US20080042089A1 - Electromagnetically Driven Valve - Google Patents

Electromagnetically Driven Valve Download PDF

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Publication number
US20080042089A1
US20080042089A1 US11/660,655 US66065505A US2008042089A1 US 20080042089 A1 US20080042089 A1 US 20080042089A1 US 66065505 A US66065505 A US 66065505A US 2008042089 A1 US2008042089 A1 US 2008042089A1
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Prior art keywords
valve
oscillation
electromagnet
electromagnetically driven
disk
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Abandoned
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US11/660,655
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English (en)
Inventor
Takeshi Sakuragi
Yutaka Sugie
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Individual
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Individual
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
    • F01L9/21—Valve-gear or valve arrangements actuated non-mechanically by electric means actuated by solenoids
    • F01L2009/2105—Valve-gear or valve arrangements actuated non-mechanically by electric means actuated by solenoids comprising two or more coils
    • F01L2009/2109—The armature being articulated perpendicularly to the coils axes

Definitions

  • the invention relates generally to an electromagnetically driven valve. More specifically, the invention relates to a rotary driven type electromagnetically driven valve used for an internal combustion engine.
  • a conventional electromagnetically driven valve is disclosed in, for example, Japanese Patent Application Publication No. 11-350929 A.
  • Japanese Patent Application Publication No. 11-350929 A discloses a so-called parallel driven type electromagnetically driven valve intended for reliably attracting an armature to an electromagnet and realizing low electric power consumption.
  • the electromagnetically driven valve disclosed in Japanese Patent Application Publication No. 11-350929 A includes a valve stem formed integrally with a valve element.
  • the valve stem is provided with a collar-shaped armature that extends in the radius direction of the valve stem.
  • a first electromagnet and a second electromagnet are arranged with the armature interposed therebetween.
  • the electromagnetically driven valve further includes a lower spring that applies a force to the valve element in the direction in which the valve is closed, and an upper spring that applies a force to the valve element in the direction in which the valve is opened.
  • the lower spring and the upper spring are provided in series in the axial direction of the valve stem.
  • an electromagnetic force generated by the first electromagnet and the second electromagnet, and an elastic force of the lower spring and the upper spring are directly applied to the valve stem, whereby the valve stem reciprocates between the valve opening position and the valve closing position.
  • An assist magnet for generating a large amount of electromagnetic force is provided in a core forming the first electromagnet and the second electromagnet.
  • Japanese Patent Application Publication No. 04-276106 A discloses an electromagnetically driven valve intended for efficiently driving an electromagnetic valve.
  • the electromagnetically driven valve disclosed in Japanese Patent Application Publication No. 04-276106 A is a parallel driven type electromagnetically driven valve, as in the case of the electromagnetically driven valve disclosed in Japanese Patent Application Publication No. 11-350929 A.
  • the electromagnetically driven valve includes a valve mechanism which drives an electromagnetic valve by using an electromagnetic force.
  • a permanent magnet portion is provided in a yoke forming the valve mechanism.
  • a clearance is formed between the first electromagnet and the second electromagnet.
  • the armature reciprocates in the clearance while being alternately attracted to the first electromagnet and the second electromagnet.
  • the armature and each of the first electromagnet and the second electromagnet are uniformly apart from each other while the distance therebetween uniformly changes, except for the state where the valve stem is at one of the valve opening position and the valve closing position.
  • an electromagnetic force acts at a higher degree at a position at which the distance from the electromagnet is shorter. Therefore, the electromagnetically driven valve disclosed in Japanese Patent Application Publication No.
  • 11-350929 A has a problem that a sufficiently large amount of electromagnetic force cannot be applied to the armature, and, therefore, a large amount of driving force cannot be obtained. Such a problem also occurs in the parallel driven type electromagnetically driven valve disclosed in Japanese Patent Application Publication No. 04-276106 A.
  • Document FR 2 792 451 discloses an electromagnetic drive mechanism, wherein the electromagnetic drive mechanism has a flexible return section to move a valve between an open and closed position.
  • the flexible return is made up of tongue sections pivoting about an axis which act on the valve spoke transforming movements to the valve movement plane.
  • document EP 1 010 866 A2 discloses an electromagnetic actuating system having a valve member.
  • the electromagnetic actuating system includes an armature which moves with the valve member, an electromagnet which attracts the armature in a direction of movement of the valve member by being supplied with a current, and a spring which presses the armature away from the electromagnet.
  • a permanent magnet which can exert a magnetic attracting force between the armature and the electromagnet is provided.
  • a current controller supplies a release current to the electromagnet so that magnetic flux is generated in a direction opposite to a direction of magnetic flux generated by the permanent magnet when the armature is released from the electromagnet.
  • the valve member functions as an intake valve or an exhaust valve of an internal combustion engine, and the current controller controls an amount of said release current in accordance with an operating state of the internal combustion engine.
  • document DE 198 24 537 A1 discloses an electromagnetically driven device having a valve stem and that reciprocates in a direction in which the valve stem extends. Further, an oscillating member having an arm portion made of magnetic material extends from a first end and is movably supported by a supporting member. The arm is oscillated by means of an electromagnet that includes a core and a coil and forms a magnetic circuit.
