Solenoid stator assembly for electronically actuated fuel injectors and method of manufacturing same

A solenoid stator assembly for, electronically actuated fuel injectors, the solenoid stator assembly comprising:

• an E-shaped stator core including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, and a central pole piece extending from a region of the top portion located central to the first and second outer pole pieces and in a direction substantially parallel to those of the first and second outer pole pieces, the first and second outer pole pieces each having an outermost side and the first and second outer pole pieces and the central pole piece each having a distal end, a face being formed across each distal end, the first and second outer pole pieces each having an attachment slot formed across its outermost side proximate its distal end, the slot being substantially parallel to the top portion;
• a coil of electric wire disposed about the central pole piece, the wire having at least first and second ends extending from the coil to form respective first and second leads;
• first and second terminals electrically connected to the first and second leads respectively;
• electrical insulating means for separating the coil from the central pole piece to prevent electrical contact therebetween;
• and
• an insulating cover bonded to at least the stator core and substantially enveloping the solenoid stator assembly except for portions of the first and second terminals and the faces of the first and second outer pole pieces and of the central pole piece, the cover being molded into the attachment slots in the first and second outer pole pieces to enhance adherence of the cover to the first and second outer pole pieces.

A solenoid stator assembly for electronically actuated fuel injectors, the solenoid stator assembly comprising:

• an E-shaped stator core including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, and a central pole piece extending from a region of the top portion located central to the first and second outer pole pieces and in a direction substantially parallel to those of the first and second outer pole pieces, the first and second outer pole pieces and the central pole piece each having a distal end, a face being formed across each distal end;
• a coil of electric wire disposed around the central pole piece, the wire having at least first and second ends extending from the coil to form respective first and second leads;
• first and second terminals electrically connected to the first and second leads respectively;
• electrical insulating means for separating the coil from the central pole piece to prevent electrical contact therebetween;
• prestressing means for applying a force proximate the distal end of the first outer pole piece and a force proximate the distal end of the second outer pole piece, the forces acting in generally coincident but opposite directions to bias the first and second outer pole pieces away from each other;
• and
• an insulating cover bonded to at least the stator core and substantially enveloping the solenoid stator assembly except for portions of the first and second terminals and the faces of the first and second outer pole pieces and of the central pole piece.

A solenoid stator assembly for electronically actuated fuel injectors, the solenoid stator assembly comprising:

• an E-shaped stator core including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, and a central pole piece extending from a region of the top portion located central to the first and second outer pole pieces and in a direction substantially parallel to those of the first and second outer pole pieces, the first and second outer pole pieces each having an outermost side and the first and second outer pole pieces and the central pole piece each having a distal end, a face being formed across each distal end, the first and second outer pole pieces each having an attachment slot formed across its outermost side proximate its distal end, the slot being substantially parallel to the top portion;
• a coil of electric wire disposed around the central pole piece, the wire having at least first and second ends extending from the coil to form respective first and second leads;
• first and second terminals electrically connected to the first and second leads respectively;
• electrical insulating means for separating the coil from the central pole piece to prevent electrical contact therebetween;
• prestressing means for applying a force proximate the distal end of the first outer pole piece and a force proximate the distal end of the second outer pole piece, the forces acting in generally coincident but opposite directions to bias the first and second outer pole pieces away from each other;
• and
• an insulating cover bonded to at least the stator core and substantially enveloping the solenoid stator assembly except for portions of the first and second terminals and the faces of the first and second outer pole pieces and of the central pole piece, the cover being molded into the attachment slots in the first and second outer pole pieces to enhance adherence of the cover to the first and second outer pole pieces.

A solenoid stator assembly for electronically actuated fuel injectors, the solenoid stator assembly comprising:

• an E-shaped stator core including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, and a central pole piece extending from a region of the top portion located central to the first and second outer pole pieces and in a direction substantially parallel to those of the first and second outer pole pieces, the first and second outer pole pieces and the central pole piece each having a distal end, a face being formed across each distal end;
• a coil of electric wire disposed around the central pole piece, the wire having at least first and second ends extending from the coil to form respective first and second leads;
• first and second terminals electrically connected to the first and second leads respectively;
• an electrically insulating spool disposed around the central pole piece and between the central pole piece and the coil of electric wire to prevent electrical contact therebetween,
• the spool having an end flange that extends from the first outer pole piece to the second outer pole piece proximate their respective distal ends,
• the portion of the end flange disposed between the first and second outer pole pieces having a dimension that exceeds, by a specific amount, the distance between the first and second outer pole pieces when the first and second outer pole pieces are unbiased, and
• the end flange being inserted into position to apply a force proximate the distal end of the first outer pole piece and a force proximate the distal end of the second outer pole piece, the forces acting in generally coincident but opposite directions to bias the first and second outer pole pieces away from the central pole piece and prestress the first and second outer pole pieces with restorative forces to oppose additional, parallel forces applied to the first and second outer pole pieces and inhibit additional displacement caused thereby;
• and
• an insulating cover bonded to at least the stator core and substantially enveloping the solenoid stator assembly except for portions of the first and second terminals and the faces of the first and second outer pole pieces and of the central pole piece.

