CN1049394A

CN1049394A - Spark coil

Info

Publication number: CN1049394A
Application number: CN90106985A
Authority: CN
Inventors: 杰克·卢曼·菲利普斯; 罗杰·韦斯利·凯蓝斯; 朗纳利·豪斯
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1989-08-10
Filing date: 1990-08-10
Publication date: 1991-02-20
Anticipated expiration: 2005-08-10
Also published as: KR920004717A; EP0412679A1; ES2035710T3; JPH0388310A; KR950015008B1; JPH0821508B2; AU5985590A; CN1020782C; DE69000381D1; BR9003929A; EP0412679B1; AU609663B2; DE69000381T2; CA2012485A1

Abstract

One for improving the spark coil of plug ignition current potential.This spark coil contains first and second parts (12,14), and they are by (12D, the iron particle in electrically insulating material adhesive 14D) constitutes in the endwall part of having determined axially to be spaced.These two-part are connected by the magnetic core element (16) that is made of magnetic material.Elementary winding (18) is configured around magnetic core element, and secondary windings (22) is configured around primary air.(12B 14B) is positioned at secondary windings outside and be connected with endwall part magnetic to the part that extends axially that is made of magnetic material.

Description

Spark coil

The present invention relates to spark coil, more specifically to a kind of like this spark coil, the magnetic circuit that wherein is used for spark coil is made up of Powdered iron particle, the electrically insulating material that these particles are formed its adhesive surrounds, and this insulating material makes these iron particle electrically insulated from one another and form the insulation space between iron particle.

Spark coil often uses the lamination steel as the magnetic circuit that is used for the primary and secondary winding.At U. S. Patent 4,480, this example is disclosed in 377.But use the steel lamination layer that unfavorable factor is arranged.Like this, use the steel lamination layer to cause the restriction of plug-in unit aspect size and dimension that designs.In addition, it is incompatible with the thin slice electric steel to be used for the potting material of spark coil.So if potting material is added on the lamination, the place can produce stress crack in the steel disc sharp edges.Another problem relevant with lamination is that magnetic circuit requires must accurately adjust air gap in spark coil is made.Being adjusted in the above referenced U. S. Patent of this air gap lays down a definition.

Spark coil according to the present invention contains: the magnetic core arrangement that extends axially and be made of magnetic material; The elementary winding of wounded core device configuration; Secondary windings around elementary winding configuration, the endwall part that constitutes by iron particle in the electrically insulating material adhesive, this electrically insulating material is placed between iron particle to form many gaps as between the iron particle of air gap effect, endwall part by the magnetic core arrangement axially-spaced be connected, and be connected with endwall part magnetic be positioned at the secondary windings outside extend axially device by what magnetic material constituted, this extends axially device and extends around the part passage of secondary windings circumferencial direction.

Therefore, an object of the present invention is to provide a kind of spark coil, its magnetic circuit component is by forming with the iron particle of electrically insulating material mutually insulated, and described electrically insulating material with the iron particle gluing together.The parts that use is made by iron particle and electrically insulating material have been eliminated design and the production problem relevant with the steel lamination.Therefore, this magnetic part can be compatible with potting material.And the iron particle of mixing can mold pressing form different shapes with electrically insulating material.In addition, by using iron particle and the electrically insulating material that mixes, need in magnetic circuit, not provide the air gap that requires adjustment.Like this, because the single particle of iron powder surrounded by electrically insulating material, so air gap is distributed in the whole magnetic circuit.Change a kind of saying, this blending material has the little gap of the effect of much being distributed in the whole material as air gap.

U. S. Patent 2,885,458 disclose a kind of like this spark coil, wherein toroidal core is made of the such adhesive of the phenolic aldehyde of iron powder and moldable moulding, and this arrangement is different from part of the present invention and is: wherein this magnetic circuit is convenient to assemble by elementary winding that is used to make spark coil and secondary windings and two-part of arranging are formed at least.

