EP4654400A1

EP4654400A1 - Connector with a common grounding plate having improved shielding properties

Info

Publication number: EP4654400A1
Application number: EP24177319.1A
Authority: EP
Inventors: Fabrice DEMOMENT; Quentin CORDIER
Original assignee: Aptiv Technologies AG
Current assignee: Aptiv Technologies AG
Priority date: 2024-05-22
Filing date: 2024-05-22
Publication date: 2025-11-26

Abstract

An electrical connector comprising:
- a plurality of terminals connected to a shielded cable comprising a cable shield surrounding a core wire,
- an insulating housing accommodating said terminals,
- a grounding cable with a grounding terminal (8),
- a common grounding plate (18) electrically connected both to the cable shields and to said free end of the grounding terminal (8).

The grounding plate (18) comprises an opening (21) with two flexible tongues (23) configured to be in electrical contact with the grounding terminal. Each flexible tongue (23) has two different bending zones (28, 29).

A method for manufacturing the grounding plate (18).

Description

TECHNICAL FIELD

The present disclosure relates in general to the field of electrical connectors, and in particular to the field of connectors for connecting shielded cables, such as shielded cables for high voltage current. Such connectors are intended to be used in any type of industry, and in particular in the automotive industry.

PRIOR ART

Connectors, and in particular power connectors for automotive applications, are known as being able to accommodate power terminals attached (e.g. crimped) to shielded cables. In such connectors, the grounding of the shielded cables is performed by harness makers who must splice the shielding braids of these shielded cables with a grounding wire that is itself connected to the vehicle body.
However, this harness preparation is quite complex and time-consuming. In particular the splicing must be done for each shielded cable individually. Moreover, such a technology creates complications for designing sealed connectors.
Further, it is suitable to have connectors with optimized EMC shielding properties (EMC stands for Electromagnetic Compatibility).
The disclosure below aims at improving, at least partially, the shielding and grounding of connectors.

SUMMARY

Indeed, it is disclosed below an electrical connector according to claim 1. This connector accommodates a plurality of terminals, each of which is respectively electrically connected to a shielded cable. However, this connector may accommodate one or several other terminals which are not connected to a shielded cable. For example, power terminals are connected to a shielded cable, whereas, signal terminals are not. Each shielded cable consists of a cable shield surrounding an electrically conductive core formed of at least one electrical wire. Each terminal electrically connected to a shielded cable is actually connected to the core of a shielded cable. At least one grounding cable has a free end located in said housing. At least one grounding terminal is electrically connected to the free end of a respective grounding cable accommodated in a cavity or a compartment formed in an insulating housing. Further, a common grounding plate is electrically connected both to the cable shields of the at least two shielded cables and to a grounding terminal. Therefore, the connector comprises an additional grounding means corresponding to a grounding cable allowing the cable shields (e.g. shielding braids) to be easily connected to an equipment ground (e.g., the vehicle ground). This solution avoids the complex and time-consuming task of splicing the shielding braid of each cable. The grounding plate has an opening. This opening has no function in itself. It is the result of an operation to cut flexible tongues. One can define a longitudinal direction in which this opening extends. At least two electrical flexible tongues are formed, each on a respective longitudinal side of the opening. In other words, each flexible tongue runs at least partially along a respective side of the opening parallel to the longitudinal direction. Each flexible tongue is configured to establish an electrical contact with a grounding terminal.
Further, each flexible tongue has two different bending zones, each around a line parallel to the longitudinal direction. In other words, these two bending zones are distinct from each other. That is to say, each flexible tongue does not have a continuous and/or unique curvature from the opening side (i.e., a distal bending zone) to its tip (i.e., a proximal bending zone).
Such a configuration allows two bending zones to be created, each with a specific function, while keeping the tongues small (i.e., along the dimension from the opening side to its tip. Indeed, the tongues are made relatively small (if not the smallest possible given the thickness of the grounding plate and the precision of the stamping tools and operations).
For example, the two different bending zones of each flexible tongue comprise a proximal bending zone configured to provide a smooth surface in contact with the grounding terminal, and a distal bending zone configured to flex when the grounding terminal is inserted into the opening. For example, the distal and proximal bending zones have a radius of curvature comprised between 0.1 and 0.2 millimetre.
Advantageously, the opening is the smallest possible so as to optimize the EMC shielding properties. For example, the opening extends over a surface of less than 16 square millimetres.
Possibly, the grounding plate has a thickness comprised between 0.2 and 0.3 millimetre, at least at the edge of the opening.
Advantageously, the opening comprises a slot parallel to the longitudinal direction and a triangular cut-out at each end of the slot. The triangular cut helps avoiding parts of sheet metal resulting from the cutting of the tongues from becoming trapped in the opening.
Advantageously, the slot has a length in the longitudinal direction equal to or greater than the dimension parallel to the longitudinal direction, of the contact surface of the grounding terminal with each flexible tongue. Such a configuration allows for reducing the opening size (so as to optimize the EMC shielding properties) and/or optimizing the electrical contact between the grounding plate and the grounding terminal (for a better conductivity and an improved efficiency of the grounding properties). The grounding terminal has a plate-like shape (i.e., a blade shape) with two contact surfaces (each on one side of the plate like-shape). The tongues therefore exert a symmetrical force on each of these contact surfaces. This configuration avoids twisting constraints that could be detrimental to holding the grounding terminal in place in its slot.
It is also disclosed below a method according to claim 8, manufacturing a grounding plate for an electrical connector.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, purposes and advantages of the disclosure will become apparent on reading the following detailed description given with reference to the appended drawings and by way of non-limiting examples and in which:

