JP2006250122A - Fuel injection valve and assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve having two movable cores and a function of making the lift of a needle variable by regulating an axial displacement of one of the movable cores by the other movable core and improving the productivity. <P>SOLUTION: The fuel injection valve comprises a cylindrical member 18 serving as a casing, the needle 30 provided in the casing, separating from and seating to a valve seat 14, the first movable core 50 axially displaceable along with the needle, the second movable core 60 regulating the displacement of the first movable core and axially displaceable, a drive coil capable of applying magnetic force to the first and second movable cores and a magnetizing member 17, 80 as an attraction member for attracting the second movable core, wherein the lift of the needle is made variable by making the displacement of the first movable core variable. The fuel injection valve comprises a housing 15 which is provided in the casing, receives and unitizes the second movable core and a magnetizing member 18. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection valve and an assembly method.

  For example, in a fuel injection device that directly or indirectly injects fuel into a combustion chamber of an internal combustion engine, a needle as a valve member that is seated on and separated from a valve seat is used as the needle in order to accurately inject and stop fuel injection. 2. Description of the Related Art A fuel injection valve that is connected to and separated from an attraction member by a magnetic attraction force through a movable core that is connected and cooperates in an axial direction is known. This type of fuel injection valve has two movable cores and switches the injection / spray characteristics in two stages in order to switch the injection / spray characteristics of the injection such as the spray shape in accordance with the operating state of the internal combustion engine. Yes (see Patent Document 1).

In Patent Document 1, as the two movable cores, a second movable core as a movable stopper is provided separately from the movable core, and the lift amount of the needle is variable according to the axial position of the second movable core. To change spraying and spraying characteristics. In this technique, the axial position of the second movable core is determined by the position where the second movable core is attracted to the permanent magnet side by the acting force of the electromagnetic force generated in the coil and the magnetic force of the permanent magnet, 2 The movable core is switched to a low lift position that is a predetermined distance away from the permanent magnet.
JP 2004-353651 A

  In the above-mentioned Patent Document 1, it is necessary to adjust the air gap between the second movable core and the permanent magnet when setting the lift amount of the needle. As this adjustment method, for example, the second movable core having different thickness or It is conceivable to assemble the permanent magnet while appropriately selecting it, or to adjust the axial positions of the second movable core and the permanent magnet in the fuel injection valve as appropriate.

  However, when the above-described flow rate adjustment method is applied, there is a possibility that assembling time may be required by preparing a large number of parts for selective assembly or repeatedly attaching / detaching the permanent magnet in order to obtain an optimal air gap.

  The present invention has been made in view of such circumstances, and an object of the present invention is to have two movable cores, and by using one movable core to regulate the amount of axial movement of the other movable core, the needle It is an object of the present invention to provide a fuel injection valve and an assembling method capable of improving the productivity in a device having a function of making the lift amount variable.

  In order to achieve the above object, the present invention comprises the following technical means.

In the invention according to any one of claims 1 to 9, a casing, a needle provided in the casing and separated and seated on the valve seat, a first movable core provided in the casing and movable in the axial direction together with the needle, The second movable core provided in the casing and restricting the movement amount of the first movable core and movable in the axial direction, and the drive provided in the casing and capable of applying a magnetic force to the first and second movable cores A needle lift is provided by including a coil and a suction member that is provided in the casing and sucks the second movable core, and makes the amount of movement of the first movable core variable according to the axial position of the second movable core. In the fuel injection valve that makes the amount variable,
It is provided with the housing which is provided in the casing and accommodates the 2nd movable core and the attraction | suction member, and unitizes it.

  As a result, the air gap between the second movable core and the suction member can be adjusted to a predetermined gap amount at the unit stage before being incorporated into the fuel injection valve body. There is no need to prepare many.

  Furthermore, since the amount of axial movement of the second movable core can be managed by the unit, the assembly time of the fuel injection valve can be reduced.

  In the invention according to claim 2, the inner periphery of the housing has a locking portion for restricting the movement of the second movable core on the side opposite to the suction member, and the suction member is press-fitted into the inner periphery. It is characterized by that.

  According to this, the amount of axial movement of the second movable core can be determined by press-fitting the suction member into the housing.

  The invention according to claim 3 is characterized in that the unit is press-fitted into the casing.

  According to this, the casing can accommodate the first movable core, the second movable core, and the suction member therein, and the unit is press-fitted into the casing, that is, the fuel injection valve main body. Thereby, the lift amount of the needle can be adjusted by press-fitting a unit in which the axial movement amount of the second movable core is adjusted in advance into the fuel injection valve body.

  According to a fourth aspect of the present invention, the second movable core includes a biasing member that biases the second movable core in the seating direction of the needle, and the biasing member is formed so as to be able to be inserted into the suction member. Yes.

  According to this, after the unit in which the amount of axial movement of the second movable core is adjusted in advance is inserted and fixed in the fuel injection valve body, the biasing member is provided so as to apply a predetermined biasing force to the second movable core in the unit. It can be inserted into the unit.

  According to the fifth aspect of the present invention, the second movable core is provided with a biasing member that biases the second movable core in the needle seating direction, and the biasing member is sandwiched between the second movable core and the suction member. It is characterized by being contained.

  Thereby, the second movable core, the urging member, and the suction member are accommodated in the housing and unitized, so that the amount of axial movement of the second movable core and the urging load of the urging member are reduced at the unit stage. Assembly management is possible.

  Further, the invention described in claim 6 is characterized in that the urging member is provided on the outer peripheral portion of the second movable core.

  In general, when the second movable core is magnetically attracted to the attraction member using the magnetic force generated in the drive coil, the casing, the attraction member, and the second from the drive coil disposed on the outer peripheral side of the casing such as a cylindrical member, for example. In addition to the flow of magnetic flux flowing to the movable core, a leakage magnetic flux that flows directly from the casing to the second movable core may occur.

  On the other hand, in the invention described in claim 6, since the urging member is provided on the outer peripheral portion of the second movable core, it is possible to provide a gap between the casing and the second movable core. Therefore, leakage of magnetic flux that flows directly from the casing to the second movable core can be prevented.

  Further, the invention according to claim 7 is characterized in that a step is provided between the outer peripheral portion and the inner periphery of the casing, and the urging member is mounted on the step.

  According to this, a step is provided between the outer peripheral portion and the inner periphery of the casing, and the urging member is attached to the step, so that the urging member can be attached to urge the second movable core, A gap is reliably provided between the casing and the second movable core.

  In the inventions according to claims 8 to 9, the attraction member is a magnetized member capable of attracting the second movable core to the side opposite to the first movable core according to the direction of the magnetic force of the drive coil. .

  For example, when switching the axial position of the second movable core and switching the lift amount of the needle between a low lift state and a high lift state, a magnetic force is generated by supplying current to the suction member as a method of driving the second movable core, for example. When a driving member such as a coil is used, power consumption for driving the driving member is required in addition to the power consumption for driving the driving coil.

  On the other hand, in the inventions according to claims 8 to 9, a magnetizing member such as a permanent magnet capable of attracting the second movable core to the side opposite to the first movable core according to the direction of the magnetic force of the drive coil is used as the attracting member. Therefore, the power consumption of the entire system including the fuel injection valve that switches the lift amount of the needle can be reduced.

  In the invention according to claim 9, the magnetizing member is preferably composed of a permanent magnet and a magnetic body capable of accommodating the permanent magnet therein. According to this, the magnetic body is disposed between the second movable core and the permanent magnet. Thereby, for example, when the magnetic field (direction of magnetic force) generated in the first movable core and the second movable core by energization of the drive coil is opposite to the magnetic field of the permanent magnet, the flow of magnetic flux in the drive coil is The magnetic flux does not act directly on the permanent magnet itself, which acts as a magnetic resistance, but acts on the magnetic body provided between the permanent magnet and the second movable core. Can be removed. Therefore, the electromagnetic force generated in the drive coil can be used efficiently.

  Furthermore, as a method of managing the amount of insertion of the magnetized member into the unit, only a magnetic material is inserted into the housing, and after determining the amount of insertion, a permanent magnet is assembled into the magnetic body, or the permanent magnet is incorporated into the magnetic body. The magnetic body can also be assembled in the housing in the assembled state.

In invention of Claim 10 thru | or 13, it is provided with the needle which leaves | separates and seats on a valve seat, two movable cores, a suction member, and the cylindrical member which accommodates these members, Among them, it is used for a fuel injection valve that varies the amount of movement of the first movable core according to the axial position of the second movable core on the suction member side, and the lift amount that is separated from the valve seat of the needle is varied. In the method of assembling the fuel injection valve for adjusting the axial movement amount of the second movable core,
Forming a housing for accommodating the second movable core and the suction member;
The housing accommodates the second movable core and the suction member to form a unit,
The axial movement amount of the second movable core is adjusted by a press-fitting amount for press-fitting the suction member into the housing.