The present invention now will be described with reference to following introduction and accompanying drawing by example, in the accompanying drawing:

Fig. 1 is a spark coil sectional view constructed in accordance;

Fig. 2 is the part end elevation of the spark coil shown in Fig. 1;

Fig. 3 illustrates a magnetic part that can be used to replace certain magnetic part shown in Figure 1;

Fig. 4 is the sectional view that the 4-4 hatching line obtains in Fig. 3;

Fig. 5 is the sectional view that the 5-5 hatching line obtains in Fig. 4;

Fig. 6 illustrates an improvement magnetic circuit that is used for Fig. 1 spark coil.

Referring now to accompanying drawing Fig. 1 particularly, label 10 is specified (normally cup type) housing, and it is made of the plastic insulation material of compression molding.Being arranged in the housing 10 is two (normally L type) magnetic parts 12 and 14, and their form the part magnetic circuit that is used for spark coil.These magnetic parts 12 and 14 are made up of the iron powder and the electrically insulating material that mix, and this electrically insulating material is moulded to shape as shown in drawings.Hereinafter this blending material will be described in more detail.Magnetic part 12 and 14 is the same, and one of them is shown in more detail among Fig. 2.For the purpose of illustrating, suppose it is magnetic part 14 shown in figure 2.Magnetic part 14 has a rectangular opening 14A, the endwall part 14D who extends axially part 14B and radially extend with annular inner surface 14C.The corresponding part of magnetic part 12 is designated as 12A, 12B, 12C and 12D.Thereby coupling together, the end face that extends axially part 12B and 14B along the line 15 determined to extend axially device.Keeping this by the magnetic part 12 and 14 between compression fit housing 10 interior surface opposing is connected.

Spark coil has a magnetic core element 16 that is made of magnetic material.The cross section of magnetic core element 16 be rectangle so that and rectangular opening 12A and 14A be complementary.Magnetic core element 16 is inserted among rectangular opening 12A and the 14A when the assembling spark coil, and with rectangular opening one compression fit is arranged.In the last mounting point of magnetic core element 16, its opposite end lays respectively among rectangular opening 12A and the 14A.Magnetic core element 16 links to each other with 14 magnetic with magnetic part 12, and also is used as the magnetic core or the magnetic core arrangement of spark coil primary and

secondary winding

18,22.

Magnetic core element 16 can be by a laminated steel sheet, and promptly many steel discs constitute.Perhaps, magnetic core element 16 can be made up of solid iron bar or iron staff.In addition, magnetic core element 16 can be used and magnetic part 12 and 14 the same materials, i.e. the iron powder of compression molding and the mixture of electrically insulating material constitute.

The elementary winding of spark coil is appointed as 18.It is supported by roll 20 and winding a lot of circle leads are thereon formed, and roll is made of insulating material.Roll 20 and elementary winding are around magnetic core element 16 configurations.

What the secondary windings of spark coil was total is designated as 22.Because the series winding part 24 in many circular grooves that are wrapped in the roll 26 is arranged, so secondary windings is the winding that so-called segmentation is twined.Fig. 1 illustrates 12 independent winding segments.Roll 26 is made of electrically insulating material.

Be the spark coil described of assembling, an end of magnetic core element 16 can be injected, for example, among the rectangular opening 12A of magnetic part 12.Therefore be installed on the magnetic core element 16 by roll 20 with around the first level assembly that elementary winding 18 is thereon formed.Subsequently, the secondary windings assembly of being made up of roll 26 and the secondary windings 22 that is equipped with on it is installed on the elementary winding assembly thus.So magnetic part 14 is so assembled: an end that is about to magnetic core element 16 inserts among the rectangular opening 14A, and the end face that extends axially part 12B and 14B is kept in touch.

When various parts assemble by described mode, they are put into housing 10, then the seal apparatus compound sealing of forming by the insulating material of being appointed as 28.The opening end of these potting compound 28 enclosing housings 10, this potting compound the each several part of spark coil is fixed together and with the bonding each several part with the holding point fire coil of housing 10 in housing 10.In other words, potting compound 28 is filled each void space and is centered on the spark coil each several part.

