JP3458671B2 - Solenoid driven valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to an electromagnetically driven valve.
In particular, an electromagnetically driven valve suitable as a valve mechanism for an internal combustion engine
Related. [0002] 2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. Hei 4-50204
No. 8, disclosed as a valve mechanism for an internal combustion engine.
Electromagnetically driven valves are known. The above conventional electromagnetically driven valve
Has an armature fixed to the valve body. Armor
Upper and lower springs above and below the cha
Is installed. These springs are
To the neutral position. [0003] Above and below the armature, an upper core and
A lower core is provided. Upper core and lower core
Inside the upper coil and lower coil, respectively
Are arranged. The upper coil and lower coil are
Exciting current is supplied, so the inside and outside of them return
Generates a magnetic flux. When such magnetic flux is generated, the armor
Between Cha and Upper Koa, and Armature and Roaco
A magnetic force that draws the two between the
Works). Therefore, according to the conventional electromagnetically driven valve described above,
For example, apply a predetermined exciting current to the upper coil or lower coil.
Supply to change the valve to the closed or open position.
Can be placed. When the valve body is displaced to the valve closing position or the valve opening position,
Of the excitation current to the upper coil or lower coil after
When the supply is stopped, the armature and valve
A simple vibration is started by being urged by the ring. Simple vibration
Assuming that the amplitude is not attenuated,
Armature heading to displacement end (hereinafter referred to as target displacement end)
And the valve body are displaced only by the biasing force of the spring
Reach the end. However, armature and disc
The displacement is accompanied by energy loss due to sliding friction and the like. This
Armature and spring caused by spring bias
The maximum reaching position of the valve and the valve body is before the target displacement end. According to the above-mentioned conventional electromagnetically driven valve, the upper
The excitation current supply to the coil or lower coil was stopped.
Later, supply excitation current to the other coil at appropriate timing
To compensate for the energy loss due to sliding.
To displace the armature and valve to the target displacement end
be able to. Hereafter, upper coil and lower coil
When the excitation current is supplied alternately at appropriate timing,
The valve can be opened and closed. [0006] The above-mentioned conventional electromagnetically driven valve is provided outside the upper core.
Upper core or lower core around the circumference and lower core
An annular projection protruding from the end face of the armature side by a predetermined length
It has a part. The annular projection has an outer diameter smaller than that of the armature.
Thus, a slightly larger inner diameter is provided. Annular convex above
Armature is positioned from the target displacement end
The suction force acting on the armature when the armature is separated
Bottom, the suction force at the time of separation) has an annular convex portion.
It becomes larger than the case without. On the other hand, when an annular convex portion is provided
Armature is close to target displacement end
Suction force acting on the armature under the
(Referred to as attractive force) compared to the case where no annular projection is provided.
And become smaller. Therefore, according to the conventional electromagnetically driven valve described above,
If the armature approaches the target displacement end,
The suction force acting on the
You. The valve body reaches the valve opening position or the valve closing position
The armature and upper core or lower core
A collision sound is generated due to a collision or the like. This collision sound
Armature reaches target displacement end for suppression
The suction force acting on the armature at that point
Desirably not. Armature ensures target displacement
In order to displace to the end, a certain amount of suction
It is necessary to secure. Large for solenoid-operated valves
To suppress the collision sound while securing the suction force at the time of separation
During the process of the armature approaching the target displacement end,
The suction force acting on the tea may not show a sudden increase
It is profitable. According to the above-mentioned conventional electromagnetically driven valve, when the valve is opened and
The above requirements can be satisfied both when the valve is closed and when the valve is closed.
You. Therefore, according to the conventional electromagnetically driven valve described above, excellent static
You can get quiet. [0008] SUMMARY OF THE INVENTION Incidentally, in an internal combustion engine,
The load acting on the valve is always the same when the valve is open and when the valve is closed.
There is no. For example, exhaust valves have high combustion pressure remaining in the combustion chamber.
Valve is opened under the existing conditions, and the combustion pressure is discharged from the combustion chamber.
The valve closes after being closed. In this case, the exhaust valve is
Therefore, a larger load acts than when the valve is closed. The valve body of the electromagnetically driven valve is caused to reach a target displacement end.
The suction force at the time of separation that should be secured for
It changes according to the magnitude of the load acting on. Specifically
Means that a large load acts on the valve during the displacement of the valve
Is larger than when the load acting on the valve body is small.
It is necessary to secure a suction force at the time of separation. Therefore, electromagnetic drive
If the valve is used as an exhaust valve,
A large suction force at the time of separation is required as compared to when the valve is closed. As described above, the conventional electromagnetically driven valve is open.
Large suction force at separation, both when the valve is closed and when the valve is closed
, And the armature reaches the target displacement end
During the process, the suction force is gradually increased. Due to such characteristics
For example, if an exhaust valve is configured using an electromagnetically driven valve,
The valve is operated properly both when the valve is closed and when the valve is closed.
Can be However, the electromagnetically driven valve serves as an exhaust valve.
