WO2012062601A1

WO2012062601A1 - Ignition coil with a reduced number of components

Info

Publication number: WO2012062601A1
Application number: PCT/EP2011/068914
Authority: WO
Inventors: Konstantin Lindenthal; Florian Herzog; Kazim Kahraman
Original assignee: Robert Bosch Gmbh
Priority date: 2010-11-11
Filing date: 2011-10-27
Publication date: 2012-05-18
Also published as: CN103201802A; BR112013011396A2; DE102011083442A1; CN103201802B

Abstract

The invention relates to an ignition coil, comprising a coil former (2), a winding consisting of a winding wire (6) with a first winding region (61) and a second winding region (62), wherein the coil former (2) comprises a first cylinder section (21), onto which the first winding region (61) is wound, and a second cylinder section (22), onto which the second winding region (62) is wound, and an intermediate section (23), wherein the intermediate section (23) is arranged between the first and second cylinder sections (21, 22), and wherein the intermediate section (23) does not have a winding, and a slot-like channel (4), which runs from the intermediate section (23) up to an outer side of the second cylinder section (22), wherein the first cylinder section (21) has a continuous first cylinder lateral surface (21a), and wherein the second cylinder section (22) has a continuous second cylinder lateral surface (22a).

Description

Description title

Ignition coil with reduced number of components state of the art

The present invention relates to an ignition coil for an internal combustion engine with a reduced number of components.

Ignition coils are of the prior art in different

Embodiments known. From DE 198 50 519 A1, for example, an ignition coil is known which has a suppression element for damping the electrical interference energy which occurs during ignition of the spark plug. The suppression element is designed as an inductance in the axial direction of the ignition coil and is at least partially formed from the winding wire. However, this known ignition coil is suitable only for pencil ignition coils and not for Kompaktzündspulen. Furthermore, in the known ignition coils nowadays a Wckelanfang, the so-called cold side, and a winding end, the so-called hot side, each connected to a Anbindepfosten made of metal and welded by means of a ferrule. In addition, an additional contact plate is needed for the production of a high voltage contact between the Anbindepfosten at the coil end and a suppression resistor.

Disclosure of the invention

The ignition coil according to the invention for an internal combustion engine with the

Features of claim 1, on the other hand, has the advantage that it has a significantly reduced number of components. Furthermore, according to the invention, thermo-mechanical stresses in the ignition coil can be reduced. This has a positive effect on the service life of the ignition coil. This is inventively achieved in that the ignition coil a bobbin with a first Cylinder section and a second cylinder section has. Furthermore, the ignition coil comprises a winding, wherein a first Wckelbereich on the first cylinder portion and a second winding portion on the second

Cylinder section is wound. Between the two cylinder sections, a winding-free intermediate section is provided. The first and second

Cylinder sections are formed such that they each have a continuous cylinder jacket surface. Further, a slit-like channel is provided, which from the intermediate portion of an inner side of the second

Cylinder section to an outside reaches. Thus, according to the invention, a simple and quick Wckelvorgang can take place on the two cylinder jacket surfaces and further, the winding wire can be guided in the slot-like channel below the second Wckelbereichs. In this way, the Wckeldraht can be guided through the slot-like channel to the outside of the second Wckelbereichs and the second winding area thus be wound like the first Wckelbereich from outside to inside. As a result, in particular an ignition coil is made possible, which experiences only small thermal loads due to the geometry of the wagon, since a good thermal compensation can be obtained by arranging the windings in each case from the outside to the middle.

The dependent claims show preferred developments of the invention.

Particularly preferably, the slot-like channel is arranged parallel to a center axis of the ignition coil. As a result, a short connection is obtained from the center of the ignition coil to an axial outside.

