EP4239803A1 - Claws pin - Google Patents

Abstract

The invention relates to a contact plug for transmitting electrical energy through detachable contacting with a contact socket, the contact plug being designed as a clawed pin, in that it has at least one claw-shaped element which deforms as a result of temperature changes and a change in the normal contact force between the clawed pin and the contact socket realized.

Description

The invention relates to a contact plug for transmitting electrical energy through detachable contact with a contact socket.

Plug connections, contacting elements, pole connectors, sockets, etc. are used in a wide variety of configurations and variants to make contact or produce detachable electrically conductive connections. In particular, but not exclusively, for electrical contacting tasks in the higher power range, contact systems have been developed which are based on round contact geometries to accommodate a contact pin and whose starting material consists of a flat contact grid that is brought into the round contact geometry with hyperbolic twist. These contact systems, which have become known as RADSOK, are characterized by robust and high-density contact production as a result of the considerable contact area with the respective contact pin. Alternatively, instead of the hyperbolic twisting situation, inwardly directed lamina geometries are known, the lamina contact grid of which is aligned radially symmetrically.

These contact geometries, which are preferably used as high-current contact sockets, are consequently known as radial contact sockets or hyperbolic contact sockets.

RADSOK contact systems of the aforementioned type are accommodated in connector bushings via their generally cylindrical outer contours and establish contact on the outside via the cylindrical surfaces. The DE 10 2007 051 266 B4 is based on the basic idea of providing a single connector socket sleeve that is designed in such a way that different lamellar contact cages in the form of RADSOK contact sockets can be accommodated, which come to rest flat on the inside of the contact sleeve.

A comparable basic structure is shown in DE 20 2016 100 095 U1 . The subject of the invention here is the coupling, connection, contacting of the cylindrical lamellar cage "on the fly" within the receiving connector socket sleeve in that only one of the respective end-side collars is fixed in the socket, for example by a press fit. An electrical connector socket is provided, comprising a cylindrical socket sleeve, which is designed with a receiving space in which a cylindrical lamellar cage with a large number of parallel running contact lamellas is inserted, wherein the lamellar cage has a first and second peripheral web at the end, between which the contact lamellae run. The lamellar cage is fixed at one end at least axially and preferably also non-rotatably in the bushing sleeve and thereby clamped or fastened, and at the other opposite end there is an axial slide bearing that can be rotated at least by a certain angle of rotation relative to the bushing sleeve. The laminated cage is preferably fastened with its one collar web to the inner wall of the bush sleeve by means of fastening means on the sleeve side.

Particularly when it comes to contacting tasks in the high-current range - for example for charging batteries in electrically powered vehicles or making electrical contact between the vehicle battery and the consumers in the vehicle - it is of particular importance that the electrical contacting of the plug-in connection partners is very reliable. Different influences can act on such plug-in connections and their contacting elements, which are often made up of one or more pairs consisting of plug contact pin and plug contact socket, for example mechanical loads, vibrations, impacts, aging influences. Considerable temperature influences caused by environmental conditions or as a result of self-heating caused by the flowing electrical power and the inherent resistance of the live parts are also possible. Self-heating can be particularly relevant at the contact points, since the contact surfaces can be small due to the contact force and there can therefore be a quasi-geometrically caused high resistance. For this reason, it is of particular importance that the contact force - more precisely: the contact normal force - is as high and constant as possible in order to press the contact partners, usually formed by contact pin and contact socket for their electrical contacting, together on their contact surfaces.

The contact sockets available in the prior art, such as the mentioned RADSOK sockets or their plug-in contact partners, the plug-in contact pins, both plastic shaping processes such as stamping, rolling and suitable materials with resilient properties are used in order to generate the desired spring effects through restoring forces that are used in order to preferably generate elastic contact pressure forces of the contact partners on their contact surfaces. The performance of the plug-in contact connection is limited by the effects of temperature, because higher temperatures cause a loss of spring force as a result of relaxation processes, material creep and internal stress reduction. This is especially true for copper and Copper alloys, since copper, in addition to its generally low elasticity, becomes "soft" above all at low temperatures.

If the plug-in contact partners are designed in this way and made of materials such as spring steel, it is possible to generate very high normal contact forces that reliably press the contact surfaces of the plug-in contact partners together, but assembly problems often arise because plugging the contact partners together requires high plug-in forces, which make assembly difficult or require the use of tools.