When used, large suction force at separation when the valve is closed
There is no need to generate. More specifically, an electromagnetically driven valve
If the valve is used as an exhaust valve, a proper
When the suction force is generated, regardless of the magnitude of the suction force at the time of separation
Therefore, the valve body can be properly closed. Solenoid driven valve
, Efficiently generate a large suction force when approaching
Then, as the armature approaches the target displacement end,
The suction force acting on the machea shows a sharp rise
Is advantageous. Therefore, an electromagnetically driven valve is used as an exhaust valve.
The valve element with low power consumption and proper
When closing the valve, the armature must be
(Pacoa) in the process of approaching, the suction acting on the armature
Desirably, the force shows a sharp increase. In this regard, the valve
Even when the valve is closed, the above-mentioned conventional electric power that gradually increases the suction force
Magnetically driven valves have not yet been improved in order to improve power saving characteristics.
It was to leave the earth. The present invention has been made in view of the above points.
Depending on the state of the internal combustion engine when the valve is opened and closed.
To provide an electromagnetically driven valve that exhibits appropriate operating characteristics.
aimed to. [0013] The above object is achieved by the present invention.
An armature displaced with the valve element as described in
-The elastic body provided on both sides of the armature and the armature
First and second cores disposed on the first and second sides;
First and second coils respectively housed in two cores
ComprisingFor exhaust valveIn the electromagnetically driven valve, the first and the second
And one of the second cores is a predetermined length toward the other core
With protruding projectionsFor example, one of the cores having the projections
The core for valve opening and the other core for valve closing.
The protrusion is slightly smaller than the outer diameter of the armature.
A ring-shaped convex portion having a large diameter;
The outer peripheral surface of the armature is positioned such that the armature is close to the one core.
When facing the inner peripheral surface of the projectionCharacterized by
This is achieved by an electromagnetically driven valve. [0014] [0015]BookIn the invention, the armature isFor valve openingone
If one is closer to the other,AOf the convex
Outer surfaceAnd corresponding to the convex partArmature outer surfaceAnd
opposite. According to such a configuration, the armatureFor opening a valveof
In the process of approaching the core, the armature has a large separation suction force
And the suction force acting on the armature
It shows a considerable increase. Further, according to the above configuration, the
MachahFor valve closingArmature in the process of approaching the core
A relatively small suction force acts on the
The suction force acting on the locker shows a sharp increasing tendency. Of the present invention
According to the characteristics, the armatureFor opening a valveWhen approaching the core of
Large load is applied to the valve body and the armatureValve closing
forLarge load is not applied to the valve body when approaching the core
In some cases, the valve body operates properly with low power consumption.
It becomes possible. [0016] FIG. 1 shows an embodiment of the present invention.
1 shows a sectional view of an electromagnetically driven valve 10. FIG. The electromagnetically driven valve 10
Used as an exhaust valve for a fuel engine. The electromagnetically driven valve 10 is
The cylinder head 12 is fixed. Cylinder head 1
An exhaust port 14 is formed in 2. Also,
A combustion chamber 16 of the internal combustion engine is formed below the head 12.
Have been. The electromagnetically driven valve 10 is connected to the exhaust port 14 and the combustion chamber.
16 is provided with a valve body 18 that conducts or shuts off the valve body 16. A valve shaft 20 is provided integrally with the valve body 18.
I have. A valve guide 22 is provided inside the cylinder head 12.
Are arranged. The valve shaft 20 is connected to a valve guide 22.
It is slidably held. At the upper end of the valve shaft 20,
The lower retainer 24 is fixed. Lower retainer 24
A lower spring 26 is provided at the lower part of the lower part. Lower
The spring 26 moves the lower retainer 24 in FIG.
It is biased upward. The upper end of the valve shaft 20 is connected to an armature shaft 28.
Abut. Armature shaft 28 is made of non-magnetic material
It is the member which was done. The armature shaft 28 has an armature
30 is fixed. The armature 30 is made of a magnetic material
It is a configured annular member. Above and below the armature 30
Has an upper core 32 and a lower core 34, respectively.
Have been. Upper core 32 and lower core 34 are magnetic
An annular member made of a material. Lower core 34 is ring
A convex portion 36 is provided. The annular convex portion 36 is
A ring projecting a predetermined length from the surface of No. 4 to the upper core 32 side
-Shaped part. The electromagnetically driven valve 10 of the present embodiment has an upper
Of the core 32 and the lower core 34, the lower core 34
It is characterized in that the annular convex portion 36 is formed.
You. The annular convex portion 36 has an outer diameter of the armature 30.
The diameter is slightly larger than that of. Therefore,
When the armature 30 approaches the lower core 34 sufficiently,
A shape in which the inner wall of the convex portion 36 faces the outer peripheral surface of the armature 30
A situation is formed. Thereafter, the outer peripheral surface of the armature 30 (annular
The surface facing the inner peripheral surface of the convex portion 36) is referred to as a convex portion facing surface 38.
