阅读说明：本技术 点火器组件及其绝缘体和构造方法 (Igniter assembly, insulator therefor and method of construction ) 是由 詹姆斯·D·利科斯基 保罗·威廉·菲利普斯 于 2018-04-11 设计创作，主要内容包括：提供一种诸如用于内燃机的电晕点火器的点火器,以及制造该点火器的方法。点火器包括绝缘体,绝缘体具有扩大的上端区域和下端区域,轴向地延伸超过壳体通道的受约束的较小直径的区域的相对端。绝缘体的扩大的下端区域沿壳体的下端轴向外侧布置。绝缘体被气密地密封到壳体上,并且被永久地固定,以防止其从壳体轴向向外移除。该方法可以包括通过使壳体塑性变形或者围绕绝缘体铸造壳体而使壳体与绝缘体的轮廓相匹配。可替代地,可以将分开的金属部件布置在绝缘体周围以形成与绝缘体相匹配的壳体。(An igniter, such as a corona igniter for an internal combustion engine, and a method of making the igniter are provided. The igniter includes an insulator having enlarged upper and lower end regions extending axially beyond opposite ends of the restricted smaller diameter region of the housing passage. An enlarged lower end region of the insulator is disposed axially outwardly of the lower end of the shell. The insulator is hermetically sealed to the housing and permanently secured to prevent its removal axially outward from the housing. The method may include matching the shell to the contour of the insulator by plastically deforming the shell or casting the shell around the insulator. Alternatively, a separate metal component may be disposed around the insulator to form a housing that mates with the insulator.)

1. A corona igniter, comprising:

an insulator surrounding the center electrode;

the insulator has an insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region;

the insulator middle region has a maximum first diameter ID1, the insulator upper end region has a minimum second diameter ID2, and the insulator lower end region has a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are both greater than the maximum first diameter D1;

a housing formed of metal surrounding the insulator;

the housing having a housing outer surface including a threaded region having a plurality of threads;

the housing having a housing inner surface including a housing lower end region radially aligned with the threaded region;

the maximum inside diameter SD1 of the lower end region of the shell is less than the minimum second diameter ID2 and the minimum third diameter ID3 of the insulator outer surface;

the shell is plastically deformed so that the shell inner surface matches the contour of the insulator middle region; and is

The insulator lower end region extends axially outwardly from a shell lower end of the shell.

2. The corona igniter of claim 1, wherein the insulator outer surface includes an insulator nose region extending and tapering continuously from the insulator lower end region to an insulator nose end.

3. The corona igniter of claim 1, wherein the insulator upper end region is bulbous, the maximum first diameter ID1 of the insulator middle region is constant and extends continuously from the insulator upper end region to the insulator lower end region, the minimum third diameter ID3 of the insulator lower end region is constant, and the insulator outer surface includes an insulator nose region that extends continuously and tapers from the insulator lower end region to an insulator nose end.

4. The corona igniter of claim 1, wherein the insulator lower end region extends axially outwardly from the shell lower end.

5. The corona igniter of claim 1, wherein the threaded region of the housing outer surface extends axially to a housing shoulder providing a seat for sealing against a mounting surface of an engine cylinder head.

6. The corona igniter of claim 5, wherein the shell is plastically deformed along the threaded region adjacent the shell shoulder.

7. The corona igniter of claim 1, wherein the insulator is permanently secured against removal axially outward from the housing.

8. The corona igniter of claim 1, including a braze seal material and/or a gasket to provide a hermetic seal between the insulator outer surface and the shell inner surface.

9. The corona igniter of claim 1, wherein the central electrode is formed of an electrically conductive material for receiving a high radio frequency voltage;

the center electrode extending longitudinally along a central axis from a terminal end to an electrode firing end;

the central electrode comprises a corona enhancing tip for emitting a radio frequency electric field in the range of 0.9 to 1.1 MHz;

the corona enhancing tip includes a plurality of radially outwardly extending prongs;

the tip is formed of nickel, nickel alloy, copper alloy, iron, or iron alloy;

the insulator is a single piece of electrically insulating material extending longitudinally from an insulator upper end to an insulator nose end;

the insulator outer surface includes an insulator nose region continuously extending and tapering from the insulator lower end region to the insulator nose end;

