CA1048629A - Housing for mounting electronic circuit boards on an engine air filter housing - Google Patents
Housing for mounting electronic circuit boards on an engine air filter housingInfo
- Publication number
- CA1048629A CA1048629A CA76243476A CA243476A CA1048629A CA 1048629 A CA1048629 A CA 1048629A CA 76243476 A CA76243476 A CA 76243476A CA 243476 A CA243476 A CA 243476A CA 1048629 A CA1048629 A CA 1048629A
- Authority
- CA
- Canada
- Prior art keywords
- housing
- circuit board
- air
- air filter
- engine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B77/00—Component parts, details or accessories, not otherwise provided for
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
- F02M35/02—Air cleaners
- F02M35/04—Air cleaners specially arranged with respect to engine, to intake system or specially adapted to vehicle; Mounting thereon ; Combinations with other devices
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2400/00—Control systems adapted for specific engine types; Special features of engine control systems not otherwise provided for; Power supply, connectors or cabling for engine control systems
- F02D2400/18—Packaging of the electronic circuit in a casing
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Casings For Electric Apparatus (AREA)
- Filtering Materials (AREA)
- Cooling Or The Like Of Electrical Apparatus (AREA)
Abstract
Housing for Mounting Electronic Circuit Boards on an Engine Air Filter Housing Abstract of the Disclosure A housing containing a pair of electronic circuit boards removably mounts on the side of an engine air filter housing. The circuit board housing has a generally concave inner face matching the convex co?tour of the air filter housing side wall and is disposed over air circulation openings in the air filter housing side wall. In a first ?, the circuit board housing is of one-piece construction and the electronic circuit boards are disposed interiorly of the outer wall of the circuit board housing and in generally parallel relationship therewith. In a second embodiment, the circuit board housing is of two-piece construction having upper and lower halves. In this embo?iment, the circuit boards are horizontally disposed, one each in each of the two housing halves. Connectors for effecting connection of the circuit boards with the other components of the system which are located exteriorly of the air cleaner housing extend through holes in the circuit board housing. The circuit boards contain electronic control circuitry for the engine, for example, an electronic engine spark timing control system. Other devices such as transducers may also mount on the circuit board housing.
Description
a4s~zs mary of the Inventioll This invention relates to a novel arrangement for mount-ing electronic circuit boards in the engine compartment oE a vehicle.
Among the features and objects of the present invention are to provide an improved mounting arrangement for electronic circuit boards: which can be easily assembled into and disassembled from an engine air filter housing; in which the circuit components are protected from contamination; in which the components are adequately thermally protected even though con-tained in the engine compartment; which provides easy connect-ability to other system components; and which offers other advantages and benefits as will appear more fully hereinafter. ~-In one particular aspect the present invention providesin an engine having an induction air intake system including an air filter housing having a cylindrical side wall, the combina-tion with said air filter housing of: an electronic circuit , board housing containing at least one electronic circuit board - assembly therein; means mounting said circuit board housing on the side wall of said air filter housing; and means communica-ting the interiors of said two housings to provide air circula- -tion within said circuit board housing when the engine is operated.
In another particular aspect the present invention pro-; vides in an engine having an induction air intake system includ-ing an air filter housing having a cylindrical side wall, the combination with said air filtex housing of: an electronic circuit board housing containing an electronic circuit board assembly therein; means mounting said circuit board housing on said air filter housing; means communicating the interiors of said two housings to provide air circulation within said circuit board housing when the engine is operated, and an electronic circuit element mounted on said electronic circuit board ~ assembly but disposed in the path of air `~ ~ -2-mjp/
,. -- ., 1~)48~:iZ9 rculation in said circuit board housing.
In yet another particular aspect the present invention provides in an engine powered vehicle having an induction air intake system for the engine including an air filter housing having a cylindrical side wall and an intake snorkel projecting therefrom and including electronic engine control circuitry, the improvement comprising: means mounting at least portions of said control circuitry on a circuit board; a circuit board mounting housing containing said circuit board therein; means mounting said circuit board mounting housing on said air filter housing circumferentially of said snorkel; and means communicating the interiors of said two housings to provide air circulation within said circuit board mounting housing when the engine is operated.
In a further particular aspect the present invention provides in an engine comprising induction air intake structure including an air filter housing and comprising electronic engine control circuitry, the improvement comprising: a control circuit housing adapted to contain electronic control circuitry; means mounting at least a portion of said electronic engine control circuitry wlthin said control circuit housing; means mounting said control circuit houslng on said air filter housing; and means communicating said two housings to provide air circulation there-between when the engine is operated.
In yet a further particular aspect the present invention provides in an engine comprising induction air intake structure via which air is inducted into the engine and comprising electronic engine control circuitry, the improvement comprising:
means mounting at least a portion of said engine control circuitry on a circuit board; a housing within which said circuit board and said control circuitry portion thereon are contained; and means communicating said air intake structure and said housing comprising means via which air can enter said housing from said air intake :, -.
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~ structure and means via which air can exit said housing to said air intake structure.
. Brief Description of the Drawings The drawings illustrate preferred embodiments of the present invention according to the best mode presently con-` templated in carrying out the invention.
Figure 1 is a fragmentary exploded perspective viewof a portion of a typical vehicle engine compartment including a first embodiment of circuit board housing according to the present invention.