Call it. The upper core 32 and the lower core 34 include
Housing upper coil 40 and lower coil 420 respectively
Have been. Also, the upper core 32 and the lower core 34
Are provided with bearings 44 and 46 at their central portions, respectively.
Has been established. The armature shaft 28 has bearings 44, 46
And are slidably held. Upper core 32 and
A core guide 48 is provided on the outer periphery of the lower core 34.
ing. Relative position of upper core 32 and lower core 34
Are maintained in proper relation by the core guide 48.
You. At the upper part of the upper core 32 and the lower part of the lower core 34
Has an upper case 50 and a lower case 52, respectively.
Fixed. A spring gear is provided at the upper end of the upper case 50.
The guide 54 and the adjuster bolt 56 are provided.
You. Below the spring guide 54, the applicator 5 is provided.
8 are provided. Appari Retainer 58 is an armature
It is connected to the upper end of the shaft 28. Also, the spring
The guide between the guide 54 and the ap
A pulling 60 is provided. Upper spring 60
Shows the appartage retainer 58 and the armature shaft 28 as shown in FIG.
1 downward. Armature 30
The neutral position is adjusted by the adjuster bolt 56.
You. In this embodiment, the neutral position of the armature 30 is
Adjust so that it is at the center of the upper core 32 and the lower core 34.
It is arranged. 2 to 9 together with FIG.
In the light of this, the operation of the electromagnetically driven valve 10 will be described. electromagnetic
In the drive valve 10, the upper coil 40 and the lower coil
If no exciting current is supplied to any of the
Armature 30 is in its neutral position, ie, upper core
32 and the center of the lower core 34. Armature 3
0 is maintained in the neutral position and the upper coil 40
When the exciting current is supplied, the armature 30 and the upper core
32 and the armature 30 is pulled toward the upper core 32 side.
An approaching electromagnetic force is generated. Therefore, the electromagnetically driven valve 10
According to this, an appropriate exciting current is supplied to the upper coil 40.
As a result, the armature 30 is displaced toward the upper core 32 side.
Can be The valve element 18 has an armature 30 having an upper
Before being brought into contact with the core 32, it is in a fully closed state. Therefore,
According to the magnetically driven valve 10, a suitable excitation is applied to the upper coil 40.
Supplying current to bring valve body 18 into the fully closed state
Can be. The state in which the valve element 18 is maintained in the fully closed state
The supply of the excitation current to the upper coil 40 is stopped below
And the valve body 18, the valve shaft 20, the armature shaft 28 and the arm
The matcher 30 is hereinafter referred to as an upper spring 60 and a lower spring.
1 by being urged by the spring 26.
Start to displace downward. Sliding friction is applied to the displacement of the valve element 18 and the like.
Energy loss. According to the electromagnetically driven valve 10,
By supplying an exciting current to the coil 42,
To compensate for the energy loss, the armature 30
The valve body 18 and the like can be displaced until the valve body 18 comes into contact with.
In the valve element 18, the armature 30 abuts on the lower core 34.
In this case, it is fully opened. Therefore, according to the electromagnetically driven valve 10, the upper
After the supply of the exciting current to the coil 40 is stopped,
Start supply of exciting current to lower coil 42 by imming
By doing so, the valve element 18 can be fully opened. Electric
According to the magnetically driven valve 10, the magnetic drive valve 10 is thereafter updated at appropriate timing.
Appropriate exciting current is applied to the
Properly open and close the valve element 18 by supplying
Can be. As described above, the solenoid-operated valve 10 of the present embodiment
Is the lower core of the upper core 32 and the lower core 34.
It is characterized in that only the
ing. The effects of the above features will be described below.
You. FIG. 2 shows that the predetermined current I₀Supply
Return through upper core 32 and armature 30
Flowing magnetic flux Φ_UThe flow of is shown. Magnetic flux Φ shown in FIG._UFlow of
This is because the armature 30 is largely separated from the upper core 32.
It is realized when you have. Number of turns of upper coil 40
Including N, an upper core 32 and an armature 30
Circuit (hereinafter, this magnetic circuit is referred to as an upper magnetic circuit 62).
The magnetic resistance of R_UThen, the upper magnetic circuit 62
Returning magnetic flux Φ_UCan be expressed as follows: [0026]   Φ_U= (NI₀) / R_U                              ... (1) FIG. 3 shows that the predetermined current I₀When you supply
Magnet circulating through lower core 34 and armature 30
Bundle Φ_LThe flow of is shown. Magnetic flux Φ shown in FIG._LThe flow of
-When the machine 30 is far away from the lower core 34
It is realized when. The number of turns of the lower coil 42 is N,
Magnetic resistance of magnetic circuit including armature 32 and armature 30
(Hereinafter, this magnetic circuit is referred to as a lower magnetic circuit 64)
_LThen, the magnetic flux Φ flowing back through the lower magnetic circuit 64_LIs next
It can be expressed as an equation. [0027]   Φ_L= (NI₀) / R_L                              ... (2) Magnetic resistance R of upper magnetic circuit 62_UIs the upper core 32
The air gap formed between the armature and the armature 30 is small.
