Electromagnetic interference (EMI) protection method for a connector assembly using a conductive seal

Description

BACKGROUND OF THE INVENTION

[0001] Electromagnetic interference (EMI) affects an electrical circuit due to a disturbance, from a source, by electromagnetic induction, electrostatic coupling or conduction. EMI may degrade the performance of a circuit or may even stop it from functioning. In the case where the circuit includes a data path, EMI may affect the effectiveness of the data path due to an increase in error rate to the total loss of the data. A source that may generate changing electrical currents and voltage that may cause EMI may include, for example, automotive injection systems, mobile phone cellular network, or the like. It is thus essential to manage the generation of EMI to avoid the detrimental effects caused by it; and to consequently maximize the effectiveness of an electrical circuit that may otherwise be vulnerable to the detrimental effects of EMI.

[0002] Ways to avoid or reduce the detrimental effects of EMI include conduction, shielding, or the like. EMI protection by conduction is achieved by the conduction of EMI between conductive elements or conductors that are in physical contact, while EMI protection by shielding is achieved by shielding radiated EMI by induction (i.e., the absence of physical contacts of conductors). In a connector assembly, conducted EMI is directed through a path of adjoining conductive elements or conductors and towards a device onto which the connector assembly is mounted.

[0003] US 9 431 771 B1 is the closest prior art to the invention and refers to an electromagnetically shielded connector system including a first and second connector. The first connector further includes a first terminal and a first electromagnetic shield surrounding the first terminal. The first shield defines a flexible interface contact projecting from an end of the first shield. The second connector further includes a second terminal configured to mate with the first terminal and a second electromagnetic shield surrounding the second terminal. The second shield is configured to be electrically connected with the first shield at least via the flexible interface contact. The second shield is surrounded by a supporting member. At least a portion of an outer surface of the second shield is in intimate contact with the supporting member. The second shield is configured to be disposed intermediate the interface contact and the supporting member. The interface contact is formed and configured to exert a normal spring force on the second shield. US 4 886 463 A discloses an electrical connector apparatus that includes an electromagnetic interference seal means comprising a flexible, generally annular, conductive member, wherein the electromagnetic interference seal means slideably interfitting and being fixedly connected to said male shell portion or said female shell portion during said electrical connector apparatus operation. US 2002 / 0442228 A1 shows a shielded connector that comprises a first connector having a first inner housing for receiving a first terminal connected to a shielded wire and an electrically conductive shielding shell, which is coated on the outer circumference of the first inner housing and connected to a shielded part of the shielded wire; and a second connector having an electrically conductive shielded terminal resiliently coming in contact with the outer circumference of the shielding shell, an electrically conductive outer housing coming in contact with the shielded terminal for receiving the shielded terminal, a second inner housing inserted in the outer housing, a second terminal inserted in the second inner housing, and an electrically conductive connecting member, which is integrally formed with the outer housing and fixed on a connector-mounting wall of ground side with fixing means. US 2009 / 149048 A1 discloses a high voltage electrical connector that includes a connector body. A first connector is supported within the connector body. A second connector is supported within the connector body and electrically connected to the first connector. A high voltage circuit protection device is electrically connected between the first connector and the second connector.SUMMARY OF THE INVENTION

[0004] It is an object of the invention to provide an improved method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to a connector assembly having a conductive seal, a female connector assembly, and a male connector assembly. This object is achieved by a method according to claim 1. Further features and advantageous modifications are shown in the dependent claims.

