JP2001085224A - Core for solenoid-operated valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently flow magnetic fluxes that circulates in the inner and outer peripheries of the electromagnetic coil of a core for solenoid-operated valve used in a solenoid-operated valve and, in to reduce the cost of the core. SOLUTION: The constitution of an upper core 34 or a lower core 42 mounted on an solenoid-operated valve device 10 is decided from two relational expressions for making magnetic fluxes circulate efficiently. The expressions are found from the magnetization characteristics of a soft magnetic composite material and grain-oriented silicon steel and make magnetic fluxes generated by the upper coil 34 and lower coil 40 circulate without loss. One expression defines the area ratio between an internal core 50 and an external core 55 and the other expression defines the joining angles between the internal core 50 and a base-section core 60, and between the external core 55 and the base- section core 60. In addition, the costs of the cores 34 and 42 are reduced by forming the base-section core 60 in a simple structure by using SMC green compact material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a core for an electromagnetically driven valve, and more particularly to a core used as a component of an electromagnetically driven valve device constituting an intake valve or an exhaust valve of an internal combustion engine.

[0002]

2. Description of the Related Art In recent years, an electromagnetically driven intake valve or an electromagnetically driven exhaust valve capable of freely changing a working angle and a lift amount have been studied and developed. However, there are many issues to be solved, such as seating noise, valve operation reliability, power consumption, and cost.

An electromagnetically driven supply / exhaust valve actuator is first required to have a sufficient electromagnetic force with respect to changes in operating conditions such as fluctuations in exhaust cylinder pressure, and to be able to mount four valves per cylinder.

As a conventional technique for obtaining a sufficient electromagnetic force, for example, as disclosed in Japanese Patent Application Laid-Open No. H11-126715, a core for an armature is formed by laminating a plurality of thin pieces made of a magnetic material. Are known. In the above-mentioned conventional core, a plurality of thin plate pieces are laminated radially from the center of the core. Each thin plate is provided with an insulating coating on its side. Further, each thin plate is provided with a notch for forming an annular coil groove in the core.

[0005] An electromagnetic coil is accommodated in the coil groove of the core. When an exciting current is supplied to the electromagnetic coil, a magnetic flux is generated that returns between the inner and outer circumferences of the electromagnetic coil. The insulating coating provided on the thin plate piece prevents the penetration of magnetic flux. Therefore, a large amount of magnetic flux circulating in the inner and outer peripheries of the electromagnetic coil returns to the inner and outer peripheries of the electromagnetic coil mainly through the individual thin plate pieces without being exchanged in large amounts between the adjacent thin plate pieces.

When the density of the magnetic flux flowing through the core increases or decreases, an eddy current is generated by electromagnetic induction, which hinders the change. In order to provide the electromagnetically driven valve with excellent responsiveness, it is desirable that the eddy current that hinders the change in magnetic flux density disappears at an early stage. It is known that the eddy current disappears as soon as it is generated inside a thin magnetic plate. According to the above-mentioned conventional core, the eddy current can be eliminated at an early stage, and excellent responsiveness can be given to the electromagnetically driven valve.

[0007] In order to obtain excellent power consumption characteristics in an electromagnetically driven valve, it is desirable that the core efficiently circulates a large magnetic flux. Leads to the method of distributing.

A directional silicon steel sheet is a steel sheet having different magnetization characteristics depending on the direction of an applied magnetic field. More specifically, for a magnetic field directed in a predetermined direction, a magnetic flux is more easily circulated than for a normal silicon steel sheet, while for a magnetic field directed to another direction, compared to a normal silicon steel sheet. It is a steel sheet that does not allow magnetic flux to flow easily. Hereinafter, the direction in which the directional silicon steel sheet allows the magnetic flux to flow easily is referred to as an easy magnetization direction, and the direction in which the magnetic flux is difficult to flow is referred to as a difficult magnetization direction.

[0009] The magnetic flux flowing through the above-mentioned conventional core travels mainly in the axial direction of the core on the inner peripheral side and the outer peripheral side of the coil groove.
Therefore, if the plurality of thin plate pieces constituting the core are formed of a directional silicon steel sheet so that the axial direction of the core and the easy magnetization direction coincide with each other, a large amount of the core can be efficiently generated with respect to the magnetic field generated by the electromagnetic coil. The magnetic flux can flow. Further, in the lower part of the coil groove, since the magnetic flux flowing through the core proceeds in the radial direction of the core, the core is made of a directional silicon steel plate so that the axial direction of the core and the easy magnetization direction coincide.