It becomes a very small value. Similarly, the lower magnetic circuit 64
Magnetic resistance R_LIs between the lower core 34 and the armature 30
The smaller the air gap formed in
You. In this embodiment, the lower core 34
An annular convex portion 36 protruding toward the armature 30 is provided.
You. The annular convex portion 36 includes the armature 30 and the lower core 34.
Air gap between them, the air gap between them
Works to narrow. For this reason, the armature 30
Equally spaced from Pacoa 32 and Lower Core 34
In the case, the magnetic resistance R of the lower magnetic circuit 64_LBut upper magnet
Magnetic resistance R of air circuit 62_UIt is a small value compared to. Obedience
Therefore, in this case, the lower magnetic circuit 64
Magnetic flux Φ flowing on the road_UMagnetic flux Φ larger than_LCirculates
You. In the electromagnetically driven valve 10, an upper magnetic circuit
Magnetic flux Φ at 62_UAnd if the lower magnet
Magnetic flux Φ in the circuit 64_LArmature if it is available
30 and the upper core 32 or the lower core 34,
Suction force in the direction of narrowing the air gap of the upper magnetic circuit 62,
Or, in a direction to narrow the air gap of the lower magnetic circuit 64
Suction force acts. The above-mentioned suction force is obtained when the armature 30
Largely spaced from core 32 or lower core 34
Under the circumstances, the armature 30 is mainly pulled toward the upper core 32 side.
As an approaching force, or armor 30 lower core
It acts as a force to draw to the 34 side. In addition, the above suction
The attractive force is large when the magnetic flux flowing through the air gap to be narrowed is large.
It is a great power. For this reason, the armature 30 is
2 and equally spaced from the lower core 34, and
Excitation current flowing through upper coil 40 and lower coil 4
2 the excitation currents flowing through₀If, armor
Between the armature 30 and the lower core 34;
A larger suction force acts between the upper core 32 and the upper core 32.
Hereinafter, the armature 30 is the upper core 32 or the lower core.
Works between them in situations that are far away from 34
Suction force at separation F_FCalled. FIG. 4 shows that a predetermined current I₀
When the upper core 32 and the armature 30 are supplied.
Magnetic flux Φ flowing through_UThe flow of is shown. Magnetic flux shown in FIG.
Φ_UOf the armature 30 from the upper core 32
This is realized when the cranes are separated. Upper magnetic circuit 6
2 magnetic resistance R_UIs armature 30 and upper core 32
Smaller as the air gap formed between
Value. Further, as shown in the above equation (1), the upper
Magnetic flux Φ flowing through the magnetic circuit 62_UIs the magnetic resistance R_UBut
The smaller the value, the larger the value. Therefore, as shown in FIG.
When the armature 30 is approaching the upper core 32
Means that the two are largely separated as shown in FIG.
Large magnetic flux Φ in the upper magnetic circuit 62_UIs distributed
I do. Between the armature 30 and the upper core 32
Magnetic flux Φ transferred_UIs that armature 30 is upper core 3
Even under the situation where it is slightly away from 2, mainly armature
30 acts as a force to draw the core 30 toward the upper core 32 side.
You. For this reason, the armature 30 is pulled toward the upper core 32 side.
Armature 30 approaches upper core 32
In the process, the magnetic flux Φ almost flowing through the upper magnetic circuit 62._U
Increase in proportion to Hereinafter, armature 30 and upperco
When the armature 30 is close to the
The attraction force F when approaching the upper core 32_NCalled
You. FIG. 5 shows that a predetermined current I₀To
When supplied, it passes through the lower core 34 and the armature 30.
Magnetic flux Φ_LThe flow of is shown. Magnetic flux Φ shown in FIG._L
The armature 30 is slightly separated from the lower core 34.
It is realized when it is. The magnetism of the lower magnetic circuit 64
Resistance R_LIs formed between the armature 30 and the lower core 34
As the air gap becomes smaller, the value becomes smaller.
You. As shown in the above equation (2), the lower magnetic circuit 64
Flux Φ flowing through_LIs the magnetic resistance R_LThe smaller is the larger
Value. For this reason, as shown in FIG.
0 is approaching the lower core 34, as shown in FIG.
As compared to the case where both are greatly separated,
Large magnetic flux Φ in the air circuit 64_LIs distributed. Between the armature 30 and the lower core 34
Is between the bottom surface of the armature 30 and the top surface of the lower core 34
Air gap (hereinafter referred to as the axial air gap)
Magnetic flux through the armature
30 and the annular convex portion 36 of the lower core 34.
Air gap (hereinafter referred to as radial air gap)
Magnetic flux is also transmitted and received via the Magnets transmitted and received through an axial air gap
The bundle always draws the armature 30 to the lower core 34 side
Acts as a force. On the other hand, through the radial air gap
The magnetic flux transmitted and received is, as shown in FIG.