  • the invention is made in light of the above-mentioned circumstances. It is, therefore, an object of the invention to provide an electromagnetically driven valve in which a sufficiently large amount of driving force can be obtained.
  • an electromagnetically driven valve including a drive valve which has a valve stem; two oscillation members being formed of a first oscillation member and a second oscillation member, which have an arm portion made of magnetic material, and which extends from a first end that is movably connected to the valve stem toward a second end that is movably supported by a supporting member, respectively; and an electromagnet.
  • the electromagnet includes a core that is provided so as to face the arm portion, and a coil that is wound around the core. The electromagnet forms two magnetic circuits which pass through the core and the arm portions when an electric current is applied to the coil for applying magnetism to the two oscillation members, respectively.
  • the electromagnetically driven valve further includes a permanent magnet which has a magnetic axis along the magnetic circuits, and which is provided so as to act on a magnetic flux that flows through the magnetic circuits.
  • the permanent magnet is disposed so as to balance out the magnetic flux that flows through the magnetic circuit acting on one of the two oscillation members, and to increase the magnetic flux that flows through the magnetic circuit acting on the other oscillation member.
  • the oscillation members are oscillated by using the second end as a supporting point due to an electromagnetic force applied from the electromagnet. An oscillation motion of the oscillation member is transmitted to the drive valve via the first end, whereby the drive valve reciprocates in the direction in which the valve stem extends.
  • a control method for an electromagnetically driven valve including a drive valve which has a valve stem and which reciprocates in a direction in which the valve stem extends; two oscillation members being formed of a first oscillation member and a second oscillation member which are movably connected to the valve stem; and an electromagnet which forms two magnetic circuits between the electromagnet and the oscillation members for applying magnetism to the two oscillation members, respectively, wherein the permanent magnet is disposed so as to balance out the magnetic flux that flows through the magnetic circuit acting on one of the two oscillation members, and to increase the magnetic flux that flows through the magnetic circuit acting on the other oscillation member.
  • the control method includes a first step in which a supply of an electric current to the electromagnet is stopped, whereby the oscillation member, which is at a first position at which the oscillation members have been oscillated as much as possible so that the drive valve is moved in a first direction, are started to be oscillated toward a second position at which the oscillation members are to be oscillated as much as possible so that the drive valve is moved in a second direction that is opposite to the first direction; and a second step which is performed after the first step is completed, and in which the supply of the electric current to the electromagnet is started before the oscillation member reaches a center position that is a midpoint between the first position and the second position.
  • the first position may be a position at which the oscillation member has been oscillated as much as possible so that the drive valve is opened
  • the second position may be a position at which the oscillation member has been oscillated as much as possible so that the drive valve is closed.
  • the first position may be a position at which the oscillation member has been oscillated as much as possible so that the drive valve is closed
  • the second position may be a position at which the oscillation member has been oscillated as much as possible so that the drive valve is opened.
  • the electromagnetically driven valve when the direction in which the magnetic flux flows in the permanent magnet matches the direction in which the magnetic flux flows through the magnetic circuit, the strength of the magnetic flux flowing through the magnetic circuit is increased. On the other hand, when the direction in which the magnetic flux flows in the permanent magnet is opposite to the direction in which the magnetic flux flows through the magnetic circuit, the strength of the magnetic flux flowing through the magnetic circuit is decreased. Accordingly, appropriately selecting the direction of an electric current applied to the coil makes it possible to control the amount of electromagnetic force applied to the oscillation member so that an oscillation motion of the oscillation member is promoted. In addition, in the invention, a method in which the drive valve is reciprocated due to the oscillation motion of the oscillation member is used as the method for driving the electromagnetically driven valve.
  • the distance between the arm portion and the electromagnet at a position near the second end movably supported by the supporting member is always shorter than the distance between the arm portion and the electromagnet at a position near the first end movably connected to the valve stem, regardless of the oscillation position of the oscillation member. Accordingly, a larger amount of electromagnetic force can be applied to the oscillation member. It is, therefore, possible to obtain a sufficiently large amount of driving force by providing the permanent magnet in the rotary driven type electromagnetically driven valve.
  • the strength of the magnetic flux flowing through the magnetic circuit is increased.
  • the direction in which the magnetic flux flows in the permanent magnet is opposite to the direction in which the magnetic flux flows through the magnetic circuit, the strength of the magnetic flux flowing through the magnetic circuit is decreased. Accordingly, it is possible to start the supply of electric current to the electromagnet before the oscillation member reaches the center position while reciprocating between the first position and the second position.
  • the permanent magnet may be provided in the core.
  • the permanent magnet may be provided between the core and the coil.
  • the electromagnetically driven valve thus configured, it is possible to avoid the situation where the core needs to be divided into two areas in order to provide the permanent magnet. As a result, the structure of the electromagnet can be simplified.
  • the permanent magnet may be embedded in the core, and the core may be divided into two areas by the permanent magnet on the magnetic circuit.
