WO2013057266A1

WO2013057266A1 - High voltage transformer and wound coil former for ignition modules with terminal pins integral to the primary winding

Info

Publication number: WO2013057266A1
Application number: PCT/EP2012/070782
Authority: WO
Inventors: Roman Schichl
Original assignee: SUMIDA Components & Modules GmbH
Priority date: 2011-10-21
Filing date: 2012-10-19
Publication date: 2013-04-25
Also published as: DE112012001701A5; DE202011051721U1; DE202012102624U1

Abstract

A wound coil former for an ignition transformer, such as is used for example in discharge lamps for automobiles, etc., having a primary winding in the form of a wire in conjunction with a conductor bar which is fed through the coil former. In this way, it is possible to achieve a high dielectric strength, while at the same time the required length of wire can be reduced.

Description

High voltage transformer and wound bobbin for ignition modules with pins as part of the primary winding

The present invention relates generally to inductive components in the form of transformers, and the like, and more particularly relates to small size transformers suitable for ignition modules for providing ignition voltages of several 10,000 volts.

Inductive components, such as transformers and corresponding components for their production are required in many technical fields, especially since the use of switched power supplies for various electrical consumers increasingly important. When constructing appropriate power supplies for specific applications, a large number of sometimes contradictory requirements must be met as a rule. For example, the corresponding inductive components, such as transformers are to be produced with the least possible volume of construction, but at the same time sufficient isolation distances are provided, especially when high-voltage applications are considered. Furthermore, in many applications, a reliable operation of the components under demanding environmental conditions must be ensured, as is the case, for example, in automotive applications, where the corresponding components are in an extended temperature range with corresponding environmental influences such as snow, rain, moisture, and the like Environment are to be operated with a high Störwellenaussendung. Furthermore, economic aspects are also of particular importance, since inductive components can represent components that are complex to manufacture and process, and that can only be integrated to a very limited extent into corresponding integrated circuits. It is therefore of particular importance to be able to produce corresponding inductive components, such as transformers, and the like in a manner that is as automated as possible using inexpensive raw materials, with corresponding specifications with regard to the size, the component tolerances and the insulation resistance to be observed.

Typically, an inductive component in the form of a transformer comprises a suitably designed magnetic core, to which appropriate windings are suitably applied. In order to ensure a high degree of automation and reliability, a so-called bobbin is typically provided, is made of a suitable insulating material and provides the corresponding winding space for the windings to be received in a defined manner, so that the wound bobbin can then be connected to the core, to finally form the inductive component. When applying two or more windings on the bobbin must be made depending on the application of the transformer sufficient insulation between the individual windings, which typically takes place by appropriate insulation of the winding wires and / or by appropriate insulating materials between the individual layers in multi-layer windings. Frequently, during operation, the individual windings are at very different potentials, so that, in particular with regard to the dielectric strength, sufficient insulation distances between the individual windings or windings are to be maintained. This is especially true for ignition transformers for discharge lamps, in which a high ignition voltage of 20,000 volts or significantly higher is required to ignite the discharge in the corresponding discharge piston. In this case, an ignition transformer is preferably used in which a primary winding is driven with a small number of turns via a corresponding discharge capacitor, so that then generates the correspondingly high ignition voltage in a secondary winding and is delivered to the discharge lamp. Since in this case the primary winding is at a potential of a few 100 volts, a corresponding matched insulation between the primary winding and the secondary winding is required in order to generate any undesirable voltage flashovers.

Further, since in these applications, a compact volume of the corresponding ignition transformer is required, nevertheless, the primary winding and the secondary winding must be placed in the narrowest spaces in a bobbin, so that in particular for the primary winding with the few turns usually a corresponding winding wire with a complex insulation be provided in order to ensure the required dielectric strength. Frequently, the primary winding is wound onto the secondary winding, in which case the insulation of the primary winding, in cooperation with the insulation of the secondary winding, provides the required dielectric strength. In this case, however, a corresponding winding wire is provided at least for the primary winding, which has a high insulation resistance, in order to ensure the dielectric strength. However, these winding wires with a designed for such high voltages insulation are extremely expensive components, so that in particular in the production of high voltage resistant conductor for the primary winding is a significant cost factor of the entire transformer. In view of the situation described above, it is an object of the present invention to provide means for more efficiently providing one or more windings in a high withstand voltage inductive device.

