Electromagnetically driven valve

Abstract

An electromagnetically driven valve includes a valve-opening side moving element and a valve-closing side moving element having rotatably supported support portions and carrying out oscillating movement between a valve-opening position and a valve-closing position around the support portions respectively, and an electromagnet having a coil implemented by a monocoil and arranged between the valve-opening side moving element and the valve-closing side moving element. The valve-opening side moving element and the valve-closing side moving element are held at a position intermediate between the valve-opening position and the valve-closing position while electromagnetic force is not applied. Magnetic permeability of a material forming the valve-opening side moving element is different from that of a material forming the valve-closing side moving element. According to such a structure, an electromagnetically driven valve with a simplified structure, of which initial drive is facilitated, is provided.

1 . An electromagnetically driven valve, comprising: 
 first and second moving elements having rotatably supported support portions and carrying out oscillating movement between a valve-opening position and a valve-closing position around said support portions respectively; and    an electromagnet having a monocoil and arranged between said first moving element and said second moving element; wherein    said first and second moving elements are held at a position intermediate between said valve-opening position and said valve-closing position while electromagnetic force is not applied, and as a result of current supply to said monocoil, the electromagnetic force in a direction toward said valve-opening position and said valve-closing position acts on said first and second moving elements, and    magnetic permeability of a material forming said first moving element is different from magnetic permeability of a material forming said second moving element.    
   
   
       2 . The electromagnetically driven valve according to  claim 1 , wherein 
 said electromagnet further includes first and second core portions around which said monocoil is wound, such that magnetic fluxes pass between said first and second core portions and said first and second moving elements respectively,    when the magnetic permeability of the material forming said first moving element is greater than the magnetic permeability of the material forming said second moving element, magnetic permeability of a material forming said first core portion is greater than magnetic permeability of a material forming said second core portion, and    when the magnetic permeability of the material forming said first moving element is smaller than the magnetic permeability of the material forming said second moving element, magnetic permeability of the material forming said first core portion is smaller than magnetic permeability of the material forming said second core portion.    
   
   
       3 . The electromagnetically driven valve according to  claim 1 , mounted on an internal combustion engine and used to control communication between a combustion chamber and an exhaust port, further comprising a driven valve coupled to said first and second moving elements and moving from a position where it cuts off communication between the combustion chamber and the exhaust port into the combustion chamber along with movement of said first and second moving elements from the valve-closing position to the valve-opening position; wherein 
 the magnetic permeability of the material forming said first moving element is greater than the magnetic permeability of the material forming said second moving element.    
   
   
       4 . An electromagnetically driven valve, comprising: 
 first and second moving elements having rotatably supported support portions and carrying out oscillating movement between a valve-opening position and a valve-closing position around said support portions respectively; and    an electromagnet having a monocoil and arranged between said first moving element and said second moving element; wherein    said first and second moving elements are held at a position intermediate between said valve-opening position and said valve-closing position while electromagnetic force is not applied, and as a result of current supply to said monocoil, magnetic flux flows through said first and second moving elements and the electromagnetic force in a direction toward said valve-opening position and said valve-closing position acts on said first and second moving elements, and    said first moving element is different in shape from said second moving element, on a magnetic circuit through which said magnetic flux passes.    
   
   
       5 . The electromagnetically driven valve according to  claim 4 , wherein 
 when said first and second moving elements are cut in a plane orthogonal to a direction in which said magnetic flux flows, a minimum cross-sectional area of said first moving element on the magnetic circuit through which said magnetic flux flows is different from a minimum cross-sectional area of said second moving element on the magnetic circuit through which said magnetic flux flows.    
   
   
       6 . The electromagnetically driven valve according to  claim 5 , wherein 
 said first and second moving elements further have first and second surfaces each extending on a single surface, facing respective opposing surfaces of said electromagnet and receiving the electromagnetic force, respectively, and    an area of said first surface is different from an area of said second surface.    
   
   
       7 . The electromagnetically driven valve according to  claim 6 , wherein 
 said electromagnet further has first and second attraction and contact surfaces each extending on a single surface, facing said first and second surfaces and attracting said first and second moving elements respectively, and    when the area of said first surface is greater than the area of said second surface, an area of said first attraction and contact surface is greater than an area of said second attraction and contact surface, and when the area of said first surface is smaller than the area of said second surface, the area of said first attraction and contact surface is smaller than the area of said second attraction and contact surface.    
   
   
       8 . The electromagnetically driven valve according to  claim 4 , mounted on an internal combustion engine and used to control communication between a combustion chamber and an exhaust port, further comprising a driven valve coupled to said first and second moving elements and moving from a position where it cuts off communication between the combustion chamber and the exhaust port into the combustion chamber along with movement of said first and second moving elements from the valve-closing position to the valve-opening position; wherein 
 when said first and second moving elements are cut in a plane orthogonal to a direction in which said magnetic flux flows, a minimum cross-sectional area of said first moving element on the magnetic circuit through which said magnetic flux flows is greater than a minimum cross-sectional area of said second moving element on the magnetic circuit through which said magnetic flux flows.    
   
   
       9 . An electromagnetically driven valve, comprising: 
 a moving element having a rotatably supported support portion and carrying out oscillating movement between a valve-opening position and a valve-closing position around said support portion;    an electromagnet having a monocoil and applying electromagnetic force to said moving element, said moving element being held at a position intermediate between said valve-opening position and said valve-closing position while said electromagnetic force is not applied, and as a result of current supply to said monocoil, the electromagnetic force in a direction toward said valve-opening position and said valve-closing position acting on said moving element; and    an actuator applying force in a direction to move said moving element to any one of said valve-opening position and said valve-closing position to said moving element held at said intermediate position.    
   
   
       10 . The electromagnetically driven valve according to  claim 9 , mounted on an internal combustion engine, wherein 
 said actuator is driven by power generated when said internal combustion engine is driven.