ELECTRICAL ARRANGEMENT WITH THROTTLE COIL

Description

State of the art

[0001] The present invention relates to an electrical arrangement comprising a choke coil and a circuit substrate. In particular, the present invention relates to an electrical arrangement for controlling traction motors of electrically driven means of transport.

[0002] Toroidal core chokes are used in the filter units of electric vehicles to electrically attenuate interference frequencies. The closed design is the preferred electrical design. However, the use of a closed choke in the filter unit assembly requires the current conductor to be threaded through the choke and then electrically reconnected. A double feedthrough of the current conductor proves to be highly advantageous from an electrical perspective, since the number of turns contributes quadratically to the attenuation. The current flow in the choke passage is very difficult to cool and thus leads to heating of the choke core.

[0003] US2009 / 146768A1 describes an electrical product having an electrical circuit comprising a magnetic device and a fastening component therefor.

[0004] There is a need for a damping concept with double current feedthrough and simple installation. Disclosure of the invention

[0005] The present invention relates to an electrical arrangement comprising a circuit substrate and a choke coil with conductors. The choke coil is arranged on the circuit substrate such that the stripped terminals of its conductors are received in a respective terminal clamp, wherein the stripped terminals are each held in one of the plurality of terminal clamps. In other words, terminal clamps are fastened to the circuit substrate (e.g., glued, riveted, soldered, or similar), which have a particularly elastic holder for the stripped terminals of the choke coil conductors. In this case, the terminal clamps can be elastically bent open upon insertion of the stripped terminals and undercut after a predefined path through the terminal clamps. In other words, the stripped conductor end snaps or engages in the terminal clamp and is secured against unwanted removal from the terminal clamp.A suitable geometric design of the terminal clamps can ensure a large contact area with the respective stripped conductor connection. In particular, the surfaces of the stripped connections can correspond with the terminal clamps in sections to ensure flat contact of the terminal clamps with the stripped connections. In particular, the stripped connections can have a substantially cylindrical conductor shape (e.g., like a copper wire), while the terminal clamps have opposing jaws with cylindrically concave surfaces. When assembled, the surface of the terminal clamp thus forms a jacket section surface for the stripped connections.In this way, assembly is simplified compared to arrangements known in the prior art and the positioning of the stripped connections in the connection clamps is (at least initially) reversible, so that a correction of stripped connections initially located in an incorrect connection clamp is easily possible.

[0006] The subclaims show preferred developments of the invention.

[0007] Preferably, the plurality of terminal clips can be electrically connected to a respective conductive track on the circuit substrate. In other words, the terminal clips are electrically connected to a respective conductive track on the circuit substrate in order to electrically connect the choke coil to the surrounding peripherals. The terminal clips can be soldered, welded, riveted, conductively bonded, or similarly bonded to the conductive tracks.

[0008] Preferably, the stripped terminals can also be welded into the terminal clamps. In other words, after the stripped terminals have been inserted, the terminal clamp can be contacted from the outside by one or two electrodes such that, when an electrical voltage is applied, the welding current generated by the terminal clamps and the stripped terminals creates a bonded connection between the terminals and the terminal clamps. In particular, the terminal clamps can also be welded to the circuit substrate (e.g., to the respective conductor track) in this process. This protects the choke coil against mechanical and electrical decoupling from the circuit substrate.

[0009] For example, the retaining clips and the choke coil can be arranged entirely on one side of the circuit substrate. In this configuration, all components of the choke coil (core assembly, electrical conductors, etc.) are arranged on the same side of the circuit substrate as the connection clips. However, at least one center of gravity of the choke coil is located on the same side of the circuit substrate as the connection clips. Alternatively, the choke coil or its center of gravity can be located on a side of the circuit substrate opposite the clips, and only the electrical conductors and stripped connections that are partially routed to the opposite side of the circuit substrate are located on the side of the connection clips, with the stripped connections being arranged in the connection clips. With this configuration, the design can be kept flat compared to a respective surface of the circuit substrate.

[0010] The terminal clamps can, for example, have a base with a flat surface (mounting surface) for a flat and stable connection to the circuit substrate. Alternatively or additionally, retaining lugs can be provided on both sides of the base that curve over the base to accommodate the stripped connections. In this case, the terminal clamp can be manufactured (bent) from a single sheet metal part. Due to the retaining lugs curving over the flat base, a spring deflection can be ensured for setting a suitable, predefined preload of the retaining lugs. In this way, the stripped connections can be held particularly securely, and contacting the retaining lugs with welding electrodes can be carried out conveniently and reliably next to the stripped connections.

[0011] In particular, the retaining lugs can have a depth that is less than the depth of the base. In other words, the terminal clamp made from a sheet metal strip can, on the one hand, have a sufficiently large width / depth at the point where the base rests flat against the circuit substrate. A smaller width / depth of the retaining lugs that curve over the base can ensure that the preload on the stripped terminals is not too great, allowing them to be inserted into the terminal clamps reliably and without risk to the surrounding components.

