EP3128522A2 - Coil body - Google Patents

Abstract

In one aspect of the invention, there is provided a bobbin (100) having a hollow housing body (110) having on a first side (A) an opening (112) for receiving a coil into the housing body (110) along an insertion direction (C) and a housing wall (114) extending between the first side (A) of the housing body (110) and an opposite second side (B), a plurality of electrical contacts (120) and a plurality of along the housing wall (114) extending guide grooves ( 130), each adapted to guide a lead wire to connect a coil received by the housing body (110) to the contacts (120), and the guide grooves (130) projecting from the housing wall (114) and along the insertion direction ( C) are formed parallel ribs (132), wherein the contacts (120) on the second side (B) on the housing body (110) are mounted, wherein the bobbin (100) further on Ra (113) has slots (117) formed in the opening (112), which are arranged on the opening (112) in the circumferential direction, so that for each guide groove (130) a passage in the housing body (110) into or out of the housing body (110), and wherein each two ribs (132) form a guide groove (130) and the ribs (132) of each one guide groove (130) are all spaced from the ribs (132) of the other guide grooves (130) an isolation groove (134) is formed between two guide grooves (130).

Description

The present invention relates to a bobbin for inductive components, such as e.g. Transformers and chokes.

Inductive components, such as chokes and transformers, are used in many technical fields, for example in the automotive industry. There are used in automotive electronics circuit board components, such as in power electronics, in which so-called pulse transformers or pulse transformers are used to control the gate of an electronic switching element. A "gate-drive transformer" is a pulse transformer that controls the timing of power MOSFETs or IGBTs in switch-mode-power-supply (SMPS), such as in the publication " A guide to designing gate drive transformers ", power electronics technology, 2007: 32-36, by Patrick Scoggins is shown.

Typically, gate-drive transformers include a bobbin-mounted coil that may be configured both as surface-mountable (SMD) devices or through-hole devices. In this case, as with general electrical and electronic components, safety standards must be adhered to, i.a. demand compliance with insulation and creepage distances. The requirements for creepage distances and insulation distances are normally met by potting the bobbins in a housing with a potting compound.

During the assembly of printed circuit boards with inductive components, reflow soldering processes are carried out, i.a. to electrically and mechanically connect inductive components to printed circuit boards. During the soldering processes, high temperatures occur, so that a component is frequently exposed to temperature fluctuations of 100 ° C. or more in the production process. Due to the differing coefficients of expansion between the different materials in inductive components, for example, between the potting compound, the bobbin, the ferrite core and the winding, consequently, different thermal expansions occur, which lead to stresses in the material and ultimately to breakage. For example, the potting compound often tears, as a result of which the creepage distances and clearances of an inductive component are greatly reduced and the standard requirement according to IEC / UL etc. can no longer be met.

During operation, a component may continue to be exposed to temperature fluctuations. For example, automotive electronics near the engine are also subject to high temperature fluctuations during operation exposed from -40 ° C to + 155 ° C or more. Furthermore, electrical and electronic components of automotive electronics are subject to high mechanical loads due to vibrations.

Based on the situation described above, a bobbin for an inductive component is to be provided, in which the disadvantages described above are eliminated.

The present invention provides a solution to the above problem in various aspects. It is proposed to replace the potting compound by appropriately designed design measures. This is inventively achieved in that the creepage distances are extended, so that can be dispensed with the potting compound.

In a first aspect of the invention, there is provided a bobbin having a hollow housing body having on a first side an opening for receiving a coil in the housing body along an insertion direction and a housing wall extending between a first side of the housing body and an opposite second side extends. The housing body further includes a plurality of electrical contacts and a plurality of guide grooves extending along the housing wall, each configured to guide a lead wire to connect a coil received by the coil bobbin to the contacts disposed on the second side of the housing. The bobbin also has slits formed on the edge of the opening, which are arranged on the opening in the circumferential direction, so that a defined passage is provided into the housing body or out of the housing body for each guide groove. These are especially tuned to the extension of creepage distances in the area of the opening. The guide grooves are formed by protruding from the housing wall and along the insertion direction parallel ribs. In this case, each two ribs form a guide groove and the ribs each have a guide groove are all spaced from the ribs of another guide groove, so that in each case an insulating groove is formed between two guide grooves.