Fig. 3-5 explanation can replace the magnetic part 12 of spark coil illustrated in fig. 1 and a magnetic part 30 of 14.Magnetic part 30 is by the same magnetic material that is used for magnetic part 12 and 14, i.e. the iron powder of compression molding and the mixture of electrically insulating material constitute.Magnetic part 30 has by extending axially endwall part 30A and the 30B that part 30C connects.Endwall

part

30A and 30B have (worn-out mouthful of end radially extends), grooving 30D and 30E respectively.Grooving 30D admits as the two ends of compression fit to the magnetic core element of the magnetic core element 16 of grooving with 30E.To propose below, and extend axially part 30C and carry out and extend axially part 12B and the same function of 14B shown in Fig. 1, therefore determine to extend axially device.

Fig. 6 illustrates another kind of improved magnetic circuit.In Fig. 6, magnetic part 12,14 and magnetic core element 16 in magnetic part 32 and 34 alternate figures 1.Schematically show with primary and

secondary winding

18 and 22, and have and resemble roll shown in Figure 1.Magnetic part 32 is that the mixture of iron powder particle and electrically insulating material constitutes with 34 by the magnetic material the same with magnetic part 12 and 14.Magnetic part 32 has one to extend axially part 32A, the end face that extends axially parts 34A of its end face and parts 34 near or be connected.Extend axially

part

32A and 34A has and 12B and the same shape of 14B with axially extension 12B and 14B are corresponding among Fig. 1, thereby determine axial epitaxial apparatus.In Fig. 6, the magnetic core (not being an individual components) that is used for elementary winding 18 and secondary windings 22 by the magnetic part 32 that is connected and 34 extend axially

part

32B and 34B constitutes.Extending axially the endwall part 32C of

part

32B and 34B and

magnetic part

32 and 34 and 34C fuses and extends axially from it.Extend axially part 32B and can be the rectangular cross-section as magnetic core element 16, also can have circular cross-section with 34B.

As previously mentioned, magnetic part 12,14,16,30,32 and 34 can be made of a mictomagnetism material, and promptly the iron particles in the binder of being made up of electrically insulating material constitutes.The product of final compression molding should be done like this, and promptly iron particle is surrounded by electrically insulating material separately.This insulating material plays two effects,, has not only made iron particle mutually insulated but also iron particle is glued together that is.Be enclosed in around the iron particle with therebetween electrically insulating material effect and be distributed in the whole blending material as many air gaps.This gap of course not really is made up of air, but because insulating material has the permeability roughly the same with air, so can obtain the effect of air gap.

The invention is not restricted to the type of used iron particle powder, also be not limited to used insulating particle type.The average particle size particle size of iron particle can be about the 0.1mm(0.0004 inch).An example of iron powder is Hoeganeas Corp.The 1000B powder of producing, this iron powder can mix with suitable epoxy powder, is desirable shape with this mixture die forming then.Then profiled part is handled, synthetic goods are a kind of materials that make the iron particle mutually insulated and be bonded together by epoxy resin insulation material.Last goods resene material can account for the 0.5%-2% of weight, and remaining part is an iron particle.

This blending material can be made up of treated thermoplastic cement material bonding and the iron particle of separating.Like this, average particle size particle size is the 0.1mm(0.004 inch) iron particle can be coated by the thermoplastic material, be placed in the heating model by the particle that coated and be moulded to desirable shape and density then.End product is to comprise the thermoplastic cement material handled and the combiner of iron particle.Treated thermoplastic cement material is glued together and make most of abrasive grit mutually insulated with iron particle.Yet, some iron particles are linked together, but end product has many gaps of playing as the air gap effect.Last moulded parts can be the thermoplastic cement material that accounts for the iron particle of volume 96% and account for volume 4%.