  According to this, as an assembling method for adjusting the amount of axial movement of the second movable core, a housing for accommodating the second movable core and the suction member is formed, and the second movable core and the suction member are accommodated in this unit. In this unit, the axial movement amount of the second movable core can be adjusted by the press-fitting amount of the suction member into the housing. Therefore, the amount of axial movement of the second movable core can be adjusted at the unit stage before being incorporated into the fuel injection valve, and productivity can be improved.

  In the invention according to claim 11, when the second movable core and the suction member are accommodated in the housing and unitized, the second movable core is seated between the second movable core and the suction member. A biasing member that biases in the direction is sandwiched.

  According to this, the second movable core, the urging member, and the suction member are accommodated in the housing and unitized, so that the axial movement amount of the second movable core and the urging load of the urging member are obtained at the unit stage. Assembling management is possible.

In the invention according to claim 12, the fuel injection valve according to claim 10 or claim 11 has a casing that houses the needle and the housing,
A needle and a unit are inserted and assembled in this order from the opening on the counter valve seat side of the casing toward the valve seat side.

  According to this, since the needle and the unit are inserted and assembled in this order from the opening on the opposite valve seat side of the casing toward the valve seat side, the shaft in one direction from one end of the fuel injection valve body such as the casing to the other end The direction can be assembled and productivity can be improved.

  Further, the invention according to claim 13 is characterized in that a valve body having a valve seat is assembled and fixed to the casing before the needle and the unit are inserted and assembled to the casing.

  Generally, when adjusting the amount of axial movement of the second movable core while directly assembling the second movable core and the suction member to a fuel injection valve body such as a casing, the amount of axial movement related to the second movable core is adjusted. If such a defect occurs, all the components on the fuel injector main body side may be regarded as defective.

  On the other hand, in the invention described in claim 13, since the axial movement amount of the second movable core is adjusted at the unit stage before being incorporated in the fuel injection valve, at least the valve is caused by a defect related to the second movable core. It is possible to prevent a fuel injection valve body such as a casing having a body from becoming defective.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments in which the fuel injection valve of the present invention is applied to an apparatus that injects and supplies fuel to a gasoline engine will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a partial cross-sectional view showing a configuration of a fuel injection device to which a fuel injection valve of an embodiment is applied. 2 is a diagram showing a unit composed of the suction member and the second movable core in FIG. 1, and FIG. 2 (a) is an exploded view of components of the unit such as a suction member, and FIG. 2 (b). ) Is a cross-sectional view showing the structure of the unit. FIG. 3 is a view showing an assembling process of one embodiment of the fuel injection valve in FIG. 1 and showing a process of assembling the valve body to the casing. FIG. 4 is a view showing an assembling process of one embodiment of the fuel injection valve in FIG. 1 and showing a process of inserting and assembling a needle and a unit into a casing. FIG. 5 is a diagram showing an assembly process of one embodiment of the fuel injection valve in FIG. 1, and an air gap between the second movable core in the unit and the first movable core cooperating with the needle. It is process drawing which shows the process of press-fitting a unit in a casing so that may become predetermined. FIG. 6 is a diagram showing an assembly process of the embodiment of the fuel injection valve in FIG. 1, and after the air gap between the second movable core and the first movable core becomes predetermined, the unit and It is process drawing which shows the process of welding a casing. FIG. 7 is a view showing an assembling process of one embodiment of the fuel injection valve in FIG. 1, and is a process diagram showing a process of assembling the drive coil to the casing. FIG. 8 is a diagram showing an assembly process of one embodiment of the fuel injection valve in FIG. 1, and an urging member and an urging force adjusting member for urging the first movable core on the fuel introduction part side of the casing. It is process drawing which shows the process of inserting and assembling. FIG. 9 is a diagram showing an assembly process of one embodiment of the fuel injection valve in FIG. 1, wherein the biasing force adjusting member is set so that the biasing force of the biasing member to the first movable core is predetermined. It is process drawing which shows the process press-fit in the fuel introduction part side of a casing. FIG. 10 is a view showing an assembly process of the embodiment of the fuel injection valve in FIG. 1, and is a process diagram showing a completed assembly state of the fuel injection valve.

  The fuel injection device 1 is used for an internal combustion engine (engine), particularly a gasoline engine. As shown in FIG. 1, the fuel injection device 1 includes a fuel injection valve 2 that injects fuel into a combustion chamber (not shown) of an engine, and control means (hereinafter referred to as an ECU) that controls an injection operation of the fuel injection valve 2. 100).

  More specifically, the fuel injection valve 2 is attached to an intake pipe or each cylinder such as an intake port of a multi-cylinder (for example, 4 cylinder) gasoline engine (hereinafter referred to as an engine), for example, and supplies fuel to a combustion chamber in the cylinder. Supply spray. In the present embodiment, it is assumed that the fuel injection valve 2 is provided in each cylinder. The fuel injection valve 2 is supplied with fuel pressurized by a fuel pump (not shown) through a fuel distribution pipe (not shown). In general, fuel in a fuel tank (not shown) is sucked and discharged to a fuel distribution pipe by a fuel pump (not shown), and the discharged fuel is guided. The discharged fuel is regulated to a predetermined pressure by a pressure regulating device such as a pressure regulator (not shown) and sent to the fuel distribution pipe. When the engine is a direct injection engine, the pressure of the fuel supplied to the combustion chamber is about 2 Mpa or higher, so that the fuel of a predetermined pressure (for example, 0.2 Mpa) sucked up from the fuel tank by the fuel pump is Pressurization is performed by a high-pressure pump (not shown), and the pressurized high-pressure fuel (for example, a predetermined fuel in the range of 2 to 13 MPa) is supplied to the fuel injection valve 2 via a fuel distribution pipe. The fuel discharged from the fuel pump and the fuel supplied from the high pressure pump to the fuel distribution pipe are regulated to a predetermined pressure by a pressure regulating device such as a pressure regulator (not shown). Hereinafter, the engine described in this embodiment is a gasoline direct injection engine.

  The fuel injection valve 2 has a substantially cylindrical shape, receives fuel from one end, and injects fuel from the other end via an internal fuel passage. The fuel injection valve 2 includes a valve portion B that blocks and allows fuel injection, and an electromagnetic drive portion S that drives the valve portion B, and fuel that flows into the internal fuel passage from the fuel introduction portion 48 side. From the valve part B to the engine cylinder.

  As shown in FIG. 1, the valve portion B includes a nozzle body 12 as a valve body, a needle 30 as a valve member, and a valve housing 16. The nozzle body 12 is fixed to the inner wall of the fuel injection side end of the valve housing 16 by welding. The nozzle body 12 has a conical surface 13 as an inner peripheral surface that decreases in diameter toward the nozzle hole 21 side in the fuel flow direction. The needle 30 can be separated from and seated on the conical surface 13.

  Here, the conical surface 13 constitutes a valve seat 14 on which the needle 30 can be separated and seated. Specifically, the contact portion 31 of the needle 30 is separated from and seated on the valve seat 14. The needle 30 is formed in a substantially shaft shape, and can reciprocate in the nozzle body 12 in the axial direction. Here, the valve seat 14 and the contact portion 31 constitute a seat portion that functions as an oil tight function for the valve portion to block fuel injection. Further, the nozzle body 12 and the valve housing 16 have a valve seat 14 and constitute a valve body from which the needle 30 is separated and seated. The nozzle body 12 and the valve housing 16 are not limited to being integrally formed by fixing different members by welding or the like, but may be integrally formed. The nozzle body 12 and the valve housing 16 are formed as separate members and are integrally formed, for example, when the nozzle body 12 is made of a specific material and the valve housing 16 is made of a material other than the specific material. preferable. As a result, a specific material having a relatively high wear resistance is used for the valve body 12 having the valve seat 14 on which the needle 30 is repeatedly seated and seated for each fuel injection, and the valve housing 16 is made of a material other than the specific material. Inexpensive materials can be used.

  As shown in FIG. 1, an injection hole 21 that can communicate with the internal fuel passage is disposed on the central side of the valve seat toward the downstream side of the fuel flow of the valve seat 14. The size of the nozzle hole 21, the direction of the nozzle hole axis, the nozzle hole arrangement, and the like are determined in accordance with the required fuel spray shape, direction, number, and the like. The opening area of the nozzle hole defines the flow rate when the valve is opened. The fuel injection amount of the fuel injection valve 2 is measured by the opening area of the opened nozzle hole, the lift amount of the needle 30 and the valve opening period. When the needle 30 is seated on the valve seat 14, fuel injection from the nozzle hole 21 is interrupted, and when the needle 30 is separated from the valve seat 14, fuel injection from the nozzle hole 21 is allowed and fuel is injected.

