WO1999036929A1 - Fuse element structure - Google Patents

Abstract

The invention relates to a fuse element structure having a plate-shaped busbar (3) with a large upper and lower surface and with a smaller peripheral surface forming an edge, whereby at least two terminal pieces (1) are respectively connected to the busbar (3) in an electrical and mechanical manner via a fuse element (2). Each fuse element (2) has a smaller cross-section than the busbar (3) and the respective terminal piece (1). The busbar (3), the fuse element (2) and the terminal piece (1) are formed out of a metal plate. In order to permit the use of lower quantities of material with improved properties, especially pertaining to the busbar, the invention provides that at least two fuse elements (2) are arranged at an angle so that they are adjacent to one another and/or to the busbar (3).

Description

 Fusible conductor structure

The invention relates to a fusible link structure with a plate-shaped busbar with a larger upper and lower surface and a smaller edge-shaped peripheral surface, at least two connecting pieces being electrically and mechanically connected to the busbar via a fusible link, each fusible link having a smaller cross section than the busbar and that respective connector and both the busbar and fuse element and connector are formed from a metal plate.

A fuse element structure similar to the aforementioned type has already been proposed as additional cut-off point fuses in motor vehicles which are arranged between the vehicle battery and the conventional fuses for smaller consumers. Such base fuses serve as backup fuses for several parallel circuits and switch off selectively to the downstream fuses. The bus bar is formed in common with a plurality of fusible conductors and connectors attached thereto from a metal plate by punching, and there are both the busbar and the fusible conductor and the Anschlußstύ ^'blocks more or less in a single plane. The fusible conductors are produced by narrowing their cross-section compared to the cross-section of the connecting pieces on the one hand and of course the busbar on the other. The thickness of such a metal plate can have dimensions in the range from 0.05 mm to 3 mm.

The busbar of the older fuse element structure with the features described at the outset is designed in the shape of a rail so that the entire fuse element structure has an elongated shape Busbar arranged outgoing. The latter are essentially straight and are parallel to each other. Due to this long design, the electrical current from the middle connection device over a longer path to the outer fusible conductors and connectors must be carried out with the result that the elongated busbar is heated to the end area or better said exposed to a not inconsiderable thermal load Undesirable heating of the busbar leads, among other things, to its expansion and thus also mechanically stresses the outgoing fuse element. If one wanted to counteract this thermal stress in the older fuse element structure, this could be done to provide a larger cross section. Unfortunately, this means a greater use of materials.

The object of the invention is therefore to design a fusible conductor structure of the type mentioned at the outset in such a way that less material is required with improved properties, in particular of the busbar. Certainly, the technical advantages already achieved with the older fuse element structure should not be sacrificed, and the improvement mentioned relates, among other things, to mechanical properties, such as stability, for example.

The object is achieved according to the invention in the fusible conductor structure described at the outset in that at least two fusible conductors are arranged at an angle to one another and / or to the busbar. Assuming turn of plate-like metal, cited in certain embodiments, for example sheet metal, for the manufacture of the fusible conductor structure, then the height of the edge-shaped Umfangsflä ^'che approximately equal to the plate thickness, for example 2 mm. Is visible - even measured over the entire circumference of the busbar - the kantenfό ^'-shaped circumferential äche smaller than the upper and / or lower surface of the bus bar that are parallel to each other. In the sense of this relation between surface and / or lower surface on the one hand and the edge-shaped peripheral surface on the other hand, the explanations "larger" or "smaller" are to be understood. The fusible conductors can be attached to the busbar by soldering, welding, cutting tools or punching. The angular arrangement according to the above teaching means in the one case that at least one fuse element is arranged at an angle to at least one other; and in the other case that at least two fusible conductors are arranged at an angle to the busbar. The simplest case is a busbar in the form of a flat plate, and it is easy to imagine how an elongated fusible conductor is set at an angle from the plane of this busbar, for example bent. Another simple special case is that the fuse element is straight, and it is also easy to imagine in this example that one fuse element is positioned at an angle relative to the other. For the last valid case, an example is described below in which such an angle is 45 ° and / or 90 °.

