Fuses and methods for manufacturing fuses

Abstract

The present invention relates to a fuse (1), particularly an SMD fuse, comprising: an insulator (2) open at the end face; at least one molten conductor (3) disposed within the insulator (2); at least one auxiliary cap (4) electrically contacted to the molten conductor (3) for at least partially covering the end face (5) of the insulator (2); and an outer cap (6) assigned to the auxiliary cap (4) for at least partially, preferably completely covering the auxiliary cap (4) and electrically contacted to the auxiliary cap (4). According to the present invention, the auxiliary cap (4) has a housing portion (8) protruding into the interior (7) of the insulator (2), the housing portion (8) having a through-opening (9) protruding into the interior (7) of the insulator (2), through which the end region (10) of the molten conductor (3) is led, and the end region (10) of the molten conductor (3) is electrically contacted to the auxiliary cap (4) materially via a particularly lead-free connecting means (11) disposed within the housing portion (8), and the outer cap (6) covers the auxiliary cap (4) such that the connecting means (11) is captured and / or encapsulated between the auxiliary cap (4) and the outer cap (6).

Description

Technical Field

[0001] The present invention relates to fuses, particularly SMD fuses and / or device protection fuses, comprising an insulator open on the end face side, at least one melting conductor arranged within this insulator, at least one auxiliary cap for at least partially covering the end face of the insulator and being electrically contact-connected to this melting conductor, and an outer cap assigned to this auxiliary cap, at least partially covering this auxiliary cap and being electrically contact-connected to this auxiliary cap. Furthermore, the present invention relates to a method for manufacturing a fuse in the above-described form.

[0002] A fuse or device protection fuse in the sense of the present invention is also called a so-called "fuse insert" in the prior art, which may interact with a fuse holder. In this case, this fuse insert may be inserted into the fuse holder.

[0003] If necessary, the fuse or fuse insert is filled with an arc extinguishing agent, particularly sand, granules and / or glass beads, and in particular, the arc extinguishing agent is arranged within the insulator. This insulator may be formed as an insulating tube. The melting conductor is actually inserted axially into the insulator. The electrical contact between the melting conductor and the outer contact cap attached to the insulating housing is carried out by brazing. Furthermore, this brazing also connects the outer contact cap to the insulator in a material-connecting manner.

[0004] The melting conductor is configured to carry the full load current during operation and to interrupt overload currents and / or short-circuit currents as quickly as possible.

[0005] Fuse inserts that can be mounted on the surface of a printed circuit board are called SMD (Surface Mounted Device) fuses. Therefore, SMD fuses belong to the field of Surface Mount Technology (SMT). In this surface mount technology, printed circuit boards are commonly used as the mounting surface. In particular, SMD fuses are standardized in terms of their dimensions and electrical behavior (see DIN EN 60127-4 VDE 0820-4:2013-12 (as of March 2023) for details).

[0006] Known fuses based on prior art have a drawback in some fuses where the molten conductor is displaced or shifted within the insulator during fuse manufacturing (after insertion of the molten conductor into the insulator). Ultimately, the molten conductor ceases to remain in the assembly position provided for it. Consequently, during fuse assembly, the molten conductor may come into contact with or even rub against the inner wall of the insulator. When the molten conductor is displaced in this way within the insulator, the switching characteristics of the entire fuse change, and in particular, they no longer correspond to the specified value. This is extremely disadvantageous because each fuse is designed for a specified value and is used in accordance with that value. Therefore, deviations from the specified value must be avoided at all costs.

[0007] Indeed, after a fuse is manufactured, a fuse with a "displaced" molten conductor can be deemed unsuitable by optical inspection. However, this method is relatively time-consuming and costly, especially since it requires optical inspection of each individual fuse. Furthermore, this optical inspection can only be performed before the outer contact cap is attached, particularly based on opaque insulators. However, if displacement of the molten conductor occurs after or during the attachment of the outer contact cap, this can no longer be optically confirmed.

[0008] Furthermore, known fuses based on the prior art, or known methods for manufacturing fuses based on the prior art, have the drawback that the connection of the molten conductor by brazing to electrically contact the outer contact cap is often insufficient for a lasting electrical connection. In particular, the formation of a so-called "solder ball" (a ball made of solder material) is necessary for electrical contact between the molten conductor and the outer contact cap, however, this no longer guarantees a sufficient connection. That is, the solder or solder material escapes into the intermediate chamber between the outer contact cap and the insulator, and consequently, there is no longer enough solder between the molten conductor and the outer contact cap for a sufficient electrical connection.

[0009] Therefore, the object of the present invention is to avoid or at least substantially reduce the aforementioned drawbacks of the prior art. In particular, the object of the present invention is to ensure reliable and sustained positioning of the molten conductor within the insulator.

[0010] According to the present invention, the aforementioned problems are solved by the fuse described in claim 1.

[0011] The fuse according to the present invention is formed in particular as an SMD fuse or an equipment protection fuse. The fuse has an insulator that is open at the end faces, that is, open at both end faces in particular. Distributed within the insulator is at least one molten conductor, which may be formed as a molten conductor wire. Furthermore, the fuse comprises at least one auxiliary cap electrically contact-connected to the molten conductor. This auxiliary cap is configured to partially cover at least the end faces of the insulator. Furthermore, the auxiliary cap is assigned an outer cap that at least partially, preferably completely, covers the auxiliary cap and is electrically contact-connected to the auxiliary cap.

[0012] Naturally, additional auxiliary caps and / or additional outer caps may be provided. In particular, the insulator is covered at both of its end faces first by an auxiliary cap and then by an outer cap. However, the present invention is not limited to two auxiliary caps and / or two outer caps, and may already be realized with one auxiliary cap and / or outer cap.

[0013] According to the present invention, the auxiliary cap is specified to have a housing portion protruding into the interior of the insulator, and this housing portion has a through-opening protruding into the interior of the insulator. The end region of the molten conductor may be led through this through-opening, or in the fully fabricated state of the fuse, the molten conductor is led through the through-opening at its end region.

