21 through which fuel flows from the base end side toward the tip end is formed inside the body 20. An injection hole 22 communicating with the fuel passage 21 is formed at the tip of the body 20.

  The needle 70 is installed in the fuel passage 21 of the body 20 so as to be capable of reciprocating. The needle 70 controls the injection of fuel from the injection hole 22 by intermittently connecting the fuel passage 21. When the needle 70 is separated from the inner wall of the fuel passage 21, the fuel passage 21 is opened and fuel is injected from the injection hole 22. When the needle 70 is seated on the inner wall of the fuel passage 21, the fuel passage 21 is blocked and fuel injection from the injection hole 22 is stopped.

  The electromagnetic actuator 80 is an actuator that is attached to the body 20, generates power by switching between energization and non-energization, and reciprocally moves the needle 70 with the generated power. When the electromagnetic actuator 80 is energized, the electromagnetic actuator 80 moves the needle 70 to the proximal end side and causes the needle 70 to be separated from the inner wall of the fuel passage 21. By stopping energization of the electromagnetic actuator 80, the electromagnetic actuator 80 moves the needle 70 to the distal end side and seats the needle 70 on the inner wall of the fuel passage 21.

  Hereinafter, each element will be described in detail.

  The body 20 includes a pipe 30, a nozzle holder 40, a nozzle body 50, and the like. The pipe 30, the nozzle holder 40, and the nozzle body 50 are all formed in a cylindrical shape, and are assembled so that the axis of each element is arranged on one axis.

  The pipe 30 is a metal cylindrical member having an inner diameter that is substantially the same in the axial direction. The pipe 30 forms a part of the fuel passage 21 inside. The pipe 30 has a magnetic portion 31 and a nonmagnetic portion 32 from the proximal end side toward the distal end side. The magnetic part 31 and the nonmagnetic part 32 are integrally connected by, for example, laser welding. The pipe 30 may be formed by magnetizing or demagnetizing a part of the cylindrical object by heat processing or the like. Further, the pipe 30 may be formed of only a magnetic material, and the cross-sectional area at the position corresponding to the non-magnetic portion 32 may be made smaller than other portions.

  An inlet member 100 is installed at the proximal end of the pipe 30. The inlet member 100 is connected to a fuel pipe (not shown) and introduces fuel into the fuel passage 21. In the present embodiment, the fuel whose pressure is increased to 4 MPa to 20 MPa is introduced into the inlet member 100 through the fuel pipe. The inlet member 100 is fixed to the pipe 30 by being press-fitted into the inner wall of the pipe 30 and then being welded. The inlet member 100 has a filter 101 that catches foreign substances contained in the fuel. In addition, an O-ring 102 that fills the gap between the fuel pipe and the fuel pipe is provided on the outer peripheral side of the inlet member 100.

  A nozzle holder 40 is installed at the end of the pipe 30 on the tip side. The nozzle holder 40 is formed in a cylindrical shape from a magnetic material. The inner diameter of the base end side of the nozzle holder 40 is substantially the same as the inner diameter of the pipe 30. The nozzle holder 40 is fixed to the pipe 30 by welding or the like.

  The inner diameter on the distal end side of the nozzle holder 40 is smaller than the inner diameter on the proximal end side. A nozzle body 50 is installed at the end of the nozzle holder 40 on the front end side. The nozzle holder 40 and the nozzle body 50 form a part of the fuel passage 21 inside. The fuel passage 21 formed by the pipe 30 and the fuel passage 21 formed by the nozzle holder 40 and the nozzle body 50 communicate with each other.

  The nozzle body 50 is a cylindrical member having a bottom, and is fixed to the inner wall of the nozzle holder 40 by either press fitting or welding, or by welding after press fitting. The bottom part of the nozzle body 50 forms a conical surface whose inner diameter becomes smaller toward the tip. A valve seat 51 on which the needle 70 is seated is formed on the conical surface. An injection hole 22 is formed in the conical surface on the tip side of the valve seat 51. The nozzle hole 22 communicates with the fuel passage 21.