The busbar can also be curved, and even the fusible conductor can be curved. To consider the above teaching of arranging the parts at an angle to one another, mean values, tangents or the position of a certain edge section can be measured. The angular arrangement according to the teaching according to the invention means that not all fuse elements go off at one point or on one edge of the busbar or on one side of the busbar and certainly not in the manner of the previously designed fuse element structure, in which the differently long paths criticized above for the guided one Electricity is inevitable. Rather, the teaching according to the invention advantageously ensures that the current flowing from the connection device through the busbar to the individual fusible conductors with connecting pieces takes approximately the same paths, with the result of a more uniform heating of the busbar, which can thus be kept very low. The material used for the new busbar is less, and yet a temperature gradient comparable to the old structure does not arise within the busbar. The metal used in the busbar is therefore better used.

It is also expedient if, according to the invention, the busbar and the fusible conductor lie in one plane. The simplest embodiment of the new fusible conductor structure is that in which a plate or disk arranged in the middle of the entire structure is surrounded by fusible conductors which extend radially outward in different directions. In the case of four fusible conductors with corresponding connecting pieces, an angle of 90 ° can be enclosed between two adjacent fusible conductors. If one looks at two fusible conductors lying opposite one another, the angle enclosed between them is 180 °. Such a fusible conductor structure can be easily produced by stamping a metal plate and has a mechanically much more stable busbar than is the case with the strip-shaped busbar of earlier, known embodiments.

However, it is also advantageous if, according to the invention, the busbar and the fuse element and the connecting pieces lie in one plane. While in the above-explained embodiments, the Anschlußstü ^'bridge at the radially outer end of the fusible conductor from the general main plane may also be angled, the more easily manufacturable embodiment is as last described, in which the ^{Anschlußstü'} blocks also lie in the same main plane.

A further advantageous embodiment is characterized according to the invention in that at least one fusible conductor, which is preferably of straight design, is attached to the busbar at an angle approximately perpendicular to the plane of the busbar. In motor vehicles in particular, sockets are often arranged in such a way that a fuse element located on a connecting piece could be inserted, the side of which opposite the socket has the busbar, to which supply or discharge lines can be attached. Taking this teaching into account, you can design the fuse element as a connector because such a structure has replaced the two dimensions by the three dimensions of the space. It can be seen that a busbar constructed in this way can be made more compact and also mechanically stable

It is advantageous if, according to the invention, the busbar is polygonal in plan view. The plate forming the busbar can be quadrangular, octagonal or polygonal in plan view of the surface or bottom surface. The four corners of such a board can also be rounded on the outside, because it is the outermost ones Key points, unless a fuse element is connected there, are not necessary for the current flow. This saves additional material.

Another advantageous embodiment is characterized according to the invention in that the busbar is round. A preferred embodiment has a busbar in the form of a circular plate, from which preferably fusible conductors with radially externally attached connecting pieces protrude in a star shape from the periphery, but it is also conceivable that the top view of the busbar has the shape of a quadrant or a beveled quadrilateral such that at least one fusible link leaves each of, for example, two of the four circumferential straight lines - or in another embodiment three of the five circumferential straight lines - a similar embodiment is described below of the drawings still described

The thermal load on the busbar and thus also the thermal load on the fuse element leaving the busbar can be further reduced in that, according to the invention, a connection device is arranged in the busbar in such a way that its distance from the attachment points of the fuse element is essentially the same. What is meant is the distance of the respective fusible conductor to the connecting device If the connecting device is placed in the center with a square or symmetrical polygonal or round, preferably circular busbar in plan view, then the distance to the individual fusible conductors is evidently the same size if the fusible conductor is radial from the center go outwards The flow of the electrical current then takes place radially outwards from the center of the busbar evenly for all fusible conductors, with the result of an optimal utilization of the material of the busbar Cross-section and with an optimal heat dissipation, which is led, for example, radially inwards from the fusible conductor to the connection device. For example, a feed cable can be attached to the connection device and also ensure heat dissipation s, ie act like a heat sink The invention is also advantageously designed in that the connection device is arranged in the middle of the busbar. This embodiment applies to practically all symmetrical busbars, so that the heat dissipation is carried out as cheaply as possible. The heat flow is independent of whether the fusible conductors with the connecting pieces attached to them extend radially outwards in the same plane as the busbar or whether they are angled to a plug shape.In any case, the mechanical expansion of the busbar is due to the controlled or less heating in the Compared to the known or older fusible link structures less

As with the older structures, the current flow in the fuse element structure according to the invention generally takes place from the busbar via the fuse element to the connector. This current flow has different cross-sections in the three parts mentioned, the cross-section in the busbar and also in the connecting piece being larger than in the fuse element. In this case, fuse elements of the same or different characteristics and / or nominal current strength with outgoing-side connecting pieces can be provided

The new fuse element construction is simplified compared to the older solutions, requires lower material costs and allows a compact and weight-saving design.