It is achieved an advantageous extension of creepage distances and Isolierstrecken in the bobbin, since between two guide grooves an isolation groove is formed.

In another illustrative embodiment of the first aspect, at least one guide groove extends completely along the housing wall.

In a further illustrative embodiment of the first aspect, the housing body is configured to receive a toroidal coil.

As described above, the guide grooves are formed by ribs which protrude from the housing wall and run parallel along the insertion direction. In this way, guide grooves for efficient creepage extension are easily provided.

As described above, each two ribs form a guide groove and the ribs of each one guide groove are all spaced from the ribs of the other guide grooves, so that an isolation groove is formed between each two guide grooves. This provides a further advantageous extension of creepage distances between the lead wires routed in the guide grooves.

In a further advantageous embodiment herein, the isolation grooves have different depths. In some examples herein, the withstand voltage is further increased that the isolation grooves are provided with greater depth respectively between the guide grooves into which the lead wires are inserted, which are at a greater potential. Thus, a more compact design of the bobbin can be achieved.

In a second aspect of the invention, a bobbin is provided with two contact strips formed on opposite sides of the bobbin, each having a plurality of electrical contacts. Each contact strip in this case has guide grooves formed in a surface of the contact strip, each of which is designed to guide a connecting wire to connect a coil attached to the bobbin with at least one of the contacts of the corresponding contact strip, it being advantageous that the guide grooves of a first Contact strip of the two contact strips are longer than the guide grooves of the other second contact strip. In this case, each guide groove in the surface of at least the first contact strip is formed by two ribs protruding from the surface. Furthermore, an isolation groove is formed in at least one rib.

In one illustrative embodiment of the second aspect, the contacts on the first contact strip are located at a greater distance from a receiving area for a coil than the contacts on the second contact strip.

In a more advantageous embodiment herein, at least the guide grooves of the first contact strip with increasing distance from the receiving area on a constant or increasing depth.

As described above, each guide groove in the surface of at least the first contact strip is formed by two ribs protruding from the surface. In some illustrative Examples herein, a height and / or a width of each rib is greater than or equal to a depth and / or width of each guide groove.

In a further illustrative embodiment of the second aspect, an isolation groove is formed between two guide grooves of at least the first contact strip.

In another illustrative embodiment of the second aspect, the guide grooves of at least the first contact strip are spaced from each other by ribs formed in the surface.

In another illustrative embodiment of the second aspect, the guide grooves fully penetrate the surface of the first contact strip along a direction parallel to the surface.

In another illustrative embodiment of the second aspect, ends of the contacts for connection to terminals of the coil on the first contact strip terminate in a contact plane from the first contact strip, and the contact plane is offset parallel to the surface by an offset.

Fig. 1a bis 1 c

einen Spulenkörper gemäß einem ersten Aspekt der Erfindung in unterschiedlichen Ansichten schematisch darstellen; und

Fig. 2a bis 2c

einen Spulenkörper gemäß einem zweiten Aspekt der Erfindung in unterschiedlichen Ansichten schematisch darstellen.

Further advantages and features of the present invention will become apparent from the following description together with the accompanying figures, in which the

Fig. 1a to 1 c

schematically illustrate a bobbin according to a first aspect of the invention in different views; and

Fig. 2a to 2c

schematically illustrate a bobbin according to a second aspect of the invention in different views.

Fig. 1a schematically shows a perspective view of a bobbin having a hollow housing body 110. The housing body 110 is preferably designed to receive a toroidal coil (coil is not shown). The coil may comprise a magnetic core (not shown) and at least one winding (not shown). Alternatively, the coil may be provided without a magnetic core.

As shown Fig. 1a the housing body 110 has an opening 112 on a first side A of the housing body 110, so that a coil (not shown) along an in Fig. 1a direction indicated by the reference character "C" can be inserted into the housing body 110. Preferably, the housing body 110 is closed on one of the first side A opposite second side B. That is, in the housing body, a bottom 115 is provided, which serves as a support surface for a recorded in the housing body coil (not shown). Between the first side A and the second side B, a housing wall 114 extends, so that a coil accommodated in the housing body 110 is surrounded by the bottom 115 and the housing wall 114.

