JP4703697B2 - Electromagnetic actuator - Google Patents

Description

  The present invention relates to an electromagnetic actuator for driving a moving body, and more particularly to an electromagnetic valve provided with an electromagnetic actuator for reciprocating a valve.

[Conventional technology]
Conventionally, a valve that sits on and disengages from an orifice plate installed at the upper end of a fuel injection nozzle that injects fuel to an internal combustion engine, closes and opens the orifice, and reciprocates the valve in its axial direction. An injector solenoid valve equipped with an electromagnetic actuator is known.
Here, in order to improve the operation responsiveness of the electromagnetic actuator, there is a material using a composite sintered magnetic material as a material of a fixed core or a movable core that greatly affects the operation responsiveness.

As shown in FIG. 12, the composite sintered magnetic material is synthesized with a magnetic metal powder (eg, iron powder) 102 whose surface is covered with an insulating film (eg, oxide or synthetic resin film) 101 made of a non-magnetic material. A green compact (composite magnetic material) formed by compressing the resin powder 103 is compression-molded using a mold, and the composite magnetic material is formed of a composite sintered magnetic material sintered and hardened.
This composite sintered magnetic material has the advantage of less generation of eddy currents, but has the disadvantages of low strength and hardness and brittleness. For this reason, there is a possibility that the fixed core or the movable core made of composite sintered magnetic material is damaged by the collision energy that the fixed core attracts the movable core by the electromagnetic force generated in the coil and the movable core collides with the fixed core. there were.

Therefore, as shown in FIG. 13, a movable core that reciprocates the nozzle needle 55 of the fuel injection valve (injector) for the internal combustion engine in the axial direction thereof, and a bottomed cylindrical shape that is installed at the upper end of the fuel injection valve. First and second housings 111 and 112, electromagnetic coils 113 accommodated in the first and second housings 111 and 112, and a fixed core that attracts the movable core by electromagnetic force generated in the electromagnetic coils 113. An electromagnetic actuator has been proposed (see, for example, Patent Document 1).
The movable core of the electromagnetic actuator has a plunger-type armature 104 that directly drives the nozzle needle 55 accommodated in the injector body.

The fixed core of the electromagnetic actuator is made of a composite sintered magnetic material main stator 106 housed in the second housing 112, and a soft magnetic material arranged facing the armature side end face of the main stator 106. Sub-stator 107. In addition, an armature storage space 114 for movably storing the armature 104 and a stator storage space 115 for movably storing the main stator 106 are formed in the second housing 112. The main stator 106 is fixed to the second housing 112 by a cylindrical bar shaft-shaped shaft portion 116 formed integrally with the sub-stator 107.
The armature 104 has a sub-stator side end surface (magnetic pole surface) disposed opposite to the armature side end surface (magnetic pole surface) of the sub-stator 107 with a predetermined air gap (hereinafter abbreviated as a gap). Yes.

On the other hand, as shown in FIG. 14, the inner magnetic core 121 made of a magnetic material and the outer magnetic core 122 made of a magnetic material arranged on the outer side in the radial direction of the inner magnetic core 121 have 8 in the central axis direction. An electromagnetic fuel injection valve in which the slits 123 and 124 are formed at equal intervals is known (for example, see Patent Document 2).
In this electromagnetic fuel injection valve, since eight slits 123 and 124 are formed in the inner magnetic core 121 and the outer magnetic core 122 and are divided from each other, the drive flows through the electromagnetic coil 126 wound around the coil bobbin 125. When the current is turned off, eddy currents generated in the inner magnetic core 121 and the outer magnetic core 122 are not generated on the peripheral surface of the entire magnetic core, but are generated on the peripheral surface of each divided portion. Thereby, when the inner magnetic core 121 and the outer magnetic core 122 are divided into eight, the path of the eddy current becomes twice or more than the circumference of the magnetic core having a circular cross section that is not divided. That is, when the magnetic circuit is divided, the path of the eddy current becomes twice or more.

[Conventional technical problems]
However, in the electromagnetic actuator described in Patent Literature 1, the armature storage space 114 and the stator storage space 115 are connected via a gap formed between the outer peripheral surface of the sub-stator 107 and the inner peripheral surface of the second housing 112. Communicate.
Here, the armature storage space 114 is generally filled with fuel. Therefore, if a corrosive fuel is used as the fuel, for example, DME fuel (dimethyl ether fuel) or CNG gas fuel (liquefied natural gas fuel) is used, or a fuel containing corrosive components is used. Corrosive fuel flows from the armature storage space 114 into the stator storage space 115 through a gap formed between the outer peripheral surface of the sub-stator 107 and the inner peripheral surface of the second housing 112, and is a composite sintered magnetic material. There is a problem that the synthetic resin component (synthetic resin powder, synthetic resin film, etc.) contained in the composite sintered magnetic material is deteriorated by the corrosive fuel and the durability is lowered by touching the main stator 106 made of the above.

On the other hand, in the electromagnetic fuel injection valve described in Patent Document 2, a synthetic resin is molded between the outer periphery of the inner magnetic core 121 and the inner periphery of the outer magnetic core 122 and wound around the coil bobbin 125. An electromagnetic coil 126 is installed.
Further, a synthetic rubber O-ring that seals a gap between the terminal and the connector is mounted between the terminal connected to the terminal lead wire of the electromagnetic coil 126 and the connector. Accordingly, since the synthetic resin for molding the electromagnetic coil 126 and the O-ring made of synthetic rubber may come into contact with the fuel, the synthetic resin for molding the electromagnetic coil 126 when a corrosive fuel is used as the fuel. Further, there is a problem that the O-ring made of synthetic rubber is deteriorated by fuel and durability is lowered.
JP 2004-88891 A Japanese Utility Model Publication No. 5-83360

  An object of the present invention is to provide an electromagnetic actuator capable of enhancing durability by protecting a resin component (resin powder or the like) contained in a composite magnetic material from fuel, particularly corrosive fuel. .

  According to the first aspect of the present invention, the fixed core disposed to face the movable core of the electromagnetic actuator includes a main stator formed of a composite magnetic material obtained by solidifying metal powder and resin powder, and the main stator. The sub-stator is provided so as to be opposed to the end surface of the movable core and includes a soft magnetic material. This sub-stator is joined to the housing by welding all around. In the housing of the electromagnetic actuator, the second space that houses the main stator is hermetically or liquid-tightly sealed with respect to the first space that houses the movable core by the welded portion with the sub-stator.

  As a result, the airtightness of the second space for accommodating the main stator can be ensured with respect to the first space for accommodating the movable core, so that fuel filled in the first space, in particular, corrosive fuel, causes the main stator to pass through the main stator. The resin component (resin powder and the like) contained in the composite magnetic material to be configured and the resin parts accommodated in the second space are not directly touched. Accordingly, since the resin component (resin powder, etc.) and resin parts contained in the composite magnetic material can be protected from the fuel filled in the first space, particularly the corrosive fuel, the electromagnetic actuator, particularly the composite magnetic material is used. The durability of the main stator can be increased.

Further, the sub-stator is installed between the first space and the second space so as to partition the internal space of the housing into the first space and the second space.
Here, the sub-stator is disposed to face the end surface, outer peripheral surface, or inner peripheral surface of the housing. The sub-stator is installed so as to overlap the outer peripheral surface or inner peripheral surface of the housing in the radial direction. Further, the sub-stator is installed so as to overlap the end surface of the housing in the thickness direction (moving core moving direction, axial direction).
The housing further includes a bottomed cylindrical first metal pipe disposed radially inward of the main stator so as to cover the entire inner periphery of the main stator, and the main stator so as to cover the entire outer periphery of the main stator. Also has a cylindrical second metal pipe disposed outside in the radial direction . In particular, the first metal pipe is formed of a nonmagnetic material, and the open end side facing the movable core is configured as a stopper that regulates the full lift position of the movable core.
Thereby, since the first metal pipe is a non-magnetic material, it does not form a leakage magnetic path, and even if the restoring spring (coil spring) accommodated in the first metal pipe is made of a magnetic material, Since the restoring spring can block the leakage magnetic path from being formed, magnetic flux leakage does not occur. Furthermore, since the open end side of the first metal pipe of the non-magnetic material facing the movable core constitutes a stopper that regulates the full lift position of the movable core, there is no concern about residual magnetism when the coil is de-energized. May be.

According to the first aspect of the present invention, the sub-stator has an annular first magnetic part installed so as to contact the first metal pipe, and an annular stator installed so as to contact the second metal pipe. It has the 2nd magnetic part. And the 1st magnetic part is joined to the 1st metal pipe by all-around welding. Moreover, the 2nd magnetic part is joined to the 2nd metal pipe by the perimeter welding.
As a result, the housing of the electromagnetic actuator is formed in the first space that houses the movable core by the welded portion between the first metal pipe and the first magnetic portion and the welded portion between the second metal pipe and the second magnetic portion. The second space that houses the main stator is hermetically or liquid-tightly sealed.

According to the second aspect of the present invention, in the sub-stator, the magnetic flux leaks between the first magnetic part and the second magnetic part between the outer periphery of the first magnetic part and the inner periphery of the second magnetic part. It has a magnetoresistive part made of a non-magnetic material to prevent this.
The magnetoresistive portion is joined to the first magnetic portion by all-around welding, and is joined to the second magnetic portion by all-around welding.
Thereby, the housing of the electromagnetic actuator includes a welded portion between the first metal pipe and the first magnetic portion, a welded portion between the second metal pipe and the second magnetic portion, a welded portion between the first magnetic portion and the magnetic resistance portion, The second space that houses the main stator is hermetically or liquid-tightly sealed with respect to the first space that houses the movable core by the welded portion between the second magnetic portion and the magnetic resistance portion.
According to the invention of claim 3 , in the sub-stator, the magnetic flux leaks between the first magnetic part and the second magnetic part between the outer periphery of the first magnetic part and the inner periphery of the second magnetic part. It has a magnetoresistive portion made of a soft magnetic material that suppresses the above.
The magnetoresistive portion is a thin portion (magnetic diaphragm) that is thinner than the first magnetic portion and the second magnetic portion.

According to the fourth aspect of the present invention, the movable core that drives the moving body, that is, moves the moving body in the moving direction (axial direction) is spaced apart from the sub-stator (the armature side end surface). The armatures are arranged opposite to each other. A plurality of radial first slits extending from the inner peripheral portion of the sub-stator to the outer peripheral portion of the sub-stator are formed on the end surface on the main stator side of the sub-stator, and the outer peripheral portion of the sub-stator from the inner peripheral portion of the sub-stator to the armature-side end surface of the sub-stator A plurality of radial second slits extending to the end are formed.
According to the fifth aspect of the present invention, the first slit and the second slit are formed in the first slit between the two adjacent first slits when the sub stator is viewed from outside in the radial direction of the sub stator. On the other hand, the first slits and the second slits are alternately arranged in the sub-stator so that the second slits cut in the opposite direction are provided.

