AU2003270998A1 - Assembly for an electronic control unit - Google Patents

Description

Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

(ORIGINAL)

Name of Applicant(s): Actual Inventor(s): Address for Service: Invention Title: The following statement is performing it known to us.

Robert Bosch GmbH, of Postfach 30 02 20, D-70442 Stuttgart, Germany DAVIES COLLISON CAVE, Patent Attorneys, of 1 Nicholson Street, Melbourne, Victoria 3000, Australia "Assembly for an electronic control unit" a full description of this invention, including the best method of Q:NOPERXSSB\2003\Decmber 63\12261950 complete. 3S0.doc 17/12/03 P:'oparssb\12261950 emplacspec.dow-17/12/03 -1- ASSEMBLY FOR AN ELECTRONIC CONTROL UNIT FIELD OF THE INVENTION The present invention relates to an assembly for an electronic control unit (ECU), in particular for automobiles. More particularly, the invention relates to an ECU and pinheader assembly for connecting a wiring harness to an electronic control unit.

BACKGROUND OF THE INVENTION Electronic control units (ECUs) commonly used in body computers in automotive applications include a printed circuit board (PCB) within a housing and some form of connector for interconnecting the ECU with other electronic functions of the automobile.

In the applicant's experience, it can be difficult to ensure that the connector is properly aligned with the PCB and also with the housing. If the connector is not properly aligned with the housing, there may be some tolerance-related tightness which stresses the PCB solder joints and may inconvenience the service technician. In more severe cases of misalignment, the connector may not receive the wiring harness at all.

In an earlier ECU arrangement by the applicant, two alignment points were used to align.

the PCB to the ECU housing. This arrangement did not consistently ensure alignment of the connector with the housing and when one alignment tolerance was exceeded, this sometimes compounded with other alignment tolerances to misalign the connector with the housing.

It is desired to provide a more robust form of alignment, giving rise to fewer problems of alignment between the connector, the PCB and the housing.

P:opessb\12261930 cmplete sp.dmx-l'7l/2/3 -2- The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

SUMMARY OF THE INVENTION The present invention provides an assembly for an electronic control unit (ECU) including a housing, a printed circuit board (PCB) within the housing, a connector for connecting a wiring harness to the ECU and a pin-header mounted to the PCB by first alignment means, characterised in that the pin-header includes second alignment means for aligning the pinheader with guide walls of the housing.

Preferably, the housing includes a base part having an expander stud and a top part having an expander sleeve and the second alignment means includes an alignment hole in the pinheader assembly receiving the expander sleeve therein. The expander sleeve is arranged to receive therein the expander stud in such a manner that walls of the expander sleeve are expanded by receiving the expander stud to thereby create an interference fit of the expander sleeve in the alignment hole. Alternatively, the second alignment means may include an alignment pin received in pin-receiving holes on the housing.

Preferably, the assembly further includes third alignment means for aligning the PCB with the housing. This third alignment means may take the form of an alignment hole in the PCB, together with cooperating stud and expander formations on the housing for engaging the PCB alignment hole.

Preferably, the pin-header includes an extended portion and the alignment hole is positioned in the extended portion. A plane of the extended portion may be separated from but substantially parallel with a plane of the body of the pin-header. Preferably, the extended portion and the body of the pin-header assembly are connected by a neck portion extending therebetween.

P'opassb\12261950 cmplee spec.doc-17/1203 -3- Preferably, the connector includes guide means extending internally or externally or both relative to the housing for guiding connection of the wiring harness to the pin-header.

Preferably, the guide means includes interlocking means for interlocking engagement of the guide means with the wiring harness. Preferably, the connector includes an o-ring or other sealing and cushioning means at the bottom of the guide means where the guide.

means contacts the body of the pin-header.

Preferably, the housing is formed of moulded plastic in two interlocking parts.

In one embodiment, the assembly includes two pin-headers connected to each other by a header connector piece. These two pin-headers may be employed together in relation to the same PCB but may form part of different connectors on the same housing.

Advantageously, the pin-headers may be manufactured as a dual header assembly, whereby both pin-headers may be used with a single ECU or the pin-headers may be broken apart at the header connector piece for separate use thereof.

The present invention also provides a pin-header for a connector assembly of an automotive electronic control unit having a printed circuit board (PCB), the pin-header having first alignment means for mounting the pin-header to the PCB, characterised in that the pin-header includes second alignment means for aligning the pin-header with guide walls of a housing of the electronic control unit.

Preferably, the pin-header in one embodiment includes two pin-header bodies connected to each other by a header connector piece, each pin-header body accommodating a plurality of connection pins for engaging the PCB and for cooperating, as part of said connector assembly, with a wiring harness.