[0010] By using the above structure, the magnetic flux generated in the electromagnetic coil can be efficiently returned to the electromagnetic core in the prior art.

[0011]

However, in the above-mentioned prior art, since the grain-oriented silicon steel sheet must be processed into a complicated structure as described above, the production cost becomes a problem.

The present invention has been made in view of the above points, and a first object of the present invention is to provide a core for an electromagnetically driven valve which reduces manufacturing cost and formability.

It is a second object of the present invention to realize a core having a structure different from that of the prior art, in which when an electromagnetic coil generates a magnetic field, a core that efficiently circulates a magnetic flux flowing back and forth between the inner and outer circumferences of the electromagnetic coil. It is in.

A third object of the present invention is to provide an electromagnetically driven valve device which has a sufficient electromagnetic force and can be mounted and arranged.

[0015]

A first object of the present invention is to provide an electromagnetically driven valve core for use in an electromagnetically driven valve, wherein the coil groove is formed on an inner peripheral side of the coil groove. A directional soft magnetic plate extending along the outer peripheral side, and an inner peripheral side of the coil groove, a bottom surface side of the coil groove where the directional silicon steel plate disposed on the outer peripheral side hardly passes a magnetic field. And a soft magnetic composite material disposed on the substrate.

A second object of the present invention is to provide an electromagnetically driven valve core for use in an electromagnetically driven valve, wherein the inner core has a plurality of cores radially arranged from the center of the electromagnetic core. And the first soft magnetic composite material disposed in a gap between the plurality of first laminated members, and the outer core is disposed radially from a center of the electromagnetic core. And a second soft magnetic composite material disposed in a gap between the plurality of second laminated members and the plurality of second laminated members, and the first laminated member includes a plurality of steel plates. The second laminated member is achieved by including a plurality of steel plates.

According to a third aspect of the present invention, there is provided a core for an electromagnetically driven valve used for an electromagnetically driven valve, wherein the laminated member has a direction in which the laminated member extends in a direction in which a magnetic flux easily flows. The soft magnetic material, which is formed of a steel plate and is disposed on an outer peripheral portion, or the laminated material disposed on an inner peripheral portion, and the soft magnetic disposed to connect the inner peripheral portion and the outer peripheral portion. The angle of the joint surface with the composite material is achieved by being determined by the ratio obtained from the relationship of the magnetic flux density between the laminated material and the soft magnetic composite material.

Furthermore, in the electromagnetically driven valve core used in the electromagnetically driven valve, the area of the outer peripheral portion of the electromagnetic core and the electromagnetic core on the surface that collides with the armature are set forth in claim 5 and 6. Is achieved by the electromagnetically driven valve core determined from the relationship of the magnetic flux density between the laminated material and the soft magnetic composite material.

A third object of the present invention is to use the electromagnetically driven valve core according to any one of claims 1 to 6 for an electromagnetically driven intake valve and / or an electromagnetically driven exhaust valve. This is achieved by:

In the present invention, the electromagnetically driven valve core has a laminated member on each of the inner peripheral side and the outer peripheral side of the coil groove. For this reason, the electromagnetically driven valve core efficiently circulates the magnetic flux with respect to the magnetic field directed from the inner peripheral side to the outer peripheral side of the coil groove or the magnetic field directed in the opposite direction. However, since the magnetic field generated by the coil is in the radial direction of the coil on the bottom surface side of the coil groove, the magnetic field is difficult to pass through the directional magnetic material. Therefore, by arranging a soft magnetic composite material on the bottom surface side of the coil groove, the magnetic flux can be efficiently circulated with respect to the magnetic field around the coil.

