CA2012485A1 - Ignition coil - Google Patents
Ignition coilInfo
- Publication number
- CA2012485A1 CA2012485A1 CA002012485A CA2012485A CA2012485A1 CA 2012485 A1 CA2012485 A1 CA 2012485A1 CA 002012485 A CA002012485 A CA 002012485A CA 2012485 A CA2012485 A CA 2012485A CA 2012485 A1 CA2012485 A1 CA 2012485A1
- Authority
- CA
- Canada
- Prior art keywords
- parts
- axially extending
- ignition coil
- portions
- comprised
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
- H01F27/255—Magnetic cores made from particles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P3/00—Other installations
- F02P3/02—Other installations having inductive energy storage, e.g. arrangements of induction coils
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/12—Ignition, e.g. for IC engines
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
- Spark Plugs (AREA)
- Insulation, Fastening Of Motor, Generator Windings (AREA)
Abstract
C-4,143 IGNITION COIL
Abstract of the Disclosure An ignition coil for developing a spark plug firing voltage. The coil is comprised of first and second parts that are formed of iron particles in a binder of electrical insulating material. The parts are connected by a core member that is formed of magnetic material. A primary winding is disposed about the core member winding and a secondary winding is disposed about the primary winding. An axially extending part that is formed of magnetic material is located outside of the secondary winding and magnetically connects the first and second parts.
Abstract of the Disclosure An ignition coil for developing a spark plug firing voltage. The coil is comprised of first and second parts that are formed of iron particles in a binder of electrical insulating material. The parts are connected by a core member that is formed of magnetic material. A primary winding is disposed about the core member winding and a secondary winding is disposed about the primary winding. An axially extending part that is formed of magnetic material is located outside of the secondary winding and magnetically connects the first and second parts.
Description
20~2485 F-1,147 C-4,143 IGNITION COIL
This invention relates to ignition coils and more particularly to ignition coils where the magnetic circuit for the coil is comprised of magnetic parts that are comprised of powdered iron particles that are coated with an electrical insulating material that forms a binder for the particles and which also electrically insulates the particles from each other to form insulating gaps between the particles.
Ignition coils frequently utilize laminated steel material as the magnetic circuit for the primary and secondary windings. An example of this is disclosed in the U.S. patent to House et al, 4,480,377.
There are disadvantages to using steel lamination stacks. Thus, the use of steel lamination causes size and shape restrictions in the packaging of the design.
Further, potting materials for ignition coils are not compatible with sheet electrical steel. Thus, if potting material is applied to laminated stacks, stress cracks are produced at the sharp edges of the steel sheets. Another problem associated with laminated stacks is that the magnetic circuit needs air gaps which must be precisely adjusted durinq the manufacture of the coil. This adjustment of the air gaps is explained in the above-referenced House et al patent.
It, accordingly, is an object of this invention to provide an ignition coil where parts of the magnetic circuit of the coil are formed of iron powder particles that are insulated from each other by an insulating material and where the insulating material binds the particles together. Use of parts formed of iron powder particles and insulating material eliminates the design and manufacturing problems associated with steel laminations. Thus, the parts are compatible with potting material. Further, the composite iron and insulating material can be molded into various shapes. In addition, by utilizing the composite iron powder and insulating material, no air gap need be provided in the magnetic circuit that would require adjustment. Thus, the air gap is distributed throughout the magnetic circuit because individual particles of powdered iron are coated with electrical insulation. Putting it another way, the composite material has many small gaps distributed throughout the material that act like air gaps.
The U.S. patent to Hause 2,885,458 discloses an ignition coil where an annular or toroidal core is formed of an iron powder and a binder, such as phenolic which is molded to shape. This invention differs from this patent, in that among other things, the magnetic circuit is comprised of at least two parts that are arranged to facilitate assembly of the primary and secondary windings of the coil.