[0014] The end region of the molten conductor is electrically contacted materially to the auxiliary cap via a particularly lead-free connecting means located within the housing. The outer cap covers the auxiliary cap such that the connecting means is captured and / or encapsulated between the auxiliary cap and the outer cap.

[0015] The connecting means are positioned within the housing in such a way that they cannot penetrate from the housing into the interior of the insulator and / or extend beyond the outer cap. Particularly preferred is that even during later melting and / or liquefaction of the connecting means, the intrusion or escape of the connecting means into the insulator can be avoided at least substantially reliably. Therefore, the connecting means are encapsulated within the housing.

[0016] In this regard, the housing may, of course, be partially or completely filled with connecting means. Finally, the connecting means are arranged within the housing in such a way as to ensure the secure and permanent positioning of the molten conductor.

[0017] Therefore, according to the present invention, the auxiliary cap, through a housing having a through-opening, provides the possibility of ensuring a simplified arrangement of connecting means for maintaining contact with the molten conductor.

[0018] The connecting means may have a variety of forms and / or structures. Therefore, the connecting means may be specified to be liquefied and / or melted for material-connective connection to the molten conductor. Furthermore, solder may be provided as the connecting means. However, the connecting means may be specified to be provided as a covering for the molten conductor. In this case, the covering is material-connectively and / or electrically contactively connected to an auxiliary cap.

[0019] The connecting means is particularly preferably connected to the auxiliary cap and the end region of the molten conductor in a material-connective manner. However, the connecting means may be connected to the auxiliary cap in another form, particularly in a shape-connective and / or friction-connective manner. In particular, the connecting means is specified to ultimately ensure an electrical connection between the molten conductor and the auxiliary cap, and furthermore, to ensure the positioning of the molten conductor.

[0020] The connecting means can ensure a continuous electrical contact of the molten conductor, and in this case, the connecting means can also ensure the positional stable placement of the molten conductor within the insulator. Thus, the housing constitutes a placeable portion for the connecting means, and further, it allows the connecting means to "remain" within the fuse only in a predetermined area. In this way, it is possible to avoid the connecting means reaching, for example, into the interior of the insulator. The connecting means may be connected to the outer cap, but is not required. The electrical connection between the end region of the molten conductor and the outer cap is achieved, in particular, via an auxiliary cap. Thus, the auxiliary cap allows for, firstly, a relatively simple placement of the connecting means, and secondly, simple contact of the molten conductor.

[0021] Despite the housing having a through-opening, the auxiliary cap is configured, particularly preferably, to prevent the connection means from escaping into the insulator and, consequently, beyond the through-opening. The connection means does not extend into the insulator, particularly beyond the through-opening, thereby the through-opening, despite its configuration as an opening, forms a demarcation for the connection means. In this case, the auxiliary cap and housing are configured to prevent such intrusion of the connection means into the insulator. Therefore, the through-opening is useful for guiding the end region of the molten conductor through, but not for guiding the connection means. Ultimately, the secure positioning of the molten conductor, also achieved particularly by the connection means, reliably prevents the molten conductor from leaning against the inner wall of the insulator. The end region of the molten conductor can be fixed immovably and permanently by the connection means, and this positioning can withstand high loads.

[0022] In preferred embodiments, the molten conductor is specified to terminate within a housing inside the insulator and / or be positioned without contact with the outer cap and / or auxiliary cap. Particularly preferred is that the molten conductor is not directly adjacent to the wall of the outer cap, the wall of the auxiliary cap and / or the wall of the insulator, in which case electrical contact of the molten conductor with the outer cap can ultimately be ensured through the arrangement of connecting means within the auxiliary cap.

[0023] The aforementioned configuration ensures the orderly and continuous use of the fuse. In particular, it helps to avoid many defects during fuse production. This is because precise alignment of the contact of the molten conductor with the auxiliary or outer cap is unnecessary, and reliable and continuous electrical contact can be ensured through the connecting means located within the housing.

[0024] Preferably, the length of the molten conductor is less than or equal to the length of the insulator. The molten conductor may be placed in the insulator in a particularly straight, preferably elongated, state. However, in a further embodiment, the molten conductor can also be provided in the insulator, for example, wrapped around a coil. In this case, although the length of the molten conductor is longer than the length of the insulator, this is not necessarily required. A shorter length of the molten conductor ensures less material consumption of the molten conductor, which is significant for economic reasons.

[0025] Particularly preferable, the end region of the molten conductor is completely enclosed by the connecting means.

[0026] In further embodiments, at least one portion of the end region may protrude beyond the connecting means, in particular, so that the entire end region of the molten conductor is not confined by the connecting means.

[0027] By completely enclosing the end region of the molten conductor with the connecting means, it is possible to ensure that the molten conductor is securely fixed in place and that long-term electrical contact of the end region of the molten conductor can also be guaranteed. Therefore, the connecting means ensure that the molten conductor is fixed in place within the insulator.

[0028] In a further preferred embodiment of the present invention, the connecting means is specifically located exclusively within the area of ​​the housing. The housing ultimately constitutes an area of ​​the fuse that can be used for the connecting means. In this case, the connecting means has the function of fixing the molten conductor in place and electrically connecting it to the outer cap via an auxiliary cap. For this reason, it is unnecessary to place the connecting means outside the housing, and thus, for material-saving reasons, simply placing it inside the housing becomes advantageous.

[0029] Preferably, the through-opening has an opening width of at least 0.1 mm. Particularly preferably, the opening width of the through-opening is 0.1 mm to 6 mm, preferably 0.5 mm to 5 mm, more preferably 0.8 mm to 2.4 mm, and particularly 1.1 mm to 1.5 mm. With the through-opening width within the above-mentioned range, on the one hand, the end region of the molten conductor can pass through the through-opening, and on the other hand, it is possible to avoid the connecting means escaping into the interior of the insulator even in the liquefied state over the through-opening.