The core has a structure in which the number of magnetic fluxes flowing on the inner peripheral side and the number of magnetic fluxes flowing on the outer peripheral side of the coil groove are substantially the same. Further, the joining angle between the soft magnetic composite material on the bottom surface and the laminated members on the inner and outer peripheral sides is determined from the magnetization characteristics of the soft magnetic composite material and the laminated members. A soft magnetic composite material is used on the bottom side of the coil.
By using the two structures, the number of magnetic fluxes flowing back through the electromagnetic core can be kept almost constant inside the electromagnetic core. This makes it possible to efficiently return the magnetic flux generated by the electromagnetic coil inside the electromagnetic core. Further, since the structure does not require complicated processing on the bottom of the coil, it is possible to provide a core for an electromagnetically driven valve which is lower in cost than the conventional technology.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of an electromagnetically driven valve device 10 having an electromagnetically driven valve core according to an embodiment of the present invention. The electromagnetically driven valve 10 has a valve body 12. The valve body 12 constitutes an intake / exhaust valve of the internal combustion engine. Valve body 12
Is disposed on the cylinder head 13 so as to be exposed in the combustion chamber of the internal combustion engine. Internal combustion engine cylinder head 1
3 is provided with an intake port 14. The intake port 14 is brought into a conductive state by being separated from the valve seat 11 with respect to the valve body 12, and is shut off by the valve body 12 sitting on the valve seat 11.

A valve shaft 15 is fixed to the valve body 12. The valve shaft 15 is held slidably in the axial direction by a valve guide 16. The valve guide 16 is supported by the cylinder head 13. An armature shaft 20 is provided above the valve shaft 15. Valve stem 1
The lower retainer 21 is fixed to the upper end of the fifth retainer 5.
Lower spring 2 is provided between lower retainer 21 and lower spring stopper 17 fixed to cylinder head 13.
2 are provided. The lower spring 22 urges the lower retainer 21, that is, the armature shaft 20 and the valve body 12 upward in FIG.

An upper retainer 24 is connected above the lower retainer 21. An upper spring 26 is provided on the upper retainer 24. The upper spring 26 urges the retainer 24, that is, the armature shaft 20 and the valve body 12 downward in FIG. An upper stopper 18 is fixed above the upper spring 26, and the upper spring 26 is disposed between the upper stopper 18 and the upper retainer 24.

A cylindrical armature 30 is joined to the armature shaft 20. Conventionally, a rectangular armature has been known. However, in the case of a rectangular armature, the rotation of the valve caused by the surge of the valve spring interferes with the housing. The frictional force at the time of this interference causes disturbance in the valve seating control. Further, in the case of a rectangular shape, the rotation of the valve is restricted, so that the valve seat collides with the valve seat, causing uneven wear. Therefore, a cylindrical armature is desirable also for maintaining the airtightness of the valve. In the present embodiment, the armature 30 is
It is composed of a cylindrical member made of a magnetic material.
Above the armature 30, a first electromagnet 32 is provided. The first electromagnet 32 includes an upper coil 34 and an upper core 36. A second electromagnet 38 is provided below the armature 30. The second electromagnet 38 includes a lower coil 40 and a lower core 42.

The upper core 36 and the lower core 42 slidably hold the armature shaft 20 at their central portions. The upper core 36 and the lower core 42
Are provided with coil grooves 43, 44 at positions surrounding the armature shaft 20, respectively. Upper coil 34
And the lower coil 42 are respectively provided with coil grooves 43, 4
4 is housed inside.

In this embodiment, the electromagnetically driven valve 10 is characterized by the structure of the upper core 36 and the lower core 42. More specifically, it is characterized in that the upper core 36 or the lower core 42 has a structure in which a magnetic flux flows at a high rate with respect to the magnetic field generated by the upper coil 34 or the lower coil 40, respectively. In addition, the characteristic part will be described later in detail.

The first electromagnet 32 and the second electromagnet 38
It is held by the outer cylinder 45 so that a predetermined interval is secured between them. Hereinafter, the operation of the electromagnetically driven valve 10 will be described. In the electromagnetically driven valve 10, by supplying an exciting current to the upper coil 34, the upper coil 3
4 can be generated. The magnetic flux circulating inside and outside the upper coil 34 is generated by the upper core 3
6 and the armature 30.
At this time, an electromagnetic force is generated between the armature 30 and the first electromagnet 32 to draw the armature 30 toward the first electromagnet 32.