More preferably, the high voltage outlet is preferably centered on

Spool arranged. The high voltage output is made integral with the ignition coil and projects in a pin-like manner from an outer periphery of the bobbin. By integrating the high voltage output directly to the bobbin direct contacting a spark plug on

High voltage output, so that on the hot side of the

Winding wire on a Anbindepfosten, a wire end ferrule and an additional separate high voltage contact part can be omitted. The central arrangement of the high voltage outlet is particularly suitable for Kompaktzündspulen. Preferably, the high voltage output is designed as a suppression element, in which the winding wire from the last coil chamber for

High voltage output is performed and several times around the

High voltage output is wound around. As a result, a high-voltage outlet with integrated suppressor element can be integrally formed on the bobbin.

More preferably, for a symmetrical design of the ignition coil of the first and second cylinder section are formed such that the cylinder sections in the axial direction have a same axial length. Preferably, the same cylinder sections also have a same diameter.

More preferably, the first winding region and the second Wckelbereich form a secondary winding of the ignition coil.

According to a further preferred embodiment of the present invention, the first cylinder section comprises a first outer wall region, which has a recess for the passage of the winding wire from a contact element. The first outer wall region prevents slippage of the winding from the bobbin. Particularly preferred is the

Contact element disposed directly on the first outer wall portion and formed integrally with the bobbin.

More preferably, the first cylinder portion further comprises a first inner wall portion which is disposed adjacent to the windingless intermediate portion. At the first inner wall portion, a radially outwardly projecting nose is provided, wherein the winding wire is guided around the nose and is guided over the intermediate portion to the second cylinder portion. The projecting nose thus enables a secure guidance of the winding wire during the winding process and avoids an undesirable

Slipping of the winding wire from the first inner wall portion of the first cylinder portion. Particularly preferably, the projecting nose is arranged offset in the circumferential direction to the slot-like channel. Particularly preferably, the offset of the projecting nose is such that the protruding nose begins in the circumferential direction at a height on which a

Wall of the slot-like canal lies. This ensures that at a Lead around the winding wire around the protruding nose of the winding wire also abuts an edge of the slot-like channel to the intermediate portion and thus undesirable slipping of the winding wire can be avoided.

Further preferred is at the second cylinder portion adjacent to a

Outlet region on the slot-like channel provided an undercut, through which the Wckeldraht is then guided into the second cylinder section. This also avoids undesirable slipping of the Wckeldrahts.

drawing

Hereinafter, an embodiment of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:

Figure 1 is a schematic radial side view of an ignition coil

according to an embodiment of the invention,

FIG. 2 shows an axial side view of the ignition coil of FIG. 1,

FIG. 3 is a perspective view of the ignition coil of FIG. 1;

Figure 4 is a radial side view of the ignition coil, wherein the guidance of the Wckeldrahts is illustrated in the ignition coil, and

Figure 5 is a radial side view of the ignition coil with wound

Winding wire.

Preferred embodiment of the invention

Hereinafter, an ignition coil 1 according to a preferred embodiment of the invention will be described in detail with reference to Figures 1 to 5.

The ignition coil has a bobbin 2 and a Wcklung of a

Winding wire 6, wherein the winding has a first winding portion 61 and a second winding portion 62. The bobbin 2 has a first Cylinder portion 21, on which the first winding portion 61 is wound, and a second cylinder portion 22, on which the second winding portion 62 is wound, and an intermediate portion 23. The intermediate portion 23 is disposed between the first and second cylinder portion 21, 22 and has no winding on.

The bobbin 2 comprises three main areas, namely the first one

Cylinder portion 21, the second cylinder portion 22 and the

Intermediate section 23. The first and second cylinder sections 21, 22 each have according to the embodiment in the axial direction X-X of the bobbin

2 seen an equal axial length. The intermediate portion 23 is significantly shorter in the axial direction. The two cylinder sections 21, 22 also have the same diameter. The first cylinder portion 21 has a length L1 in the axial direction which is the same length as a length L2 of the second cylinder portion 22 in the axial direction. In this way, a symmetrical bobbin structure can be achieved and the two Wckelbereiche on the first and second cylinder section 21, 22 are formed the same size.

