EP2003673B1 - Miniature fuse and method of fabrication therefor - Google Patents

Description

Field of the invention

The invention relates to a compact fuse, in particular for use in automobiles, with an electrically conductive contact element and a housing made of electrically insulating material, wherein the contact element comprises two spaced-apart contact regions and a melting region arranged between the contact regions. Furthermore, the invention comprises a method for producing such a compact fuse.

State of the art

Fuses are used in many areas of technology, for example in vehicle construction. Depending on the respective field of application, exactly predetermined and standardized connection geometries must be observed. In addition to the connection geometries, however, the fuses must also be designed and designed to meet the technical specifications with regard to the nominal current and the tripping characteristics. Other conditions to be met depend on the specific field of application of the fuse and the feeds suitable for this area.

The fuses used in the vehicle sector are those skilled in the art, for example, under the terms "Flachstecksicherungen", "Schraubsicherung SF" or "Multifuse", i. integrated in Einstandsgitter one piece, known.

From the EP 1 336 978 A1 In addition, a so-called low-profile fuse is known, in which a contact element is arranged in a housing made of electrically insulating material, which comprises two spaced-apart contact regions and a melting region arranged between the contact regions. To fix the contact element in the housing, the housing is closed after insertion of the contact element. The GB 2 090 081 A represents the closest prior art, but does not disclose a contact element comprising two contact areas and a melting area arranged therebetween, consists of a sheet material and is arranged in a double-layered manner in the region of the contact areas.

Presentation of the invention

The invention has the object to provide a generic compact fuse and a method for producing such a compact fuse that allow easy mass production.

This object is achieved by a compact fuse with the features of claim 1 and a method for producing such a compact fuse with the features of claim 11. Advantageous embodiments follow from the remaining claims.

The compact fuse according to the invention comprises an electrically conductive contact element and a housing made of electrically insulating material, wherein the contact element has two spaced-apart contact areas and one between comprises the contact areas arranged melting area. The contact areas have positioning areas that engage in a form-fitting manner in corresponding receiving geometries in the housing. The contact element consists of a sheet material, which is arranged in two layers in the region of the contact areas. The positioning areas provide a very simple way to position and fix the contact element in the housing. The advantage of this embodiment is that the provision of the housing and the punching and shaping of the contact element can be carried out in independent production areas and the insertion of the contact element in the housing can be carried out in a single step within the manufacturing process. The design of the contact element with contact areas and melting area of a flat material makes it very easy to realize the desired cross sections for the contact areas as well as the melting area. Since in the melting region, depending on the desired release behavior, in some cases a very small cross-sectional area must be provided, this can also be achieved by adjusting the web width of the melting region, but care must also be taken that very narrow webs are more vulnerable to damage and, in addition, the Material thickness of a strip material can be set with lower tolerances than complex, punched-out geometries. For these reasons, the double-layered forming of the contact regions, but the only single-layered shaping of the melting region is particularly preferred.

According to a preferred embodiment of the invention, the contact areas are substantially rectangular, the mutually remote first longitudinal sides of the contacting serve in a fuse holder. This is a simple design, which is particularly advantageous in view of the possibility described later, the contact areas double-layered, is advantageous.

Preferably, the compact fuse further includes test lugs each on a voltage applied to the first longitudinal side of the contact areas, which extend through passages in the housing. Defining the longitudinal sides of the rectangular contact areas, the Prüfansätze are each provided on a transverse side. By extending the Prüfansätze through openings in the housing, can be achieved in the process step of inserting the contact element into the housing in a simple way an additional fixation of the contact element in the housing, but also ensure the correct positioning of the contact element in the housing.

Preferably, the Prüfansätze each consist of two layers of material, which are braced against each other for positive locking in the housing element. In this way, an additional fixation of the contact element in the housing can be achieved, wherein to avoid an additional process step in the production of a compact fuse Prüfansätze can be shaped so that they are moved elastically to each other when pushed through the opening in the region of the housing and after Passage through the opening in the housing can spring back to their original position in which they fulfill the function of additional fixation of the contact element in the housing.

The positioning lugs are preferably arranged in each case on the mutually facing, second longitudinal sides of the contact regions and project at an angle out of the plane of the contact element. The term "plane" must not be interpreted too narrowly in the present case, since the possibility of forming the contact areas in two layers and the possibility described above of designing the double-layered test approaches and bracing them against one another, the contact element originally punched out of a strip material is no longer complete in a common Level is arranged. The term "plane" is therefore intended to refer to the planar arrangement of the contact element as such, whereas the positioning approaches project at an angle from this plane and are preferably bent at an angle of 90 °.

