WO2017021311A1

WO2017021311A1 - Laser cut connector for plate-shaped busbar

Info

Publication number: WO2017021311A1
Application number: PCT/EP2016/068185
Authority: WO
Inventors: Martin REGER
Original assignee: Rogers Germany Gmbh
Priority date: 2015-07-31
Filing date: 2016-07-29
Publication date: 2017-02-09
Also published as: DE202015104023U1

Abstract

A busbar is described, having at least one base body (1) which is plate-shaped in some sections, with a top (1.1) and a bottom (1.2), comprising a conductor layer (2, 2a) and at least one first and second insulation layer (3, 4), connected to the conductor layer (2, 2a), and with a plurality of connectors (5, 5', 5''), wherein at least one connector (5, 5', 5'') comprises at least one connection area (6) and a through-passage opening (7), positioned centrally in the connection area (6) and extending along a central axis MA, and wherein in the connection area (6) the first and second insulation layer (3, 4) are removed over some of the surface area, in which the connection area (6) is segmented into a plurality of connection segments (6a, 6b, 6c, 6d, 6e, 6f,) separated from each other by means of slots (9a, 9b, 9c, 9, 9',) which extend in a star shape with respect to the central axis MA and which are convex at least at the free ends. The connection segments (6a, 6b, 6c, 6d, 6e, 6f) are produced by introduction of the slots (9a, 9b, 9c) into the connection area (6) by means of laser radiation and by a deformation of the connection area (6) along the central axis MA.

Description

LASER CUT CONNECTOR FOR PLATE-SHAPED BUSBAR

The invention relates to a busbar. The structure and operation of such busbars is reasonably well known.

Such busbars are used in different technical sectors for the transmission and distribution of electrical power and/or electrical signals within technical systems, for example in the area of electrical mobility, wind power or transport technology. To achieve this these essentially have a plate-shaped base body comprising multiple layers, specifically at least a first and second insulation layer and an intermediate conductor layer, preferably a metallic layer, for transmitting electrical energy, in particular electric current or electrical signals via the conductor layer. Such multilayer busbars preferably have at least two conductor layers that are insulated from each other and also from the outside by means of multiple layers of insulation.

To produce a mechanical, electrically conductive connection, busbars comprise at least one connector, preferably a plurality of connectors, on each of which the insulation layer is removed up to the conductor layer, i.e. the top and/or bottom of the conductor layer is exposed to enable the production of a direct electrical connection thereto. For example, connectors are known which comprise a connector area and a through-passage opening which is centrally arranged therein. The through-passage opening is provided, for example, to allow the passage of a mounting screw and for mounting a component or contact on the conductor layer. A number of slots, extending radially from the central axis of the opening in the shape of a star, is then introduced by means of punching in the section of the connector area of the exposing conductor layer adjoining the through-passage opening, and the connection area is then mechanically shaped, at least in the area of the slots, in the direction of the central axis of the through-passage opening, for example by deep-drawing or by means of other suitable mechanical machining methods. The connection area, at least in some sections, is thus convex in the direction of the central axis and as a result of the spreading of the segmentation defined by the star-shaped slot structure that is generated by the mechanical deformation, forms a number of connection segments. A disadvantage of this known production of such connection segments is that due to the punching process it is time-consuming and costly, because after the production of the basic shape of the respective busbar from a plate-shaped base material using lasers, the forming process must be followed by a punching process, which requires an exact alignment of the laser-generated plate-shaped base body in relation to the punching tool. Such punching tools are also subject to a high level of wearing. A further disadvantage is that the punching process only allows slots with a specified minimum width to be produced, resulting in a significant loss of material in the connection area and leading to a reduction in the contact surface of the connection area available for contacting. The material thickness that can be punched is also limited, and in fact the thickness of the required punching tool increases with the material thickness of the plate-shaped body, which in turn leads to a deterioration in the punching quality, in particular with regard to the uniformity of the punched slots. In particular, with increasing material thickness the edges of the punched slots are sharp and by no means straight, so that slots with non-uniform edge profiles are disadvantageously formed.