On the first cylinder portion 21, a first outer wall portion 24 and a first inner wall portion 25 are further formed, which is a continuous

Limit cylinder surface of the first cylinder portion 21 and form a first receptacle for the first winding portion 61 of the winding. The second cylinder portion 22 includes a second outer wall portion 26 and a second inner wall portion 27, which is also a continuous one

Limit cylinder jacket surface 22a and form a second receptacle for the second winding portion 62 of Wcklung. The winding is, for example, a secondary winding. Further, in the second cylinder portion 22, a channel 4 is formed, which extends from the intermediate portion 23 to the axial outside of the second cylinder portion 22. As can be seen in FIG. 1, the channel 4 is arranged parallel to the central axis X-X of the bobbin 2. Of course, the channel 4 can also obliquely to the central axis X-X of the

Bobbin 2 run. The channel 4 serves to guide a winding wire 6 of the winding under the second Wckelbereich 62 of Wcklung.

As a result, the Wckeldraht from the first Wckelbereich 61 starting over the intermediate portion 23 are guided by the channel 4 to the outside of the second winding portion 62 and the second winding portion 62 thus be wound like the first Wckelbereich 61 from outside to inside. The part of the winding wire, which is guided under the second Wckelabschnitt 62, located outside of the channel 4 on the side facing away from the winding of the

Bobbin 2 on.

Radially within the cylinder sections 21, 22 of the bobbin 2, a further cylinder section is arranged, which is connected in one piece with the cylinder sections 21, 22 of the bobbin 2 via webs extending in the radial direction. In the radial direction between the cylinder sections 21, 22 and the further cylinder section, a distance is provided. The

Cylinder sections 21, 22 and the further cylinder section are arranged concentrically, for example. On the further cylinder section, a further winding, for example a primary winding, is arranged.

The channel 4 is designed, for example, as a slot extending in the bobbin 2 from the intermediate portion 23 to the axial outside of the second cylinder portion 22. The slot 4 also passes through the second inner wall portion 27, whereby this slit at one point

is severed. The slot 4 extends in the radial direction through the material of the cylinder portion 22 completely therethrough. The slot 4 has in the region of the intermediate portion 23 extending in the circumferential direction undercut, whereby the Wckeldraht can create outside the slot 4 to the Wckelbereich 62 facing away from the inner wall of the bobbin 2.

As can be seen in particular from Figures 1 to 3, is on the

Bobbin 2 a receptacle 3 for a contact element and a

High voltage outlet 5 arranged. The high voltage outlet 5 is on

Spool 2 executed in the intermediate portion 23, which corresponds for example to the center of the bobbin 2.

Figure 4 shows schematically how the Wckeldraht 6 is guided on the bobbin 2, to the bobbin 2, a first Wckelbereich 61 and a second

To provide winding area 62 (see Figure 5). Starting from the contact part 3 is the winding wire 6 through a recess 9 on the first

Cylinder section 21 out and wound there along a first continuous cylinder jacket surface 21 a to the first inner wall portion 25. At the first inner wall portion 25, a radially projecting nose 7 is provided, wherein the winding wire 6 is guided around the nose 7 around and is guided transversely to the intermediate region 23 in the slot-like channel 4. Here, the Wckeldraht 6 is located at an edge 10, which at the mouth of the

slit-like channel 4 to the intermediate portion 23 is formed. The winding wire 6 is then guided in the axial direction along the channel 4 and guided at the outlet of the channel 4 from the second cylinder portion 22 via an undercut 8 on the second outer wall portion 26 to the second cylinder portion 22. The undercut 8 may also be a projecting post or a protruding nose. At the second cylinder portion 22 is then the

Winding wire 6 from the outside, that is, from the second outer wall portion 26 to the second inner wall portion 27 on a second continuous

Coiled cylindrical surface 22a, wherein the winding wire 6 is wound over the slot-like channel 4 respectively. When the second cylinder portion 22 has been completely wound, the beak wire 6 is then guided from the second inner wall portion 27 to the high voltage output 5 and wound around the high voltage output 5 several times to form a suppression element.