[0030] Particularly preferably, in a further embodiment, it is specified that the opening is formed as a V-shaped depression and / or a frustum-conical recess. The frustum-conical recess or at least a substantially frustum-conical recess can also be regarded as a depression. The frustum-conical recess enables relatively easy insertion and placement of the connecting means into the receiving portion. Preferably, the opening angle of the recess formed preferably as a frustum (i.e., particularly the angle that is twice the angle between the generatrix and the frustum axis) is 10° to 100°, preferably 20° to 90°, and more preferably 50° to 70°. Therefore, the opening angle can ensure a depression that increases towards the end face of the insulator. Such a depression shape provides the advantage that the encapsulation of the connecting means can be achieved relatively easily. This is because the depression tapers towards the interior of the insulator, whereby the connecting means are finally encapsulated within the receiving portion.

[0031] In a further embodiment, it is particularly preferred that the connecting means located within the receiving portion is in direct contact with the inner wall of the outer cap facing the interior of the insulator.

[0032] In an alternative embodiment, it may be specified that the connecting means is merely indirectly arranged on the outer cap and is in electrical contact with the outer cap via an auxiliary cap.

[0033] Direct contact with the outer cap allows the connecting means to make direct electrical contact with the outer cap, thus ensuring, firstly, electrical contact between the outer cap, the connecting means, and the molten conductor during current guidance, and secondly, through the auxiliary cap, which ultimately provides the advantage of offering "double protection."

[0034] Furthermore, the housing may be filled at least substantially completely with connecting means. Alternatively or additionally, it may be specified that at least 20%, preferably at least 30%, more preferably at least 40%, and especially 30% to 80%, of the volume of the housing is filled with connecting means, particularly solder. Partially filling the housing offers the advantage of providing a smaller amount of connecting means, especially when using connecting means which would incur high material costs. Thus, for example, gold-containing connecting means can be used.

[0035] In a further preferred embodiment, the outer cap is specified to be connected to the auxiliary cap via a press fit. Alternatively or additionally, the outer cap may be specified to be connected to the auxiliary cap via at least one crimp connection, in particular four crimp connections. The aforementioned forms of connection allow for a fixed fit of the outer cap to the auxiliary cap without requiring any additional adhesive connections or similar. It also avoids screw fastening, which may in some cases damage the insulating housing. The press fit and / or crimp connection between the auxiliary cap and the outer cap ensures a stable, particularly form-conductive and / or friction-conductive connection that can withstand long-term loads, especially when used as a fuse.

[0036] Preferably, the auxiliary cap has a circumferential surface that surrounds the wall of the insulator. The auxiliary may be connected to the wall of the insulator particularly by friction connection. Alternatively or additionally, the circumferential surface of the auxiliary cap may have at least one locking leg projecting from the end, preferably extending around the entire circumference, which is specified to engage with the underside of the outer cap. Thus, the locking leg can be used for improved coupling and connection of the outer cap. As a result, locking is particularly preferably possible. The circumferential surface may be formed integrally, particularly preferably. Particularly preferably, the locking leg is configured to extend around the entire circumference surrounding the insulator and to project beyond the insulator.

[0037] Furthermore, in a more preferred embodiment, the outer cap may be configured to completely cover the end face of the insulator. Thus, the outer cap can protect the interior of the insulator from external influences, thereby ensuring its use as an SMD fuse. Preferably, the outer cap has an outer circumferential surface that at least indirectly surrounds the wall of the insulator and is preferably connected by friction to the circumferential surface of the inner auxiliary cap, and is connected at least indirectly, particularly by friction to the wall of the insulator. Particularly preferably, the outer circumferential surface of the outer cap is locked to the locking legs of the auxiliary cap. The outer circumferential surface of the outer cap may particularly at least substantially completely cover or cover the circumferential surface of the auxiliary cap, thereby allowing the auxiliary cap to be covered by the outer cap from the outside. The outer circumferential surface and the inner circumferential surface of the auxiliary cap may preferably be electrically connected to each other by at least substantially direct contact.

[0038] Preferably, the connecting means may have and / or consist of solder and / or a conductive adhesive, particularly a silver conductive adhesive, as its material. Alternatively or additionally, the connecting means may be formed as a conductive covering, particularly a tin covering, surrounding the end region of the molten conductor. In this configuration, of course, the tin covering in particular can be considered as a connecting means that can surround the end region of the molten conductor, which may also be a wire. In this case, the tin covering may be configured to connect the molten conductor wire and the auxiliary cap to each other.

[0039] The connecting means may be used to connect to the molten conductor in a variety of states or forms. Therefore, the connecting means, in particular the solder, may be formed before melting as wire, solder paste, pellets, or molded members. Alternatively or additionally, the solder may be specified to be lead-free. Lead-free configurations are particularly advantageous with respect to standards and regulations to be observed. Finally, various forms of connecting means may be used to electrically connect the end regions of the molten conductor to the auxiliary cap and / or outer cap. However, it is particularly preferable to use solder as the connecting means, which can be provided in various forms. All connecting means have in common that they can ensure electrical contact of the molten conductor by a fixed-position coupling of the molten conductor to the auxiliary cap. Various materials known in practice may be used as solder. In particular, gold alloys may be used as solder.

[0040] In a further preferred configuration of the inventive concept, the auxiliary cap is specified to have a bridging region connecting the circumferential surface to the housing. This bridging region is, in particular, at least partially resting on the end face of the insulator wall and preferably protruding beyond the wall. Alternatively or additionally, the bridging region may be specified to protrude so as to extend circumferentially with respect to the insulator wall. Thus, the bridging region can be used in combination with the recess configuration to ensure bridging between the circumferential surface and the recess. The bridging region may also function for contact with the outer cap and, consequently, for electrical contact of the outer cap. Thus, it is ensured that the bridging region can provide various shapes with respect to the recess, regardless of the circumferential surface configuration.