In the housing wall 114 between the first side A and the second side B parallel to the direction C extending guide grooves 130 are formed. The guide grooves 130 preferably extend completely along the housing wall between the first side A and the second side B of the housing body 110. Each of the guide grooves 130 is preferably configured to fully receive a lead wire, ie, a depth of each guide groove 130 is greater than or equal to one Diameter of the connecting wire (not shown).

As in Fig. 1a 2, a plurality of contacts 120 are attached to the second side B. The plurality of contacts is used for electrical and mechanical attachment of the bobbin 100 to a circuit board (not shown). For this purpose, at least one contact 120 to an electrical and / or mechanical connection between the printed circuit board (not shown) and bobbin 100 may be provided. According to one embodiment, the contacts 120 may be L-shaped and project downwardly from the housing body 110 along the direction C. An exposed end of the at least one contact 120 is therefore preferably bent along a direction perpendicular to the direction C. In this way, an SMD component is provided. Alternatively, the exposed ends of the contacts 120 extend substantially along a direction parallel to the direction C, so that the contacts 120 are formed as a through-contact.

Regarding Fig. 1b is a plan view of the housing body 110 (along the direction C in Fig. 1a ). The contacts 120 are shown in phantom in the illustrated plan. As from the presentation in the Fig. 1 a and 1 b, each guide groove 130 is formed by two mutually spaced ribs 132 which extend along the direction C on the housing wall 114 and perpendicular to the direction C of the housing wall 114, in particular normal to the mantle surface of the housing wall 114 protrude.

In some illustrative embodiments, an isolation groove 134 is formed between each two adjacent guide grooves 130. The isolation grooves 134 and the guide grooves 132 are accordingly arranged alternately along the housing wall 114 (seen in the circumferential direction). As seen from the supervision in Fig. 1b As can be seen, a depth of each isolation groove 134 may vary along the circumferential direction about the opening 112. For example, outer isolation grooves 134a may have a greater depth than inner isolation grooves 134, eg, the central isolation groove 134m in Fig. 1 b. Are now laid in the outer guide grooves connecting wires to which a greater potential difference is applied, a comparatively greater isolation distance is provided by means of the insulating grooves formed between these guide grooves with comparatively greater depth than is the case, for example, with more central guide grooves. According to an illustrative example herein, a depth of the isolation groove 134 may depend on an azimuthal position of the isolation groove 134 along a circumferential direction of the opening 112, as in FIG Fig. 1b is shown.

In an exemplary embodiment, the at least one isolation groove may be provided as a recess in a rib, wherein the isolation groove may be incorporated in a rib during manufacture of the coil body, for example during manufacture or subsequently, e.g. by removing or eliminating material of the rib. In a specific example, a depth of the at least one isolation groove may be equal to or deeper than a depth of at least one guide groove.

It will open Fig. 1a and Fig. 1c Referenced. It shows Fig. 1c a planar side view of the bobbin 100 from Fig. 1 As shown, a passageway may be provided between a guide groove 134 and the interior of the housing body 110 by means of a slot 117 formed at the edge 113 of the opening 112. In some illustrative examples herein, each of the slots 117 is formed at the edge 113 of the opening 112 with a depth that is substantially greater than a diameter of a lead wire 122, which in the illustration of FIG Fig. 1c is connected to at least one winding of a coil received in the housing body 114. As a result, when the lead wire is guided from inside the housing body 110 to the outside of the housing body 110, an advantageous withstand voltage is provided.

According to some embodiments, not shown, the in Fig. 1 a bobbin 100 shown, if the bobbin is not alone on the contacts 120 on a circuit board (not shown) to install, further fastening means for fastening and / or orientation means for orientation of the bobbin 100 on a circuit board include, such as snap hooks, clips, positioning pins, etc ., Which protrude from an underside of the bobbin 100 along the direction C. Further, a lid (not shown) may be provided to cover the opening 112 of the housing body 110.