On the basis of the above mentioned prior art, the object of the invention is to specify a busbar in which the aforementioned disadvantages are eliminated, and which in particular can be produced in a time- and cost-optimized way from a plate-shaped base material. The object is achieved by a busbar in accordance with claim 1.

The essential aspect of the busbar according to the invention is that the connection segments are produced by introducing the slots into the connection area by means of laser radiation and preferably subsequent deformation of the connection area along the central axis. It is particularly advantageous that both the introduction of the slots into the respective connection area and the separation of the plate-shaped base bodies from a raw material, preferably a large plate-like raw material, are produced in particular in a single operation by laser cutting. The punching process known from the prior art, downstream of the existing laser cutting process, is eliminated and therefore also the cumbersome handling of the plate-shaped bodies cut from the plate-shaped raw material using the laser. This means that a time- and cost-intensive operating step can be saved.

Advantageously, the introduction of the slots into the connection area by means of laser radiation can be performed before or after the deformation of the connection area, wherein the introduction of the slots after the deformation step guarantees an approximately constant slot width, and by introducing the slots before the

deformation, it becomes possible to produce slots which widen out in the direction of the through-passage opening. By the choice of the sequence of processing steps therefore, the shape and/or width of the slots can be advantageously adjusted.

In addition, by means of the laser unit slots can be produced with significantly reduced slot widths in comparison to the punching method, the slot width being specifically less than 0.2mm, for example in relation to a conductor layer made from copper with a layer thickness of 2mm. By comparison, using the punching method, only slots with slot widths approximately equal to the layer thickness of the respective conductor layer or copper layer can be produced, i.e. in the exemplary embodiment considered, slots with slot widths of approximately 2mm. Advantageously therefore, almost a doubling of the contact surface of the segmented connection area is obtained due to the lower amount of material removal.

More advantageously, the plate-shaped base body is generated by cutting from a plate-shaped raw material by means of laser radiation, and specifically, the plate- shaped base body and the slots are produced in a single operation or several operations.

The connection segments are preferably arranged in a ring around the through- passage opening, wherein the connection area is then segmented, at least next to the through-passage opening, into the connection segments separated from each other by slots, namely by introducing the slots into the connection area by means of laser radiation, i.e. using a laser unit.

In a design variant the through-passage opening can also be produced by cutting out the conductor layer by means of laser radiation, wherein for this purpose a circular slot or two semi-circular slots are preferably introduced into the respective connection area using laser radiation.

It is also advantageous for the connection segments to be arranged concentrically around the through-passage opening. Preferably, the connection area has a circular, square or rectangular shape.

Particularly advantageously, the slots introduced into the conductor layer by means of laser radiation have a star-shaped slot structure, wherein the slots have a slot width of less than 0.2 mm and/or a slot width which is less than 0.1 times the layer thickness of the conductor layer, and/or the introduced slots are widened after the deformation or become widened due to the deformation process.

The terms "approximate", "substantially" or "approximately" in the context of the invention mean deviations from each exact value by +/- 10%, preferably by +/- 5% and/or deviations in the form of variations which are insignificant to the functionality.

Extensions, advantages and application possibilities of the invention also arise from the following description of exemplary embodiments and from the drawings. All features described and/or depicted in principle form the subject matter of the invention either alone or in any combination, regardless of how they are drawn up in the claims or by reference thereto. The content of the claims is also considered part of the description.

Hereafter the invention is explained in more detail by means of exemplary

embodiments illustrated in the figures. It is shown in :

Fig. 1 a simplified schematic plan view of a busbar according to the invention,

Fig. 2 a schematic plan view of a connection area of the busbar according to the invention as shown in Fig. 1,

Fig. 3 a schematic section along the line A-A through the busbar as shown in

Fig. 1,

Fig. 4 a schematic section along the line A-A through the busbar according to the invention as shown in Fig. 1, with a screw-type connection means received in the through-passage opening,

Fig. 5 a schematic cross-section through a busbar according to the invention comprising two conductor layers,

Fig. 6 an alternative embodiment of the busbar shown in Figure 4;

Fig. 7 a plan view of the connection area of a connector of a busbar after the introduction of a slot structure by means of lasers, and

Fig. 8 a plan view of the connection area of a connector of a busbar after the introduction of an alternative slot structure by means of lasers.