[0041] Preferably, the housing portion may have a further opening opposite the through-opening protruding into the interior of the insulator. This further opening may preferably be formed at least substantially circularly. In particular, the area of ​​the further opening is 30% to 90%, preferably 50% to 80%, and more preferably 60% to 75%, of the area of ​​the open end face of the insulator. The through-opening may preferably form the top surface (i.e., the cut surface) of a depression formed as a frustocone, and the further opening may form the bottom surface. In this case, the area of ​​the through-opening may be smaller than the area of ​​the further opening. Thus, the molten conductor can be introduced into the interior first through the further opening and then through the through-opening. In this case, a depression circumferential surface may be arranged between the through-opening and the further opening, where the end region of the molten conductor may be adjacent. Thus, the depression can be formed and preferably defined by the depression circumferential surface, the through-opening, and the further opening.

[0042] In particular, the interior of the insulator is filled at least partially with an arc extinguishing agent, especially arc extinguishing sand. This arc extinguishing agent may be provided specifically to extinguish the arc.

[0043] The arc extinguishing agent may include arc extinguishing sand having a specified particle size distribution, which is particularly suitable for use in fuse inserts. Furthermore, colored sand, sand chips and / or ceramic chips and / or glass spheres may be used as the arc extinguishing agent.

[0044] Preferably, a different material may be used for the arc extinguisher. However, the arc extinguisher is configured in particular to be able to extinguish the arc during operation. A material suitable for this purpose can be used as the arc extinguisher.

[0045] The insulator may be formed in particular as an insulating tube. In this case, preferably, the molten conductor may be inserted into the insulator through further openings and through-openings in the axial direction.

[0046] If arc-extinguishing sand is provided as an arc-extinguishing agent, quartz sand may be particularly preferred. As mentioned above, the arc-extinguishing agent makes it possible to extinguish the arc when the fuse is activated, thereby improving the overall safety and / or switching ability and / or switching performance of the fuse.

[0047] A molten conductor may have and / or be made of a conductive material, preferably a metal. Copper, nickel, steel, gold, and / or silver are particularly used as materials for molten conductors. Furthermore, a molten conductor may have a metal alloy as its material, such as a silver alloy and / or a copper alloy.

[0048] The molten conductor may be formed as a molten conductor wire and / or a molten conductor ribbon. Furthermore, the molten conductor may have at least a substantially circular and / or elliptical cross-section or at least a substantially rectangular cross-section.

[0049] Furthermore, the molten conductor may be provided with a narrow section, which can be used to adjust for more rapid or slower overload behavior and / or short-circuit behavior. In this case, the narrow section may be formed in particular as a cross-sectional narrow section.

[0050] Furthermore, the insulator may have an electrically insulating material, such as glass and / or ceramics, and / or be made of an electrically insulating material, such as glass and / or ceramics.

[0051] Preferably, the molten conductor may be completely contained within the insulator, in which case external contact of the molten conductor may be made via an outer cap. This ensures that the SMD fuse can be easily placed on the printed circuit board.

[0052] In particular, the molten conductor may be centered within the insulator, which is especially advantageous for the behavior of the fuse.

[0053] Alternatively or additionally, the insulator may have and / or be made of plastic as a material. In particular, electrically insulating materials are provided as materials for the insulator.

[0054] Preferably, there is a further auxiliary cap, which is in contact with the molten conductor and covers at least partially the other end face of the insulator, and a further outer cap, which is assigned to the further auxiliary cap and covers at least partially, preferably completely, the further auxiliary cap and is electrically in contact with the further auxiliary cap.

[0055] In this regard, the above-mentioned description of the auxiliary cap and / or outer cap may, of course, be referenced with respect to configurations for further auxiliary caps and / or further outer caps, because further auxiliary caps and / or further outer caps may also be provided with the above-mentioned features.

[0056] Ultimately, it is possible to provide two auxiliary caps and two outer caps in the configuration described above.

[0057] It is particularly preferable that the auxiliary cap and further auxiliary cap, as well as the outer cap and further outer cap, are formed with at least substantially the same structure. However, the auxiliary cap and further auxiliary cap, or the outer cap and further outer cap, may be formed with different structures from each other. In this case, preferably, the auxiliary cap and outer cap, as well as the further auxiliary cap and further outer cap, are harmonized with each other so as to ensure electrical contact of the molten conductor through each outer cap. Even when the auxiliary cap and further auxiliary cap, or the outer cap and further outer cap, are formed with different structures from each other, the above description may, of course, be referred to in this regard, because the same configuration can be applied to the further auxiliary cap and further outer cap.

[0058] Furthermore, the present invention relates to a method for manufacturing a fuse according to one embodiment of the plurality of embodiments described above, preferably carried out sequentially. A) A step of preparing an insulator, at least one auxiliary cap, at least one outer cap, and at least one molten conductor, B) Step of attaching the auxiliary cap to one end face of the insulator, C) Optionally, attach an additional auxiliary cap to the other end face of the insulator. D) A step of introducing the molten conductor into the interior of the insulator, particularly through the through-opening of the housing portion of the auxiliary cap, E) Connecting the auxiliary cap to the molten conductor by arranging the connecting means within the housing of the auxiliary cap, thereby electrically connecting the auxiliary cap to the molten conductor. F) Optionally, rotate the insulator by a range of 100° to 200°, preferably about 180°. G) Optionally, the step of introducing an arc extinguishing agent, preferably through an uncovered end face and / or further housing of an auxiliary cap that is not yet filled by a connecting means, H) Step of covering the auxiliary cap with the outer cap for electrical contact. This includes methods.

[0059] In relation to the method according to the present invention, the aforementioned preferred embodiments and advantages of the fuse according to the present invention may be referenced, and such embodiments and advantages apply similarly to the method according to the present invention without requiring any further explicit reference. At the same time, the method features and advantages described below also apply similarly to the fuse according to the present invention as described above. Therefore, to avoid unnecessary repetition, please refer to the following description and the above description.

