The present invention relates to an inductive component and to a method of manufacturing an inductive component and, in particular, to the compliance with insulation requirements for very compact inductive components.
Inductive components, such as transformers and chokes, are used in a plurality of fields of application. One field of application are electronic systems in automobiles, where inductive components are used, inter alia, as ignition transformers for gas discharge lamps or filter chokes, by way of example. The extensive developments in automotive electronics that have been promoted in the automotive industry led to a significant increase in the number of electronic components, e.g. for use in vehicles as instrument clusters, which are used for displaying data in automotive vehicles, for controlling the engine control with control of the ignition system or the injection system, in anti-lock braking systems and vehicle dynamics control systems, in the control of airbags, in body control units, in driver assistance systems, in car alarm systems and multimedia devices, e.g. navigation systems, TV tuners, etc.
The increasing number of electronic devices in automobiles as a result of this development necessitates e.g. further adjustments of the electronic components as regards their size, so as not to exceed the installation spaces given in the automotive vehicle through the vehicle design in question, in spite of the increasingly extensive and complex electronic systems used in automotive vehicles. In general, there are further demands on the electronic system in automotive vehicles as regards robustness, temperature range (e.g. a guarantee of operability in a temperature range from −40° C. to about 120° C.), resistance to vibrations and shocks (caused by shaking during vehicle operation), etc., whereby the reliability of the electronic system should be guaranteed with respect to a great variety of conditions and states over the longest possible period of time.
In addition to the application-related conditions concerning a component size, which aims in particular at a more compact structural design of electronic components so as to comply with given installation spaces, e.g. a given mounting area, which is the maximum mounting area that an electronic component is allowed to occupy on a carrier, such as a printed circuit board, to which the electronic component is to be attached, generally specified safety standards must be observed by all means, without, in turn, impairing the performance and the quality of electronic components. For example, safety standards for realizing uniform minimum safety standards specify insulation requirements to be met by electronic components, such as the compliance with specified air and leakage paths and the compliance with a specified dielectric strength.
In general, an air path is here defined as the shortest distance between two conductive parts, especially the shortest possible connection via air, across recesses and gaps and transversely through insulating attachments, which are not connected in full area and without any gaps to the underground. The air path depends, inter alia, on the voltages applied, electronic components being assigned to predefined overvoltage categories. The overvoltages that have to be taken into account in this respect are those entering the electronic component from outside via connections (e.g. connecting terminals of an electronic component) as well as those generated in the electronic component itself and occurring at the connections. Predefined air paths are intended to prevent a voltage breakdown from occurring over possible shortest connections through air. In this sense, air paths limit maximum possible electric fields in air, so that no breakdown will occur.
The leakage path, however, is the shortest possible connection between two potentials via a surface of an insulating material arranged between the two potentials. The leakage path generally depends on the effective operating voltage of an electronic component and is influenced e.g. by the degree of contamination and/or the degree of moistening of a surface of an insulating material. For example, a tracking resistance of an insulating material is determined by the insulation resistance of a surface of the insulating material under the influence of moisture and/or contamination, and may be understood as defining the maximum leakage current that is allowed to occur in a defined test arrangement under standardized test conditions. The tracking resistance depends essentially on the water absorption capacity and the behaviour of an insulating material under thermal stress.
In addition, the insulation distance is understood as the strength of an insulating material, so that this value is important for determining the dielectric strength of an insulating material.
From safety standards that make demands on air paths, leakage paths and insulation distances, constraints result, depending on the dimensions of an electronic component, for a sufficient insulation so as to avoid voltage breakdowns (e.g. electric arcs or sparking) and/or leakage currents as a potential safety risk. For example, voltage breakdowns in the form of electric arcs or sparking will have to be avoided in the context of explosion protection, while leakage currents are a safety risk for a user who comes into contact with a leakage current source.
Taking into account the above explanations, it is the object of the present invention to provide inductive components having a compact structural design for mounting in small installation spaces while observing predefined safety standards, in particular without providing air paths and/or leakage paths and/or insulation distances that are shorter than the predefined paths/distances.
According to one aspect, the present invention provides an inductive component, comprising a magnetic core, an insulation body formed of an electrically insulating material and having the magnetic core accommodated therein, and a coil body having the at least one winding wound thereon. The insulation body comprises at least two insulation wall sections, which are connected to each other and which each face, at least partially, a respective side surface section of the magnetic core. The coil body comprises at least one contact element attached to a side surface section of the coil body and used for establishing an electric connection to the at least one winding, and a magnetic core accommodation in which the magnetic core accommodated in the insulation body is partially accommodated. A side surface section of the magnetic core, which faces the at least one contact element, is covered, at least partially, by an insulation wall section of the insulation body.