; Figure 2 is a view showing the interior of the circuit board housing of Figure 1 by itself with the circuit boards and thelr receptacles contained therein.
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.' :' :, jl/'~` -2b-10 41511;i 29 ¦ 1g. 3 is a sect1onal view taken along lines 3-3 in Fig. 2.
Fig. 4 is an enlarged sectional view through one l of the circuit boards and its receptacle shown in Fig. 2.
¦ Fig. 5 is a sectional view through the other circuit board and its receptacle shown in Flg. 2.
Fig. 6 is a fragmentary top plan view having portions broken away illustrating a second embodiment of circuit board housing according to the present invention.
Fig. 7 is a fragmentary side elevational view of Fig. 6.
Fig. 8 is a fragmentary sectional view taken in the direction of arrows 8-8 in Fig. 6.
Fig. 9 is a fragmentary end view of Fig. 8.
Fig. 10 is a sectional view taken in the direction of arrows 10 10 in Fig. 6.
Fig. 11 is a plan view of the interior of the upper half of the circuit board housing of Fig. 6 shown by itself.
Fig. 12 is a sectionai view taken in the direction 2Q of arrows 12-12 in Fig. 11.
Fig, 13 is a plan view of the interior of the lower half o~ the circuit board housing shown ln Fig. 6.
Fig. 14 is a fragmentary view taken in the direction of arrow 14 in Flg. 13.
Fig. 15 is a sectional view taken through one of the electrical connector pl~gs lncluded in the arrangement of ig. 6 and is taken in the direction of arrows 15-15 in Fig. 16.
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_~ ~ _ 10~8tiZ9 ¦ Fig. 16 is a plan view Or the connector plug ¦ shown in Fig. 15.
¦ Fig. 17 is a side view Or the connector plug ¦ in Fig. 16.
; 5 ¦ Fig. 18 is a sectional view through the other connector plug included in the arrangemen~ of Flg. 6 and ls taken in the directlon of arrows 18-18 in Fig. 19.
¦ Fig. 19 is a plan vlew of the connector plug of Fig. 18.
Fig, 20 isa side view of the connector plug shown in Fig. 19.
Fig. 21 is a fragmentary sectional view in the direction of arrows 21-21 in Fig. 6.
, Fig. 22 is a side elevational view showing the r inn~rfaao~of the circuit board housing.
Description of the Preferred Embodiments In Fig. l there is shown a portion o~ a typical vehicle engine compartment including an engine 10, a carburetor 12, an air filter housing 14, an ignition coil 16, and a distributor 18. The engine further includes an electronic control ; system for example, an engine spark timing controller which controls the timing of the ignition spark in relation to certain ; control inputs. For example, one input may be the throttle positlon as monitored by a throttle position transducer 20 and ,~ another may be the engine manifold vacuum as monitored by a ; vaouum t sducer 22.
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:_ ~_ ~ ;29 The present invention ls concerned with a novel ¦ mounting arrangement for mounting the electronic circultry ¦ Or the electronic control system in the engine compartment.
¦ More specifically, the present invention, in a first embodiment ¦ as shown in Figs. 1 through 5, provides a circuit board housing ¦ 24 which removably mounts on air cleaner housing 14. Details of ¦ housing 24 are shown in Figs. 1, 2 and 3. Houslng 24 pre-¦ ferably is a molded plastic element suitable for use with the higher temperatures which are generally encounte~red in the B l engine ccmpartment; for example, ~1~6S ~ d~nylon or glass-fllled polyester are suitable. Housing 24 is of generally concave shape with the inner face thereof facing radially l inwardly of air filter housing 14. Air fllter housing 14 ¦ is generally conventional; however, in accordance with the principles of the present invention the side wall of housing 14 i provided with one or more air circulation openings over which circuit board housing 24 is disposed. Such openings are illustratively shown at 26 and 28 in Fig. 3. Attachment means fo attaching circuit board housing 24 to air cleaner housing 14 are provided in the form of outwardly turned tabs 30 and 32 on th I side wall of air filter housing 14. Circuit board housing 24!, iS provided with a radially outer wall 34 which extends be-, tween the points at which it attaches to air filter housing 14.
This outer wall 34 is parallel to the axis of the air filter hous ing but is sp~ced radially outwardly from the nominal diameter the a f1lter housing. Circuit board houslng 24 further , . .
., --~_ 1~48~j29 includes a top wall 36 and a bottom wall 38 which proJect ¦ radially inwardly from the outer wall 34. Both top and bottom ¦ walls 36, 38 have their inner peripher~es generally circularly contoured to match the contour of the side wall of houslng 14 ¦ so that the circuit board housing seats on the air filter hous~ng.
Housing 24 removably mounts on housing 14 in the following fashion, Tab 30 is provided with a slot 40 into which the free end of a r1ght angle pro~ecting flange 42 on one end o~
housing 24 may be inserted. With-the houslng 24 appropriately oriented to permit insertion of the free end of ed8e 42 into slot 40, the edge is inserted into the 810t, and housing 24 is piv~ted thereabout to bring the housing to the posltion shown in Fig. 3.
A pair o~ holes are provided in tab 32 and matching clearance -holes in the Juxtaposed edge 44 of housing 24 so that attachment screws 46 may~be inserted through the clearance holes to engage ~ ` the holes in tab 32 and secure the attachment. With housing 24 ;~ secured to housing 14 it will be noted that the free edge 42 interlocks behind tab 30.