[0005] The invention is directed to a method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to a connector assembly having a conductive seal, a female connector assembly, and a male connector assembly. The method of this invention for reducing the effect of the EMI in the connector assembly includes the steps of: conducting the EMI, generated by at least a wire housed within the female connector assembly, to a corresponding wire shielding that respectively surrounds the wire and to a corresponding crimped ferrule that surrounds the wire shielding; conducting the EMI to a corresponding silicone back seal that respectively directly contacts the crimped ferrule, the silicone back seal being housed within and directly contacting at least a portion of a female outer housing of said female connector assembly, wherein said conductive silicone back seal is inserted inside a back portion of said female outer housing; conducting the EMI to the female connector assembly, the female connector assembly having a portion thereof being in contact with another silicone seal, the another silicone seal being located between and in direct contact with the portion of the female connector assembly and a portion of a male outer housing of the male connector assembly, wherein said another conductive silicone seal is disposed between and in direct contact with said portion of said male outer housing and an extending member of said female outer housing, wherein said another conductive silicone seal surrounds said extending member, wherein said portion of said male outer housing surrounds said another conductive silicone seal. The method of this invention for reducing the effect of the EMI in the connector assembly further includes the steps of: conducting the EMI to the portion of the male connector assembly that surrounds and contacts the another silicone seal, the EMI being further conducted to the male connector assembly and towards a flange of the male connector assembly, the flange accommodating at least a limiter that in turn accommodates therein a respective bolt that connects or mounts the connector assembly to a device, wherein exposed sides of said flange are surrounded in their entireties by a non-conductive over-molded seal. The method of this invention for reducing the effect of the EMI in the connector assembly additionally includes the steps of: conducting the EMI from the flange member of the male connector assembly to the limiter, which surrounds and contacts said bolt, and to the corresponding bolt, and subsequently, conducting the EMI through the bolt and ultimately to the device.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1A is a cross-sectional view of a connector assembly showing various elements that make up a female connector assembly and a male connector assembly of the connector assembly; FIG. 1B is a cross-sectional view, which is a continuation of the view shown in FIG. 1A to complete the connector assembly, showing in more detail a device onto which the connector assembly is connected or mounted; FIG. 2A is the cross-sectional view of the connector assembly, as in FIG. 1A, further showing a path through which EMI is conducted from a wire shielding through various conductive elements inside the connector assembly and towards a housing of an associated device onto which the connector assembly is connected or mounted; FIG. 2B is the cross-sectional view of the continuation of the view shown in FIG. 1B to complete the connector assembly, as in FIG. 1B, further showing in more detail the path through which the EMI is conducted from the connector assembly to the device onto which the connector assembly is connected or mounted; and FIG. 3 is a flowchart of the path through which the EMI is conducted from the wire shielding through various conductive elements inside the connector assembly towards a housing of the associated device onto which the conductor assembly is connected or mounted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The connector assembly, generally referred to as reference number 1 in FIG. 1A and FIG. 1B, includes a female connector assembly 3 and a male connector assembly 5, the female connector assembly 3 and the male connector assembly 5 being coupled together, and FIG. 1B being a continuation of FIG. 1A to complete the connector assembly 1. The connector assembly 1 is preferably a high voltage connector assembly for housing therein high voltage wires 10 with respective wire shieldings 13. Surrounding each of the wire shieldings 13 is a corresponding crimped ferrule 15; and surrounding the crimpled ferrule 15 and the corresponding wire shielding 13 is a corresponding electrically conductive silicone back seal 18 inserted inside a back portion 20 of a female outer housing 25 of the female connector assembly 3.

[0008] The wire shielding 13 is made of metal, a conductive material, or the like. The crimped ferrule 15 is made of metal (e.g., copper, stainless steel, or the like). The electrically conductive silicone back seal 18 is made of an electrically conductive metal-infused silicone or the like. The female outer housing 25 is made of a metal-infused conductive plastic, resin, nylon, or the like. The female outer housing 25 may also be made of a stainless steel fiber-filled plastic, resin, nylon or the like.

[0009] The back portion 20 of the female outer housing 25 includes a back opening 28 for containing therein at least one of the high voltage wires 10 each surrounded by the corresponding wire shielding 13, which in turn is surrounded by the corresponding crimped ferrule 15 protected or sealed therearound by the corresponding electrically conductive silicone back seal 18.

[0010] Extending along a portion of the opening 28 is an extending member 30 extending from the back portion 20 of the female outer housing 25 of the female connector assembly 3 towards an opening 35 of a male outer housing 38 of the male connector assembly 5. A portion 42 of the male outer housing 38 surrounds an electrically conductive silicone ring seal 40 positioned between the extending member 30 of the female outer housing 25 and the male outer housing 38. The electrically conductive silicone ring seal 40 provides a seal between the extending member 30 of the female outer housing 25 and the male outer housing 38. The male outer housing 38 has, at end thereof away from the female connector assembly 3, a surrounding flange 45 (see also FIG. 1B, a continued illustration of the male connector assembly 5) extending therefrom.

