Socket contact and method for manufacturing same
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- AMPHENOL TUCHEL IND GMBH
- Filing Date
- 2024-06-10
- Publication Date
- 2026-05-06
AI Technical Summary
Existing socket contacts with freely movable contact blades face challenges in maintaining high electrical conductivity while avoiding material deformation and impaired mating properties due to high surface pressures and plugging forces.
The introduction of grooves on the inside of contact lamellae increases the contact area and reduces surface pressure, enhancing contact force without risking material damage, by allowing for a larger contact surface and influencing structural strength and bending stress behavior.
This design increases the number of contact points and reduces the risk of plastic deformation, enabling safer transmission of higher electrical power with reduced electrical resistance and maintaining consistent outer dimensions for easy installation.
Smart Images
Figure EP2024065916_02012025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] SOCKET CONTACT AND MANUFACTURING METHOD THEREFOR
[0003] The invention relates to a socket contact for a detachable, electrically conductive plug connection, comprising a lamella section and a socket section, and a transition region between the socket section and the lamella section, wherein the lamella section has at least one contact lamella and a cylindrical receiving space with an inlet opening. The invention also relates to a method for producing a socket contact.
[0004] Plug connectors, contacting elements, pole connectors, receptacles, etc., in a wide variety of designs and variants are used to make contact or create detachable, electrically conductive connections. Particularly, but not exclusively, for electrical contacting tasks in the higher power range, contact systems have been developed that are based on round contact geometries for accommodating a contact pin. Their starting material consists of a flat contact grid that is formed into the round contact geometry with a hyperbolic twist. These contact systems, known as RADSOK, are characterized by robust and high-density contact production due to the substantial contact surface with the respective contact pin. Alternatively, instead of the hyperbolic twist situation, inward-directed lamellar geometries are known, whose lamellar contact grid is aligned radially symmetrically.
[0005] These contact geometries, which are preferably used as high-current contact sockets, are known as radial contact sockets, lamellar contact sockets or hyperbolic contact sockets.
[0006] Lamellar contact bushings can be used in a variety of geometric variations. Among other things, lamellar contact bushings are known in which the lamellae are formed integrally with the lamellar contact bushing at one or both of their ends along their longitudinal extension. This differing geometric structure of the lamellar contact bushing has a significant impact on the contact spring force of the lamellae, which is crucial for the contact properties with the contact partner necessary for transmitting electrical power. In lamellar bushings with an end-face bushing, the contact lamellae are formed integrally with the bushing section at one of their ends, while the opposite contact lamella end is freely movable. In classical mechanics, geometric situations of this type are referred to as a cantilevered bearing or a floating bearing.
[0007] For socket contacts, which detachably transmit electrical power in the high-voltage range through interaction with pin contacts and plug-in contact pins, different development goals have been pursued depending on the specific installation situation and application. In addition to cost-effective production and the simplest possible assembly, the lowest possible loss of electrical power transmission and resistance to both maximum loads and fatigue strength are of particular interest.
[0008] The published patent application DE 10 2014 105 534 A1 presents a teaching for improving the contact force of socket contacts in order to improve the electrical contact and thus the electrical conductivity of the plug connection. The socket contact presented has a base body which has a receiving space for receiving a pin contact, wherein the base body has at least two contact blades which are arranged such that they delimit the receiving space, wherein the contact blades each have at least one step along their length on an inner side facing in the direction of the receiving space, so that the receiving space has a first diameter D1 and a second diameter D2 which is different from the first diameter D1, wherein the first diameter D1 in front of the step is larger in the insertion direction of the pin contact than the second diameter D2 in the insertion direction behind the step.By having at least one step on the inside of the contact blades, the stress that occurs on the base body of the socket contact when a pin contact is inserted into the receiving space of the socket contact can be better distributed across the entire base body, so that voltage peaks on the base body can be avoided and the overall stress occurring on the base body can be reduced. In particular, at the base of the blades, i.e. where the contact blades are integrally connected to a rigid part of the base body, stresses that would otherwise normally occur can be reduced. By creating a step on the inside of each contact blade, the contact blade can act like a series-connected spring to reduce the stresses that occur when the socket contact makes contact with the pin contact.Due to the step and the resulting reduced voltage peaks, the contact normal forces achievable with the socket contact can be significantly increased.