According to a preferred embodiment, the compact fuse further has a protective web on at least one contact region of the contact element, which extends in the direction of the other contact region, without touching it. Since the prefabricated contact elements are bulk materials which are stored in storage containers and fed to the assembly, the protective webs on the contact elements have the function of protecting the melting region and preventing excessive binding of the contact elements with one another. However, the essential function of the guard bar or guard bars is to protect the melting area in the mounted state of the compact fuse. For this reason, it is not mandatory that the protective web or the protective webs must be located on the contact element. In the same way it is also possible to design a protective web on the housing, which at least reduces the risk that objects can penetrate into the housing and into the region of the melting region and damage the melting region.

According to a further preferred embodiment of the invention, the melting region is designed such that its length is increased between the contact regions which are locally predetermined due to the connection geometry. This can be done in particular by the melting area does not represent a straight connection between the contact areas, but has a curved shape or consists of longitudinally adjacent sections, which are arranged at an angle to each other. Such geometries are particularly preferred in the form of an S-shape, V-shape, or W shape. Another advantage of angularly arranged sections is that they can more easily compensate for thermal expansion between the contact areas than a straight connection between the contact areas.

Preferably, the contact element consists of zinc, which is optionally coated with tin, a tin alloy or silver. This coating serves to protect the contact element.

Preferably, the housing is integral with a front-side front element and a subsequent to the front element first housing portion and a second housing portion. The one-piece production of the housing eliminates the step of connecting individual housing parts, which is advantageous in terms of the task of the simplest possible mass production.

The inventive method comprises the steps of providing the housing, preferably by injection molding, the punching of the contact element of an optionally coated strip material, the bending of the positioning, so that they can positively engage in the receiving geometries in the housing, and the insertion of the preformed contact element in the housing , In addition, after the step of punching out the contact element from a strip material, the contact element is folded such that the material is placed over the other in the area of the contact areas in a double-layered manner.

According to a preferred embodiment, the method further comprises the step of bending the test lugs extending through openings in the housing. This can be done before inserting the contact areas in the housing by the contact geometry between Prüfansätzen and the passage opening in the housing are designed so that the Prüfansatz or the Prüfansätze when inserted into the Resilient deform housing and spring back elastically after passing through the opening in the housing. Alternatively, it is also possible to aufzubiegen the Prüfansätze only after insertion of the contact element in the housing. This step can be done simultaneously with the functional test of the compact fuse.

Brief description of the figures

Fig. 1

eine erfindungsgemäße Flachsicherung in gebrauchsfertigem Zustand darstellt;

Fig. 2

einen Schnitt durch die Kompaktsicherung nach Fig. 1 im Bereich der Positionierbereiche zeigt;

Fig. 3

einen Schnitt durch das Gehäuse im Bereich des Frontelements des Gehäuses darstellt;

Fig. 4

eine Ausführungsform eines Kontaktelements in montagefertigem Zustand zeigt;

Fig. 5

eine Aufrissansicht des in Fig. 4 in Draufsicht dargestellten Kontaktelements zeigt;

Fig. 6

das Gehäuse mit eingesetztem Kontaktelement vom stirnseitigen Frontelement her zeigt; und

Fig. 7

den gestanzten Rohling des Kontaktelements nach dem Ausstanzen zeigt.

The invention will be described purely by way of example with reference to the accompanying drawings, in which

Fig. 1

a flat fuse according to the invention in ready-to-use state represents;

Fig. 2

a section through the compact fuse after Fig. 1 in the area of the positioning areas;

Fig. 3

a section through the housing in the region of the front element of the housing represents;

Fig. 4

shows an embodiment of a contact element in ready to install state;

Fig. 5

an elevation view of the in Fig. 4 shows in contact plan illustrated contact element;

Fig. 6

the housing with inserted contact element from the frontal front element forth shows; and

Fig. 7

shows the punched blank of the contact element after punching.

Ways to carry out the invention

In the following figures, the same components are designated by the same reference numerals.

The fuse designated generally by reference numeral 10 will hereinafter be referred to as a compact fuse, although in common usage the term "low profile" fuse is also frequently used. The compact fuse 10 consists of a housing 12, and of an electrically conductive contact element 14. The housing 12 has essentially a front-side front element 16 and an adjoining first housing portion 18 and the second housing portion 20. The first and second housing sections are preferably designed in one piece with the front element 16. Between the first housing portion and the second housing portion is a substantially slot-shaped space into which the contact element 14 is inserted, from that in the illustration Fig. 1 the contact areas 22 and 24 are visible.