Figure 1 is a schematic representation in perspective of an example embodiment of a power connector assembly;
Figure 2 is a schematic representation in perspective of a power connector of the power connector assembly shown in Figure 1, this power connector being represented without its housing;
Figure 3 is a schematic cross-section of a portion of the power connector of the connector assembly shown in Figure 1;
Figure 4 is a schematic cross-section of a detail of the power connector shown in Figure 3;
Figure 5 is a schematic perspective view of an opening cut in a grounding plate accommodated in the power connector shown in Figures 2 to 3;
Figure 6 is a schematic cross-section of a portion of the grounding plate shown in Figure 5;
Figure 7 is a schematic perspective view of the opening shown in Figure 5, with tongues bent on the edges of this opening;
Figure 8 is a schematic cross-section of a portion of the grounding plate shown in Figure 7; and
Figure 9 is a schematic cross-section of a portion of the grounding plate shown in Figures 7 and 8, with a grounding terminal inserted in the corresponding opening.

DETAILLED DESCRIPTION

Figure 1 discloses an example of a connector assembly 1. The connector assembly 1 comprises a connector 2 and a counterpart connector 3. In this example, the connector 2 is a male connector and the counterpart connector 3 is a female connector. For example, both the connector 2 and the counterpart connector 3 are 4-way power connectors (with an additional way for the connector 2 as disclosed below). The connector 2 comprises in particular a housing 4 and a seal retainer 5, both made of a dielectric material. The connector 2 also comprises a common grounding plate 18 (see
Fig. 2), a single wire seal 16 (see Fig. 3) and a common seal 24 (see Fig. 3). The housing 3 has a plurality of compartments 6 (see Fig. 3). Each compartment 6 is configured for accommodating a terminal 7 (in this example a male power terminal) (see Fig. 2). A grounding terminal 8 is accommodated in a cavity 9 formed in the seal retainer 5 (see Figs. 3 and 4).
Each terminal 7 is mechanically attached and electrically connected to a shielded cable 10. For example, each terminal 7 is crimped on a shielded cable 10. Each shielded cable 10 is intended to transmit high power currents. Each shielded cable 10 comprises an outer sheath 11, an inner sheath 12, both made of electrically insulating material, an electrically conducting cable shield (e.g. a shielding braid) being inserted between the outer sheath 11 and the inner sheath 12. The inner sheath 12 envelops a core 13 formed of at least one electrically conductive wire. The cable shield surrounds the core 13 except at the end of the shielded cable 10, where the cable shield is turned up over the outer sheath 11. An electrically conducting ferrule 14 is mounted at the end of each shielded cable 10, on a portion of the cable shield which is turned up over the outer sheath 11.
The use of ferrules 14 is optional, but it improves the electrical connection between the common grounding plate 18 and the cable shields.
The grounding terminal 8 is mechanically attached and electrically connected to a free end of a grounding cable 15. For example, the grounding terminal 8 is crimped on the grounding cable 15. For example, the grounding terminal 8 is also crimped onto the single wire seal 16 (even though, this is not shown on the figures). The single wire seal 16 is configured for providing a sealing barrier between the cavity 9 and an external insulating sheath 17 of the grounding cable 15. The grounding cable 15 is intended to be connected to the ground of a vehicle. The use of a grounding terminal 8 improves the electrical connection between the common grounding plate 18 and the grounding cable 15.
As shown on figures 2 and 3, the common grounding plate 18 is mounted into the housing 4. For example, the common grounding plate 18 comprises fixing means 19. For example, the fixing means 19 have a fishbone shape, each secured, hooked, in a respective slot made in the housing 4, thereby attaching the common grounding plate 18 in the housing 4. The common grounding plate 18 comprises a plurality of openings 20, 21: in this example, four first openings 20 in which a ferrule 14 is inserted and one second opening 21 in which the grounding terminal 8 is inserted. The four first openings 20 are each respectively surrounded by at least one first flexible (i.e elastic) tongues 22 (in this example twelve first flexible tongues 22) (see Figure 4).
Two second flexible (i.e, elastic) tongue 23 extend from the edge of the second opening 21 (see Figures 4 to 9). The first flexible tongues 22 and the second flexible tongues 23 are bent so as to extend, in an insertion direction I of the shielded cables 10 and the grounding cable 15, from the common grounding plate 18 to a free end. This orientation of the first flexible tongues 22 and the second flexible tongues 23 allows for an easy insertion of the ferrules 14 and the grounding terminal 8, respectively in the first openings 20 and the second openings 21. The free ends of the first flexible tongues 22 and the second flexible tongues 23 are configured so as to establish an electrical contact between the common grounding plate 18, the ferrules 14 and the grounding terminal 8. In other words, the ferrules 14 and the grounding terminal 8 are electrically connected to each other through the common grounding plate 18. The first flexible tongues 22 and the second flexible tongues 23 maintain a resilient electrical contact between respectively the ferrules 14 and the grounding terminal 8.