In order to reduce the problem of normal contact forces that decrease under the influence of temperature, contacting solutions have been developed in which the contacting elements or additional components deform as a result of the temperature increase in such a way that the increase in contact force is achieved and at the same time the assembly force when plugging the connector together is lower at lower temperatures. The EP 2 461 427 B1 discloses an automatically deforming high-current contact based on the approach, on the one hand, by designing the high-current contact constructively and, on the other hand, by providing an element of the plug-in connection that deforms automatically as the temperature rises, with low plug-in forces at room temperature for assembly and high contact force or normal contact force during operation, in particular greater self-heating and at elevated ambient temperatures.

The contact normal force is increased in a quasi self-regulating manner as soon as the temperature rises. The proposed high-current contact is used to transmit current from a power source to an electrical conductor of a current collector, so that the high-current contact together with the corresponding contact pin on the one hand for mechanical connection and on the other hand for electrical contacting of the current collector with the current source via an electrical contact surface of the high-current contact with the contact pin serves. By increasing the mechanical connection when the temperature of the high-current contact increases due to the flow of current through the high-current contact or the automatically deforming components, in particular an annular element, through the temperature-induced deformation, the material-related contact normal force loss is counteracted and the contact force is at least maintained, sometimes even increased. At the same time, mating is possible at low temperatures with reduced insertion force.

The follows a similar approach DE 10 2005 032 462 A1 . The contact socket is taught here to be designed in such a way that at least the area of the contact tips consists of a bimetal. The area formed with the bimetal changes its shape due to an influence of heat. This change in shape is used to at least keep the contact normal force constant or allow it to increase.

The contacting solutions available in the state of the art with the temperature-dependent change in the contact normal force and constructed through the combination of contact socket and contact pin sometimes have considerable disadvantages. Solutions are often found which have one or more components, such as rings or tubular components, which affect the contact normal force as a result of a temperature change. These solutions are complex, require multi-part contact arrangements, are therefore more difficult to assemble and have an increased potential for incorrect assembly. This results in economically unfavorable solutions and promotes malfunctions.

Other contact configurations integrate the components of the contact or plug connection that deform under the influence of temperature into the contact socket component. With such geometric configurations, the contact normal forces can only be influenced and in particular increased to a comparatively small extent by the temperature-dependent deformation. The heating process of the integrative deformation components can also take a considerable amount of time - this is caused by the one-piece structure with the contact element.

The object of the invention is to further develop the existing contacting solutions with contact normal forces that can be changed by the action of temperature and to at least partially reduce the existing disadvantages.

In order to solve the problem, the invention proposes a contact plug, plug-in contact pin, which interacts with a contact socket and consists of a multi-layer metal or a shape-memory alloy, which has a claw-like shape. The claw-like shape is formed by at least one claw-like, approximately circular arc-shaped element that partially extends in areas in the circumferential direction of the plug contact pin, preferably transversely to the direction of insertion of the plug contact pin into the contact socket. The at least one claw-like element extends, starting from a base element, which has a continuously continuous and largely linear shape with a flat surface in the insertion direction or has a slightly curved cross-section, in some areas, so that the contact pin does not have a closed, cylinder-like overall contour and the at least one claw-like element can be deformed at the end. The invention preferably provides two or more claw-shaped elements. From a functional point of view, the base element in this case is practically similar to the spine of the human skeleton, in which the ribs (here: claw-shaped elements) are attached and extend transversely to the spine's direction of extension.

The claw-shaped elements with their arc-like shape extending in regions in the circumferential direction form sections of a cylinder-like outer contour of the contact pin and have a constant or a changing radius in the circumferential direction. A radius that decreases towards the end of the extension of the claw-like elements is particularly advantageous, so that the shape of the claw-like elements, which is similar to a circular arc, virtually rolls up. In this way, the deformation behavior triggered by temperature changes of the claw pins, contact plugs made of multi-layer metal or a shape memory alloy and the resulting contact normal force can be additionally influenced geometrically.