According to invention of Claim 6, a 1st slit is the depth which does not penetrate a substator in the plate | board thickness direction. The second slit has a depth that does not penetrate the sub-stator in the plate thickness direction. The depth of the first slit is at least half the plate thickness of the sub-stator. The depth of the second slit is at least half the plate thickness of the sub-stator.
According to the invention described in claims 4 to 6, it can be prevented from becoming all around the magnetic path in each cross section of Sabusuteta. As a result, the eddy current path becomes longer than that of the sub-stator of the type in which no slit is formed, so that the electrical resistance is increased and the eddy current loss of the sub-stator can be reduced. Accordingly, the attractive force of the movable core by the fixed core (main stator, sub-stator) can be improved without increasing the coil outer diameter of the electromagnetic coil, so that the operation responsiveness of the electromagnetic actuator can be improved.

According to the seventh aspect of the present invention, the movable core that drives the moving body, that is, moves the moving body in the moving direction (axial direction) is spaced apart from the sub-stator (the armature side end face). The armatures are arranged opposite to each other. A plurality of radial slits extending from the inner periphery of the sub-stator to the outer periphery of the sub-stator are formed on the armature-side end surface of the sub-stator.
According to invention of Claim 8 , a slit is the depth which does not penetrate a sub-stator in the plate | board thickness direction. The depth of the slit is at least half the thickness of the sub-stator.
According to the seventh and eighth aspects of the invention, it is possible to prevent the entire stator magnetic path from being formed in each cross section of the sub-stator. As a result, the eddy current path becomes longer than that of the sub-stator of the type in which no slit is formed, so that the electrical resistance is increased and the eddy current loss of the sub-stator can be reduced. Accordingly, the attractive force of the movable core by the fixed core (main stator, sub-stator) can be improved without increasing the coil outer diameter of the electromagnetic coil, so that the operation responsiveness of the electromagnetic actuator can be improved.

According to the ninth aspect of the present invention, the moving body driven by the movable core is a valve of an electromagnetic valve for an injector. This valve is driven in the valve opening operation direction or the valve closing operation direction by the movable core.

  The best mode for carrying out the present invention is to increase the durability of an electromagnetic actuator by protecting resin components (resin powder, etc.) contained in a composite magnetic material from fuel, particularly corrosive fuel. The welded portion (joint portion) between the housing and the sub-stator is joined by all-around welding, and the second space containing the main stator is hermetically sealed against the first space containing the movable core. It was realized by doing.

[Configuration of Example 1]
1 to 4 show a first embodiment of the present invention, FIG. 1 is a view showing an injector, FIG. 2 is a view showing an electromagnetic valve for an injector, and FIG. 3 is a view showing an electromagnetic actuator. FIG. 4 is a view showing a sub-stator (magnetic + nonmagnetic plate).

The fuel injection device of the present embodiment is a common rail fuel injection system (accumulation fuel injection device) known as a fuel injection system for an internal combustion engine (engine) such as a diesel engine having a plurality of cylinders.
In this common rail fuel injection system, a fuel supply pump (supply pump) that pressurizes fuel to increase pressure, a common rail that accumulates high pressure fuel pumped from the supply pump, and high pressure fuel is distributed and supplied from the common rail. A plurality of injectors, and configured to inject and supply high-pressure fuel accumulated in the common rail into the combustion chamber of each cylinder of the engine via each injector.

  The injector of the present embodiment is mounted corresponding to each cylinder of the engine, and is a direct injection type fuel injection for an internal combustion engine that supplies high pressure fuel accumulated in the common rail in a mist form directly into the combustion chamber. It is a valve. The injector is connected to a downstream end in a fuel flow direction of a plurality of injector pipes branched from a common rail, and performs fuel injection into a combustion chamber for each cylinder of the engine, and a valve body of the fuel injection nozzle This is an electromagnetic fuel injection valve composed of an injector solenoid valve or the like that drives the valve in the valve opening operation direction.

Here, the injector of the present embodiment has an orifice plate (valve seat) 3 sandwiched between an injector body (lower body) 1 that is a housing of a fuel injection nozzle and a valve body 2 that is a housing of an electromagnetic valve. By fastening and fixing the flange housing 4 to the outer periphery of the rear end portion (the upper end portion in the figure) of the injector body 1 in the axial direction, the fuel injection nozzle and the electromagnetic valve are integrally coupled.
The fuel injection nozzle includes an injector body 1, a nozzle needle 5 that opens and closes a plurality of injection holes, a nozzle body 6 that slidably accommodates the nozzle needle 5, and a rear end portion in the axial direction of the nozzle needle 5 (illustrated). And a command piston 7 slidably accommodated in the injector body 1.
The solenoid valve includes an orifice plate 3 assembled at the rear end portion (the upper end portion in the figure) of the fuel injection nozzle in the axial direction, and a valve that can be seated on and removed from the orifice plate 3 (a valve body of the solenoid valve). 10 and an electromagnetic actuator for driving the valve 10.

  The electromagnetic actuator is a movable core that drives the valve 10, which is a valve body of the electromagnetic valve, in the valve opening operation direction or the valve closing operation direction, and the direction in which the movable core is pressed together with the valve 10 against the valve seat of the orifice plate 3 And a cylindrical electromagnet that generates an electromagnetic force that attracts the movable core. The electromagnet includes a solenoid coil (electromagnetic coil) 12 that generates a magnetic attraction force (electromagnetic force) between the movable core and the fixed core when supplied with electric power, and the movable core by the electromagnetic force generated in the electromagnetic coil 12. It is comprised by the fixed core etc. which attracts.

Here, the movable core of the electromagnetic actuator that drives the valve 10 of the electromagnetic valve is a flat plate that is disposed to face the armature side end surface (the magnetic pole surface of the electromagnet) of the sub-stator 17 of the fixed core with a predetermined gap therebetween. A mold armature 14 and a shaft (armature stem) 15 slidably supported in the axial direction by the valve body 2 are provided.
The fixed core of the electromagnetic actuator includes a main stator 16 made of a composite sintered magnetic material that accommodates the electromagnetic coil 12 therein, and a soft magnetic material (soft magnetic steel material) and a non-magnetic material disposed on the armature side of the main stator 16. A sub-stator 17 made of a material is used.
The details of the injector solenoid valve using the electromagnetic actuator of this embodiment will be described later.

The nozzle needle 5 of the fuel injection nozzle opens and closes a plurality of injection holes formed in the nozzle body 6.
The nozzle body 6 and the injector body 1 are formed in a cylindrical shape from a metal material such as chromium / molybdenum steel or low carbon steel.
A plurality of injection holes for injecting high-pressure fuel into the combustion chamber for each cylinder of the engine are formed on the tip end side in the axial direction of the nozzle body 6. In addition, a fuel reservoir chamber 21 is formed in the central portion of the nozzle body 6 in the axial direction. A pressure control chamber 22 is formed on the rear end side (the upper end side in the drawing) of the injector body 1 in the axial direction. A coil spring (needle biasing means) 23 that biases the nozzle needle 5 in the valve closing direction is accommodated in the front end portion (lower end portion in the drawing) of the injector body 1 in the axial direction.

The nozzle body 6 and the injector body 1 enter the fuel reservoir chamber 21 and the pressure control chamber 22 through a bar filter that captures foreign matters mixed in the fuel from the inlet port of the pipe joint connected to the common rail. A fuel supply passage (high pressure fuel passage) 24 for supplying high pressure fuel is formed.
The orifice plate 3 is assembled to the peripheral edge of the opening of the pressure control chamber 22. In addition, inlet-side and outlet-side orifices 25 and 26 for adjusting the flow rate of the passing fuel are formed in the orifice plate 3.

The pressure control chamber 22 communicates with the fuel supply passage 24 through an inlet-side orifice 25 formed in the orifice plate 3. The pressure control chamber 22 communicates with the outlet 28 or the armature storage space 41 via the outlet-side orifice 26, the solenoid valve-side valve storage chamber, and the fuel discharge passage 27.
Further, a fuel recovery passage is formed inside the injector body 1 so that surplus fuel flows from a spring housing space 29 that houses the coil spring 23.
Excess fuel that has flowed into the fuel recovery passage is returned to the fuel tank via the fuel discharge passage on the solenoid valve side and the outlet 28.

Further, as shown in FIGS. 1 and 2, a cylindrical portion 31 is provided at the rear end portion in the axial direction of the injector body 1 so as to protrude upward in the drawing. On the inner periphery of the cylindrical portion 31, an inner peripheral screw portion that is screwed into the outer peripheral screw portion of the valve body 2 on the solenoid valve side is formed. Further, on the outer periphery of the cylindrical portion 31, an outer peripheral screw portion that is screwed into the inner peripheral screw portion of the flange housing 4 on the solenoid valve side is formed.
The cylindrical portion 31 has a flat contact surface (opposite surface) disposed opposite to the lower end surface (contact surface) of the intermediate spacer 33 described later, and the annular end surface of the cylindrical portion 31 of the injector body 1. And the intermediate spacer 33 is sandwiched between the annular end surface of the stepped portion 32 of the flange housing 4, whereby the contact surface of the cylindrical portion 31 and the contact surface of the intermediate spacer 33 are surface-sealed.

Next, details of the electromagnetic valve for an injector using the electromagnetic actuator of this embodiment will be described with reference to FIGS.
As described above, the electromagnetic valve of the present embodiment is constituted by the valve body 2, the orifice plate 3, the flange housing 4, the valve 10, and the electromagnetic actuator. The electromagnetic actuator is disposed to face the movable core (armature 14) that drives the valve 10 of the electromagnetic valve in the valve opening operation direction or the valve closing operation direction with a predetermined gap between the movable core and the movable core. A fixed core (main stator 16, sub-stator 17), a housing having an internal space for accommodating the movable core and the fixed core, and an electromagnetic coil 12 that is held inside the housing and generates electromagnetic force when supplied with electric power; It has.

  The valve 10 is a spherical body-shaped valve body (ball valve) that is held on the distal end side of the shaft 15 of the movable core. The spherical body (ball) shape is made of a metal material such as chromium-molybdenum steel or low-carbon steel. Is formed. The valve 10 closes the outlet-side orifice 26 that functions as a valve hole of the electromagnetic valve by being seated on and removed from the opening peripheral edge of the outlet-side orifice 26 of the orifice plate 3 (the valve seat of the orifice plate 3). Open. Further, the valve 10 has a valve fully closed position that is seated on the orifice plate 3 and closes the outlet side orifice 26 by an electromagnetic actuator, and a valve fully opened position that is separated from the orifice plate 3 and opens the outlet side orifice 26. Driven to 2 position.

Here, the housing of the electromagnetic actuator includes a lower housing (valve body 2, orifice plate 3) made of nonmagnetic steel, a flange housing 4 made of nonmagnetic steel, and a cup-shaped stopper (bottomed tube made of nonmagnetic steel). First metal pipe 18), a cylindrical intermediate housing (cylindrical second metal pipe) 19 made of nonmagnetic steel or magnetic steel, an upper housing 20 made of nonmagnetic steel, and nonmagnetic steel. And an annular intermediate spacer 33.
The housing of the electromagnetic actuator has an internal space that accommodates the movable core (armature 14) and the fixed core (main stator 16, sub-stator 17). The internal space of the housing has an armature storage space (first space) 41 for storing at least the armature 14 together with fuel in the movable core, and a stator storage space (second space) 42 for storing the main stator 16. . A cylindrical coil housing space 43 that houses the electromagnetic coil 12 is formed inside the main stator 16. A spring housing space 44 for housing the coil spring 11 is formed inside the stopper 18.