Figure 1 shows in a simplified schematic diagram a plan view of a busbar designed according to the invention for the transmission and distribution of electrical power and/or electrical signals within technical systems, for example in the field of electrical mobility, wind power or transport technology.

Such busbars comprise a plate-shaped base body 1, which comprises at least one or more plate-shaped busbar section(s). The plate-shaped base body 1 of such busbars 1 has a top 1.1 and a bottom 1.2 opposite thereto, which extend substantially parallel to each other and/or at least in some sections are level or flat. In the present exemplary embodiment, the plate-shaped body 1 comprises a rectangular basic shape. It is understood that a base body 1 can comprise almost any arbitrary basic shapes and/or different busbar sections connected together. Often, the specific form of the base body 1 is adapted to suit the respective application or distribution task within a technical system.

For example, a busbar, or its plate-shaped base body 1, can also comprise flat plug connection elements , 1", 1"', by which an electrically conductive connection can be established between two or more busbars 1, i.e. such busbars 1 can be designed in a modular way, and can be connected together quickly and easily by means of appropriately arranged, preferably edge-mounted, plug connection elements , 1 ", 1"' . This allows, for example, an extension of the connection possibilities of a busbar 1 to be achieved .

The plate-shaped base body 1 comprises at least one conductor layer 2, in particular a metallic layer for transmitting electrical power or electrical signals. The at least one conductor layer 2 is preferably produced from copper, aluminium or a metal with comparable electrical properties. The conductor layer 2, for example, has a layer thickness of between 0.5 mm and 8 mm, preferably between 0.8 mm and 6 mm.

The conductor layer 2 further comprises a top 2.1 and a bottom 2.2, which are preferably configured to be level or flat and each of which is adjoined by an insulation layer 3, 4. The insulation layer 3, 4, is produced for example as a plastic layer, in particular a reinforced fibreglass layer or as a laminate layer made of polyester, polyimide or materials which are suitable for lamination and having comparable dielectric properties. The layer thickness of the insulation layer 3, 4, for example, if designed as a plastic layer, is between 0.5 mm and 3 mm and if designed as a laminate layer, between 0.2 mm and 1.5 mm. The insulation layers 3, 4 have an insulation resistance required for the distribution of electrical power in the low-voltage range.

In the present exemplary embodiment, in accordance with Figures 1 to 4, the base body 1 of the busbar has a conductor layer 2 and a first and second insulation layer 3, 4, the first insulation layer 3 being connected to the top 2.1 of the conductor layer 2 and the second insulation layer 4 to the bottom 2.2 of the conductor layer 2. The connection is preferably effected by adhesive bonding of the respective layers using a suitable adhesive. In an alternative design variant in accordance with Figures 5 and 6, the base body of the busbar 1 comprises a first and second conductor layer 2, 2a and a first to third insulation layer 3, 4, 4', wherein the first and second conductor layer 2, 2a, are insulated from each other as well as from the outside by means of the aforementioned insulation layers 3, 4, 4". The first and second conductor layer 2, 2a could also be arranged in a plane one behind the other and electrically isolated from each other, which are then insulated from the outside via the first and second insulation layer 3, 4, and if necessary from each other via an additional intermediate insulation layer. To distribute the electrical energy or electrical signals provided via the conductor layer 2 or the first and second conductor layer 2, 2a, the basic body 1 comprises multiple connectors 5, 5', 5", which are formed by an appropriately prepared and/or moulded section of the relevant conductor layer 2, 2a. In particular, the connector 5, 5', 5" is spatially limited by a connection area 6, on which the first and/or second insulation layer 3, 4 are preferably completely removed and the conductor layer 2 or its top and/or bottom 2.1, 2.2 is therefore freely accessible.