Thus, according to the invention, an ignition coil 1 can be provided in which a primary winding on the further cylinder section and a secondary winding on the cylinder sections 21, 22 are provided.

In this case, the two cylinder sections 21, 22 are formed with Zylinderflächenmänteln 21 a, 22 a, which can be made particularly simple and which simplify a Wcklung the ignition coil. Furthermore, the

Ignition coil according to the invention on thermomechanical advantages, since the hot winding outlet is located in the middle of the ignition coil. Thus, a uniform heat distribution at the ignition coil can be obtained. Furthermore, at both cylinder sections 21, 22, the two Wcklungsbereiche 61, 62 are each wound from outside to inside. As can be seen in particular from FIG. 1, the radially projecting nose 7 is arranged offset in the circumferential direction to the slot-like channel 4. The protruding nose 7 begins in

Circumferential direction immediately adjacent to the channel 4, whereby that the winding wire 6 abuts both around the nose 7 and around the edge 10 at the channel entrance, starting from the intermediate section 23 forth.

Thus, according to the invention, a number of components, in particular at the hot end in the region of the high-voltage outlet 5 in comparison with the prior

Technology can be significantly reduced. It is both the production of the

Spool 2 significantly simplified as well as the winding process on the bobbin 2, since the Wcklungen each in one step on the

continuous cylinder jacket surfaces 21 a, 22 a can be wound. Since the axial lengths L1 and L2 of the first and second cylinder sections 21, 22 are the same, the result is a symmetrical construction of the coil body with a central high-voltage outlet 5. The ignition coil according to the invention is particularly preferably suitable for compact ignition coils.

Claims

Ignition coil, comprising:

a bobbin (2)

a winding of a winding wire (6) with a first

Winding area (61) and a second winding area (62), wherein the bobbin (2) has a first cylinder portion (21) on which the first Wckelbereich (61) is wound, and a second

Cylinder portion (22) on which the second Wckelbereich (62) is wound, and an intermediate portion (23), wherein the

Intermediate section (23) between the first and second

Cylinder section (21, 22) is arranged and wherein the

Intermediate section (23) has no winding, and

a slit-like passage (4) extending from the intermediate portion (23) to an outer side of the second cylinder portion (22),

Ignition coil according to claim 1, characterized in that the slot-like channel (4) is parallel or oblique to a central axis (X-X) of the bobbin (2).

Ignition coil according to one of the preceding claims, characterized in that a high-voltage outlet (5) is arranged on the intermediate section (23) of the coil former (2).

Ignition coil according to one of the preceding claims, characterized in that an axial length (L1) of the first cylinder portion (21) is equal to an axial length (L2) of the second cylinder portion (22).

5. Ignition coil according to one of the preceding claims, characterized

in that a suppression element is formed on the high-voltage outlet (5), wherein the interference suppression element comprises several around a core of the High voltage output (5) wound windings of the

Winding wire (6).

6. Ignition coil according to one of the preceding claims, characterized

characterized in that the first winding region (61) and the second winding region (62) form a secondary winding of the ignition coil.

7. Ignition coil according to one of the preceding claims, characterized

in that the first cylinder section (21) has a first outer wall region (24) which has a recess (9) for passing through the winding wire to form a contact element.

8. Ignition coil according to claim 7, characterized in that on

Spool (2) is provided a receptacle (3) for the contact element.

9. Ignition coil according to one of the preceding claims, characterized

characterized in that the first cylinder portion (21) comprises a first inner wall portion (25) on which a radially outward

protruding nose (7) is provided, wherein the winding wire (6) is guided around the nose (7) and guided by the nose (7) in the slot-like channel (4).

10. Ignition coil according to claim 9, characterized in that the after

outside projecting nose (7) in the circumferential direction offset from the slot-like channel (4) is arranged.