The characteristic can be adjusted via the number of fusible conductors connected in parallel or via the fusible conductor cross-section, and additional bottlenecks can also be achieved in the respective fusible conductor by embossing, perforation, edge notching or combinations thereof.For example, a reaction solder can be applied to the Influence fusible conductor on its characteristics It is possible to use fusible conductors which have been manufactured separately and which can be manufactured from a material which differs from that of the busbar or the connecting piece. For example, the fuse element for small nominal currents and inertial characteristics can be made of zinc, or for large nominal currents and quick characteristics can be made of silver, while the busbar and the connection pieces consist of copper. You can also use material combinations, as was suggested for the older fuse element structures

Further advantages, features and possible applications of the present invention result from the following description of preferred exemplary embodiments in conjunction with the accompanying drawings. FIG. 1 shows the top view of a first embodiment of a fusible conductor structure with a square busbar in plan view, FIG. 2 shows a second embodiment similar to that of Figure 1, however, the four Corners of the square are just cut off to form an octagonal busbar,

FIG. 3 shows a further different embodiment similar to FIGS. 1 and 2, but instead of a square or octagonal plate, a square plate with rounded corners is used as the busbar.

FIG. 4 shows a fourth embodiment similar to that of the preceding figures, the busbar having the shape of a circular disk,

FIG. 5 shows a fifth embodiment with a busbar in the form of a quadrant, cut out of the circular disk of the busbar according to the embodiment in FIG. 4,

FIG. 6 shows a sixth embodiment of the fusible conductor structure according to the invention with a busbar designed similarly to that of FIG. 5, but designed as a pentagon,

FIG. 7 shows a seventh embodiment of the fuse element structure with a rectangular one

Busbar, from the opposite longer side edges of which parallel fusible conductors,

8a, 8b and 8c show an eighth three-dimensional embodiment, FIG. 8a showing the top view of the intermediate product similar to FIG. 1, FIG. 8b the top view after the fuse element has been bent through 90 ° out of the plane of the busbar, and FIG. 8c the side view of the three-dimensional one Fusible conductor structure, if one looks for example at the structure of Figure 8b from right to left, and

Figures 9a, 9b and 9c similar views as in Figures 8a - 8c, but of another embodiment, the intermediate structure of Figure 9a is similar to the seventh embodiment of Figure 7. FIG. 9c is the side view of the three-dimensional fuse element structure of FIG. 9b when looking upwards from FIG. 9b.

In the figures, the same parts are described with the same reference numbers. Each embodiment of the fusible conductor structure has a plate-shaped busbar 3, the surface of which can be seen with the exception of FIGS. 8c and 9c. The edge-shaped peripheral surface is denoted by 7 in these FIGS. 8c and 9c, and only a portion of the same can be seen, for example in FIG. 8c a quarter of the entire edge-shaped peripheral surface 7. As can be seen, this peripheral surface 7 is smaller than the surface of the busbar 3. Three , four or eight fusible conductors 2 go from the edge-shaped Circumferential surface 7 of the busbar 3 laterally and are each connected radially on the outside to a connector 1.

Figure 1 shows a plan view of the fuse element structure, which extends in a single plane. In the center of the square busbar 3, a mounting hole is shown as a connection device 4. Through this you can insert a screw with a correspondingly larger screw head and clamp it with the eye of a cable lug, so that this cable represents the feed line. The current then flows through the busbar 3 radially to the respective fusible conductor 2, the cross section of which is smaller than the cross section of the radially outer connector 1 and, of course, is also smaller than the cross section of the busbar 3 due to the corresponding punch shape. Also in the connector 1 there is a hole 5 for a screw connection or the like. If in this, as in most of the other embodiments, the current is fed in via the centrally arranged connection device 4, then the further current flow takes place in a star shape via the four fusible conductors 2, each arranged at an angle of 90 ° to one another, to the connection pieces 1.

The embodiments according to FIGS. 2 and 3 also work with the same function, the busbar 3 being designed octagonal there or in FIG. 3 with rounded corners.