In order to achieve the above object, the present invention provides a wound coil bobbin and a transformer, the cost being lower particularly for achieving a desired high insulation strength by providing a part of at least one turn of the winding in the form of a conductor bar in the coil bobbin. For this purpose, according to the invention, the conductor bar, which has a pin for contacting the wound bobbin with a circuit carrier, used as part of a turn of the winding, so that, for example, with a simplified manufacturing effort results in excellent insulation and also the length of the expensive insulated conductor is reduced.

In accordance with one aspect of the present invention, a wound coil body for a transformer is provided in this regard. The wound bobbin comprises a plurality of winding chambers, which are separated on a base body by partitions. Furthermore, a first winding is provided, which is applied in the plurality of winding chambers on the base body. A second winding having one or more turns of a conductor, preferably an insulated conductor, is also provided on the wound bobbin, the conductor of at least one of the one or more turns at least partially guided in recesses formed in the partitions. Furthermore, the wound bobbin comprises a conductor pin provided with a pin, which is guided in one of the partitions and forms at least part of a turn of the second winding.

Thus, according to the invention, the conductor bar is suitably designed so that on the one hand it establishes a connection to a rack and on the other hand serves as a part of the second winding, which is designed, for example, as a primary winding of a high-voltage transformer. Furthermore, results from the present in the partitions recesses a suitable guide for the conductor, so that even during the winding process as well as thereafter increased mechanical stability results, whereby the recesses amount to an even higher insulation strength of the conductor with respect to the first winding , In a further advantageous embodiment, the conductor bracket has a connection pin for connection to the conductor. In this advantageous embodiment, therefore, the conductor bracket can also be suitably used to serve as a connecting element to the conductor, so that the conductor can be connected in simple and well-established manufacturing steps with the terminal pin, for example by soldering, welding, and the like. The connection pin is correspondingly sufficiently far away from other areas, so that, for example, after casting the wound bobbin, a sufficient insulation strength results. On the other hand, the conductor bracket can be arranged in a suitable manner in the bobbin, for example by a recess of any desired cross-section, so that there is a high mechanical and electrical integrity for this area by design-related measures, ie by a suitable design form of the bobbin.

In an advantageous embodiment, a second pin is provided in one of the partitions and connected to one end of the second winding. In this way, a contacting of a printed circuit board is made possible, wherein the connecting pin and the second pin are provided in a desired geometric arrangement to each other, so that there is a simple connection diagram on the circuit board and / or a desired mechanical stability after attaching the transformer in the circuit board results.

In an advantageous embodiment of the second pin is provided in the same partition, in which also the pin of the guide bow is guided. That is, in this case, the terminal pins are arranged substantially at the same height with respect to the longitudinal direction of the bobbin, so that a very compact arrangement for the pin assignment on a printed circuit board is achieved. In further embodiments, the second pin is provided as part of a second conductor ledge which is suitably guided in a further partition so that the terminal pin of the conductor bow represents one end of the second winding and the second pin of the second conductor bow represents the other end of the second winding.

In a further embodiment, the conductor bracket has a connection pin for coupling one end of the first winding. Such a training is advantageous when the first winding and the second winding have a common node, which can thus be reliably provided on the basis of the connecting pin in a mechanically precisely defined manner.