  The needle 70 includes a main body portion 71, a valve portion 72, and a restriction portion 73. The needle 70 is formed in a rod shape from a metal material, and is installed on the axis of the pipe 30, the nozzle holder 40 and the nozzle body 50 so as to be reciprocally movable.

  The valve portion 72 is provided at an end portion on the distal end side of the main body portion 71 and has a shape that can be seated on the valve seat 51 from the proximal end side. When the valve portion 72 is separated from the valve seat 51, the fuel passage 21 is opened, the fuel passage 21 and the injection hole 22 communicate with each other, and fuel is injected from the injection hole 22. When the valve portion 72 is seated on the valve seat 51, the fuel passage 21 is shut off, the communication between the fuel passage 21 and the injection hole 22 is cut off, and the fuel injection from the injection hole 22 is stopped.

  The restriction portion 73 is a portion that is provided at an end portion on the proximal end side of the main body portion 71 and protrudes radially outward from the main body portion 71. The restricting portion 73 can come into contact with a contact portion 83 of the movable core 81 described later, and is a portion that restricts relative movement between the movable core 81 and the needle 70.

  A communication passage 74 is formed in the main body portion 71 and the restriction portion 73 to connect the fuel passage 21 formed in the pipe 30 portion and the fuel passage 21 formed in the nozzle holder 40 portion. The communication passage 74 extends in a radial direction from the first series passage 75 extending along the axial center line of the needle 70 from the end portion on the base end side of the restriction portion 73 to the middle of the main body portion 71, and A second communication path 76 that communicates the first series path 75 and the outer wall of the main body 71 is provided. As a result, the fuel introduced from the inlet member 100 into the fuel passage 21 in the pipe 30 portion flows into the fuel passage 21 in the nozzle holder 40 portion via the communication passage 74.

  The electromagnetic actuator 80 includes a movable core 81, a coil 87, a fixed core 88, a first spring 91, a second spring 92, a housing 90, an upper housing 95, and the like.

  The movable core 81 is formed in a cylindrical shape from a magnetic material, and is disposed between the restriction portion 73 and the valve portion 72 of the needle 70 so as to be reciprocally movable inside the pipe 30 and the nozzle holder 40. In the movable core 81, the outer wall of the movable core 81 is slidably in contact with the pipe 30 and the inner wall of the nozzle holder 40. Thereby, the movable core 81 can reciprocate in the axial direction within the pipe 30 and the nozzle holder 40.

  The movable core 81 has a support hole 82 that supports the needle 70 so as to be relatively movable at the center. The inner diameter of the support hole 82 is larger than the outer diameter of the main body 71 of the needle 70 and smaller than the outer diameter of the restricting portion 73. As a result, the needle 70 can reciprocate in the axial direction within the movable core 81.

  In addition, the movable core 81 has a contact portion 83 at the proximal end that restricts relative movement in a direction in which the needle 70 and the movable core 81 are separated from each other by contacting the restriction portion 73. In a state where the valve portion 72 of the needle 70 is seated on the valve seat 51, the movable core 81 can be relatively moved on the tip side with respect to the restricting portion 73. Even when the restricting portion 73 of the needle 70 comes into contact with the contact portion 83 of the movable core 81, when the movable core 81 moves to the proximal end side, the needle 70 moves to the proximal end side together with the movable core 81. As a result, the valve portion 72 of the needle 70 is separated from the valve seat 51.

  The coil 87 is formed by rotating an electric wire around the bobbin shaft center on the outer periphery of a bobbin which is a resin-made cylindrical member, and generates a magnetic field by energizing the electric wire. The coil 87 is installed outside the pipe 30. The end of the electric wire is connected to the terminal 111 of the connector 110 provided on the proximal end side of the coil 87. The terminal 111 is electrically connected to an external control device, and the coil 87 is energized through the terminal 111.