In the Drawings:
Figure 1 is a sectional view of an ignition coil made in accordance with this invention;
Figure 2 is an end view of a component of the ignition coil shown in Figure 1;
Figures 3 illustrates a magnetic part that can be used in place of certain of the magnetic parts shown in Figure 1;
Figure 4 is a sectional view taken along line 4-4 of Figure 3;
Figure 5 is a sectional view taken along line 5-5 of Figure 4; and Figure 6 illustrates a modified magnetic circuit for the coil of Figure 1.
Referring now to the drawings and more particularly to Figure 1, the reference numeral 10 designates a generally cup-shaped ignition coil case that is formed of a molded plastic insulating material.
Disposed within the case 10 are two generally L-shaped magnetic parts 12 and 14 that form part of the magnetic circuit for the ignition coil. These parts 12 and 14 are formed of a composite iron powder and electrical insulating material which is compression molded to the shape shown in the drawings. This material will be described in greater detail hereinafter. The parts 12 and 14 are identical and one of these parts is shown in greater detail in Figure 2. For purposes of description, it will be assumed that part 14 is shown in Figure 2. The part 14 has a rectangular hole 14A, an axially extending portion 14B that has an circular inner surface 14C and a radially extending end wall lS portion 14D. Corresponding portions of part 12 have been designated as 12A, 12B, 12C and 12D. The end faces of portions 12B and 14B are engaged along line 15. This engagement is maintained by press fitting parts 12 and 14 between inner opposed surfaces of case 10.
The ignition coil has a core member 16 that is formed of magnetic material. The core member is rectangular in cross-section to match rectangular holes 12A and 14A. The core member 16 is inserted into holes 12A and 14A during assembly of the coil and may have a press-fit with the holes. In the final assembled position of core 16, the opposite ends thereof are located respectively in holes 12A and 14A. The core member 16 magnetically connects magnetic parts 12 and 14 and it also serves as a core for the primary and secondary windings of the ignition coil.
The core member 16 can be formed from a stack of steel laminations, that is, a plurality of steel laminations. Alternatively, core member 16 could be a solid iron rod or bar. Further, core member 16 could .. .:
-:~ .
20~2485 be formed of the same material as parts 12 and 14, that is, a molded composite iron powder and insulating material.
The primary winding of the ignition coil is designated as 18. It is comprised of a number of turns of wire that are wound on and supported by a spool 20 that is formed by insulating material. The spool 20 and primary winding 18 are disposed about core 16.
The secondary winding of the ignition coil is generally designated as 22. The secondary winding is a so-called segment-wound winding si.nce it has a plurality of series-connected winding portions or sections 24 that are wound into annular grooves formed in coil spool 26. Twelve individual winding sections are shown in Figure 1. The spool 26 is formed from an electrical insulating material.
To assemble the ignition coil that has been described, one end of core 16 can be inserted into, for example, the hole 12A in part 12. A primary winding unit comprised of spool 20 and primary winding 18 carried thereby is now assembled over core 16.
Following this a secondary winding unit comprised of spool 26 and the secondary winding carried thereby is assembled over the primary winding unit. The part 14 is now assembled such that the end of core 16 is inserted into hole or opening 14A and such that end surfaces of portions 12B and 14B are in contact.
When the parts have been assembled as described, they are placed in case 10 and the parts are then encapsulated by a potting compound formed by insulating material that is designated as 28. This potting compound closes the open end of case 10. The potting compound secures the parts of the coil together and bonds to the case 10 to retain the parts of the ignition coil in case 10. Putting it another way, the potting compound fills open spaces in and around the parts of the ignition coil.
Figures 3-5 illustrate a magnetic part 30 that may be substituted for the parts 12 and 14 of the ignition coil shown in Figure 1. The part 30iS formed of magnetic material of the same type that is used for parts 12 and 14, that is, a molded composite iron powder and insulating material. Part 30 has end portions 30A and 30B joined by axially extending portion 30C. End portions 30A and 30B, respectively, have open-ended radially extending slots 30D and 30E.