A solenoid stator assembly for electronically actuated fuel injectors, the solenoid stator assembly comprising:

• an E-shaped stator core including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, and a central pole piece extending from a region of the top portion located central to the first and second outer pole pieces and in a direction substantially parallel to those of the first and second outer pole pieces, the first and second outer pole pieces each having an outermost side and the first and second outer pole pieces and the central pole piece each having a distal end, a face being formed across each distal end, the first and second outer pole pieces each having an attachment slot formed across its outermost side proximate its distal end, the slot being substantially parallel to the top portion;
• a coil of electric wire disposed around the central pole piece, the wire having at least first and second ends extending from the coil to form respective first and second leads;
• first and second terminals electrically connected to the first and second leads respectively;
• an electrically insulating spool disposed around the central pole piece and between the central pole piece and the coil of electric wire to prevent electrical contact therebetween,
• the spool having an end flange that extends from the first outer pole piece to the second outer pole piece proximate their respective distal ends,
• the portion of the end flange disposed between the first and second outer pole pieces having a dimension that exceeds, by a specific amount, the distance between the first and second outer pole pieces when the first and second outer pole pieces are unbiased, and
• the end flange being inserted into position to apply a force proximate the distal end of the first outer pole piece and a force proximate the distal end of the second outer pole piece, the forces acting in generally coincident but opposite directions to bias the first and second outer pole pieces away from the central pole piece and prestress the first and second outer pole pieces with restorative forces to oppose additional, parallel forces applied to the first and second outer pole pieces and inhibit additional displacement caused thereby;
• and
• an insulating cover bonded to at least the stator core and substantially enveloping the solenoid stator assembly except for portions of the first and second terminals and the faces of the first and second outer pole pieces and of the central pole piece, the cover being molded into the attachment slots in the first and second outer pole pieces to enhance adherence of the cover to the first and second outer pole pieces.

A method for producing a solenoid stator assembly having a stator core including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, the first and second outer pole pieces each having an outermost side and a distal end, a face being formed across the distal end, the first and second outer pole pieces each having an attachment slot formed across its outermost side proximate its distal end, the slot being substantially parallel to the top portion, the method comprising the steps of:

• (a) disposing a coil of electric wire around an insulating spool;
• (b) disposing the insulating spool and coil of wire about at least one of the pole pieces and the top portion;
• (c) applying a permanent spreading force to the first and second outer pole pieces to prestress them;
• (d) connecting the coil across at least two terminals;
• and
• (e) molding an insulating cover that bonds to at least the stator core and that substantially envelopes the solenoid stator assembly except for portions of the terminals and the faces of the first and second outer pole pieces.

A method for producing a solenoid stator assembly having an E-shaped stator core including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, and a central pole piece extending from a region of the top portion located central to the first and second outer pole pieces and in a direction substantially parallel to those of the first and second outer pole pieces, the first and second outer pole pieces each having an outermost side and the first and second outer pole pieces and the central pole piece each having a distal end, a face being formed across the distal end, the first and second outer pole pieces each having an attachment slot formed across its outermost side proximate its distal end, the slot being substantially parallel to the top portion, the method comprising the steps of:

• (a) disposing a coil of electric wire around an insulating spool;
• (b) disposing the insulating spool and coil of wire about the central pole piece;
• (c) applying a permanent spreading force to the first and second outer pole pieces to prestress them;
• (d) connecting the coil across at least two terminals;
• and
• (e) molding an insulating cover that bonds to at least the stator core and that substantially envelopes the solenoid stator assembly except for portions of the terminals and the faces of the first and second outer pole pieces and of the central pole piece.

A system for producing a solenoid stator assembly having an E-shaped stator pole including a top portion having a first end and a second end, a first outer pole piece extending substantially orthogonally from the first end of the top portion, a second outer pole piece extending from the second end of the top portion in a direction substantially parallel to that of the first outer pole piece, and a central pole piece extending from a region of the top portion located central to the first and second outer pole pieces and in a direction substantially parallel to those of the first and second outer pole pieces, the first and second outer pole pieces each having an outermost side and the first and second outer pole pieces and the central pole piece each having a distal end, the first and second outer pole pieces each having an attachment slot formed across its outermost side proximate its distal end, the slot being substantially parallel to the top portion, the system comprising:

• means for disposing a coil of electric wire around an insulating spool;
• means for disposing the insulating spool and coil of wire on the central pole piece;
• means for applying permanent spreading forces to the first and second outer pole pieces to prestress them;
• means for connecting the coil across at least two terminals;
• and
• means for molding an insulating cover that bonds to at least the stator pole and that substantially envelopes the solenoid stator assembly except for portions of the terminals and the faces of the first and second outer pole pieces and of the central pole piece.