[0009] DE 10 2016 123 935 A1 teaches a method for producing a socket contact comprising the steps a.) producing a hollow cylindrical contacting region at a first end of the round rod by means of extrusion, wherein the hollow cylindrical contacting region has first and second sections extending in the longitudinal direction of the contacting region, which are formed alternately next to one another in the circumferential direction of the contacting region, wherein the first sections have a thicker wall thickness and the second sections have a thinner wall thickness, followed by step b.) positioning the first sections with a thicker wall thickness inwards, wherein the second sections with a thinner wall thickness are bent or folded outwards.
[0010] DE 10 2019 113 608 A1 shows a generic socket contact.
[0011] The plug contact partners are, on the one hand, the tubular socket contact and, on the other hand, a bolt-shaped plug contact pin inserted into the socket contact. The socket contact has at least one slot extending axially in the longitudinal direction, thus forming a spring structure designed to clamp the plug contact pin and establish an electrically conductive contact when the plug contact pin is inserted into the socket contact.
[0012] In order to also handle very high electrical outputs, such as can occur briefly at the start of a charging process (so-called peak currents), DE 20 2016 100 761 U1 proposes a socket contact with improved dimensions to increase the electrically conductive properties for peak current resistance. Based on the knowledge that this can be achieved by increasing the contact force, the thickness of the contact blades and the length of the contact blades are specially coordinated. Accordingly, each contact blade has a thickness, measured radially in the direction of insertion, in a range between 0.5 mm and 1.5 mm and a length, measured along the direction of insertion, in a range between 5 mm and 15 mm. The disadvantage of existing solutions is that the focus is on increasing the contact force when trying to increase electrical conductivity with as little loss as possible.At the same time, the contact surfaces of the plug-in contact partners, consisting of the laminated contact socket and the plug-in contact pin, are often very small, resulting in considerably high surface pressures. This can exceed the strength of materials with good electrical conductivity, and plastic deformation (so-called "digging in") can occur. The mating properties of the plug connection are also impaired by high mating forces.
[0013] The object of the invention is to further develop socket contacts with contact blades that are freely movable on one side and to at least partially reduce the disadvantages existing in the prior art.
[0014] To achieve this goal, the invention proposes a geometric socket contact design in which at least one groove is incorporated on the inside of at least one contact blade. The invention recognizes that it is advantageous for the transmission of electrical energy to enlarge the contact area of the plug contact partners, consisting of the socket contact and the plug contact partner, in the form of a plug contact pin. This can be achieved in combination with an increased contact force, i.e. the contact pressure of the plug contact partners against each other at their contact surfaces, because the surface pressure decreases due to the increased contact area, all other things being equal. This means that the contact pressure can be increased with an increased contact area without running the risk of exceeding the material-related interface pressure and causing damage due to "digging in" through local plastic flow.
[0015] To implement the inventive concept, at least one groove is introduced into at least one contact blade on the inside of the socket contact, preferably with a cylindrical outer dimension. The at least one groove extends within at least one region in the longitudinal direction and thus axially to the socket contact and its contact blade. The at least one groove is introduced into at least one contact blade on the inside. In this way, the number of contact points per contact blade is increased compared to contact blades without grooves, because the contact blades with a curved longitudinal cross-sectional contour without grooves have only one contact point. The longitudinal extension of the at least one groove introduced into at least one contact blade can occur in a delimited region in which the contact and thus the contact surface between the contact blade and the plug contact pin is also located.This contact surface is limited to an axially positioned section by the curved longitudinal cross-sectional contour of the contact blade. The grooving can also extend longitudinally beyond this limited area, up to a complete longitudinal grooving of the contact blade. This makes it possible to specifically influence the structural strength of the contact blade and its bending stress behavior in order to change and preferably increase the resulting contact force between the contact blade and the plug contact pin within the contact surfaces located at the contact points. In addition to the longitudinal grooving extending partially or completely axially across the contact blade, the grooving can also extend axially beyond it into the transition area between the contact blade and the socket area and beyond.Especially in the transition area, the grooving can be used to influence the elastic deformation behavior of the contact lamella, since the bending stress is maximum in the transition area.
[0016] The invention is explained in more detail below using an exemplary embodiment in conjunction with the figures. In the figures:
[0017] Fig. 1 is a three-dimensional view of the socket contact;
[0018] Fig. 2 is a perspective view of a bushing blank;
[0019] Fig. 3 a spatial representation of the bushing blank with introduced grooving;
[0020] Fig. 4 shows the finished socket contact.