In view of the fact that the insulation body provided comprises at least two mechanically connected insulation wall sections, one of these insulation wall sections of the insulation body covering, at least partially, the magnetic-core side surface section facing the contact elements in the inductive component, sufficiently long air and leakage paths are guaranteed in a safe and reliable manner, independently of the dimensions of the inductive component.
According to an advantageous embodiment of this aspect, the side surface section of the magnetic core, which faces the contact elements, is fully covered by the insulation wall section. Leakage currents can be suppressed very efficiently in this way.
According to a further advantageous embodiment of this aspect, the insulation body and the coil body are mechanically connected by connection devices. In this way, the insulation body and the coil body can be provided separately, whereby a modularization of the inductive component and a retrofittable adaptation of air and leakage paths will be possible.
According to a more advantageous further development of this embodiment, the connection devices may comprise at least one first connection element arranged on the insulation body and at least one second connection element arranged on the coil body, the connection elements entering into mechanical engagement with each other. Through this kind of mechanical connection of the insulation body and the coil body, also reliable mounting of the insulation body and the coil body can easily be accomplished.
According to another more advantageous further development of this embodiment, the connection devices may be configured for coupling the insulation body and the coil body in a mechanically releasable manner. Leakage path extensions in the inductive component can thus be accomplished easily. Exchange and retrofitting of individual components will here be possible in case of need.
According to a further advantageous embodiment of this aspect, the insulation body is defined by at least three insulation wall sections, which are mechanically connected to one another such that the insulation body has a pot-like or cup-like shape including a recess in which the magnetic core is accommodated. An insulation body having this kind of structural design can easily be manufactured by injection molding techniques and can be produced in large quantities at a reasonable price. In addition, a pot-like or cup-like shape of the insulation body allows the core to be accommodated in the insulation body in a mechanically stable manner.
According to an advantageous further development of this embodiment, a depth of the recess may be larger than or equal to a height dimension of the magnetic core, the height dimension being defined with respect to the magnetic core along a direction along which the magnetic core is accommodated in the recess. This additionally allows to specify, according to a depth of the recess, an air and leakage path length along the entire height dimension of the magnetic core. As a result, very compact inductive components can be provided.
According to a further advantageous embodiment of this aspect, the insulation body further comprises at least one web section, which is formed on the insulation wall section and which faces the at least one contact element and projects outwards away from the insulation body along a normal direction of the insulation wall section. By means of the outwards projecting web sections, a mechanical stability of the insulation body is accomplished on the one hand, and, on the other hand, the web sections allow the air and leakage paths to be laterally enlarged.
According to an advantageous further development of this embodiment, the at least one web section may comprise a projecting portion projecting towards the coil body and inserted in a respective positioning opening formed in the coil body and arranged on a side on which at least one contact is arranged. In this way, a mechanically reproducible positioning of the insulation body on the coil body can be accomplished, which allows e.g. an advantage as regards a mechanical fitting of insulation bodies to coil bodies. Furthermore, exact positioning of the magnetic core on the coil body and thus relative to the winding provided above the coil body can be accomplished in this way.
According to another advantageous further development of this embodiment, at least two contact elements may be provided on a side surface section of the coil body, and two wire sections of the at least one winding may extend along the at least one web section on opposite sides of the latter to a respective one of the contact elements. Hence, a mechanical separation of the wire sections can be accomplished by means of the web section, so that the air and leakage paths between the two wire sections will be extended by means of the web section.
According to another advantageous embodiment of this first aspect, the inductive component further comprises at least one further contact element attached to a side surface section of the coil body, the side surface section being arranged on a coil body side located opposite the at least one contact element, a further magnetic core, and a further insulation body, the further insulation body comprising at least two insulation wall sections, which are connected to each other and which each face, at least partially, a respective side surface section of the further magnetic core, wherein the further insulation body is arranged on the coil body such that it is located opposite the insulation body, and the further magnetic core, which is accommodated in the further insulation body, is partially accommodated in the magnetic core accommodation, and wherein a side surface section of the further magnetic core, which faces the at least one further contact element, is covered, at least partially, by an insulation wall section of the further insulation body. In this way, an advantageous core design, composed of two individual magnetic cores, can be provided independently of dimensions of the inductive component, while satisfying predefined insulation distances. According to an advantageous further development of this embodiment, each of the two magnetic cores have an E-core configuration.