The connection area 6 of a connector 5, 5', 5", is generated by, for example, introducing a breakthrough or a recess into the insulation layer 3, 4, which can be designed for example with a circular, square or rectangular shape. Alternatively, the connection area 6 can be already left open during creating the insulation layer 3, 4, for example by appropriate masking techniques. This makes the conductor layer 2, which is inherently insulated from the outside by means of the insulation layers 3, 4, directly and freely accessible for connection of an electrical component or a connecting conductor or an electrical conductor in the connection area 6.

In the present exemplary embodiment as shown in Figure 1, for example, a first to third connector 5, 5', 5" with a circular connection area 6 are provided. The

connectors 5, 5', 5" can be designed identically to each other or have a different structure, in particular they can be designed for connecting different types of components.

For example, connectors 5, 5' are provided, which have a connection area 6, in which the surface of the first and second insulation layer 3, 4 is removed, and in which a through-passage opening 7 is provided in the centre of the connection area 6, wherein the through-passage opening 7 is provided to allow the passage of a rod-shaped or screw-type connection means 8, specifically to allow the passage of a shaft section 8.1 of a screw-type connection means 8. The connection area 6 is also segmented into multiple connection segments 6a, 6b, 6c, 6d, 6e, 6f separated from each other by slots 9a, 9b, 9c, which extend in a star shape relative to the central axis MA of the through-passage opening 7 and are designed to be convex at least at the free end, wherein the connection segments 6a, 6b, 6c, 6d, 6e, 6f are produced by introducing the slots, 9a, 9b, 9c into the connection area 6 by means of laser radiation and by deformation of the connection area 6 along the central axis MA. The connection area 6 can be deformed either before the introduction or after the introduction of the slots, 9a, 9b, 9c. The plate-shaped base body 1 is preferably generated by cutting it from a plate- shaped raw material by means of laser radiation, namely in a laser machining step. At least one laser unit is provided for this purpose, which in a first operation cuts the plate-shaped body 1 of a busbar 1 from the plate-shaped raw material which comprises the previously described conductor layers and insulation layers 2, 2a, 3, 4. The desired connection areas 6 can be preferably generated even before this process step, by appropriate removal of an existing insulation layer or recessing of the conductor layer 2, 2a when laminating the conductor layer 2, 2a. The through-passage openings 7 can also be introduced into the plate-shaped bodies by means of the laser radiation even before the separation of the plate-shaped raw material.

The separation of the plate-shaped base boies 1 and the slots 9a, 9b, 9c necessary to produce the curved connection segments 6a, 6b, 6c, 6d, 6e, 6f are then generated according to the invention by means of the laser unit in a single operation. Then, in a subsequent operation, the connection area 6 provided with the slots 9a, 9b, 9c and segmented thereby is appropriately deformed, so that convex connection segments 6a, 6b, 6c, 6d, 6e, 6f are produced, the curvature of which extends along the central axis MA and therefore perpendicular to the top and/or bottom of the plate-shaped base body 1. In this way slots 9a, 9b, 9c can be introduced that extend over almost the entire diameter of the connection area 6, intersecting the central axis MA.

Alternatively, multiple slots (not shown in the Figures) extending outwards in a radiating pattern from the central axis MA can also be used.

Advantageously the plate-shaped base body 1 and the slots 9a, 9b, 9c are produced in a single operation, which means that the punching of the slots known from the prior art, which takes place in an intermediate operation downstream of the laser machining step, can be avoided.

The through-passage openings 7 can also be produced by cutting them out of the conductor layer 2 at the same time as the slots 9a, 9b, 9c by means of the laser radiation, for example by introducing a circular slot 9 or two semi-circular slots 9' in the connection area 6. The circular slot 9 or the semi-circular slots 9' then extend concentrically around the central axis MA. The through-passage opening 7 is then formed by the deformation of the connection area 6 using a suitable forming tool, for example using a deep-drawing tool.