[0060] In a particularly preferred embodiment of the method according to the present invention, it is specified that, preferably after step F and / or after step G and / or H, the connecting means is placed in a further housing of the further auxiliary cap, thereby connecting the further auxiliary cap to the molten conductor, and thereby electrically connecting the further auxiliary cap to the molten conductor.

[0061] In particular, an additional auxiliary cap may be covered by an additional outer cap for electrical contact, and preferably permanently connected to the outer cap.

[0062] Furthermore, the connecting means may be heated, particularly melted, after being placed in the housing, thereby creating an electrical connection and immovable position fixation between the connecting means and the molten conductor, and between the molten conductor and the auxiliary cap, particularly preferably. In particular, heating of the connecting means already placed in the housing is carried out by flame, resistance brazing, laser brazing, hot air, and / or induction. The aforementioned methods for heating the connecting means have been found to be particularly advantageous and accurate in tests performed during the realization of the invention to ensure a secure bond. Alternatively or additionally, the connecting means, particularly the solder, may be formed in the form of wires, as solder paste, as pellets, or as molded members before heating and / or melting.

[0063] Furthermore, naturally, the aforementioned intervals and range boundaries include their respective intermediate intervals and individual values, and even if these intermediate intervals and individual values ​​are not specifically described, they must be considered as essential disclosures for the present invention.

[0064] Further features, advantages, and applicability of the present invention will become apparent from the following description of embodiments based on the drawings and from the drawings themselves. In this case, all features described and / or illustrated, regardless of their grouping in the claims or reference relationships, constitute the subject matter of the present invention, either individually or in any combination. [Brief explanation of the drawing]

[0065] [Figure 1] This is a schematic perspective view of the fuse according to the present invention. [Figure 2] Figure 1 is a schematic perspective cross-sectional view of the fuse shown. [Figure 3] This is a schematic further cross-sectional view of the fuse shown in Figure 1. [Figure 4] This is a schematic perspective view of the fuse shown in Figure 1 without the outer cap. [Figure 5] This is a schematic perspective cross-sectional view of the fuse shown in Figure 4, without the outer cap. [Figure 6] This is a schematic further cross-sectional view of the fuse shown in Figure 4 without the outer cap. [Figure 7] This is a schematic perspective view of an auxiliary cap according to the present invention. [Figure 8] Figure 7 is a schematic perspective cross-sectional view of the auxiliary cap. [Figure 9] Figure 7 is a schematic further cross-sectional view of the auxiliary cap. [Figure 10] This is a schematic diagram of the method according to the present invention for manufacturing a fuse according to the present invention.

[0066] Figure 1 shows fuse 1, which may be formed as an SMD fuse. Its use as an SMD fuse is not illustrated in detail.

[0067] Figures 2 and 3 show cross-sectional views of fuse 1 as shown in Figure 1.

[0068] Figure 2 clearly shows that the fuse 1 has an insulator 2 that is open at the end face. In the embodiment shown in Figure 2, this insulator 2 is open at both end faces. Figure 1 shows an insulator 2 that is at least substantially rectangular in shape.

[0069] In further embodiments, various forms of the insulator 2 may be used, for example, a tubular configuration of the insulator 2.

[0070] Figures 2 and 3 show that a molten conductor 3 is arranged within an insulator 2. This molten conductor 3 is sometimes called a molten conductor wire. Furthermore, an auxiliary cap 4 is provided, electrically connected to the molten conductor 3. In the embodiments shown in Figures 2 and 3, two auxiliary caps 4, 22, formed of the same structure as each other, are particularly preferred. Although not shown, only one auxiliary cap 4 may be used. The fuse 1 further comprises an outer cap 6. This outer cap 6 is assigned to the auxiliary cap 4 and covers or encloses the auxiliary cap 4 at least partially, preferably completely. The outer cap 6 is electrically connected to the auxiliary cap 4. Furthermore, this auxiliary cap 4 covers at least partially the end face 5 of the insulator, as shown in Figure 3.

[0071] Figure 4 shows the fuse shown in Figure 1 without the outer cap 6. Naturally, two outer caps 6,23 may be used. In the illustrated embodiment, both outer caps 6,23 are formed with at least substantially the same structure. Although not shown, only one outer cap 6 may be provided.

[0072] Figures 5 and 6 show cross-sectional views of the fuse 1 shown in Figure 4 without the outer cap 6.

[0073] Figure 2 shows that the auxiliary cap 4 has a housing portion 8 that protrudes into the interior 7 of the insulator 2, and this housing portion 8 has a through-opening 9 that protrudes into the interior of the insulator 2, through which the end region 10 of the molten conductor 3 is guided.

[0074] Figure 3 further shows that the end region 10 of the molten conductor 3 is electrically contacted materially to the auxiliary cap 4 via a particularly lead-free connecting means 11 located within the housing 8. The connecting means 11 is located at least partially within the housing 8. Although Figure 2 shows that the housing 8 is filled at least substantially completely with the connecting means 11, this is not necessarily required. The housing 8 without the connecting means 11 is shown in Figure 7. In this case, Figures 8 and 9 show a cross-sectional view of the auxiliary cap 4 shown in Figure 4.

[0075] Figures 2 and 3 clearly show that the outer cap 6 covers the auxiliary cap 4 such that the connecting means 11 is captured and / or encapsulated between the auxiliary cap 4 and the outer cap 6.

[0076] The connecting means 11 is positioned within the housing 8, in particular, so as not to penetrate the interior 7 of the insulator 2, that is, beyond the through-opening 9 of the housing 8. The through-opening 9 specifically forms a demarcation for the connecting means 11. Thus, the housing 8 is molded or formed in such a way that it can ensure the encapsulation and / or capture of the connecting means 11 within the housing 8.

