Ignition coil assembly for internal combustion engines

Abstract

An ignition coil assembly for an internal combustion engine includes at least one first laminated core contained in a housing and having a plurality of first magnetic path connection end faces exposed to the inside of the housing and at least one second laminated core having a plurality of second magnetic path connection end faces each opposing to one of the first magnetic path connection end faces through a thin gap. A primary coil and secondary coil are wound on the second laminated core, and a plurality of soft waterproof layers are formed on inner walls of the housing to cover the first magnetic path connection end faces of the first laminated core.

I claim: 
     
       1. An ignition coil assembly for an internal combustion engine comprising: a housing made of an electrically insulating material;   at least one first laminated core embedded in said housing and having a plurality of surface portions exposed to the outside of said housing and a plurality of magnetic path connection end faces exposed to the inside of said housing;   at least one second laminated core having a plurality of magnetic path connection end faces each opposing through a small gap one of said magnetic path connection end faces of said first laminated core and contained in said housing to form, along with said first laminated core, a closed magnetic path;   a primary coil and a secondary coil which are wound on said second laminated core;   a molding resin filling in said housing to insulate and fix in place said second laminated core, said primary coil and said secondary coil; and   a plurality of soft waterproof layers formed on inner walls of said housing to cover said magnetic path connection end faces of said first laminated core.   
     
     
       2. An ignition coil assembly according to claim 1, wherein each of said waterproof layers is formed by adhering a soft plastic film to one of said magnetic path connection end faces. 
     
     
       3. An ignition coil assembly according to claim 1, wherein each of said waterproof layers is formed by adhering a waterproof tape made by successively bonding an adhesive layer, a polyester film layer and an adhesive layer to a glass cloth to one of said magnetic path connection end faces. .Iadd. 
     
     
       4.  An ignition coil assembly for an internal combustion engine comprising: a single housing made of an electrically insulating material;   two first laminated cores embedded in said single housing and having a plurality of magnetic path connection end faces exposed to an inside of said housing, respectively;   two second laminated cores, in said single housing, having a plurality of magnetic path connection end faces each opposing one of said magnetic path connection end faces of said first laminated cores through a small gap and contained in said housing to form, along with said first laminated cores, a closed magnetic path, respectively;   two primary coils and two secondary coils which are in said single housing and are wound on said second laminated cores respectively;   a molding resin filling in said single housing to insulate and fix in place said second laminated cores, said primary coils and said secondary coils; and   a plurality of soft waterproof layers formed on inner walls of said housing to cover said magnetic path connection end faces of said first laminated cores. .Iaddend. .Iadd.   
     
     
       5.  An ignition coil assembly according to claim 4, wherein each of said secondary coils includes a secondary bobbin externally fixed on the primary winding and a secondary winding wound on an outer periphery of the secondary bobbin, and each said secondary bobbin having locking members which are attached to ends of the secondary bobbins to mount the two secondary bobbins in a locked form in the housing. .Iaddend. .Iadd. 
     
     
       6.  An ignition coil assembly according to claim 5, wherein each of said primary coils includes a primary bobbin externally fitted on each said second laminated core and a first winding wound on the primary bobbin, and each said primary bobbin having engagement members adapted for engagement of the housing. .Iaddend. .Iadd. 
     
     
       7.  An ignition coil assembly according to claim 6, wherein said housing is formed with a notch on the side wall thereof, and further comprising a terminal box which includes a resin box having slots formed in conformity with the notch and terminals connected to the primary windings. .Iaddend. .Iadd.8. An ignition coil assembly according to claim 4, wherein said housing is made of an electrically insulating and thermal shock resistant resin and includes a container-type accommodation portion for receiving the primary coils and the secondary coils and a pair of core enclosures and which are respectively made integral with the first laminated cores and arranged along an outer periphery of the container-type accommodation portion. .Iaddend. .Iadd.9. An ignition coil assembly according to claim 8, wherein said two first laminated cores are formed substantially C-shaped and said two second laminated cores are formed substantially 
     
     
        I-shaped. .Iaddend. .Iadd.10.  An ignition coil assembly according to claim 9, wherein each of said secondary coils includes a secondary bobbin externally fixed on the primary winding and a secondary winding wound on an outer periphery of the secondary bobbin, and each said secondary bobbin having locking members which are attached to ends of the secondary bobbins to mount the two secondary bobbins in a locked form in the housing. .Iaddend. .Iadd.11. An ignition coil assembly according to claim 10, wherein each of said primary coils includes a primary bobbin externally fitted on each said second laminated core and a first winding wound on the primary bobbin, and each said primary bobbin having engagement members 
     
     
        adapted for engagement of the housing. .Iaddend. .Iadd.12.  An ignition coil assembly according to claim 11, wherein said housing is formed with a notch on the side wall thereof, and further comprising a terminal box which includes a resin box having slots formed in conformity with the notch and terminals connected to the primary windings. .Iaddend.