In one embodiment, the pin-header includes a plurality of pins forming part of the connector. In an alternative embodiment, the pin-header includes a plurality of pin receiving holes instead of the pins to accommodate a wiring harness connector having pins thereon instead of receiving holes.

P'opcAsb\l22619 copid sWp.doc-17/12/03 -4- Advantageously, the separate first and second alignment means are used to align and connect the pin-header with the PCB and independently with the housing. This allows for a robust means of ensuring alignment of the pin-header (as part of the connector) with the housing. The improved alignment is advantageously more favourable with respect to manufacturing tolerances and reduces rattling in vibration tests.

Further features of embodiments of the invention are described hereinafter, by way of example only, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS :Figure 1 is a perspective view of a PCB having dual pin-headers positioned thereon; Figure 2 is a perspective view of a base part of an ECU housing Figure 3 is a perspective view of an outside face of a top part of the ECU housing; Figure 4 is a perspective view of the underside of the top part of the ECU housing; Figure 5 is a partial side cross-sectional view of an ECU assembly, showing the location of the pin-header relative to the PCB and top and base parts of the housing; and Figures 6A 6B are side and plan views respectively of dual pin-headers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to Figures 1 to 5, 6A and 6B, embodiments of the invention relate to an electronic control unit assembly (ECU) 10 having a printed circuit board (PCB) 12 enclosed and located therein. A housing of the ECU 10 is made primarily of two parts, a base (or back) part 14 which is adapted to receive a top (or front) part 16 in snap-fitting P:\opaewb\122695 complde spc.doc-17/12/03 connection to enclose PCB 12. Because of the relatively planar shape of PCB 12, housing base and top parts 14 and 16 are of a roughly similar planar configuration but with side walls adapted to fit together according to known snap fit interlocking arrangements.

In the top surface of top part 16, two rectangular holes are provided for receiving respective wiring harness connectors (not shown). These rectangular holes have walls 32, extending at right angles to the top surface, and wall guides 33, forming part of respective connectors 30. In one embodiment, the top part 16 has two such rectangular holes (as part of respective connectors 30), but in an alternative embodiment, only one such connector hole is provided in top part 16. Whether one connector is required or two connectors are required will depend on the design and function of the electronics housed within the ECU.

Each connector 30 is effectively made up of the connector walls 32 on housing top part 16, together with wall guides 33, interlocking protrusions 34 (for interlocking with corresponding formations on a wiring harness connector (not shown)) and connection pins 21 on pin-header 20. Connector walls 32, together with wall guides 33 and interlocking protrusions 34, extend, in one embodiment, substantially internally of the housing so as to engage a header body 27 in an appropriately aligned position so that the wiring harness connector slots appropriately match with the connection pins 21. In an alternative embodiment of connector 30, the connector walls 32, wall guides 33 and interlocking protrusions 34 may extend partially or mostly outwardly of the top part 16.

An o-ring (not shown) or similar form of sealing and cushioning material may be attached at the bottom of connector walls 32 so as to rest on an upper surface of header body 27 when the ECU 12 is assembled.

As shown in Figures 1, 5, 6A and 6B, pin-header 20 includes a plurality of connection pins 21 extending through a header body 27 so as to engage PCB 12 on an underside of the pinheader assembly 20. The engagement of connection pins 21 with corresponding holes in PCB 12 serves as one form of alignment between pin-header 20 and PCB 12. Connection pins 21 also extend upwardly within (and as part of) connector 30 for interconnection with P:'oparab\12261930 cmpte s*pe.doc17/1203 -6corresponding holes or slots in a wiring harness connector. The pin-header 20 includes header PCB clips 22 at opposite corners of header body 27 for clipping the pin-header to PCB 12 and thus aligning and connecting the pin-header 20 to PCB 12. Thus, header PCB clips 22 form one kind of alignment means within the whole ECU assembly Pin-header 20 has a header alignment plate 26 extending from one end thereof Header alignment plate 26 is on a plane roughly parallel to that of header body 27 but elevated relative thereto. The elevation of header alignment plate 26 relative to header body 27 is provided by a header neck 25 which is curved or ramped so as to connect header alignment plate 26 with header body 27. Header neck 25 is preferably integrally formed with header alignment plate 26 and has a header alignment hole 24 therein.