  The fixed core 88 is formed in a cylindrical shape from a magnetic material, and is installed on the proximal end side of the movable core 81. The fixed core 88 is fixed to the inner wall of the pipe 30 by press fitting or the like. In the present embodiment, the fixed core 88 is firmly fixed by welding after being press-fitted into the inner wall of the pipe 30. A vertical hole 89 extending in the axial direction is formed at the center of the fixed core 88. The vertical hole 89 allows the fuel introduced from the inlet member 100 to flow.

  A first spring 91 is installed on the proximal end side of the restricting portion 73 of the needle 70. The first spring 91 is a spring that is wound spirally around a linear elastic material, and is accommodated in the vertical hole 89 of the fixed core 88. An end portion on the distal end side of the first spring 91 is supported by a seat portion 77 formed at an end portion on the proximal end side of the restriction portion 73.

  The proximal end of the first spring 91 is supported by a cylindrical adjuster pipe 113 that is press-fitted into the vertical hole 89. The first spring 91 is disposed between the restricting portion 73 and the adjuster pipe 113 in a state where the first spring 91 is compressed in the axial direction, and the needle 70 and the movable core 81 are moved away from the fixed core 88, that is, the valve. The part 72 is pressed in the direction in which the valve seat 51 is seated. Hereinafter, the direction in which the valve portion 72 is seated on the valve seat 51 is referred to as the valve closing direction, and the opposite direction is defined as the valve opening direction.

  A second spring 92 is installed on the tip side of the movable core 81. The second spring 92 is a spring spirally wound around a linear elastic material, and is accommodated in the nozzle holder 40.

  The nozzle holder 40 is formed in the inner wall of the nozzle holder 40 so as to be recessed toward the distal end side, and an accommodation recessed portion 41 having a seat portion 42 that supports the end portion on the distal end side of the second spring 92 at the bottom portion. I have. The accommodating recess 41 is formed in a cylindrical shape, and the inner diameter d <b> 2 of the accommodating recess 41 is substantially the same as or larger than the outer diameter of the second spring 92. For this reason, the movement of the second spring 92 in the radial direction is restricted by the side wall 43 of the housing recess 41. The base end side end of the second spring 92 is supported by a seat portion 85 formed at the bottom of the recess 84 formed in the movable core 81.

  The recessed portion 84 is formed so as to be recessed toward the fixed core 88 from the end portion on the distal end side of the movable core 81. The recess 84 is formed in a cylindrical shape, and the inner diameter d1 thereof is larger than the inner diameter d2 of the housing recess 41. The second spring 92 is disposed between the concave portion 84 of the movable core 81 and the accommodating concave portion 41 of the nozzle holder 40 while being compressed in the axial direction, and presses the movable core 81 toward the fixed core 88.

  Here, the pressing force of the first spring 91 is larger than the pressing force of the second spring 92. For this reason, when the coil 87 is not energized, the needle 70 and the movable core 81 are always pressed in the valve closing direction by the first spring 91. At this time, the contact portion 83 of the movable core 81 is in contact with the restricting portion 73 of the needle 70 by the pressing force of the second spring 92.

  The fuel that has flowed into the inlet member 100 flows into the communication passage 74 of the needle 70 via the vertical hole 89 of the fixed core 88 and the adjuster pipe 113. The fuel that has flowed into the communication path 74 is discharged from the second communication path 76 to the fuel path 21 in the nozzle holder 40 portion outside the needle 70 and reaches the nozzle hole 22.

  The housing 90 is formed of a magnetic material into a cylindrical shape, and is installed outside the pipe 30 and the nozzle holder 40. The inner diameter of the housing 90 is larger than the outer diameters of the pipe 30 and the nozzle holder 40 and is large enough to form a gap between the housing 90 and the pipe 30 and the nozzle holder 40. A coil 87 is installed in the formed gap.

  The length of the housing 90 in the axial direction is large enough to straddle the nonmagnetic portion 32 of the pipe 30. The end portion on the front end side of the housing 90 is fixed to the nozzle holder 40 by welding or the like.