  It should be noted that the lift amount that affects the fuel injection amount described above increases as the lift amount increases in the lift-opening area relationship between the needle 30 (specifically, the contact portion 31 and the nozzle body 12 (specifically, the valve seat 14)). Since the separation distance between the seal portions 31 and 14 increases, the fuel injection amount increases while the opening area by the seal portion is smaller than the opening area by the injection hole (for example, a low lift state described later).

  As shown in FIG. 1, the electromagnetic drive unit S includes a cylindrical member 18, a first movable core 50, a second movable core 60 that faces the first movable core 50 in the axial direction, a housing 15, a coil 70, and a permanent magnet. 80 and urging members 59 and 69 as urging means for urging the first movable core 50 and the second movable core 60. Here, the 2nd movable core 60, the permanent magnet 80, and the housing 15 comprise the unit as described in a claim. A unit in which the second movable core 60, the permanent magnet 80, and the housing 15 are assembled into a unit is inserted into the cylindrical member 18. Moreover, the cylindrical member 18 comprises the casing as described in a claim. The cylindrical member 18 is a container that can accommodate the needle 30, the first movable core 50, the second movable core, the housing 15, and the permanent magnet 80 therein. Also called an injection valve body.

  The cylindrical member 18 is inserted into the inner peripheral wall of the valve housing 16 on the side opposite to the injection hole, and is fixed to the valve housing 16 by welding. Moreover, the cylindrical member 18 is comprised from the nozzle hole 21 side by the 1st magnetic cylinder part 18a, the nonmagnetic cylinder part 18b, and the 2nd magnetic cylinder part 18c. The nonmagnetic cylinder portion 18b prevents a magnetic short circuit between the first magnetic cylinder portion 18a and the second magnetic cylinder portion 18c. By preventing this magnetic short circuit, the magnetic flux generated by the electromagnetic force generated by energization of the coil 60 efficiently flows to the first movable core, the second movable core, and the permanent magnet 80. The cylindrical member 18 is formed by forming the first magnetic cylinder part 18a, the nonmagnetic cylinder part 18b, and the second magnetic cylinder part 18c from a pipe material made of a magnetic material, and heat-treating a part of the first magnetic cylinder part 18a, nonmagnetic cylinder part 18b, and second magnetic cylinder part 18c. 18b is formed. The tubular member 18 is not limited to being integrally formed, and may be formed by another member and integrally connected.

  The housing 15 is a substantially cylindrical body made of a non-magnetic material, and houses the second movable core 60 and the permanent magnet 80 therein as shown in FIGS. 1 and 2. Specifically, as shown in FIG. 2A, the housing 15 is formed of a pipe material or the like made of a nonmagnetic material, and has a step portion 15k made of stepped inner peripheries 15a and 15b. The step portion 15k restricts the movement of the second movable core 60 in the axial direction (specifically, the downward movement in the axial direction on the anti-permanent magnet 80 side). Here, the step portion 15k constitutes a locking portion described in the claims. More specifically, the inner circumferences 15a and 15b of the housing 15 are formed so that the inner circumference 15b is smaller than the inner circumference 15a. The inner periphery 15a holds the second movable core 60 so as to be movable. The inner periphery 15b is formed so that the lower end portion 60b of the second movable core 60 can be inserted, and the upper end portion 60a of the second movable core 60 is prevented from moving downward in the axial direction.

  In the present embodiment, the outer periphery of the housing 15 is preferably formed from stepped outer peripheries 15c and 15d. As a result, when the unitized housing 15 is inserted and assembled into the inner periphery of the cylindrical member 18 by press-fitting, the press-fitting load can be reduced, and the insertion and assembling by press-fitting becomes easy. Furthermore, it is preferable that the outer periphery 15d on the stepped portion 15k side (specifically, the lower side) of the stepped outer periphery 15c, 15d is formed smaller than the outer periphery 15c.

  The first movable core 50 is a stepped substantially cylindrical body made of a magnetic material such as magnetic stainless steel. The first movable core 50 is fixed to the needle 30, and the first movable core 50 and the needle 30 cooperate. The first movable core 50 is movable in the axial direction on the inner periphery of the cylindrical member 18. Note that the first movable core 50 and the needle 30 are not limited to those in which separate members are integrally formed by welding or the like as shown in FIG. 1, and may be formed integrally.

  As shown in FIG. 1, the second movable core 60 is a substantially cylindrical body made of a magnetic material such as magnetic stainless steel, and the second movable core 60 can move in the cylindrical member 18 in the axial direction. Specifically, as shown in FIGS. 1 and 2, the second movable core 60 is configured as a unit and is movable in the axial direction in the housing 15 inserted and fixed to the cylindrical member 18. As shown in FIG. 2A, the second movable core 60 has a stepped outer peripheral shape, and the outer periphery on the upper end portion 60a side of the second movable core 60 is larger than the inner periphery on the lower end portion 60b side. Is formed. The upper end portion 60 a, that is, the second movable core 60 is configured such that the axial position of the second movable core 60 on the side away from the permanent magnet 80 is regulated by the step portion 15 k of the housing 15. The lower end portion 60b can be inserted through the inner circumferences 15a and 15b of the housing 15. As shown in FIGS. 1 and 2, in a state where the downward movement of the second movable core 60 in the axial direction is restricted by the step portion 15 k, the lower end portion 60 b extends from the lower end surface of the housing 15 to the first movable core 50 side. Protruding.

  In the present embodiment, the inner periphery of the second movable core 60 is preferably formed from stepped inner peripheries 60c and 60d. Specifically, the inner circumference 60d is formed smaller than the inner circumference 60d. The second movable core 60 allows the biasing member 59 to be inserted, holds the biasing member 69 at a step between the inner periphery 60d and the inner periphery 60d, and receives the biasing force of the biasing member 69.

  The permanent magnet 80 is a magnetized magnetic material such as a ferrite magnet, a rare earth magnet, or an alnico magnet. As shown in FIG. 1, the permanent magnet 80 is formed in a substantially cylindrical body and is magnetized so as to generate a predetermined magnetic force. The permanent magnet 80 is disposed on the side of the second movable core 60 opposite to the first movable core 50 so as to face the second movable core 60 in the axial direction.

  In this embodiment, the permanent magnet 80 is disposed on a magnetic pole having the end surface on the second movable core 60 side as the S pole and the end surface on the anti-second movable core 60 side as the N pole. The magnetic pole arrangement of the permanent magnet 80 is not limited to the end surface on the second movable core 60 side being the S pole and the end surface on the anti-second movable core 60 side being the N pole, but the end surface on the second movable core 60 side is not limited. A magnetic pole arrangement in which the N pole and the end surface on the side opposite to the second movable core 60 are S poles may be used. The end face on the second movable core 60 side is the N pole, and the end face on the second movable core 60 side is the N pole instead of the former where the end face on the second movable core 60 side is the S pole and the end face on the anti-second movable core 60 side is the N pole. 2 In the latter configuration in which the magnetic pole is disposed with the end surface on the movable core 60 side as the S pole, the ECU 100 in the latter is used so that the relationship between the magnetic force by the permanent magnet 80 and the electromagnetic force by the drive coil is the same as the former. The energization direction to the drive coil is reversed.

  In the present embodiment, it is preferable to provide the magnetic body 17 between the second movable core 60 and the permanent magnet 80 as shown in FIGS. The magnetic body 17 is not magnetized by magnetization unlike a ferromagnetic material such as a permanent magnet, but uses a magnetic material such as a soft magnetic material that is relatively easily magnetized and has little residual magnetism. For example, depending on the energization direction to the drive coil, the magnetic field generated in the first movable core 50 and the second movable core 60 (magnetic pole direction of the magnetic force) and the magnetic field of the permanent magnet 80 may be opposite to each other. In this case, by providing the magnetic body 17, the flow of magnetic flux of the drive coil does not directly act on the permanent magnet 80 itself that becomes a magnetic resistance against the flow of the magnetic flux, and the permanent magnet 80 and the second movable core 60. Acting on the magnetic body 17 provided between the two. Therefore, since the influence of the magnetic flux of the permanent magnet 80 can be reduced or eliminated, the electromagnetic force generated in the drive coil can be used efficiently.

  Here, the permanent magnet 80 and the magnetic body 17 constitute a magnetized member as claimed. Furthermore, the magnetizing member having the permanent magnet 80 constitutes an attracting member capable of attracting the second movable core 60 to the side opposite to the first movable core 50 according to the direction of the magnetic field of the drive coil (direction of magnetic force). The permanent magnet 80 and the magnetic body 17 are not limited to the magnetizing member, and the permanent magnet 17 may constitute the magnetizing member. Here, the lower end portion of the magnetizing member has a function of regulating the amount of movement of the second movable core 60 in the direction opposite to the first movable core 50 (in the axial direction in FIG. 1). More specifically, in this embodiment, the magnetic body 17 regulates the amount of movement of the second movable core 60 in the direction toward the permanent magnet 80 (in the axial direction in FIG. 1).

