Apparatus for estimating valve-clearance of an electro-magnetically operated valve and valve-operation controller for the electro-magnetically operated valve

A control apparatus for controlling the operation of an electro-magnetically operated valve comprising:

• a valve drive element;
• a valve element driven by said valve drive element;
• a pair of electromagnets arranged to be spaced apart from one another via said valve drive element and generating, upon being electrically excited, an electro-magnetic force acting on said valve drive element;
• said valve drive element and said valve element when in contact form a moving body of said electro-magnetically operated valve, wherein said moving body includes only said valve drive element when said valve element is not in contact with said valve drive element;
• and
• a pair of springs exhibiting a spring force acting on said valve drive element, said electro-magnetic force and said spring force permitting said valve drive element to move thereby causing a movement of said valve element toward either one of valve-closing and valve-opening positions of said electro-magnetically operated valve;
• said control apparatus comprising:
• an apparatus for estimating a valve-clearance that is a minute spacing produced between said valve drive element and said valve element, said valve-clearance estimating apparatus comprising a position sensor for determining a position of said valve drive element during a movement of said valve drive element, a mass-change estimating portion that estimates a change in a mass of said moving body, and
• a valve-clearance estimating portion estimating said valve-clearance on the basis of said position of said valve drive element determined by said position sensor in coordination with the estimate of the change in said mass of said moving body is estimated;
• and
• a control-switch arranged to switch a control gain in controlling the operation of said electro-magnetically operated valve in response to a position of said valve drive element determined by said position sensor of said valve-clearance estimating apparatus and a valve-clearance estimated by said valve-clearance estimating apparatus.

A method of controlling the operation of an electro-magnetically operated valve which is provided with:

• a valve drive element;
• a valve element driven by said valve drive element;
• a pair of electromagnets arranged to be spaced apart from one another via said valve drive element and generating, upon being electrically excited, an electro-magnetic force acting on said valve drive element, said valve drive element and said valve element when in contact form a moving body of said electro-magnetically operated valve, wherein said moving body includes only said valve drive element when said valve element is not in contact with said valve drive element;
• a pair of springs exhibiting a spring force acting on said valve drive element, said electro-magnetic force and said spring force permitting said valve drive element to move thereby causing a movement of said valve element toward either one of valve-closing and valve-opening positions of said electro-magnetically operated valve;
• and an apparatus for estimating a valve-clearance that is a minute spacing produced between said valve drive element and said valve element, said valve-clearance estimating apparatus comprising a position sensor determining an instant position of said valve drive element during a movement of said valve drive element, a mass-change estimating portion estimating a change in a mass of and said moving body, and a valve-clearance estimating portion estimating said valve-clearance on the basis of said position of said valve drive element determined by said position sensor at a time when said mass of said moving body is estimated, said method comprising:
• switching a control gain in controlling the operation of said electro-magnetically operated valve in response to a position of said valve drive element determined by said position sensor of said valve-clearance estimating apparatus and a valve-clearance estimated by said valve-clearance estimating apparatus.

A method of estimating a valve clearance that is a minute spacing produced between a valve drive element and a valve element which when in contact form a moving body of an electro-magnetically operated valve which further includes a pair of electromagnets arranged to be spaced apart from one another via the valve drive element and generating, upon being electrically excited, an electro-magnetic force acting on the valve drive element, and a pair of springs exhibiting a spring force also acting on said valve drive element, said electro-magnetic force and said spring force permitting said valve drive element to move thereby driving said valve element toward either one of valve-closing and valve-opening positions, wherein said moving body includes only said valve drive element when said valve element is not in contact with said valve drive element, said method comprising:

• sensing a position of said valve drive element during a movement of said valve drive element;
• estimating a change in mass of said moving body;
• and
• estimating said valve clearance on the basis of said position of said valve drive element in coordination with the estimate of the change in mass of said moving body.