The connection area 6 is therefore segmented, at least next to the through-passage opening 7, into the connection segments 6a, 6b, 6c, 6d, 6e, 6f separated from each other by slots 9a, 9b, 9c, namely by introducing the slots 9a, 9b, 9c into the connection area 6 by means of laser radiation.

The slots 9a, 9b, 9c preferably form a star-shaped slot structure. The width of the slots 9a, 9b, 9c is approximately constant and/or less than 0.2 mm, preferably between 0.1 mm and 0.2 mm. Preferably, the slots 9a, 9b, 9c introduced into the conductor layer 2, 2a in the connection area 6 by means of laser radiation have a slot width of less than 0.1 times the layer thickness of the conductor layer 2, 2a.

In an alternative design variant, the slots 9a, 9b, 9c, or this star-shaped slot structure, are generated after the deformation of the connection area 6 along the central axis (MA) and the resulting production of the desired convexity, and namely according to the invention by means of laser radiation. The subsequent introduction of the slots, 9a, 9b, 9c or star-shaped slot structure avoids the widening of the slots 9a, 9b, 9c using the forming process, i.e. the slots 9a, 9b, 9c are already produced with the final slot width in the connection area 6, wherein the slot width is approximately constant in the longitudinal direction of the slots, and dependent on the quality of the laser unit used. Advantageously, the slots 9a, 9b, 9c generated by the laser radiation are enclosed by edge sections of the first conductor layer 2 having a uniform profile.

In the design variants of a busbar according to the invention shown in the exemplary embodiments, the segmented connection area 6 extends in a ring around the central through-passage opening 7 and is convex in the direction of the top or bottom 2.1, 2.2 of the conductor layer 2, 2a in order to create a receiving space 10 for the screw head 11.2 or a threaded nut of a screw-type connection means 11, i.e. it extends along the central axis MA of the central through-passage opening 7 in accordance with Figure 3. This results in connection segments 6a, 6b, 6c, 6d, 6e, 6f which are approximately triangularly shaped in plan view.

The dimensioning of the overall thickness of the busbar or plate-shaped base body 1 is such that the convex part of the connection segments 6a, 6b, 6c, 6d, 6e, 6f is approximately flush with the top 1.1 of the plate-shaped base body 1. The curved connection segments 6a, 6b, 6c, 6d, 6e, 6f thereby form the receiving space 10, which adjoins the through-passage opening 7 along the central axis MA and is open in the direction of the bottom 1.2, that is designed for receiving the head section 11.2 of the screw-type connection means 8, being designed in such a way that the free end of the head section 8.2 terminates at least flush with the underside 1.2 of the plate-shaped base body 1, or comes to rest below it.

In an advantageous design variant at least three, preferably 4 to 12 connection segments 6a, 6b, 6c, 6d, 6e, 6f are provided. The connection segments 6a, 6b, 6c, 6d, 6e, 6f can each form a connection area that is approximately coextensive with respect to the central axis MA, the surface of which has the shape, for example, of a quarter, sixth or eighth of a circle. Figure 5 and 6 each show a design variant of the plate-shaped base body 1 with two conductor layers 2, 2a, wherein in the design variant in accordance with Figure 5 the first conductor layer 2 has a connection area 6 and in the design variant according to Figure 6 the second conductor layer 2 has the connection area 6. Figure 7 and 8 each show the connection area 6, shown exposed, of a plate-shaped material provided for producing the busbar, in which the slots 9a, 9b, 9c are introduced with or without a circular slot 9 by means of a laser. The star-shaped slot structure is clearly seen here. Figure 7 shows an advantageous design variant of the slots, 9a, 9b, 9c, in which the free ends of the slots, 9a, 9b, 9c open out into a circular opening that has a diameter greater than the slot width. This prevents an undesired formation of cracks in the area of the free ends of the slots, 9a, 9b, 9c in the connection area 6 during the deformation process.