In one embodiment, the second winding, which may serve as a primary winding, has less than 5 turns. For example, the wound coil bobbin according to the invention can be used efficiently in ignition modules for discharge lamps in motor vehicles or other mobile applications, in which a high ignition voltage with high reliability is required due to the demanding environmental conditions. In many of these applications, the high output voltages of 20,000 volts or more can only be achieved by having the number of turns of the primary winding less than 5, for example 3 turns or less. In this case, there is a significant reduction in the material cost of the insulated conductor, since with such a low number of turns, replacing at least a portion of a single turn already significantly contributes to a reduction in the overall length of the expensive insulated conductor required. The bobbin according to the invention can be provided, for example, with a length of less than 4 cm, so that results in a very compact design and replacing a turn of a few turns is a significant contribution to reducing the total cost, as for example for ignition modules of discharge lamps in Automobiles or other mobile applications is an important criterion for commercial success.

In some embodiments, the bobbin is suitable for receiving generally a longitudinal core, but this need not be rectilinear, but may also have a curved shape.

In a further embodiment, the conductor bow is inserted into the dividing wall, so that therefore a simple assembly is possible, whereby nevertheless a high degree of precision and stability is ensured. An additional mechanical fixation can for example be done later, when the bobbin is cast together with a suitable core if necessary.

According to a further aspect of the present invention, the aforementioned object is achieved by a transformer having a wound bobbin according to one of the preceding embodiments, wherein additionally provided by the bobbin longitudinal core is provided. Also in this case applies Reason of advantageous embodiment of the wound bobbin, that results in a small volume of construction in the required insulation, but the proportion of expensive conductor material can be reduced with elaborate insulating material. The transformer according to the invention is additionally embedded in potting compound, so that overall the mechanical and electrical properties can be improved thereby, wherein due to the provision of a conductor with high insulation resistance in conjunction with a realized through the pins turn overall reduced costs are achieved.

Further advantageous embodiments are described in the further claims and will become apparent from the following detailed description.

The present invention will now be described in more detail with reference to the accompanying drawings, in which:

Fig. 1 a shows schematically a side view of a wound bobbin according to the invention, wherein a conductor bar with a terminal pin forms part of a turn of a primary winding,

1 b schematically shows a top view of a conductor bar with a connection pin and a connection pin and a connection pin for connection to the primary winding and the secondary winding according to an embodiment,

1 c schematically shows a plan view of the connection side of the wound bobbin according to the invention,

Fig. 1 d schematically shows a plan view of the bobbin according to illustrative embodiments, in which the conductor bar has a greater width in the width direction of the bobbin and

Fig. 1 e schematically shows a side view of a high voltage transformer having a wound bobbin with a conductor bar with pin forming part of a primary winding.

FIG. 1 a schematically illustrates a side view of a wound bobbin 100 in accordance with illustrative embodiments of the present invention. As shown, Grasps the wound bobbin 100 a base body 1 10, which is made as a plastic material by known methods, in which a plurality of winding chambers 1 1 1 are provided. In the example shown are winding chambers 1 1 1 a, 1 1 1 b, 1 1 1 c, 1 1 1 d formed to receive a secondary winding 120, ie, a winding having a relatively large number of turns to from a relative low input voltage to produce a suitable high output voltage, for example in the range of 20,000 volts or more. The individual winding chambers 1 1 1 a, 1 1 1 d are separated by corresponding partitions 1 12a, 1 12b, 1 12c, said partitions 1 12a, 1 12c suitable incisions (not shown) in which the wire of the winding 120 to a respective adjacent chamber is guided. At least some of the partitions 112a, 112b have suitable recesses 13 dimensioned to receive a conductor or wire 131 of a second coil 130 having insulation when needed. In the example shown, the second winding is a primary winding. In the embodiment shown, the recesses 1 13 are dimensioned so that the conductor 131 is surrounded by material of the partitions 1 12 almost from three sides. In other embodiments, such three-sided confinement may not be required, as the conductor 131 has suitable high voltage insulation, thus providing the required insulation resistance. In this case, the recesses 1 13 are provided only for mechanical fixation and guidance of the conductor 131.