The slots 30D and 30E receive the ends of a core member, like core member 16 which is press fitted to the slots. It will be appreciated that portion 30C
performs the same function as portions 12B and 14B of the arrangement shown in Figure 1.
Figure 6 illustrates another modified magnetic circuit. In Figure 6, parts 32 and 34 are substituted for parts 12, 14 and 16 of Figure 1. Coils 18 and 24 are shown diagrammatically and would have coil spools like the ones shown in Figure 1. Parts 32 and 34 are formed of the same type of magnetic material as parts 12 and 14, that is, a composite iron powder and insulating material. Part 32 has an axially extending portion 32A, the end face of which abuts or engages the end face of axially extending portion 34A of part 34.
Portions 32A and 34A correspond to portions 12B and 14B
of Figure 1 and have the same shape as these parts. In Figure 6, the core for primary winding 18 and secondary winding 22, rather than being a separate part, is formed by engaged axially extending portions 32B and 34B of parts 32 and 34. Portions 32B and 34B are integral with and extend axially from end wall portions 32C and 34C of parts 32 and 34. Portions 32B and 34B
can be square in cross-section like core member 16 or could have a circular cross-section.
As previously described, parts 12, 14, 16, 30, ; "
32 and 34 can all be formed of a composite magnetic material, that is, particles of powdered iron in a binder formed of electrical insulating material. The final compression molded product should be such that individual iron particles are coated by the insulating material. The insulating material then forms two functions, namely, it insulates particles from each other and it binds the particles together. The electrical insulating coating on and between iron particles act like many small air gaps distributed throughout the material. The gaps, of course, are not actually formed of air, but since insulating material has about the same permeability as air, an air gap effect is achieved.
This invention is not restricted to the type of iron particle powder that is used nor to the type of particle insulation that is used. The mean particle size of the iron particles may be about 0.004 inches.
One example of an iron powder is a Hoeganeas Corp.
1000B powder. This powder can be mixed with a suitable epoxy resin powder and the mixture is then compacted in a press or mold to the desired shape. The part is then cured and the resultant product is a material where the particles are insulated from each other by the epoxy insulating material which also serves to bind the particles together. The final product may have a range of about .5 to 2% by weight of epoxy material with the remainder being iron powder.
The composite material may be comprised of iron particles which are bound together and separated by a cured thermoplastic material. Thus, iron particles of a mean particle size of about 0.004 inches can be coated with a thermoplastic material. The coated particles are placed in a heated mold and then compression molded to the desired shape and density.
The final product is a composite part that is comprised :
20~2485 of cured thermoplastic material and iron particles.
The cured thermoplastic materials binds the particles together and serves to insulate a majority of the particles from each other. However, it is possible that some of the iron particles will become engaged during molding pressure but the final product has a multiplicity of gaps that act like air gaps. The final molded part, by volume, may be about 96% iron powder and about 4~ thermoplastic material.
In a conventional ignition coil design utilizing sheet metal laminations, the density of the sheet steel is a constant value. Therefore, the amount of iron designed into the circuit (to prevent saturation of the circuit with flux density) is controlled by the cross sectional area and stacking factor of the lamina. Also, the steel sheet is continuous, therefore, the air gap designed into the circuit (to control the primary inductance needed to provide the desired energy storage) is controlled by the amount that is physically cut out of the circuit.
In an ignition coil design utilizing electrically insulated iron particles, the density of the powdered metal form is variable. Therefore, the amount of iron designed into the circuit is controlled by the cross sectional area and the density attained by the powdered metal compaction process. Also, the powdered iron particles are insulated from each other by the electrical insulating coating, therefore, the air gap designed into the circuit is controlled by the number of coated powdered iron particles present in the powdered metal form and the space between them. The number of coated iron particles present and the spacing between them are determined by the length of the flux path designed in the form, the cross sectional area, and the density attained by the powdered metal compaction process.
