A Direct Plug Connector For An ECU

Field of the invention:

[0001 ] The present invention relates to a direct plug connector coupling a wiring harness to an Electronic Control Unit (ECU) and particularly relates to preventing failure of the ECU from water entry.

Background of the invention:

[0002] Water due to rain or pressure jet wash, lands on contact pads of the ECU and copper traces of a Printed Circuit Board (PCB) of the ECU, through multi-strand cable of wiring harness (WH) of vehicles. The multi-strand cable connects unsealed connector/splices/other joints, which is the reason/source of water entry in various applications (e.g. ignition, battery supply, starter motor, lights, etc.) of the vehicle. The water travels in the interstitial voids among multi-strand cable by both gravity and capillary action and lands on the exposed (e.g. unmolded or non-encapsulated) part of the PCB. The presence of water, which acts as electrolyte, on contact pads of the PCB and potential difference (voltage) between supply contact pad and adjacent (e.g. ground) contact pad or electrical vias, triggers electro-chemical corrosion. The electro-chemical corrosion corrodes the copper traces that connects to the rest of the circuit of PCB leading to an open circuit. Then, it is not possible to start the vehicle due to breakage in power supply to the control circuit of the ECU. The ECU with Direct Connection System (DCS) or Direct Plug Connector (DPS) is more vulnerable due to exposure of PCB to fluid media, not just in vehicles but also in other electronic appliances.

[0003] Hence, there is a need to prevent media (e.g. water) ingression into the ECU through multi-strand cable of wiring harness and subsequent event of electro-chemical corrosion. Brief description of the accompanying drawings:

[0004] An embodiment of the disclosure is described with reference to the following accompanying drawings,

[0005] Fig. 1 illustrates a schematic of a direct plug connector with a first connection, according to embodiment of the present invention;

[0006] Fig. 2 illustrates the direct plug connector with a second connection, according to an embodiment of the present invention;

[0007] Fig. 3 illustrates the direct plug connector with a third connection, according to an embodiment of the present invention;

[0008] Fig. 4 illustrates the direct plug connector with a fourth connection, according to an embodiment of the present invention, and

[0009] Fig. 5 illustrates the direct plug connector with a fifth connection, according to an embodiment of the present invention.

Detailed description of the embodiments:

[0010] Fig. 1 illustrates a schematic of a direct plug connector with a first connection, according to an embodiment of the present invention. The direct plug connector 108 is provided for an Electronic Control Unit (ECU) 102. The direct plug connector 108 can be used in vehicles comprising two-wheeler, a three-wheeler, four-wheeler and other types of vehicles or in appliances such as washing machine, refrigerator and the like. The ECU 102 comprises a Printed Circuit Board (PCB) 104 with contact pads 120. The direct plug connector 108 comprises an end cover 112. The end cover 112 is an integrated part of the direct plug connector 108. The end cover 112 houses a flexible member 118, such as a rubber gasket, having holes for each of a plurality of cables 116. The flexible member 118 also functions as a seal. A plurality of contact terminals 110 are arranged through the end cover 112. Only one contact terminal 110 is shown in the Fig. 1 for simplicity and clarity of explanation and must not be understood in limiting sense. The plurality of contact terminals 110 makes contact with the contact pads 120 of the ECU 102. A plurality of cables 116 are connected to the plurality of contact terminals 110 with respective stripped ends. Only one cable 116 is shown for the same reason of simplicity and clarity of explanation and therefore must not be understood in limiting manner. The plurality of cables 116 comprises multi-strand wires. The direct plug connector 108 is characterized by, an insulating material sealing a connection between the plurality of contact terminals 110 and the stripped ends of the plurality of cables 116. Hereinafter, the plurality of contact terminals 110 will be referred to as contact terminals 110 and the plurality of cables 116 will be referred to as cables 116.

[0011] The contact terminals 110 are joined to the respective cables 116, by crimping or by other means known in the art. The crimping is done on the insulation of the cables 116 and on the stripped ends of the cables 116. Alternatively, the crimping is done only on the stripped ends of the cables 116. Each of the contact terminals 110 are connected to respective cables 116.

[0012] The ECU 102 comprises different components 106 such as Random Access Memory (RAM), Input/output (I/O) interface, Buses, Analog-to-Digital Converter (ADC), Digital-to-Analog Converter (DAC), microprocessor and the like.

[0013] The insulating material is selected from a group comprising a potting material 114, a gel and a heat shrink tube 304 shown in Fig. 3. The potting material 114 or the gel comprises hydrophobic properties and completely seals when applied over the connection between the contact terminals 110 and the cables 116. In one embodiment, the contact terminals 110 are elongated to extend out of the flexible member 118, and the connection is sealed outside the flexible member 118 inside the end cover 112.

[0014] The existing contact terminals 110 are extended beyond the flexible member 118. The extension enables the joint or connection between the contact terminals 110 and the cables 116 comprising multi-strand wires. The connection is inside the available cavity of the end cover 112 of the direct plug connector 108, which is filled with potting material 114. The potting material 114 prevents water flow in the cables 116 into the ECU 102 beyond the sealed connection. The stripped ends of the cables 116 are in contact with the contact terminals 110 until a specific length and not the entire length.