According to a further aspect of the present invention, a method of manufacturing an inductive component according to the above aspect is provided. The method comprises the steps of winding at least one winding onto the coil body and incorporating the magnetic core in the insulation body. The method further comprises the step of attaching the insulation body with the magnetic core accommodated therein to the wound coil body, the magnetic core being partially incorporated in the magnetic core accommodation of the coil body.
In the following, further advantages and features of the present invention will be described in more detail in connection with the figures enclosed, in which:
Making reference to
As shown in
The shape of the bottom-side insulation wall section 22 may be adapted to the magnetic core 10. For example, the bottom-side insulation wall section 22 may have provided therein openings, which are surrounded by the U-shaped insulation wall sections 27 (in the representation according to
The insulation wall sections 24, 26 project from the bottom-side insulation wall section 22 along a normal direction of the bottom-side insulation wall section 22, so that the reception unit 25 is defined by the bottom-side insulation wall section 22 and the insulation wall sections 24, 26 projecting therefrom. The insulation body 20 is open with respect to a side opposed to the bottom-side insulation wall section 22 and a side of the bottom-side insulation wall section 22 opposed to the insulation wall section 24.
This does not represent a limitation of the present invention, and a side of the insulation body 20 located opposite the bottom-side insulation wall section 22 may partially be covered by an insulation wall section (not shown) provided there. For example, an insulation wall section (not shown) having an area that is smaller than the base area of the bottom-side insulation wall section 22, e.g. an area that is at most half the size of this base area, opposite the bottom-side insulation wall section 22, may cover the U-shaped insulation wall section 24. This optional insulation wall section (not shown) may be provided as a “pick and place cap” which may be engageable by e.g. for a suction port on a conveying device (not shown) in an automated production process.
The bottom-side insulation wall section 22 is mechanically connected to the insulation wall sections 26 and the insulation wall section 24, the insulation wall section 24 being arranged on an edge of the bottom-side insulation wall section 22 and extending away therefrom in the normal direction with respect to the bottom-side insulation wall section, so that the insulation wall section 22 extends transversely to the direction of extension of the insulation wall sections 26 and is mechanically connected to the insulation wall sections 26.
According to the representation in
Although the insulation wall sections 24, 26 are shown in the representation according to
The insulation body 20 further comprises two web sections 28, which are formed on the insulation wall section 24. The two web sections 28 shown do not represent a limitation of the present invention, and an arbitrary number of web sections 28 may be formed along the insulation wall section 24, e.g. only one web section (cf.
The web sections 28 have a projecting portion 28a which extends in the normal direction of the insulation wall section 24 and thus projects in the normal direction to the insulation wall section 24 from the latter. The web sections 28 may additionally comprise a projecting portion 28b, which extends along the normal direction of the bottom-side insulation wall section 22 and which projects downwards from the insulation body 20 along an underside of the bottom-side insulation wall section 22.
With respect to
As can be seen from
According to the above described height dimensions of the magnetic core 10 and the above described depth of the reception unit 25, it is ensured that a side surface 14 of the transverse yoke Sd of the magnetic core 10, which, in the magnetic core condition shown in
Making still reference to
Making reference to
The coil body 30 shown in
According to the representation shown in
According to the representation in
Furthermore, a wall section 34b is formed opposite the connection section 36c, the wall section 34b connecting the winding chamber sections 34a and 34c with each other. Thus, the magnetic core accommodation 32 is enclosed by the winding chamber sections 34a, 34c, the connecting sections 36c and the wall section 34b located opposite to the latter.
In accordance with some illustrative embodiments, as shown explicitly in
Making reference to
Additionally or alternatively, the contact strip 36b may have formed therein at least one opening 38b (e.g. two, as illustratively shown in
According to some illustrative embodiments, the openings 38a and 38b in the respective contact strips 36a and 36b may be formed between respective neighbouring contact elements, e.g. the contact pins 50a and 50b, (alternatively at least one opening may also be formed in only one contact strip). For example, the contact elements, e.g. the contact pins 50a and 50b in the respective strip 36a and 36b, may also be subdivided into subgroups of contact elements by the respective openings 38a and 38b, the degree of subdivision depending on the respective case of use. The number of openings formed in one of the contact strips 36a, 36b may be different from or equal to the number of openings formed in the other of the contact strips 36a, 36b. In any case, the number of openings is related to the number of projecting portions 28b formed on the insulation body 20 (cf.