In the conventional point fire coil design of using metallic laminations, steel-sheet density is a steady state value.Therefore, the quantity of the iron of design in magnetic circuit (saturated for avoiding the magnetic circuit specific discharge) is controlled by the long-pending and laminated factor in mode cross section of lamination.In addition, because sheet metal is continuously continuously, therefore, the air gap of design in magnetic circuit (provides desirable energy to store needed elementary winding inductance to be controlled by the number of times that physically cuts off magnetic circuit to be controlled to be.In the spark coil of the iron particle that uses electrical insulation, the density of metallic dust moulding is variable.Therefore, the quantity of the iron of design in magnetic circuit is controlled by cross-section area and the density that obtains in the metallic dust mold process.In addition, the iron powder particle is by the electric insulation coating layer mutually insulated, and therefore, the air gap of design in magnetic circuit controlled by appearing in the shaping of metal powders cated iron particles number and the space between them.Cated iron particles number that occurs and the space between them are by determining at magnetic flux path length set under this form, cross-section area and the density that obtains in the metal powder mold process.

For the Magnetic flux density that in the metallic dust moulding, produces, between the quantity of the iron that occurs and air gap, a relation is arranged.This relation can be explained as follows.Spark coil design for given use dose known amounts granulated metal material can determine to be the quantity of the required iron of the spark coil performance that hope is provided and the quantity of air gap.Then, for improving the size and dimension of magnetic circuit, must make that sectional area is optimum.If there are not enough sectional areas, Magnetic flux density can be too high and makes iron saturated.Since low energy conversion efficiency and high core loss, the saturated performance that will cause difference of iron.If cross-section area is too big, Magnetic flux density can be too low and magnetic flux line can cross air gap.The gap that occurs may be enough to the storing energy that provides enough, but they do not have whole usefulness in this magnetic circuit.Therefore, still can cause that tangible iron is saturated owing to low energy conversion efficiency and high core loss, and bad characteristic.

Therefore, when because too big cross-section area when too many iron is arranged in magnetic circuit, even additive air crack that is caused by the iron particle coating and the space between iron particle are correct for the design of spark coil, magnetic flux line selectively only uses the part air gap.This causes a kind of undesirable state.If the cross-section area of gold makes this state overcorrect by reducing too, it is saturated that iron becomes, and this causes a kind of undesirable state again.The main points that make the spark coil that utilizes magnetic circuit electrical insulation powdered metal particle have the design window that requires of maximal efficiency are that iron is utilized fully but unsaturated, and air gap is utilized fully but be unsaturated.

Be to obtain optimum, design this magnetic circuit with the method for the described electric properties that with due regard to obtain by a given spark coil design.

Please note our number of patent application of applying on the same day with the application (MJD/3335).

Claims

1, a kind of spark coil, it contains: be made of and axially extended magnetic core arrangement (16) electromagnetic material, around the elementary winding (18) of magnetic core arrangement configuration and the secondary winding (22) that disposes around elementary winding, it is characterized in that: endwall part (12D, 14D) constitute by the iron particle in the adhesive of electrically insulating material, this electrically insulating material get involved between iron particle and betwixt the formation effect as many gaps of air gap, endwall part by the magnetic core arrangement axially-spaced be connected, and by constituting by magnetic material, what be positioned at that secondary windings outside is connected with endwall part magnetic extends axially device (12B, 14B), extending axially device only extends around the part passage of secondary windings circumferencial direction.

2, according to the spark coil of claim 1, it is characterized in that: magnetic core arrangement (16) is made up of many steel laminations.

3, according to the spark coil of claim 1, it is characterized in that: magnetic core arrangement is an iron staff.

4, according to the spark coil of claim 1, it is characterized in that: (32B is 34B) by (32C, 34C) same material is formed with the endwall part for magnetic core arrangement.

5, according to the spark coil of claim 1, it is characterized in that: (32C, (32B 32B) forms the part that extends axially that is connecting 34C) magnetic core arrangement by the endwall part.

6, according to each the spark coil in the claim 1 to 5, it is characterized in that: what be positioned at secondary windings (22) outside extends axially device by endwall part (12D, 14D, 32C, axle 34C) is with extending attachment portion (12B, 14B, 32A 34A) forms.

7, according to each the spark coil in the claim 1 to 5, it is characterized in that: what be positioned at secondary windings (22) outside extends axially device by (30A, 30B) one of the material of same-type section extends axially length 30C composition with the endwall part that fuses.