Therefore, according to the electromagnetically driven valve 10, by supplying an appropriate exciting current to the upper coil 34, the armature 30, the armature shaft 20, and the valve 1
2 and the like can be displaced to the first electromagnet 32 side. The armature shaft 20 can be displaced toward the first electromagnet 32 until the armature 30 contacts the upper core 36. The armature 30 is the upper core 3 of the valve body 12.
In a situation where the intake port 14 contacts the intake port 6, the intake port 14 is closed. Therefore, according to the electromagnetically driven valve 10, the upper coil 34
By supplying an appropriate exciting current to the valve body 12, the valve body 12 can be brought into the fully closed state.

When the valve element 12 is maintained in the fully closed state, the upper spring 26 and the lower spring 22
Biases the armature shaft 20 toward the neutral position. When the supply of the exciting current to the upper coil 34 is stopped in such a situation, the armature shaft 20 is thereafter displaced in the valve opening direction according to the spring force of the upper spring 26 and the lower spring 22.

According to the electromagnetically driven valve 10, the lower coil 40
By supplying an exciting current to the lower coil 40, it is possible to generate a magnetic flux that returns inside and outside the lower coil 40. Lower coil 4
The magnetic flux circulating inside and outside the zero flows through a path including the lower core 42 and the armature 30. At this time, an electromagnetic force is generated between the armature 30 and the second electromagnet 38 to draw the armature 30 toward the second electromagnet 38. Therefore, according to the electromagnetically driven valve 10, the supply of the excitation current to the upper coil 34 is stopped, and then the excitation current is supplied to the lower coil 40 at an appropriate timing.
The armature shaft 20 can be displaced until 0 contacts the second electromagnet 38.

The valve element 12 is fully opened when the armature 30 contacts the second electromagnet 38. Therefore, according to the electromagnetically driven valve 10, after the supply of the exciting current to the upper coil 34 is stopped, the lower coil 40
By starting the supply of the exciting current to the valve body 12, the valve body 12 can be changed from the fully closed state to the fully open state. Valve body 12
When the supply of the exciting current to the lower coil 40 is stopped after changing to the fully open state, the valve body 12 is displaced toward the fully closed position by being urged by the upper spring 26 and the lower spring 22. start. Thereafter, when the exciting current is repeatedly supplied to the upper coil 34 and the lower coil 40 at an appropriate timing, the valve element 12 can be opened and closed.

The density of the magnetic flux flowing through the upper core 36 or the lower core 42 changes rapidly immediately after the supply of the exciting current to the upper coil 34 or the lower coil 40 is started and immediately after the supply of the exciting current is stopped. When the density of the magnetic flux flowing through the upper core 36 or the lower core 42 changes, an eddy current is generated in the upper core 36 or the lower core 42 so as to interfere with the magnetic flux and return.

In the system of the present embodiment, the upper core 36 is used to open and close the valve body 12 with excellent responsiveness.
Alternatively, it is desirable that the magnetic flux density be increased or decreased immediately after the supply of the exciting current to the lower core 42 is stopped. For this reason, it is necessary to quickly eliminate the eddy current that hinders the change in the magnetic flux density.

In order to ensure excellent power saving in the electromagnetically driven valve 10, when a predetermined exciting current is supplied to the upper coil 34 or the lower coil 40, the upper core 36 or the lower core 42 efficiently generates a large amount of magnetic flux. Is desirably distributed.

As shown in FIG. 3, the path through which the magnetic flux flows when the armature 20 is trapped follows the arrow parallel to the axial direction of the armature shaft 20 inside the lower coil 40 in the lower core 42 and the radial direction of the armature shaft 20 at the bottom side. The armature 20 returns from the center to the outer periphery side in accordance with the arrow of FIG. The magnetic flux also returns to the upper core 36 in the same manner.

As described above, the upper core 36 and the lower core 42 need to have a characteristic of quickly eliminating the eddy current. In addition, the structure of the upper core 36 and the lower core 42 for reducing loss in the magnetic flux flow path in FIG. 3 is required as a characteristic for efficiently transmitting the magnetic flux to the magnetic field generated by the upper coil 34 or the lower coil 40. In the present embodiment, the upper core 36 or the lower core 42 has a structure realizing both of these two characteristics.

Hereinafter, the structure of the lower core 42 of this embodiment will be described in detail with reference to FIGS.

FIG. 2 is a sectional view of the lower core 42 as viewed from above. The shape of the lower core 42 constituting the second electromagnet is cylindrical, and includes an inner core 50, an outer core 55, a coil groove 44 for accommodating an electromagnetic coil, and a base core 60.