Here, the armature storage space 41 of the present embodiment is a disk-shaped space, and includes a wall surface (an end face on the armature side) facing the armature storage space 41 of the valve body 2 and a magnetic pole surface of the electromagnet (the armature storage of the sub-stator 17). And a wall surface facing the inside of the space 41: an armature side end surface). The outer peripheral portion of the armature storage space 41 is covered with an inner wall surface (an inner wall surface surrounding the outer periphery of the armature 14 in the circumferential direction) facing the armature storage space 41 of the cylindrical portion 31 of the injector body 1.
Further, the stator storage space 42 of the present embodiment is a cylindrical space, and includes a wall surface facing the stator storage space 42 of the sub-stator 17 (a main stator side end surface) and a wall surface facing the stator storage space 42 of the upper housing 20. (Main stator side end surface). The inner peripheral portion of the stator storage space 42 is covered with a wall surface (outer peripheral surface) facing the stator storage space 42 of the stopper 18. In addition, the outer peripheral portion of the stator storage space 42 is covered with a wall surface (inner peripheral surface) facing the stator storage space 42 of the intermediate housing 19.

  The valve body 2 is formed in a cylindrical shape by a nonmagnetic steel material (for example, chromium / molybdenum steel). A fuel discharge passage 27 is formed in the valve body 2. Further, the valve body 2 forms an armature housing space 41 for housing fuel together with the armature 14 between the magnetic pole surface of the sub-stator 17 of the electromagnet and the lift restricting surface of the stopper 18. A sliding hole (through hole) through which the movable core shaft 15 slides is formed on the central axis of the valve body 2. Further, a valve accommodating chamber having an opening diameter larger than the diameter of the sliding hole is provided at the opening end of the sliding hole on the orifice plate side. Further, in order to reduce the bounce when the solenoid valve is closed, the opening end of the sliding hole on the armature side has a flow resistance force (oil tight damper action) between the valve body 2 and the armature 14. A circular recess for accommodating the clearance adjustment plate 34 is formed.

  The flange housing 4 is formed in a cylindrical shape by a nonmagnetic steel material (for example, chromium / molybdenum steel). The flange housing 4 has an inner peripheral screw portion that is screwed into the outer peripheral screw portion of the cylindrical portion 31 of the injector body 1. Further, the flange housing 4 has a thick part on the upper side in the figure from the step part 32, and has a thin part thinner than the thick part on the lower side in the figure from the step part 32. Note that an O-ring 45 made of synthetic rubber is provided between the inner periphery of the flange housing 4 and the outer periphery of the upper housing 20 to ensure airtightness.

The movable core of the present embodiment is composed (formed) of pure iron, low carbon steel, or ferritic magnetic stainless steel (SUS13) as an example of soft magnetic steel. This movable core is an integral part in which a solid cylindrical shaft 15 and a disk-type armature 14 are integrated, and the same direction as the moving direction of the solenoid valve 10 (the central axis direction of the solenoid valve). The magnetic movable body (moving core) which reciprocates is comprised.
The shaft 15 of the movable core protrudes from the central portion of the armature 14 on the side opposite to the sub-stator side toward the distal end side (the lower side in the drawing) in the axial direction. The shaft 15 is slidably supported in the sliding hole of the valve body 2. In addition, the valve 10 is incorporated in the concave portion at the end of the shaft 15 in the axial direction.

The armature 14 of the movable core has a magnetic pole surface disposed on the sub-stator side end surface (upper end surface in the drawing) opposite to the electromagnet magnetic pole surface (the magnetic pole surface of the sub-stator 17) with a predetermined gap therebetween. ing. The armature 14 is formed with a plurality of through holes penetrating the armature 14 in the axial direction (the thickness direction of the armature 14). These through holes are formed in order to release unnecessary fuel sandwiched between the magnetic pole surface of the sub-stator 17 of the electromagnet and the magnetic pole surface of the armature 14 when the armature 14 comes into contact with the restriction surface of the stopper 18. Yes.
The shaft 15 and the armature 14 may be configured as separate parts, and both may be coupled by press-fitting or welding. In this case, a bearing steel and a non-magnetic material having excellent sliding resistance may be used as the material of the shaft 15.

The movable core is attracted to the magnetic pole surface side of the sub-stator 17 by the electromagnetic force of the electromagnetic coil 12, and moves in the valve opening operation direction (upper side (one side) in the axial direction of the electromagnetic actuator: upper side in the drawing). As a result, the valve 10 is separated from the valve seat of the orifice plate 3 to open the outlet-side orifice 26.
When the energization of the electromagnetic coil 12 is stopped, the movable core is closed by the urging force (spring load) of the coil spring 11 (the lower side in the axial direction of the electromagnetic actuator (the other side): the lower side in the drawing. ) To press the valve 10 against the orifice plate 3. As a result, the valve 10 is seated on the valve seat of the orifice plate 3 to close the outlet-side orifice 26.

That is, the illustrated upper end surface of the orifice plate 3 is movable when the movable core is pushed back by the biasing force of the coil spring 11 and moved toward the valve seat (illustrated upper end surface) side of the orifice plate 3. This is used as a first restriction surface for restricting the amount of movement of the core armature 14. Thereby, when the valve 10 is seated on the first restriction surface of the orifice plate 3, further movement of the valve 10 and the movable core is restricted. That is, the position of the valve 10 becomes the default position. Along with this, the position of the armature 14 is regulated at the default position.
Therefore, the electromagnetic valve of the present embodiment constitutes a normally closed type (normally closed type) electromagnetic on-off valve.

The electromagnet includes an electromagnetic coil 12 that generates a magnetic flux when energized, and a fixed core (main stator 16 and sub-stator 17) that is magnetized when an excitation current (injector drive current) flows through the electromagnetic coil 12. ing.
The electromagnetic coil 12 is a solenoid coil that generates a magnetic attractive force (electromagnetic force) between the movable core (armature 14) and the fixed core (main stator 16, sub-stator 17) when supplied with electric power. The electromagnetic coil 12 has a conductive bobbin 13 made of synthetic resin wrapped around a conductive wire with an insulating coating a plurality of times. The coil bobbin 13 is a resin molded part housed in the coil housing space 43 of the main stator 16.
The electromagnetic coil 12 wound around the coil bobbin 13 in the coil housing space 43 of the main stator 16 is molded by a synthetic resin (mold resin).

The electromagnetic coil 12 has a coil portion wound between a pair of hook-shaped portions of the coil bobbin 13 and a pair of terminal lead wires taken out from the coil portion.
A pair of external connection terminals (stud bolts) 47 are electrically connected to the pair of terminal lead wires drawn out from the electromagnetic coil 12 via the pair of terminals 46.
The pair of terminals 46 are installed so as to penetrate through terminal through holes 48 formed in the upper housing 20 in the axial direction thereof. And the electromagnetic coil 12 and the terminal 46 are electrically connected by winding the terminal lead wire of the electromagnetic coil 12 around the 1st coupling part of the terminal 46, and performing heat caulking. The pair of stud bolts 47 are held and fixed in the connector housing 49 with the bolt shafts protruding from the end surface (the upper end surface in the figure) of the connector housing (terminal resin) 49 made of synthetic resin. These stud bolts 47 are electrically connected to the second joint portion of the terminal 46 by welding or the like via a bridge terminal (not shown).

Here, in the solenoid valve of the present embodiment, in order to prevent poor response due to residual magnetism after the exciting current flowing through the electromagnetic coil 12 is cut off, even when the armature 14 of the movable core is fully lifted, the magnetic pole surface of the armature 14 An appropriate axial gap (gap) is ensured between the magnetic pole surface of the sub-stator 17. This gap is secured by the stopper 18.
The stopper 18 of the present embodiment is configured (formed) by chromium-molybdenum steel (SCM415 or the like) as an example of a nonmagnetic steel material. The stopper 18 is a bottomed cylindrical nonmagnetic metal pipe that is open at the other end (lower end in the figure) and closed at one end (upper end in the figure). The stopper 18 houses the main stator 16 in the stator housing space 42 so as to guide the inner peripheral portion of the main stator 16. The stopper 18 is disposed radially inward of the inner periphery of the main stator 16 of the electromagnet.
And the stopper 18 is arrange | positioned so that it may contact or oppose with respect to the inner peripheral part (inner peripheral surface) of the sub-stator 17 of a fixed core.

The stopper 18 is an armature stopper that regulates the full lift position of the movable core, particularly the armature 14, and a predetermined cylindrical gap is formed between the inner peripheral surface (inner wall surface) of the main stator 16 of the electromagnet. A coil spring 11 that urges the valve 10 and the movable core in a direction (valve closing operation direction) to press the valve 10 and the movable core against the valve seat of the orifice plate 3 is accommodated in the stopper 18 (spring storage space 44).
The tip end surface (lower end surface in the drawing) of the stopper 18 is movable when the movable core is drawn upward by the electromagnetic force of the electromagnetic coil 12 and moved to the magnetic pole surface side of the sub-stator 17. It is used as a lift restricting surface for restricting the full lift position of the core armature 14. Thereby, when the armature 14 contacts the lift restricting surface of the stopper 18, further movement of the movable core is restricted. That is, the position of the armature 14 is the full lift position. Along with this, the lift position of the valve 10 is also regulated at the full lift position.

The lift restricting surface of the stopper 18 and the magnetic pole surface of the electromagnet sub-stator 17 are formed flush with each other. Note that the lift restricting surface of the stopper 18 and the magnetic pole surface of the sub-stator 17 are not limited to be flush with each other, and the lift restricting surface of the stopper 18 protrudes to the armature side from the magnetic pole surface of the sub-stator 17. May be.
The stopper 18 is preferably formed of a nonmagnetic steel material (nonmagnetic metal) in order to prevent a response failure due to residual magnetism after the exciting current flowing through the electromagnetic coil 12 is interrupted. Further, the stopper 18 has a cylindrical outer peripheral surface (an outer surface in the radial direction with respect to the opening of the spring storage space 44) that is installed facing the inner peripheral surface of the sub-stator 17. Further, the outer peripheral surface of the stopper 18 is in contact with the inner peripheral surface of the sub-stator 17. The stopper 18 is joined to the inner peripheral surface of the sub-stator 17 by all-around laser welding.