Further, at least one of the partitions 1 12, such as the partition wall 1 12c is provided so that in this a guide bracket 135, at least partially guided, which has a connection pin 135A. The terminal pin 135a is designed to be connected to a group of components such as a printed circuit board and the like, the conductor bracket 135 thus functions as part of the winding 130 and thus allows a significant reduction in the overall length of the conductor 131, while the terminal pin 135a of the conductor bracket 135 allows a reliable connection with a circuit board and the like. D. h., In the illustrated embodiment, the winding 130 is essentially composed of three windings, which is provided in the form of the conductor wire 131 in the partitions 1 12 a, 1 12 b and in the form of the guide bow 135 in the partition wall 1 12 c. D. h., In contrast to conventional designs in which the primary winding is provided throughout by a conductor wire with complex insulation, in the present invention, a substantial proportion of the entire winding 130 is provided in the form of the guide bow 135. In some illustrative embodiments, at least a substantial part of the guide bar 135 is completely off Material of the partition wall 1 12c enclosed, so that the partition wall 1 12c serves as an efficient isolation path for insulating the winding 130 relative to the winding 120. It should be noted that the conductor bow 135 is to be understood as a coherent piece of a stable conductive material, which encloses the main body 1 at least over half the circumference or significantly more.

The remainder of the coil 130, in some embodiments, has a high insulation resistance due to the insulating material provided on the conductor 131 in the form of suitable insulation. In this way, the wound bobbin 100 can be wound in a manner suitable for automating, for example, first by applying the winding 120 and then inserting the conductor wire 131 into the respective recesses 13 of the partitions 121 a, 121 b and then using the conductor bow 135 is connected, for example by welding, soldering, and the like, such as via a terminal pin, as explained in more detail below, and wherein a further pin (not shown) is provided to connect the other end of the second winding 130. The conductor bow 135 can thereby be introduced before winding or can also be introduced after the application of the winding 120 in the partition 1 12c, which has a recess with a suitable cross-sectional shape, so that the conductor bracket 135 can be inserted.

For this purpose, the conductor bow 135 has any suitable cross-sectional shape, for example square, rectangular, oval, etc., and the respective opening in the partition wall 121 c has a cross section designed to be suitable, so that the conductor bow can be inserted and positioned accordingly in the partition wall 121 c , In other embodiments, the conductor bar is inserted into the partition wall 1 12c such that the conductor bar on the outside of the coil body 100 is not shielded from material of the coil body. In this case, a similar embedding of the conductor bow 135 results, as shown for the conductor 131 in the partitions 1 12a, 1 12b. As a rule, a subsequent casting of the bobbin 100 takes place, even later a higher insulating strength and mechanical stability can be achieved by the potting material, even if the conductor bracket 135 is not completely enclosed by material of the partition 1 12c.

In further embodiments, the connecting wire 131 can also be used as a non-insulated wire, since due to the design-related distances of the Final wire 131 of the winding 120 sufficient insulation distances are given, which result after casting. That is, by the precise guidance of the conductor bow and the conductor 131 through the recesses in the partitions exactly set insulation distances can be obtained after casting. In this way, very inexpensive materials can be used as connecting wire 131.

In further embodiments, the conductor 131 is provided in the form of one or more further conductor brackets, so that approximately in one or more of the partitions 1 12a, 1 12b, a corresponding conductor bracket is used and thus has similar properties, as previously shown for the conductor bracket 135 ,