  Further, as shown in FIGS. 1 and 2, the magnetic body 17 is formed in a bottomed cylindrical shape so as to receive and hold the permanent magnet 80, and can be inserted and fixed to the inner periphery 15 a of the housing 15. is there. In this embodiment, as a method of inserting and fixing the magnetic body 17 and the housing 15, the outer periphery of the magnetic body 17 is inserted and assembled by press-fitting into the inner periphery 15a of the housing 15, and the magnetic body 17 and the housing 15 are press-fitted. Fixed. The magnetic body 17 and the permanent magnet are formed so that the biasing member 59 can be inserted therethrough.

  Here, the amount of axial movement L2 of the second movable core 60 is the same as that of the lower end surface of the magnetic body 17 in the state where the second movable core 60 is regulated by the step portion 15k as shown in FIG. It is determined by the air gap formed between the upper ends of the two movable cores 60. Further, as shown in FIG. 1, the axial movement amount L <b> 1 is equal to the lower end portion of the second movable core 60 and the upper end portion of the second movable core 50 in a state where the second movable core 60 is regulated by the step portion 15 k. Is determined by the air gap formed between the two. The axial movement amount L1 is the axial movement amount of the first movable core 50 described in the claims. In the axial direction of the first movable core 50 when the lift amount of the needle 30 is in the low lift state. This is the maximum amount of movement that can be moved. Note that the maximum amount of movement of the first movable core 50 that can move in the axial direction when the lift amount of the needle 30 is in a high lift state is defined by L1 + L2. In the low lift state, the second movable core 60 is locked to the step portion 15k, and the movement of the second movable core 60 toward the valve seat 14 is restricted. In the high lift state, the second movable core 60 contacts the lower end portion (specifically, the lower end surface of the magnetic body 17) of the magnetizing member (specifically, the permanent magnet 80 and the magnetic body 17), and the second movable core 60 moves toward the counter valve seat 14 direction side. The movement of the movable core 60 is restricted.

  The coil 70 is wound around the outer periphery of the resin spool 71 in a predetermined direction. The ends of the coil 70 are drawn out as two terminals 75. The terminal 75 supplies a current from an external power source or the like (specifically, the ECU 100) to the coil 70. The spool 71 is attached to the outer periphery of the cylindrical member 18. Here, the coil 70, the spool 71, and the terminal 75 constitute a drive coil. A resin mold 19 is formed on the outer peripheral side of the drive coil such as the coil 70, and a connector portion 74 that accommodates the terminal 75 is provided by the resin mold 19.

  As shown in FIG. 1, the urging members 59 and 69 include a first urging member 59 that urges the first movable core 50 in the seating direction of the needle 30, and a second movable core 60 in the seating direction of the needle 30. It comprises a second urging member that urges. The first urging member 59 and the second urging member 69 may be any members as long as they are elastic bodies such as spring members that are displaced according to the applied load. In the present embodiment described below, a spring member such as a compression spring is used.

  The first biasing member 59 is locked to the first movable core at one end, and locked to a biasing force adjusting member (hereinafter referred to as an adjusting pipe) 41 at the other end. Specifically, the adjusting pipe 41 is press-fitted into the inner periphery 48a of the fuel introduction portion 48 to form a fuel passage therein. By adjusting the amount of press-fitting of the adjusting pipe 41, the urging force (load) of the first urging member 59 that urges the first movable core 50 is changed. The first movable core 50 and the needle 30 are biased toward the valve seat 14 by the biasing force of the first biasing member 59.

  The second urging member 69 is sandwiched between the second movable core 60 and a magnetizing member facing the second movable core 60 such as the magnetic body 17 in the axial direction at the other end. As shown in FIG. 1, a first urging member 59 and an adjusting pipe 41 are disposed on the inner peripheral side of the second urging member 69. The second urging member 69 and the first urging member 59 constitute urging means that are arranged in a double manner inside and outside.

  In the present embodiment, the adjusting pipe 41 is preferably a substantially cylindrical body, and the contact surface of the adjusting pipe 41 with the first urging member 59 is preferably cylindrical. As a result, the second urging member 69 and the first urging member 59 are doubly arranged inside and outside so that the respective urging forces to the first movable core 50 and the second movable core 60 can be independently adjusted. The adjusting pipe 41 can be disposed.

  As shown in FIG. 1, the internal fuel passage of the fuel injection valve 2 includes an inner periphery of the fuel introduction part 48, an inner periphery of the adjusting pipe 41, and a permanent magnet from upstream to downstream of the fuel flow. 80, the inner periphery 17a of the magnetic body 17, the inner periphery 60c, 60d of the second movable core 60, the radial passage 52 of the first movable core 50, the inner periphery of the tubular member 40, the valve The inner periphery of the housing 16 and the fuel passage formed by the inner periphery of the nozzle body 12 and the needle 30 are configured in this order, and these constitute an internal fuel passage as a fuel flow path toward the injection hole 21. is doing.

  The ECU 100 is configured as a microcomputer having a known configuration in which a read only memory (ROM), a random access memory (RAM), a microprocessor (CPU), an input port, and an output port (not shown) are connected to each other via a bidirectional bus. Yes. The ECU 100 controls the energization period of the fuel injection valve 2 by starting and stopping energization of the coil 70 of the fuel injection valve 2 using a power source such as a battery. Fuel injection valves are read in accordance with various engine programs (not shown) by reading signals from various sensors (not shown) that detect engine operating conditions such as engine speed, intake pipe pressure (or intake air amount), and coolant temperature. The operation of the second electromagnetic drive unit S is controlled (see FIG. 1).

  The electrical configuration of the fuel injection device 1 of the present embodiment will be described with reference to FIG. The ECU 100 supplies current in a predetermined direction to the two terminals 75 of the fuel injection valve 2 based on signals from various sensors that detect the operating state of the engine. ECU 100 includes a control unit main body (not shown) and an energization direction switching circuit (not shown) arranged in or on the control unit main body. Since the control unit is the microcomputer described above, description thereof is omitted.

  The energization direction switching circuit has a configuration in which a so-called H-bridge circuit including four switching elements (hereinafter referred to as transistors) TR1, TR2, TR3, and TR4 is assembled with the coil 70 as a center. More specifically, one end side of the coil 70 wound in a predetermined direction is connected to an intermediate point between the first transistor TR1 on the battery power supply voltage Vb side and the second transistor TR1 on the ground side, which are connected in series. Has been. The other end side of the coil 70 is connected in series to an intermediate point between the third transistor TR3 on the battery power supply voltage Vb side and the fourth transistor TR4 on the ground side. In this energization direction switching circuit, only the energization of the base terminal of the first transistor TR1 and the base terminal of the fourth transistor TR4 is turned on, so that the direction of the current flowing through the coil 70 becomes a predetermined direction. Further, by turning ON only the power supply to the base terminal of the second transistor TR2 and the base terminal of the third transistor TR3, the direction of the current flowing through the coil 70 is reversed from the predetermined direction and becomes the anti-predetermined direction. . In the following description of the present embodiment, the predetermined current direction is referred to as a forward direction, and the anti-predetermined current direction is referred to as a reverse direction.

  Here, the ECU 100 has switching means for switching the energization direction to the drive coil of the fuel injection valve 2 as one of means for controlling the system. This switching means switches the direction of current flowing through the coil 70 from the normal direction to the reverse direction, or from the reverse direction to the normal direction by switching the energization direction.

  The operation of the fuel injection device 1 having the above-described configuration, particularly the operation of the fuel injection valve 2 will be described.

  (1) When the drive coil (specifically, the coil 70) is in a non-energized state, the magnetic flux of the permanent magnet 80 forms a closed circuit through the magnetic body 17. Since the magnetic force of the permanent magnet 80 does not reach the second movable core 60 through the magnetic body 17, no attractive force that attracts the second movable core 60 to the permanent magnet 80 is generated. On the other hand, since the drive coil is in a non-energized state, no electromagnetic force is generated in the coil 70, and the needle 30 is pressed against the valve seat 14 by the first biasing member 59. As a result, the fuel injection valve 2 is closed and fuel is not injected from the injection hole 21.

  Since the second movable core 60 is biased toward the step portion 15k of the housing 15 by the biasing force of the second biasing member 69, the second movable core 60 is locked to the step portion 15k by this biasing force. Has been. For this reason, the movement position of the second movable core 60 is restricted to the lower limit position of the axial movement (hereinafter referred to as the low lift state restriction position).