  The upper housing 95 is formed in a disk shape from a magnetic material. A part of the upper housing 95 is notched, and a part of the connector 111 is disposed in the notched part. The upper housing 95 is installed on the proximal end side of the coil 87, and the outer peripheral side is in contact with the housing 90 and the inner peripheral side is in contact with the magnetic part 31 of the pipe 30.

  Here, when the coil 87 is energized, a magnetic field corresponding to the direction of the current flowing through the wire of the coil 87 is generated inside and outside the coil 87. When a magnetic field is generated around the coil 87, magnetic flux flows through the fixed core 88, the movable core 81, the nozzle holder 40, the housing 90, the upper housing 95, and the magnetic part 31, and a magnetic circuit is formed. When the magnetic circuit is formed, a magnetic attraction force that is a force by which the fixed core 88 attracts the movable core 81 is generated between the fixed core 88 and the movable core 81.

  The configuration of the fuel injection valve 10 has been described above. Next, the operation of the fuel injection valve 10 will be described.

  When the coil 87 is energized, a magnetic attractive force is generated between the fixed core 88 and the movable core 81. The sum of the magnetic attraction force and the pressing force of the second spring 92 is the pressing force of the first spring 91, the needle pressing force toward the distal end due to the fuel pressure, the weight of the movable core 81, and the movable core 81 and the pipe 30. When the sum of the sliding resistance forces becomes larger, the movable core 81 moves toward the fixed core 88. At this time, since the contact portion 83 of the movable core 81 is in contact with the restriction portion 73 of the needle 70, the needle 70 also moves together with the movable core 81 toward the fixed core 88, that is, in the valve opening direction.

  As a result, the valve portion 72 of the needle 70 is separated from the valve seat 51. The movement in the valve opening direction moves until the movable core 81 contacts the fixed core 88. At this time, the needle 70 has moved to the maximum lift position.

  When the movable core 81 is attracted to the fixed core 88 and the valve portion 72 of the needle 70 is separated from the valve seat 51, the fuel passage 21 and the injection hole 22 communicate with each other, and the fuel in the fuel passage 21 is injected from the injection hole 22. Is done.

  When the coil 87 is switched from the energized state to the non-energized state, no magnetic attractive force is generated between the fixed core 88 and the movable core 81. For this reason, the needle 70 moves in the valve closing direction by the pressing force of the first spring 91. At this time, the contact portion 83 of the movable core 81 is in contact with the restriction portion 73 of the needle 70. Therefore, the movable core 81 also moves in the valve closing direction. Since the needle 70 moves in the valve closing direction, the valve portion 72 is seated on the valve seat 51, the fuel passage 21 is blocked, and fuel is not injected from the injection hole 22.

  In the present embodiment, the movable core 81 and the needle 70 are relatively movable. Furthermore, the movable core 81 and the needle 70 move together in the valve opening direction when the contact portion 83 contacts the restriction portion 73. These move until the movable core 81 contacts the fixed core 88. When the movable core 81 contacts the fixed core 88, the movable core 81 rebounds in the valve closing direction.

  Since the movable core 81 and the needle 70 can move relative to each other, the movable core 81 rebounds in the valve closing direction, but the needle 70 continues to move in the valve opening direction due to inertial force. Thereby, the rebound of the needle 70 in the valve closing direction is suppressed, and the irregular change in the distance between the valve portion 72 and the valve seat 51 due to the rebound of the needle 70 is reduced. As a result, the fuel injection from the nozzle hole 22 is stabilized and the injection performance is improved.

  Further, when the movable core 81 rebounds in the valve closing direction by the fixed core 88, the contact portion 83 is separated from the restricting portion 73. For this reason, the pressing force of the second spring 92 acting on the needle 70 via the movable core 81 does not act. At this time, only the pressing force of the first spring 91 acts on the needle 70.

  That is, when the movable core 81 and the needle 70 are separated, the force acting on the needle 70 becomes only the pressing force of the first spring 91, and the force for moving the needle 70 in the valve closing direction increases. Therefore, excessive movement of the needle 70 in the valve opening direction is suppressed.