the maximum first diameter ID1 of the insulator middle region is constant and extends continuously from the insulator upper end region to the insulator lower end region;

the upper end area of the insulator is spherical;

the maximum first diameter ID1 extending along the insulator middle region is constant;

said minimum third diameter ID3 of said insulator lower end region is constant;

the insulator inner surface defining a through-hole that receives the center electrode therein;

the through bore extending longitudinally along the central axis from the insulator upper end to the insulator nose end;

the metal of the housing is steel, which is plastically deformable;

the shell outer surface is radially outward and away from the central axis from a shell upper end to a shell lower end;

the shell inner surface surrounding the insulator intermediate and upper end regions;

said insulator lower end region extending axially outwardly from said housing lower end;

the threaded region of the housing extends axially to a housing shoulder;

the housing shoulder providing a seat for sealing against a mounting surface of an engine cylinder head;

the shoulder extends radially outward and transitions to an axially extending enlarged region of the housing outer surface;

the housing is plastically deformed along the threaded region adjacent the shoulder;

the housing inner surface includes a housing upper region extending opposite the enlarged region of the housing outer surface;

the housing upper region extends radially outward to provide a minimum upper diameter SD 2;

the minimum upper diameter SD2 is greater than the minimum second diameter ID2 of the insulator outer surface;

the insulator is permanently secured to prevent its removal axially outwardly from the housing; and

a braze seal material and/or gasket provides a hermetic seal between the insulator outer surface and the shell inner surface.

10. A corona igniter, comprising:

an insulator surrounding the center electrode;

the insulator has an insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region;

the insulator middle region has a maximum first diameter ID1, the insulator upper end region has a minimum second diameter ID2, and the insulator lower end region has a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are both greater than the maximum first diameter D1;

a housing formed of metal surrounding the insulator;

the housing having a housing outer surface including a threaded region having a plurality of threads;

the housing having a housing inner surface including a housing lower end region radially aligned with the threaded region;

the maximum inside diameter SD1 of the lower end region of the shell is less than the minimum second diameter ID2 and the minimum third diameter ID3 of the insulator outer surface;

the housing comprises separate parts;

the inner surface of the shell matches the contour of at least a portion of the insulator middle region and the insulator upper end region, and

the insulator lower end region extends axially outwardly from a shell lower end of the shell.

11. The corona igniter of claim 10, wherein the split member includes two halves each extending axially from a shell upper end to a shell lower end.

12. The corona igniter of claim 10, wherein the shell inner surface includes an enlarged shell region disposed between the shell lower end region and the shell upper end, the enlarged shell region having a minimum upper diameter SD2 greater than the minimum second diameter ID2 of the insulator outer surface, and the enlarged shell region being provided by a third piece of material separated from the two halves.

13. The corona igniter of claim 10, wherein the insulator is permanently secured against removal axially outward from the housing.

14. A method of making an igniter, comprising the steps of:

providing an insulator, the insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region, the insulator middle region having a maximum first diameter ID1, the insulator upper end region having a minimum second diameter ID2, and the insulator lower end region having a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are both greater than the maximum first diameter ID 1;

inserting the insulator lower end region into a shell upper end of a shell formed of metal and through a shell lower end of the shell; and

plastically deforming the shell to match an inner shell surface of the shell to a contour of the insulator middle region.

15. The method of claim 14, wherein the step of plastically deforming comprises a cold forming process or a magnetic pulse forming process.

16. The method of claim 14, wherein the insulator lower end region extends axially outwardly from a shell lower end of the shell.

17. A method of making an igniter, comprising the steps of:

providing an insulator, the insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region, the insulator middle region having a maximum first diameter ID1, the insulator upper end region having a minimum second diameter ID2, and the insulator lower end region having a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are both greater than the maximum first diameter D1; and

separate pieces of a shell formed of metal are disposed around the insulator outer surface, the shell inner surface of each piece of the shell matching the contour of at least a portion of the insulator middle region and the insulator upper end region.

18. The method of claim 16, comprising brazing the insulator to the shell.

19. The method of claim 16, wherein the step of disposing the shell around the insulator includes disposing a shell lower end of the shell axially above a lower end region of the insulator.

