Claims
- 1. An apparatus for inductively heating the frustoconical valve seat surface of a valve port or an engine component having a valve stem bore coaxially disposed with respect to the valve seat surface, said apparatus comprising:
- an inductor coil having a conical surface complementary to the valve seat surface;
- frame means for advancing said coil toward the valve seat with the axis of the coil surface being substantially parallel to the axis of the valve seat;
- bearing means operative between the inductor coil and the frame means accommodating radial and angular movement of said inductor coil to an orientation wherein the axes of the conical surfaces are coincident;
- an elongated nose member having a cylindrical surface coaxial with the conical surface of the valve seat, said cylindrical surface having a close telescopic sliding fit with and entering the bore of said port upon advancing of said frame means and when received therewithin establishing coincidence of the axes as accommodated by said bearing means; and,
- non-magnetic insulating spacer means attached to said conical surface of said coil having outer reference surfaces thereon lying on a conical surface spaced from the inductor coil a predetermined distance thereby prescribing concentricity and axial spacing between the conical surfaces of the seat and said coil.
- 2. The apparatus as recited in claim 1 wherein said spacer means are formed of a ceramic material.
- 3. The apparatus as recited in claim 1 wherein said spacer means are in the form of conical segments uniformly circumferentially spaced about the conical surface of said inductor coil.
- 4. The apparatus as recited in claim 1 wherein said bearing means provide free translation of said coil in a radial plane transverse to the axis of said frame means and limited angularity with respect thereto.
- 5. An apparatus as defined in claim 1, wherein said spacer means have a predetermined circumferential spacing about said coil surface.
- 6. An apparatus as defined in claim 1, wherein at least one of said spacer means is formed as an arcuate conical segment having a predetermined circumferential location and arcuate extent at said conical surface.
- 7. An inductor for inductively heating a frustoconical work surface of an engine component and for an induction heating apparatus including a frame movable along a first axis, said inductor comprising: an inductor body having a second axis; an inductor coil of generally rectangular hollow cross section, said coil having an outer frustoconical surface coaxial with said second axis; a plurality of discrete, heat resistant, electrically non-conductive spacer pads attached to said outer frustoconical surface of said coil, said spacer pads having outer reference surfaces commonly lying in a unique conical surface of the same conical angle as said frustoconical surface of said coil and spaced a predetermined axial distance therefrom, said reference surfaces providing cam surfaces for concentric alignment of said coil with said frustoconical work surface; and said spacer pads providing a predetermined axial inductive coupling distance between said coil and said frustoconical work surface.
- 8. The inductor as recited in claim 7 including a housing having a first part connected to the frame and a second part connected to said inductor body, and bearing means between said first part and said second part accommodating radial movement in a plane transverse to said second axis and limited angular movement of the said first part with respect to said second part.
- 9. An apparatus as defined in claim 7, wherein said spacer pads have a predetermined circumferential spacing about said coil surface.
- 10. An apparatus as defined in claim 7, wherein at least one of said spacer pads is formed as an arcuate conical segment having a predetermined circumferential location and arcuate extent at said conical surface.
- 11. A method of locating a conical inductor coil concentrically with respect to a conical valve seat of an engine component and at a predetermined axial spacing therefrom for inductive heating of the valve seat comprising the steps of:
- a. advancing the inductor coil toward the valve seat;
- b. radially shifting and angularly deflecting the coil with respect to the valve seat during said advancing by mechanical coaction therebetween until the conical surfaces of the valve seat and the coil are concentrically disposed along a common axis;
- c. providing non-magnetic spacers on the conical surface of the coil having reference surfaces lying on a conical surface coaxial with the conical surface of the coil and axially spaced therefrom equal to said predetermined axial spacing;
- d. seating said reference surfaces against the conical valve seat during said advancing after the coil and the valve seat are concentrically disposed along said common axis;
- e. terminating said advancing after said seating of said reference surfaces;
- f. energizing said inductor coil and heating said valve seat to a predetermined elevated temperature; and,
- g. retracting said coil from said valve seat.
- 12. A method as defined in claim 11, further comprising the step of providing said spacers in a predetermined circumferentially spaced relationship.
- 13. A method as defined in claim 11, further comprising the step of providing at least one of said spacers in the form of an arcuate conical segment having a predetermined circumferential location and arcuate extent about said coil surface.
- 14. An apparatus for inductively heating the frustoconical valve seat surface of a valve port of an engine component having a valve stem bore coaxially disposed with respect to the valve seat surface, said apparatus comprising:
- an inductor coil having a conical surface complementary to the valve seat surface;
- frame means for advancing said coil toward the valve seat with the axis of the coil surface being substantially parallel to the axis of the valve seat;
- bearing means operative between said inductor coil and said frame means accommodating radial and angular movement of said inductor coil to an orientation wherein the axes of said conical surfaces are coincident;
- means carried with said inductor coil cooperating with the bore of said port upon advancing of said frame means for establishing coincidence of said axes as accommodated by said bearing means; and,
- electrically passive spacer means on said conical surface of said coil directly engaging said frustoconical valve seat surface for prescribing concentricity and axial spacing between said coil and said valve seat surface.
- 15. A method of inductively heating a conical valve seat comprising the steps of:
- a. providing an inductor coil having a conical surface complementary to the valve seat;
- b. providing a plurality of discrete, electrically non-conductive heat resistant spacer pads on said conical surface of the coil, said pads having frontal surfaces commonly lying on a unique conical surface uniformly spaced a predetermined distance from said conical surface of said coil;
- c. seating said frontal surfaces of said spacer pads against the conical valve seat thereby providing a predetermined coupling between said inductor coil and said valve seat, said coupling corresponding to the thickness of said spacer pads; and,
- d. energizing said inductor coil to heat said valve seat to a predetermined elevated temperature.
- 16. An inductor for inductively heating a conical workpiece surface and comprising: an inductor body having an axis; an inductor coil of generally rectangular hollow cross section, said coil having an outer frustoconical surface coaxial with said axis and complementary to said conical workpiece surface a plurality of heat resistant, electrically non-conductive spacer pads attached to said outer frustoconical surface of said coil, said spacer pads each having an outer reference surface receivable on said conical workpiece surface and lying in a unique conical surface of the same conical angle as said frustoconical surface of said coil and spaced a predetermined axial distance therefrom, said reference surfaces having predetermined circumferential locations and arcuate extent with respect to said conical coil surface; and, said spacer pads providing an induction heating coupling distance between said coil and said workpiece surface corresponding to said predetermined axial distance when said reference surface is received on said conical workpiece surface.
Parent Case Info
This is a continuation of Ser. No. 712,744, filed Mar. 18, 1985, now abandoned.
US Referenced Citations (14)
Continuations (1)
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Number |
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712744 |
Mar 1985 |
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