Header alignment hole 24 is arranged on PCB 12 (when pin-header assembly 20 is connected thereto) so as to be generally vertically aligned with a PCB stud hole 43 in PCB 12. Header alignment hole 24 is configured to receive expander sleeve 46 therethrough so as to engage stud 44 protruding from housing base part 14. During assembly of ECU the PCB 12 with pin-header assembly 20 connected thereto (by clips 22) is fitted generally into place on housing base part 14 and then housing top part 16 is fitted onto base part 14 over PCB 12. In this manner, prior to top part 16 being fitted over PCB 12, stud 44 extends through PCB stud hole 43 toward header alignment hole 24, but not so far as to actually pass within header alignment hole 24. Thus, when the expander sleeve 46 passes through header alignment hole 24 during fitment of top part 16 onto base part 14, expander sleeve 46 engages and passes around stud 44 to the position shown in Figure 5. The fit of stud 44 within expander sleeve 46 is such that, when expander sleeve 46 receives stud 44 therein, the walls of expander sleeve 46 are pushed apart or outwardly, thus forcing the walls of expander sleeve 46 to contact interior walls of header alignment hole 24 within header alignment plate 26.

The alignment and connection function of stud 44, expander sleeve 46 and header alignment hole 24 is advantageous in aligning and anchoring pin-header 20 within connector 30 and the housing. The interference fit of expander sleeve 46 with header P:opar\ssb\I2261950 complce sp.dx-17/12/03 -7alignment hole 24 created when top part 16 is fitted onto base part 14 assists in alignment as well as connection.

PCB stud hole 43 does not engage stud 44 in an alignment sense. Rather, PCB stud hole 43 is provided in order to allow stud 44 to pass therethrough without contacting PCB 12.

In an alternative form of alignment between pin-header 20 and the housing as described above, alternative engagement formations may be employed to achieve such alignment.

For example, instead of alignment hole 24, alignment plate 26 may have a pin extending vertically upwardly toward a pin receiving portion (such as a shortened version of expander sleeve 46) in housing top part 16 and downwardly towards another pin receiving portion on housing base part 14. This alternative form of alignment, and the form:of alignment described above in relation to Figure 5, may be augmented by providing further alignment formations on header body 27, such as a rim, edge or lip of a shape corresponding to the interior profile of connector walls 32. In this way, when connector walls 32 are fitted into place so that the lower extremity of those walls rests upon the surface of header body 27 around pins 21, the rim provided on header body 27 acts to guide connector walls 32 into an appropriate alignment. The rim may be provided with a sloped or bevelled edge around its outside in order to guide the inside edge of the bottom of connector walls 32 and thereby assist with such alignment as connector walls 32 are fitted to place on header body 27.

In considering the dual header arrangements shown in Figures 1, 6A and 6B, it should be noted that, while the pin-headers are formed identically, the alignment hole 24 is only used with respect to one of those headers, thus making the alignment hole, alignment plate and neck portions of the other pin-header redundant as the two pin-header bodies are connected by header connector piece 28 and thus alignment of one of the pin-headers 20 involves alignment of the other pin-header. Such redundancy will not occur, however, if the dual pin-headers are separated by breaking header connector piece 28. Header connector piece 28 has a breaking point manufactured therein about halfway between the two header bodies 27.

P:Nopcrub\s2261950 compae spctdx17/12/03 -8- In one embodiment, header alignment plate 26 is elevated relative to header body 27 in order to facilitate the form of alignment and connection provided by the interference fit of expander sleeve 46 within header alignment hole 24 when stud 44 is inserted therein. This kind of arrangement may be accomplished in an alternative embodiment wherein header alignment plate 26 is generally co-planar with header body 27, for example where the connector design involves connector walls 32 extending substantially outwardly of top plate 16 and the entire pin-header 20 and PCB 12 are located more toward top part 16 than base part 14. Importantly, header alignment hole 24 is used to align pin-header 20 with the housing, separately to any alignment of the PCB 12 with the housing or the pin-header with the PCB 12.

In an alternative embodiment of pin-header 20, connection pins 21 may be replaced with connection pin receiving holes for receiving corresponding pins on a wiring harness connector.

In an alternative embodiment of connector 30, connector walls 32 may be arranged so as to have wall guides 33 formed as slots therein, rather than as ribs or protrusions. In such an embodiment, interlocking protrusions 34 may be formed as recesses instead so as to receive corresponding protrusions on a wiring harness connector. Thus, while one embodiment of connector 30 is shown in the drawings, the present invention contemplates and includes an embodiment of connector 30 which is in essence a kinematic inversion thereof, in a form such as that described immediately above.

Alignment of PCB 12 with the housing is accomplished by means ofa PCB alignment hole 42 located toward one corner of the PCB 12, in combination with a base pin 40 formed on base part 14 and an expander slot or clip 41 formed on top part 16. When PCB 12 is fitted into base part 14, base pin 40 extends through PCB alignment hole 42. When housing top part 16 is fitted to base part 14 over PCB 12, expander slot 41 receives base pin 40 therein and the side walls of expander slot 41 are pushed apart by base pin 40 so as to engage PCB 12 around the walls of PCB alignment hole 42. This form of connection and alignment P:\opeec.b\122695O cmpidc tpcc.dc-I7II2I03 -9acts as another form of alignment, independent of the alignment of pin-header 20 with PCB 12 and the housing. Location of the PCB alignment hole 42 towards one corer of PCB 12 enables greater tolerance of movement of the PCB 12 to allow alignment of pinheader 20 within connector Apart from the conductive connection pins 21, all other components of ECU 10 are formed of a rigid moulded plastic.