A pair of electronlc circuit board assemblies 48 and 50 are mounted interiorly of housing 24 within a pair of sheet metal receptacles 52 and 54,respectively. Greater details of the two circuit board assemblies 48, 50 and their respective receptacles 52, 54 are shown in Figs. 4 and 5. The circuit board f each circuit board assembly is o~ rectangular shape and contain s _ ~
lQ48629 :
thereon a large number of the electronic circuit components forming electronic circuits of the engine control system.
Each sheet metal receptacle has a rectangular shape similar to that of the corresponding circuit board assembly. Each circuit board assembly also contains an electrical connector plug which mates with a mating connector plug (not shown in Figs. 2-5) to effect electrical connection of the circuits on the circuit board assembly with components of the system which are external to the circuit board assemblies. The connector plug for circuit board assembly 48 is designated by the reference numeral 56 and that for circuit board assembly 50 by the reference numeral 58.
Each circuit board assembly 48, 50 and its corres-ponding receptacle form an individual unit which removably mounts on wall 34 of housing 24. The circuit board ~ -assemblies are potted in their respective receptacles, and the receptacles are provided with apertured side flanges, or tabs, 60 via which the units attach to wall 34 by means of attaching screws 62. Clearance holes 64, 66 are provided in wall 34 for connector plug 56, 58 respectively, and annular gaskets 68, 70 seal between each connector plug and its clearance hole 64, 66.
Each circuit board assembly 48, 50 mounts within its receptacle 52, 54 in the following fashion. There are provided in the radially inner wall 52a, 54a of each receptacle several localized indentations illustratively indicated by the reference numeral 72. Each receptacle is oriented with its wall 52a, 54a horizontal and its interior facing up. The circuit board assemblies are positioned within their receptacles to rest on in-' '' ' ~njp/
1 1~48f~29 dentations 72, thereby providing a clearance space between each board and the wall 52a, s4a of itg receptacle. If necessary, one or more bendable retention tabs, such ag 74, may be provided on l a receptacle to assist in holding and locating the clrcult board.
¦ A suitable potting compound is then poured into the receptacle to a desired rill level 76 suf~iclent to cover the circuit board and virtually all the individual electronic circuit components thereon. Because-i~dentatlons 72 are only localized and because the overall dimensiong of each circuit board are slightly less than those of lts receptacle, the potting compound flows around the edges of the board to substantially flll the space between the board and the receptacle wall. It may be found desirable to facilitate filling by provlding holes in the olrcuit board. Once the receptacle has been filled, the pottlng com-pound is allowed to cure into a rubbery-llke encapsulant.
Electrical terminals, such as 78 may protrude above the fill leve 76 to provide for connection intern~Y of housing 24, for example between the two circuit boards. Other devices may mount on the units, for example a heat sink 80 for a power transistor 82 usedin the circuitry associated with board 50.
It is contemplated that other devices may mount on housing 24, for example vacuum transducer 22, which mounts on wall 34 ~etween the two circuit board receptacles. Electrical terminals 84 for'transducer 22 are interior of housing 24 and may connect by lead wires with selected terminals 78. A nipple 86 to which manifold vacuum is conducted is located exteriorly so that a vacuum hose may be inserted thereon.
_ _ I lV4~29 ¦ An especially good pottlng materia~ ~or the units is G l silicone rubber, such as Dow-Corning ~'Sylgard~' or General ¦ Electric l'RTV627". This material posses physical properties ¦ which are especially desirable with the present invention.
¦ For example, the material exhibits excellent dielectric ¦ characteristicsj very low thermal conductivity, remains l reasonably pliable at very low temperatures and retains its ¦ shape at very high temperatures. Because of its low thermal conductivity, the potting material thermally insulates those components which it covers. Because o~ the extremely low power dissipation of most ofthe electrical circult components mounted on the circuit boards, these components can be completely covered by potting material. However, i~ a component dissipates a larger a~ount o~ heat, it may be desirable to expose same to the interior of housing 24. With the engine operating, the present invention a~fords a certain air circulation within housing 24 caused by the induction ef~ect o~ air drawn lnto the carburetor through the air filter housing. Even though the snorkel 88, via which air enters the air rllter housin~
is located essentially diametrically opposite circult board housing 24, the provision of air clrculation cpenings 26, 28 exposes the interior of housing 24 to the interior air filter housing 14 so that air flow and air turbulence within housing 14 gznerate air currents within housing 24 across the receptacle and circuit board assembly units. Thus, in the case o~
transistor 82 and its heat sink 80, there is provided a certain '~-- ~
convective cooling. In order to maintain the temperature o~ the intake air as close to ambient as possible, lt may be beneficial to connect air intake ho~e 90 to snorkel 88 80 that air can be gathered at a locatlon remove rrom the englne comp~rtment.