Armature 3 to such an extent that the inner wall of
0 and the lower core 34 are close together,
For armature 30, lower core 34
Acts in a direction (radial direction) that does not bias the side. For this reason,
Under the situation where the armature 30 and the lower core 34 are close to each other
To pull the armature 30 to the lower core 34 (proximity)
Time suction force F_N) Indicates that the magnetic flux flowing through the axial air gap is
The larger the value, the larger the value. The armature 30 has an axial air gap.
In the process of approaching the lower core 34, the displacement of the armature 30
The armature 30 becomes lower core 34 in proportion to the quantity.
The contact reaches the minimum value “0”. On the other hand, the diameter
The directional air gap is such that the armature 30 is
In the process of approaching, the lower end of the convex portion facing surface 38 is
6 when it reaches the upper end_MINReach Obedience
Therefore, the lower end of the convex facing surface 38 is the upper end of the annular convex 36.
The air gap in the axial direction_MINBecomes
Up to the radial air gap
As a result, a small state is formed. Magnetic flux Φ flowing through lower magnetic circuit 64_LIs a magnetic
Try to circulate through a channel with small air resistance. others
As the armature 30 approaches the lower core 34,
Radial air gap is larger than axial air gap
Under the circumstances, the magnetic flux Φ flowing through the lower magnetic circuit 64_LBut,
May flow through a radial air gap. This place
When the proximity suction force F_NIs the magnetic flux Φ_LRelatively small
Value. Further, in this case, the suction force at the time of approach F_NIs
-Relatively slow in the process of the armature 30 approaching the lower core 34
Show a gentle change. Therefore, in the electromagnetically driven valve 10, the armature
Proximity suction force acting between the tea 30 and the lower core 34
F_N(Hereinafter referred to as the lower suction force).
Suction force F acting between the upper core 30 and the upper core 32
_N(Hereinafter referred to as suction force at upper proximity)
Value. Also, the armature 30 approaches the lower core 34
In the process of lowering, the change in the suction force
When the upper 30 approaches the upper core 32 while the
Slower than the change that occurs in the suction force. FIG. 6 shows that a predetermined current I is applied to the upper coil 40.₀
When the upper core 32 and the armature 30 are supplied.
Magnetic flux Φ flowing through_UThe flow of is shown. Magnetic flux shown in FIG.
Φ_UArmature 30 contacts upper core 32
It is realized when you have. Magnetism of upper magnetic circuit 62
Resistance R_UThe armature 30 and the upper core 32 come into contact with each other.
The minimum value. In this case, the upper magnetic circuit
62 has an exciting current I₀Maximum magnetic flux Φ_UMINBut
While being distributed, the armature 30 and the upper core 32
The excitation current I₀Generates the maximum suction force for
You. Hereinafter, this suction force is referred to as the suction force at contact F_CCalled. FIG. 7 shows that a predetermined current I₀To
When supplied, it passes through the lower core 34 and the armature 30.
Magnetic flux Φ_LThe flow of is shown. Magnetic flux Φ shown in FIG._L
The armature 30 is in contact with the lower core 34
Is realized when Magnetic resistance R of lower magnetic circuit 64_L
Is when the armature 30 is in contact with the lower core 34
To the minimum value. In this case, the lower magnetic circuit 64 is
Magnetic current I₀Maximum magnetic flux Φ_LIs distributed. This implementation
In the example, the convex portion facing surface 38 of the armature 30 is
The minimum value G is always between the annular convex portion 36 of the_MINLess than
An upper air gap is formed. Therefore, armature 3
0 and the lower core 34 contact each other, the magnetic flux Φ_LMost of
Everything between the bottom of the armature 30 and the top of the lower core 34
Exchanged between In this case, armature 30 and lower core
34 and the exciting current I₀, Armature 3
0 and the attraction force F acting between the upper core 32_C
Attraction force F approximately equal to_CWorks. FIG. 8 is a graph showing the relationship between the stroke of the valve body 18 and the current.
The characteristics of the magnetically driven valve 10 are shown. The curve shown in FIG.
Excitation current I₀While supplying the valve body 18
The armature is displaced between the neutral position and the fully closed position.
FIG. 4 shows a suction force acting between the tea 30 and the upper core 32.
You. The curve shown in FIG.
Magnetic current I₀While the valve body 18 is in the neutral position and the fully open position.
When displaced between the armature 30 and the lower core.
34 shows a suction force acting between the suction force and the suction force. Further, as shown in FIG.
The straight line moves the valve 18 between the neutral position and the fully open position,
Or, if it is displaced between the neutral position and the fully closed position,
The upper spring 60 and the lower spring 26 emit.
Indicates the spring force. As described above, the upper coil 40 and the lower coil
Exciting current I equal to₀If supplied, separated
Time suction force F_FIs between the armature 30 and the lower core 34
In comparison with the armature and the upper core 32,
This is a large value. Also, the suction force F when approaching_NThe armati
Between the armor 30 and the lower core 34.