  • the electromagnetically driven valve in which a sufficiently large amount of driving force can be obtained, and the control method thereof.
  • FIG. 1 illustrates a cross sectional view of an electromagnetically driven valve according to a first embodiment of the invention
  • FIG. 2 illustrates a perspective view of an electromagnet in FIG. 1 ;
  • FIG. 3 illustrates a perspective view of a lower disk (an upper disk) in FIG. 1 ;
  • FIG. 4 illustrates a schematic view of the upper disk and the lower disk that have been oscillated as much as possible so that the valve is opened;
  • FIG. 5 illustrates a schematic view of the upper disk and the lower disk that are oscillating toward the center position from the position at which the upper disk and the lower disk have been oscillated as much as possible so that the valve is opened;
  • FIG. 6 illustrates a schematic view of the upper disk and the lower disk that are at the center position
  • FIG. 7 illustrates a schematic view of the upper disk and the lower disk that have been oscillated as much as possible so that the valve is closed;
  • FIG. 8 illustrates a schematic view of an electromagnetically driven valve according to a second embodiment of the invention.
  • FIG. 9 illustrates a schematic view of an electromagnetically driven valve according to a third embodiment of the invention.
  • FIG. 1 illustrates a cross sectional view of an electromagnetically driven valve according to a first embodiment of the invention.
  • the electromagnetically driven valve according to the first embodiment forms an engine valve (an intake valve or an exhaust valve) of an internal combustion engine such as a gasoline engine or a diesel engine.
  • an intake valve an intake valve or an exhaust valve
  • the description will be made concerning the case where the electromagnetically driven valve forms an intake valve.
  • the electromagnetically driven valve forms an exhaust valve, the same structure as that of the electromagnetically driven valve forming the intake valve is applied.
  • an electromagnetically driven valve 10 is a rotary driven type electromagnetically driven valve, and a parallel link mechanism is applied to a motion mechanism thereof.
  • the electromagnetically driven valve 10 includes a drive valve 14 having a stem 12 extending in one direction; a lower disk 20 and an upper disk 30 which are connected to the stem 12 at different positions, and which oscillates due to an electromagnetic force and an elastic force applied thereto; an open/close electromagnet 60 which generates the electromagnetic force (hereinafter, may be simply referred to as an “electromagnet 60 ”); a lower torsion bar 26 which is provided in the lower disk 20 and which applies the elastic force to the lower disk 20 ; and an upper torsion bar 36 which is provided in the upper disk 30 and which applies the elastic force to the upper disk 30 .
  • Permanent magnets 71 and 72 are embedded in the electromagnet 60 .
  • the drive valve 14 reciprocates in the direction in which the stem 12 extends (the direction shown by an arrow 103 ) due to the oscillation motion of the lower disk 20 and the upper disk 30 .
  • the drive valve 14 is provided in a cylinder head 41 in which an intake port 17 is formed.
  • a valve seat 42 is provided at a position at which the intake port 17 formed in the cylinder head 41 is communicated with a combustion chamber (not shown).
  • the drive valve 14 further includes a bell portion 13 formed at an end of the stem 12 . As the drive valve 14 reciprocates, the bell portion 13 alternately contacts the valve seat 42 and moves away from the valve seat 42 , whereby the intake port 17 is alternately closed and opened. Namely, when the stem 12 moves upward, the drive valve 14 is moved toward the valve closing position, and when the stem 12 moves downward, the drive valve 14 is moved toward the valve opening position.
  • the stem 12 is formed of a lower stem 12 m that extends from the bell portion 13 , and an upper stem 12 n that is connected to the lower stem 12 m with a lash adjuster 16 interposed between the lower stem 12 m and the upper stem 12 n .
  • the lash adjuster 16 serves a buffering member located between the upper stem 12 n and the lower stem 12 m , and is likely to shrink and unlikely to stretch.
  • the lash adjuster 16 absorbs an error in positioning of the drive valve 14 at the valve closing position, and allows the bell portion 13 to reliably contact the valve seat 42 .
  • a connection pin 12 p which protrude from the outer surface of the lower stem 12 m , is provided for the lower stem 12 m .
  • a connection pin 12 q which protrudes from the outer surface of the upper stem 12 n , is provided for the upper stem 12 n at a predetermined distance from the connection pin 12 p.
  • a valve guide 43 is provided in the cylinder head 41 so as to slidably guide the lower stem 12 m in the axial direction.
  • a stem guide 45 is provided so as to slidably guide the upper stem 12 n in the axial direction, at a position at a predetermined distance from the valve guide 43 .
  • the valve guide 43 and the stem guide 45 are made of metal material such as stainless so as to endure sliding with the stem 12 at a high speed.
  • a disk supporting base 51 is fitted on the top surface of the cylinder head 41 , at a predetermined distance from the stem 12 .
  • FIG. 2 illustrates a perspective view of the electromagnet 60 in FIG. 1 .
  • the electromagnet 60 is fitted to the disk supporting base 51 , at a position between the lower disk 20 and the upper disk 30 .