  Further, when the force acting on the needle 70 is only the pressing force of the first spring 91, the needle 70 is restrained from moving in the valve opening direction and starts moving in the valve closing direction. On the other hand, the movable core 81 bounced back in the valve closing direction starts to move again in the valve opening direction by the magnetic attractive force and the pressing force of the second spring 92. For this reason, the needle 70 moving in the valve closing direction collides with the movable core 81 moving in the valve opening direction. This collision cancels out the momentum of the needle 70 and the movable core 81 and restricts the movement of the needle 70 in the valve closing direction.

  Thus, by making the movable core 81 and the needle 70 relatively movable, the needle 70 rebounds when the valve is opened as compared with the type in which the movable core 81 and the needle 70 are integrated. Can be quickly converged. As a result, the fuel injection from the nozzle hole 22 is stabilized and the injection performance is improved.

  When energization of the coil 87 is stopped, the magnetic attraction force disappears, so that the needle 70 and the movable core 81 are moved in the valve closing direction by the first spring 91. As a result, the valve portion 72 of the needle 70 is seated on the valve seat 51 and fuel injection from the nozzle hole 22 is stopped.

  At this time, the movable core 81 and the needle 70 move in the valve closing direction against the pressing force of the second spring 92 by the pressing force of the first spring 91. When the valve portion 72 of the needle 70 is seated on the valve seat 51, the needle 70 tries to rebound in the valve opening direction due to an impact at the time of seating.

  Here, since the movable core 81 and the needle 70 are relatively movable, even when the valve portion 72 is seated on the valve seat 51, the movable core 81 continues to move in the valve closing direction due to inertial force. At this time, the contact portion 83 of the movable core 81 is separated from the restriction portion 73 of the needle 70. Therefore, the force acting on the needle 70 is only the pressing force of the first spring 91. As a result, the mass of the movable part on which the first spring 91 acts becomes only the needle 70 and decreases.

  Since the inertial force of the movable part is reduced, the rebound of the needle 70 in the valve opening direction is suppressed. Therefore, even when the valve is closed, the rebound of the needle 70 can be quickly converged.

  According to the configuration described above, the operation of the needle 70 can be stabilized when the valve is opened and closed, the fuel injection from the injection hole 22 can be stabilized, and the injection performance can be improved.

(Characteristic part)
Next, the characteristic part of this embodiment is demonstrated in detail using FIG.

  A recessed portion 84 that is recessed toward the fixed core 88 is formed at the end portion on the distal end side of the movable core 81. A seat portion 85 that supports an end portion on the proximal end side of the second spring 92 is formed on the bottom portion of the concave portion 84. The pressing force of the second spring 92 acts on the seat portion 85. The recessed part 84 and the accommodation recessed part 41 are arrange | positioned coaxially. Furthermore, the inner diameter d1 of the recess 84 is larger than the inner diameter d2 of the housing recess 41.

  In addition, the concave portion 84 is a side portion on the outer side of the second spring 92 until the movable core 81 is attracted to the fixed core 88 and the valve portion 72 of the needle 70 is separated from the valve seat 51 and reaches the maximum lift. 93 and the side wall 86 of the recess 84 are maintained in a non-contact state. That is, when the fuel injection valve 10 is opened, the side portion 93 on the outer side of the second spring 92 is in contact with the recess 84 in the movable core 81 until the valve portion 72 is separated from the valve seat 51 and reaches the maximum lift. Do not touch the side wall 86 at all.

  According to the present embodiment described above, since the movable core 81 has the concave portion 84 having the shape as described above, the second spring 92 is installed in the pipe 30 and the nozzle holder 40 so as to be inclined in the radial direction. Even if the second spring 92 is tilted in the radial direction, the radial force due to the tilt of the second spring 92 hardly acts on the movable core 81 via the side wall 86 of the recess 84.

  Moreover, since the non-contact state of both 81 and 92 is maintained, the sliding resistance given to the movable core 81 by the contact of the second spring 92 and the recess 84 disappears, and the movable core 81 moves in the axial direction. It becomes difficult to be disturbed. For this reason, the behavior of the movable core 81 is stabilized.