A further, geometrically determined influencing of the temperature change-induced contact normal force by deformation of the spring-elastic, claw-shaped elements consisting of a multi-layer metal or a shape-memory alloy is provided by the invention through unequal width design. The width of the claw-shaped elements, ie their extension in the direction of insertion (axial direction of the contact pin) and thus transversely to the claw-shaped, arc-like shape, can increase from the first claw-shaped element arranged in the direction of insertion to the other claw-shaped elements located behind it in the direction of insertion. This results in a deformation behavior of the claw-shaped elements that differs depending on the width, in that claw-shaped elements with a smaller width are subject to faster temperature changes due to the smaller total mass with the same thermal energy exposure. As a result, a contact normal force change is accomplished at different times in time by the action of the multilayer metal structure or the shape memory alloy and the resulting deformation.

At the opposite end of the contact pin in the insertion direction, a protruding section of the base element can be provided as a functional element that can be used to attach (e.g. crimp or weld) an electrical line or cable or as a handle in the sense of a handling aid.

According to the invention, it is provided that at least the claw-shaped elements or even the entire contact pin consist of a multi-layer metal material, which is constructed, for example, as a bimetal from two types of material. It is advantageous to form the outer area of the claw-shaped elements or the contact pin with its contact surfaces towards the contact socket from a copper material and the inner area, d. H. to build the areas of the claw-shaped elements or the contact pin facing away from the contact socket on a steel material. Since the copper material and the steel material have thermal energy-induced expansion behavior that differs from one another, the bimetallic material deforms and triggers a deformation of the claw-shaped elements, which are used to influence the contact normal force. Layer structures with three materials can also be realized, in which the middle layer consists of a copper material and it is thus ensured that the multi-layer metal arrangement has good electrically conductive properties.

In a further embodiment, it is provided that the temperature-dependent deformation required to change the contact normal force takes place through the use of a shape memory alloy (also called memory metals) for the contact pin or for at least its claw-shaped elements.

It is possible according to the invention that the at least two claw-shaped elements are part of the contact socket instead of the contact plug. It is also possible for both the contact socket and the contact pin or contact plug to have claw-like elements. The explanations in the description also apply to these configurations.

The invention offers a number of advantages, especially when plugging together the contact partners consisting of claw pin and contact socket at room temperature, only low insertion forces are required, since the normal contact force is only increased by heating the claw pin and/or the contact socket contact and not by spring-elastic prestressing must be generated. The invention also achieves an increased Contact normal force with temperature change in the form of increasing temperature and thus decreasing electrical resistance. As a result of the increased contact normal force, there are high pull-out forces, ie forces for pulling the plug connection apart, at the operating temperature, with the result that plug connections of this type are less susceptible to vibration.

Economical mass production is supported by the fact that the geometrically simple contour of the starting material, semi-finished product, is very well suited for production using a stamping process. Solutions available in the prior art, in particular the so-called Radsok bushes, are very fine and have a large number of lamellae, which have a long punched edge and require high punching force.

Fig. 1

die perspektivische Ansicht auf den Kontaktstecker, der erfindungsgemäß als Krallenpin ausgestaltet ist;

Fig. 2

die perspektivische Ansicht auf den Krallenpin in einer gegenüber Fig. 1 abweichenden Blickrichtung;

Fig. 3

die Seitenansicht auf den Krallenpin;

Fig. 4

die perspektivische Ansicht auf die Kontaktpartner für eine elektrisch leitende Steckverbindung;

Fig. 5

die dreidimensionale Ansicht auf die Kontaktpartner für eine elektrisch leitende Steckverbindung;

Fig. 6

die räumliche Darstellung des endseitig in Steckrichtung gerichteten Krallenpins.

The invention is explained in more detail below using an exemplary embodiment in conjunction with the figures. show:

1

the perspective view of the contact plug, which is designed according to the invention as a claw pin;

2

the perspective view of the claw pin in a opposite 1 deviating line of sight;

3

the side view of the claw pin;

4

the perspective view of the contact partners for an electrically conductive plug connection;

figure 5

the three-dimensional view of the contact partner for an electrically conductive plug connection;

6

the spatial representation of the end of the claw pin in the plug-in direction.

figure 1 shows the perspective view of the contact plug, which is designed as a claw pin 20 according to the invention. The claw pin comprises at least two constructive-geometric elements which characterize the claw pin 20: a base element 30 and at least one claw-shaped element 50. The claw pin 20 can optionally be supplemented by at least one functional element 40.