[0015] A portion of the contact terminals 110 till which the stripped ends of the cables 116 reach, lies outside the flexible member 118. The remaining portion towards the contact pads 120 is elongated, i.e. increased in length. The flexible member 118 also helps to prevent the potting material 114 or gel to flow onto the PCB 104. The potting material 114 is poured around the extended contact terminals 110 filling the end cover 112, and seals the vulnerable portions of the contact terminals 110, thus preventing water to travel onto the contact pads 120 of the ECU 102.

[0016] Fig. 2 illustrates the direct plug connector with a second connection, according to an embodiment of the present invention. The second connection comprises plurality of bridge terminals 210 connecting the stripped ends of the cables 116 to the respective contact terminals 110. Further, the plurality of bridge terminals 210 are connected to the contact terminals 110 through a multi- strand auxiliary cable 202. The plurality of bridge terminals 210 will hereinafter be are referred to as bridge terminals 210.

[0017] The bridge terminals 210 are additional terminals, which are introduced between the contact terminals 110 and the cables 116. Each of the contact terminals 110 is connected or joined with a multi-strand auxiliary cable 202 to one end of the corresponding bridge terminals 210. The other end of bridge terminals 210 is attached to the cables 116 of a wiring harness. The insulating material 114 is filled inside the end cover 112 and around the bridge terminals 210 to completely prevent water from passing through the joint or second connection. As per second connection, water path is halted at the bridge terminals 210 with no further propagation into the ECU 102.

[0018] The bridge terminals 210 are either similar to or different from the contact terminals 110. Both of the bridge terminals 210 and the contact terminals 110 are formed as single piece or combination of two or more pieces of material which are good conductor of electricity.

[0019] Fig. 3 illustrates the direct plug connector with a third connection, according to an embodiment of the present invention. The third connection comprises bridge terminals 210 connected to respective contact terminals 110 through a single-strand auxiliary cable 302. The bridge terminals 210 are additional terminals, which are introduced between the contact terminals 110 and the cables 116. The other end of the bridge terminals 210 are attached/connected to cables 116 of the wiring harness comprising multi-strand wires. The bridge terminals 210 are covered with respective number of heat shrink tubes 304 /sleeves to seal the joint. The heat shrink tubes 304 prevents water to travel beyond the joint into the ECU 102. The single-strand auxiliary cable 302 is crimped with insulation at both contact terminals 110 and at the bridge terminals 210. Further, heating the contact terminals 110 and the bridge terminals 210 ensures tight crimping for the cables 116 with insulation. With the third connection, water path is halted at bridge terminals 210 with no further propagation into the ECU 102. Further, the single-strand auxiliary cable 302 between the contact terminals 110 and the bridge terminals 210 does not allow water flow through capillary action.

[0020] In other embodiment in the third connection, instead of heat shrink tubes 304, the potting material 114 or gel is used as insulating material. In yet another embodiment, both of the heat shrink tubes 304 and the potting material 114 or gel are applied over the connection.

[0021] Fig. 4 illustrates the direct plug connector with a fourth connection, according to an embodiment of the present invention. The fourth connection is exactly similar to the third connection but a gasket 402 is provided between the bridge terminals 210 and the contact terminals 110. The gasket 402 is arranged around the single-strand auxiliary cable 302. The gasket 402 along with the single-strand auxiliary cable 302 is joined at the bridge terminals 210 to reinforce the connection further to prevent water travel into ECU 102.

[0022] Fig. 5 illustrates the direct plug connector with a fifth connection, according to an embodiment of the present invention. The fifth connection is exactly similar to the third connection comprising the bridge terminals 210 connected to respective contact terminals 110, but through a multi-strand anti-capillary cable 502. The other end of the bridge terminals 210 are connected to cables 116. The anti-capillary cable 502 does not allow water to travel inside it. The plurality of bridge terminals 210 are optionally sealed using the insulating material such as heat shrink tubes 304.

[0023] In all the connection disclosed from Fig. 1 through Fig. 5, the size of the housing of direct plug connector 108, the ECU 102 and other components are shown relatively bigger only for the clear understanding and illustration. The actual size during implementation is different and varies as per the design requirement.

[0024] In accordance to an embodiment of the present invention, water path in the multi- strand cables 116 is broken or made dis-continuous by introduction of an intermediate joint/connection before the flexible member 118 in the end cover 112 of the direct plug connector 108, along with multitude combination of joining methodology of upstream and downstream part of the cables 116 of the wiring harness. The contact terminals 1 10 are extended or the bridge terminals 210 are introduced in the connection. In case of bridge terminals 210, upstream and downstream part of the cables 116 are connected to the bridge terminals 210. The water path in the cables 116 is made discontinuous. The water is does not travel into the ECU 102 beyond the connections. Hence, electrochemical corrosion of PCB 104 is prevented. The bridge terminals 210 or connections before the housing of the direct plug connector 108 can be a maintainable system wherein upstream cable 116 can be replaced if aged over a period of time due to presence of water inside it. The present invention provides a concept against capillary water entry in wiring harness cables 116 of ECU 102. The present invention provides an anti-ingression wiring harness for electronic control unit (ECU) 102.

[0025] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.