  (2) When the energization direction of the drive coil is in the positive direction, the coil 70 is energized and an electromagnetic force is generated in the coil 70. Further, since the energization direction to the drive coil is set to the positive direction, the magnetic pole (for example, S pole in this example) of the second movable core 60 on the permanent magnet 80 side and the second movable core 60 of the permanent magnet 80 are set. The magnetic poles on the side end faces (for example, the S pole in this example) are repelled. As a result, the 2nd movable core 60 is latched by the level | step-difference part 15k, and is maintained in the position restrict | limited to a low lift state.

  On the other hand, the second movable core 60 magnetized by the coil 70 attracts the first movable core 50, and the needle 30 cooperating with the first movable core 50 is separated from the valve seat 14. At this time, since the axial displacement of the first movable core 50 is restricted by the second movable core 60 in the low lift state restriction position, the lift amount H of the needle 30 is restricted to the low lift state (H = HD1). ).

  At this time, the electromagnetic force of the coil 70 repelling against the magnetic force (hereinafter referred to as steady magnetic force) by the permanent magnet 80 is acting on the second movable core 60. The electromagnetic force of the coil 70, that is, the flow of magnetic flux, does not act directly on the permanent magnet 80 itself, but acts on the magnetic body 17. As a result, the flow of magnetic flux in the coil 70 is not hindered by the flow of magnetic flux in the permanent magnet 80 that becomes a magnetic resistance to the flow of magnetic flux. Therefore, compared with a fuel injection valve having a configuration in which the permanent magnet 80 and the second movable core 60 are directly opposed in the axial direction without disposing the magnetic body 17 between the permanent magnet 80 and the second movable core 60, the coil Even when the electromagnetic force generated in 70 is reduced to about half, it is possible to obtain an operating force equal to or higher than that.

  Here, the magnetic circuit formed by the magnetic force of the permanent magnet 80 and the magnetic circuit formed by the electromagnetic force of the coil 70 are respectively transmitted through the magnetic body 17 sandwiched between the permanent magnet 80 and the second movable core 60. A closed circuit is formed.

  (3) In the state where the energization direction to the drive coil is in the reverse direction, the energization direction to the drive coil can be switched from the normal direction to the reverse direction, so the direction of the magnetic field due to the electromagnetic force generated in the coil 70 is the permanent magnet 80. The direction of the magnetic field is the same. At this time, a magnetic force biased by the electromagnetic force of the coil 70 acts on the second movable core 60 in addition to the steady magnetic force of the permanent magnet 80. As a result, the second movable core 60 is attracted to the magnetic body 17 side and locked to the lower end surface of the magnetic body 17. As a result, the movement position of the second movable core 60 is restricted to the upper limit position of the axial movement (hereinafter referred to as a high lift state restriction position).

  On the other hand, the second movable core 60 magnetized by the coil 70 and the permanent magnet 80 attracts the first movable core 50 to bring the lift amount H of the needle 30 into a high lift state (H = HD2, where HD2> HD1). .

  Next, the overall operation of the fuel injection device 1 will be described. ECU 100 detects the operating state of the engine from signals from various sensors. Then, the ECU 100 determines the injection / spray characteristics such as the injection rate and the spray shape for fuel injection from the injection hole 21 suitable for the operating state based on the detected operating state of the engine. When the ECU 100 determines that the injection / spray characteristic suitable for the operating state is that the lift amount of the needle 30 is set to the low lift state, the ECU 100 determines the first and fourth transistors TR1 of the energization direction switching circuit. , TR4 is turned on, and the energization direction to the drive coil is set to the positive direction. As a result, the movement position of the second movable core 60 is restricted to the low lift state restriction position, and the lift amount H of the needle 30 is controlled to H = HD1. On the other hand, when the ECU 100 determines that the injection / spray characteristics suitable for the operating state are those that make the lift amount of the needle 30 a high lift state, the ECU 100 determines the second and third of the energization direction switching circuit. The transistors TR2 and TR3 are turned on, and the energization direction to the drive coil is reversed. As a result, the movement position of the second movable core 60 is restricted to the high lift state restriction position, and the lift amount H is controlled to H = HD2.

  Note that, by changing the lift amount, for example, the opening area for fuel injection changes, so the injection amount per unit time can be changed. As a result, the injection amount injected from the fuel injection valve 2 is adjusted by adjusting the energization period to the coil 70. Furthermore, even if the energization period to the coil 70 is the same, the injection amount can be changed by setting the lift amount H to either H = HD1 or H = HD2.

  In this manner, the polarity (magnetic pole) of the second movable core 60 can be reversed by switching the energization direction to the drive coil by the ECU 100. When the polarity of the second movable core 60 is reversed, either the stationary magnetic force of the permanent magnet 80 and the magnetic force biased by the electromagnetic force of the coil 70 or the electromagnetic force of the coil 70 repelling the stationary magnetic force of the permanent magnet 80 is the second. It acts on the movable core 60. When a biased magnetic force acts on the second movable core 60, the second movable core 60 is attracted to the permanent magnet 80, and is restricted to an upper limit position (high lift state limit position) that can move upward in the axial direction of the second movable core 60. . On the other hand, when the electromagnetic force of the coil 70 repelling the permanent magnet 80 acts on the second movable core 60, the second movable core 60 is pressed toward the anti-permanent magnet 80, that is, in the direction of the valve seat 14, and the second movable core. 60 is restricted to a lower limit position (low lift state restriction position) that can move downward in the axial direction. Note that the electromagnetic force of the drive coil can act on the first movable core 50 and the second movable core 60, and the electromagnetic force is generated in the coil 70 in either the low lift state or the high lift state. ing. The first movable core 50 is attracted by this electromagnetic force.

  Here, the second movable core 60, the magnetized member composed of the permanent magnet 80 and the magnetic body 17, and the ECU 90 (specifically, the energization direction switching circuit) constitute lift variable means for varying the lift amount of the needle 30. . Due to the displacement operation of the second movable core 60 (specifically, the position moving in the axial direction), the displacement amount (movement amount moving in the axial direction) of the first movable core 50, that is, the lift amount H of the needle 30 is changed from HD2 to HD1. Alternatively, it can be changed from HD1 to HD2. The lift variable means switches the lift amount of the fuel injection valve 2 between a low lift state (H = HD1) and a high lift state (H = HD2).

  A method for assembling the fuel injection valve 2 in the fuel injection device 1 will be described with reference to FIGS.

  First, when the fuel injection valve 2 having the above-described configuration is represented by each component unit for assembly, the fuel injection valve 2 includes the unit shown in FIG. 2B and the second shown in the development view of FIG. And a holder subassembly as a unit. The holder subassembly includes a nozzle body 12, a valve housing 16, and a tubular member 18. Note that the holder subassembly is not limited to the one composed of the nozzle body 12, the valve housing 16, and the cylindrical member 18, but may include the nozzle body 12, the valve housing 16, the cylindrical member 18, and the drive coil. Well, before assembling the unit (see FIG. 2 (b)), an assembly structure in which constituent members including the cylindrical member 18 other than the unit, which constitute the fuel injection valve 2 other than the unit, are assembled ( Hereinafter, it may be referred to as a fuel injection valve body).

  In addition, the holder assembly demonstrated below shall be comprised from the nozzle body 12, the valve housing 16, and a cylindrical member.

  As shown in FIG. 2A, the second movable core 60, the second urging member 69, and the magnetizing members 17 and 80 are sequentially transferred to the housing 15 in the axially downward direction (hereinafter referred to as the axial direction) in FIG. The unit shown in FIG. 2B is assembled. At this time, the amount of insertion for inserting the magnetized members 17 and 80 into the housing 15 by press-fitting is the amount of axial movement when the second movable core 60 is locked to the step portion 15k so as to be in the low lift limit position. The press-fitting management is performed so as to be L2. Thus, the axial movement amount L2 of the second core 60 is determined by the press-fitting amount of the magnetizing members 17 and 80 into the housing 15. When the magnetic member is press-fitted into the housing 15, the permanent magnet 80 is accommodated in the magnetic body 17, and not only the magnetic body 17 is press-fitted into the housing 15, but only the magnetic body 17 is press-fitted into the housing 15, You may insert in the magnetic body 17 so that a permanent magnet may be accommodated.

  In addition, after the magnetizing members 17 and 80 are press-fitted into the housing 15 and the press-fitting amount is managed and determined so as to be the axial movement amount L2, the magnetizing members 17 and 80 (in detail, as shown in FIG. 2B) The magnetic body 17) and the housing 15 are preferably joined by welding J. Thereby, the axial movement amount L2 of the second movable core 60 can be reliably maintained in any state of the unit stage, the subsequent stroke, and the completed state of the fuel injection valve 2.