  • the electromagnet 60 is formed of an open/close coil 62 (hereinafter, may be simply referred to as a “coil 62 ”), and an open/close core 61 (hereinafter, may be simply referred to as a “core 61 ”) which has attraction surfaces 61 a and 61 b , and which is made of magnetic material.
  • the core 61 has a shaft portion 61 p extending in the direction perpendicular to the direction in which the stem 12 extends.
  • the coil 62 is provided around the shaft portion 61 p , and formed of a mono-coil (i.e., a coil formed of a piece of wire).
  • the permanent magnet 71 is provided so as to be located on the magnetic circuit 101
  • the permanent magnet 72 is provided so as to be located on the magnetic circuit 102 .
  • the core 61 is divided, by the permanent magnets 71 and 72 , into a portion 61 m including the shaft portion 61 p , and portions 61 n one of which faces the upper disk 30 and the other of which faces the lower disk 20 .
  • the permanent magnet 71 has the magnetic axis in the direction along the magnetic circuit 101 .
  • the south pole is formed in the side of the permanent magnet 71 , which is close to the portion 61 n .
  • the north pole is formed in the side of the permanent magnet 71 , which is close to the portion 61 m .
  • the permanent magnet 72 has the magnetic axis in the direction along the magnetic circuit 102 .
  • the north pole is formed in the side of the permanent magnet 72 , which is close to the portion 61 n .
  • the south pole is formed in the side of the permanent magnet 72 , which is close to the portion 61 m .
  • the magnetic flux formed in the permanent magnet 72 flows from the side close to the portion 61 m toward the side close to the portion 61 n (in the direction shown by an arrow 72 x ) due to magnetic poles.
  • the disk supporting base 51 is further provided with a valve opening permanent magnet 55 , and a valve closing permanent magnet 56 that is opposed to the valve opening permanent magnet 55 with the electromagnet 60 interposed therebetween.
  • the valve opening permanent magnet 55 has an attraction surface 55 a .
  • a space in which the lower disk 20 oscillates is defined between the attraction surface 55 a of the valve opening permanent magnet 55 and the attraction surface 61 b of the electromagnet 60 .
  • the valve closing permanent magnet 56 has an attraction surface 56 a .
  • a space in which the upper disk 30 oscillates is defined between the attraction surface 56 a of the valve closing permanent magnet 56 and the attraction surface 61 a of the electromagnet 60 .
  • FIG. 3 illustrates a perspective view of the lower disk 20 (upper disk 30 ) in FIG. 1 .
  • the lower disk 20 has a first end 22 and a second end 23 , and extends from the second end 23 toward the first end 22 in the direction that crosses the direction in which the stem 12 extends.
  • the lower disk 20 is formed of an arm portion 21 that has rectangular surfaces 21 a and 21 b and that extends from the second end 23 toward the first end 22 , and a hollow cylindrical bearing portion 28 that is formed in the second end 23 side.
  • the surface 21 a faces the attraction surface 61 b of the electromagnet 60
  • the surface 21 b faces the attraction surface 55 a of the valve opening permanent magnet 55 .
  • the magnetic circuit 102 formed by applying an electric current to the coil 62 forms a closed-loop that passes through the shaft portion 61 p of the core 61 , the permanent magnet 72 , and the arm portion 21 .
  • a notched portion 29 is formed in the arm portion 21 in the first end 22 side.
  • a long hole 24 is formed in each of wall surfaces of the notched portion 29 , which face each other.
  • a central axis 25 is defined which extends in the direction perpendicular to the direction from the first end 22 toward the second end 23 .
  • a through-hole 27 extending along the central axis 25 is formed in the bearing portion 28 .
  • the upper disk 30 has the same shape as that of the lower disk 20 .
  • a first end 32 , a second end 33 , an arm portion 31 , a surface 31 b , a surface 31 a , a notched portion 39 , and a long hole 34 , a bearing portion 38 , a through-hole 37 , and a central axis 35 are formed, which correspond to the first end 22 , the second end 23 , the arm portion 21 , the surface 21 a , the surface 21 b , the notched portion 29 , the long hole 24 , the bearing portion 28 , the through-hole 27 , and the central axis 25 in the lower disk 20 , respectively.
  • the surface 31 a faces the attraction surface 61 a of the electromagnet 60
  • the surface 31 b faces the attraction surface 56 a of the valve closing permanent magnet 56
  • the lower disk 20 and the upper disk 30 are made of soft magnetic material.
  • the magnetic circuit 101 formed by applying an electric current to the coil 62 forms a closed-loop that passes through the shaft portion 61 p of the core 61 , the permanent magnet 71 , and the arm portion 31 .
  • the first end 22 of the lower disk 20 is movably connected to the lower stem 12 m , when the connection pin 12 p is inserted into the long holes 24 .
  • the first end 32 of the upper disk 30 is movably connected to the upper stem 12 n , when the connection pin 12 q is inserted into the long holes 34 .
  • the second end 23 of the lower disk 20 is movably supported by the disk supporting base 51 via the lower torsion bar 26 inserted into the through-hole 27 .