The formation and bending of the second flexible tongues 23 are more particularly described in relation to Figures 5 to 8.
As shown in Figure 5, a second opening 21 is stamped in the sheet metal used for creating the grounding plate 18 (the first 20 and second 21 openings are possibly cut at the same time). In this embodiment example, the grounding plate is 0.3 millimetre thick (see the thickness TH in Figure 6). In this embodiment example, the second opening 21 extends over a surface of less than 16 square millimetres (this surface is shown in Figure 5 as being delimited by a dotted line). This surface is defined as the smallest rectangular or square shape including the second opening 21. For example, this surface has a square shape of less than 4 by 4 millimetres. Such small dimensions limit or cancel electromagnetic leakages. The second opening 21 comprises a slot 26 parallel to a longitudinal direction LD and one triangular cut-out 27 at each end of the slot 26. The slot 26 and triangular cut-outs 27 form a second opening 21 having a H-shape.
Such a cut-out results in the creation of two second flexible tongues 23 as illustrated in Figures 5 and 6. In this embodiment example, the slot 26 has a transversal width TW of 0.3 millimetre and a length LL of 1.6 millimetre. The transversal width TW has advantageously the minimum value compatible with the stamping tool, the thickness TH of the grounding plate 18 and the grounding plate 18 material. The two second flexible tongues 23 face each other. They have the same length. The length at the tip of each two second flexible tongue 23 is equal or greater than the corresponding width of the grounding terminal 8. In other words, each second flexible tongue 23 is configured so as to be in contact with the grounding terminal 8 over the full width of the grounding terminal 8.
At a next step, the second flexible tongues 23 are each bent so as to form in each flexible tongue, two different bending zones. Such a bending step can actually be made in more than one operation and with more than one tool. Each bending zone is curved around a line parallel to the longitudinal direction LD.
For each second flexible tongue 23, the two different bending zones are formed respectively as a proximal bending zone 28 and a distal bending zone 29. The proximal bending zone 28 is configured to provide a smooth surface in contact with the grounding terminal 8. In other words, the curvature radius of the proximal bending zone 28 is chosen so that this contact surface be appropriate for making an electrical contact with the grounding terminal 8. Indeed, after stamping the edges of the opening are sharp and not plated. Therefore, smoothing the surface configured to be in contact with the grounding terminal 8 is advantageous. As shown in Figure 9, the sharp edges are not in contact with the contact surface of the grounding terminal. The distal bending zone 29 is configured to flex when the grounding terminal 8 is inserted into the second opening 21 (see Figure 9). The curvature radius of the proximal bending zone 28 and distal bending zone 29 are optimized so as to reduce the gap between the second flexible tongues 23 and to have an appropriate contact force on the grounding terminal 8 and a good retention of the grounding terminal 8 in the second opening 21. Typically, the curvature radius of the proximal bending zone 28 and distal bending zone 29 are comprised between 0.1 and 0.2 millimetre. Such curvature radii also provide a good repeatability. The common seal 24 is configured for providing a sealing barrier between the seal retainer 5 and the outer sheath 11 of each shielded cable 10, and between the seal retainer 5 and the housing 4. The common seal 24 is advantageously mounted in the seal retainer 5.
For assembling the various elements of the electrical connector 2, one can implement for example the following steps.
On the one hand, the common grounding plate 18 is mounted in the housing 4 (in particular with the insertion of the fixing means 19 in corresponding housing slots).
On the other hand, the free ends of the shielded cables 10 are passed through passages 25 made through the rear face of the seal retainer 5 and through the common seal 24. The terminals 7 can be attached to the respective free end of each shielded cable 10 either before or after the shielded cables 10 are passed through the passages 25. The ferrules 14 are placed on the shielded cables 10 and connected to the cable shield either before or after the terminals 7 are attached to the shielded cables 10 (but after the shielded cables 10 are passed through the passages 25). Further, the grounding terminal 8 and the single wire seal 16 are placed and mounted on the free end of the grounding cable 15. Then, the grounding terminal 8 is inserted in the cavity 9 of the seal retainer 5. An assembly is thus obtained comprising the seal retainer 5, the common seal 24, the single wire seal 16 and the free ends of the shielded cables 10 and the grounding cable 15, respectively with the ferrules 14 and terminals 7 on the one hand, and the grounding terminal 8, on the other hand.
This assembly can then be mounted in the housing 4 in inserting, in the insertion direction I, the free ends of the shielded cables 10 with the ferrules 14 as well as the grounding terminal 8, respectively into the first opening 20 and the second openings 21 of the common grounding plate 18. Thereby, the common grounding plate 18 is connected to the cable shields (via each ferrule 14) and to the grounding cable 15 (via the grounding terminal 8). The seal retainer 5 is clipped onto the rear face of the housing 4.