The inner core 50 is composed of a first laminated member 51, an SMC compact 52 as a first soft magnetic composite material, and non-magnetic materials 56 and 57. The non-magnetic material 56 is provided in a cylindrical shape along the outer periphery of the armature shaft 20 and is provided with a gap in order to eliminate frictional resistance generated when the armature shaft 20 slides. As shown in FIGS. 3 and 4, a bearing 70 abutting on the armature body 30 is press-fitted into the gap. The non-magnetic material 57 has a cylindrical shape around the armature shaft 20, and the non-magnetic materials 56 and 57 form an outer frame of the inner core 50. First
The laminated member 51 and the SMC compact 52 are made of a non-magnetic material 56,
It fits inside 57 without gap. First laminated member 51
Is composed of a directional soft magnetic plate laminated along the circumferential direction of the non-magnetic materials 56 and 57 so that the axial direction of the armature shaft 20 is an easy magnetization direction, and an insulator for joining the directional soft magnetic plates to each other. Become. Using this as one unit, a plurality of first laminated members 51 are arranged radially from the center of the armature shaft 20. An approximately triangular prism formed in a gap between the first laminated member 51 and the adjacent first laminated member 51 is fitted with an SMC powder material 52 as a first soft magnetic composite material. The SMC compact 52 is made of iron powder and resin, and is pressed and heated simultaneously to form a desired shape.

The outer core 55 is disposed on the outer peripheral side of the inner core 50 with the coil groove 39 interposed therebetween. The lower coil 40 is accommodated in the coil groove 44. The configuration of the outer core 55 is such that the second laminated member 53 having the magnetic flux arrow 92 as an easy magnetization direction and the SMC powder material 54 as the second soft magnetic composite material
And a non-magnetic material 58. The non-magnetic material 58 is a cylindrical member provided on the outermost side of the outer core 55. The second laminated member 53 is formed of a nonmagnetic material 58 and a directional soft magnetic plate laminated along the circumferential direction of the coil groove 44, and an insulator for joining the directional soft magnetic plates to each other. The outer core 55 is connected to the second laminated member 53
Are arranged as a unit radially from the center of the armature shaft 20, and the adjacent second laminated member 53
The SMC powder material 53 as the second soft magnetic composite material is fitted in the gap between the substantially triangular prisms generated in the above. Second S
The MC powder material 53 is made of iron powder and resin, and a desired shape can be obtained by simultaneously applying heat and pressure.

In the structure of the lower core 42 described above, it is necessary to make the number of magnetic fluxes flowing through the inner core 50 and the outer core 55 substantially the same in order to efficiently return the magnetic flux.

FIG. 5 is a diagram showing the magnetic flux density with respect to the magnetic field strength of a general laminated member and a soft magnetic composite material. In FIG. 5, the vertical axis indicates the magnetic flux density, and the horizontal axis indicates the magnetic field intensity.
In the present embodiment, the magnetization characteristics of the laminated member and the soft magnetic composite material shown in FIG. 5 indicate that the inner core 50 and the outer core 55 have the inner core 50 and the inner core 50 determined from the condition of the equation (1) so that the number of recirculating magnetic fluxes is equal. The configuration of the outer core 55 is provided.

[0044]

0.7 × A _o-SMC + A _os ＋ 0.7 × A _i-SMC + A _iS (1) A indicates the area of the core, and the subscript o indicates the outer core 55, i
Denotes an inner core 50, SMC denotes an SMC compact, and S denotes a laminated material of a silicon steel plate.

The coefficient 0.7 in the equation (1) is a coefficient obtained from the magnetic flux density ratio between the SMC compact and the laminated material of the silicon steel sheet in the magnetization characteristic diagram of FIG. In this embodiment, the magnetic field intensity generated when the electromagnetically driven valve is operated is defined as a normal magnetic field region, and the magnetic flux density of the SMC compact obtained from one point in the normal magnetic field region is obtained from the same magnetic field intensity. Divided by the magnetic flux density of In the formula (1), the coefficient 0.7 obtained here is multiplied by the actual area of the SMC compact and the actual area of the laminated member is added, whereby the number of magnetic fluxes returning to the inner core 50 and the outer core 55 in a normal magnetic field is obtained. Seeking.