The intermediate housing 19 of the present embodiment is configured (formed) by chromium-molybdenum steel (SCM415 or the like) as an example of a nonmagnetic steel material. The intermediate housing 19 is a cylindrical nonmagnetic metal pipe that is open at both ends. The intermediate housing 19 may be made of nonmagnetic steel (nonmagnetic metal) or magnetic steel (magnetic metal).
The intermediate housing 19 houses the main stator 16 in the stator housing space 42 so as to guide the outer peripheral portion of the main stator 16. The intermediate housing 19 is installed so as to cover the entire outer periphery of the main stator 16 of the electromagnet, that is, so as to surround the periphery of the main stator 16 in the circumferential direction, and is disposed on the outer side in the radial direction from the outer peripheral surface of the main stator 16. Has been.

The intermediate housing 19 is arranged so as to contact or face the outer peripheral portion of the sub-stator 17 of the electromagnet (particularly the outer peripheral edge of the end surface on the main stator side). The intermediate housing 19 is disposed so as to contact or face the outer peripheral portion of the upper housing 20 (particularly, the outer peripheral surface on the main stator side).
The intermediate housing 19 has a cylindrical large diameter portion (cylindrical portion) having a large inner diameter and a small cylindrical diameter portion (cylindrical portion) having a small inner diameter. On the outer periphery of the step portion formed between the large diameter portion and the small diameter portion, an annular flange 50 sandwiching the intermediate spacer 33 between the annular end surface of the cylindrical portion 31 of the injector body 1 is radially outward. It protrudes toward

The flange 50 is sandwiched between the annular end surface of the cylindrical portion 31 of the injector body 1 and the annular end surface of the stepped portion 32 of the flange housing 4 with the intermediate spacer 33 interposed therebetween. Further, the flange 50 has a flat contact surface (facing surface) disposed opposite to the illustrated upper end surface (contact surface) of the intermediate spacer 33, and the annular end surface of the cylindrical portion 31 of the injector body 1 and the flange housing. When the intermediate spacer 33 is sandwiched between the annular end surface of the four step portions 32, the contact surface of the intermediate spacer 33 and the contact surface of the flange 50 are surface-sealed.
The large diameter portion of the intermediate housing 19 is formed in a cylindrical shape so as to cover the outer peripheral surface of the main stator 16 and the outer peripheral surface of the upper housing 20. The large-diameter portion of the intermediate housing 19 has an inner peripheral surface that is disposed to face the outer peripheral surface of the main stator 16 and the outer peripheral surface of the upper housing 20. The inner peripheral surface of the large diameter portion of the intermediate housing 19 is in contact with the outer peripheral surface of the upper housing 20. The large-diameter portion of the intermediate housing 19 is joined to the outer peripheral surface of the upper housing 20 by all-around laser welding.

  A small-diameter portion of the intermediate housing 19 is formed in a cylindrical shape so as to cover the outer peripheral surface of the main stator 16. The small-diameter portion of the intermediate housing 19 is an annular annular tip surface (an annular end surface on the armature side of the small-diameter portion of the intermediate housing 19) that is installed to face the main stator side end surface (outer peripheral side end surface) of the sub-stator 17. )have. Further, the annular tip end surface on the armature side of the small-diameter portion of the intermediate housing 19 is in contact with the outer peripheral side end surface of the sub-stator 17. The small-diameter portion of the intermediate housing 19 is joined to the outer peripheral side end surface of the sub-stator 17 by full-circle laser welding. Thereby, the main stator 16 and the stopper 18 are held and fixed between the sub-stator 17 and the intermediate housing 19 and the upper housing 20.

The intermediate spacer 33 is configured (formed) by nonmagnetic stainless steel (SUS303 or the like) as an example of a nonmagnetic steel material. The intermediate spacer 33 is formed in an annular shape so as to surround the vicinity of the flange 50 of the intermediate housing 19 in the circumferential direction. The intermediate spacer 33 is a lift adjusting intermediate spacer that determines the full lift amount of the armature 14 of the movable core according to its thickness, and the annular end surface of the cylindrical portion 31 of the injector body 1 and the annular end surface of the flange 50 of the intermediate housing 19. It is sandwiched between.
An annular recess (a depression or a groove) is formed on the contact surface (the upper end surface in the drawing) of the intermediate spacer 33 to increase the seal surface pressure with the contact surface of the flange 50 of the intermediate housing 19. Further, an annular recess (depression, groove) for increasing the seal surface pressure between the intermediate spacer 33 and the contact surface of the cylindrical portion 31 of the injector body 1 is formed on the contact surface (lower end surface in the drawing). .

  Then, by screwing the flange housing 4 into the outer peripheral thread portion of the cylindrical portion 31 of the injector body 1, the flange 50 of the intermediate housing 19 is pressed against the annular end surface of the cylindrical portion 31 of the injector body 1 with the intermediate spacer 33 interposed therebetween. . Then, the main stator 16, the sub-stator 17, the stopper 18 and the upper housing 20 are positioned with respect to the injector body 1. As a result, the axial distance between the valve seat of the orifice plate 3 sandwiched between the injector body 1 and the valve body 2 and the magnetic pole surface of the sub-stator 17 and the restriction surface of the stopper 18 is determined, and the valve 10 and the armature 14 are determined. The full lift amount is set.

  The upper housing 20 is formed in a cylindrical shape using, for example, a nonmagnetic steel material (for example, SCM415). The upper housing 20 has a terminal through hole 48 penetrating in the axial direction so as to communicate the upper end surface (connector side end surface) and the lower end surface (main stator side end surface). Since the terminal through hole 48 is opened by a wall surface facing the stator storage space 42, it communicates with the stator storage space 42. A metal terminal 46, a synthetic resin insulating bush 51 and a synthetic rubber O-ring 52 are inserted into the terminal through-hole 48.

The insulation bush 51 is formed in a cylindrical shape and is an insulator that ensures electrical insulation between the upper housing 20 and the terminal 46. The O-ring 52 is a sealing material that ensures airtightness between the upper housing 20 and the terminal 46.
Further, the end surface on the main stator side of the upper housing 20 is disposed so as to face the end surface (upper end surface in the drawing) opposite to the end surface on the armature side of the main stator 16. In addition, a stopper fitting hole for press-fitting (press-fitting) the upper side (closed portion side) of the stopper 18 in which the spring housing space 44 is formed in the center portion of the end surface on the main stator side of the upper housing 20. (Press-fit hole) 53 is formed.

  As described above, the fixed core of the electromagnetic actuator includes the main stator 16 made of a composite sintered magnetic material, the sub-stator 17 configured to include a soft magnetic steel material, and the like. The main stator 16 and the sub-stator 17 are magnetic fixed bodies (stator cores) that are magnetized together with the armature 14 of the movable core when the electromagnetic coil 12 is energized. The main stator 16 and the sub-stator 17 form a magnetic circuit with the electromagnetic coil 12 and the armature 14.

  The main stator 16 includes a magnetic metal powder (for example, iron powder) whose surface is covered with an insulating film made of a nonmagnetic material (for example, an oxide or a synthetic resin film) and a synthetic resin powder (for example, polyphenylene sulfide: PPS having excellent heat resistance). Alternatively, a compact sintered magnetic material obtained by compressing and compacting a green compact (composite magnetic material) formed by compressing polyimide resin (PI) using a mold, and sintering and compressing the compression molded composite magnetic material. It becomes more. This composite sintered magnetic material has the advantage of less eddy current generation, but has the disadvantages of low strength and hardness and brittleness.

  The main stator 16 has an inner peripheral side core portion, an outer peripheral side core portion, and a connecting portion (upper end portion) that connects both the core portions, and the outer periphery of the inner peripheral side core portion and the inner periphery of the outer peripheral side core portion, A coil storage space 43 is formed so as to be sandwiched therebetween. The inner peripheral core portion and the outer peripheral core portion are formed in a cylindrical shape. Moreover, the electromagnetic coil 12 and the coil bobbin 13 are accommodated in the coil storage space 43 formed between the outer periphery of the inner peripheral side core portion and the inner periphery of the outer peripheral side core portion. Further, the outer peripheral side core portion, that is, the outer diameter side in the radial direction from the coil housing space 43 of the main stator 16 is protected by a cylindrical intermediate housing 19.

  Here, the main stator 16 is formed in a bottomed double cylindrical shape having a step portion corresponding to the step portion 54 of the intermediate housing 19, and is inserted on the inner peripheral side of the intermediate housing 19. The outer periphery of the core portion on the outer peripheral side of the main stator 16 is reduced in diameter toward the lower side of the figure with the stepped portion as a boundary. The stepped portion abuts on the stepped portion 54 provided on the inner peripheral side of the intermediate housing 19, thereby preventing the main stator 16 from falling off the intermediate housing 19.

  The sub-stator 17 is an annular plate-shaped magnetic plate (magnetic + non-magnetic plate) disposed to face the armature side end surfaces of the inner peripheral side core portion and the outer peripheral side core portion of the main stator 16. Further, the sub-stator 17 has a magnetic pole surface (an armature side end surface) opposed to the magnetic pole surface of the armature 14 of the movable core with a predetermined gap. The sub-stator 17 is installed between the armature storage space 41 and the stator storage space 42 so as to divide the internal space of the electromagnetic actuator housing into the armature storage space 41 and the stator storage space 42.

The sub-stator 17 includes first and second magnetic rings 61 and 62 made of a soft magnetic steel material and a nonmagnetic ring 64 made of a nonmagnetic steel material.
The first and second magnetic rings 61 and 62 are composed (formed) of silicon steel in which silicon is contained in iron as an example of a soft magnetic steel material. In this embodiment, silicon steel (1LSS to 3LSS) having a silicon content of 1 to 3 mass is used.

The first magnetic ring 61 is an annular first magnetic portion that is disposed on the outer side in the radial direction from the stopper 18 so as to cover the outer periphery of the stopper 18 in the vicinity of the lift restricting surface. The first magnetic ring 61 is installed so as to be in direct contact with the outer peripheral surface of the tip of the stopper 18, and is joined to the outer peripheral surface of the tip of the stopper 18 by laser welding all around.
The second magnetic ring 62 is an annular second magnetic portion disposed on the outer side in the radial direction from the first magnetic ring 61 and the nonmagnetic ring 64 so as to cover the entire outer periphery of the nonmagnetic ring 64. The second magnetic ring 62 is installed so as to be in direct contact with the armature-side annular end surface (annular tip surface) of the small-diameter portion of the intermediate housing 19, and is joined to the annular tip surface of the intermediate housing 19 by all-around laser welding. Has been.

  The nonmagnetic ring 64 is configured (formed) by nonmagnetic stainless steel (SUS304 or the like) as an example of a nonmagnetic steel material. The nonmagnetic ring 64 is installed between the outer periphery of the first magnetic ring 61 and the inner periphery of the second magnetic ring 62, and is more than the first magnetic ring 61 so as to cover the entire outer periphery of the first magnetic ring 61. An annular nonmagnetic portion (magnetic resistance portion) that is arranged on the outer side in the radial direction and arranged on the inner side in the radial direction with respect to the second magnetic ring 62 so as to cover the entire inner circumference of the second magnetic ring 62. is there.