With reference to the Fig. 2a and 2 B Alternative embodiments of the present invention will be described. Fig. 2a shows a bobbin 200, which is preferably formed for an inductive component with a double E or EI core configuration. The bobbin 200 has a first contact strip 210, a core guide region 220 and a second contact strip 230. The first contact strip 210, the core guide region 220 and the second contact strip 230 may be at least partially integral or modular, ie the first contact strip 210 and / or the core guide region 220 and / or the second contact strip 230 may be attached to each other (optionally detachably) or integrally as be formed an element.

In some illustrative embodiments, the core guide region 220 is configured to receive at least one leg of an E and / or I core. For this purpose, the core guide region 230 has a core holding region 232, for example the illustrated holder or snap hooks (not shown), etc.

As shown in Fig. 2a For example, contacts 240 are disposed on the first contact strip 210 and on the second contact strip 230. As shown, the contacts 240 may be formed as L-shaped contact pins, the exposed ends 244, 242 of which protrude from the contact strips 210, 230. Alternatively, the contacts 240 may be formed as U-shaped contact pins, thereby providing an SMD component.

An attachment of a magnetic core to the bobbin 200 can be effected, for example, by guiding the core (not shown) through guide surfaces 212 on the first contact strip 210 and 232 on the second contact strip 230 along an insertion direction D into the bobbin 200 and holding naps 224 in one Receiving portion 226 of the bobbin 200 is held in cooperation with the support structure 222. Connecting wires for windings (not shown), in Fig. 2a on the underside of the bobbin 200, guided to the exposed ends 244 of the contacts 240 and connected thereto. Via the exposed ends 242 of the contacts 240, the coil body 200 is connected to a printed circuit board (not shown) (electrically and / or mechanically).

Fig. 2b FIG. 12 illustrates a bottom view of the bobbin 200. In a bottom side surface 210U of the in Fig. 2a illustrated contact strip 210 guide grooves 214 are formed. Likewise, guide grooves 234 are formed in a surface 230U of the second contact strip 230 on the underside. The guide grooves 214 and 234 serve to receive and guide a lead wire (not shown) of a winding (not shown) to be mounted over the bobbin 200. In this case, a connecting wire (not shown) is guided by a guide groove 214 to the free end 244 of a contact 240 and thus, for example by winding around the free end 244 and fixation at the free end 244, electrically connected. The guide grooves 214 are separated from each other in the surface 210U of the contact strip 210 formed ribs 216 separated from each other. Accordingly, the guide grooves 234 are defined in the lower surface of the second contact strip 230 by ribs 236.

In some illustrative embodiments, an isolation groove 218 is formed in at least one rib 216. The isolation groove 218 thus contributes to the extension of the creepage distance between two adjacent guide grooves 214 in addition to the rib 216. According to illustrative examples, a depth of the at least one isolation groove 218 is less than or equal to a depth of at least one of the surrounding guide grooves 214. In addition, an isolation groove may be provided at least in at least one of the ribs 236 of the second contact strip 230.

In some illustrative embodiments of the present invention, a height and / or a width of each rib is greater than or equal to a depth and / or width of each guide groove.

In an exemplary embodiment, the at least one isolation groove may be provided as a recess in a rib 236, wherein the isolation groove may be incorporated in a rib during manufacture of the coil body, for example during manufacture or subsequently, e.g. by removing or eliminating material of the rib. In a specific example, a depth of the at least one isolation groove may be equal to or deeper than a depth of at least one guide groove 214.

A further improvement in the withstand voltage of the bobbin 200 can be achieved, for example, in that the guide grooves 214 of the first contact strip are longer than the guide grooves 234 of the second contact strip 230. According to some illustrative embodiments, this is achieved in that the contacts 240 on the first Contact strip 210 are arranged at a greater distance from the receiving area 226, as the contacts 240 on the second contact strip 230. For example, the contacts 240 may be provided on the first contact strip 210 as a high-voltage contacts in the use of the bobbin 200.

It will open Fig. 2a Referenced. The exposed ends 244 of the contacts 240 are disposed in a plane K, at least on the first contact strip 210, according to some illustrative embodiments. The plane K is offset by an offset V from the underside surface 210U of the first contact strip 210. Thus, an isolation distance between the leads and the exposed ends of adjacent contacts can be advantageously set.