  As shown in FIG. 3, the nozzle body 12, the valve housing 16, and the cylindrical member 18 are assembled to form a holder assembly. For example, as shown in FIG. 3, the nozzle body 12 and the cylindrical member 18 are inserted into the valve housing 16 in the axial direction in this order, and the holder assembly is assembled. The step of assembling the unit (see FIG. 2) and the step of assembling the holder assembly (see FIG. 3) are not limited to the order of the steps of assembling the unit and then assembling the holder assembly. May be in the order of the processes.

  As shown in FIG. 4, in order to insert and assemble the first movable core 50 and the unit into the holder assembly, the first movable core 50 and the unit are sequentially axially attached to the holder assembly (specifically, the cylindrical member 18). Insert into. More specifically, the first movable core 50 is fixed to the needle 30 by welding or the like in a separate process in advance, and is assembled integrally. In the holder assembly, the first movable core 50 and the unit are inserted in the axial direction from the opening on the side opposite to the valve seat 14 of the cylindrical member 18 toward the opening on the valve seat 14 side. In this step, the nozzle body 12, the valve housing 16, and the cylindrical member 18 constituting the holder assembly are fixed by welding J or the like in order to assemble the first movable core 50, that is, the initial position of the needle 30. The initial positions of the needle 30 and the first movable core 50 are states in which the needle 30 is seated on the valve seat 14 of the nozzle body 12.

  As shown in FIGS. 5 and 6, after the needle 30 and the first movable core 50 are inserted and assembled in the initial position state in the holder assembly, the unit moves so as to have the axial movement amount L1 shown in FIG. Is press-fitted into the inner periphery of the cylindrical member 18. Thus, the axial movement amount L1 of the first working core 50 in the low lift state is determined by the press-fitting amount of the unit into the cylindrical member 18 (see FIG. 6).

  At this time, since the amount of axial movement L2 of the second movable core 60 is adjusted in the unit, the unit is inserted into the cylindrical member 18, and the lower end portion of the unit, that is, the lower end surface of the second movable core 60, By adjusting only the air gap with the upper end surface of the first movable core 50, the axial movement amount L1 and the axial movement amount L2, that is, the lift amount of the needle 30 can be adjusted. As a result, the second movable core 60 and the magnetized members 17 and 80 are accommodated in the housing 15 to form a unit, so that the process of assembling the fuel injection valve 2 by assembling the unit with other components is one conventional movable core. The procedure can be almost the same as the assembly process of the fuel injection valve.

  After the adjustment of the lift amount of the needle 30 is completed in the step shown in FIG. 6, the drive coil (coil 70 and the like) and the fuel introduction part 48 are inserted and assembled into the cylindrical member 18 as shown in FIG. 7.

  After the unit is press-fitted into the cylindrical member 18 and the press-fitting amount is managed and determined so as to be the axial movement amount L1, the unit (specifically, the housing 15) and the cylindrical member 18 are connected as shown in FIG. It is preferable to join by welding J. Accordingly, the axial movement amount L1 of the second movable core 50 is reliably maintained regardless of the stage of the fuel injection valve body shown in FIG. 6 and the subsequent stroke or the completed state of the fuel injection valve 2. Therefore, the lift amount of the needle 30 can be switched between a low lift state and a high lift state, and HD1 and DH2 corresponding to these lift states can be reliably maintained.

  In FIG. 7, after the drive coil is attached to the outer periphery of the cylindrical member 18 and the fuel introduction part 48 is attached to the inner periphery, as shown in FIGS. The member 59 and the adjusting pipe 41 are inserted and assembled in order, and the adjusting pipe 41 is press-fitted so that the biasing force of the first biasing member 59 to the first movable core becomes a predetermined load.

  As shown in FIG. 10, an oil ring supplied to the fuel injection valve 2, an O-ring 91 for removing foreign matter in the fuel, and a filter 98 are assembled to the fuel introduction portion 48. 2 assembly is completed.

  Next, the operational effects of the present embodiment will be described. (1) The amount of movement of the first movable core in the axial direction at the position of the second movable core on the suction member side in the two movable cores 50 and 60. In the fuel injection valve 2 in which the lift amount of the needle 30 is varied by regulating the above, the fuel injection valve main body such as the cylindrical member 18 that can move the first movable core 50 and the second movable core 60 in the axial direction is separated. The housing 15 can be inserted into and fixed to the fuel injection valve body, and the second movable core 60 and the magnetized members 17 and 80 are accommodated in the housing 15 and unitized. Thus, the axial movement amount L2 of the second movable core 60 defined by the air gap between the second movable core 60 and the magnetized member is moved in a predetermined axial direction at the unit stage before being incorporated into the fuel injection valve body. The amount can be adjusted to L2. Therefore, since it can be adjusted to the predetermined amount of movement L2 in the unit stage before being incorporated into the fuel injection valve body, it is not necessary to prepare a large number of parts for selective assembly.

  When adjusting the axial movement amount L2 of the second movable core 60 while directly assembling the second movable core 60 and the magnetized members 17 and 80 to the fuel injection valve body, the optimal axial movement amount is obtained. In doing so, there is a possibility that the attachment and detachment of the magnetized members 17 and 80 to and from the fuel injection valve 2 is repeated. In this case, for example, the cleanliness inside the fuel injection valve 2 may be impaired, and the time required for assembly of the fuel injection valve 2 may be relatively long.

  On the other hand, in the fuel injection valve 2 having the above-described configuration, the axial movement amount L2 of the second movable core 60 can be managed by the unit. Therefore, it is not necessary to attach or detach, and the assembly time of the fuel injection valve 2 can be reduced.

  Therefore, in the case of having two movable cores 50 and 60 and having the function of making the lift amount of the needle 30 variable by regulating the axial movement amount of the other movable core 50 with one movable core 60. Can improve the performance.

  (2) In the present embodiment, axial movement of the second movable core 60 (specifically, movement of the magnetized members 17 and 80 on the anti-permanent magnet 80 side) is restricted to the inner peripheries 15a and 15b of the housing 15. It has a stepped portion 15k and is configured to press-fit the magnetized members 17 and 80 into the inner circumferences 15a and 15b. According to this, the axial movement amount L2 of the second movable core 60 can be determined by press-fitting the magnetized members 17 and 80 into the housing 15.

  (3) Furthermore, in this embodiment, the unit is configured to be press-fitted into the cylindrical member 18. According to this, the cylindrical member 18 accommodates the first movable core, the second movable core, and the suction member, and is capable of moving the first movable core and the second movable core in the axial direction. 18. That is, the unit is press-fitted into the fuel injection valve body. Thus, the lift amount of the needle 30 can be adjusted by press-fitting a unit in which the axial movement amount L2 of the second movable core 60 is adjusted in advance into the fuel injection valve body.

  (4) Furthermore, in the present embodiment, the second movable core 60 is provided with a second biasing member 69 that biases the second movable core 60 in the seating direction of the needle 30, and the second biasing member 69 is the second movable core. 60 and the magnetizing members 17 and 80 (specifically, the magnetic body 17 on the lower end side of the magnetizing members 17 and 80). Thus, the second movable core 60, the second urging member 69, and the magnetizing members 17 and 80 are accommodated in the housing 15 and unitized, so that the axial movement amount of the second movable core 60 in the unit stage. The assembly management of the urging load on the second movable core 60 of L2 and the second urging member 60 is possible.

  (5) Furthermore, in the present embodiment, the magnetizing members 17 and 80 are permanent capable of attracting the second movable core 60 to the anti-first movable core 50 side according to the direction of the magnetic force of the drive coil (direction of the magnetic field). A magnet 80 is included.

  For example, when it is desired to switch the axial position of the second movable core 60 and switch the lift amount of the needle 30 between the low lift state and the high lift state, as a method of driving the second movable core 60, for example, supplying a current to the magnetization member When a driving member such as a coil that generates magnetic force is used, in addition to the power consumption for driving the driving coil, the power consumption for driving the driving member is required.

  On the other hand, in this embodiment, since the magnetized members 17 and 80 having the permanent magnet 80 capable of attracting the second movable core 60 to the anti-first movable core 50 side according to the direction of the magnetic force of the drive coil are used, the drive It is not necessary to use a driving member that generates magnetic force by supplying current separately from the coil, and the power consumption of the entire system (specifically, the fuel injection device 1 having the fuel injection valve 2) including the fuel injection valve 2 that switches the lift amount of the needle 30. The amount can be reduced.

  (6) Furthermore, in this embodiment, it is preferable that the magnetized members 17 and 80 include the permanent magnet 80 and the magnetic body 17 that can accommodate the permanent magnet 80 therein. According to this, the magnetic body 17 is disposed between the second movable core 60 and the permanent magnet 80. As a result, for example, when the magnetic field (direction of magnetic force) generated in the first movable core 50 and the second movable core 60 by energization of the drive coil is opposite to the magnetic field of the permanent magnet 80, the magnetic flux of the drive coil The flow does not directly act on the permanent magnet 80 itself that becomes a magnetic resistance against the flow of the magnetic flux, but acts on the magnetic body 17 provided between the permanent magnet 80 and the second movable core 60. Can alleviate or eliminate the influence of magnetic flux. Therefore, the electromagnetic force generated in the drive coil can be used efficiently.