List of reference numerals and description terms 10 ECU 12 PCB 14 housing back (base) part 16 housing front (top) part pin header 21 connection pins 22 header PCB clips 24 header alignment hole header neck 26 header alignment plate 27 header body 28 header connector piece connector 32 connector walls 33 wall guides 34 interlocking protrusions base pin 41 slot/clip/expander slot 42 PCB alignment hole 43 PCB stud hole 44 stud 46 expander sleeve

Claims (13)

1. An assembly (10) for an electronic control unit (ECU) including a housing (14, 16), a printed circuit board (PCB) (12) within the housing (14, 16), a connector (30) for connecting a wiring harness to the ECU and a pin-header (20) mounted to the PCB (12) by first alignment means (21, 22), characterised in that the pin-header (20) includes second alignment means (24) for aligning the pin-header (20) with guide walls (32) of the housing (16).

2. The assembly as claimed in claim 1, characterised in that a base part (14) of said housing includes an expander stud (44) and a top part (16) of said housing includes an expander sleeve (46) and in that said second alignment means (24) includes an alignment hole (24) in said pin-header (20) receiving said expander sleeve (46) therein, said expander sleeve (46) receiving therein said expander stud (44) in such a manner that walls of the expander sleeve (46) are expanded by receiving the expander stud (44) to engage said expander sleeve (46) with said alignment hole (24).

3. The assembly as claimed in claim 1, characterised in that said second alignment means includes an alignment pin engaging pin-receiving portions on the housing (14, 16).

4. The assembly as claimed in any one of the preceding claims, characterised in that the connector (30) includes guide means (32, 33, 34) extending internally and/or externally of the housing (14, 16) for guiding connection of said wiring harness to said pin-header The assembly as claimed in any one of claims 1 to 4, characterised in that the assembly (10) further includes third alignment means (40, 41, 42) for aligning the PCB (12) with the housing (14, 16). P:opcrNsb\k2261950 cmplc W.doc-17/ I V3 -11-

6. The assembly as claimed in claim 2 or 3, characterised in that said pin-header includes an extended portion (26) and said second alignment means (24) is positioned on said extended portion (26).

7. The assembly as claimed in claim 6, characterised in that a neck portion connects said extended portion (26) to said body (27) of said pin-header assembly such that a plane of said extended portion (26) is separated from but substantially parallel with a plane of a body (27) of said pin-header

8. The assembly as claimed in any one of the preceding claims, characterised in that the assembly includes two pin-headers (20) connected to each other by a header connector piece (28).

9. The assembly as claimed in claim 4, characterised in that said guide means includes interlocking means (34) for interlocking engagement of the guide means with the wiring harness. The assembly as claimed in claim 4 to 9, characterised in that the connector includes sealing means between said guide means (32) and said pin-header

11. The assembly as claimed in any one of the preceding claims, characterised in that said housing (14, 16) is formed of moulded plastic in two interlocking parts.

12. A pin-header (20) for a connector assembly (30) of an automotive electronic control unit (10) having a printed circuit board (PCB) the pin-header (20) having first alignment means (21, 22) for mounting the pin-header (20) to the PCB characterised in that the pin-header (20) includes second alignment means (24) for aligning the pin- header (20) with guide walls (32) of a housing (16) of the electronic control unit

13. The pin-header assembly as claimed in claim 12, characterised in that said pin- header includes two pin-header bodies (27) connected to each other by a header connector P:op 11bZ22619O0 compide W.doc17/12103 -12- piece each pin-header body (27) accommodating a plurality of connection pins (21) for engaging said PCB (12) and for cooperating, as part of said connector assembly with a wiring harness.

14. The assembly as claimed in claim 1 or the pin-header as claimed in claim 12, characterised in that said pin-header (20) includes a plurality of pins which form part of said connector The assembly as claimed in claim 1 or the pin-header as claimed in claim 12, characterised in that said pin-header (20) includes a plurality of pin receiving holes, which form part of said connector

16. The pin-header assembly as claimed in claim 13, characterised in that said two pin- header bodies (27) are separable at said header connector piece (28) to create two separate pin-headers DATED this 18 th day of December, 2003 Robert Bosch GmbH by DAVIES COLLISON CAVE Patent Attorneys for the Applicant