If desired~ either or both the hose 90 and the air filter housing 14 may be covered with insulatlon to further mln~mize temperature rise in the induction air. With the lnvention it is possible to accurately sense the amblent air temperature by means of a temperature responsive element such a~ a thermistor mounted ln circuit on one Or the circult boards, but proJecting from its receptacle to be disposed in the air withln the houslng. It may also be desirable to provide an air scoop or diverter at one of the air circulation openings to promote air circulatlon within the housing. ' The second embodiment of the present inventlon shown ¦
in Figs. 6 through 22 possesses a number of features which are dlfferent from those of the first embodiment. The second embodiment comp,rises a circult board housing lOO which is of two-piece construction. Specifically, h'ousing 100 comprises a molded plastic element 102 forming the upper half of the housing and a second molded plastic element 104 forming the lower hal~
of the houslng. The two houslng elements are detachably secured together along their mating surfaces by means of a plurality of attachment screws 106 which extend through holes in bosses formed at intervals around the two elemLnts.
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1~)48629 Detalls of the upper and lower housing elements 102, lO4 are best shown in Figs. 11 through 14 whlch illustrate the two houslng elements by themselves. As can be seen in Figs.
¦ 11 and 12,upper housing element 102 comprises a rectangularly 5 1 shaped circuit-board-receiving pocket 108. The mating surface ¦ 110 of element 10~ which mates with lower houslng element ¦ 104 lies in a flat plane WhiCh i8 diæposed horizontally when housing 100 is mounted on air filter housing 14. Similarly, I lower housing element 104 has a rectangularly shaped circuit-board-recelving pocket 112 and a mQting ~urrace 114, which mates with surface 110 when the two elements 102, 104 are assembled together. HoweverJ the two mating surraces 110, 114 are not necessarily conti~ous-throughout, In order to provide a seal between the upper and lower~housing elements around three sldes of the two clrcuit-board-recelving pocke~ts 108, 112, there is provided on element 102 a raised bead 116 on surface 110 extending around three sideQ Or pocket 108. There is also provided in element 104 a complementary recess 118 in which bead 116 lodges when the two housing halves are assembled. By making the height Or bead 116 slightly greater than the depth Or recess 118 throughout their respective lengths, a continuous sealing contact is erfected between the two when assembled.
Accordingly, it will be appreciated that the mating surfaces 110, 112 are not necessarily in continuous contact with each other throughout. ~his feature has the advantage of eliminating the need for a separate sealing gasket between the two~housing halves.
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Considering Figs. 6 and 11 through 14 in greater . ¦ detail, one will observe that housing 100 is further endowed with an intake alr scoop.l20 having an intake opening 122 and an air discharge outlet 124 which is spaced circumferentially of 1 scoop 120. The top wall of air scoop 120 is pro~ided by the ~ ¦ triangularly shaped projection 126 in element 102 whlle ; ¦ the remainder of the air scoop is formed in lower element 104.
. ¦ Similarly, the top of discharge outlet 124 is provided by the : I portion 128 of element 102 and the remainder thereof ln element l 104. With the two housing elements assembled together, and mount d l on air filter housing l4 as shown in Fig. 6, induction air I ~c~ s~o~k~
B entering ~ho~u~h~the air cleaner ~e~e~is drawn in the directio of the arrows into scoop 120, passing through the interior of housing 100 and discharging at outlet 124. Air flow through the housing may be promoted by the location of an upstanding diverter 130 ad~acent the intake opening 122 of scoop 120.
: ` As will become apparent, the air flow circulation through housing 100 provides effective cooling for the electronic circuit components contained within the housing.
Looking now at Figs. 10 and 21, along with Figs. 11-1 , a first electronic circuit board assembly 132, containing .
a number of electronic circuits thereon (which are not j illustrated in the drawing for the sake Or clarity), is contained within pocket 108 while a second electronic circuit board , 25 assembly 134 is contained within pocket 112. Desirably, each :~
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1~48~Z9 -circuit board is potted within its resRectiye housing element by means of suitable pott-ing material. An advantage of the -instant arrangement concerns assembly of each circuit board assembly into its corresponding housing element which is as follows. With the interior of the housing element pocket facing upwardly, the appropriate circuit board as.sembly is placed within its pocket so that the circuit board itself rests upon one or more individual ledges 136 which are pro-vided in the pocket. For the first circuit board assembly, there are provided four ledges 136 (Fig. 11~ within pocket 108, and these ledges are formed integrally with element 102.
A feature is to provide one or more locating pins in element 102 which facilitate the correct location of the circuit board assembly within the pocket and which can prevent the circuit board assembly from being oriented 180~ from the -position which it shou]d occupy. For example, element 102 is provided with a pair of integral locating pins 138 which project upwardly from raised bosses 140 formed within pocket 108. The circuit board of circuit board assembly 132 is provided with a matching hole pattern to permit the circuit board assembly to be located on pins 138 so that the circuit board itself comes to rest on the ledges 136 and the bosses 140. With the circuit board thus located, the locating pins 138 protrude substantially above the surface of the circuit board and may be deformed, as by heat staking, into a blob (as shown in Fig. 10) which retains the circuit board assembly in the desired position. Pottin~ material may now be poured into the pocket to a desired fill level 141 after which the material is allowed to cure into a rubbery-like encapsulant for the circuit board and most of the components thereon.
As mentioned in connection with the first mjp/
lU48629 ernbodiment, filling is racilitated by providing one or more openin~s in the clrcuit board to permit the potting material to flow around and beneath the circuit board to avoid unfilled pockets upon curing.