[0012] The retaining lugs can have distal ends that are oriented perpendicular to the surface of the circuit substrate upon insertion of the stripped terminals and that first come into contact with the stripped terminals during assembly of the choke coil. These distal ends can have a contact surface with the stripped terminals that is substantially perpendicular to the surface of the circuit substrate. Two opposing distal ends clamp the stripped terminals of the choke coil conductors between them. For this purpose, they can have a gap that tapers towards the surface of the circuit substrate to facilitate threading of the stripped terminals and simultaneously ensure sufficiently large pretension in an end position of the stripped terminals.For this purpose, the distal ends can be spaced apart at an increased distance from each other in the area of ​​the end position of the stripped terminals, so that when removed in a direction perpendicular to the surface of the circuit substrate, the stripped terminals necessarily initially push the distal ends apart again until, after being (completely) removed by the stripped terminals, they spring back toward each other slightly. The distal ends are thus oriented more perpendicular to the surface of the circuit substrate than an adjacent area of ​​the retaining lugs.

[0013] The choke coil can have a core assembly with an eye (bore) through which the conductors are guided. For example, three or four conductors can be guided through the eye and returned on an outer side of the core assembly. Positioning aids / positioning structures can be provided in the eye and / or on an end face of the core assembly and / or on a lateral surface of the core assembly in order to simplify accurate and predefined positioning of the conductors during assembly of the choke coil. The positioning structures can comprise webs and / or grooves, for example. They can run radially on the end face and / or coaxially to the eye on the lateral surface. This is particularly true if the core assembly has an elastic surface (e.g. made of a suitable plastic, or similar).is manufactured), the conductors can be fitted, in particular pressed, into the grooves and prevented by a holding force of the positioning structures against accidental loosening or (partial) bending back towards an initial shape of the conductor.

[0014] The core assembly can further preferably have positioning aids that promote / facilitate positioning of the choke coil on the circuit substrate. In particular, predefined structures of the core assembly can engage in corresponding recesses in the circuit substrate, thus enabling rotationally secure positioning of the choke coil relative to the circuit substrate.

[0015] In particular, a rotational position around a longitudinal axis can be coded through the eye of the choke coil during assembly, allowing only a single rotational position of the choke coil relative to the circuit substrate. This effectively prevents electrically incorrect assignment of the conductors to the terminal clamps.

[0016] Further preferably, the choke coil or the core assembly can have a mechanical stop that interacts with a corresponding structure (e.g., an edge / flange around a recess) in the circuit substrate. In other words, the choke coil can only be inserted into the recess through the circuit substrate to a certain predefined depth until the stop rests against a surface of the circuit substrate (in particular, flatly). This flange surface can be glued to the circuit substrate. The flange prevents vibrations of the choke coil relative to the circuit substrate or tilting of the choke coil relative to the circuit substrate. In particular, it can be ensured that the overall height of the choke coil has particularly small tolerances relative to the surface of the circuit substrate.

[0017] The stripped terminals of the choke coil can each be led away from the coil in a radial direction in a star shape. In other words, the stripped terminals gather in a common plane that lies parallel to a surface of the circuit substrate. In this way, the plurality of connection clamps can also have an identical design and / or an identical height above the surface of the circuit substrate. The design of the electrical arrangement is thus further reduced. In this case, the stripped terminals or the connection clamps can in particular be arranged equidistant from one another. In other words, adjacent connection clamps can each have an identical angle to one another. In particular, the stripped terminals can have an angle of 45° to one another.

[0018] The electrical arrangement disclosed here can be prefabricated using simple conductor sections. The dimensions of the parts must be adapted to their current-carrying capacity and attenuation properties. Subsequent installation can be carried out position-oriented and on a standard carrier (circuit substrate, printed circuit board, pre-molded stamped part, or similar), avoiding threaded assembly with intermediate connection processes. During final assembly, the choke coil can be inserted into a can structure provided for cooling and shielding. This places this component in its own EMC zone, which has a beneficial effect on attenuation. Short description of the drawings

[0019] Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Figure 1 is a perspective view of a choke coil for use in an electrical arrangement according to the invention; Figure 2 is a perspective view of a choke coil according to Figure 1 from below; Figure 3 in Figure 2 illustrated arrangement after aligning the conductors guided through the eye of the coil core in the radial direction; Figure 4 a circuit substrate and a sectional view through a choke coil according to Figure 3 in conjunction with a circuit substrate for mounting the choke coil on both sides; and Figure 5 is a perspective view of the Figure 4 shown components and arrangement of the stripped conductor ends in additionally shown connection clamps. Embodiments of the invention

[0020] Figure 1shows a choke coil 4 with four electrical conductors 5, which have stripped terminals 6 on both sides. The conductors 5 are inserted into positioning structures 9 arranged on the end face of the core assembly 8. The positioning structures 9 are designed as pairs of parallel webs on both sides of the radially extending sections of the conductors 5. Furthermore, two positioning aids 10 are arranged on the core assembly 8, which engage in recesses (not shown) in a circuit board (not shown) and prevent the choke coil 4 from being secured against rotation relative to the circuit board.