The contact areas are as shown in the illustration Fig. 1 can be seen, double-layered configured with a first portion 22a and 24a and second portion 22b and 24b of the contact area, which lie flat over each other. On the side facing away from the front element 16 side, the contact areas 22 and 24 are preferably chamfered, as indicated by reference numeral 26 in Fig. 1 is shown. The chamfer serves to facilitate the insertion of the compact fuse 10 in a corresponding receiving geometry.

The housing shape shown is primarily based on the specification of standardized connection geometries, but in the region of the front element 16 preferably gripping surfaces 28 are provided which facilitate the removal of the compact fuse 10 from a corresponding fuse holder using a special tool.

The compact fuse 10 has positioning receptacles 30, which serve a positioning approach each of the two To record contact areas, as shown in the representation in Fig. 2 it becomes clear that a cut through the in Fig. 1 shown housing 10 in the area indicated by reference numeral 32 positioning areas shows. The positioning regions 32 are in the illustrated embodiment according to Fig. 2 bent-up areas in the second section 22b or 24b of the contact region 22 or 24, in which the material of the contact element is partially bent upwards and extends substantially at an angle of 90 ° upwards. The positioning regions 32 are designed with respect to their dimensions but also position on the positioning receptacles 30 in the second housing section 20. To simplify the assembly, identically shaped positioning receptacles 30 are also located in the first housing section 18, so that attention must not be paid to the correct alignment of the housing 12 in the context of the simplest possible mass production.

In Fig. 2 also visible are protective webs 34, which are formed from the first portion 22a and 24a of the contact area and the viewer facing opening area between the first housing portion 18 and the second housing portion 20 in Fig. 2 close, so that the risk of damaging the in Fig. 1 and 2 not shown melting range between the contact areas 22, 24 is reduced. The geometry and length, as well as the attachment on one or both sides of the protective webs 34 can be freely selected, as long as there is no short-circuit current between the contact regions 22, 24 can come. Alternatively or additionally, it is also possible to attach a protective web to the first housing section 18 or second housing section 20, as long as thereby the insertion of the contact element 14 in the context of assembly is not hindered.

Fig. 3 shows a section through the housing 10 in the region of the slot-shaped receptacle between the first Housing portion 18 and second housing portion 20. The first housing portion 18 has positioning receptacles 30, which, as shown in the Fig. 3 can be seen, do not extend over the entire length of the first housing portion, but only over that area in which the corresponding bent or upwardly extending positioning portion 32 of a contact element is located. The front element 16 has through openings 36, which, as will be described later, serve for the passage of test lugs on the contact element. As well as from the representation in Fig. 6 it can be seen, the passage openings 36 are provided with chamfers 38, so that the openings 36 extend to the outside of the compact fuse. Furthermore, in Fig. 3 illustrated that the first housing portion 18 has a positioning edge 40, which also serves for the correct insertion of the contact element 14 in the housing 10.

Fig. 4 shows an embodiment of a contact element 14 consisting of the contact regions 22, 24 and a melting region 42. Also in Fig. 4 The contact element 14 further comprises test lugs 44, which are integrally formed with the contact element and located on a transverse side of the substantially rectangular contact areas 22, 24. In the area of the lateral side at which the test approaches are located, there is also a corresponding to that in Fig. 3 formed positioning edge shaped positioning 46 formed.

In Fig. 4 Also shown are the positioning portions 32 which extend from the facing longitudinal sides of the contact portions 22, 24 and, as shown in the side view of FIG Fig. 4 illustrated contact element 14 in Fig. 5 shows are bent at an angle of 90 ° upwards. From the illustration in Fig. 5 It also becomes clear that in the region of the contact regions 22, 24, the material is double-layered, as already based on the Fig. 1 and 2 was apparent. Only the second section 24b or 22b is bent upwards to form a positioning region 32 in each case. The material in the region of the melting region 42 as well as the protective webs 34, however, is formed only a single layer.

The contact element is preferably made of zinc, which may optionally be provided with tin, a tin coating or silver.