For the lower circuit board assembly 134, which is contained within element 104, there is provided only a single ledge 136 and a single locating pin 138 and boss 140, both of which are located toward the left hand side of pocket 112 as viewed in Fig. 13. The right hand side of the circuit board 134 is both located and supported by virtue of an electrical connector plug assembly 142. As best shown in Figs. 15 and 21, circuit board assembly 134 has the connector plug 142 mounted thereon so that the connector plug extends from the c~rcuit board downwardly through a rectangular opening 144 formed in the lower' wall of housing element 104 within pocket 112. The design of the plastic shell of connector plug assembly 142 is;~such that when the circuit board assembly is being assembled into housing element 104 the plug assembly passes through opening 144 camming a retention tab 146 on the plug shell out Or the way. As the circuit board assembly locates in the intended positlon, the re-tention tab 146 clears the wall of the housing and the inherent resiliency thereof brings the tab into interlocking engagement w~th the housing as shown in Fig. 15. In order to seal around opening 144 between the connectoF plug shell and the housing wall '.~ . ' ,.' :__ _ _ ~
1 1~48~Z9 ¦ a cornpressible sealing gasket 148 ls disposed around the shell l to be compressed between the housing wall and a back-up flange ¦ 150 formed around the shell. The illustrated connector plug ¦ contains four electrical terminal pins 152 which are intended ¦ to effect electrical connection of selected circults on the ¦ circuit board assembly with mating terminal pins in a matlng B l connector plug which mates with plug 142 to~a~rying the circuits associated wlth the terminal plns ~o electrical devices located remotely from houslng 100. With the lower circuit board assembly 134 located within pocket 112, locating pin 138 may be deformed and then potting material may be poured into the pocket to a desired ~ill level 154.
The upper circuit board assembly 132 is provided with an eight terminal pin connector plug assembly 156 which is similar to connector plug assembly 142. However, unlike connector plug 142, connector plug 156 does not pass through an openlng in lts own housing. Rather, connector plug 156 pro~ects in the opposite directlon relative to its mountlng pocket. The connector plug 156 is so located and the two halves of the housin~
are so designed that when the two housing halves are assembled together~ the connector plug 156 pro~ects through a matching opening 158 in the opposite housing halr. This can be seen in detall in Figure 18 where the shell of connector plug assembly 156 passes through opening 158 and a sealing gasket 160 seals bet-~en two 1A the same manner as dld the seal ~8 for the oth t :,'` ' .
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` 1¢~48629 connector plug with respect to its housing. It will be observed that the shell of connector plug 156 lacks any type of interlocking retention tab such as 146 for the connector plug 142. Indeed, it is desirable that the shell of connector plug assembly 156 not have any such retention tab so that the two halves of the housing may be readily separated from each other should such disassembly be necessary. By providing such an arrangement, connection of mating connector plugs is facilitated since both are adjacent.
Furthermore, the arrangement is vertically compact which is desirable in a vehicle engine compartment.
Where the circuit configuration is such that electrical connections are requi;red between the t~o circuit board assemblies such may be readily efEected by providing terminal pins such as indicated at 162 (Fig. 10~ on one of the circuit boards which project above the leyel of the potting material. Leadwires from the other circuit board may then be soldered to the terminal pins 162 at a level above the potting material. Where a circuit element dissi-pates a large amount of heat it is desirable to mount same in the path of air flow through the housing. An example is shown in Fig. 2]. wherein a power transistor 164 and associated heat sink 166 are mounted on upper circuit board assembly 132.
The transistor 164 is attached by means of attachment screws 168 passing through the circuit board to engage tapped holes in the mounting base of the transistor, the heat sink 165 and an insulating spacer 170 being sandwiched therebetween. Heat -generated within the power transistor is dissipated via the transistor casing and heat sink to the circulating air passing through the housing. In this way the maximum temperature of the transistor is maintained within an acceptable limit. Like-wise, as mentioned in connection with the first embodiment, .-:
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1~48f~9 the invention permits the measu~emellt of a~)~ient temperature air by means of a temperature sensing element electrically connected in circuit with one of the circuit boards but being disposed above the level of potting material to be exposed to the ambient air passing througll the circuit board housing.
By way of examp]e, the thermistor 172 in Fig. 21 can sense the temperature of the air and is preferably located upstream of the transistor and heat sink so as to not be influenced by any temperature rise in the air due to the heat dissipation by the transistor and heat sink.
Housing 100 is also designed to accommodate a transducer like the vacuum transducer shown in the first embodiment. However, the arrangément of the second embodiment in this regard offers important advantages over the arrange-ment of the first embodiment. As best seen in ~igs. 6 through 9, a transducer 174 mounts on housing 100 by being mechanically trapped between the two housing halves. ~By way oi example, transducer 174 may be a vacuum-actuated variable inductance type as disclosed and claimed in copending appli-cation Serial No. 243,475, filing date January 13, 1976. This type of transducer comprises a generally cylindrical vacuum actuator portion 176 and a smaller cylindrical coil portion 178. The lower housing element 104 immediately adjacent the left hand side of pocket 112 as viewed in Fig. 13 contains a receptacle 180 into which the transducer 174 is inserted.
; ~eceptacle 180 is generally semi-cylindrically shaped and com-prises an inner portion 182 whlch is adapted to receive the coil portion 178 of the transducer, and an enlarged outer portion 184 which is adapted to accommodate the larger diameter of the vacuum actuator portion 176 of the transducer. A groove 186 is formed in the outer portion 184 and receives the lowe~
portion of a flange 188 provided on the transducer adjacent ~he ' mjp/
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` 1¢~48~i29 juncture of the Yacuum actuator portion and the coil portion.