In a preferred design variant, the conductor layer 2, or first and second conductor layer 2, 2a, is provided with a coating at least in the connection area, for example a titanium coating or a nickel coating or a silver coating or a gold coating, in order to improve connection capabilities, for example the production of a soldered or brazed joint. The invention has been described above based on exemplary embodiments. It is understood that numerous changes and modifications are possible without departing from the inventive idea underlying the invention. ₁

Reference list plate-shaped body

r, l", " plug connection elements

1.1 top

1.2 bottom

2 first conductor layer

2a second conductor layer

2.1 top

2.2 bottom

3 first insulation layer

4 second insulation layer

4' additional insulation layer

5, 5\ 5" connector

6 connection area

6a, 6b, 6c, connection segments

6d, 6e, 6f connection segments

7 through-passage opening

8 screw-shaped connection means 8.1 shaft section

8.2 head section

9 circular slot

9' semi-circular slot

9a - 9c slots

10 receiving space

MA central axis

Claims

Patent Claims

A busbar having at least one base body ( 1) which is plate-shaped at least in sections, with a top ( 1.1) and a bottom ( 1.2), comprising a conductor layer (2, 2a) and at least one first and second, insulation layer (3,

4) connected to the conductor layer (2, 2a) and with a plurality of connectors (5, 5', 5"), wherein at least one connector (5, 5',

5") comprises at least one connection area (6) and a through-passage opening (7), positioned centrally in the connection area (6) and extending along a central axis (MA), and wherein in the connection area (6) the first and second insulation layer (3, 4) are removed over some of the surface area, in which the connection area (6) is segmented into a plurality of connection segments (6a, 6b, 6c, 6d, 6e, 6f), separated from each other by means of slots (9a, 9b, 9c, 9, 9'), which extend in a star shape with respect to the central axis (MA) and which are convex at least at the free ends,

characterized in that the connection segments (6a, 6b, 6c, 6d, 6e, 6f) are produced by introduction of the slots (9a, 9b, 9c) into the connection area (6) by means of laser radiation and a deformation of the connection area (6) along the central axis (MA).

The busbar according to claim 1, characterized in that the plate-shaped base body ( 1) is produced by cutting from a plate-shaped raw material by means of laser radiation.

The busbar according to claim 2, characterized in that the plate-shaped body ( 1) and the slots (9a, 9b, 9c) are produced in a single operation or a plurality of operations.

The busbar according to any one of claims 1 to 3, characterized in that the connection segments (6a, 6b, 6c, 6d, 6e, 6f), are arranged around the through-passage opening (7) in the form of a ring.

The busbar according to any one of claims 1 to 3, characterized in that the connection area (6) is segmented, at least next to the through-passage opening (7), into the connection segments (6a, 6b, 6c, 6d, 6e, 6f) which are separated from each other by slots (9a, 9b, 9c), namely by introducing the slots, (9a, 9b, 9c) into the connection area (5.1) by means of laser radiation.

6. The busbar according to any one of claims 1 to 5, characterized in that the through-passage opening (7) is produced by cutting out the conductor layer (2) by means of laser radiation and/or in that the slots (9a, 9b, 9c) are introduced into the connection area (6) by means of laser radiation before or after the deformation of the connection area (6) .

7. The busbar according to any one of claims 1 to 6, characterized in that the connection segments (6a, 6b, 6c, 6d, 6e, 6f), are arranged concentrically around the through-passage opening (7) .

8. The busbar according to any one of claims 1 to 7, characterized in that the slots introduced into the conductor layer (2) by means of laser radiation form a star-shaped slot structure.

9. The busbar according to any one of claims 1 to 8, characterized in that the slots (9a, 9b, 9c) introduced into the conductor layer (2, 2a) in the connection area (6) by means of laser radiation have a slot width of less than 0.2 mm and/or in that the slots (9a, 9b, 9c) introduced into the conductor layer (2, 2a) in the connection area (6) by means of laser radiation have a slot width which is less than 0.1 times the layer thickness of the conductor layer (2, 2a) .

10. The busbar according to any one of claims 1 to 9, characterized in that the slots (9a, 9b, 9c) introduced before the deformation are widened by the deformation process.