Fig. 6 additionally shows a compact fuse in the assembled state of the front element 16 of the housing, wherein the passage openings 36 and their chamfers are visible. Also visible are the test lugs 44, which in the case of the double-layered folding of the material in the region of the contact regions 24, 26 are also configured as double-layered and can be spread apart in order to realize an additional fixation of the contact element in the housing. The spreading apart of the Prüfansätze can be done after assembly, ie the insertion of the contact element in the housing, for example, by simultaneously spreading the Prüfansätze carried out when testing the assembled fuse. Alternatively, it is also possible to bend the Prüfansätze before assembly already apart, but to provide them with a corresponding chamfer, which cooperates with a correspondingly shaped geometry in the region of the passage opening and the Prüfansätze elastically deformed towards each other, so that after passing through the passage opening 36 can spring back automatically.

Alternatively, it is also possible to reduce the material thickness of the Prüfansätze compared to the material thickness of the contact element or provide only a Prüfansatz, so that after the production of a double-layered contact region, the test lug is provided only in one layer.

The production of the contact element of a strip material is made Fig. 7 clear. The raw material shown here is still connected to a carrier 48, which is, however, separated in the further production of the contact element. How out Fig. 7 It can be seen that the individual layers of the contact regions 22a, 22b and 24a, 24b are still present separately from one another. Between the individual areas is the fold line 48, to which in the further production of the respective second sections 22 b and 24 b from the plane of the Fig. 7 be placed up and on the sections 22a and 22b. In a further step, the positioning regions 32 are bent upwards and possibly also the test lugs 44 preformed so that they spread apart automatically after insertion of the contact element into the housing.

Separate from the production of the contact element, the housing is preferably produced by injection molding, so that only the contact elements must be inserted into the housing and, if appropriate, test lugs can be bent to improve the fixation of the contact elements in the housing.

The compact fuse according to the invention and the method for this make a simple and very cost-effective mass production of such components possible.

Claims (12)

1. A compact fuse, in particular for use in automobiles, comprising:

   - an electrically conductive contact element (14); and

   - a housing (12) made of an electrically insulating material, wherein

   - the contact element (14) comprises two mutually spaced contact regions (22, 24) and a fusing region (42) which is arranged between the contact regions,

   wherein the contact regions (22, 24) have positioning regions (32) which engage in a positive fit with correspondingly shaped receiving geometries (30) in the housing (12), characterised in that
   the contact element (14) consists of a planar material which is arranged in two layers (22a, 22b, 24a, 24b) one on top of the other in the region of the contact regions (22, 24).
2. The compact fuse according to Claim 1, characterised in that the contact regions (22, 24) are substantially rectangular, wherein the first longitudinal sides, which face away from each other, are used for contacting in a fuse receptacle.
3. The compact fuse according to Claim 2, further comprising test protrusions (44), each on a side of the contact regions (22, 24) abutting the first longitudinal side, which extend through transit openings (36) in the housing (12).
4. The compact fuse according to Claim 3, characterised in that the test protrusions (44) each consist of two layers of material which are braced against each other in order to lock in place in a positive fit in the housing (12).
5. The compact fuse according to any one of the preceding claims, characterised in that the positioning protrusions (32) are respectively arranged on the mutually facing second longitudinal sides of the contact regions (22, 24) and protrude out of the plane of the contact element (14) at an angle.
6. The compact fuse according to any one of the preceding claims, further comprising a protective projection (34) on at least one contact region (22, 24) of the contact element (14) which extends towards the other contact region without touching it.
7. The compact fuse according to any one of the preceding claims, characterised in that the contact element (14) is punched from a strip material.
8. The compact fuse according to any one of the preceding claims, characterised in that the fusing region (42) is configured such that its length between the spatially predefined contact regions (22, 24) is increased, by exhibiting a curved shape or comprising mutually adjoining portions which are arranged at an angle to each other and particularly preferably exhibit the shape of an S, V or W.
9. The compact fuse according to any one of the preceding claims, characterised in that the contact element (14) consists of zinc and is optionally coated with tin, a tin alloy or silver.
10. The compact fuse according to any one of the preceding claims, characterised in that the housing (12) consists of one piece comprising an end-facing front element (16) and a first housing portion (18) and second housing portion (20) which adjoin the front element.
11. A method for manufacturing a compact fuse according to any one of the preceding claims, comprising the steps of:

    (a) providing the housing, preferably by injection-moulding;

    (b) punching the contact element from a strip material;

    (c) bending the position regions up, in order that they can engage with the receiving geometries in the housing in a positive fit;

    (d) inserting the contact element into the housing,

    wherein after Step (b) or (c), the contact element is folded such that the material in the region of the contact regions is placed in two layers one on top of the other.
12. The method according to Claim 11, further comprising the step of (c2) bending up the test protrusions which extend through an opening in the housing.

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