In an illustrative example of the first embodiment, a height HS of a projecting portion 28b is smaller than or equal to the thickness (cf. d in
According to a concrete illustrative structural design of the first embodiment, the height HS of at least one projecting portion 28b is greater than a thickness (cf. d in
Making reference to
According to illustrative embodiments, the insulation body 20a is arranged on the coil body 30 such that the insulation body 20a is located opposite the insulation body 20 and the magnetic core 10a accommodated in the insulation body 20a is partially accommodated in the magnetic core reception unit 32 of the coil body 30. A side surface section 14a of the magnetic core 10a, which faces the at least one further contact element 50a, is at least partially covered by the insulation wall portion 24a of the insulation body 20a.
From an alternative point of view, the inductive component 100 may be regarded as having a modular magnetic core 10′. This modular magnetic core 10′ may be formed according to a double-E-core configuration from the E-shaped magnetic cores 10, 10a, as shown. This does not represent a limitation and, instead of two E-cores, also two C-cores, one E-core and one C-core, one E-core and one I-core, and one C-core and one I-core may be combined in the inductive component 100.
From the point of view of a modular magnetic core 10′, the individual magnetic cores 10, 10a represent individual core segments of the modular magnetic core 10′.
According to the representation shown in
According to the representation in
Although only one web section 28 is shown in
Although the modular or integral insulation body 20′ in the representation of
Making reference to
Referring still to
It follows that the respective air and leakage paths required between the contact pins 50a, 50b of the inductive component 100 and the magnetic cores 10, 10a are determined through the height of the insulation bodies 20, 20a. Advantageously, the leakage path extension takes place independently of a base area of the inductive component 100, in particular a bottom-side area of the coil body 30. This means, in turn, that the inductive component 100 can be provided in a very compact manner while observing the necessary air and leakage paths.
The inductive component 100 according to the first embodiment can be manufactured according to the following method steps. The magnetic cores 10 and 10a (or the magnetic core segments of the modular magnetic core 10′) are incorporated into the respective insulation bodies 20, 20a. Optionally, each of the magnetic cores 10, 10a may adhesively be secured in position in the respective insulation body 20, 20a, or may be mounted in the respective insulation bodies 20 and 20a in some other way, e.g. through structures according to locking projections or locking hooks (not shown), which are provided on the insulation body 20, 20a in question, or by attaching a top insulation cover to the respective insulation bodies 20, 20a after incorporation of the magnetic cores 10, 10a. In this way, the respective individual magnetic cores 10, 10a are incorporated into the individual insulation bodies 20, 20a and can be provided separately at this time.
Independently of the provision of the magnetic cores 10, 10a in the insulation bodies 20, 20a, the coil body 30 has wound thereon at least one winding W1, e.g. in an automatic winding process.
Subsequently, each of the insulation bodies 20, 20a including the respective magnetic cores 10, 10a are attached to a respective one of the contact strips 36a, 36b in the way described above. To this end, middle legs (cf. Sc in
Optionally, the individual magnetic cores 10, 10a may be fixed to each other by adhesive bonding on end faces of the magnetic cores 10, 10a, which are in contact with one another, the magnetic core 10′ being provided as a unit. Additionally or alternatively, the individual insulation bodies 20, 20a may be attached to the coil body 30 by means of adhesive bonding and the like.
The inductive component 100 shown in
In summary, first embodiments of the inductive component 100 are described with respect to
The side surface section 14 of the magnetic core 10, which faces the at least one contact element 50b, may here be fully covered by the insulation wall section 24.
Furthermore, the insulation body 20 and the coil body 30 may be mechanically connected by the connection devices 28, 38. The connection devices 28, 38 may here comprise at least one first connection element 28 arranged on the insulation body 20 and at least one second connection element 38 arranged on the coil body 30, which enter into mechanical engagement with one another. Additionally or alternatively, the connection devices 28, 38 may be configured for coupling the insulation body 20 and the coil body 30 in a mechanically releasable manner.
In addition, the insulation body 20 may be formed by at least the three insulation wall sections 22, 24, 26, which are connected to one another such that the insulation body 20 has a pot-like or cup-like shape including the recess 25 in which the magnetic core 10 is accommodated. A depth of the recess 25 may here be larger than or equal to the height dimension H10 of the magnetic core 10, the height dimension being defined with respect to the magnetic core 10 along a direction along which the magnetic core 10 is accommodated in the recess 25.