The base element 30 functionally forms the backbone of the claw pin 20. Seen in the plug-in direction and largely parallel to the plug-in axis, it forms a continuously continuous and largely linear shape with a flat or slightly curved cross section, from which the at least one claw-shaped element 50 extends in the circumferential direction of the claw pin 20 and thus extends transversely to the plug-in direction.

The at least one claw-shaped element 50 extends in the circumferential direction of the claw pin 20 and forms a section of the cylinder-like contour of the contact plug. In the sectional plane lying axially to the claw pin 20, the at least one claw-shaped element 50 has one or more different radii of curvature R, R1, R2. Preferably, two claw-shaped elements 50 each lying at largely the same axial height of the claw pin 20 extend in the circumferential direction.

An optional functional element 40 can supplement the claw pin structure. The functional element 40 can extend in the opposite direction to the plug-in direction and be designed as an extension of the base element 30 . It can have a bore, tabs or other geometries that are suitable for providing additional functions, such as a handle to support handling when plugging the contact or plug-in connection partners together, consisting of contact socket 10 and claw pin 20 or for attaching a cable, a line (possibly . with a shield) by for example welding or crimping.

figure 2 includes the perspective view of the claw pin 20 in a opposite figure 1 different perspective. Shown is the optional configuration of a plurality of claw-shaped elements 50, which are arranged in pairs at an axial height of the claw pin 20 opposite and mirror-symmetrical to one another.

The claw width b is varied here in the manner shown qualitatively such that the width of the claw-shaped elements 50 can have two or more values that differ from one another. It is particularly advantageous to provide a width b of the first pair of claw-shaped elements 50 arranged in the plug-in direction with a width b1 and to realize a width b2 of the second pair of claw-shaped elements 50 arranged in the plug-in direction, where b1<b2. The width ratio can be varied as desired or kept constant over a number of claw-shaped elements 50 .

A width b1<b2<bn of the one or more first pairs of claw-shaped elements 50, which are arranged first in the insertion direction, is particularly advantageous. As a result of the lower mass of these narrower claw-shaped elements 50 compared to the pairs of claws located behind them in the plugging direction, this ensures faster heating of these narrower claw-shaped elements 50 after the mating of the contact partners and the electrical resistance when an electrical voltage is applied. In this way, a first contact normal force increase can be detected early and immediately be realized after the start of the current flow. Depending on the material used - multi-layer metals in the form of copper-steel combinations or shape-memory alloys - it has been shown that the width ratio b1/b2 of the first pairs of claw-shaped elements 50, which are arranged first in the plug-in direction relative to the claw pairs lying behind them in the plug-in direction, is particularly advantageous in a range of 0.3<=b1/b2<=0.8 and preferably about 0.5. These width ratios can be implemented in pairs or via several pairs of claw-shaped elements 50 with mutually equal width ratios (groups of the same claw width).

figure 3 illustrates the side view of the claw pin 20 viewed from the opposite direction to the plug-in direction, i.e. looking at the contact plug end in the direction of the contact socket 10. Starting from the base element 30, the two claw-shaped elements 50 shown here as examples extend in a parallel and mirror-symmetrical manner and form at least partially a cylinder-like shape Contour of the claw pin 20 with an opening OE opposite the base element 30.

The opening OE can optionally also be used to prevent the claw pin 20 from rotating within the contact socket 10 in the plugged-in state. For this purpose, a spring (not shown) can be provided in the contact socket, which engages in the opening OE and in this way prevents twisting by a mechanical stop.

The claw-shaped elements 50 extend in the circumferential direction of the claw pin 20 and have a shape similar to a circular arc. The circular shape-like curvature of this embodiment of the claw-shaped elements 50 is not constant in the direction of extension from the base element 30, i. H. the radius of curvature R becomes smaller at least in some areas as the extension away from the base element progresses, so that R1>R2. The reduction in radii can be continuous—as shown—or have jumps in radii. In addition to the choice of material and the temperature change, the configuration R2<R1 is an additional and geometrically determined possibility of influencing the change and increase in the contact normal force due to the effect of temperature changes.