[0077] The connecting means 11 is contained and / or encapsulated within the housing 8, even when the fuse 1 is heated, and is particularly preferably prevented from penetrating beyond the through-opening 9 into the interior 7 of the insulator 2.

[0078] Figure 2 shows that the molten conductor 3 terminates within the housing 8 inside the insulator 2 and is positioned without contact with the outer cap 6 and the auxiliary cap 4. In further embodiments, the molten conductor 3 may be specified to be in contact with and / or abutting the auxiliary cap 4, the outer cap 6 and / or the housing 8. Electrical contact of the molten conductor 3 is ensured via the connecting means 11 in the embodiment shown in Figure 2.

[0079] In the embodiment shown in Figure 2, it is further specified that the length 12 of the molten conductor 3 is less than or equal to the length 13 of the insulator 2, which is also clearly shown in Figure 6.

[0080] In further embodiments, particularly when the molten conductor 3 is provided within the insulator 2 in a wound state, the length 12 of the molten conductor 3 may be specified to exceed the length 13 of the insulator 2. In a preferred illustrated embodiment, an elongated molten conductor 3 is provided. This molten conductor 3 may have various forms, for example, it may be formed as a molten conductor ribbon and / or preferably as a molten conductor wire having a circular and / or elliptical cross-section.

[0081] Figure 2 clearly shows that the end region 10 of the molten conductor 2 is completely enclosed by the connecting means 11.

[0082] In further embodiments not shown in detail, the housing 8 may not be completely filled by the connecting means 11 and / or the end region 10 of the molten conductor 2 may not be completely confined by the connecting means 11, and in particular, at least one portion of the end region 10 of the molten conductor 2 may not be confined in such a way that it protrudes beyond or into the connecting means 11.

[0083] The connection means 11 is located exclusively within the area of ​​the housing section 8, as is also shown in Figure 6.

[0084] Although not shown in detail, the through-opening 9 has an opening width 24 of 0.1 mm to 6 mm, preferably 0.5 mm to 5 mm. This opening width 24 is shown, for example, in Figure 6. Particularly preferable, the opening width 24 is 1.1 to 1.5 mm.

[0085] Figure 7 shows that the housing section 8 is formed as a V-shaped recess and a frustoconical recess. In particular, the opening angle α, which corresponds to twice the angle between the generatrix of the frustoconical and the cone axis, as shown in Figure 9, may be 20° to 90°, and especially 50° to 70°.

[0086] The frustoconical recess is characterized by having both end faces (bottom and top (also called the cross-section)) open, and its circumferential surface being formed as a leg protruding from the bridging region 20.

[0087] Figure 3 shows that the connecting means 11 located within the housing 8 is in direct contact with the inner wall 14 of the outer cap 6 that faces the interior 7 of the insulator 2, and in particular, with the inner wall 14 that rests on the open end face of the insulator 2.

[0088] Figure 3 shows that the housing 8 is filled at least substantially completely with the connecting means 11.

[0089] Although not shown in the figures, in further embodiments, the housing 8 may be only partially filled by the connecting means 11. The connecting means 11 is particularly integrally formed. The connecting means 11 fills at least 20%, and particularly at least 40%, of the volume of the housing 8.

[0090] The outer cap 6 may be connected to the auxiliary cap 4, for example, by press fitting and / or crimp connections. In particular, the outer cap 6 is connected to the auxiliary cap 4 via at least one crimp connection, and in particular at least four crimp connections.

[0091] Figure 4 shows that the auxiliary cap 4 has a circumferential surface 15 that surrounds the wall of the insulator 2. The circumferential surface 15 of the auxiliary cap 4 may be connected to the wall of the insulator 2 by friction, which is also evident from Figure 5. Furthermore, Figure 4 shows that the circumferential surface 15 has at least one locking leg portion 16 that protrudes at the end and preferably extends around the entire circumference.

[0092] As is clear from Figure 3, the locking leg portion 16 may be engaged with the back side of the outer cap 6.

[0093] Figure 2 shows that the outer cap 6 is configured to completely cover the end face 5 of the insulator 2. In this case, the outer cap 6 has an outer peripheral surface 17, as shown in Figure 1. This outer peripheral surface 17 may be in contact with the wall of the insulator 2 at least indirectly, or it may surround the wall of the insulator 2 at least indirectly. In the embodiment shown in Figure 3, the peripheral surface 15 of the auxiliary cap 4 is positioned between the wall of the insulator 2 and the outer peripheral surface 17. Preferably, the outer peripheral surface 17 may be connected to the peripheral surface 15 of the auxiliary cap 4 by friction, or it may be connected to the wall of the insulator 2 at least indirectly by friction.

[0094] The connecting means 11 used in the illustrated embodiment may have solder as its material and / or be made of solder. Although not shown in the illustration, the connecting means 11 may also be a conductive adhesive, particularly a silver conductive adhesive.

[0095] Furthermore, although not shown in the figures, the connecting means 11 may be formed by a covering for the molten conductor 3, particularly a covering provided on the end region 10 of the molten conductor 3. This covering may be formed as a tin covering in particular.

[0096] The connecting means 11 may be formed in the form of a wire, as a solder paste, as a pellet, or as a molded member before melting. When solder is used as the connecting means 11, it is particularly preferable that the solder material is lead-free.

[0097] Figure 7 shows that the auxiliary cap 4 has a bridging region 20 connecting its circumferential surface 15 to the housing 8. The bridging region 20 may further be followed by the circumferential surface of the housing 8, particularly the circumferential surface of the frustoconical recess. The bridging region 20 may further define a further opening 21. In this case, this further opening 21 may be located opposite the through opening. In this case, the further opening 21 and the through opening 9 may form a recess or the end face of the housing 8. The bridging region 20 may rest at least partially on the end face 5 of the wall of the insulator 2, as shown in Figure 3. The bridging region 20 may further protrude beyond the wall of the insulator 2, in particular, in this case the bridging region 20 protrudes so as to extend around the entire circumference of the wall of the insulator 2.