As best seen in Fig. 14, the cross section of receptacle 180, and its severRl portions 182, 184, and 186, is such that the surfaces thereof lie on respective truly semi-cylindrical surfaces about and below an axial centerline 189. Above the centerline 189, the respective surface portions continue as spaced parallel walls extending upwardly from the truly semi-cylindrical portions. Hence, the receptacle 180 and its portions 182, 184 and 186 may be considered as U-shaped as viewed in ~'ig. 14. The flange 188 on the transducer has its lower portion designed to complement the U-shaped groove 186.
This shape can be seen in Fig. 9. This construction permits transducer 174 to be readily inserted into receptacle 180 so that the U-shaped flange 188 fits within and registers with the U-shaped groove 186. When so inserted the transducer is correctly located both circumferentially and axially, and relative rotation between housing element 104 and the trans-! ducer 174 about the centerline 189 is precluded. Thus, the transducer mounting arrangemellt advRntageously provides a self-locating, anti-rotation feature, and furthermore eliminates the need for any separate mechRnicRl fasteners. The upper housing element 102 is designed with a circularly contoured segment 190 and a circularly contoured groove 192 formed therein to engage the circularly contoured upper portion of the transducer flange 188 when the two housing halves are --assembled. It will be observed that when the two housing halves are assembled, the portions of the surface 110 immediately adjacent the ends of groove 192 overlie the tops of the lower U-shaped portions of flange 188 thereby also precluding rotation of the trRnsducer. Two electrical termi-nals 194, 196 at the inner end of the transducer, are connect-ed with the lower circuit board assem~]y 13~ by means of lead mjp/
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1~48629 wires 19~, 200 ~hich lead from the termina~s througll suitable passageways formed in housing element 104. This transducer mounting and connection arrangement enhances assembly and serviceability. Also, the flange and groove seals between the housing and the transducer to prevent the intrusion of contam-inants.
In the assembled unit it is desirable to adhere a sealing gasket 202 on the concave inner face of housing 100 as shown in Fig. 22. The sealing gasket includes suitable cut-outs 204, 206 for the air scoop and the air discharge outlet respectively as well as cutaways 20~ for the attaching holes via which the housing is attached to the air cleaner housing 14. As can be seen in Fig. 6, housing 100 is attached to air cleaner housing 14 by means of attachment screws 210 which pass through suitable holes in the side wall of the air filter housing to threadly engage matching holes provided in housing -100. This permits the housing to be conveniently attached to and removed from the air filter housing. With the provision of the sealing gasket and the design of the two housing elements, the interior of the unit is adequately sealed so that the only exterior communication is via the air inlet and outlet openings.
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Among the features and objects of the present invention are to provide an improved mounting arrangement for electronic circuit boards: which can be easily assembled into and disassembled from an engine air filter housing; in which the circuit components are protected from contamination; in which the components are adequately thermally protected even though con-tained in the engine compartment; which provides easy connect-ability to other system components; and which offers other advantages and benefits as will appear more fully hereinafter. ~-In one particular aspect the present invention providesin an engine having an induction air intake system including an air filter housing having a cylindrical side wall, the combina-tion with said air filter housing of: an electronic circuit , board housing containing at least one electronic circuit board - assembly therein; means mounting said circuit board housing on the side wall of said air filter housing; and means communica-ting the interiors of said two housings to provide air circula- -tion within said circuit board housing when the engine is operated.
In another particular aspect the present invention pro-; vides in an engine having an induction air intake system includ-ing an air filter housing having a cylindrical side wall, the combination with said air filtex housing of: an electronic circuit board housing containing an electronic circuit board assembly therein; means mounting said circuit board housing on said air filter housing; means communicating the interiors of said two housings to provide air circulation within said circuit board housing when the engine is operated, and an electronic circuit element mounted on said electronic circuit board ~ assembly but disposed in the path of air `~ ~ -2-mjp/
,. -- ., 1~)48~:iZ9 rculation in said circuit board housing.
In yet another particular aspect the present invention provides in an engine powered vehicle having an induction air intake system for the engine including an air filter housing having a cylindrical side wall and an intake snorkel projecting therefrom and including electronic engine control circuitry, the improvement comprising: means mounting at least portions of said control circuitry on a circuit board; a circuit board mounting housing containing said circuit board therein; means mounting said circuit board mounting housing on said air filter housing circumferentially of said snorkel; and means communicating the interiors of said two housings to provide air circulation within said circuit board mounting housing when the engine is operated.
In a further particular aspect the present invention provides in an engine comprising induction air intake structure including an air filter housing and comprising electronic engine control circuitry, the improvement comprising: a control circuit housing adapted to contain electronic control circuitry; means mounting at least a portion of said electronic engine control circuitry wlthin said control circuit housing; means mounting said control circuit houslng on said air filter housing; and means communicating said two housings to provide air circulation there-between when the engine is operated.
In yet a further particular aspect the present invention provides in an engine comprising induction air intake structure via which air is inducted into the engine and comprising electronic engine control circuitry, the improvement comprising:
means mounting at least a portion of said engine control circuitry on a circuit board; a housing within which said circuit board and said control circuitry portion thereon are contained; and means communicating said air intake structure and said housing comprising means via which air can enter said housing from said air intake :, -.