20. A method of making an igniter, comprising the steps of:

providing an insulator, the insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region, the insulator middle region having a maximum first diameter ID1, the insulator upper end region having a minimum second diameter ID2, and the insulator lower end region having a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are both greater than the maximum first diameter D1; and

casting a shell formed of metal around the insulator such that a shell inner surface of the shell matches a contour of at least a portion of the insulator middle region and the insulator upper end region, and a shell lower end of the shell is positioned axially above the insulator lower end region.

1. Field of the invention

The present application relates generally to igniters used to ignite fuel-air mixtures in internal combustion engines, and to the construction and manufacturing methods of insulators and housings of the igniters.

Background

Disclosure of Invention

One aspect of the present application provides a corona igniter. The corona igniter includes an insulator surrounding a central electrode and a shell formed of metal surrounding the insulator. The insulator has an insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region. The middle region has a maximum first diameter ID1, the insulator upper end region has a minimum second diameter ID2, and the insulator lower end region has a minimum third diameter ID 3. The minimum second diameter ID2 and the minimum third diameter ID3 are each greater than the maximum first diameter D1. The housing has a housing outer surface including a threaded region having a plurality of threads. The housing also has a housing inner surface including a housing lower end region radially aligned with the threaded region. The lower end region of the shell has a maximum inside diameter SD1 that is SD1 smaller than the minimum second diameter ID2 and the minimum third diameter ID3 of the insulator outer surface. The shell is also plastically deformed to match the inner surface of the shell with the contour of at least a portion of the insulator middle region and the insulator upper end region, and the insulator lower end region extends axially outwardly from the shell lower end of the shell.

Another aspect of the present application provides a corona igniter including an insulator surrounding a central electrode and a shell formed of metal surrounding the insulator. The insulator has an insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region. The insulator middle region has a maximum first diameter ID1, the insulator upper end region has a minimum second diameter ID2, and the insulator lower end region has a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are both greater than the maximum first diameter D1. The housing has a housing outer surface including a threaded region having a plurality of threads. The housing also has a housing inner surface including a housing lower end region radially aligned with the threaded region. The maximum inner diameter of the lower end region of the shell is less than the minimum second diameter ID2 and the minimum third diameter ID3 of the outer surface of the insulator. The shell comprises separate parts and the inner surface of the shell matches the contour of at least a portion of the insulator middle region and the insulator upper end region. The insulator lower end region also extends axially outwardly from the shell lower end of the shell.

Another aspect of the present application provides a method of making an igniter. The method comprises the following steps: providing an insulator having an insulator outer surface comprising an insulator middle region between an insulator upper end region and an insulator lower end region, the insulator middle region having a maximum first diameter ID1, the insulator upper end region having a minimum second diameter ID2, the insulator lower end region having a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are each greater than the maximum first diameter D1; the insulator lower end region is inserted into and through the shell upper end of the shell formed of metal. The method also includes plastically deforming the shell such that a shell inner surface of the shell matches a contour of the insulator middle region.

Yet another aspect of the present application provides a method of making an igniter, comprising the steps of: providing an insulator having an insulator outer surface including an insulator middle region between an insulator upper end region and an insulator lower end region, the insulator having a middle region of a maximum first diameter ID1, an insulator upper end region having a minimum second diameter ID2, and an insulator lower end region having a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are each greater than the maximum first diameter D1; and arranging separate pieces of a shell formed of metal around the outer surface of the insulator, the shell inner surfaces of the individual pieces of the shell matching the contour of at least a portion of the insulator middle region and the insulator upper end region.

Another aspect of the present application provides a method for manufacturing an igniter, comprising the steps of: providing an insulator having an insulator outer surface comprising an insulator middle region between an insulator upper end region and an insulator lower end region, the insulator middle region having a maximum first diameter ID1, an insulator upper end region having a minimum second diameter ID2, and an insulator lower end region having a minimum third diameter ID3, wherein the minimum second diameter ID2 and the minimum third diameter ID3 are each greater than the maximum diameter first diameter D1; and casting a shell formed of metal around the insulator such that an inner shell surface of the shell matches a contour of at least a portion of the insulator middle region and the insulator upper end region, and a shell lower end of the shell is located axially above the insulator lower end region.