  In addition, according to the present embodiment, the base end side end of the second spring 92 is supported by the seat 85 formed at the bottom of the recess 84 in the movable core 81. For this reason, the pressing force of the second spring 92 acts on the seat 85. On the other hand, the end portion on the distal end side of the first spring 91 is supported by a seat portion 77 formed on the proximal end side of the restriction portion 73 of the needle 70.

  Further, in a state where the contact portion 83 of the movable core 81 and the restriction portion 73 of the needle 70 are in contact, the pressing force of the first spring 91 acts on the contact portion 83 of the movable core 81 via the restriction portion 73. According to this configuration, the distance between the action points of the first and second springs 91 and 92 acting on the movable core 81 can be minimized. For this reason, the behavior of the movable core 81 is further stabilized.

  As described above, according to the fuel injection valve 10 adopting the movable core 81 having the structure as described in the present embodiment, the behavior of the movable core 81 can be stabilized, so that the movable core 81 moves together. The behavior of the needle 70 can also be stabilized, and the reproducibility of the operation of the movable core 81 and the needle 70 can be ensured. As a result, the injection characteristics such as the injection amount, injection rate, and injection timing of the fuel injected from the injection hole 22 can be stabilized, and the injection performance of the fuel injection valve 10 is enhanced.

  In the present embodiment, the distance between the points of action of the pressing forces of the first and second springs 91 and 92 on the movable core 81 is reduced by forming a recess at the proximal end of the movable core 81. This is not performed by the above, but is performed by the concave portion 84 formed at the end of the movable core 81 on the front end side. According to this, the distance can be made small while securing the area facing the fixed core 88 in the movable core 81. In addition, since the mass of the movable core 81 is reduced by forming the recess 84 in the movable core 81, the operation responsiveness of the needle 70 is improved.

  Here, if the length of the concave portion 84 in the depth direction of the movable core 81 is excessively increased in order to reduce the distance, the length of the support hole 82 is inevitably reduced. When this length becomes small, the length that the movable core 81 supports the needle 70 becomes small. On the contrary, the behavior of the needle 70 may become unstable. Therefore, it is necessary to keep the depth of the recess 84 formed in the movable core 81 to a certain level.

  In the present embodiment, the recess 84 is formed at the end of the movable core 81 on the tip side. If the inner diameter is increased without increasing the length of the recess 84 in the depth direction, the recess 84 has a certain volume without sacrificing the length of the support hole 82 and the area of the movable core 81 facing the fixed core 88. More can be removed. That is, the weight of the movable core 81 can be reduced without reducing the stability of the needle 70 and the magnetic attraction force.

  Also, since the nozzle holder 40 is formed with an accommodation recess 41 for accommodating the end of the second spring 92 on the front end side, the second spring 92 can be moved in a predetermined position, for example, the axis of the second spring 92. It can be arranged at a position where the axis of the core 81 overlaps.

  According to this, the pressing force of the second spring 92 acts on the movable core 81 evenly. For this reason, the behavior of the movable core 81 is stabilized. As a result, the injection performance of the fuel injection valve 10 is enhanced. Further, since the inner diameter d1 of the recess 84 is larger than the inner diameter d2 of the housing recess 41, the non-contact state between the outer side portion 93 of the second spring 92 and the side wall 86 of the recess 84 is ensured.

  In the present embodiment, the needle 70 corresponds to a “valve member” recited in the claims. In the present embodiment, the first spring 91 corresponds to the “first biasing member” recited in the claims, and the second spring 92 corresponds to the “second biasing member” recited in the claims. Equivalent to. Further, the seat 85 of the recess 84 corresponds to the “first seat” described in the claims, and the seat 42 of the housing recess 41 corresponds to the “second seat” described in the claims. . Moreover, the body 20 of this embodiment is comprised from the pipe 30, the nozzle holder 40, and the nozzle body 50, and is corresponded to the "body" as described in a claim.