Claims

An electrical connector (2) comprising:
- a plurality of power terminals (7) each respectively electrically connected to a shielded cable (10) comprising a cable shield surrounding a core (13) formed of at least one electrical wire,

- an insulating housing (4) having a plurality of compartments (6) configured for accommodating said power terminals (7),

- a grounding cable (15) having a free end located in said housing (4), a grounding terminal (8) being electrically connected to the free end of the grounding cable (15),

- a common grounding plate (18) electrically connected both to the cable shields of at least two shielded cables (10) and to said grounding terminal (8), the grounding plate (18) having an opening (21) extending in a longitudinal direction (LD) with at least two electrical flexible tongues (23), each flexible tongue (23) running at least partially along a respective side of the opening (21), parallel to the longitudinal direction (LD), and each flexible tongue (23) being configured to establish an electrical contact with the grounding terminal (8),
Characterized in that each flexible tongue (23) has two different bending zones (28, 29), each around a line parallel to the longitudinal direction (LD).
The electrical connector (2) according to claim 1, wherein the two different bending zones (28, 29) of each flexible tongue (23) comprise a proximal bending zone (28) configured to provide a smooth surface in contact with the grounding terminal (8), and a distal bending zone (29) configured to flex when the grounding terminal (8) is inserted into the opening (21).
The electrical connector (2) according to claim 2, wherein the proximal bending zone (28) and distal bending zone (29) respectively have a radius of curvature comprised between 0.1 and 0.2 millimetre.
The electrical connector (2) according to any preceding claim, wherein the opening (21) extends over a surface of less than 16 square millimetres.
The electrical connector (2) according to any preceding claim, wherein the grounding plate (18) has a thickness comprised between 0.2 and 0.3 millimetre, at least at the edge of the opening (21).
The electrical connector (2) according to any preceding claim, wherein the opening (21) comprises a slot (26) parallel to the longitudinal direction (LD) and a triangular cut-out (27) at each end of the slot (26).
The electrical connector (2) according to claim 6, wherein the slot (26) has a length (LL) in the longitudinal direction (LD) equal to or greater than the dimension parallel to the longitudinal direction (LD), of the contact surface of the grounding terminal (8) with each flexible tongue (23).
A method for manufacturing a grounding plate (18) for an electrical connector (2), comprising the step of stamping an opening (21) in a sheet metal extending in a longitudinal direction (LD), so as to form at least two electrical flexible tongues (23) running, each respectively at least partially along a respective side of the opening (21), parallel to the longitudinal direction (LD),
characterized in that it further comprises a step of forming, in each flexible tongue (23), two different bending zones (28, 29), each around a line parallel to the longitudinal direction (LD).