  And the nonmagnetic ring 64 comprises the magnetic aperture part as a magnetoresistive part. That is, the nonmagnetic ring 64 prevents the magnetic flux from leaking between the first magnetic ring 61 and the second magnetic ring 62 (makes it difficult for the magnetic flux to flow), and the armature of the movable core with respect to the magnetic pole surface of the sub-stator 17. 14 works to increase the magnetic attractive force. The nonmagnetic ring 64 has an inner peripheral surface disposed to face the outer peripheral surface of the first magnetic ring 61 and an outer peripheral surface disposed to face the inner peripheral surface of the second magnetic ring 62. Yes. The nonmagnetic ring 64 is joined to the outer peripheral surface of the first magnetic ring 61 by all-around laser welding. Further, the nonmagnetic ring 64 is joined to the inner peripheral surface of the second magnetic ring 62 by all-around laser welding.

  As described above, the stopper 18, the intermediate housing 19, and the upper housing 20 constituting the housing of the electromagnetic actuator are connected to the entire circumferential weld P <b> 1 between the first magnetic ring 61 of the sub-stator 17 and the stopper 18, and the second magnetic ring 62 of the sub-stator 17. All-round weld P2 with the intermediate housing 19, all-round weld P3 between the first magnetic ring 61 and the nonmagnetic ring 64 of the sub-stator 17, and all-around weld between the second magnetic ring 62 and the non-magnetic ring 64 of the sub-stator 17 The stator housing space 42 is hermetically sealed with respect to the armature housing space 41 by the portion P4, the entire circumference welded portion P5 between the intermediate housing 19 and the upper housing 20, the face seals on both sides in the plate thickness direction of the intermediate spacer 33, the O-rings 52, and the like. Or it is liquid-tightly sealed.

[Operation of Example 1]
Next, the operation of the injector provided with the injector solenoid valve using the electromagnetic actuator of this embodiment will be briefly described with reference to FIGS.

  When the electromagnetic coil 12 of the electromagnetic valve of the injector is energized, an electromagnetic force is generated in the electromagnet composed of the electromagnetic coil 12 and the fixed core (main stator 16 and sub-stator 17). The armature 14 of the movable core is attracted to the magnetic pole surface side of the sub-stator 17 by the electromagnetic force of the electromagnet. Then, the armature 14 moves in a direction approaching the magnetic pole surface of the sub-stator 17 (one side in the axial direction), and the armature 14 contacts the lift restricting surface of the stopper 18. Thereby, the position of the armature 14 is regulated at the full lift position.

At this time, high-pressure fuel is introduced into the pressure control chamber 22 upstream of the valve 10 in the fuel flow direction from the common rail via the inlet port and the inlet-side orifice 25. Further, the inside of the fuel discharge passage 27 on the downstream side in the fuel flow direction from the valve 10 communicates with the fuel tank (low pressure side of the fuel system) via the fuel discharge passage and the outlet 28.
For this reason, since the fuel pressure is higher on the upstream side in the fuel flow direction than the valve 10 than on the downstream side in the fuel flow direction than the valve 10, the armature 14 of the movable core moves upward in the axial direction ( With the lift), the valve 10 is detached from the valve seat of the orifice plate 3 and the outlet-side orifice 26 of the orifice plate 3 is opened. Therefore, the fuel filled in the pressure control chamber 22 is transferred from the pressure control chamber 22 to the fuel flow path hole (including the outlet-side orifice 26) → the valve storage chamber → the fuel discharge passage 27 → the fuel discharge passage → the outlet 28. After that, it is returned to the fuel tank.

  As the solenoid valve itself opens, the fuel pressure in the pressure control chamber 22 (the oil pressure acting in the direction in which the nozzle needle 5 is pushed down (the valve closing direction)) decreases, and the fuel in the fuel reservoir chamber 21 is reduced. The pressure (the oil pressure acting in the direction in which the nozzle needle 5 is pushed up (the valve opening direction)) acts on the oil pressure in the pressure control chamber 22 in the biasing force of the coil spring 23 (the direction in which the nozzle needle 5 is pushed down (the valve closing direction)). (The biasing force to be applied) is greater than the resultant force. Thereby, since the nozzle needle 5 separates from the valve seat (seat surface) of the nozzle body 6, a plurality of injection holes are opened. That is, the valve body (nozzle needle 5) of the fuel injection nozzle is opened, and the high-pressure fuel accumulated in the common rail is injected and supplied into the combustion chamber of each cylinder of the engine. Therefore, fuel injection into the combustion chamber for each cylinder of the engine is started.

  When the command injection period elapses from the injection timing, energization to the electromagnetic coil 12 of the electromagnetic valve is stopped. Then, the armature 14 of the movable core is moved away from the magnetic pole surface of the sub-stator 17 by the biasing force of the coil spring 11, and the valve 10 is pressed against the valve seat of the orifice plate 3. As a result, the outlet-side orifice 26 is closed, so that the high-pressure fuel supplied from the common rail to the pressure control chamber 22 via the fuel supply passage 24 and the inlet-side orifice 25 is filled in the pressure control chamber 22. Along with this, the fuel pressure in the pressure control chamber 22 increases, and the resultant force obtained by adding the urging force of the coil spring 23 to the fuel pressure in the pressure control chamber 22 becomes larger than the fuel pressure in the fuel reservoir chamber 21. Since the nozzle needle 5 is seated on the valve seat (seat surface) of the nozzle body 6, the plurality of injection holes are closed. That is, the valve body (nozzle needle 5) of the fuel injection nozzle is closed, and fuel injection into the combustion chamber for each cylinder of the engine is completed.

[Effect of Example 1]
As described above, in the solenoid valve for an injector using the electromagnetic actuator of the present embodiment, the fixed core (particularly the main stator 16) that greatly affects the operation responsiveness in order to improve the operation responsiveness of the valve 10 and the movable core. A composite sintered magnetic material is used as the material. This composite sintered magnetic material has the advantage of less generation of eddy currents, but has the disadvantages of low strength and hardness and brittleness. Therefore, in the electromagnetic actuator of the present embodiment, the annular first and second magnetic rings 61, 62 made of soft magnetic steel so as to cover the armature side end face of the main stator 16 made of composite sintered magnetic material, and Since the sub-stator 17 having the annular non-magnetic ring 64 made of non-magnetic steel material is disposed, the armature 14 of the movable core is attracted by the electromagnetic force generated by the fixed core (main stator 16 and sub-stator 17) in the electromagnetic coil 12. Thus, even when the armature 14 of the movable core collides with the fixed core, the fixed core (main stator 16) made of the composite sintered magnetic material can be prevented from being damaged.

  The sub-stator 17 of this embodiment is installed between the armature storage space 41 and the stator storage space 42 so as to partition the internal space of the electromagnetic actuator housing into the armature storage space 41 and the stator storage space 42. Yes. Further, the first magnetic ring 61 of the sub-stator 17 is joined to the outer peripheral surface of the tip of the stopper 18 constituting the housing of the electromagnetic actuator by all-around laser welding. The second magnetic ring 62 of the sub-stator 17 is joined to the annular front end surface of the small-diameter portion of the intermediate housing 19 constituting the electromagnetic actuator housing by laser welding all around. The non-magnetic ring 64 of the sub-stator 17 is joined to the outer peripheral surface of the first magnetic ring 61 by all-around laser welding, and is joined to the inner peripheral surface of the second magnetic ring 62 by all-around laser welding. Furthermore, the large-diameter portion of the intermediate housing 19 is joined to the outer peripheral side end surface of the upper housing 20 by the entire circumference laser welding.

  The housing of the electromagnetic actuator (particularly the injector body 1) has an intermediate spacer 33 sandwiched between the annular end surface of the cylindrical portion 31 of the injector body 1 and the annular end surface of the stepped portion 32 of the flange housing 4. The close contact surface of 31 and the close contact surface of the intermediate spacer 33 are surface-sealed. Further, the intermediate spacer 33 is sandwiched between the annular end surface of the cylindrical portion 31 of the injector body 1 and the annular end surface of the stepped portion 32 of the flange housing 4, so that the contact surface of the intermediate spacer 33 and the contact surface of the flange 50 are formed. Face sealed. A synthetic rubber O-ring 52 is inserted between the upper housing 20 and the terminal 46.

  As a result, the stopper 18, the intermediate housing 19 and the upper housing 20 that constitute the housing of the electromagnetic actuator are connected to the entire circumferential weld P <b> 1 between the first magnetic ring 61 of the sub-stator 17 and the stopper 18, and the second magnetic ring 62 of the sub-stator 17. All-round weld P2 with the intermediate housing 19, all-round weld P3 between the first magnetic ring 61 and the nonmagnetic ring 64 of the sub-stator 17, and all-around weld between the second magnetic ring 62 and the non-magnetic ring 64 of the sub-stator 17 The armature housing space 41 for housing the armature 14 together with the fuel by the portion P4, the entire circumference welded portion P5 between the intermediate housing 19 and the upper housing 20, the face seals on both sides in the plate thickness direction of the intermediate spacer 33, and the O-ring 52, etc. The stator storage space 42 for storing the main stator 16 is airtight or liquid tight It is sealed.

Thereby, the airtightness of the stator storage space 42 can be ensured with respect to the armature storage space 41. Here, when a corrosive fuel is used as the fuel filled in the armature storage space 41, for example, DME fuel (dimethyl ether fuel) or CNG gas fuel (liquefied natural gas fuel) is used, or corrosive components are used. Even in the case of using the contained fuel, the airtightness of the stator housing space 42 can be ensured with respect to the armature housing space 41, so that corrosive fuel is contained in the composite sintered magnetic material constituting the main stator 16. Resin components (resin powder, etc.) and resin components (coil bobbin 13, synthetic resin (mold resin) for molding electromagnetic coil 12 and synthetic resin insulating bush 51) and rubber components accommodated in stator housing space 42 (Synthetic rubber O-ring 52 accommodated in the terminal through hole 48 communicating with the stator accommodating space 42) So as to.
Therefore, the resin component (resin powder, etc.), the resin component, and the rubber component contained in the composite sintered magnetic material constituting the main stator 16 are protected from, for example, corrosive fuel filled in the armature storage space 41. Therefore, durability of the main stator 16 made of an electromagnetic actuator, particularly a composite sintered magnetic material, can be improved.

  FIG. 5 shows a second embodiment of the present invention, and FIGS. 5A and 5B show a sub-stator (magnetic plate).

  The sub-stator 17 of the electromagnetic actuator of the present embodiment includes an annular first magnetic part (first magnetic fixed body) 71 installed so as to be in direct contact with the outer peripheral surface of the stopper 18, and a small diameter part of the intermediate housing 19. An annular second magnetic portion (second magnetic fixed body) 72 installed so as to be in direct contact with the annular end surface (annular tip surface) on the armature side, and the outer periphery of the first magnetic portion 71 and the second magnetic portion 72 An annular magnetoresistive portion (nonmagnetic fixed body) 74 is provided between the inner periphery and the inner periphery.

  The first and second magnetic parts 71 and 72 and the magnetoresistive part 74 constitute an annular magnetic plate integrated with a soft magnetic steel material. As an example of the soft magnetic steel material, this magnetic plate is composed (formed) of silicon steel in which silicon is contained in iron as in the first embodiment. In this embodiment, silicon steel (1LSS to 3LSS) having a silicon content of 1 to 3 mass is used.