The value is smaller than that between the upper core 32 and the upper core 32. In addition,
Contact suction force F_COf the armature 30 and the lower core 34
Between the armature 30 and the upper core 32
It is almost equal. Therefore, as shown by the curve, the armature
The suction force acting between the upper core 30 and the upper core 32
18 is relatively small when located near the neutral position,
Increases relatively sharply as body 18 approaches the fully open position
Show a tendency to On the other hand, as shown in the curve, the armature 3
0 and the lower core 34 exert a suction force on the valve body 18.
Is relatively large when is located near the neutral position,
8 increases relatively slowly as it approaches the fully open position
Show the trend. As described above, the electromagnetically driven valve 10 is an internal combustion engine.
Used as an exhaust valve. Therefore, the electromagnetically driven valve 10
Is a valve body in a situation where a high combustion pressure remains in the combustion chamber 16.
18 after opening its combustion pressure
An attempt is made to close the valve element 18. High-pressure fuel is supplied to the combustion chamber 16.
Under the condition where the firing pressure remains, the valve element 18 is displaced in the valve opening direction.
At this time, a large load is applied to the valve element 18. Meanwhile,
When the rear valve element 18 is displaced in the valve closing direction, the rear valve element 18
The load is not so large. The electromagnetically driven valve 10 is held at the fully closed position.
The valve element 18 is provided with an exciting current to the upper coil 40.
Is stopped, the upper spring 60 and the
The valve spring is urged by the spring 26 to change the valve opening direction.
Rank. Similarly, in the electromagnetically driven valve 10, the
The held valve element 18 is provided with an exciting electric power to the lower coil 42.
After the supply of the flow is stopped, the upper spring 60 and
In the valve closing direction by being urged by the lower spring 26
Displace. The maximum attained position at the time of opening the valve, which is indicated by the symbol in FIG.
When the valve is opened, the valve element 18 is
And can be reached by being biased by the lower spring 26.
Position. In addition, the valve closing time indicated by a symbol in FIG.
When the valve is closed, the valve body 18
60 and the lower spring 26
Indicates the position to reach. When the valve element 18 is opened,
Large load is generated compared to when the valve is closed. Because of this,
The maximum position when valve is closed is higher than the maximum position when closed.
The position is biased toward the neutral point. The valve body 18 is appropriately displaced to the fully open position.
When the valve element 18 is at the maximum
Between the armature 30 and the lower core 34,
Spring force generated by the pulling 60 and the lower spring 26
Suction force superior to (spring force for urging the valve element 18 to the neutral position)
Need to occur. Curves and straight lines in FIG.
As shown in FIG.
be satisfied. Therefore, according to the electromagnetically driven valve 10, the valve
The body 18 can be appropriately displaced to the fully open position. By the way, the valve element 18 is moved to the upper core 32 side.
Stroke the same distance as the maximum reached position when the valve is open.
Between the armature 30 and the upper core 32
The acting suction force is then increased by the upper spring 60 and
Smaller than the spring force generated by the lower spring 26
Value. Therefore, the configuration of the lower core 34 is
2, the lower core 34
Does not have the annular convex portion 36, the lower coil 42
Excitation current I₀To supply the valve element 18 properly.
It cannot be displaced to the fully closed position. In this regard, electromagnetic
The drive valve 10 moves the valve body 18 to the fully closed position with low power consumption.
It has the characteristic that it can be displaced by The valve body 18 is appropriately displaced to the fully closed position.
When the valve element 18 is located at the maximum reaching position when the valve is closed,
Between the armature 30 and the upper core 32,
Spring generated by the spring 60 and the lower spring 26
Suction superior to force (spring force biasing valve element 18 to neutral position)
Force needs to be generated. In FIG.
As shown by the line, in the electromagnetically driven valve 10, the above-described requirements are satisfied.
Is satisfied. Therefore, according to the electromagnetically driven valve 10,
The valve element 18 can be properly displaced to the fully open position.
You. Incidentally, the valve element 18 of the electromagnetically driven valve 10 is
Suction acting between the armature 30 and the upper core 32
Until the valve element 18 reaches the maximum reaching position when the valve is closed.
No matter how small the value is during the period, the valve element 18 is closed.
The above conditions are met at the time of reaching the maximum
If it does, it will be properly displaced to the fully closed position. In FIG.
As shown in FIG.₀Supply
When the valve element 18 reaches the maximum position when the valve is closed.
Between the armature 30 and the upper core 32
Compared to the spring force generated by the ring 60 and the lower spring 26.
As a result, a sufficiently large suction force is generated. Therefore, electromagnetic drive
According to the valve 10, the exciting current supplied to the upper coil 40
With a predetermined value I₀Even if the value is small compared to
18 can be displaced to the fully closed position. FIG. 8 shows a curve and a curve.
And the exciting current I₀Large suction force F_NDepart
In order to produce, the structure of the upper core 32 is lower core 3
4 is more suitable than the structure of FIG. Therefore, the valve element 18 is closed.