  • the second end 33 of the upper disk 30 is movably supported by the disk supporting base 51 via the upper torsion bar 36 inserted into the through-hole 37 .
  • the drive valve 14 can be reciprocated by oscillating the lower disk 20 with respect to the central axis 25 , and the upper disk 30 with respect to the central axis 35 .
  • An elastic force is applied to the lower disk 20 by the lower torsion bar 26 in the clockwise direction around the central axis 25 .
  • An elastic force is applied to the upper disk 30 by the upper torsion bar 36 in the counterclockwise direction around the central axis 35 .
  • the lower disk 20 and the upper disk 30 are placed at the center position by the lower torsion bar 26 and the upper torsion bar 36 .
  • the center position is the midpoint between the position at which the lower disk 20 and the upper disk 30 have been oscillated as much as possible so that the valve is opened, and the position at which the lower disk 20 and the upper disk 30 have been oscillated as much as possible so that the valve is closed.
  • FIG. 4 illustrates a schematic view of the upper disk 30 and the lower disk 20 that have been oscillated as much as possible so that the valve is opened.
  • FIG. 5 illustrates a schematic view of the upper disk 30 and the lower disk 20 that are moving toward the center position from the position at which the upper disk 30 and the lower disk 20 have been oscillated as much as possible so that the valve is opened.
  • FIG. 6 illustrates a schematic view of the upper disk 30 and the lower disk 20 that are at the center position.
  • FIG. 7 illustrates the upper disk 30 and the lower disk 20 that have been oscillated as much as possible so that the valve is closed.
  • the electromagnetic force generated by the electromagnet 60 disappears.
  • the upper disk 30 and the lower disk 20 move away from the attraction surfaces 61 a and 55 a , respectively, and start to oscillate toward the center position due to the elastic force of the lower torsion bar 26 .
  • an electric current is applied to the coil 62 in the direction shown by an arrow 115 , before the lower disk 20 and the upper disk 30 reach the center position.
  • a magnetic flux flows between the core 61 and the lower disk 20 in the direction shown by an arrow 117 , and an electromagnetic force for attracting the lower disk 20 to the attraction surface 61 b of the electromagnet 60 is generated.
  • a magnetic flux flows between the core 61 and the upper disk 30 in the direction shown by an arrow 116 , and an electromagnetic force for attracting the upper disk 30 to the attraction surface 61 a of the electromagnet 60 is generated.
  • the strength of magnetic flux increases. Accordingly, the electromagnetic force for attracting the lower disk 20 to the attraction surface 61 b increases. Meanwhile, since the direction in which the magnetic flux flows between the core 61 and the upper disk 30 is opposite to the direction in which the magnetic flux formed in the permanent magnet 71 flows, the magnetic flux flowing between the core 61 and the upper disk 30 and the magnetic flux formed in the permanent magnet 71 balance each other out, and, therefore, the strength of magnetic flux is decreased. Accordingly, the electromagnetic force for attracting the upper disk 30 to the attraction surface 61 a is decreased.
  • providing the permanent magnets 71 and 72 makes it possible to increases the electromagnetic force applied in the direction in which the lower disk 20 and the upper disk 30 oscillate, and to decrease the electromagnetic force applied in the direction opposite to the direction in which the lower disk 20 and the upper disk 30 oscillate. It is, therefore, possible to increase a force for closing the drive valve 14 obtained due to the oscillation motion of the lower disk 20 and the upper disk 30 .
  • the lower disk 20 and the upper disk 30 are oscillated from the center position toward the position at which the lower disk 20 and the upper disk 30 are to be oscillated as much as possible so that the valve is closed, due to the electromagnetic force of the electromagnet 60 for attracting the lower disk 20 to the attraction surface 61 b and the magnetic force of the valve closing permanent magnet 56 for attracting the upper disk 30 to the attraction surface 56 a .
  • Providing the valve closing permanent magnet 56 makes it possible to compensate for the shortfall of the electromagnetic force, which is likely to occur particularly when the drive valve 14 is near the valve closing position. It is, therefore, possible to prevent the force for closing the drive valve 14 from decreasing.
  • an electric current is applied to the coil 62 in the direction shown by the arrow 110 , before the lower disk 20 and the upper disk 30 reach the center position.
  • a magnetic flux flows between the core 61 and the upper disk 30 in the direction shown by an arrow 111 , and an electromagnetic force for attracting the upper disk 30 to the attraction surface 61 a of the electromagnet 60 is generated.
  • a magnetic flux flows between the core 61 and the lower disk 20 in the direction shown by an arrow 112 , and an electromagnetic force for attracting the lower disk 20 to the attraction surface 61 b of the electromagnet 60 is generated.
  • the strength of magnetic flux increases. Accordingly, the electromagnetic force for attracting the upper disk 30 to the attraction surface 61 a increases. Meanwhile, since the direction in which the magnetic flux flows between the core 61 and the lower disk 20 is opposite to the direction in which the magnetic flux formed in the permanent magnet 72 flows, the magnetic flux flowing between the core 61 and the lower disk 20 and the magnetic flux formed in the permanent magnet 72 balance each other out, and, therefore, the strength of magnetic flux is decreased. Accordingly, the electromagnetic force for attracting the lower disk 20 to the attraction surface 61 b is decreased.