' There is a relationship between the amount of iron and air gap present with respect to the flux density generated in the powdered metal form.
This relationship can be explained as follows. For a given ignition coil design, utilizing a known powdered metal material quantity, the quantity of iron and amount of air gap needed to provide the desired coil performance can be determined. Then, to develop the size and shape of the magnetic circuit, the cross sectional area must be made optimum. If there is not enough cross sectional area, the flux density will be too high and saturate the iron. The iron saturation will cause poor performance due to low energy transfer efficiency and high core losses. If there is too much cross sectional area, the flux density will be too low and the lines of flux will bypass the air gaps. The number of gaps present may have been sufficient to provide enough stored energy, but they were not all utilized in the magnetic circuit. Therefore, there will still be an apparent saturation of the iron and a poor performance due to low energy transfer efficiency and high core losses.
Therefore, when there is too much iron in the magnetic circuit because of too much cross sectional area, even though the cumulative air gap caused by the particle coatings and the spacing between the particles is correct with respect to the ignition coil design, the lines of flux are selective and only utilize a portion of the air gaps. This results in an undesirable situation. If the situation is over corrected by reducing the cross sectional area too much, the iron becomes saturated. This results in an undesirable situation~ The point where the iron is being fuily utilized but not saturated, and the air gaps are being fully utilized but not saturated is the design window desired for the most efficient ignition coil design utilizing electrical insulated powdered metal particles for the magnetic circuit.
To achieve optimum results, the magnetic circuit is designed in a manner that has been described with due regard to the electrical performance to be achieved by a given coil design.
This invention relates to ignition coils and more particularly to ignition coils where the magnetic circuit for the coil is comprised of magnetic parts that are comprised of powdered iron particles that are coated with an electrical insulating material that forms a binder for the particles and which also electrically insulates the particles from each other to form insulating gaps between the particles.
Ignition coils frequently utilize laminated steel material as the magnetic circuit for the primary and secondary windings. An example of this is disclosed in the U.S. patent to House et al, 4,480,377.
There are disadvantages to using steel lamination stacks. Thus, the use of steel lamination causes size and shape restrictions in the packaging of the design.
Further, potting materials for ignition coils are not compatible with sheet electrical steel. Thus, if potting material is applied to laminated stacks, stress cracks are produced at the sharp edges of the steel sheets. Another problem associated with laminated stacks is that the magnetic circuit needs air gaps which must be precisely adjusted durinq the manufacture of the coil. This adjustment of the air gaps is explained in the above-referenced House et al patent.
It, accordingly, is an object of this invention to provide an ignition coil where parts of the magnetic circuit of the coil are formed of iron powder particles that are insulated from each other by an insulating material and where the insulating material binds the particles together. Use of parts formed of iron powder particles and insulating material eliminates the design and manufacturing problems associated with steel laminations. Thus, the parts are compatible with potting material. Further, the composite iron and insulating material can be molded into various shapes. In addition, by utilizing the composite iron powder and insulating material, no air gap need be provided in the magnetic circuit that would require adjustment. Thus, the air gap is distributed throughout the magnetic circuit because individual particles of powdered iron are coated with electrical insulation. Putting it another way, the composite material has many small gaps distributed throughout the material that act like air gaps.
The U.S. patent to Hause 2,885,458 discloses an ignition coil where an annular or toroidal core is formed of an iron powder and a binder, such as phenolic which is molded to shape. This invention differs from this patent, in that among other things, the magnetic circuit is comprised of at least two parts that are arranged to facilitate assembly of the primary and secondary windings of the coil.