The upper spring 6
Suction superior to spring force generated by zero and lower spring 26
In order to generate power with low power consumption,
The structure of the core 32 is more suitable than the structure of the lower core 34.
You. In the present embodiment, the power is supplied to the upper coil 40.
The exciting current is at the maximum position when the valve element 18 is closed.
The armature 30 and the upper core 32
The spring 60 and the lower spring 26 emit the spring.
Set to a value that generates a suction force that slightly exceeds the spring force
I have. Therefore, according to the electromagnetically driven valve 10, the valve element 18 is
Achieves excellent power saving characteristics when displacing to the fully closed position
be able to. During operation of the internal combustion engine, the valve body 18 is fully closed.
Or in the fully open position. Solenoid driven valve
According to 10, the valve element 18 reaches the fully closed position or the fully open position.
After the armature 30 reaches the lower core 34
Or, after reaching the upper core 32, the lower coil 42
Alternatively, supply an appropriate exciting current to the upper coil 40.
To maintain the valve element 18 in the fully closed position or the fully open position.
Can be. As described above, the armature 30 and the upper core
32, and the armature 30 and the lower core 34
During the excitation current I₀Suction at contact is almost equivalent to
Force F _COccurs. Therefore, according to the electromagnetically driven valve 10,
In addition to maintaining the valve element 18 in the fully closed position,
Excellent power saving characteristics even when maintaining the open position
Can be realized. As described above, the electromagnetically driven valve 10 of this embodiment
The characteristics are the timing when the valve element 18 opens and closes and the operating state of the internal combustion engine.
It is set in consideration of the relationship. For this reason, electromagnetic drive
According to the valve train 10, excellent power saving is achieved during operation of the internal combustion engine.
It is necessary to open and close the valve element 18 properly while realizing the characteristics.
Can be. Incidentally, in the above embodiment, the
2. The ring 60 and the lower spring 26 according to claim 1.
The “elastic body” described above includes an upper core 32 and a lower core 34.
The “first and second cores” according to claim 1,
The core 34 includes the core “one core” according to claim 1.
The upper core 32 corresponds to the “other core” according to claim 1,
The annular convex portion 36 corresponds to the “convex portion” according to claim 1.
It is equivalent. By the way, in the above embodiment, the
Although the pacoa 32 is not provided with a convex portion,
Akira is not limited to this.
A convex portion smaller than the annular convex portion 36 is provided.
May be. Next, with reference to FIG. 9, a second embodiment of the present invention.
The electromagnetically driven valve will be described. FIG. 9 shows the power supply of this embodiment.
The sectional view of the principal part of a magnetic drive valve is shown. Note that in FIG.
Note that the same components as those shown in FIG.
The description is omitted by attaching the reference numerals. The electromagnetically driven valve of this embodiment is shown in FIG.
In the configuration, the lower core 34 and the armature shaft 28
To the lower core 70 and the armature shaft 72 shown in FIG.
It is realized by changing. Lower core 70 is armature
An annular projection 74 is provided at a portion surrounding the shaft 72.
On the other hand, the armature shaft 72 has a connection with the armature 30.
In the portion, a concave portion 76 for accommodating the annular convex portion 74 is formed.
Is provided. A recess 76 is provided in the armature shaft 72.
As a result, on the inner peripheral surface of the armature 30, the convex opposing surface 78 is formed.
Is formed. The projection facing surface 78 of the armature 30
When the armature 30 and the lower core 70 are close to each other
Here, it faces the inner peripheral surface of the annular convex portion 74. Armature
The inner diameter of 30 is slightly larger than the outer diameter of annular projection 74.
Is set well. Therefore, the convex opposing surface 78 and the annular convex
A predetermined clearance is always secured between the
You. In the electromagnetically driven valve of this embodiment, the annular convex portion
74 and the convex portion opposing surface 78 are annular in the first embodiment.
It functions similarly to the convex portion 36 and the convex portion facing surface 38. Follow
Thus, according to the electromagnetically driven valve of the present embodiment, the electromagnetically driven valve of the first embodiment
As with the drive valve 10, excellent power saving during operation of the internal combustion engine
Opening and closing the valve element 18 properly while realizing force characteristics
be able to. Next, referring to FIG. 10, a third embodiment of the present invention will be described.
The electromagnetically driven valve of the embodiment will be described. FIG.
The sectional view of the important section of the electromagnetic drive valve of an example is shown. Note that FIG.
And the same parts as those shown in FIG.
Are denoted by the same reference numerals and description thereof is omitted. The electromagnetically driven valve of this embodiment is shown in FIG.
In the configuration, the lower core 34 and the armature 30 are
The lower core 80 and the armature shaft 82 shown in FIG.
It is realized by changing. The lower core 80 has its outermost periphery
The first annular projection 84 is provided on the
An annular groove 86 is provided on the inner peripheral side of the convex portion 84. 1st ring
A first protrusion facing surface 87 is formed on the inner peripheral surface of the protrusion 84.