  • the lower disk 20 and the upper disk 30 are oscillated from the center position toward the position at which the lower disk 20 and the upper disk 30 are to be oscillated as much as possible so that the valve is opened due to the electromagnetic force of the electromagnet 60 for attracting the upper disk 30 to the attraction surface 61 a and the magnetic force of the valve opening permanent magnet 55 for attracting the lower disk 20 to the attraction surface 55 a .
  • providing the valve opening permanent magnet 55 makes it possible to prevent the force for opening the drive valve 14 from decreasing particularly when the drive valve 14 is near the valve opening position.
  • the supply of the electric current to the open/close coil 62 is repeatedly started and stopped at the above-mentioned timing.
  • the upper disk 30 and the lower disk 20 are moved so as to be repeatedly oscillated as much as possible so that the valve is opened and oscillated as much as possible so that the valve is closed.
  • the drive valve 14 are reciprocated due to this oscillation motion.
  • the distance between the electromagnet 60 and the lower disk 20 decreases from the first end 22 toward the second end 23
  • the distance between the electromagnet 60 and the upper disk 30 decreases from the first end 32 toward the second end 33 .
  • the electromagnet and the armature of the drive valve to which the electromagnetic force is applied are uniformly apart from each other while the distance therebetween uniformly changes. At a position at which the distance from the electromagnet is shorter, a larger amount of electromagnetic force is applied. Therefore, in the rotary driven type electromagnetically driven valve 10 , a large amount of electromagnetic force can be applied to the drive valve 14 , as compared with the parallel driven type electromagnetically driven valve.
  • the structure is such that the lower disk 20 and the upper disk 30 are movably supported by the disk supporting base 51 and the electromagnet 60 is provided between the lower disk 20 and the upper disk 30 . Therefore, the height of the electromagnetically driven valve 10 can be made low, as compared with the case where an electromagnet is provided above each disk and another electromagnet is provided below each disk.
  • just providing the electromagnet 60 formed of a mono-coil makes it possible to oscillate the upper disk 30 and the lower disk 20 , and to reciprocate the drive valve 14 . As a result, the number of the components of the electromagnet, which are expensive, can be reduced, resulting in a remarkable cost reduction.
  • an electric current is applied to the coil 62 before the lower disk 20 and the upper disk 30 reach the center position.
  • providing the permanent magnets 71 and 72 makes it possible to supply the electric current at this timing in the electromagnetically driven valve 10 using the electromagnet 60 formed of a mono-coil. The reason will be described as follows.
  • the electromagnetic force generated by the electromagnet 60 is applied to the lower disk 20 and the upper disk 30 in the same manner. Namely, in the electromagnetically driven valve in which the permanent magnets 71 and 72 are not provided, if an electric force is applied to the electromagnet 60 when the lower disk 20 and the upper disk 30 are at the center position, as shown in FIG. 6 , the lower disk 20 is attracted to the attraction surface 61 b , and the upper disk 30 is also attracted to the attraction surface 61 a with the same amount of force for attracting the lower disk 20 to the attraction surface 61 b.
  • the time at which the supply of electric current to the coil 62 is started can be set to a time before the lower disk 20 and the upper disk 30 reach the center position.
  • the electromagnetic force generated by the electromagnet 60 can be more effectively applied to the lower disk 20 and the upper disk 30 . It is, therefore, to increase the force for closing the drive valve 14 and the force for opening the drive valve 14 .
  • the electromagnetically driven valve 10 includes the drive valve 14 having the stem 12 serving as the valve stem; the lower disk 20 which serves as an oscillation member, which has the arm portion 21 made of magnetic material, and which extends from the first end 22 connected to the stem 12 toward the second end 23 movably supported by the disk supporting base 51 serving as a supporting member; the upper disk 30 which serves as an oscillation member, which has the arm portion 31 made of magnetic material, and which extends from the first end 32 connected to the stem 12 toward the second end 33 movably supported by the disk supporting base 51 serving as the supporting member; and the open/close electromagnet 60 serving as an electromagnet.
  • the electromagnet 60 includes the open/close core 61 serving as a core provided so as to face the arm portions 21 and 31 ; and the open/close coil 62 serving as a coil provided around the core 61 .
  • the electromagnet 60 forms the magnetic circuit 102 which passes through the core 61 and the arm portion 21 , and the magnetic circuit 101 which passes through the core 61 and the arm portion 31 .
  • the electromagnetically driven valve 10 further includes the permanent magnet 72 that has the magnetic axis along the magnetic circuit 102 and that is provided so as to act on the magnetic flux flowing through the magnetic circuit 102 ; and the permanent magnet 71 that has the magnetic axis along the magnetic circuit 101 and that is provided so as to act on the magnetic flux flowing through the magnetic circuit 101 .
  • the lower disk 20 oscillates by using the second end 23 as a supporting point due to the electromagnetic force applied from the electromagnet 60
  • the upper disk 30 oscillates by using the second end 33 as a supporting point due to the electromagnetic force applied from the electromagnet 60 .