[0011] The electrically conductive silicone ring seal 40 is made of a metal-infused silicone. The male outer housing 38 is made of a metal-infused conductive plastic, resin, nylon, or the like. The male outer housing 38 may also be made of a stainless steel fiber-filled plastic, resin, nylon, or the like.

[0012] Illustrated in either FIG. 1A or FIG. 1b is a non-conductive over-molded silicone seal 50, which surrounds exposed sides of the flange 45 (preferably the exposed sides in their entireties) of the male connector assembly 5. Although FIG. 1A shows the bolt heads 55 of the bolts 58 (made of stainless steel or the like), FIG. 1B more particularly illustrates the bolts 58 passing through apertures 60 that respectively pass through the flange 45 and the surrounding over-molded silicone seal 50. The bolts 58 have respective threads 65 for allowing the threaded bolts 58 to fasten the flange 45, surrounded by the over-molded silicone seal 50, to the device 70; and ultimately, the connector assembly 1 becomes mounted to the device 70.

[0013] Further illustrated in FIG. 1B are conductive compression limiters or rings 75 (made of aluminum or the like) respectively fitted inside the apertures 60, which in turn respectively accommodate therein the bodies 78 of the bolts 58, such that each conductive compression limiter or ring 75 rests between a corresponding one of the bolt body 78 and a corresponding side of the flange 45.

[0014] As further illustrated in FIG. 1B, the over-molded silicone seal 50 has a first set of pads 80, the pads 80 respectively resting inside indentations 85 beneath each head 55 of the corresponding bolt 58. The over-molded silicone seal 50 further has a second set of pads 90, the pads 90 respectively resting inside corresponding indentations 95 at an adjoining side 98 of the device 70.

[0015] The method for directing a conductive EMI through a path of conductive elements inside the connector assembly 1 is hereinafter described. The conductive EMI path is labeled in FIGS. 2A and 2B as a line arrow that extends beginning from a wire shielding 13 through the various conductive elements inside the connector assembly 1 and ultimately ending at the device 70.

[0016] As illustrated in FIG. 2A, the EMI generated by, e.g., the conducting high voltage wires 10 (or other source) is conducted to the corresponding wire shielding 13. The crimped ferrules 15 are in physical contact with and surrounding the corresponding wire shieldings 13; and thus, the EMI generated by, e.g., the wires 10 (or other source) is conducted to the corresponding wire shielding 13 and through the crimped ferrules 15. The crimped ferrules 15 are metallic and conductive, and preferably made of copper, stainless steel, or the like. The conducted EMI travels from the crimped ferrules 15 to the corresponding silicone back seals 18, each of the silicone back seals 18 being a metal-infused silicone back seal 18. From the silicone back seals 18, the conducted EMI further travels to the back portion 20 of the female outer housing 25. The conducted EMI is further conducted to the female outer housing 25 and to the electrically conducting silicone ring seals 40 that surround the extending member 30 that extends from the back portions 20 of the female outer housing 25, the silicone ring seal 40 being a metal-infused silicone ring seal 40. The conducted EMI then travels towards the portion 42 of the male outer housing 38 that surrounds the metal-infused silicone ring seals 40, and further travels through the male outer housing 38 towards the conductive compression limiters or rings 75 that respectively surround the corresponding bodies 78 of the bolts 58. The conducted EMI thus travels to the bolts 58, and is discharged to the device 70 (e.g., a compressor housing or the like), which is metallic.

[0017] FIG. 3 illustrates a flowchart of the conducted EMI flow path, the EMI flow path having just described in reference to FIGS. 2A and 2B. As shown in FIG. 3, in Step S1, the EMI is generated by the high voltage wires 10 and conducted to the corresponding wire shielding 13. The crimped ferrules 15 are in physical contact with and surround the corresponding wire shieldings 13; and thus, in Step S2, the EMI generated from the wires 10 is conducted to the corresponding wire shielding 13 and through the crimped ferrules 15. In Step S3, the conducted EMI travels from the crimped ferrules 15 to the corresponding silicone back seals 18. From the silicone back seals 18, the conducted EMI in Step S4 further travels to the back portion 20 of the female outer housing 25.