FIG. 1 b schematically shows a plan view of the conductor bar 135 according to an illustrative embodiment. In this embodiment, the conductor bar 135 has the terminal pin 135a appropriately designed in length and cross-sectional shape, thereby enabling contact with a circuit board and the like. Furthermore, a body 135d is shown, which essentially represents the region of the conductor bow 135 which is received by the associated partition wall of the bobbin. As shown, in this embodiment, the body 135d has a larger dimension in a width direction B than the pin 135a. Furthermore, a connecting pin 135b is shown, which serves for contacting the conductor of the second winding and is designed so that on the one hand an efficient connection with the second winding, for example by soldering, welding, pressing and the like is made possible, and on the other hand an influence on the connecting pin 135a is avoided when installing in a circuit board. In the illustrated embodiment, this is accomplished by taking the length, i. In Fig. 1b, the vertical extension of the connecting pin 135b is smaller than the length, i. the vertical extent of the terminal pin 135a. Further, in the embodiment shown, a connecting pin 135c is provided which serves as a tap of the second winding, for example to make a connection to the first winding, if this is necessary for the relevant circuit arrangement. In other embodiments, the connecting pin 135c is not provided.

As already explained above, the conductor bow 135 is to be understood as a coherent piece of conductor material which is dimensionally stable and designed in such a way that it encloses a substantial portion of the basic body. FIG. 1 c schematically shows a plan view of the wound bobbin 100, the connection side being shown here. The connecting pin 135a of the conductor bow, which is guided in the partition wall 12c, thus constitutes one end of the winding 130, while the connecting pin 135b serves as a connection for the conductor 131, which is then led to the next partition wall 12b in order to carry therein second turn of the winding 130 to provide. The third turn of the winding 130 is thus formed in the partition wall 12a, which is then led to a further connecting pin 136a, which thus makes contact with the other end of the winding 130. In the illustrated embodiment, the terminal pin 136a is provided in the same partition wall 12c, in which the conductor bracket and thus the terminal pin 135a are also included. In other embodiments, the terminal pin 136a may also be provided in another bulkhead, if a different terminal configuration is desired. For example, the connection pin 136a may be provided in the form of a conductor bow in the partition wall 12a, so that overall a significantly shorter length for the conductor 131 is sufficient.

Fig. 1 d shows a variant again in plan view from below, ie with a view towards the terminal pins 135a, 136a and the connecting pin 135b. With this embodiment, an improved coupling of the windings 130 and 120 (see Fig. 1 a) can be achieved. For this purpose, the width 132b of the guide bow 135 is increased, while the connecting pin 135a and the connecting pin 135b have a significantly smaller cross-section, as is suitable for contacting a printed circuit board. That is to say, the corresponding part of the guide bow 135, ie the body 135d (see Fig. 1b), extends into the "depth" of the secondary winding (not shown) and thus provides for improved coupling, that is to say the pins in the embodiment shown 135a, 136a are designed so that they are compatible with corresponding holes in an assembly, so have other lateral dimensions compared to the conductor bow 135 having the greater width, ie the larger lateral dimension along the width direction B of the bobbin 100. Auch For example, in the illustrated embodiment, the terminal pin 135b is provided with a smaller width so as to obtain well-defined dimensions and conditions when contacting the insulated conductor 131 (see Fig. 1a), that is, in this embodiment, the terminal pins 135a , 136a as well as the connection pin 135b provided with small dimension, so that desired small Abme 132b, while the remainder of the conductor strap 135 has a greater width, as indicated by 132b, for improved electrical and magnetic efficiency. Beispiels- For example, the terminal pins 135a, 136a of any suitable cross section and having a width of 1 mm or less may be provided, while the remaining portion of the conductor bracket 135 has a width of 2 to 3 or more mm. In particular, this results in a greater width compared to the diameter of the connecting wire 131 (see Fig. 1 a), if this is provided as a round wire. In the case of using further conductor brackets, as described above, larger widths can be achieved in other turns of the primary winding, so that the coupling can be further improved.