  An annular recess (ring groove) 75 is formed on the armature side end face of the sub-stator (magnetic plate) 17 in a portion corresponding to the nonmagnetic ring 64 made of the nonmagnetic steel material of the first embodiment. The ring groove 75 is formed by making the plate thickness (t) of the magnetoresistive portion 74 thinner than the two first and second magnetic portions 71 and 72. The main stator side end face of the sub-stator (magnetic plate) 17, that is, the positions of the flat end faces of the first and second magnetic portions 71 and 72 and the magnetoresistive portion 74 are on the same plane.

The first magnetic part 71 is disposed on the outer side in the radial direction from the stopper 18 so as to cover the outer periphery of the stopper 18 in the vicinity of the lift restricting surface, and is joined to the outer peripheral surface of the tip of the stopper 18 by laser welding all around.
The second magnetic part 72 is joined to the annular front end surface of the intermediate housing 19 by laser welding all around.
The magnetoresistive portion 74 is a thin portion that is thinner than the two first and second magnetic portions 71 and 72. That is, the plate thickness (t) of the magnetoresistive portion 74 is thinner than the two first and second magnetic portions 71 and 72. Thereby, since the magnetoresistive part 74 comprises the thin magnetic diaphragm in the magnetic circuit, it prevents the magnetic flux from leaking between the first magnetic part 71 and the second magnetic part 72 (flowing magnetic flux). This makes it possible to increase the magnetic attractive force of the armature 14 with respect to the magnetic pole surface of the sub-stator 17.

  As described above, the sub-stator (magnetic plate) 17 of the electromagnetic actuator according to the present embodiment is formed as a single part of the sub-stator 17 with a soft magnetic steel material, and a ring corresponding to the non-magnetic ring 64 made of the non-magnetic steel material according to the first embodiment. A groove 75 is formed so that the magnetoresistive portion 74 is a thin magnetic diaphragm. As a result, the number of places where laser welding is performed all around can be reduced as compared with the first embodiment, so that the manufacturing cost of the electromagnetic actuator, particularly the manufacturing cost of the sub-stator (magnetic plate) 17 can be reduced.

  FIGS. 6 and 7 show a third embodiment of the present invention, and FIGS. 6A, 6B, and 7 show a sub-stator (magnetic + nonmagnetic plate).

Here, in the electromagnetic actuator described in Patent Document 1, the sub-stator made of a soft magnetic material is located closer to the armature side than the main stator made of a composite sintered magnetic material that has a small eddy current loss and can obtain high operation response. Therefore, there is a problem that the operation responsiveness deteriorates due to the eddy current loss of the sub-stator.
Therefore, the sub-stator (magnetic + non-magnetic plate) 17 of the electromagnetic actuator of the present embodiment is a radial first, extending straight from the inner peripheral portion (inner peripheral surface) of the sub-stator 17 to the outer peripheral portion (outer peripheral surface) of the sub-stator 17. A plurality of second slits 66 and 67 are formed, and the sub-stator 17 is divided into a plurality (16 pieces) in the circumferential direction.

  The plurality of first slits 66 of the annular sub-stator (magnetic + nonmagnetic plate) 17 constituted by the first and second magnetic rings 61 and 62 made of soft magnetic steel material and the nonmagnetic ring 64 made of nonmagnetic steel material. It is formed on the main stator side end face. The plurality of second slits 67 are formed on the armature side end face of the sub-stator (magnetic + nonmagnetic plate) 17.

  The first slit 66 and the second slit 67 are located between the two adjacent first slits 66 when the outer peripheral surface of the sub-stator 17 is viewed from the radially outer side than the sub-stator 17. The first slit 66 and the second slit 67 are alternately arranged in the sub-stator 17 at equal intervals so that the second slit 67 cut in the reverse direction is provided.

  Note that a plurality (eight) of first slits 66 are formed at predetermined intervals (equal intervals, for example, 45 ° intervals) in the circumferential direction of the sub-stator 17 on the main stator side end surface of the sub-stator 17. Further, a plurality (eight) of the second slits 67 are formed at predetermined intervals (equal intervals, for example, 45 ° intervals) in the circumferential direction of the sub-stator 17 on the armature side end surface of the sub-stator 17.

Each first slit 66 has a depth {D (S1)} that does not penetrate the sub-stator 17 in the plate thickness direction, and each second slit 67 has a depth that does not penetrate the sub-stator 17 in the plate thickness direction. {D (S2)}.
The depth {D (S1)} of each first slit 66 is at least half the plate thickness (T) of the sub-stator 17, and the depth {D (S2) of each second slit 67. } Is at least half of the plate thickness (T) of the sub-stator 17. That is, there is an overlap between the depth {D (S1)} of the first slit 66 and the depth {D (S2)} of the second slit 67 {D (S1) + D (S2)> T}.

  As described above, in the electromagnetic actuator of this embodiment, both end surfaces of the sub-stator 17 (the first and second magnetic rings 61 and 62 made of soft magnetic steel material, the nonmagnetic ring 64 made of nonmagnetic steel material, etc.) By providing first and second radial slits 66 and 67 alternately on the main stator side end face and the armature side end face), a sub-stator (magnetic + nonmagnetic plate) 17 of a type in which no slit is formed (Example 1). As compared with, the eddy current path becomes longer, so that the electric resistance of the eddy current increases, and the eddy current loss of the sub-stator 17 can be reduced.

  Further, the depth {D (S1), D (S2)} of the first and second slits 66 and 67 is set to 1/2 of the plate thickness (plate thickness: T) of the sub-stator (magnetic + nonmagnetic plate) 17. By making the above (for example, a depth of about 2/3), the circumferential magnetic section of each of the first and second magnetic rings 61 and 62 of the sub-stator (magnetic + nonmagnetic plate) 17 becomes a full circumferential magnetic path. Can be prevented. That is, a sub-stator (magnetic + non-magnetic plate) including a soft magnetic material on the armature side of the main stator 16 made of a composite sintered magnetic material that has a small eddy current loss and can obtain a high operation response. ) Even in the case of an electromagnetic valve for an injector using an electromagnetic actuator with 17 disposed, the eddy current path in the sub-stator (magnetic + nonmagnetic plate) 17 becomes long, so that the electric resistance of the eddy current increases and the electromagnetic When the drive current supplied to the coil 12 is turned off, eddy currents generated in the first and second magnetic rings 61 and 62 of the sub-stator 17 are reduced.

  Accordingly, the magnetism of the armature 14 of the movable core by the fixed core (the main stator 16 and the sub-stator 17) without increasing the outer diameter of the electromagnetic coil 12, that is, without increasing the size of the electromagnetic actuator in the coil radial direction. The suction force can be improved. Therefore, the operation responsiveness of the valve 10 of the electromagnetic valve and the armature 14 of the electromagnetic actuator can be enhanced.

  FIGS. 8 and 9 show Example 4 of the present invention, FIG. 8 is a diagram showing a sub-stator (magnetic plate), and FIG. 9 is a graph showing a magnetic attractive force waveform.

  The sub-stator (magnetic plate) 17 of the electromagnetic actuator of the present embodiment is a radial first extending straight from the inner peripheral portion (inner peripheral surface) of the first magnetic portion 71 to the outer peripheral portion (outer peripheral surface) of the first magnetic portion 71. A plurality of slits 76 are formed, and a plurality of radial second slits 77 extending straight from the inner peripheral portion (inner peripheral surface) of the second magnetic portion 72 to the outer peripheral portion (outer peripheral surface) of the second magnetic portion 72 are formed. The first and second magnetic portions 71 and 72 of the sub-stator 17 are divided into a plurality (16 pieces) in the circumferential direction. The magnetoresistive portion 74 has a thickness (t) that is thinner than the two first and second magnetic portions 71 and 72.

The plurality of first and second slits 76 and 77 are annular sub-stators (magnetic plates) made of a soft magnetic steel material in which a magnetoresistive portion 74 and a ring groove 75 are arranged between the two first and second magnetic rings 71 and 72. ) The first and second magnetic rings 71 and 72 are formed on the armature side end surfaces.
Further, each first slit 76 has a depth that does not penetrate the first magnetic ring 71 of the sub-stator 17 in the plate thickness direction, and each second slit 77 passes the second magnetic ring 72 of the sub-stator 17 to its plate. The depth does not penetrate in the thickness direction.
The depth of each first slit 76 is at least half the plate thickness (T) of the sub-stator 17 and equal to or greater than the depth of the ring groove 75.

  As described above, in the electromagnetic actuator of the present embodiment, the annular sub-stator 17 made of a soft magnetic steel material in which the magnetoresistive portion 74 and the ring groove 75 are disposed between the two first and second magnetic rings 71 and 72. By providing radial first and second slits 76 and 77 on the armature side end surfaces of the first and second magnetic portions 71 and 72, a sub-stator (magnetic plate) of a type in which no slit is formed (Example 2). Since the eddy current path is longer than that of the eddy current 17, the eddy current electrical resistance is increased, and the eddy current loss of the sub-stator 17 can be reduced.

  Further, the depth of the first and second slits 76 and 77 is ½ or more (for example, a depth of about 2/3) of the plate thickness (plate thickness: T) of the sub-stator (magnetic plate) 17, and By setting the depth equal to or greater than the depth of the ring groove 75, it is possible to prevent the circumferential direction of the sub-stator 17 from becoming a full circumference magnetic path. In other words, an electromagnetic actuator in which a sub-stator (magnetic plate) 17 made of a soft magnetic material is arranged on the armature side of the main stator 16 made of a composite sintered magnetic material that has a small eddy current loss and can obtain high operation responsiveness. Even in the case of an electromagnetic valve for an injector using the eddy current, the eddy current path in the sub-stator (magnetic plate) 17 becomes longer, so that the electric resistance of the eddy current increases and the drive current supplied to the electromagnetic coil 12 is turned off. When this happens, the eddy current generated in the sub-stator 17 is reduced.

Accordingly, the magnetism of the armature 14 of the movable core by the fixed core (the main stator 16 and the sub-stator 17) without increasing the outer diameter of the electromagnetic coil 12, that is, without increasing the size of the electromagnetic actuator in the coil radial direction. The suction force can be improved. Therefore, the operation responsiveness of the valve 10 of the electromagnetic valve and the armature 14 of the electromagnetic actuator can be enhanced.
Here, it can be seen from the graph of FIG. 9 that the sub-stator 17 in which the first and second slits 76 and 77 are formed as in this embodiment as compared with the sub-stator 17 of the type in which no slit is formed (embodiment 2). However, it can be seen that the magnetic attractive force of the armature 14 of the movable core by the fixed core (the main stator 16 and the sub-stator 17) is improved.

10 and 11 show a reference example to which the present invention is not applied as Example 5 , FIG. 10 is a diagram showing an electromagnetic actuator of an injector, and FIG. 11A is a sub-stator (magnetic + non-magnetic). FIG. 11B is a diagram showing a magnetic plate.