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~ structure and means via which air can exit said housing to said air intake structure.
. Brief Description of the Drawings The drawings illustrate preferred embodiments of the present invention according to the best mode presently con-` templated in carrying out the invention.
Figure 1 is a fragmentary exploded perspective viewof a portion of a typical vehicle engine compartment including a first embodiment of circuit board housing according to the present invention.
; Figure 2 is a view showing the interior of the circuit board housing of Figure 1 by itself with the circuit boards and thelr receptacles contained therein.
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.' :' :, jl/'~` -2b-10 41511;i 29 ¦ 1g. 3 is a sect1onal view taken along lines 3-3 in Fig. 2.
Fig. 4 is an enlarged sectional view through one l of the circuit boards and its receptacle shown in Fig. 2.
¦ Fig. 5 is a sectional view through the other circuit board and its receptacle shown in Flg. 2.
Fig. 6 is a fragmentary top plan view having portions broken away illustrating a second embodiment of circuit board housing according to the present invention.
Fig. 7 is a fragmentary side elevational view of Fig. 6.
Fig. 8 is a fragmentary sectional view taken in the direction of arrows 8-8 in Fig. 6.
Fig. 9 is a fragmentary end view of Fig. 8.
Fig. 10 is a sectional view taken in the direction of arrows 10 10 in Fig. 6.
Fig. 11 is a plan view of the interior of the upper half of the circuit board housing of Fig. 6 shown by itself.
Fig. 12 is a sectionai view taken in the direction 2Q of arrows 12-12 in Fig. 11.
Fig, 13 is a plan view of the interior of the lower half o~ the circuit board housing shown ln Fig. 6.
Fig. 14 is a fragmentary view taken in the direction of arrow 14 in Flg. 13.
Fig. 15 is a sectional view taken through one of the electrical connector pl~gs lncluded in the arrangement of ig. 6 and is taken in the direction of arrows 15-15 in Fig. 16.
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_~ ~ _ 10~8tiZ9 ¦ Fig. 16 is a plan view Or the connector plug ¦ shown in Fig. 15.
¦ Fig. 17 is a side view Or the connector plug ¦ in Fig. 16.
; 5 ¦ Fig. 18 is a sectional view through the other connector plug included in the arrangemen~ of Flg. 6 and ls taken in the directlon of arrows 18-18 in Fig. 19.
¦ Fig. 19 is a plan vlew of the connector plug of Fig. 18.
Fig, 20 isa side view of the connector plug shown in Fig. 19.
Fig. 21 is a fragmentary sectional view in the direction of arrows 21-21 in Fig. 6.
, Fig. 22 is a side elevational view showing the r inn~rfaao~of the circuit board housing.
Description of the Preferred Embodiments In Fig. l there is shown a portion o~ a typical vehicle engine compartment including an engine 10, a carburetor 12, an air filter housing 14, an ignition coil 16, and a distributor 18. The engine further includes an electronic control ; system for example, an engine spark timing controller which controls the timing of the ignition spark in relation to certain ; control inputs. For example, one input may be the throttle positlon as monitored by a throttle position transducer 20 and ,~ another may be the engine manifold vacuum as monitored by a ; vaouum t sducer 22.
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:_ ~_ ~ ;29 The present invention ls concerned with a novel ¦ mounting arrangement for mounting the electronic circultry ¦ Or the electronic control system in the engine compartment.
¦ More specifically, the present invention, in a first embodiment ¦ as shown in Figs. 1 through 5, provides a circuit board housing ¦ 24 which removably mounts on air cleaner housing 14. Details of ¦ housing 24 are shown in Figs. 1, 2 and 3. Houslng 24 pre-¦ ferably is a molded plastic element suitable for use with the higher temperatures which are generally encounte~red in the B l engine ccmpartment; for example, ~1~6S ~ d~nylon or glass-fllled polyester are suitable. Housing 24 is of generally concave shape with the inner face thereof facing radially l inwardly of air filter housing 14. Air fllter housing 14 ¦ is generally conventional; however, in accordance with the principles of the present invention the side wall of housing 14 i provided with one or more air circulation openings over which circuit board housing 24 is disposed. Such openings are illustratively shown at 26 and 28 in Fig. 3. Attachment means fo attaching circuit board housing 24 to air cleaner housing 14 are provided in the form of outwardly turned tabs 30 and 32 on th I side wall of air filter housing 14. Circuit board housing 24!, iS provided with a radially outer wall 34 which extends be-, tween the points at which it attaches to air filter housing 14.
This outer wall 34 is parallel to the axis of the air filter hous ing but is sp~ced radially outwardly from the nominal diameter the a f1lter housing. Circuit board houslng 24 further , . .
., --~_ 1~48~j29 includes a top wall 36 and a bottom wall 38 which proJect ¦ radially inwardly from the outer wall 34. Both top and bottom ¦ walls 36, 38 have their inner peripher~es generally circularly contoured to match the contour of the side wall of houslng 14 ¦ so that the circuit board housing seats on the air filter hous~ng.
Housing 24 removably mounts on housing 14 in the following fashion, Tab 30 is provided with a slot 40 into which the free end of a r1ght angle pro~ecting flange 42 on one end o~
housing 24 may be inserted. With-the houslng 24 appropriately oriented to permit insertion of the free end of ed8e 42 into slot 40, the edge is inserted into the 810t, and housing 24 is piv~ted thereabout to bring the housing to the posltion shown in Fig. 3.