[0098] The further opening 21 may be formed in a shape that is at least substantially circular, as shown in Figure 7. The area of ​​the further opening 21 may be 50% to 80% of the area of ​​the open end face 5 of the insulator 2.

[0099] Although not shown in detail in the diagram, the interior 7 of the insulator 2 is at least partially filled with an arc extinguishing agent, particularly arc extinguishing sand.

[0100] Although not shown in detail in the illustrations, the insulator 2 may have ceramics and / or plastic as its material, and / or may be composed of ceramics and / or plastic.

[0101] As explained at the beginning, the diagram shows that in addition to the auxiliary cap 4, there is also a further auxiliary cap 22 covered by a further outer cap 23. This further auxiliary cap 22 and the further outer cap 23 may be formed in accordance with the features described above in relation to the auxiliary cap 4 and the outer cap 6. That is, the further auxiliary cap 22 may also be provided so as to at least partially cover the other end face 5 of the insulator 2. The further outer cap 23 may be electrically connected to the further auxiliary cap 22, and may preferably completely cover this further auxiliary cap 22.

[0102] Figure 10 shows a schematic method flow for manufacturing a fuse 1 formed by one of the embodiments described above. The method includes steps A to H, as shown in Figure 10.

[0103] In step A, an insulator 2, at least one auxiliary cap 4, at least one outer cap 6, and at least one molten conductor 3 are prepared. In the subsequent step B, the auxiliary cap 4 is attached to one end face 5 of the insulator 2.

[0104] Step C may be optionally provided and includes attaching an additional auxiliary cap 22 to the other end face 5 of the insulator 2.

[0105] After step C of the method, step D of the method is carried out. In step D, the molten conductor 3 is introduced into the interior 7 of the insulator 2. The introduction of the molten conductor 3 may be done through the through-opening 9 of the housing portion 8 of the auxiliary cap 4.

[0106] In step E of the method, the auxiliary cap 4 is connected to the molten conductor 3 by arranging the connecting means 11 within the housing portion 8 of the auxiliary cap 4, thereby electrically connecting the auxiliary cap 4 to the molten conductor 3.

[0107] Steps F and G are optional. In step F, after step E is performed, the insulator 2 is rotated particularly by 100° to 200°, preferably about 180°. In the optional step G, the arc extinguishing agent is preferably introduced through a further housing 8 of the uncovered end face 5 and / or further auxiliary cap 22, which is not yet filled by the connecting means 11. The arc extinguishing agent may be located inside 7 of the insulator 2.

[0108] In step H of the method, the auxiliary cap 4 is covered by the outer cap 6 for electrical contact.

[0109] Although not shown in the figures, preferably after step F and / or after step G and / or H, the connecting means 11 is placed in the further housing 8 of the further auxiliary cap 22, thereby connecting the further auxiliary cap 22 to the molten conductor 3, thereby electrically connecting the further auxiliary cap 22 to the molten conductor 3, in particular, in this case the further auxiliary cap 22 is covered by the further outer cap 23 for electrical contact.

[0110] Furthermore, although not shown in the figures, the connecting means 11 may be heated after being placed in the housing 8. Heating may be carried out in particular by melting the connecting means 11. Such a heating step may be carried out in particular by flame, resistance brazing, laser brazing, hot air and / or induction. Alternatively or additionally, the connecting means 11 may be specified to be formed in the form of a wire, as solder paste, as pellets and as molded members before heating and / or melting. Finally, the connecting means 11 may be provided in a variety of forms, and a lasting connection with the end region 10 of the molten conductor 3 can be achieved by melting or liquefying the connecting means 11. [Explanation of Symbols]

[0111] 1 Fuse 2 Insulator 3. Molten conductor 4. Auxiliary cap 5 2 end face 6. Outer cap 7 2 inside 8 4 storage compartments 9 Through-opening 10 3 edge region 11 Connection means Length 12 3 13 2 length 14 6 interior wall 15 4 circumferential surface 16 Locking leg 17 Outer surface 18 10 length 19 8 depth 20 Bridging Areas 21 Further opening 22. Additional auxiliary caps 23. Further outer cap 24 Opening width α Opening angle

Claims

1. A fuse (1), particularly an SMD fuse, comprising: an insulator (2) open at the end face; at least one molten conductor (3) disposed within the insulator (2); at least one auxiliary cap (4) electrically contacted to the molten conductor (3) for at least partially covering the end face (5) of the insulator (2); and an outer cap (6) assigned to the auxiliary cap (4) for at least partially, preferably completely covering the auxiliary cap (4) and electrically contacted to the auxiliary cap (4), The auxiliary cap (4) has a housing portion (8) that protrudes into the interior (7) of the insulator (2), and the housing portion (8) has a through-opening (9) that protrudes into the interior (7) of the insulator (2), and the end region (10) of the molten conductor (3) is guided through the through-opening (9). The end region (10) of the molten conductor (3) is electrically connected to the auxiliary cap (4) by material connection via a particularly lead-free connecting means (11) located within the housing (8). The outer cap (6) covers the auxiliary cap (4) such that the connecting means (11) is captured and / or encapsulated between the auxiliary cap (4) and the outer cap (6). A fuse (1) characterized by the following features.

2. The molten conductor (3) terminates within the housing portion (8) inside the insulator (2) and / or is positioned without contact with the outer cap (6) and / or the auxiliary cap (4), and / or The length (12) of the molten conductor (3) is less than or equal to the length (13) of the insulator (2), and / or The end region (10) of the molten conductor (2) is completely enclosed by the connecting means (11). The fuse according to claim 1, characterized in that...