  Further, as a method for managing the amount of insertion of the magnetized members 17 and 80 into the unit, the magnetic body 17 is inserted after only the magnetic body 17 is inserted into the housing 15 and the insertion amount (press-fit amount in this embodiment) is determined. The permanent magnet 80 can be assembled inside, or the magnetic body 17 can be assembled into the housing 15 in a state where the permanent magnet 80 is assembled inside the magnetic body 17.

(7) The method of assembling the fuel injection valve 2 having the configuration described above is as follows:
The needle 30 that is separated from and seated on the valve seat 14, the two movable cores 50 and 60, the magnetizing members 17 and 80, and the cylindrical member 18 that accommodates these members, of the two movable cores 50 and 60 The lift which is used for the fuel injection valve 2 which makes the movement amount of the first movable core 50 variable according to the axial position of the second movable core 60 on the magnetizing members 17, 80 side and is separated from the valve seat 14 of the needle 30. In the fuel injection valve assembling method for adjusting the axial movement amount L2 of the second movable core 60 so that the amount is variable,
Forming a housing 15 for accommodating the second movable core 60 and the magnetized members 17, 80;
The housing 15 accommodates the second movable core 60 and the magnetized members 17 and 80 into a unit,
The axial movement amount L <b> 2 of the second movable core 60 is configured to be adjusted by the press-fit amount for press-fitting the magnetized members 17 and 80 into the housing 15.

  According to this, as an assembling method for adjusting the axial movement amount L <b> 2 of the second movable core 60, the housing 15 that accommodates the second movable core 60 and the magnetized members 17, 80 is formed, and the second movable core 60 is formed thereon. The magnetized members 17 and 80 are accommodated as a unit, and the axial movement amount L2 of the second movable core 60 can be adjusted by the press-fitting amount of the magnetized members 17 and 80 into the housing 15 at this unit stage. Therefore, the axial movement amount L2 of the second movable core 60 can be adjusted at the unit stage before being incorporated into the fuel injection valve 2, and productivity can be improved.

  (8) In the assembling method of the present embodiment, when the second movable core 60 and the magnetized members 17 and 80 are accommodated in the housing 15 and unitized, the second movable core 60 and the magnetized members 17 and 80 The second urging member 60 that urges the second movable core 60 in the seating direction of the needle 30 is sandwiched therebetween. According to this, the second movable core 50, the second urging member 69, and the magnetizing members 17, 80 are accommodated in the housing 15 and unitized, whereby the axial movement amount L2 of the second movable core 60 and the second Assembling management of the urging load of the second urging member 69 to the two movable cores can be performed.

  (9) Furthermore, in the assembling method of the present embodiment, the combination of the needle 30 and the first movable core 50 from the opening on the valve seat 14 side of the tubular member 18 toward the opening on the valve seat 14 side. The attachment structure and the unit are inserted and assembled in this order. According to this, the assembly structure such as the needle 30 and the unit are inserted and assembled in order in one direction from the opening on the valve seat 14 side to the opening on the valve seat 14 side of the cylindrical member 18. Therefore, the cylindrical member 18, that is, the fuel injection valve main body, can be assembled in the axial direction from one end to the other end, so that productivity can be improved.

  (10) Furthermore, in the assembling method of the present embodiment, the assembling structure such as the needle 30 and the valve having the valve seat 14 on the tubular member 18 before the unit is inserted and assembled to the tubular member 18. The nozzle body 12 and the valve housing 16 as the body are assembled and fixed.

  In general, when adjusting the axial movement L2 of the second movable core 60 while directly assembling the second movable core 60 and the magnetized members 17 and 80 to the cylindrical member 18, that is, the fuel injection valve body, If a defect such as the axial movement amount L2 related to the movable core 60 occurs, all components on the fuel injection valve main body side may be regarded as defective.

  On the other hand, in the assembling method of the present embodiment, the amount of axial movement of the second movable core 60 is adjusted at the unit stage before being incorporated in the fuel injection valve 2. Further, it is possible to prevent the components on the fuel injection valve main body side including at least the nozzle body 12, the valve housing 16, and the cylindrical member 18 from becoming defective.

(Second Embodiment)
A second embodiment will be described with reference to FIG. In the following description, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and description thereof will not be repeated. FIG. 11 is a cross-sectional view showing a cylindrical member constituting the casing of the fuel injection valve according to the present embodiment.

  In the second embodiment, in the cylindrical member 18 described in the first embodiment, instead of being integrally formed, as shown in FIG. 11, a cylinder formed from another member and connected integrally. The shape member 118 is used. As shown in FIG. 11, the cylindrical member 118 includes a first magnetic cylinder part 18a and a second magnetic cylinder part 18c made of a pipe material made of a magnetic material, and a non-magnetic cylinder part 18b made of a pipe material made of a non-magnetic material. Are formed separately. The first magnetic cylinder part 18a, the second magnetic cylinder part 18c, and the nonmagnetic cylinder part 18b are welded in the order of the first magnetic cylinder part 18a, the nonmagnetic cylinder part 18b, and the second magnetic cylinder part 18c by welding J or the like. Connected.

  Even if comprised in this way, the effect similar to 1st Embodiment can be acquired.

(Third embodiment)
In the third embodiment, in the second urging member 69 described in the first embodiment, the second urging member 69 is replaced with a member sandwiched between the second movable core 60 and the magnetizing members 17 and 80. As shown in FIG. 12, it is assumed that the magnetized members 117 and 180 can be inserted. FIG. 12 is a partial cross-sectional view showing the configuration of a fuel injection device to which the fuel injection valve of this embodiment is applied.

  As shown in FIG. 12, the second urging magnetic members 117 and 180 are provided with a second inner periphery 180a of the permanent magnet 180 and an inner periphery 117a of the magnetic body 117 so that the second urging member 169 can be inserted. The urging member 169 is formed larger than the outer diameter. The second urging member 69 is configured to be sandwiched between the second movable core 60 and the fuel introduction part 48.

  Even if comprised in this way, the effect similar to 1st Embodiment can be acquired.

  Furthermore, since the magnetizing members 117 and 80 can be inserted into the second urging member 169, after the unit in which the axial movement amount L2 of the second movable core 60 is adjusted in advance is inserted and fixed in the fuel injection valve body, the unit The second urging member 69 can be inserted into the unit so as to give a predetermined urging force to the second movable core 60 therein.

(Fourth embodiment)
In the third embodiment, in the second movable core 60 described in the first embodiment, the second biasing member 69 is replaced with a second biasing member 69 as shown in FIG. 69 is arranged on the outer periphery of the second movable core 160. FIG. 13 is a partial cross-sectional view showing a configuration of a fuel injection device to which the fuel injection valve of the present embodiment is applied.

  As shown in FIG. 13, a step is formed on the outer peripheral portion of the second movable core 160 on the upper end portion 160 a side, and a gap is provided between the step and the inner periphery of the cylindrical member 18. . More specifically, among the outer circumferences on the upper end portion 160a side, the outer circumferences on the magnetization members 17 and 80 side are formed smaller than the outer circumference on the first movable core 50 side. Thereby, the level | step difference by a stepped outer periphery is formed in an outer peripheral part. A second urging member 269 is attached to the step.

    Next, functions and effects of the present embodiment will be described. (1) Even if configured in this way, the same effects as those of the first embodiment can be obtained.

  (2) Generally, in the case where the second movable core is magnetically attracted to the magnetized members 17 and 80 using the magnetic force generated in the drive coil, the cylindrical member 18 is driven from the drive coil disposed on the outer peripheral side of the cylindrical member 18. In addition to the magnetic flux flow indicated by the solid line in the figure flowing to the magnetized members 17, 80 and the second movable core, a leakage magnetic flux (broken line in the figure) that flows directly from the cylindrical member 18 to the second movable core may occur. .

  On the other hand, in the present embodiment, since the second urging member 269 is provided on the outer peripheral portion of the second movable core 160, it is possible to provide a gap between the tubular member 18 and the second movable core 160. . Therefore, leakage of magnetic flux that flows directly from the cylindrical member 18 to the second movable core 160 can be prevented.

  (3) In the present embodiment, a step due to the stepped outer periphery is provided on the outer peripheral portion of the second movable core 160 between the inner periphery of the cylindrical member 18 and the second biasing member 269 is It is preferable to be attached to the step.