Furthermore, the insulation body 20 may also comprise at least one of the web sections 28, which is formed on the insulation wall section 24 and which faces the at least one contact element 50b and projects outwards away from the insulation body 20 along a normal direction of the insulation wall section 24. This at least one web section 28 may comprise the projecting portion 28b projecting towards the coil body 30 and inserted in the respective positioning opening 38 formed in the coil body 30 and arranged on the coil body side on which the at least one contact element 50b is arranged. In addition, the contact elements 50b may be provided in a number of two contact pins on the side surface section 37b of the coil body 30 and at least the two wire end sections Wa and Wb of the at least one winding W1 may extend along the at least one web section 28 on opposite sides of the latter to a respective one of the contact elements 50b.
Furthermore, the inductive component 100 may at least additionally comprise one of the contact elements 50a, which is arranged on the side surface section 37a of the coil body 30 disposed on the coil body side located opposite the contact element 50b, the further magnetic core 10a and the further insulation body 20a, the further insulation body 20a comprising at least the insulation wall section 24a, which faces the side surface section 14a of the further magnetic core 10a at least partially, and a further insulation wall section, which is connected thereto and which faces, at least partially, a further side surface section (a side surface section connected to the side surface section 14a) of the further magnetic core 10a, the further insulation body 20a being arranged on the coil body 30 such that it is located opposite the insulation body 20 and the further magnetic core 10a, which is accommodated in the further insulation body 20, is partially accommodated in the magnetic core accommodation 32. The side surface section 14a of the further magnetic core 10a, which faces the at least one further contact element 50a, may be covered, at least partially, by the insulation wall section 24a of the further insulation body 20a, and the magnetic cores 10, 10a may each have an E-core configuration.
Making reference to
Apart from this, the structural design of the coil body 230 corresponds to that of the coil body 30 and comprises in particular contact strips 236a, 236b, which are connected by a connection area (not shown) corresponding to the connection section 360. Furthermore, contact pins 250a, 250b are formed in the respective end faces 237a, 237b of the respective contact strips 236a, 236b.
The insulation body 220 comprises a bottom-side insulation wall section 222 and insulation wall sections 224 and 226 extending away from the bottom-side insulation wall section 222 along a normal direction of the latter. Furthermore, the bottom-side insulation wall section 222 has formed therein U-shaped insulation wall sections 227 corresponding to the U-shaped insulation wall sections 27 in the representation according to
The insulation body 220 has formed therein a recess 225, which is laterally surrounded by the insulation wall sections 224 and 226. A depth of the recess 225 is defined by an insulation wall section height H220, as has been stated in a corresponding manner in connection with
The recess 225 in
According to some illustrative embodiments, the magnetic core 210 may be a magnetic core 210 of a modular type, which is composed of individual magnetic cores 210a, 210b. The magnetic cores 210a, 210b may by fixed to each other by adhesive bonding, so as to provide the magnetic core 210 in an integral form when the inductive component 200 has been provided.
The insulation body 220 can be used in the event that, in the inductive component 200, only one contact strip 236a has provided thereon contact elements 250a, which are provided for applying a high voltage thereto (high voltage terminals are to be provided on one contact strip), whereas the other contact strip 236b has provided thereon contact elements 250b, which are intended to have applied thereto a low voltage potential. Accordingly, an advantageous air and leakage path extension to the magnetic core 210 and the winding W2 over the coil body 230 is provided by means of the insulation body 220 on the high voltage carrying side of the inductive component 200, in particular on the contact strip 236a of the high-voltage contact elements 250a, through the insulation wall section 224 facing the high-voltage terminals.
The mounting of the insulation body 220 on the coil body 230 according to the representation in
The inductive component 200 shown in
In summary,
In addition, the side surface section 214 of the magnetic core 210, which faces the at least one contact element 250a, may here be fully covered by the insulation wall section 224.
Furthermore, the insulation body 220 and the coil body 230 may be mechanically connected by the connection devices 240. The connection devices 240 may here comprise at least the first connection element 242 arranged on the insulation body 220 and at least the second connection element 244 arranged on the coil body 230, which enter into mechanical engagement with one another. The connection devices 240 may be configured for coupling the insulation body 220 and the coil body 230 in a mechanically releasable manner.
In addition, the insulation body 220 may be formed by at least three insulation wall sections, which are connected to one another, so that the insulation body 220 has a pot-like or cup-like shape including the recess 225 in which the magnetic core 210 is accommodated.
Furthermore, the depth of the recess 225 may here be larger than or equal to the height dimension H210 of the magnetic core 210, the height dimension being defined with respect to the magnetic core 210 along the direction along which the magnetic core 210 is accommodated in the recess 225.
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