In the Drawings:
Figure 1 is a sectional view of an ignition coil made in accordance with this invention;
Figure 2 is an end view of a component of the ignition coil shown in Figure 1;
Figures 3 illustrates a magnetic part that can be used in place of certain of the magnetic parts shown in Figure 1;
Figure 4 is a sectional view taken along line 4-4 of Figure 3;
Figure 5 is a sectional view taken along line 5-5 of Figure 4; and Figure 6 illustrates a modified magnetic circuit for the coil of Figure 1.
Referring now to the drawings and more particularly to Figure 1, the reference numeral 10 designates a generally cup-shaped ignition coil case that is formed of a molded plastic insulating material.
Disposed within the case 10 are two generally L-shaped magnetic parts 12 and 14 that form part of the magnetic circuit for the ignition coil. These parts 12 and 14 are formed of a composite iron powder and electrical insulating material which is compression molded to the shape shown in the drawings. This material will be described in greater detail hereinafter. The parts 12 and 14 are identical and one of these parts is shown in greater detail in Figure 2. For purposes of description, it will be assumed that part 14 is shown in Figure 2. The part 14 has a rectangular hole 14A, an axially extending portion 14B that has an circular inner surface 14C and a radially extending end wall lS portion 14D. Corresponding portions of part 12 have been designated as 12A, 12B, 12C and 12D. The end faces of portions 12B and 14B are engaged along line 15. This engagement is maintained by press fitting parts 12 and 14 between inner opposed surfaces of case 10.
The ignition coil has a core member 16 that is formed of magnetic material. The core member is rectangular in cross-section to match rectangular holes 12A and 14A. The core member 16 is inserted into holes 12A and 14A during assembly of the coil and may have a press-fit with the holes. In the final assembled position of core 16, the opposite ends thereof are located respectively in holes 12A and 14A. The core member 16 magnetically connects magnetic parts 12 and 14 and it also serves as a core for the primary and secondary windings of the ignition coil.
The core member 16 can be formed from a stack of steel laminations, that is, a plurality of steel laminations. Alternatively, core member 16 could be a solid iron rod or bar. Further, core member 16 could .. .:
-:~ .
20~2485 be formed of the same material as parts 12 and 14, that is, a molded composite iron powder and insulating material.
The primary winding of the ignition coil is designated as 18. It is comprised of a number of turns of wire that are wound on and supported by a spool 20 that is formed by insulating material. The spool 20 and primary winding 18 are disposed about core 16.
The secondary winding of the ignition coil is generally designated as 22. The secondary winding is a so-called segment-wound winding si.nce it has a plurality of series-connected winding portions or sections 24 that are wound into annular grooves formed in coil spool 26. Twelve individual winding sections are shown in Figure 1. The spool 26 is formed from an electrical insulating material.
To assemble the ignition coil that has been described, one end of core 16 can be inserted into, for example, the hole 12A in part 12. A primary winding unit comprised of spool 20 and primary winding 18 carried thereby is now assembled over core 16.
Following this a secondary winding unit comprised of spool 26 and the secondary winding carried thereby is assembled over the primary winding unit. The part 14 is now assembled such that the end of core 16 is inserted into hole or opening 14A and such that end surfaces of portions 12B and 14B are in contact.
When the parts have been assembled as described, they are placed in case 10 and the parts are then encapsulated by a potting compound formed by insulating material that is designated as 28. This potting compound closes the open end of case 10. The potting compound secures the parts of the coil together and bonds to the case 10 to retain the parts of the ignition coil in case 10. Putting it another way, the potting compound fills open spaces in and around the parts of the ignition coil.
Figures 3-5 illustrate a magnetic part 30 that may be substituted for the parts 12 and 14 of the ignition coil shown in Figure 1. The part 30iS formed of magnetic material of the same type that is used for parts 12 and 14, that is, a molded composite iron powder and insulating material. Part 30 has end portions 30A and 30B joined by axially extending portion 30C. End portions 30A and 30B, respectively, have open-ended radially extending slots 30D and 30E.