Fig. 2c shows a plan view of the bobbin 200 from Fig. 2a , to which a magnetic core M and a winding 250 are attached. The winding 250 is arranged, for example, over the support structure 222, which may serve as a winding chamber, for example. Exposed ends 252 of the coil 250 may be electrically connected to exposed ends 244 of the contacts 240.

In some illustrative examples, the magnetic core M may be realized by three I-cores or an EII core configuration. Alternatively, the core is formed according to a double-E configuration (see dashed lines) or an EI core configuration.

A distance d1 between the core M and the winding 250 from the contacts 240 on the first contact strip 210 is greater than a distance d2 between the contacts 240 on the second contact strip 230 and the core M or the winding 250. This represents an extended Creepage distance at the first contact strip 210 ready. According to a specific example: d1 ≥ 1.5 * d2 or d1 ≥ 2 * d2 or d1 ≥ 3 * d2.

Claims (12)

A bobbin (100) having a hollow housing body (110) having on a first side (A) an opening (112) for receiving a coil in the housing body (110) along an insertion direction (C) and a housing wall (114) extending between the first side (A) of the housing body (110) and an opposite second side (B), a plurality of electrical contacts (120) and a plurality of along the housing wall (114) extending guide grooves (130), each for guiding a Connection wire are formed to connect a through the housing body (110) recorded coil with the contacts (120), and the guide grooves (130) by of the housing wall (114) projecting and along the insertion direction (C) parallel ribs (132) wherein the contacts (120) on the second side (B) on the housing body (110) are mounted, wherein the bobbin (100) further on the edge (113) of the opening (112) formed slots (117) a Provided on the opening (112) in the circumferential direction, so that for each guide groove (130) a passage in the housing body (110) in and out of the housing body (110) out is provided, and wherein each two ribs (132 ) form a guide groove (130) and the ribs (132) are each a guide groove (130) all of the ribs (132) of the other guide grooves (130) spaced so that between two guide grooves (130) each formed an isolation groove (134) is. The bobbin (100) of claim 1, wherein at least one guide groove extends completely (130) along the housing wall (114). The bobbin (100) of claim 1 or 2, wherein the housing body (110) is configured to receive a toroidal coil. The bobbin (100) according to any one of claims 1 to 3, wherein the isolation grooves (134) have different depths. The bobbin (100) according to any one of claims 1 to 4, wherein a depth of at least one guide groove (130) is equal to or less than a depth of the at least one isolation groove (134). Bobbin (200) having two contact strips (210, 230) formed on opposite sides of the bobbin (200), each having a plurality of electrical contacts (240), each contact strip (210; 230) being formed in a surface (210U; 230U ) the guide rail (210; 230) formed guide grooves (214; 234), each adapted to guide a lead wire to a coil on the body (200) mounted coil with at least one of the contacts (240) of the corresponding contact strip (210; 230), wherein the guide grooves (214) of a first contact strip (210) of the two contact strips (210; 230) are all longer than the guide grooves (234) of the other second contact strip (230), wherein each guide groove (214) in the surface (210U) of at least the first contact strip (210) is formed by two ribs (216) projecting from the surface (210U), and wherein at least one rib (216) further comprises an isolate nsnut (218) is formed. The bobbin (200) according to claim 6, wherein the contacts (240) on the first contact strip (210) are arranged at a greater distance from a receiving region (226) for a magnetic core than the contacts (240) on the second contact strip (230). , Spool (200) according to claim 7, wherein at least the guide grooves (214) of the first contact strip (210) with increasing distance from the receiving area (226) have a constant or increasing depth. The bobbin (200) of any one of claims 6 to 8, wherein a height and / or a width of each rib (216) is greater than or equal to a depth and / or width of each guide groove (214). The bobbin (200) according to any one of claims 6 to 9, wherein a depth of at least one guide groove (214) is equal to or less than a depth of the at least one isolation groove (218). The bobbin (200) according to any one of claims 6 to 10, wherein the guide grooves (214) fully penetrate the surface (210U) of the first contact strip (210) along a direction parallel to the surface (210U). The bobbin (200) of any one of claims 6 to 11, wherein ends (244) of the contacts (240) for connection to terminals of the coil on the first contact strip (210) in a contact plane (K) of the first contact strip (210) protrude and the contact plane (K) parallel to the surface (210U) offset by an offset (V) is arranged.

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