I have. On the other hand, the armature 82 has a second
An annular projection 88 is provided. Outer peripheral surface of second annular projection 88
Is formed with a second convex portion facing surface 90. The second annular projection 88 is provided between the armature 82 and the
When the core 80 is close to the core 80, the annular groove of the lower core 80
86 and the second convex portion facing surface 90 is
The first annular projection 84 faces the inner wall,
The outer peripheral surface of the two annular convex portions 88 faces the first convex portion facing surface 87.
It is provided so that. The outer diameter of the armature 82 is
It is set slightly smaller than the outer diameter of the one annular convex portion 84.
I have. Therefore, the second annular convex portion 88 and the first convex portion facing surface 8
7, that is, the first annular convex portion 84 and the second convex portion
Predetermined clearance is always secured between facing surface 90
Is done. In the electromagnetically driven valve of this embodiment, the first annular
The convex portion 84 and the second annular convex portion 88 are the same as those in the first embodiment.
It functions in the same manner as the annular convex portion 36. In addition, the power
In the magnetically driven valve, the first convex portion facing surface 87 and the second convex portion
The facing surface 90 is the same as the convex portion facing surface 38 in the first embodiment.
Works in the same way. Therefore, according to the electromagnetically driven valve of this embodiment,
For example, similar to the electromagnetically driven valve 10 of the first embodiment, the
During operation, it achieves excellent power saving characteristics and properly
18 can be opened and closed. [0064] Incidentally, in the above embodiment,
A projection is provided to project from the mache 82 to the upper core 32 side.
The present invention is not limited to this.
Instead of the armature 82 on the upper core 32 side,
Even if a small convex portion is provided compared to the annular convex portion 88,
good. [0066] As described above, according to the present invention, the armature
IsCore for valve openingLarge load on the valve body in the process of approaching
Join and armatureCore for valve closingOver approaching
If a large load is not applied to the valve
It can be operated properly with no power consumption.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an electromagnetically driven valve according to a first embodiment of the present invention. FIG. 2 is a diagram showing a state of a magnetic flux Φ _U flowing back and forth between the inner and outer circumferences of an upper coil in a state where an armature and an upper core are separated from each other in the electromagnetically driven valve shown in FIG. 1; FIG. 3 is a diagram illustrating a state of a magnetic flux Φ _L circulating around the inner and outer peripheries of a lower coil when the armature and the lower core are separated from each other in the electromagnetically driven valve illustrated in FIG. 1; FIG. 4 is a diagram showing a state of a magnetic flux Φ _U flowing back and forth between the inner and outer circumferences of the upper coil in a situation where the armature and the upper core are close to each other in the electromagnetically driven valve shown in FIG. 1; FIG. 5 is a diagram illustrating a state of a magnetic flux Φ _L circulating between the inner and outer circumferences of the lower coil in a situation where the armature and the lower core are close to each other in the electromagnetically driven valve illustrated in FIG. 1; FIG. 6 is a diagram showing a state of a magnetic flux Φ _U flowing back and forth between the inner and outer circumferences of the upper coil in a state where the armature and the upper core are in contact with each other in the electromagnetically driven valve shown in FIG. 7 is a diagram showing a state of a magnetic flux Φ _L flowing back and forth between the inner and outer circumferences of the lower coil in a state where the armature and the lower core are in contact with each other in the electromagnetically driven valve shown in FIG. FIG. 8 is a diagram showing characteristics of the electromagnetically driven valve shown in FIG. FIG. 9 is a cross-sectional view illustrating a main part of an electromagnetically driven valve according to a second embodiment of the present invention. FIG. 10 is a sectional view illustrating a main part of an electromagnetically driven valve according to a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 10 Electromagnetic valve 30; 82 Armature 32 Upper core 34; 70; 80 Lower core 36; 74 Annular convex part 38; 78 Convex part facing surface 40 Upper coil 42 Lower coil 62 Upper magnetic circuit 64 Lower magnetic circuit 84 First annular Convex part 87 First convex part facing surface 88 Second annular convex part 90 Second convex part facing surface

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masahiko Asano 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-11-81938 (JP, A) European Patent Application Publication 793004 ( EP, A 1) (58) Field surveyed (Int. Cl. ⁷ , DB name) F01L 9/04 F16K 31/06 385 F16K 31/06 305 F02D 13/02

Claims (1)

(57) [Claim 1] An armature displaced together with a valve body, elastic bodies provided on both sides of the armature, and first and second cores provided on both sides of the armature. , First and second
An electromagnetically driven valve for an exhaust valve comprising first and second coils respectively housed in a core, wherein one of the first and second cores projects by a predetermined length toward the other core. part Bei example the one of the core having a convex portion is a core of the valve opening, the other
The other core is a valve closing core, and the protrusion is slightly larger than the outer diameter of the armature.
An annular convex portion having a large diameter, wherein the outer peripheral surface of the armature is
An electromagnetically driven valve characterized by facing an inner peripheral surface of the projection when approaching a core .