The slots 30D and 30E receive the ends of a core member, like core member 16 which is press fitted to the slots. It will be appreciated that portion 30C
performs the same function as portions 12B and 14B of the arrangement shown in Figure 1.
Figure 6 illustrates another modified magnetic circuit. In Figure 6, parts 32 and 34 are substituted for parts 12, 14 and 16 of Figure 1. Coils 18 and 24 are shown diagrammatically and would have coil spools like the ones shown in Figure 1. Parts 32 and 34 are formed of the same type of magnetic material as parts 12 and 14, that is, a composite iron powder and insulating material. Part 32 has an axially extending portion 32A, the end face of which abuts or engages the end face of axially extending portion 34A of part 34.
Portions 32A and 34A correspond to portions 12B and 14B
of Figure 1 and have the same shape as these parts. In Figure 6, the core for primary winding 18 and secondary winding 22, rather than being a separate part, is formed by engaged axially extending portions 32B and 34B of parts 32 and 34. Portions 32B and 34B are integral with and extend axially from end wall portions 32C and 34C of parts 32 and 34. Portions 32B and 34B
can be square in cross-section like core member 16 or could have a circular cross-section.
As previously described, parts 12, 14, 16, 30, ; "
32 and 34 can all be formed of a composite magnetic material, that is, particles of powdered iron in a binder formed of electrical insulating material. The final compression molded product should be such that individual iron particles are coated by the insulating material. The insulating material then forms two functions, namely, it insulates particles from each other and it binds the particles together. The electrical insulating coating on and between iron particles act like many small air gaps distributed throughout the material. The gaps, of course, are not actually formed of air, but since insulating material has about the same permeability as air, an air gap effect is achieved.
This invention is not restricted to the type of iron particle powder that is used nor to the type of particle insulation that is used. The mean particle size of the iron particles may be about 0.004 inches.
One example of an iron powder is a Hoeganeas Corp.
1000B powder. This powder can be mixed with a suitable epoxy resin powder and the mixture is then compacted in a press or mold to the desired shape. The part is then cured and the resultant product is a material where the particles are insulated from each other by the epoxy insulating material which also serves to bind the particles together. The final product may have a range of about .5 to 2% by weight of epoxy material with the remainder being iron powder.
The composite material may be comprised of iron particles which are bound together and separated by a cured thermoplastic material. Thus, iron particles of a mean particle size of about 0.004 inches can be coated with a thermoplastic material. The coated particles are placed in a heated mold and then compression molded to the desired shape and density.
The final product is a composite part that is comprised :
20~2485 of cured thermoplastic material and iron particles.
The cured thermoplastic materials binds the particles together and serves to insulate a majority of the particles from each other. However, it is possible that some of the iron particles will become engaged during molding pressure but the final product has a multiplicity of gaps that act like air gaps. The final molded part, by volume, may be about 96% iron powder and about 4~ thermoplastic material.
In a conventional ignition coil design utilizing sheet metal laminations, the density of the sheet steel is a constant value. Therefore, the amount of iron designed into the circuit (to prevent saturation of the circuit with flux density) is controlled by the cross sectional area and stacking factor of the lamina. Also, the steel sheet is continuous, therefore, the air gap designed into the circuit (to control the primary inductance needed to provide the desired energy storage) is controlled by the amount that is physically cut out of the circuit.
In an ignition coil design utilizing electrically insulated iron particles, the density of the powdered metal form is variable. Therefore, the amount of iron designed into the circuit is controlled by the cross sectional area and the density attained by the powdered metal compaction process. Also, the powdered iron particles are insulated from each other by the electrical insulating coating, therefore, the air gap designed into the circuit is controlled by the number of coated powdered iron particles present in the powdered metal form and the space between them. The number of coated iron particles present and the spacing between them are determined by the length of the flux path designed in the form, the cross sectional area, and the density attained by the powdered metal compaction process.
' There is a relationship between the amount of iron and air gap present with respect to the flux density generated in the powdered metal form.