(Second Embodiment)
The second embodiment of the present invention is a modification of the first embodiment. As shown in FIG. 3, the second embodiment is different from the first embodiment in that an extension 82 a that extends the support hole 82 toward the distal end side is formed in the recess 84 of the movable core 81. Also in this embodiment, the outer side portion 93 and the inner side portion 94 of the second spring 92 are kept out of contact with the side wall 86 of the recess 84 and the outer side wall 82b of the extension portion 82a, respectively. .

  As a result, the length of the movable core 81 that supports the needle 70 is easily ensured to some extent regardless of the depth of the recess 84. For this reason, even if the concave portion 84 that is recessed toward the fixed core 88 is formed in the movable core 81, the behavior of the needle 70 and the movable core 81 does not become unstable.

  DESCRIPTION OF SYMBOLS 10 Fuel injection valve, 20 Body, 21 Fuel passage, 22 Injection hole, 30 Pipe, 40 Nozzle holder, 41 Containing recessed part, 42 Seat part (2nd seat part), 43 Side wall, 50 Nozzle body, 51 Valve seat, 70 Needle ( Valve member), 72 valve portion, 73 regulating portion, 77 seat portion, 80 electromagnetic actuator, 81 movable core, 82 support hole, 82a extension portion, 83 contact portion, 84 recess portion, 85 seat portion (first seat portion), 86 Side wall, 87 coil, 88 fixed core, 90 housing, 91 first spring (first urging member), 92 second spring (second urging member), 93 side, 100 inlet member, 110 connector, 113 adjuster pipe

Claims (4)

A body in which a fuel passage through which fuel flows from the base end side to the tip is formed inside, and an injection hole communicating with the fuel passage is formed at the tip;
A valve member that is installed in the fuel passage of the body so as to be reciprocally movable, and that controls the injection and stop of the fuel from the nozzle hole by intermittently connecting the fuel passage;
In a fuel injection valve comprising: an electromagnetic actuator mounted on the body and reciprocatingly moving the valve member;
The valve member is
A valve portion for intermittently connecting the fuel passage by being seated on the inner wall of the fuel passage on the tip side;
A restricting portion that protrudes radially outward on the base end side of the valve portion, and
The electromagnetic actuator is
A movable core provided between the regulating portion and the valve portion so as to be relatively movable with the valve member, and is movable with the valve member by contacting the regulating portion at a base end side end portion. A movable core having a contact portion that regulates relative movement in a direction in which the core is separated from each other;
A coil that is provided on the base end side of the movable core and generates a magnetic field when energized;
A fixed core that is provided on the base end side of the movable core and generates a magnetic attraction force between the movable core and a magnetic field generated by the coil;
A first biasing member that is provided on a proximal end side with respect to the movable core, and that presses the valve member and the movable core in a direction in which the movable core is separated from the fixed core;
A second urging member that is provided on the tip side of the movable core and presses the movable core toward the fixed core,
The movable core includes a recess having a first seat portion that is formed to be recessed toward the fixed core at an end portion on a distal end side and that supports an end portion on the proximal end side of the second urging member at a bottom portion. ,
The concave portion is configured such that the movable core is attracted to the fixed core, the valve portion is separated from the inner wall of the fuel passage, and reaches the maximum lift until the side of the second urging member and the concave portion A fuel injection valve having a shape that maintains a non-contact state with a side wall.   The body includes an accommodation recess having a second seat portion formed on the inner wall so as to be recessed toward the tip and supporting a tip of the second biasing member on the bottom. The fuel injection valve according to claim 1. The concave portion and the accommodating concave portion are formed in a cylindrical shape,
The fuel injection valve according to claim 2, wherein an inner diameter of the recess is larger than an inner diameter of the housing recess. The movable core includes a support hole through which the valve member is inserted and supported so as to be relatively movable with the valve member;
The recess is installed on the same axis as the support hole,
The fuel injection valve according to any one of claims 1 to 3, wherein an extension portion of the support hole is formed in the concave portion so as to protrude from the seat portion of the concave portion toward the front end side.

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