  According to this, a step is provided between the outer periphery of the outer peripheral portion and the inner periphery of the cylindrical member 18, and the second urging member 269 is attached to the step, so that the second urging member 269 is moved to the second position. It can be attached to the core 160 so as to be urged, and a gap is reliably provided between the cylindrical member 18 and the second movable core 160.

(Other embodiments)
In the above-described embodiment, the magnetic members 17 and 80 have been described as magnetized members having the permanent magnets 80. However, as a method of driving the second movable core 60, the magnetized members are magnetic members made of a magnetic material. The magnetic member may be magnetized by a driving member such as a coil that generates a magnetic force by supplying current. In any configuration, the second movable core 60 can be attracted to the side opposite to the first movable core 50 in accordance with the direction of magnetic force of the drive coil (direction of the magnetic field).

  Furthermore, in the present embodiment described above, what is housed in the housing 15 and unitized together with the second movable core 60 has been described with the magnetizing members 17 and 80, but the magnetizing member is the direction of the magnetic force of the drive coil. Since the second movable core 60 can be attracted to the side opposite to the first movable core 50 according to the (magnetic field direction), any suction member that attracts the second movable core 60 by the magnetic force of the drive coil can be used. Good. The magnetizing members 17 and 80 described in the present embodiment described above constitute the attraction member described in the claims.

  In the present embodiment, the permanent magnet 80 and the magnetic body 17 are used to switch the lift amount of the needle 30. However, the present invention is not limited to using the permanent magnet 80 and the magnetic body 17, and Japanese Patent Application Laid-Open No. 2003-269289. It may be one that uses two drive coils as in the prior art when opened, and has two movable cores, and the axial movement amount of the other movable core is determined by the axial position of one movable core. In order to switch the lift amount of the needle by restricting, etc., any one may be used as long as the axial movement amount of these movable cores is set.

  Furthermore, in the present embodiment described above, the second movable core 60 and the magnetic members 17 and 80 housed in the housing 15 as a unit are combined with the needle 30 and the cylindrical member 18 serving as the fuel injection valve body. Insert assembled. The member or assembly structure that becomes the fuel injection valve body is not limited to the cylindrical member 18, but the internal components of the fuel injection valve 2 such as the needle 30 and the first movable core 50, the second movable core 60, and the magnetic member 17. , 80 as long as it is a casing that houses a housing 15 that is unitized.

  Furthermore, in the present embodiment described above, the configuration of the fuel injection valve to which the present invention is applied need not necessarily include a cylindrical member as long as it has the casing.

It is a fragmentary sectional view showing composition of a fuel injection device to which a fuel injection valve of a 1st embodiment of the present invention is applied. 2A and 2B are diagrams illustrating a unit including a suction member and a second movable core in FIG. 1, in which FIG. 2A is an exploded view of constituent members such as a suction member of the unit, and FIG. It is sectional drawing which shows this structure. It is a figure which shows the assembly | attachment process of one Example of the fuel injection valve in FIG. 1, Comprising: It is process drawing which shows the process of attaching a valve body to a casing. It is a figure which shows the assembly | attachment process of one Example of the fuel injection valve in FIG. 1, Comprising: It is process drawing which shows the process of inserting and assembling a needle and a unit in a casing. It is a figure which shows the assembly | attachment process of one Example of the fuel injection valve in FIG. 1, Comprising: The air gap between the 2nd movable core in a unit and the 1st movable core which cooperates with a needle becomes predetermined. Thus, it is process drawing which shows the process of press-fitting a unit in a casing. FIG. 2 is a diagram showing an assembly process of an embodiment of the fuel injection valve in FIG. 1, and after the air gap between the second movable core and the first movable core becomes predetermined, the unit and the casing are welded. It is process drawing which shows a process. It is a figure which shows the assembly | attachment process of one Example of the fuel injection valve in FIG. 1, Comprising: It is process drawing which shows the process of attaching a drive coil to a casing. FIG. 2 is a diagram illustrating an assembly process of an embodiment of the fuel injection valve in FIG. 1, wherein an urging member and an urging force adjusting member for urging the first movable core are inserted and assembled on the fuel introduction portion side of the casing. It is process drawing which shows a process. FIG. 2 is a diagram illustrating an assembly process of an embodiment of the fuel injection valve in FIG. 1, in which the biasing force adjusting member is introduced into the casing so that the biasing force of the biasing member to the first movable core is predetermined. It is process drawing which shows the process press-fit in the part side. It is a figure which shows the assembly | attachment process of one Example of the fuel injection valve in FIG. 1, Comprising: It is process drawing which shows the assembly completion state of a fuel injection valve. It is sectional drawing which shows the cylindrical member which comprises the casing of the fuel injection valve concerning 2nd Embodiment. It is a fragmentary sectional view showing the composition of the fuel injection device to which the fuel injection valve of a 3rd embodiment is applied. It is a fragmentary sectional view showing the composition of the fuel injection device to which the fuel injection valve of a 4th embodiment is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection apparatus 2 Fuel injection valve 12 Nozzle body (a part of valve body)
14 Valve seat 15 Housing 15a, 15b Inner circumference 15k Step part (locking part)
16 Valve housing (part of valve body)
17 Magnetic body (part of magnetized member)
18 Cylindrical member (casing)
18a, 18b 1st magnetic cylinder part, 2nd magnetic cylinder part 18c Nonmagnetic cylinder part 21 Injection hole 30 Needle (valve member)
31 Abutting portion 48 Fuel introduction portion 50 First movable core 59 First biasing member 60 Second movable core 60a, 60b Upper end portion, lower end portion 69 Second biasing member (biasing member)
70 coil (part of drive coil)
80 Permanent magnet (part of magnetized member, attracting member)
100 ECU (control means)
B Valve part S Electromagnetic drive part

Claims (13)

A casing,
A needle provided in the casing and seated on and seated on the valve seat;
A first movable core provided in the casing and movable in the axial direction together with the needle;
A second movable core that is provided in the casing and regulates a movement amount of the first movable core and is movable in an axial direction;
A drive coil provided in the casing and capable of acting a magnetic force on the first and second movable cores;
A suction member provided in the casing and sucking the second movable core;
In the fuel injection valve that makes the lift amount of the needle variable by making the movement amount of the first movable core variable according to the axial position of the second movable core,
A fuel injection valve comprising: a housing provided in the casing and housing the second movable core and the suction member to form a unit. The inner periphery of the housing has a locking portion for restricting the movement of the second movable core on the side opposite to the suction member,
The fuel injection valve according to claim 1, wherein the suction member is press-fitted into the inner periphery. The fuel injection valve according to claim 1 or 2, wherein the unit is press-fitted into the casing. An urging member for urging the second movable core in a seating direction of the needle;
4. The fuel injection valve according to claim 1, wherein the urging member is formed so as to be able to be inserted into the suction member. 5. An urging member for urging the second movable core in a seating direction of the needle;
The fuel injection valve according to any one of claims 1 to 3, wherein the urging member is accommodated so as to be sandwiched between the second movable core and the suction member. The fuel injection valve according to claim 5, wherein the biasing member is provided on an outer peripheral portion of the second movable core. The outer peripheral portion is provided with a step between the inner periphery of the casing,
The fuel injection valve according to claim 6, wherein the biasing member is attached to the step. 8. The magnetism member according to claim 1, wherein the attraction member is a magnetized member capable of attracting the second movable core to the side opposite to the first movable core according to the direction of the magnetic force of the drive coil. The fuel injection valve according to one item. The fuel injection valve according to claim 8, wherein the magnetizing member includes a permanent magnet and a magnetic body that can accommodate the permanent magnet therein. A needle that separates and sits on the valve seat; two movable cores; a suction member; and a cylindrical member that accommodates these members. Of the two movable cores, the second movable core on the suction member side Used for a fuel injection valve that varies the amount of movement of the first movable core according to the axial position,
In the fuel injection valve assembly method for adjusting the axial movement amount of the second movable core so that the lift amount of the needle spaced from the valve seat is variable,
Forming a housing for accommodating the second movable core and the suction member;
In the housing, the second movable core and the suction member are accommodated and unitized,
A method for assembling a fuel injection valve, wherein the axial movement amount of the second movable core is adjusted by a press-fitting amount for press-fitting the suction member into the housing. When housing the second movable core and the suction member in the housing and unitizing them,
11. The set of fuel injection valves according to claim 10, wherein a biasing member that biases the second movable core in a seating direction of the needle is sandwiched between the second movable core and the suction member. How to attach. The fuel injection valve according to claim 10 or 11 has a casing that houses the needle and the housing,
A method for assembling a fuel injection valve, wherein the needle and the unit are inserted and assembled in this order from the opening on the counter valve seat side of the casing toward the valve seat side. Before inserting and assembling the needle and the unit into the casing,
The fuel injection valve assembling method according to any one of claims 10 to 12, wherein a valve body having the valve seat is assembled and fixed to the casing.

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