This relationship can be explained as follows. For a given ignition coil design, utilizing a known powdered metal material quantity, the quantity of iron and amount of air gap needed to provide the desired coil performance can be determined. Then, to develop the size and shape of the magnetic circuit, the cross sectional area must be made optimum. If there is not enough cross sectional area, the flux density will be too high and saturate the iron. The iron saturation will cause poor performance due to low energy transfer efficiency and high core losses. If there is too much cross sectional area, the flux density will be too low and the lines of flux will bypass the air gaps. The number of gaps present may have been sufficient to provide enough stored energy, but they were not all utilized in the magnetic circuit. Therefore, there will still be an apparent saturation of the iron and a poor performance due to low energy transfer efficiency and high core losses.
Therefore, when there is too much iron in the magnetic circuit because of too much cross sectional area, even though the cumulative air gap caused by the particle coatings and the spacing between the particles is correct with respect to the ignition coil design, the lines of flux are selective and only utilize a portion of the air gaps. This results in an undesirable situation. If the situation is over corrected by reducing the cross sectional area too much, the iron becomes saturated. This results in an undesirable situation~ The point where the iron is being fuily utilized but not saturated, and the air gaps are being fully utilized but not saturated is the design window desired for the most efficient ignition coil design utilizing electrical insulated powdered metal particles for the magnetic circuit.
To achieve optimum results, the magnetic circuit is designed in a manner that has been described with due regard to the electrical performance to be achieved by a given coil design.
Claims (7)
1. An ignition coil for developing a spark plug firing voltage comprising, first and second magnetic parts each formed of iron particles in a binder of an electrical insulating material, said insulating material interposed between said iron particles to form a plurality of gaps between the particles that operate like air gaps, said parts having respective portions that are axially spaced, an axially extending core means formed of magnetic material connected between said portions, a primary winding disposed about said core means, a secondary winding disposed about said primary winding, and axially extending means formed of magnetic material located outside of said secondary winding magnetically connecting said portions, said axially extending means extending only part way about said secondary winding in the circumferential direction.
2. The ignition coil according to claim 1 where said axially extending core means is comprised of a plurality of steel laminations.
3. The ignition coil according to claim 1 where said axially extending core means is an iron rod.
4. The ignition coil according to claim 1 said axially extending core means is comprised of the same material as said first and second parts.
5. The ignition coil according to claim 1 where said axially extending core means is comprised of engaged axially extending portions of said first and second parts.
6. The ignition coil according to claim 1 where said axially extending means that is located outside of said secondary winding is comprised of axially extending engaged portions of said first and second parts.
7. The ignition coil according to claim 1 where said axially extending means that is located outside of said secondary winding is comprised of an axially extending length of material that is of the same type as the material of said first and second parts and which is integral with said axially spaced portions of said first and second parts.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US39182089A | 1989-08-10 | 1989-08-10 | |