[0018] Further shown in FIG. 3, the conducted EMI is further conducted to the female outer housing 25 and, in Step S5, to the electrically conducting silicone ring seals 40 that surround the extending member 30 that extends from the back portions 20 of the female outer housing 25. In Step S6, the conducted EMI then travels towards the portion 42 of the male outer housing 38 that surrounds the metal-infused silicone ring seals 40, and further travels through the male outer housing 38 towards the conductive compression limiters or rings 75 (in Step S7) that respectively surround the corresponding bodies 78 of the bolts 58. The conducted EMI thus travels to the bolts 58 (in Step S8), and is discharged to the device 70 (in Step S9).

Claims

1. A method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to a connector assembly (1) having at least one electrically conductive seal (18, 40), a female connector assembly (3), and a male connector assembly (5), said method comprising the steps of: conducting said EMI, generated by at least a wire (10) housed within said female connector assembly, to a corresponding wire shielding (13) that respectively surrounds said wire and to a corresponding crimped ferrule (15) that surrounds said wire shielding (13); conducting said EMI to a corresponding electrically conductive silicone back seal (18) that respectively directly contacts said crimped ferrule (15), said electrically conductive silicone back seal being housed within and directly contacting at least a portion of a female outer housing (25) of said female connector assembly (3), wherein said conductive silicone back seal (18) is inserted inside a back portion (20) of said female outer housing (25); conducting said EMI to said female connector assembly (3), said female connector assembly (3) having a portion thereof being in contact with another electrically conductive silicone seal (40), said another electrically conductive silicone seal being located between and in direct contact with said portion of said female connector assembly (3) and a portion (42) of a male outer housing (38) of said male connector assembly (5), wherein said another conductive silicone seal (40) is disposed between and in direct contact with said portion (42) of said male outer housing (38) and an extending member (30) of said female outer housing (25), wherein said another conductive silicone seal (40) surrounds said extending member (30), wherein said portion (42) of said male outer housing (38) surrounds said another conductive silicone seal (40); conducting said EMI to said portion of said male connector assembly (5) that surrounds and contacts said another electrically conductive silicone seal (40), said EMI being further conducted to said male connector assembly (5) and towards a flange (45) of said male connector assembly (5), said flange accommodating at least a limiter (75) that in turn accommodates therein a respective bolt (58) that connects or mounts said connector assembly to a device (70), wherein exposed sides of said flange (45) are surrounded in their entireties by a non-conductive over-molded seal (50); conducting said EMI from said flange to said limiter (75) and to said bolt (58) that surrounds and contacts thereto, and subsequently, conducting said EMI through said bolt (58) and to said device (70) onto which said connector assembly (1) is connected or mounted.

2. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said terminal is a high voltage terminal.

3. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said crimped ferrule is made of metal selected from the group consisting of copper and stainless steel.

4. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said electrically conductive silicone back seal is a metal-infused electrically conductive silicone back seal.

5. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said female outer housing (25) is made of a metal-infused conductive plastic, resin, nylon or the like.

6. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 4, characterized in that said another electrically conductive silicone seal, which is located between and in contact with said portion of said female connector assembly (3) and said portion of said male connector assembly (5), is a metal-infused electrically conductive silicone seal.

7. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said male outer housing (38) is made of metal-infused conductive plastic, resin, nylon or the like.

8. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said limiter is one of a compression limiter and a compression ring housed within said flange of said male outer housing (38), one of said compression limiter and said compression ring accommodates therein said respective bolt that connects or mounts said connector assembly to said device.

9. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that one of a compression limiter and a compression ring is made of metal selected from the group consisting of aluminum, and stainless steel.

10. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said bolt is made of stainless steel.

11. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that said device is a compressor.

12. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 11, characterized in that a housing of said compressor is made of metal.

13. The method for reducing the effect of electromagnetic interference (EMI) to provide EMI protection to said connector assembly (1) according to claim 1, characterized in that at least one of said female outer housing (25) and said male outer housing (38) is made of a stainless steel fiber-filled plastic, resin, nylon, or the like.