[0021] Figure 1 includes a three-dimensional view of the socket contact 1 with a seal 40 and a spring collar 50. The socket contact 1 has a lamella section 10 and a socket section 20 as well as a transition region 30 between the lamella section 10 and the socket section 20. The socket contact 1 has a hollow cylindrical basic structure and a cylindrical receiving space 60 for a plug contact pin (the plug contact pin is not shown), which extends axially inside the socket contact 1 and is matched to the shape and dimensions of the plug contact pin to be contacted. The socket contact 1 is constructed such that a plug contact pin can be inserted axially into the socket contact 1 at the end, preferably from the lamella section 10. The detachable, electrically conductive contact is made at contact surfaces on the inside of the socket contact 1 and the outer surface of the plug contact pin.
[0022] The lamella section 10 of the socket contact 1 has at least one contact lamella 12. In the exemplary embodiment shown, six contact lamellas 12 are provided. The at least one contact lamella 12 extends in the axial and end direction of the socket contact 1 from a transition region 30 and forms, at its end, an inlet opening 61 of the cylindrical receiving space 60 for a plug contact pin.
[0023] The contact blades 12 are fixed in the transition region 30 by a preferably one-piece design of the socket contact 1 and are movable at their opposite end and thus at the end of the socket contact 1. In this way, a basic construction of the "cantilevered beam" known from mechanics is created, which enables the contact blades 12 to exert elastic radial restoring forces and thus generate the contact forces. For the contact blade 12, a maximum bending stress arises at the clamping point, i.e. at the transition region 30 from the contact blade 12 to the socket section 20, when a force is applied radially to the contact blade 12. As a result of forces acting radially on the contact blades 12 or force directions with a radial component, which usually corresponds to the contact forces, the contact blades 12 deform in an elastic and, undesirably, possibly plastic manner.The contact forces can be increased by using an overspring 50 without increasing the bending stress load in the contact blade 12.
[0024] The at least one contact blade 12 is separated in its longitudinal extension by slots 13, so that the contact blades 12 are elastically deformable independently of one another and the inlet opening 61 of the cylindrical receiving space 60 can be expanded. To specifically influence the elastic properties and thus the deformation behavior of the contact blades 12, the contact blades 12 can have a constriction 12' in the form of a concave region of the outer contour adjacent to the transition region 30. Grooves 14 are introduced on the inside of the blade section 10. The grooves 14 are designed such that at least one contact blade 12 has at least one groove 14. Essentially, the grooves 14 extend longitudinally axially parallel to the center line of the socket contact 1 and the contact blades 12.
[0025] The invention provides the possibility that the longitudinal extent of the grooves 14 is limited to a section in which the contacting area of the socket contact 1 and the plug contact pin is located. This means that the longitudinal extent of the grooves 14 is partially limited to the contacting surfaces between the socket contact 1 and the plug contact pin. Depending on the design of the inner contour of the lamella section 10 and thus of the contact lamellas 12 with a chord-like, inwardly curved shape, the contacting surfaces can be located at different positions in the axial direction. In the exemplary embodiment shown, the axial longitudinal extent of the grooves 14 is approximately one-third of the axial length of the contact lamellas 12 and are arranged adjacent to the inlet opening 61 of the cylindrical receiving space 60.As an alternative to the region-wise extension adjacent to the inlet opening 61 of the cylindrical receiving space 60, the grooves 14 can extend axially over the entire length of the contact lamellae 12 and beyond into the inner transition region 30. In this way, the elastic properties and thus the deformation behavior of the contact lamellae 12 in the transition region 30 and the adjacent region of the contact lamellae 12 can be influenced.
[0026] The grooves 14 are designed in the circumferential direction, at least in some regions, as partial circle geometries and have at least one groove radius RR. The respective groove radius RR is selected such that it is smaller than the clear width and thus the radius of the cylindrical receiving space 60 for the plug contact pin (not shown). In addition, the groove radius RR can also be selected smaller than half the extension width of the contact blade 12 to be grooved in the circumferential direction of the blade section 10, so that at least two contact areas are created between a contact blade 12 and the plug contact pin. In addition to increasing the number of contact areas, it is advantageous that sharp edges are avoided and the risk of the contact blades 12 digging into the surface of the plug contact pin at the contact areas is reduced.The avoidance of sharp edges also reduces the mating forces required for the socket contact 1 and the plug contact pin. Compared to a known socket contact according to the prior art, the invention supports the same outer contour dimensioning regardless of the grooves 14 on the inside of the socket contact 1, so that the number of contact areas can be increased without changing the dimensions of the environment in which the socket contact 1 is accommodated—for example, the plug contact connector, contact interface, or plug contact module. The increased number of contact areas allows higher electrical power to be transmitted reliably and with reduced electrical resistance.The contact areas between the grooves 14 and the cylindrical surface of the plug contact pin (not shown) inserted into the cylindrical receiving space 60 are linear with a comparatively thin line width depending on the groove radius RR and can approach a point-like surface with very short longitudinal extension areas of the grooves 14. If the contact area is reduced, for example, by reducing the longitudinal extension of the groove 14, with the same contact pressure, the effective surface pressure between the contact blade 12 and the plug contact pin increases.