By equalizing the number of magnetic fluxes returning to the inner core 50 and the outer core 55 as described above, the magnetic flux returning at the time of capturing the armature shaft 20 can be efficiently circulated.

FIG. 3 shows the lower core 4 cut along the line AA in FIG.
2 is a sectional view of FIG. As shown in FIG. 2, the armature shaft 20 is provided at the center, and the inner core 50 is provided around this. In the cross-sectional view of FIG. 3, the inner core 50 includes the non-magnetic materials 56 and 57 shown in FIG.
58 and SMC compact 52 as a first soft magnetic composite material
And the SMC compact 54 as the second soft magnetic composite material. Here, in this embodiment, the SMC compact 5
2 and 54 and a powder material 5 constituting a base core 60 described later.
9 is formed by integral molding. An inner core 50 is provided inside the lower coil 42, an outer core 55 is provided outside, and
A base core 60 is provided at the bottom. The configuration of the inner core 50 and the outer core 55 is as shown in FIG. The configuration of the base core 60 is made of an SMC powder material 59 as a third soft magnetic composite material, and is fitted so as to match the shapes of the outer core 55, the inner core 50, and the lower coil 42. Steps are provided in the non-magnetic materials 56 and 58 to prevent the SMC powder material 52 from moving when the armature 30 is sucked.

FIG. 4 is a sectional view of the BB plane of FIG. 1 cut perpendicularly to the plane of the drawing. FIG. 4 shows a first laminated member 51 and a second laminated member 54 in the electromagnetic core portion. The configuration of the electromagnetic core is as shown in FIGS. However, at the bottom of the lower coil 42, the magnetic flux returns to the radial arrow of the electromagnetic core. Therefore, in the configuration of the laminated members 51 and 54 in which the arrow on the inner circumference side and the arrow on the outer circumference side of the magnetic flux are easy magnetization directions like the outer core 55 and the inner core 50, the magnetic flux can be efficiently passed through the core. Can not. Therefore, at the bottom of the lower coil 42 in which the magnetic flux flows in the radial direction, the SMC powder material 59 is used for the base core 60. by the way,
The joining surface between the inner core 50 and the bottom core 60 and the joining surface between the outer core 55 and the bottom core 60 are made of different materials, so that the number of recirculating magnetic fluxes must be substantially the same in order to efficiently return the magnetic flux. The purpose of this embodiment is to provide a core that efficiently circulates the magnetic flux. In order to achieve the purpose, the outer core 55, the base core 60, and the inner core 5 are provided.
0 and the angle between the respective joint surfaces of the base core 60 are expressed by equation (2).
Follow the angle.

[0049]

Θ = tan− ¹ (B _SMC / B _C ) (2) where θ is the inner core 50, the base core 60, and the outer core 5
5 is the joining angle between the base core 60, B _SMC is the magnetic flux density of the SMC compact, and B _C is the magnetic flux density of the laminated member.

Equation (2) is obtained by calculating S in a normal magnetic field shown in FIG.
The angle is determined from the magnetization characteristic diagram of the MC powder material and the directional soft magnetic material. Thereby, the magnetic flux generated by the lower coil 40 can be efficiently circulated on the joint surface between the base core 60 and the inner core 50 to the outer core 55.

In this embodiment, the bearing 7 of the armature 30 is used.
The structure of the upper core 36 other than 0 is the same as the structure of the lower core. However, any one of the cores may have another structure.

In this embodiment, of the core structure,
Although the SMC compacts 52, 54, 59 are integrally molded,
It may be formed separately.

Although the upper core 36 and the lower core 42 have the same structure in this embodiment, they may have different structures.

Further, in the present embodiment, 0.7 is used as the coefficient corresponding to α in claim 6 in equation (2), but the present invention is not limited to this. In short, it may be set based on the magnetic field strength of the magnetic material used for the core in the normal magnetic field.

[0055]

As described above, in this embodiment, a laminated member through which magnetic flux is easily circulated in the axial direction of the armature shaft 20 is used, and the SMC powder material 59 is disposed at the bottom of the coil. According to this structure, when a magnetic flux is generated in the electromagnetic coil housed in the coil groove, the magnetic flux can be efficiently returned to the inner and outer circumferences of the electromagnetic coil. Further, by designing the respective areas of the outer core and the inner core according to the equation (1) and designing the joint angle of the base core according to the equation (2), the magnetic flux can be more efficiently circulated. Can be. Further, the structure of the core for an electromagnetically driven valve according to the present invention does not require complicated processing, so that cost reduction can be realized.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an electromagnetically driven valve including an electromagnetically driven valve core of the present invention.

