Choke, and method for manufacturing such a choke

Abstract

The invention relates to a choke (1) comprising: at least one winding (2) each having two connections (3, 4); and a magnetic core (5) provided with an air gap (6), wherein a coil body (8) consisting of at least two parts (9, 10) is provided for receiving the at least one winding (2), and a base plate (11) that can be connected to the coil body (8) is also provided. According to the invention, the at least two parts (9, 10) of the coil body (8) and the base plate (11) have first latching elements (12, 14) and second latching elements (13, 15) for connecting, without tools, the at least two parts (9, 10) of the coil body (8) and for connecting, without tools, the base plate (11) to the coil body (8), and the magnetic core (5) is constructed from a plurality of sheets (7) stacked one on top of the other, and the base plate (11) is designed to receive the sheets (7) of the magnetic core (5).

Description

[0001] Throttle and method for producing such a throttle

[0002] The invention relates to a choke with at least one winding with two terminals each and a magnetic core provided with an air gap, wherein a coil body consisting of at least two parts is provided for receiving the at least one winding and furthermore a base plate connectable to the coil body.

[0003] Furthermore, the invention relates to a method for producing or assembling such a throttle.

[0004] A choke is a coil or inductor used to limit currents in electrical lines, temporarily store energy, match impedance, or filter. Such chokes with a magnetic core are used for various functions, particularly in high-performance electrical devices. The magnetic core has an air gap to prevent saturation.

[0005] Such chokes are used, for example, in inverters, especially photovoltaic inverters, in the power section, for example as output filter chokes. Such chokes are also used in welding machines, battery chargers, and other electrical devices.

[0006] WO 2018 / 33451 A1 describes a push-pull power choke in which at least two choke units are connected to each other via a magnetic shunt to reduce stray magnetic fields. A screw connection is required for assembling the chokes.

[0007] DE 20 2015 102 905 U1 protects a coil former for a transformer that contains locking elements on the front flange areas, to which additional coil formers can be mechanically coupled. The structure of the individual coil formers is not discussed in detail.

[0008] Chokes of the type in question are known, for example, from US 2003 / 0098769 A1, US 2014 / 0266527 A1, or DE 11 2012 002 017 T5. The construction and manufacture or assembly of the components is complex and also requires the use of adhesives, tools, or other aids.

[0009] Chokes whose magnetic core consists of a large number of stacked laminations, particularly of iron or another magnetic material, are usually manufactured and assembled by screwing the lamination stack together using screws and pressure plates. Additionally, a so-called air gap plate made of non-magnetic material is often included in the legs of the magnetic core to create a defined air gap. The labor required and thus the labor costs for assembling the laminations of the magnetic core are very high during the manufacture and assembly of the choke. Additional costs are incurred for the screws, pressure plates, and the air gap plate.

[0010] The object of the present invention is to create a choke and a method for producing such a choke, whereby a choke can be manufactured or constructed as quickly and easily as possible and, if possible, without additional parts. The disadvantages of known chokes, which must be manufactured with relatively great effort, are to be avoided or at least reduced.

[0011] The object of the invention is achieved by an above-mentioned choke, wherein the at least two parts of the coil former and the base plate have first locking elements and second locking elements for the tool-free connection of the at least two parts of the coil former and for the tool-free connection of the base plate to the coil former, and the magnetic core is constructed from a large number of laminated sheets stacked on top of one another, and the base plate is designed to receive the laminated sheets of the magnetic core. According to the invention, a coil former comprising at least two parts and a base body are created, which hold the at least one winding and the laminated sheets of the magnetic core and can be connected to one another without tools via the corresponding first and second locking elements. The laminated sheets of the magnetic core are held in the desired position by the parts of the coil former and the base plate, without the need for fastening screws or corresponding tools.At the same time, the parts of the coil former and the base plate are designed in such a way that the desired air gap in the magnetic core is maintained without the need for a separate air gap plate. By appropriately designing the locking elements, a simple and rapid tool-free connection of the at least two parts of the coil former can be achieved after the at least one winding of the choke has been accommodated. The base plate of the choke and the at least two parts of the coil former preferably also have locking elements for tool-free connection of the base plate to the coil former. In this way, the magnetic core consisting of the stacked sheets can be assembled in the correct position without the use of additional fastening elements such as fastening screws and can be held in this position after the base plate has been connected to the coil former.This means that the choke can be manufactured and assembled particularly quickly and easily. Depending on the design of the parts of the coil former and the base plate and the first and second locking elements, it may also be possible to separate the base plate from the coil former and the parts of the coil former, thus enabling the choke to be disassembled. Disassembly is preferably also carried out without the use of tools. The locking elements can also be designed in such a way that the parts of the coil former and the coil former can only be connected to the base body once. Assembled chokes are often immersed in a varnish or resin bath to insulate them and, above all, to protect the sheets of the magnetic core from corrosion. In this case, disassembly of the choke is neither intended nor desired.

[0012] The first locking elements can, for example, each be formed by a locking lug, and the second locking elements by an opening or a projection for receiving the locking lug. This represents a simple implementation of a tool-free connection.

[0013] Ideally, the coil former and the base plate are made of plastic, which has no influence on the magnetic field of the choke and provides electrical insulation between the magnetic core and at least one winding. This means that the components of the choke can be manufactured easily and cost-effectively. The corresponding locking elements for connecting the parts of the coil former and for connecting the base plate to the coil former are preferably provided during the manufacture of the parts of the coil former and the base plate, so that no complex subsequent machining of the components is necessary. When selecting the plastic, attention must be paid to ease of processing and certain properties, such as temperature resistance or flame retardancy. Polyamide, for example, is suitable for the manufacture of the coil former and the base plate.

[0014] The coil body and base plate are preferably manufactured using an injection molding or 3D printing process. This allows even more complex geometries of the choke components to be manufactured quickly and, at least for larger quantities, cost-effectively.

[0015] If the base plate contains pins and the sheets have corresponding openings for the construction of the magnetic core, the sheets can be stacked on top of each other on the pins to form the magnetic core easily and, above all, without the need for tools.

[0016] The pins of the base plate preferably have stiffening ribs. Such stiffening ribs provide the pins with the necessary stability, even with thin material thicknesses, and ensure the correct positioning of the magnetic core laminations by adapting the openings in the laminations to the cross-sectional contour of the pins.

[0017] The magnetic core can consist of an E-shaped part and an I-shaped part, with the air gap formed between the free ends of the E-shaped part and the I-shaped part. Depending on the design of the choke, windings can be arranged on one or all of the legs of the E-shaped magnetic core, which generate the corresponding magnetic field.

[0018] An edge for forming the air gap is arranged on at least part of the coil body. Such an edge on at least part of the coil body allows a defined air gap to be defined and maintained without the need for an air gap plate as a separate component of the choke. This further simplifies the manufacture of the choke and its assembly.

[0019] If openings are provided in the base plate for the connections of at least one winding, this results in quick and easy mounting of the choke on a printed circuit board or the like, with simple electrical contacting of the choke connections. The connections of the prefabricated windings protrude through these openings in the base plate and can be quickly and easily soldered to contact surfaces on a printed circuit board or connected via clamp connections.

[0020] According to a further feature of the invention, a portion of the coil former contains elements for attaching the at least one winding. This allows the at least one prefabricated winding to be quickly arranged on these elements, and the choke can be manufactured quickly and, above all, without tools. Preferably, additional centering elements are provided, which center the at least one winding accordingly and determine its desired position.

[0021] The object of the invention is also achieved by an above-mentioned method for producing a choke, which comprises the following steps: a) placing and centering the at least one winding on the first part of the coil former; b) connecting the first part of the coil former to the second part of the coil former without the use of tools; c) pushing and stacking the sheets of the magnetic core into the coil former; d) connecting the base plate to the coil former without the use of tools. The choke can therefore be manufactured quickly, easily and without the use of tools, without the need for additional fastening elements such as fastening screws, pressure plates or air gap plates. In addition to the lower manufacturing outlay, the material costs can also be reduced. For further advantages, reference is made to the above description of the choke.Advantageously, before the base plate is connected to the coil body without the use of tools, the base plate and the pins are moved through the openings in the metal sheets. This allows the magnetic core to be assembled and held in its desired position without the use of fastening screws.

[0022] Advantageously, the tool-free connection of the first part of the coil body to the second part of the coil body and the tool-free connection of the base plate to the coil body is carried out by snapping locking lugs into corresponding openings on the parts of the coil body and the base plate.

[0023] If the assembled choke is immersed in a paint bath, especially a water-based paint bath, and dried preferably at a higher temperature, especially 100°C to 150°C, the choke can be insulated and protected from environmental influences and corrosion. Solvent-based paints can be used for this purpose. In addition, the assembled choke can also be coated with resins or encapsulated.

[0024] The present invention will be explained in more detail with reference to the accompanying drawings, which show an embodiment of the invention to which it is not intended to be limited. In these drawings:

[0025] Fig. 1 is a perspective view of a choke constructed according to the invention with an E-shaped magnetic core; and

[0026] Fig. 2-8 different views of the throttle according to Fig. 1 in different stages of production.

[0027] Fig. 1 shows a perspective view of a choke 1 constructed according to the invention with an E-shaped magnetic core 5. The choke 1 shown contains three windings 2, each with two connections 3, 4. The magnetic core 5 is constructed from a large number of sheets 7 stacked one above the other, in particular made of iron or an iron alloy. The magnetic core 5 consists of an E-shaped part 5' and an I-shaped part 5'', with an air gap 6 with a defined width being arranged between the free ends of the legs of the E-shaped part 5' and the I-shaped part 5''. The three windings 2 are arranged on the legs of the E-shaped part 5'' of the magnetic core 5 and produce a corresponding magnetic field when current flows through the windings 2. Furthermore, a coil body 8, preferably made of plastic, is provided to accommodate the windings 2.To ensure the arrangement of the windings 2 and subsequently their hold, the coil former 8 is constructed from at least two parts 9, 10 which can be connected to one another. Furthermore, a base plate 11 is provided, which is also preferably made of plastic and serves to hold the laminations 7 of the magnetic core 5. The base plate 11 can be connected to the coil former 8 or at least one part 9, 10 of the coil former. For tool-free connection of the at least two parts 9, 10 of the coil former 8 and for tool-free connection of the coil former 8 to the base plate 11, first locking elements 12, 14 and second locking elements 13, 15 are arranged on the parts 9, 10 of the coil former 8 and the base plate 11 (see Figures 2 to 8).

[0028] The base plate 11 preferably contains pins 16 on which the sheets 7 can be stacked one above the other to construct the magnetic core 5 with corresponding openings 17.

[0029] The pins may have stiffening ribs 24 (see Fig. 7). Openings 19 may also be arranged in the base plate 11 for the passage of the terminals 3, 4 of the windings 2.

[0030] The throttle 1 shown can be assembled or manufactured very easily and quickly without tools, without the need for fastening screws, pressure plates or air gap plates.

[0031] The manufacturing process of the throttle according to Fig. 1 is described in more detail with reference to Figures 2 to 8.

[0032] Fig. 2 shows a part 9 of the coil former 8 which serves to accommodate the windings 2. The part 9 of the coil former is preferably made of plastic using an injection molding process or 3D printing process. In addition to the elements 20 for receiving the windings 2, first locking elements 12 and second locking elements 15 are arranged for connection to the second part 10 of the coil former 8 and for connection to the base plate 11 (see Figures 4 and 8). The first locking elements 12 for connection to the second part 10 of the coil former 8 are formed by corresponding locking lugs 22. The second locking element 15 for connecting the part 9 of the coil former 8 to the base plate 11 is formed by an opening 23. Furthermore, centering elements 21 are provided on part 9 of the coil body 8, by means of which the windings 2 are centered and held in the desired position.

[0033] Fig. 3 shows part 9 of the coil former 8 with the arranged windings 2. The three windings 2 are pushed onto the elements 20 of part 9 and held in the desired position by the centering elements 21 (see Fig. 2). The terminals 3, 4 of the windings 2 protrude downward and can later be soldered, for example, to a printed circuit board (not shown).

[0034] According to Fig. 4, the second part 10 of the coil former 8 is connected to the part 9 without tools. For this purpose, second locking elements 13 are provided on the part 10, which are designed to be complementary to the first locking elements 12 of the first part 9 of the coil former 8. In the exemplary embodiment shown, the second locking elements 13 on the part 10 of the coil former 8 are designed for connection to the part 9 by openings 23 or projections, into which the first locking elements 12 of the part 9, designed as locking lugs 22, snap into place. To connect the coil former 8 to the base plate 11, corresponding second locking elements 15 are also arranged on the part 10, for example in the form of an opening 23 or a projection for receiving a locking lug 22 on the base plate 11.

[0035] During the manufacturing stage of the choke 1 according to Fig. 5, the sheets 7 are arranged to form the E-shaped part 5' of the magnetic core 5. To form an air gap to the I-shaped part 5'' of the magnetic core 5, the part 10 of the coil body 8 has an edge 18.

[0036] If, according to Fig. 6, the sheets 7 for forming the I-shaped part 5'' of the magnetic core 5 are arranged on the part 10 of the coil body 8, the edge 18 on the part 10 ensures that an air gap 6 with a defined width is maintained between the E-shaped part 5' and the I-shaped part 5'' of the magnetic core 5.

[0037] Fig. 7 shows a base plate 11 of the choke according to the invention, which is also preferably made of plastic by injection molding or 3D printing. The base plate 11 has pins 16, which preferably have stiffening ribs 24. Additionally, openings 19 are arranged in the base plate for the passage of the terminals 3, 4 of the windings 2. The stiffening ribs 24 of the pins 16 are designed such that the laminations 7 for forming the magnetic core 5 can be arranged with corresponding openings 17.

[0038] Fig. 8 shows how the base plate 11 is connected to the parts 9, 10 of the coil former 8 without the use of tools. For better visibility, the windings 2 and laminations 7 of the magnetic core 5 have been hidden. The connection of the base plate 11 to the parts 9, 10 of the coil former is achieved via the first locking elements 14 and the second locking elements 15, which are formed, for example, by locking lugs 22 and openings 23. The arrangement of the windings 2 and laminations 7 of the magnetic core 5 results in the choke 1 shown in Fig. 1.

[0039] The present invention enables a rapid and tool-free production of a choke 1 with at least one winding 2 and a magnetic core 5 interrupted by an air gap 6, without additional elements.

Claims

Patent claims:

1. Choke (1) with at least one winding (2) having two terminals (3, 4) and a magnetic core (5) provided with an air gap (6), wherein a coil former (8) consisting of at least two parts (9, 10) for receiving the at least one winding (2) and a base plate (11) connectable to the coil former (8) are provided, characterized in that the at least two parts (9, 10) of the coil former (8) and the base plate (11) have first locking elements (12, 14) and second locking elements (13, 15) for tool-free connection of the at least two parts (9, 10) of the coil former (8) and for tool-free connection of the base plate (11) to the coil former (8), and that the magnetic core (5) is constructed from a plurality of stacked laminations (7), and the base plate (11) for receiving the laminations (7) of the magnetic core (5) is trained.

2. Throttle (1) according to claim 1, characterized in that the first locking elements (12, 14) are each formed by a locking lug (22) and the second locking elements (13, 15) are formed by an opening or a projection (23) for receiving the locking lug (22).

3. Choke (1) according to claim 1 or 2, characterized in that the coil body (8) and the base plate (11) are made of plastic.

4. Choke (1) according to claim 3, characterized in that the coil body (8) and the base plate (11) are manufactured using an injection molding process or a 3D printing process.

5. Choke (1) according to one of claims 1 to 4, characterized in that the base plate (11) contains pins (16), and the sheets (7) for constructing the magnetic core (5) have corresponding openings (17) so that the sheets (7) can be stacked on top of each other on the pins (16), wherein the pins (16) preferably have stiffening ribs (24).

6. Choke (1) according to one of claims 1 to 5, characterized in that the magnetic core (5) consists of an E-shaped part (5') and an I-shaped part (5'' ) wherein the air gap (6) is formed between the free ends of the E-shaped part (5' ) and the I-shaped part (5'' ).

7. Choke (1) according to claim 6, characterized in that an edge (18) for forming the air gap (6) is arranged on at least one part (9, 10) of the coil body (8).

8. Choke (1) according to one of claims 1 to 7, characterized in that openings (19) for the passage of the connections (3, 4) of the at least one winding (2) are arranged in the base plate (11).

9. Choke (1) according to one of claims 1 to 8, characterized in that a part (9) of the coil body (8) contains elements (20) for mounting the at least one winding (2), wherein preferably additional centering elements (21) are provided for centering the at least one winding (2).

10. Method for manufacturing a choke (1) according to any one of claims 1 to 9, characterized by the following steps: a) placing and centering the at least one winding (2) on the first part (9) of the coil former (8); b) joining the first part (9) of the coil former (8) to the second part (10) of the coil former (8) without tools; c) inserting and stacking the laminations (7) of the magnetic core (5) into the coil former (8); d) joining the base plate (11) to the coil former (8) without tools.

11. Method for manufacturing a throttle (1) according to claim 10, characterized in that, prior to the tool-free connection of the base plate (11) with the coil body (8), the base plate (11) is moved through the openings (17) in the sheets (7) with the pins (16).

12. Method according to claim 10 or 11, characterized in that the tool-free joining of the first part (9) of the coil former (8) with the second part (10) of the coil former (8) and the tool-free joining of the base plate (11) with the coil former body (8) is done by snapping locking tabs (22) into corresponding openings (23) on the parts (9, 10) of the coil body (8) and the base plate (11).

13. Method according to one of claims 10 to 12, characterized in that the assembled throttle (1) is immersed in a lacquer bath, in particular a bath of water-based lacquer, and preferably dried at a higher temperature, in particular 100°C to 150°C.

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