In the embodiments of FIGS. 4-6, the fusible conductors 2 are only shown as connecting lines between the busbar 3 and the connecting pieces 1, but instead of the lines, contours similar to those of the fusible conductors 2 of the other embodiments can be thought of.

While in the embodiments according to FIGS. 1-7, no angle is included between the busbar on the one hand and the respective fusible conductor on the other hand, the angles α and β can be seen between adjacent fusible conductors 2. In FIGS. 1-4, the angle between two adjacent fusible conductors is designated with a, in FIGS. 5 and 6 with /?, And in FIG. 7 only opposite fusible conductors are set at an angle to each other at an angle a = 180 °. In the three-dimensional embodiment according to FIGS. 8b, 8c and 9b and 9c, the angle between the flat busbar 3 on the one hand and the bent leg of the straight fuse element 2 on the other hand is denoted by y and is 90 °.

Due to the central arrangement of the connection device 4 with respect to the radially outer fuse element 2, the respective distance between them is the same. In the embodiments of FIGS. 5 and 6, the distance is also the same, but the connection device 4 is located in a corner of the quadrant or pentagon, so that the embodiment is again achieved with the same distance. In the embodiment of FIGS. 7 and 9, the connection device 4 is also arranged in the middle, but the distances to the fusible conductors 2 or their attachment points 6 are somewhat unequal. If, in this embodiment, heating occurs in the area of the centrally arranged connecting device 4, then washers or perforated intermediate plates can be clamped to the connecting device 4 and a material accumulation in the central area of the connecting device 4 can be created by pressure contact. By arranging additional disks or plates, more material is used, but it is optimally used again, because it is only provided where a larger cross section is required for the busbar 3.

The fusible conductors 2 are shown in the embodiments shown here to be essentially straight. The teaching of the invention also applies to curved or arched fusible conductors and busbars.

The fusible conductor structures according to FIGS. 8c and 9c are, so to speak, three-dimensional, because compared to the embodiment of FIGS. 2 or 7, where the busbar 3, the fusible conductor 2 and the connecting pieces 1 lie in one and the same plane, are in the embodiments according to FIGS. 8c and 9c the fusible conductor 2 is bent or bent like a leg by 90 ° out of the plane of the busbar 3. This results in the form of a plug, wherein the Anschlußstü shown below ^'cke 1 represent the plug contacts for a non-illustrated receptacle.

The angle a between adjacent fusible conductors 2 in the embodiments of the figures

1 - 4 is 90 °. In the embodiments according to FIGS. 5 and 6, the comparable angle β = 45 °. But you can also choose a different number of fusible conductors

2 connected to the edge-shaped peripheral surface 7, in which case the respective angle α or β becomes correspondingly smaller.

Claims

 P a t e n t a n s r u c h e Fusible conductor structure with a plate-shaped busbar (3) with a larger top and bottom surface and a smaller edge-shaped peripheral surface (7), at least two connecting pieces (1) being electrically and mechanically connected to the busbar (3) via a fusible conductor (2), each fuse element (2) has a smaller cross-section than the busbar (3) and the respective connector (1), and both the busbar (3) and the fuse element (2) and connector (1) are formed from a metal plate, characterized in that the at least two fusible conductors (2) are arranged at an angle to one another and / or to the busbar (3) Fusible conductor structure according to Claim 1, characterized in that the busbar (3) and the fusible conductor (2) lie in one plane Fusible conductor structure according to Claim 1 or 2, characterized in that the busbar (3) and the fusible conductor (2) and the connecting pieces (1) lie in one plane Fusible conductor structure according to one of Claims 1 to 3, characterized in that at least one fusible conductor (2), which is preferably of straight design, is attached to the busbar (3) at an angle approximately perpendicular to the plane of the latter Fusible conductor structure according to one of claims 1 to 4, characterized in that the busbar (3) is polygonal in plan view Fusible conductor structure according to one of Claims 1 to 4, characterized in that the busbar (3) is round in plan view Fusible conductor structure according to one of Claims 1 to 6, characterized in that a connecting device (4) is arranged in the busbar (3) in such a way that its distance from the attachment points (6) of the fusible conductor (2) is essentially the same Fusible conductor structure according to one of Claims 1 to 7, characterized in that the connecting device (4) is arranged in the middle of the busbar (3)