FIG. 2 is a cross-sectional view of the electromagnetically driven valve core of the present invention cut in a horizontal direction and viewed from above.

FIG. 3 is a cross-sectional view of the electromagnetically driven valve core of the present invention cut in a vertical direction so that a laminated member is exposed.

FIG. 4 is a cross-sectional view of the electromagnetically driven valve core of the present invention, which is cut in a vertical direction so that SMC powder material comes out.

FIG. 5 is a graph showing magnetization characteristics of an SMC powder material and a laminated member used for an electromagnetically driven valve core according to the present invention.

[Brief description of reference numerals]

 Reference Signs List 20 armature shaft 30 armature 34 upper coil 36 upper core 39 coil groove 40 lower coil 42 lower core 50 inner core 51 first laminated member 52 first soft magnetic composite material 53 second laminated member 54 second soft magnetic composite material 55 outer core 56, 57, 58 Non-magnetic material 60 Bottom core 70 Bearing

Claims (7)

[Claims] 1. An electromagnetic core used for an electromagnetically driven valve that attracts a circular armature by electromagnetic force, wherein the electromagnetic core has a coil groove in which an electromagnetic coil is housed,
An inner core formed inside the coil groove, an outer core formed outside the coil groove, and a base core arranged to be in contact with the inner core and the outer core; The inner core is made of a first laminated member and a first soft magnetic composite material, the outer core is made of a second laminated member and a second soft magnetic composite material, and the base core is formed of a third soft magnetic composite material. And a soft magnetic composite material. 2. The electromagnetically driven valve core according to claim 1, wherein the inner core includes a plurality of the first laminated members radially arranged from a center of the electromagnetic core, and the plurality of first laminated members. The first soft magnetic composite material disposed in a gap between the laminated members, wherein the outer core includes a plurality of the second laminated members radially disposed from a center of the electromagnetic core; A second soft magnetic composite material disposed in a gap between the plurality of second laminated members; the first laminated member including a plurality of steel plates; and the second laminated member including a plurality of steel plates. A core for an electromagnetically driven valve, comprising: 3. The electromagnetically driven valve core according to claim 2, wherein the third soft magnetic composite material and the first laminated member are provided so as to contact the outer core and the inner core. And / or an angle of a joining surface between the third soft magnetic composite material and the second laminated member has an angle determined by a relationship of a magnetic flux density between the soft magnetic composite material and the laminated material. For electromagnetically driven valves. 4. The electromagnetically driven valve core according to claim 3, wherein the magnetic flux density of the third soft magnetic composite material is B _SMC , and the magnetic flux density of the first laminated member and / or the second laminated member is when a B _C, the inner core and the angle theta of the base core, θ = tan- ¹ core electromagnetically driven valve, characterized in that which is defined as (B _SMC / B _C). 5. The electromagnetically driven valve core according to claim 1, wherein an area of an inner peripheral side of the electromagnetic core on a surface side contacting the armature and a surface side of the electromagnetic core contacting the armature. A core for an electromagnetically driven valve, wherein a relationship with an area on an outer peripheral side of the electromagnetic core is determined from a relationship between a magnetic flux density of the soft magnetic composite material and a magnetic flux density of the laminated member. 6. The electromagnetically driven valve core according to claim 5, wherein an area A _i-SMC occupied by the soft magnetic composite material in the inner core, and an area A _iS occupied by the first laminated member,
An area A _o-SMC occupied by the second soft magnetic composite material in the outer core and an area A occupied by the second laminated member
and _oS, the flux density of the soft magnetic composite material and the coefficient determined from the relationship between the magnetic flux density of the lamination members alpha has a relationship of _{α × A o-SMC + A} oS ≒ α × A i-SMC + A iS A core for an electromagnetically driven valve. 7. An electromagnetically driven valve device using the electromagnetically driven valve core according to claim 1 for an electromagnetically driven intake valve and / or an electromagnetically driven exhaust valve.