| US07/391,820 | 1989-08-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2012485A1 true CA2012485A1 (en) | 1991-02-10 |
Family
ID=23548079
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002012485A Abandoned CA2012485A1 (en) | 1989-08-10 | 1990-03-19 | Ignition coil |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0412679B1 (en) |
| JP (1) | JPH0821508B2 (en) |
| KR (1) | KR950015008B1 (en) |
| CN (1) | CN1020782C (en) |
| AU (1) | AU609663B2 (en) |
| BR (1) | BR9003929A (en) |
| CA (1) | CA2012485A1 (en) |
| DE (1) | DE69000381T2 (en) |
| ES (1) | ES2035710T3 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5015982A (en) * | 1989-08-10 | 1991-05-14 | General Motors Corporation | Ignition coil |
| US5241941A (en) * | 1992-09-03 | 1993-09-07 | Ford Motor Company | Ignition coil |
| DE69505092T2 (en) * | 1994-12-06 | 1999-04-22 | Denso Corp | Ignition coil for an internal combustion engine |
| JP4789452B2 (en) * | 2004-11-29 | 2011-10-12 | 京セラ株式会社 | Surface mount type coil |
| JP4209403B2 (en) * | 2005-04-12 | 2009-01-14 | 三菱電機株式会社 | Ignition device for internal combustion engine |
| US7210290B1 (en) * | 2005-11-21 | 2007-05-01 | General Motors Corporation | Reduced stall capacity torque converter |
| JP2007180296A (en) * | 2005-12-28 | 2007-07-12 | Hanshin Electric Co Ltd | Ignition coil for internal combustion engine |
| JP5991593B2 (en) * | 2013-04-10 | 2016-09-14 | ダイヤモンド電機株式会社 | Ignition coil |
| JP2020526940A (en) * | 2017-07-13 | 2020-08-31 | ダイアモンド エレクトリック マニュファクチュアリング コーポレイション | Electromagnetic devices and their thermal management |
| CN109616302A (en) * | 2018-12-19 | 2019-04-12 | 重庆奇甫机械有限责任公司 | Ignition coil |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3668589A (en) * | 1970-12-08 | 1972-06-06 | Pioneer Magnetics Inc | Low frequency magnetic core inductor structure |
| US4543208A (en) * | 1982-12-27 | 1985-09-24 | Tokyo Shibaura Denki Kabushiki Kaisha | Magnetic core and method of producing the same |
| JPS6158221A (en) * | 1984-08-29 | 1986-03-25 | Hitachi Ltd | Coil device for generating high-voltage |
| JPS61131408A (en) * | 1984-11-30 | 1986-06-19 | Toshiba Corp | Choke coil |
| NL8600771A (en) * | 1986-03-26 | 1987-10-16 | Philips Nv | APPARATUS WITH A CORE OF PARTS OF AMORF FERROMAGNETIC METAL AND PARTS OF NON-AMORF FERROMAGNETIC MATERIAL. |
| JPH088172B2 (en) * | 1986-05-09 | 1996-01-29 | 木嶋無線株式会社 | Small transformer core |
| US4647890A (en) * | 1986-05-15 | 1987-03-03 | Battelle Development Corporation | Molded ferromagnetic return circuit for a solenoid |
-
1990
- 1990-03-19 CA CA002012485A patent/CA2012485A1/en not_active Abandoned
- 1990-07-25 EP EP90308121A patent/EP0412679B1/en not_active Expired
- 1990-07-25 AU AU59855/90A patent/AU609663B2/en not_active Ceased
- 1990-07-25 DE DE9090308121T patent/DE69000381T2/en not_active Expired - Fee Related
- 1990-07-25 ES ES199090308121T patent/ES2035710T3/en not_active Expired - Lifetime
- 1990-08-09 KR KR1019900012230A patent/KR950015008B1/en not_active IP Right Cessation
- 1990-08-09 BR BR909003929A patent/BR9003929A/en not_active IP Right Cessation
- 1990-08-10 JP JP2213615A patent/JPH0821508B2/en not_active Expired - Lifetime
- 1990-08-10 CN CN90106985A patent/CN1020782C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| KR920004717A (en) | 1992-03-28 |
| JPH0388310A (en) | 1991-04-12 |
| ES2035710T3 (en) | 1993-04-16 |
| EP0412679A1 (en) | 1991-02-13 |
| CN1049394A (en) | 1991-02-20 |
| DE69000381D1 (en) | 1992-11-12 |
| AU5985590A (en) | 1991-02-14 |
| AU609663B2 (en) | 1991-05-02 |
| EP0412679B1 (en) | 1992-10-07 |
| CN1020782C (en) | 1993-05-19 |
| JPH0821508B2 (en) | 1996-03-04 |
| KR950015008B1 (en) | 1995-12-21 |
| DE69000381T2 (en) | 1993-02-11 |
| BR9003929A (en) | 1991-09-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |