Current limiting fuse

Abstract

A current limiting fuse (20) comprises an electrically insulating housing (2) having a wall surrounding an interior space (6), having a first opening (7) and having a second opening (8) opposite the first opening, and a monolithically formed electric conductor element (1) extending from a first terminal area (3) outside the housing, through the first opening, through the interior space, through the second opening, to a second terminal area (4) outside the housing, wherein the conductor element comprises a melting portion (5) having a reduced cross section, which melting portion is located in the interior space and is configured to melt when a predetermined maximum permissible current in the conductor element is exceeded, and wherein a first sealing portion (9) of the conductor element seals the first opening (7), and wherein a second sealing portion (10) of the conductor element seals the second opening (9). The invention also relates to a method of manufacturing a current limiting fuse.

Description

[0001] This invention relates to a current-limiting fuse and a method for manufacturing a current-limiting fuse.

[0002] Current-limiting fuses are protective devices used in a wide range of electrical engineering fields. A fuse is configured, for example, to allow current to flow through a portion of a fusible material, and when that current becomes excessive, the current is interrupted by the displacement of the fusible material. It is desirable for a current-limiting fuse to be reliable in the sense that it will necessarily interrupt the circuit when the current exceeds a predetermined maximum permissible current. Furthermore, the fuse should not interrupt the circuit at a lower current value corresponding to normal operating conditions.

[0003] Known types of fuses include a tubular insulating housing with conductive end caps at both ends. A fuse wire extending through the interior of the housing connects these two end caps. The fuse wire is sized such that it melts when a predetermined maximum permissible current flows through it. The connection between the fuse wire and the end caps can be prone to failure, meaning the connection may break at a current lower than the rated current. The higher the rated current, the more difficult it is to prevent premature triggering of such a highly reliable fuse.

[0004] The object of this invention is to provide an alternative current-limiting fuse that at least avoids the problems of the prior art. A more specific object of this invention is to provide a current-limiting fuse that is simple in structure and reliable, particularly in its reliability in interrupting large currents.

[0005] This objective is achieved by the current-limiting fuse according to claim 1.

[0006] The current-limiting fuse according to the invention comprises: an electrically insulating housing having a wall surrounding an internal space, having a first opening and a second opening opposite to the first opening; and an integrally formed electrical conductor element extending from a first terminal region outside the housing, through the first opening, through the internal space, through the second opening, and to a second terminal region outside the housing.

[0007] The conductor element includes a molten portion having a reduced cross-section. The molten portion is located within an internal space and is configured to melt when a predetermined maximum permissible current in the conductor element is exceeded. A first sealing portion of the conductor element seals a first opening, and a second sealing portion of the conductor element seals a second opening.

[0008] Because the conductor element is conductive and integrally formed, it forms a single-piece fusible element that simultaneously provides the function of a fuse terminal and closes the opening in the fuse housing. The inventors have recognized that this results in a fuse that is simple to manufacture and highly reliable.

[0009] The housing of the current-limiting fuse may not have more openings than the first and second openings. This creates a tubular topology for the housing. Once the fuse has burned, the housing prevents droplets from the molten portion from damaging adjacent components of the fuse or people nearby. The housing may be made of a material that heats up with increasing temperature when the fuse blows.

[0010] Embodiments of the present invention are directed to applications utilizing surface mount technology (SMT). At least in these cases, the housing material can be selected to withstand reflow processes at temperatures up to 260°C.

[0011] The internal space of the housing can be empty, except for the portion through which the conductor elements pass. Alternatively, the internal space can be filled with an arc-quenching material. One suitable arc-quenching material for a current-limiting fuse is sand, particularly quartz sand, designed for high maximum permissible currents, such as 100 amperes (100A) and above, for example up to 2000 amperes or even up to 10000 amperes (10kA). Therefore, the current-limiting fuse is suitable for use in high-current or ultra-high-current conditions. The latter current condition may be particularly useful because, in the near future, batteries and accumulators with short-circuit currents in this range will be available. A nominal current range of 50A to 500A and a breaking capacity of up to 10kA will be required herein and can be provided by the fuse according to the invention.

[0012] The terminal areas are spaced apart and allow the current-limiting fuse to be connected in series with the electrical device, protecting the device from overcurrent. The current-limiting fuse has two states: a conducting state and a fused state. In the conducting state, i.e., in the original unfused state, the conductor element provides electrical contact from the first terminal area to the second terminal area. Once the fuse blows, i.e., once the molten portion of the conductor element melts due to current exceeding a predetermined maximum permissible current, the electrical connection between the first and second terminal areas is interrupted. The current-limiting fuse according to the invention is a non-resettable fuse, i.e., it will not return to the conducting state. There is no reset mechanism.

[0013] The first and second terminal areas can be formed directly from conductor elements. Alternatively, they can be covered by a layer such as tin or silver, allowing the terminals to be easily soldered to the corresponding conductor pads. Alternatively, means for connecting the terminals to the corresponding conductors by soldering, threading, or riveting can be provided.

[0014] There are different options for how the first and second openings of the housing are sealed or closed by the corresponding sealing portions of the conductor element. For example, the openings can be covered by the corresponding sealing portions. As another example, the unobstructed cross-section of the opening can be completely filled by the corresponding sealing portions of the conductor element.

[0015] The reduced cross-section in the molten portion of the conductor element can be achieved by reducing the thickness of the conductor element, reducing the width of the conductor element, separating the conductor element into two or more parallel strips in the region of the molten portion, or by a combination of previously discussed possibilities, such as locally separating into two, three, or more parallel continuous strips, each strip having a reduced thickness compared to the thickness of the conductor element before and after the separation portion forming the molten portion of the fuse. By changing the number of strips and the cross-section of the strips, the current-time characteristics of the fuse can be changed according to the needs of the desired application.

[0016] In some embodiments (which will be discussed below), the term "integrally formed," as used with respect to an electrical conductor element and as used with respect to a housing, has the meaning of "formed as a single piece." This means that the conductor element or housing requires continuous material formation without joints, such as connection points, connecting lines, or connection surfaces established, for example, by welding, fusion, etc., or without mechanical interlocking connections. An integrally formed conductor element may receive its final shape, for example, by rolling, cutting, stamping, embossing, or bending.

[0017] Electrical conductor elements can be composed of metals (e.g., copper) or metal alloys (e.g., copper alloys, such as bronze or brass), silver alloys, or iron alloys (e.g., stainless steel). Suitable metal alloys with high or very high conductivity have been found in the group consisting of copper-silver alloys, copper-zirconium alloys, copper-zinc alloys, copper-magnesium alloys, copper-iron alloys, copper-chromium alloys, copper-chromium-zirconium alloys, copper-nickel-phosphorus alloys, and copper-tin alloys. Alternative metal alloys with moderate conductivity have been found in the group consisting of copper-nickel-silicon alloys, copper-beryllium alloys, copper-nickel-tin alloys, copper-cobalt-beryllium alloys, and copper-nickel-beryllium alloys.

[0018] The housing may include a polymer. It may consist of a polymer containing fillers that increase the temperature stability of the housing. The housing may be made of a ceramic material. The material of the housing may be selected such that no cracks appear in the housing under thermal shock when the maximum current is reached; high-performance thermoplastics, especially fiberglass-reinforced high-performance polyamides, such as polymer PA4T-GF30FR(40), are particularly suitable for this purpose.

[0019] Embodiments of the current-limiting fuse are derived from the features of claims 2 to 12.

[0020] In one embodiment of the current-limiting fuse according to the invention, the conductor element is a metal sheet.

[0021] The outer contour of the conductor element can be formed by stamping or cutting (e.g., laser cutting) the conductor element from a larger sheet of metal. Holes can also be drilled in the conductor element. This step can produce a molten portion with reduced width or including separate parallel extensions. The thickness of certain areas of the metal sheet can be reduced by rolling or pressing to produce a molten portion with a reduced cross-section. The metal sheet can be easily bent into the final shape, for example, bent into a shape covering the first and / or second opening of the housing. The final positioning of the terminal area can be achieved by bending the ends of the metal sheet to the desired position.

[0022] The metal sheet can be made of copper, bronze, brass, copper alloys, silver alloys, steel (especially stainless steel), etc., as discussed above in the context of suitable materials for conductor elements.

[0023] In one embodiment of the current-limiting fuse according to the present invention, the first terminal region and the second terminal region are coplanar.

[0024] Coplanar terminal areas mean that the first and second terminal areas are arranged separately from each other in a common imaginary plane. This embodiment is particularly suitable for fuses designed as surface mountable devices (SMD), i.e., suitable for leadless applications, also known as surface mount technology (SMT). The terminal areas can be arranged on the bottom side of a roughly cuboid-shaped housing and away from the housing. In this way, the current-limiting fuse can be placed on a printed circuit board, and the first and second terminal areas can be reflow soldered to pads on the printed circuit board.

[0025] Compared to the known so-called leaf spring fuses commonly used in automotive applications, the current-limiting fuses according to this embodiment have the following advantages: they can be automatically placed on printed circuit boards and can be soldered using standard reflow processes, while leaf spring fuses require manual installation, typically at the very end of the production chain, which results in relatively high costs.

[0026] In one embodiment of the current-limiting fuse according to the invention, the melting portion is mechanically self-supporting within the internal space.

[0027] Using this embodiment, an air-fuse type current-limiting fuse can be manufactured. Specifically, the fusible portion can be arranged to extend diagonally across the internal space of the housing. The combination of the dimensions of the cross-section, the geometry of the cross-section, and the materials of the conductor elements in the fusible portion can be matched so that the fusible portion is mechanically self-supporting.

[0028] In one embodiment of the current-limiting fuse according to the invention, the cross-section of the first sealing portion of the conductor element corresponds in shape and size to the cross-section of the first opening. Alternatively, or in combination with the foregoing embodiments, the cross-section of the second sealing portion of the conductor element corresponds in shape and size to the cross-section of the second opening.

[0029] For example, one of the sealing portions may have a rectangular cross-section, such as a rectangle defined by the thickness and width of the portion of the metal sheet forming the sealing portion. The dimensions of this rectangular cross-section may be set to fit precisely into the rectangular opening of the housing.

[0030] In one embodiment of the current-limiting fuse according to the invention, the second sealing portion of the conductor element has a protrusion projecting toward the internal space. The protrusion is supported on the contour portion of the second opening.

[0031] The protrusion may take the form of, for example, a raised or elongated protrusion with a rounded base, which may be imprinted into a metal sheet. Since the protrusion is supported on the contour portion of the opening, displacement of the sealing portion sealing the opening is hindered at least in the direction in which the protrusion presses against the contour portion of the opening. This embodiment is particularly suitable for use with embodiments having a large opening in the housing, which is covered by a corresponding sealing portion of the conductive element. Movement of the sealing portion in other directions (not hindered by the protrusion) can be blocked, for example, by an angled design of the conductive element extending around the edge of the housing, for example, to form a terminal region on a surface orthogonal to the surface having the protrusion.

[0032] In one embodiment of the current-limiting fuse according to the invention, the wall of the housing, the first sealing portion of the conductor element, and the second sealing portion of the conductor element together form a dustproof enclosure.

[0033] In this embodiment, the gap between the housing and the conductive element is small enough that no dust can pass through it. This prevents dust particles from entering the housing from the outside of the fuse and protects the area around the fuse from particles generated by the fuse's melting. Dust particles typically range in diameter from 5 to 100 micrometers. Therefore, the gap width can be less than 5 micrometers, or even as small as 2 micrometers or 1 micrometer, to achieve even higher levels of protection.

[0034] In one embodiment of the current-limiting fuse according to the present invention, the cross-section of the second opening is larger than that of the first opening.

[0035] This embodiment is asymmetrical in terms of the size of the opening in the housing. The assembly of the fuse can be simplified because it facilitates insertion of the conductor element from the side of the larger opening. The funnel-shaped geometry of the internal space is designed to guide one end of the conductor element through the larger second opening and through the more compact first opening; this funnel-shaped geometry can be combined with this embodiment. Due to the larger opening on one side of the housing, the conductor element can be arranged diagonally in the empty space within the housing. Thus, the length of the molten portion can be increased compared to a horizontally arranged molten portion; in particular, the molten portion can be longer than the longest side of the cuboid housing.

[0036] In one embodiment of the current-limiting fuse according to the invention, at least one recess facing the internal space is formed in the housing. Specifically, the recess may be formed in the bottom side of the housing, adjacent to the first terminal region and the second terminal region.

[0037] The inventors have recognized that, in this embodiment, a very high insulation resistance is generated between the terminals of the fuse. Therefore, the current-limiting fuse according to this embodiment has a high breaking capacity, especially for high-current applications, i.e., for rated currents up to and above 2000 amperes.

[0038] If a side exists adjacent to both the first and second terminal areas, this side is typically soldered to the printed material and is generally referred to as the bottom side. In the case where the reduced cross-section in the molten portion is formed as two or more parallel strips, the number of grooves may correspond to the number of strips, and individual grooves may extend parallel and adjacent to each strip. In use, these grooves may be arranged below the molten portion, i.e., in the direction of gravity relative to the molten portion when the fuse is in a conductive state. This results in a particularly high current breaking capacity of the fuse.

[0039] In one embodiment of the current-limiting fuse according to the invention, the geometry of the internal space is defined as the negative shape of the imaginary core, which can be completely and undamagedly removed through the second opening.

[0040] This means that in the embodiment with the aforementioned grooves, the internal space of the housing, including one or more grooves, has this geometry. The housing can be manufactured as an injection-molded polymer part or a sintered ceramic part, respectively, using an integrally formed core as part of a molded form or as part of a sintered form. An advantage of this embodiment is that the integrally formed core can be removed completely without damage, and the core can be reused. The geometry is described with reference to a hypothetical core, since the core is not actually part of the resulting housing.

[0041] In one embodiment of the current-limiting fuse according to the invention, the housing is integrally formed.

[0042] The advantage of this embodiment is that the housing is simple and inexpensive to manufacture. Furthermore, the integrally formed housing reduces the risk of tripping due to thermal shock when the fuse blows. Therefore, this embodiment is particularly suitable for high-current applications, i.e., rated currents up to and above 2000 amperes.

[0043] In one embodiment of the current-limiting fuse according to the invention, the current-limiting fuse consists of a housing and a conductor element.

[0044] The inventors have recognized that the current-limiting fuse according to the invention can be implemented with a very simple construction using only two elements: a non-conductive housing and a conductive element, the conductive element being surrounded by the housing at least in the region of the molten portion. Surprisingly, even in this simple construction, the internal space of the housing can be properly sealed, and the two parts can be properly attached to each other.

[0045] The features of the above embodiments can be combined, as long as they do not contradict each other.

[0046] Furthermore, the method according to claim 13 is within the scope of this invention. It is a method for manufacturing a current-limiting fuse according to the invention. The method according to the invention includes the following steps:

[0047] a) Provide an integrally formed electrically insulating housing having a wall surrounding an internal space, having a first opening and having a second opening opposite to the first opening;

[0048] b) Provides an integrally formed conductive element, the conductive element including a molten portion having a reduced cross-section;

[0049] c) The conductor element is introduced through the first opening or the second opening, such that the molten portion is located within the internal space; and

[0050] d) Bending the conductor element to form a first terminal region and a second terminal region outside the housing, thereby sealing the first opening through the first portion of the conductor element and sealing the second opening through the second portion of the conductor element.

[0051] Variations of this method are generated by the features of claim 14.

[0052] In this variant of the method, the conductor element provided in step a) is a metal sheet with embossed protrusions. The metal sheet has a first curved edge defining a first terminal region. The metal sheet has a second curved edge spaced apart from the protrusion by a distance that allows the curved edge and the protrusion to fit tightly between the opposing inner contours of the second opening. The metal sheet provided in step a) is flat in the region between the second curved edge and the end opposite the first terminal region.

[0053] In this variation of the method, step c) of introducing the conductor element includes feeding a flat area of ​​the conductor element (i.e., a metal sheet) through the first opening from the internal space.

[0054] In this variation of the method, step d) includes establishing a third curved edge defining the second terminal region, and then establishing a fourth curved edge adjacent to the first opening.

[0055] After the additional bending step in step d), the previously flat area of ​​the metal plate is bent, preventing the metal plate from moving backward. In this way, the housing and conductor elements constitute a mechanically stabilizing unit.

[0056] The invention will now be further illustrated with reference to the accompanying drawings. The drawings show:

[0057] Figure 1 This is the cross-section of the current-limiting fuse according to the present invention;

[0058] Figure 2.a )and Figure 2.b This is a perspective view of an embodiment of a current-limiting fuse;

[0059] Figures 3.a) to 3.d) These are different views of an embodiment of a current-limiting fuse: Figure 3.a () is a side view. Figure 3.b ) is a sectional view. Figure 3.c () is a 3D image. Figure 3.d ) is another cross section;

[0060] Figures 4a) to 4c) These are cross-sections of three different embodiments of a current-limiting fuse;

[0061] Figures 5.a) to 5.c) The diagram shows cross-sections in three different states during the manufacture of an embodiment of the current-limiting fuse shown in Figure 3.

[0062] Figure 1A cross-section of the current-limiting fuse 20 according to the invention is shown schematically and simplified. The fuse includes a conductor element 1 and a housing 2, the conductor element 1 shown by diagonal shading and the housing 2 by cross shading. The housing is an electrically insulating housing 2 having walls surrounding an internal space 6. The housing has a first opening 7 and a second opening 8 opposite to the first opening. The conductor element 1 is an integrally formed electrical conductor element. A first terminal region 3 and a second terminal region 4 are outside the housing. A molten portion 5 with a reduced cross-section (represented herein as a reduced thickness) forms the middle portion of the conductor element. The molten portion is configured to melt when a predetermined maximum permissible current in the conductor element is exceeded. The reduction in cross-section can be achieved not only by reducing the thickness but also by reducing the cross-section of a section not visible in this figure. The conductor element is formed as a single piece that extends from the first terminal region, across the first opening 7 of the housing, across the internal space 6 of the housing, across the second opening 8 of the housing, and finally to the second terminal region 4. The openings of the housing are partially sealed by the conductor element. A first sealing portion 9 of the conductor element seals the first opening 7. The second sealing portion 10 of the conductor element seals the second opening 9. In the form shown here, the first sealing portion simply fills the entire opening 7. The second opening 8 is larger than the first opening 7. The second opening is covered by the second sealing portion 10. In the form shown here, due to the specific geometry of the conductor element, the sealing portion of the conductor element is held in this position, which prevents movement in the up / down direction, where up and down refer to the directions in this figure.

[0063] Figure 2.a The diagram shows a perspective view of an embodiment of a current-limiting fuse with a specific design of housing 2 and conductor element 1. The housing, and the fuse as a whole, has an approximately cuboid shape. The housing has beveled edges. The housing has two larger extensions, namely width and length, and a smaller extension, in this case, height. A protrusion 11 is pressed into the conductor element 1, which in this embodiment is formed as a sheet of metal. The function of this protrusion will be further explained in the context of the following diagram. Terminal regions 3 and 4 are located in... Figure 2.a As can be seen in ). Figure 2.b ) showed with Figure 2.a The same fuse, but with the fuse position reversed when it may be placed on a printed circuit board. The embodiment shown here is configured as an SMD fuse suitable for reflow soldering.

[0064] Figures 3.a) to 3.d) It shows the relationship with Figure 2.a )and Figure 2.b The view is the same as the one shown in the example. Figure 3.c ) shows according to Figure 3.a ), Figure 3.b )and Figure 3.d The view orientation and the position of the cutting plane of the view. Figure 3.a The image shows a side view of housing 2 itself, i.e., without any conductor elements. The viewing direction is from... Figure 3.c Arrow A in the diagram indicates the longitudinal direction of the fuse. Here, the second opening 8 of the housing can be seen. A recess 14 is formed near the outline of opening 8. The recess is formed near the center of the opening and corresponds in shape and size to the protrusion 11 of conductor element 1, see... Figure 3.b )and Figure 3.c The combination of the recess 14 and the protrusion 11 results in a form-fit connection, preventing unwanted relative movement between the conductor element and the housing in a very simple manner. Two trapezoidal grooves 13 are formed on the bottom side of the interior space of the housing. These two grooves extend longitudinally.

[0065] Figure 3.b The figure shows a cross-section along the mid-plane of the fuse. The viewing direction of this figure is from... Figure 3.c Arrow B in the figure indicates that arrow B corresponds to the lateral direction of the fuse. Conductor element 1 passes through housing 2 and forms terminal regions 3 and 4 on the outside of the housing. The opening of the housing shown on the right side of the figure is a rectangular opening that is completely filled by the thickness of the conductor element, thus sealing the opening. The conductor element forms a first sealing portion 9 in this region. The larger opening of the housing shown on the left side of the figure is covered by a second sealing portion 10. Protrusion 11, together with the inclined portion located above the second sealing portion 10 and with the inclined portion adjacent to the first terminal region 3, holds the sealing portion in place relative to the lateral and height positions of the housing. The molten portion 5 of the conductor element is formed as two parallel strips, the width of which is significantly reduced compared to the width of the conductor element before and after the molten portion 5. In the illustrated embodiment, the cross-section of the conductive material in the molten portion is reduced to approximately 15% of the total cross-section.

[0066] Figure 3.d ) shows from by Figure 3.c The cross-section is shown in the top direction, indicated by arrow D. The cutting plane is a horizontal plane located directly below the upper limit of the internal space of the housing. Conductor element 1 is viewed from the top. On the left side of the figure, conductor element 1 has full width and full cross-section. The central cut and the two side cuts reduce the conductive element to two parallel strips, which form the molten portion 5 of the conductor element. Each of the two strips extends parallel to one of the grooves 13. On the right side of the figure, the cutting plane intersects the wall of the housing. Figure 3.b As shown in the figure, the internal space of the shell has a funnel shape in this region.

[0067] Figure 4.a ) shows the corresponding Figure 1This is an embodiment of a current-limiting fuse. The conductor element 1 and its molten portion 5 extend diagonally through the internal space of the housing. The first terminal region 3 and the second terminal region 4 are coplanar, i.e., located in a common imaginary plane 12, which is represented by a dashed line in this cross-section. This embodiment is suitable as an SMD fuse.

[0068] Figure 4.b A variation of the embodiment with two openings of approximately equal size is shown. The conductor element extends horizontally through the interior space. The terminal portions are bent to the same side, such that, also in this variation, the two terminal regions 3, 4 lie in a common imaginary plane 12.

[0069] Figure 4.c Another variation is shown, in which the terminal portions are bent to different sides of the fuse. In this way, terminal regions 3 and 4 are defined on opposite sides of the fuse, allowing the fuse to be used like a tube fuse.

[0070] Figure 5.a The diagram shows the state after the initial conductor element 1 has been inserted into the housing 2. The curved edge on the left and the embossed protrusion can be prepared before the insertion step. In the state shown, both openings of the housing have been sealed. The flat portion of the metal sheet forming the conductor element protrudes from the housing by a distance d1 on the right side of the diagram.

[0071] Figure 5.b The diagram shows the state after the additional bending step. The position and angle of the other bending edge can be specified by distances d2, d3, d4 and angle α, as shown in the table below.

[0072] Figure 5.c This figure shows an optional intermediate state after the further bending step and before the second terminal reaches its final position on the bottom side of the housing. Another bent edge is created near the smaller opening in the housing on the right side of this figure. The geometry is specified by distances d5 and d6 and angle β, see the table below.

[0073] As an example, the following distances and angles can be applied:

[0074] d1(mm) d2(mm) d3(mm) d4(mm) d5(mm) d6(mm) α β 3.91 2.01 2.07 2.2 1.53 2.19 90° 130°

[0075] Angle α can be intentionally made slightly smaller than a right angle, for example, 0.5° to 3° smaller, so that a press fit is achieved once the terminal portion is in its final position on the underside of the fuse.

[0076] List of reference numerals

[0077] 1 Conductor element

[0078] 2. Shell

[0079] 3 First terminal area

[0080] 4 Second terminal area

[0081] 5. Melted portion

[0082] 6. Interior Space

[0083] 7 (of the shell) First opening

[0084] 8 (Second opening of the shell)

[0085] 9 (of the conductor element) First sealing portion

[0086] 10 (Second sealing part of conductor element)

[0087] 11 (Protrusions of conductor elements)

[0088] 12. Imaginary plane (including two terminal areas)

[0089] 13 Grooves

[0090] 14 concavity

[0091] 20 Current-limiting fuses

[0092] d1, d2, d3, d4, d5, and d6 are used to define the dimensions of the bending process according to the embodiment.

[0093] α, β are used to define the angles of the bending process according to the embodiment.

Claims

1. A current limiting fuse (20), comprising: an electrically insulating housing (2) having a wall surrounding an interior space (6), having a first opening (7) and having a second opening (8) opposite the first opening; and a conductive, integrally formed conductor element (1) extending from a first terminal area (3) outside the housing, across the first opening, across the interior space, across the second opening, to a second terminal area (4) outside the housing, wherein the conductor element comprises a melting portion (5) having a reduced cross section, the melting portion being located in the interior space and being configured to melt when a predetermined maximum permissible current in the conductor element is exceeded, and wherein a first sealing portion (9) of the conductor element seals the first opening (7), and wherein a second sealing portion (10) of the conductor element seals the second opening (8), wherein the second sealing portion (10) of the conductor element has a protrusion (11) projecting towards the interior space (6), the protrusion being supported on a profile portion of the second opening (8), and wherein the conductor element (1) is formed from a metal sheet, wherein the protrusion (11) is stamped into the metal sheet, and wherein the metal sheet has a curved edge spaced apart from the protrusion (11) by a distance allowing the curved edge and the protrusion (11) to fit tightly between opposing inner profiles of the second opening (8), thereby providing the second sealing portion (10). The first terminal area (3) and the second terminal area (4) are coplanar.

2. The current-limited fuse of claim 1, wherein, The melting portion (5) is mechanically self-supporting in the interior space (6).

3. The current-limited fuse of claim 1 or 2, wherein, A cross section of the first sealing portion (9) of the conductor element corresponds in shape and size to a cross section of the first opening (7), and / or wherein a cross section of the second sealing portion (10) of the conductor element corresponds in shape and size to a cross section of the second opening (8).

4. The current-limited fuse of claim 1 or 2, wherein, The wall of the housing (2), the first sealing portion (9) of the conductor element and the second sealing portion (10) of the conductor element together form a dust barrier.

5. The current-limited fuse of claim 1 or 2, wherein, A cross section of the second opening (8) is larger than a cross section of the first opening (7).

6. The current-limited fuse of claim 1 or 2, wherein, At least one recess facing the interior space is formed in the housing.

7. The current-limited fuse of claim 1 or 2, wherein, The recess is formed in a bottom side of the housing, the bottom side being adjacent to the first terminal area and the second terminal area.

8. The current-limited fuse of claim 7, wherein, A geometry of the interior space (6) is defined as a negative shape of a hypothetical core, the hypothetical core being completely and intact removable through the second opening (8).

9. The current-limited fuse of claim 1 or 2, wherein, The housing (2) is integrally formed.

10. The current-limited fuse of claim 1 or 2, wherein, The current limiting fuse consists of the housing (2) and the conductor element (1).

11. The current-limited fuse of claim 1 or 2, wherein, 12. A method of manufacturing a current limiting fuse according to any one of claims 1 to 11, the method comprising the steps of: ​ a) providing (101) the electrically insulating housing (2) as a unit, the electrically insulating housing (2) having a wall surrounding the interior space (6), having the first opening (7) and having the second opening (8) opposite the first opening; b) providing (102) the electrically conductive conductor element (1) as a unit, the conductor element (1) comprising the melting portion (5) having a reduced cross section; c) introducing (103) the conductor element (1) through the first opening (7) or through the second opening (8) so that the melting portion (5) is located in the interior space (6); d) bending the conductor element (1) to form the first terminal area (3) and the second terminal area (4) outside the housing (2), thereby sealing the first opening (7) by the first sealing portion (9) of the conductor element (1) and sealing the second opening (8) by the second sealing portion (10) of the conductor element (1), wherein the conductor element (1) provided in step b) is a metal sheet having an embossed protrusion (11), wherein the metal sheet has a first bent edge delimiting the first terminal area, wherein the metal sheet has a second bent edge spaced apart from the protrusion by a distance allowing the second bent edge and the protrusion to fit tightly between opposite inner contours of the second opening, wherein the metal sheet is flat in a region between the second bent edge and an end opposite the first terminal area, wherein the step c) of introducing the conductor element comprises feeding the flat region of the conductor element from the interior space through the first opening, wherein step d) comprises establishing a third bent edge delimiting the second terminal area and then establishing a fourth bent edge adjacent the first opening.

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