Here, the electromagnetic actuator having the plunger-type movable core described in Patent Document 1 is different from the electromagnetic actuator having the flat-plate-type movable core ( Embodiments 1 to 4 to which the present invention described above is applied ). Even with the same outer diameter, the magnetic attractive force acting between the movable core and the fixed core is small. For this reason, it is necessary to increase the outer diameter (coil diameter) of the electromagnetic coil. Further, when the fuel injection pressure to the internal combustion engine (engine) is increased, it is necessary to increase the urging force of the coil spring urging in the fully closed direction, and the suction force that overcomes the urging force of the coil spring is obtained. Therefore, it is necessary to further increase the outer diameter (coil diameter) of the electromagnetic coil.
As described above, when the outer diameter of the electromagnetic coil is made larger than the current one for the purpose of increasing the magnetic attractive force of the electromagnet composed of the electromagnetic coil and the fixed core, the size of the electromagnetic actuator (the size in the radial direction) ) Becomes too large, and there is a problem that mountability to an engine or the like deteriorates.

Therefore, even when a plunger-type movable core is adopted instead of the flat-plate-type movable core, the eddy current loss can be reduced without preventing the electromagnetic coil 12 from increasing in size and deteriorating the mountability. For the purpose of improving responsiveness, an injector solenoid valve using the electromagnetic actuator shown in FIGS. 10 and 11 is employed.
The injector of the present embodiment is a so-called direct drive type injector in which the nozzle needle is directly moved by an electromagnetic actuator in order to reduce fuel leakage. The injector includes an injector body and an electromagnetic actuator that directly drives a nozzle needle 55 that is a valve body of the injector body (see FIG. 13).
The housing of the injector body is constituted by an injector body 56 and a nozzle body 57, which are integrally coupled by tightening a retaining nut 58. The injector body 56 and the nozzle body 57 are provided with coaxial through holes, and a long nozzle needle 55 is accommodated in these through holes (see FIG. 13).

A spring accommodating space 29 for accommodating the coil spring 59 is formed in the lower portion of the injector body 56 in the figure, and the nozzle needle 55 is always urged downward in the figure under the urging force of the coil spring 59.
A distance piece 78 that forms the lower part of the spring housing space 29 is disposed at the lower end of the injector body 56 in the figure. The distance piece 78 is assembled to the lower portion of the injector body 56 by a nozzle body 57 that receives the fastening axial force of the retaining nut 58.

On the upper side of the injector body 56 in the figure, a first fuel supply passage 81 that guides the high-pressure fuel supplied from the inlet 79 to a clearance formed between the nozzle needle 55 and the through-hole, and the first fuel supply passage 81 A second fuel supply passage 82 that guides the supplied high-pressure fuel to the armature storage space 41 is formed.
The high-pressure fuel guided from the first fuel supply passage 81 to the periphery of the nozzle needle 55 is guided to the nozzle chamber 83 formed between the through hole of the nozzle body 57 and the nozzle needle 55, and the nozzle needle 55 is raised ( When full lift is performed, the fuel is ejected from the ejection holes formed in the nozzle body 57.

  The injector body and the electromagnetic actuator are configured such that the second housing 85 and the intermediate spacer 86 are sandwiched between the injector body 56 and the first housing 84, and the cylinder of the first housing 84 is disposed on the outer periphery of the cylindrical portion 87 of the injector body 56. By tightening and fixing the portion (thin wall portion) 88, the injector body and the electromagnetic actuator are integrally coupled.

  The electromagnetic actuator includes an electromagnetic coil 12 that generates an electromagnetic force (magnetic attractive force) upon receiving power supply, a plunger-type movable core (armature 14) that reciprocates the nozzle needle 55 in the axial direction thereof, and the armature 14. And a fixed core (main stator 16, sub-stator 17) disposed opposite to each other with a predetermined gap therebetween, and an internal space (armature storage space 41, stator storage) for accommodating the armature 14, main stator 16 and sub-stator 17 And a damper mechanism that damps the movement of the armature 14 using the flow resistance of the fuel filling the armature storage space 41.

  The electromagnetic actuator housing includes a bottomed cylindrical first housing 84 made of a nonmagnetic steel material that is fastened and fixed to the outer periphery of the cylindrical portion 87 of the injector body 56, and an internal space (an armature storage space 41, a stator storage space 42, etc.). The bottomed cylindrical second housing 85 made of a soft magnetic material (soft magnetic steel material) and an intermediate spacer made of a nonmagnetic material sandwiched between the annular end surface of the injector body 56 and the annular end surface of the second housing 85 86.

  The thin portion 88 of the first housing 84 is formed with an inner peripheral screw portion that is screwed into the outer peripheral screw portion of the cylindrical portion 87 of the injector body 56. A cylindrical coil housing for accommodating the electromagnetic coil 12 is provided between the inner periphery of the cylindrical portion (thick portion) 89 of the first housing 84 and the outer periphery of the cylindrical portion (thin portion) 90 of the second housing 85. A space 43 is formed. The electromagnetic coil 12 wound in the coil storage space 43 is molded with a synthetic resin (mold resin).

The fixed core of the electromagnetic actuator has a main stator 16 made of a composite sintered magnetic material, a sub-stator 17 that includes a soft magnetic steel material, and the like.
The main stator 16 is formed in a cylindrical shape so as to surround the outer periphery of a solid cylindrical pin 91 that is press-fitted and fixed to the second housing 85.
The sub-stator 17 is installed between the armature storage space 41 and the stator storage space 42 so as to partition the internal space of the second housing 85 into the armature storage space 41 and the stator storage space 42. The sub-stator 17 includes a disk-shaped magnetic part (magnetic plate) 63 made of soft magnetic steel material, an annular non-magnetic part (non-magnetic ring) 64 installed outside the magnetic plate 63 in the radial direction, and the like. It is configured.

The magnetic plate 63 is installed so as to be in direct contact with the inner peripheral surface of the nonmagnetic ring 64, and is joined to the inner peripheral surface of the nonmagnetic ring 64 by all-around laser welding.
Here, the sub-stator 17 of the present embodiment forms a plurality of radial first and second slits 66 and 67 extending straight from the central portion of the magnetic plate 63 to the outer peripheral portion (outer peripheral surface) of the magnetic plate 63, 17 is divided into a plurality (16 pieces) in the circumferential direction.
The plurality of first slits 66 are formed on the end face on the main stator side of the magnetic plate 63 made of soft magnetic steel. The plurality of second slits 67 are formed on the armature side end face of the magnetic plate 63.

The first slit 66 and the second slit 67 are formed between the two adjacent first slits 66 when the outer peripheral surface of the sub-stator 17 is viewed from the outer side in the radial direction than the magnetic plate 63 of the sub-stator 17. The first slit 66 and the second slit 67 are alternately arranged at equal intervals on the magnetic plate 63 so that the second slit 67 cut in the opposite direction with respect to 66 is provided.
Note that a plurality (eight) of first slits 66 are formed at predetermined intervals (equal intervals, for example, 45 ° intervals) in the circumferential direction of the sub-stator 17 on the end surface on the main stator side of the magnetic plate 63. A plurality (eight) of the second slits 67 are formed at predetermined intervals (equal intervals, for example, 45 ° intervals) in the circumferential direction of the sub-stator 17 on the armature side end surface of the magnetic plate 63.

  In addition, each first slit 66 has a depth {D (S1)} that does not penetrate the magnetic plate 63 of the sub-stator 17 in the thickness direction, as in the third embodiment, and each second slit 67 has This is a depth {D (S2)} that does not penetrate the magnetic plate 63 of the sub-stator 17 in the thickness direction (see FIG. 7). The depth {D (S1)} of each first slit 66 is at least half the plate thickness (T) of the sub-stator 17, and the depth {D (S2) of each second slit 67. } Is at least half of the plate thickness (T) of the sub-stator 17. That is, an overlap is provided between the depth {D (S1)} of the first slit 66 and the depth {D (S2)} of the second slit 67 (see FIG. 7).

  The nonmagnetic ring 64 is installed so as to surround the outer peripheral surface of the magnetic plate 63 in the circumferential direction. The nonmagnetic ring 64 is formed in an annular shape so as to close the plurality of first and second slits 66 and 67 that are opened on the outer peripheral surface of the magnetic plate 63. Further, the nonmagnetic ring 64 is installed so as to be in direct contact with the inner peripheral surface of the thin portion 90 of the second housing 85, and is joined to the inner peripheral surface of the thin portion 90 of the second housing 85 by laser welding all around. ing. In addition, the nonmagnetic ring 64 which comprises a magnetoresistive part similarly to Examples 1-4 is installed between the outer periphery of the magnetic plate 63, and the inner periphery of the thin part 90 of the 2nd housing 85, and the magnetic plate 63 And a magnetic restrictor that increases the magnetic attractive force of the armature 14 with respect to the magnetic pole surface of the sub-stator 17 by preventing the magnetic flux from leaking between the second housing 85 and the second housing 85.

The movable core of the electromagnetic actuator has an armature 14 made of a soft magnetic steel material and disposed opposite to the armature side end face (magnetic pole face) of the sub-stator 17 with a predetermined gap therebetween.
The armature 14 is press-fitted into the upper end of the nozzle needle 55. The armature 14 has an annular annular protrusion 92 on the end surface on the sub-stator side, which comes into contact with the end surface on the armature side of the nonmagnetic ring 64 when the armature 14 is fully lifted. The annular protrusion 92 protrudes from the outer peripheral portion of the end surface on the sub stator side of the armature 14 toward the end surface side of the armature side of the nonmagnetic ring 64 of the sub stator 17.

  Here, the armature storage space 41 is a cylindrical space between the wall surface facing the armature storage space 41 of the injector body 56 and the wall surface facing the armature storage space 41 of the sub-stator 17 (the armature side end surface). Is formed. The outer peripheral portion of the armature storage space 41 is covered by a wall surface (inner peripheral surface) facing the armature storage space 41 of the second housing 85 and the intermediate spacer 86. The armature housing space 41 is radially inward of the annular protrusion 92 and is formed between the armature-side end surface of the magnetic plate 63 of the sub-stator 17 and the sub-stator-side end surface of the armature 14. And a cylindrical outer space 94 formed radially outside the annular protrusion 92 and between the radially outer peripheral surface of the armature 14 and the inner peripheral surface of the second housing 85.

  Further, the stator storage space 42 of the present embodiment is a cylindrical space, and faces a wall surface (main stator side end surface) facing the stator storage space 42 of the sub-stator 17 and the stator storage space 42 of the second housing 85. It is formed between the wall surface (bottom surface, main stator side end surface). The inner peripheral portion of the stator storage space 42 is covered with a wall surface (outer peripheral surface) that faces the stator storage space 42 of the pin 91. The outer peripheral portion of the stator storage space 42 is covered with a wall surface (inner peripheral surface) that faces the stator storage space 42 of the second housing 85.

