Electromagnetically Driven Valve

Abstract

An electromagnetically driven valve includes a drive valve that has a stem; an upper disk and a lower disk each of which has an arm portion, and each of which extends from a first end that is movably connected to the stem toward a second end that is movably supported by a disk supporting base; 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 a magnetic circuit that passes through the core and the arm portion when an electric current is applied to the coil. The electromagnetically driven valve further includes a permanent magnet which has a magnetic axis along the magnetic circuit, and which is provided so as to act on a magnetic flux that flows through the magnetic circuit.

1 . An electromagnetically driven valve comprising: 
 a drive valve that has a valve stem and that 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 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;    an electromagnet which includes a core that is provided so as to face the arm portion, and a coil that is wound around the core, and which 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; and    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, 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 oscillation members is are oscillated by using the second end as a supporting point due to an electromagnetic force applied from the electromagnet, and    an oscillation motion of the oscillation members is transmitted to the drive valve via the first end, whereby the drive valve reciprocates in the direction in which the valve stem extends.    
   
   
       2 . The electromagnetically driven valve according to  claim 1 , wherein 
 the permanent magnet is provided in the core.    
   
   
       3 . The electromagnetically driven valve according to  claim 1 , wherein 
 the permanent magnet is provided between the core and the coil.    
   
   
       4 . The electromagnetically driven valve according to  claim 1 , wherein 
 the permanent magnet is embedded in the core, and the core is divided into two areas by the electromagnet on the magnetic circuit.    
   
   
       5 . The electromagnetically driven valve according to  claim 4 , wherein 
 the coil is formed of a first coil that faces the arm portion of the first oscillation member, and a second coil that faces the arm portion of the second oscillation member.    
   
   
       6 . A control method for an electromagnetically driven valve including a drive valve that has a valve stem and that 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 that 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 method comprising: 
 a first step in which a supply of an electric current to the electromagnet is stopped, whereby the oscillation members, which are 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 members reach a center position that is a midpoint between the first position and the second position.    
   
   
       7 . The control method for an electromagnetically driven valve according to  claim 6 , wherein 
 the first position is a position at which the oscillation members have been oscillated as much as possible so that the drive valve is opened; and    the second position is a position at which the oscillation members have been oscillated as much as possible so that the drive valve is closed.    
   
   
       8 . The control method for an electromagnetically driven valve according to  claim 6 , wherein 
 the first position is a position at which the oscillation members have been oscillated as much as possible so that the drive valve is closed; and    the second position is a position at which the oscillation members have been oscillated as much as possible so that the drive valve is opened.