3. The fuse according to claim 1 or 2, characterized in that the connecting means (11) is located exclusively in the area of ​​the housing portion (8), and / or the through-opening (9) has an opening width (24) of 0.1 mm to 6 mm, preferably 0.5 mm to 5 mm, more preferably 0.8 mm to 2.4 mm, and particularly 1.1 mm to 1.5 mm.

4. The fuse according to any one of claims 1 to 3, wherein the housing portion (8) is formed as a V-shaped recess and / or a frustoconical recess, and in particular, the opening angle (α) of the housing portion (8) formed as a frustoconical recess is 10° to 100°, preferably 20° to 90°, and more preferably 50° to 70°.

5. The fuse according to any one of claims 1 to 4, characterized in that the connecting means (11) located within the housing (8) is in direct contact with the inner wall (14) of the outer cap (6) that faces the interior (7) of the insulator (2).

6. The fuse according to any one of claims 1 to 5, characterized in that the housing (8) is at least substantially completely filled with the connecting means (11), or at least 20%, preferably at least 30%, and more preferably at least 40% of the volume of the housing (8) is filled with the connecting means (11), in particular solder.

7. The fuse according to any one of claims 1 to 6, characterized in that the outer cap (6) is connected to the auxiliary cap (4) via a press fit, and / or the outer cap (6) is connected to the auxiliary cap (4) via at least one crimp connection, in particular at least four crimp connections.

8. The auxiliary cap (4) has a circumferential surface (15) surrounding the wall of the insulator (2), and in particular, the circumferential surface (15) of the auxiliary cap (4) is frictionally connected to the wall of the insulator (2), and / or in particular, the circumferential surface (15) has at least one locking leg (16) protruding from the end and preferably extending around the entire circumference, the locking leg (16) engaging with the back side of the outer cap (6), and / or The outer cap (6) is configured to completely cover the end face (5) of the insulator (2), and preferably has an outer peripheral surface (17) which at least indirectly surrounds the wall of the insulator (2), and preferably is frictionally connected to the peripheral surface (15) of the auxiliary cap (4) and at least indirectly frictionally connected to the wall of the insulator (2). A fuse according to any one of claims 1 to 7, characterized in that

9. The connecting means (11) has and / or a conductive adhesive, particularly a silver conductive adhesive, as a material, or is made of solder and / or a conductive adhesive, particularly a silver conductive adhesive, or the connecting means (11) is formed as a conductive coating, preferably a tin coating, surrounding the end region (10) of the molten conductor (3), and / or The connecting means (11), preferably the solder, is formed in the form of a wire, as a solder paste, as a pellet, or as a molded member before melting, and / or the connecting means (11), preferably the solder, is lead-free. A fuse according to any one of claims 1 to 8, characterized in that

10. The fuse according to any one of claims 1 to 9, wherein the auxiliary cap (4) has a bridging region (20) that connects its circumferential surface (15) to the housing (8), and in particular the bridging region (20) is at least partially resting on the end face (5) of the wall of the insulator (2), and preferably protruding in particular from the end face (5), and / or in particular the bridging region (20) protruding so as to extend around the entire circumference of the wall of the insulator (2).

11. The fuse according to any one of claims 1 to 10, wherein the housing portion (8) has a further opening (21) preferably formed at least substantially circularly, facing the through opening (9) protruding into the interior (7) of the insulator (2), and in particular, the area of ​​the further opening (21) is 30% to 90%, preferably 50% to 80%, and more preferably 60% to 75% of the area of ​​the open end face (5) of the insulator (2).

12. The interior (7) of the insulator (2) is at least partially filled with an arc extinguishing agent, particularly arc extinguishing sand, and / or The insulator (2) has and / or is made of ceramics and / or plastic as its material. A fuse according to any one of claims 1 to 11, characterized in that

13. A fuse according to any one of claims 1 to 12, characterized in that it is provided with a further auxiliary cap (22) for at least partially covering the other end face (5) of the insulator (2) and which is in contact with the molten conductor (3), and a further outer cap (23) assigned to the further auxiliary cap (22) and which at least partially, preferably completely covers the further auxiliary cap (22) and is electrically in contact with the further auxiliary cap (22).

14. A method for manufacturing a fuse (1) according to any one of claims 1 to 13, preferably carried out continuously. A) The step of preparing an insulator (2), at least one auxiliary cap (4), at least one outer cap (6), and at least one molten conductor (3), B) The step of attaching the auxiliary cap (4) to one end face (5) of the insulator (2), C) Optionally, attach an additional auxiliary cap (22) to the other end face (5) of the insulator (2). D) A step of introducing the molten conductor (3) into the interior (7) of the insulator (2), particularly through the through-opening (9) of the housing portion (8) of the auxiliary cap (4), E) The step of connecting the auxiliary cap (4) to the molten conductor (3) by arranging the connecting means (11) in the housing portion (8) of the auxiliary cap (4), thereby electrically connecting the auxiliary cap (4) to the molten conductor (3), F) Optionally, rotate the insulator (2) by a range of 100° to 200°, preferably about 180°. G) Optionally, the step of introducing an arc extinguishing agent, preferably through the uncovered end face (5) and / or the further housing (8) of the further auxiliary cap (22) that is not yet filled by the connecting means (11), H) The step of covering the auxiliary cap (4) with the outer cap (6) for electrical contact. Methods that include...

15. Preferably, after step F) and / or G) and / or H), the method of connecting the further auxiliary cap (22) to the molten conductor (3) by arranging the connecting means (11) in the further housing (8) of the further auxiliary cap (22), thereby electrically connecting the further auxiliary cap (22) to the molten conductor (3), and / or covering the further auxiliary cap (22) with a further outer cap (23) for electrical contact, as described in claim 14.

16. The method according to claim 14 or 15, characterized in that, after placing the connecting means (11) in the housing (8), it is heated, in particular by flame, resistance brazing, laser brazing, hot air and / or induction, and in particular melted, and / or the connecting means (11), preferably solder, is formed in the shape of a wire, as solder paste, as pellets or as a molded member before heating and / or melting.

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