  As described above, the first and second housings 84 and 85 constituting the housing of the electromagnetic actuator include the magnetic plate 63 of the sub-stator 17 and the entire circumferential weld P6 of the non-magnetic ring 64, and the non-magnetic ring 64 of the sub-stator 17 and the first. The stator housing space 42 for housing the main stator 16 is hermetically or liquid-tightly sealed with respect to the armature housing space 41 for housing the armature 14 together with the fuel by the all-around welding portion P7 with the two housings 85 and the like.

  The damper mechanism of the present embodiment has a non-magnetic ring 64 of the sub-stator 17, an annular protrusion 92 of the armature 14, fuel that fills the armature storage space 41, and a clearance 95 that connects the inner space 93 and the outer space 94. Yes. The clearance 95 is formed between the armature side end surface of the nonmagnetic ring 64 of the sub stator 17 and the sub stator side end surface (uppermost surface) of the annular protrusion 92 of the armature 14.

  As a result, when the armature 14 is fully lifted, fuel that fills the inner space 93 just before the armature 14 reaches the full lift position is formed between the nonmagnetic ring 64 of the sub-stator 17 and the annular protrusion 92 of the armature 14. The movement of the armature 14 becomes dull due to the flow resistance force (oil tight damper action) of the fuel that is generated when the air flows through the clearance 95 and flows into the outer space 94 side. As a result, the collision speed at which the annular protrusion 92 of the armature 14 collides with the nonmagnetic ring 64 of the sub-stator 17 becomes slow, so that bounce of the armature 14 can be suppressed.

  As described above, in the electromagnetic actuator of the present embodiment, both end surfaces (the main stator side end surface and the armature side end surface) of the sub-stator 17 constituted by the magnetic plate 63 made of soft magnetic steel material and the nonmagnetic ring 64 made of nonmagnetic steel material. ) Are alternately provided with first and second radial slits 66 and 67, so that the path of eddy current is compared to the sub-stator (magnetic + nonmagnetic plate) 17 of the type (Example 1) in which no slit is formed. Therefore, the electric resistance of the eddy current is increased, and the eddy current loss of the sub-stator 17 can be reduced.

  Further, the depth {D (S1), D (S2)} of the first and second slits 66 and 67 is set to 1/2 of the plate thickness (plate thickness: T) of the sub-stator (magnetic + nonmagnetic plate) 17. With the above (for example, a depth of about 2/3), it is possible to prevent the entire circumference magnetic path in the circumferential cross section of the magnetic plate 63 of the sub-stator (magnetic + nonmagnetic plate) 17. That is, a sub-stator (magnetic + non-magnetic plate) including a soft magnetic material on the armature side of the main stator 16 made of a composite sintered magnetic material that has a small eddy current loss and can obtain a high operation response. ) Even in the case of an electromagnetic valve for an injector using an electromagnetic actuator with 17 disposed, the eddy current path in the sub-stator (magnetic + nonmagnetic plate) 17 becomes long, so that the electric resistance of the eddy current increases and the electromagnetic When the drive current supplied to the coil 12 is turned off, the eddy current generated in the magnetic plate 63 of the sub-stator 17 is reduced.

Accordingly, the magnetism of the armature 14 of the movable core by the fixed core (the main stator 16 and the sub-stator 17) without increasing the outer diameter of the electromagnetic coil 12, that is, without increasing the size of the electromagnetic actuator in the coil radial direction. The suction force can be improved. Therefore, the operation responsiveness of the valve 10 of the electromagnetic valve and the armature 14 of the electromagnetic actuator can be enhanced.
Further, even when a plunger-type armature 14 is employed instead of the flat-plate-type armature 14, an increase in the size of the electromagnetic coil 12 is prevented and eddy current loss can be reduced without deteriorating the mountability. Therefore, the operation responsiveness of the valve 10 of the electromagnetic valve and the armature 14 of the electromagnetic actuator can be improved.

[Modification]
In this embodiment, the electromagnetic actuator of the present invention is applied to an electromagnetic valve for an injector using the electromagnetic actuator. However, as long as the fuel passes inside, not only a moving body such as a valve but also a shutter or You may apply to the electromagnetic actuator which drives moving bodies, such as a door, in 2 positions. Moreover, you may employ | adopt the electromagnetic fluid control valve using the electromagnetic actuator of this invention. Electromagnetic fluid control valves that use electromagnetic actuators are electromagnetic valves that can change the position of a moving body such as a supply pump solenoid valve (fuel metering valve) or a common rail pressure reducing valve continuously or stepwise. There is an electromagnetic flow control valve with an actuator.

  In this embodiment, the fuel injection valve (injector) for an internal combustion engine is applied to a side return type injector that discharges fuel from an outlet 28 screwed into the shoulder of the injector body 1 when the solenoid valve is opened. However, the injector may be applied to a top return type injector that discharges fuel from the top return tube provided in the upper housing 20 when the electromagnetic valve is opened.

It is sectional drawing which showed the injector (Example 1). It is sectional drawing which showed the solenoid valve for injectors (Example 1). (Example 1) which is sectional drawing which showed the electromagnetic actuator. (Example 1) which is the top view which showed the substator (magnetic + nonmagnetic plate). (A), (b) is the perspective view and sectional drawing which showed the substator (magnetic plate) (Example 2). (A), (b) is the top view and perspective view which showed the substator (magnetic + nonmagnetic plate) (Example 3). (Example 3) which is the expanded view which showed the substator (magnetic + nonmagnetic plate). (Example 4) which is the perspective view which showed the substator (magnetic plate). It is the graph which showed the magnetic attraction force waveform (Example 4). (Example 5) which is sectional drawing which showed the electromagnetic actuator of the injector. (A) is the top view which showed the substator (magnetic + nonmagnetic plate), (b) is the perspective view which showed the magnetic plate (Example 5). It is the conceptual diagram which showed the composite sintered magnetic material (conventional technique). It is sectional drawing which showed the injector provided with the electromagnetic actuator (prior art). It is sectional drawing which showed the electromagnetic fuel injection valve (prior art).

Explanation of symbols

1 Injector body 10 Valve 12 Electromagnetic coil 14 Armature (movable core)
16 Main stator (fixed core)
17 Sub-stator (fixed core)
18 Stopper (housing, first metal pipe)
19 Intermediate housing (housing, second metal pipe)
20 Upper housing (housing)
41 Armature storage space (first space)
42 Stator storage space (second space)
51 Insulating bush 52 O-ring 61 First magnetic ring (first magnetic part)
62 Second magnetic ring (second magnetic part)
63 Magnetic plate (magnetic part)
64 Nonmagnetic Ring (Magnetoresistive part, Nonmagnetic part)
66 1st slit 67 2nd slit 71 1st magnetic part 72 2nd magnetic part 74 Magnetoresistance part 76 1st slit 77 2nd slit 92 Armature annular projection 93 Inner space 94 Outer space 95 Clearance P1 All-around weld P2 All Circumferential weld P3 Full circumference weld P4 Full circumference weld P5 Full circumference weld P6 Full circumference weld P7 Full circumference weld

Claims (9)

(A) a movable core that drives the moving body;
(B) a fixed core disposed opposite to the movable core;
(C) a housing having an internal space for accommodating the movable core and the fixed core;
(D) An electromagnetic actuator comprising a coil that is held inside the housing and receives a power supply to generate a magnetic attractive force between the movable core and the fixed core.
The fixed core is a main stator formed of a composite magnetic material obtained by solidifying metal powder and resin powder, and a sub-stator configured to include a soft magnetic material that is disposed to face the movable core side end surface of the main stator. Have
The Sabusuteta is between internal space of said housing, said a between the first air for accommodating the movable core so as to partition into the second space for accommodating the main stator, and the first space and the second space It is installed in the middle
The housing covers the entire inner periphery of the main stator so as to cover the entire outer periphery of the main stator, and a bottomed cylindrical first metal pipe disposed radially inside the main stator. It has a cylindrical second metal pipe disposed on the outer side in the radial direction than the main stator,
The first metal pipe is formed of a non-magnetic material, and an open end side facing the movable core is configured as a stopper that regulates a full lift position of the movable core,
The sub-stator has an annular first magnetic part installed so as to contact the first metal pipe, and an annular second magnetic part installed so as to contact the second metal pipe,
The first magnetic part is joined to the first metal pipe by all-around welding, and the second magnetic part is joined to the second metal pipe by all-around welding,
The electromagnetic actuator, wherein the housing is hermetically or liquid-tightly sealed with respect to the first space by a welded portion with the sub-stator. The electromagnetic actuator according to claim 1,
The sub-stator has a magnetoresistive portion formed of a nonmagnetic material between the outer periphery of the first magnetic portion and the inner periphery of the second magnetic portion,
2. The electromagnetic actuator according to claim 1, wherein the magnetoresistive part is joined to the first magnetic part by all-around welding, and is joined to the second magnetic part by all-around welding . The electromagnetic actuator according to claim 1 ,
The sub-stator has a magnetoresistive portion formed of a soft magnetic material between the outer periphery of the first magnetic portion and the inner periphery of the second magnetic portion,
2. The electromagnetic actuator according to claim 1, wherein the magnetoresistive portion is a thin portion that is thinner than the first magnetic portion and the second magnetic portion . The electromagnetic actuator according to claim 2 or請 Motomeko 3,
The movable core has an armature disposed opposite to the sub-stator with a gap therebetween,
A plurality of radial first slits extending from the inner peripheral portion of the sub-stator to the outer peripheral portion of the sub-stator are formed on the main stator side end surface of the sub-stator,
An electromagnetic actuator , wherein a plurality of radial second slits extending from an inner peripheral portion of the sub-stator to an outer peripheral portion of the sub-stator are formed on an armature side end surface of the sub-stator . The electromagnetic actuator according to claim 4, wherein
The first slit and the second slit are cut in opposite directions with respect to the first slit between the two adjacent first slits when the sub stator is viewed from a radially outer side than the sub stator. The electromagnetic actuator is characterized in that the first slit and the second slit are alternately installed in the sub-stator so that the second slit in which is inserted is provided . The electromagnetic actuator according to claim 4 or 5 ,
The first slit has a depth that does not penetrate the sub-stator in the plate thickness direction;
The second slit has a depth that does not penetrate the sub-stator in its plate thickness direction,
The depth of the first slit is at least half the plate thickness of the sub-stator,
The electromagnetic actuator according to claim 1, wherein a depth of the second slit is at least half of a thickness of the sub-stator . The electromagnetic actuator according to claim 2 or 3 ,
The movable core has an armature disposed opposite to the sub-stator with a gap therebetween,
An electromagnetic actuator, wherein a plurality of radial slits extending from an inner peripheral portion of the sub-stator to an outer peripheral portion of the sub-stator are formed on an armature side end surface of the sub-stator. The electromagnetic actuator according to claim 7, wherein
The slit is a depth that does not penetrate the sub-stator in its plate thickness direction,
The electromagnetic actuator according to claim 1, wherein a depth of the slit is at least half of a plate thickness of the sub-stator . The electromagnetic actuator according to any one of claims 1 to 8 ,
The electromagnetic actuator according to claim 1, wherein the moving body is a valve of an electromagnetic valve for an injector .

Images