FIG. 1 e schematically shows a side view of a transformer 150, in which the wound bobbin 100 is integrated. In other words, in the transformer 150, the conductor bow 135 with the connection pin 135a forms part of the primary winding, which thus runs essentially within the partition walls, resulting in a high level of mechanical and electrical interference immunity. The secondary winding 120 is divided into the winding chambers suitable, as also shown above, so that for desired high output voltages of 20,000 volts and significantly higher, a very compact design is guaranteed with low material requirements. In the illustrated embodiment, the wound bobbin 100 is embedded in a potting material 151 and is electrically and also mechanically connected to the terminal pin 135a and to the terminal pin 136a (see Fig. 1d), not shown, to a printed circuit board or substrate 152. Further, a suitable rod core 153 is provided in the transformer 150, which is constructed of any suitable magnetic material so as to achieve the desired output voltage. The core 153 is designed as a rod core, in contrast to ring-shaped arrangements, so that a compact structure results, at the same time an automatic winding winding at least the winding 120 is ensured. It should be noted, however, that the "rod core" 153 may also be provided in the form of a non-rectilinear core, such as a bow core or angled rectilinear core portions, with the wound bobbin 100 correspondingly geometrically adapted to this design 1c, a high-voltage connection for the winding 120 is not shown and can be provided in any desired manner another terminal pin may be provided in one of the partitions of the bobbin 100, or any other connection scheme may be provided. In the embodiment shown, the transformer 150 may be suitably designed so that in the case of a Length of about 4 cm or less, ie a length of 4 cm or less of the wound bobbin 100, an output voltage of 20,000 volts or more can be provided, wherein in a steady state operation after providing the high ignition voltage, a voltage of a few 100 volts can be performed over the transformer 150, so as to operate a discharge lamp. In this case, the transformer 150 is designed to handle powers of a few 10 watts to 100 watts or more. In order to further improve the magnetic properties of the transformer, additional magnetic elements in the form of end plates or other field-guiding plates and the like may also be provided.

Claims

protection claims

1 . Winding bobbin (100) for a transformer (150) having a plurality of winding chambers (1 1 1), which are on a base body (1 10) separated by partitions (1 12 a, 1 12 b, 1 12 c), a first winding (120), in the plurality of winding chambers (1 1 1) on the base body (1 10) is applied, a second winding (130) with one or more turns of a conductor (131), wherein the conductor (131) at least one of the one or more turns at least partially in recesses (1 13), which are formed in the partitions (1 12a, 1 12b, 1 12c) is guided, and a provided with a pin (135 a) conductor bracket (135) in one of the partitions (1 12a , 1 12b, 1 12c) and forms part of a turn of the second winding (130).

The wound bobbin of claim 1, wherein the conductor bar has a terminal post (135b) connected to conductors (131) of the second winding (130).

The wound bobbin according to claim 2, wherein a second terminal pin (136a) is provided in one of the partition walls (1 12c) and connected to one end of the second coil (130).

The wound bobbin according to claim 3, wherein the terminal pin (135a) and the second terminal pin (136a) are provided in the same partition (1 12c).

The wound bobbin of any one of claims 1 to 3, wherein the conductor bracket (135) has a connection pin (135c) for coupling one end of the first winding (120).

The wound bobbin according to any one of claims 1 to 5, wherein a width (132b) of at least a part of the conductor bar along a width direction (B) of the bobbin is larger than a dimension of the conductor in the longitudinal direction of the transformer.

The wound bobbin of any one of claims 1 to 6, wherein the second winding has less than 5 turns.

The wound bobbin according to any one of claims 1 to 7, wherein a length of the bobbin is 4 cm or less.

9. Winding bobbin according to one of claims 1 to 8, wherein the bobbin is designed for application to a straight or non-linear rod core.

10. Winding bobbin according to one of claims 1 to 9, wherein the conductor bar is inserted into the partition wall.

1 1. A transformer with a wound bobbin (100) according to any one of claims 1 to 10, and a longitudinal core (153) enclosed by the bobbin.

12. Transformer according to claim 1 1, further comprising an insulation of potting compound (151) which encloses at least the bobbin (100) with the first (120) and the second winding (130).

13. The transformer of claim 1 1 or 12, wherein the first winding is designed for operation with a voltage of 20,000 volts and higher.