[0021] Figure 2 shows the Figure 1 The choke coil 4 shown in an upside-down view. Positioning structures 9 in the form of webs are also provided on the opposite end face for the ends of the conductors 5, which are still aligned coaxially in the illustrated arrangement.

[0022] Figure 3shows the Figure 2 The choke coil 4 shown here, after the conductors 5 projecting from the eye 14 of the core assembly 8 have been bent into the grooves provided by the webs 9 and thus have reached a radial alignment. The stripped conductor ends 6 now all lie in a plane that runs normal to an axis through the eye 14 of the core assembly 8.

[0023] Figure 4 shows a perspective view of a circuit substrate 2, which has two protruding positioning aids 10 ( Figure 2) has corresponding recesses 11. The choke coil shown in a sectional view, which also has a stop 16, can therefore only be arranged in one direction of rotation. In addition, the recess 12 has bays for the sections of the conductors 5 running on the outside of the core assembly 8. This secures the conductors 5 in the circuit substrate 2 after the choke coil 4 has been inserted into the recess 12. The joining geometry (the entirety of the recesses 11, 12 and the bays 15) in the circuit substrate 2 thus determines the position and orientation of the choke coil 4 in its end position. In the end position, the stop 16 can be glued to the surface of the circuit substrate 2. Alternatively, a locking lug can also be arranged on the core assembly 8, which enables a (provisional or final) fixing of the choke coil 4 in the circuit substrate 2.

[0024] Figure 5 shows the Figure 4illustrated components after assembly, wherein the stripped terminals 6 are held in terminal clips 3. The terminal clips 3 have a respective base 32 with a first (greater) depth T, to which respective retaining lugs 36 are connected at opposite ends. The retaining lugs 36 have distal ends 35 which are substantially perpendicular to a surface of the circuit substrate 2. The retaining lugs 36 have a depth t which is smaller than the depth T of the base 32. The retaining lugs 36 initially curve over the respective base 32, while their distal ends 35 are bent upward in the opposite direction in order to clamp the stripped terminals 6. Three terminal clips 3 are connected to exemplary conductor tracks 7 on the circuit substrate 2.The electrical contact resistance between the stripped terminals 6 and the terminal clamps 3 can be further reduced by placing welding electrodes on the retaining lugs 36 (and / or applying them to the distal ends 35) and a welding current bonding the components together.

Claims

1. Electrical arrangement (1) comprising - a circuit substrate (2) with a plurality of connection clips (3), and - a choke coil (4) with conductors (5), which have stripped connections (6), wherein the stripped connections (6) are each held in one of the plurality of connection clips (3).

2. Electrical arrangement according to Claim 1, wherein the plurality of connection clips (3) are electrically connected to a respective conductor track (7) on the circuit substrate (2).

3. Electrical arrangement according to Claim 1 or 2, wherein the stripped connections (6) are welded in the connection clips (3).

4. Electrical arrangement according to any of the preceding claims, wherein - the connection clips (3) and the choke coil (4) are all arranged on one side of the circuit substrate (2), or - the connection clips (3) and a centre of gravity of a core assembly (8) of the choke coil (4) are arranged on different sides of the circuit substrate (2).

5. Electrical arrangement according to any of the preceding claims, wherein the connection clips (3) have: - a flat base (32) resting on the circuit substrate (2) and / or - retaining lugs (36) bending over the base (32) on opposite sides of the base (32).

6. Electrical arrangement according to Claim 5, wherein the retaining lugs (36) - have a depth (t), which is less than a depth (T) of the base (32), and / or - have distal ends (35), which are oriented substantially perpendicularly to the base (32).

7. Electrical arrangement according to any of the preceding claims, wherein the choke coil (4) has a core assembly with an eye (14) through which the conductors (5) are guided, wherein the core assembly (8) has positioning structures (9) in particular on an end surface and / or on a lateral surface, the conductors (5) being inserted, in particular pressed, into the positioning structures.

8. Electrical arrangement according to Claim 7, wherein the core assembly (8) has protruding positioning aids (10), which engage into corresponding recesses (11) in the circuit substrate (2).

9. Electrical arrangement according to any of the preceding claims, wherein the choke coil (4) is guided through a recess (12) in the circuit substrate (2) on a side opposite the connection clips (3) with respect to the circuit substrate (2) and the core assembly (8) has a stop (15), which rests on a surface of the circuit substrate (2) on the side on which the connection clips (3) are located.

10. Electrical arrangement according to any of the preceding claims, wherein the stripped connections (6) are guided out in a star-shaped manner in the radial direction in a common plane.