As a result of the change in radii, the change in shape caused by temperature changes of the claw pins 20 made of multilayer metal or a shape memory alloy can also be influenced geometrically and the locally different deformation of the claw-shaped elements 50 can be used specifically to adjust and increase the resulting normal contact force. A radii ratio of 1.1<=R1/R2<=3 is particularly advantageous in the case of multilayer metals and in particular a bimetal structure as well as shape memory alloys.

figure 4 shows the perspective view of the contact partner 1 for an electrically conductive plug connection, here consisting of a claw pin 20, which is inserted at least in some areas into a contact socket 20. Due to the increase in the normal contact force due to temperature changes, the normal contact force does not have to be caused by the elastic deformation, or only to a reduced extent of the contact partners are generated before the effect of temperature. As a result, the insertion of the claw pin 20 into the contact socket 10 is easier and easier to assemble.

figure 5 shows the three-dimensional view of the contact partner 1 for an electrically conductive plug connection in the plugging direction. At the assembly temperature, which is preferably equal to the ambient temperature, the claw-shaped elements 50 are formed at the end of their extension and adjacent to the opening OE with a significant play in relation to the contact socket and in this way facilitate assembly.

figure 6 shows the spatial representation of the claw pin 20 directed at the end in the direction of insertion. This detailed view shows the bevel or chamfer F optionally realized in one or more claw-shaped elements 50. The chamfer F is provided here on the side and end of the claw-shaped elements 50 on the side in the direction of insertion. As a result, assembly, ie the mating of the contact partners 1 by inserting the claw pin 20 into the contact socket 10, is made even easier, because a quasi-sticking during the insertion movement is counteracted.

Reference sign

1

Contact partner for an electrically conductive plug connection

10

contact socket

20

Contact plug, claw pin

30

base element

40

functional element

50

claw-shaped element

b, b1, b2, bn

Claw width, width of the claw-shaped element

f

chamfer, bevel

OE

opening

R, R1, R2

Radius of curvature claw-shaped element

Claims (13)

Contact plug (20) for transmitting electrical energy by releasably contacting a contact socket (10), characterized in that the contact plug is designed as a claw pin (20), characterized in that it has at least one claw-shaped element (50) which deforms as a result of temperature changes and a change in the contact normal force between the claw pin (20) and the contact socket (10) is realized. Claw pin (20) according to Claim 1, characterized in that the at least one claw-shaped element (50) extends from a base element (30) in the shape of a circular arc with a radius of curvature R in the circumferential direction of the claw pin (20). Claw pin (20) according to Claim 2, characterized in that the at least one claw-shaped element (50) has a first radius of curvature R1 in the direction of extension starting from the base element (30) and a second radius of curvature R2 at the end of the extension. Claw pin (20) according to Claim 3, characterized in that the radius of curvature R1 is greater than the radius of curvature R2 and the radius ratio is in a range of 1.1<=R1/R2<=3. Claw pin (20) according to Claim 1, characterized in that the at least one claw-shaped element (50) has a bevel in the form of a chamfer F at the end of its extent. Claw pin (20) according to Claim 2, characterized in that at least one second claw-shaped element (50) extends from the base element (30) in the shape of a circular arc and is arranged in such a way that it is parallel and mirror-symmetrical to the first claw-shaped element in the axial direction of the claw pin (20). Element (50) is arranged so that a pair of claws is formed, which partially forms a cylinder-like outer contour of the claw pins (20). Claw pin (20) according to Claim 6, characterized in that the pair of claws has an opening OE. Claw pin (20) according to Claim 1, characterized in that a plurality of claw-shaped elements (50) are arranged in the axial direction of the claw pin (20). Claw pin (20) according to Claim 8, characterized in that the majority of the claw-shaped elements (50) have one or more different claw widths b. Claw pin (20) according to Claim 9, characterized in that the different claw widths b between two claw widths b1, b2 are in a ratio of 0.3<=b1/b2<=0.8. Claw pin (20) according to Claim 1, characterized in that at least one claw-shaped element (50) is formed from a multi-layer material or a shape-memory alloy with the property of undergoing a change in shape as a result of a change in temperature. Claw pin (20) according to Claim 2, characterized in that the base element (30) has a functional element (40) at the end opposite to the insertion direction of the claw pin (20). Contact partner (1) for an electrically conductive plug connection, consisting of a contact socket (10) and a claw pin (20) according to one of the preceding claims.

Images