  • the drive valve 14 reciprocates in the direction in which the stem 12 extends due to the oscillation motion of the lower disk 20 and the upper disk 30 transmitted to the drive valve 14 via the first ends 22 and 32 , respectively.
  • the lower disk 20 and the upper disk 30 serving as the oscillation members, are provided in the direction in which the stem 12 , serving as the valve stem, extends, at a predetermined distance from each other.
  • the electromagnet 60 is provided between the lower disk 20 and the upper disk 30 .
  • the coil 62 is formed of a mono-coil.
  • the electromagnetically driven valve 10 further includes the valve opening permanent magnet 55 serving as a first permanent magnet provided so as to be opposed to the electromagnet 60 with the lower disk 20 interposed therebetween; and the valve closing permanent magnet 56 serving as a second permanent magnet provided so as to be opposed to the electromagnet 60 with the upper disk 30 interposed therebetween.
  • a control method of the electromagnetically driven valve according to the first embodiment of the invention is the control method of the above-mentioned electromagnetically driven valve 10 .
  • the control method includes a step in which the lower disk 20 and the upper disk 30 , which have been oscillated as much as possible so that the valve is opened, are started to oscillate toward the position at which the lower disk 20 and the upper disk 30 are to be oscillated as much as possible so that the valve is closed, by stopping the supply of electric current to the electromagnet 60 ; and a step which is performed after the above-mentioned step, and in which the supply of electric current to the electromagnet 60 is started before the lower disk 20 and the upper disk 30 reach the center position that is the midpoint between the position at which the lower disk 20 and the upper disk 30 have been oscillated as much as possible so that the valve is opened and the position at which the lower disk 20 and the upper disk 30 have been oscillated as much as possible so that the valve is closed.
  • control method includes a step in which the lower disk 20 and the upper disk 30 , which have been oscillated as much as possible so that the valve is closed, are started to oscillate toward the position at which the lower disk 20 and the upper disk 30 are to be oscillated as much as possible so that the valve is opened, by stopping the supply of electric current to the electromagnet 60 ; and a step which is performed after the above-mentioned step, and in which the supply of electric current to the electromagnet 60 is started before the lower disk 20 and the upper disk 30 reach the center position that is the midpoint between the position at which the lower disk 20 and the upper disk 30 have been oscillated as much as possible so that the valve is closed and the position at which the lower disk 20 and the upper disk 30 have been oscillated as much as possible so that the valve is opened.
  • the permanent magnets 71 and 72 are provided in the core 61 .
  • the invention is not limited to this.
  • Each of the permanent magnets 71 and 72 may be provided at a position outside the core 61 , as long as the magnetic flux in the permanent magnet 71 formed due to the magnetic poles acts on the magnetic flux flowing through the magnetic circuit 101 , and the magnetic flux in the permanent magnet 72 formed due to the magnetic poles acts on the magnetic flux flowing through the magnetic circuit 102 .
  • the permanent magnet 71 may be provided in the arm portion 31 of the upper disk 30
  • the permanent magnet 72 may be provided in the arm portion 21 of the lower disk 20 .
  • the electromagnetically driven valve 10 With the thus configured electromagnetically driven valve 10 according to the first embodiment of the invention, providing the permanent magnets 71 and 72 in the rotary driven type electromagnetically driven valve makes it possible to increase the force for opening the valve and the force for closing the valve, and to obtain a sufficiently large amount of driving force. It is, therefore, possible to improve the performance of the engine including the electromagnetically driven valve 10 .
  • FIG. 8 illustrates a schematic view of an electromagnetically driven valve according to a second embodiment of the invention.
  • the electromagnetically driven valve according to the second embodiment has the same structure as that of the electromagnetically driven valve 10 according to the first embodiment. Therefore, the description concerning the portions having the same structure as those in the first embodiment will not be made here.
  • permanent magnets 81 and 82 are provided in the electromagnet 60 , instead of the permanent magnets 71 and 72 in the first embodiment.
  • Each of the permanent magnets 81 and 82 is located so as to be adjacent to the shaft portion 61 p , and provided between the core 61 and the coil 62 .
  • the permanent magnet 81 is provided so as to face the upper disk 30
  • the permanent magnet 82 is provided so as to face the lower disk 20 .
  • the magnetic axis is formed along a magnetic circuit 118 formed between the core 61 and the upper disk 30 , and the magnetic flux formed in the permanent magnet 81 due to the magnetic poles flows in the direction shown by an arrow 81 x .
  • the magnetic axis is formed along a magnetic circuit 119 formed between the core 61 and the lower disk 20 , and the magnetic flux formed in the permanent magnet 82 due to the magnetic poles flows in the direction shown by an arrow 82 x that is opposite to the direction shown by the arrow 81 x.