[0027] A further advantage of the possibility of consistent outer contour dimensions is the unchanging installation situation, even with regard to the use of the same seals 40 and / or oversprings 50.
[0028] Figure 2 comprises a perspective view of a socket blank as a semi-finished product or pre-product for the socket contact 1. The socket blank can be a turned part which already has the lamella section 10 and the socket section 20 as well as a sealing groove 21 and a spring groove 11.
[0029] Figure 3 shows a spatial representation of the bushing blank with at least one groove 14 introduced. Preferably, the grooves 14 are introduced into the lamella section 10, for example by removing material by milling or broaching, before the contact lamellae 12 are formed.
[0030] Figure 4 shows the finished socket contact 1. Starting from the socket blank with introduced grooves 14, at least one slot 13 is machined by separating or material-removing processes, so that at least one contact blade 12 is formed. After machining the at least one slot 13, if a plurality of contact blades 12 are formed, the contact blades 12 can be deformed inward and thus arcuately. List of Reference Symbols
[0031] 1 socket contact
[0032] 10 slat sections
[0033] 11 Overspring groove
[0034] 12 contact lamella
[0035] 12' constriction
[0036] 13 Slot
[0037] 14 Creasing
[0038] 20 socket section
[0039] 21 Sealing groove
[0040] 30 Transition area (contact blade to socket section)
[0041] 40 Seal
[0042] 50 oversprings
[0043] 60 cylindrical receiving space plug contact pin
[0044] 61 Entrance opening
[0045] RR grooving radius
Claims
Claims 1. Socket contact (1) for a detachable, electrically conductive plug connection, comprising a lamella section (10) and a socket section (20) and a transition region (30) between the socket section (20) and the lamella section (10), wherein the lamella section (10) has at least one contact lamella (12) and a cylindrical receiving space (60) with an inlet opening (61), characterized in that at least one groove (14) is introduced into the at least one contact lamella (12) on the inside of the lamella section (10).
2. Socket contact (1) according to claim 1, characterized in that the at least one groove (14) extends in the longitudinal direction substantially axially parallel to the center line of the socket contact (1) and the at least one contact blade (12).
3. Socket contact (1) according to claim 1, characterized in that the at least one groove (14) extends longitudinally on the inside into the transition region (30).
4. Socket contact (1) according to claim 1, characterized in that the at least one groove (14) extends in the longitudinal direction of the at least one contact blade (12) in one area.
5. Socket contact (1) according to claim 4, characterized in that the region extends in the longitudinal direction over approximately one third of the axial length of the at least one contact blade (12).
6. Socket contact (1) according to claim 4, characterized in that the region extends in the longitudinal direction in the section of the contact surface layer between the at least one contact blade (12) and a plug contact partner.
7. Socket contact (1) according to claim 4, characterized in that the region extends in the longitudinal direction adjacent to the inlet opening (61) of the cylindrical receiving space (60).
8. Socket contact (1) according to claim 1, characterized in that the at least one groove (14) has a partial circle geometry cross-section at least in some areas in the circumferential direction.
9. Socket contact (1) according to claim 8, characterized in that the pitch circle of the at least one grooving (14) has a grooving radius (RR).
10. Socket contact (1) according to claim 8, characterized in that the amount of the grooving radius (RR) is smaller than the radius of the cylindrical receiving space (60).
11. Socket contact (1) according to claim 8, characterized in that the amount of the grooving radius (RR) is less than half the extension width of the at least one contact lamella (12) in the circumferential direction of the lamella section (10).
12. Socket contact (1) according to claim 1, characterized in that the at least one contact blade (12) has a chord-shaped, inwardly bent cross-sectional shape in the longitudinal direction.
13. Socket contact (1) according to claim 1, characterized in that the outer contour of the socket contact (1) has a spring groove (11) and a sealing groove (21).
14. Socket contact (1) according to claim 1, characterized in that the outer contour of the lamella section (10) has at least one constriction (12').
15. A method for producing a socket contact (1) according to claim 1, characterized by the manufacturing steps: providing a socket blank as a semi-finished product or preliminary product in the form of a turned part with a lamella section (10) and socket section (20); introducing the at least one groove (14) into the lamella section (10); machining the at least one slot (13) so that at least one contact lamella (12) is formed.