  • the strength of magnetic flux flowing between the core 61 and the upper disk 30 is increased when the lower disk 20 and the upper disk 30 oscillate from the valve closing side toward the valve opening side, and is decreased when the lower disk 20 and the upper disk 30 oscillate from the valve opening side toward the valve closing side. Also, the strength of magnetic flux flowing between the core 61 and the lower disk 20 is decreased when the lower disk 20 and the upper disk 30 oscillate from the valve closing side toward the valve opening side, and is increased when the lower disk 20 and the upper disk 30 oscillate from the valve opening side toward the valve closing side.
  • the same effects as those disclosed in the first embodiment can be obtained.
  • the permanent magnets 81 and 82 are not embedded in the core 61 , the electromagnetically driven valve 60 can be easily produced at low cost.
  • FIG. 9 illustrates a cross sectional view of an electromagnetically driven valve according to a third embodiment of the invention.
  • the electromagnetically driven valve according to the third embodiment has the same structure as that of the electromagnetically driven valve 10 according to the first embodiment. Therefore, the description concerning the portions having the same structure as those in the first embodiment will not be made here.
  • an electromagnet 90 is provided instead of the electromagnet 60 in the first embodiment.
  • the electromagnet 90 includes coils 94 and 95 , and a core 93 that has attraction surfaces 93 a and 93 b , and that is made of magnetic material.
  • the core 93 has a shape obtained by combining a portion 91 and a portion 92 with each other, each of which has a cross sectional area having a substantially “E” shape.
  • the portion 91 is positioned so as to face the upper disk 30 , and has a shaft portion 91 p extending in the direction in which the stem 12 extends.
  • the portion 92 is positioned so as to face the lower disk 20 , and has a shaft portion 92 p extending in the direction in which the stem 12 extends.
  • the coil 94 is provided so as to be around the shaft portion 91 p
  • the coil 95 is provided so as to be around the shaft portion 92 p.
  • the permanent magnet 98 has the magnetic axis along the magnetic circuits 124 and 126 , and the magnetic flux formed in the magnet due to the magnetic poles flows in the direction shown by an arrow 98 x that is opposite to the direction shown by the arrow 97 x.
  • the invention is not limited to this.
  • the invention can be applied to a rotary driven type electromagnetically driven valve including a disk which is connected to the stem 12 at a first end and which is movably supported by the disk supporting base 51 at a second end; and multiple electromagnets which are provided above and below the disk and which alternately apply an electromagnetic force to the disk.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)
  • Magnetically Actuated Valves (AREA)
US11/660,655 2004-08-31 2005-08-24 Electromagnetically Driven Valve Abandoned US20080042089A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2004251288A JP4124183B2 (ja) 2004-08-31 2004-08-31 電磁駆動弁およびその制御方法
JP2004-251288 2004-08-31
PCT/IB2005/002503 WO2006024914A2 (en) 2004-08-31 2005-08-24 Electromagnetically driven valve

Publications (1)

Publication Number Publication Date
US20080042089A1 true US20080042089A1 (en) 2008-02-21

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Application Number Title Priority Date Filing Date
US11/660,655 Abandoned US20080042089A1 (en) 2004-08-31 2005-08-24 Electromagnetically Driven Valve

Country Status (4)

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US (1) US20080042089A1 (enExample)
EP (1) EP1802854A2 (enExample)
JP (1) JP4124183B2 (enExample)
WO (1) WO2006024914A2 (enExample)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070221873A1 (en) * 2004-07-09 2007-09-27 Yutaka Sugie Electromagnetically Driven Valve
US20090266319A1 (en) * 2008-04-28 2009-10-29 James Douglas Ervin System and method for providing hydraulic valve lash compensation for electrically actuated internal combustion engine poppet valves

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19824537A1 (de) * 1998-06-03 1999-12-09 Lsp Innovative Automotive Sys Elektromagnetische Stelleinrichtung
JP3547115B2 (ja) * 1998-06-11 2004-07-28 トヨタ自動車株式会社 電磁駆動バルブ
JP4126787B2 (ja) * 1998-12-07 2008-07-30 トヨタ自動車株式会社 電磁駆動装置
FR2792451B1 (fr) * 1999-04-15 2001-06-15 Renault Dispositif d'actionnement electromagnetique
DE10000045A1 (de) * 2000-01-02 2001-07-05 Leiber Heinz Elektromagnetischer Aktuator
JP2002364391A (ja) * 2001-06-08 2002-12-18 Toyota Motor Corp 電磁駆動弁の中立位置変化検出装置
FR2849100B1 (fr) * 2002-12-23 2006-08-04 Johnson Controls Tech Co Actionneur electromagnetique monobobine a palette pivotante

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070221873A1 (en) * 2004-07-09 2007-09-27 Yutaka Sugie Electromagnetically Driven Valve
US20090266319A1 (en) * 2008-04-28 2009-10-29 James Douglas Ervin System and method for providing hydraulic valve lash compensation for electrically actuated internal combustion engine poppet valves

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WO2006024914A2 (en) 2006-03-09
JP2006070706A (ja) 2006-03-16
WO2006024914A3 (en) 2006-07-13
EP1802854A2 (en) 2007-07-04
JP4124183B2 (ja) 2008-07-23

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