A pair o~ holes are provided in tab 32 and matching clearance -holes in the Juxtaposed edge 44 of housing 24 so that attachment screws 46 may~be inserted through the clearance holes to engage ~ ` the holes in tab 32 and secure the attachment. With housing 24 ;~ secured to housing 14 it will be noted that the free edge 42 interlocks behind tab 30.
A pair of electronlc circuit board assemblies 48 and 50 are mounted interiorly of housing 24 within a pair of sheet metal receptacles 52 and 54,respectively. Greater details of the two circuit board assemblies 48, 50 and their respective receptacles 52, 54 are shown in Figs. 4 and 5. The circuit board f each circuit board assembly is o~ rectangular shape and contain s _ ~
lQ48629 :
thereon a large number of the electronic circuit components forming electronic circuits of the engine control system.
Each sheet metal receptacle has a rectangular shape similar to that of the corresponding circuit board assembly. Each circuit board assembly also contains an electrical connector plug which mates with a mating connector plug (not shown in Figs. 2-5) to effect electrical connection of the circuits on the circuit board assembly with components of the system which are external to the circuit board assemblies. The connector plug for circuit board assembly 48 is designated by the reference numeral 56 and that for circuit board assembly 50 by the reference numeral 58.
Each circuit board assembly 48, 50 and its corres-ponding receptacle form an individual unit which removably mounts on wall 34 of housing 24. The circuit board ~ -assemblies are potted in their respective receptacles, and the receptacles are provided with apertured side flanges, or tabs, 60 via which the units attach to wall 34 by means of attaching screws 62. Clearance holes 64, 66 are provided in wall 34 for connector plug 56, 58 respectively, and annular gaskets 68, 70 seal between each connector plug and its clearance hole 64, 66.
Each circuit board assembly 48, 50 mounts within its receptacle 52, 54 in the following fashion. There are provided in the radially inner wall 52a, 54a of each receptacle several localized indentations illustratively indicated by the reference numeral 72. Each receptacle is oriented with its wall 52a, 54a horizontal and its interior facing up. The circuit board assemblies are positioned within their receptacles to rest on in-' '' ' ~njp/
1 1~48f~29 dentations 72, thereby providing a clearance space between each board and the wall 52a, s4a of itg receptacle. If necessary, one or more bendable retention tabs, such ag 74, may be provided on l a receptacle to assist in holding and locating the clrcult board.
¦ A suitable potting compound is then poured into the receptacle to a desired rill level 76 suf~iclent to cover the circuit board and virtually all the individual electronic circuit components thereon. Because-i~dentatlons 72 are only localized and because the overall dimensiong of each circuit board are slightly less than those of lts receptacle, the potting compound flows around the edges of the board to substantially flll the space between the board and the receptacle wall. It may be found desirable to facilitate filling by provlding holes in the olrcuit board. Once the receptacle has been filled, the pottlng com-pound is allowed to cure into a rubbery-llke encapsulant.
Electrical terminals, such as 78 may protrude above the fill leve 76 to provide for connection intern~Y of housing 24, for example between the two circuit boards. Other devices may mount on the units, for example a heat sink 80 for a power transistor 82 usedin the circuitry associated with board 50.
It is contemplated that other devices may mount on housing 24, for example vacuum transducer 22, which mounts on wall 34 ~etween the two circuit board receptacles. Electrical terminals 84 for'transducer 22 are interior of housing 24 and may connect by lead wires with selected terminals 78. A nipple 86 to which manifold vacuum is conducted is located exteriorly so that a vacuum hose may be inserted thereon.
_ _ I lV4~29 ¦ An especially good pottlng materia~ ~or the units is G l silicone rubber, such as Dow-Corning ~'Sylgard~' or General ¦ Electric l'RTV627". This material posses physical properties ¦ which are especially desirable with the present invention.
¦ For example, the material exhibits excellent dielectric ¦ characteristicsj very low thermal conductivity, remains l reasonably pliable at very low temperatures and retains its ¦ shape at very high temperatures. Because of its low thermal conductivity, the potting material thermally insulates those components which it covers. Because o~ the extremely low power dissipation of most ofthe electrical circult components mounted on the circuit boards, these components can be completely covered by potting material. However, i~ a component dissipates a larger a~ount o~ heat, it may be desirable to expose same to the interior of housing 24. With the engine operating, the present invention a~fords a certain air circulation within housing 24 caused by the induction ef~ect o~ air drawn lnto the carburetor through the air filter housing. Even though the snorkel 88, via which air enters the air rllter housin~
is located essentially diametrically opposite circult board housing 24, the provision of air clrculation cpenings 26, 28 exposes the interior of housing 24 to the interior air filter housing 14 so that air flow and air turbulence within housing 14 gznerate air currents within housing 24 across the receptacle and circuit board assembly units. Thus, in the case o~
transistor 82 and its heat sink 80, there is provided a certain '~-- ~
convective cooling. In order to maintain the temperature o~ the intake air as close to ambient as possible, lt may be beneficial to connect air intake ho~e 90 to snorkel 88 80 that air can be gathered at a locatlon remove rrom the englne comp~rtment.
If desired~ either or both the hose 90 and the air filter housing 14 may be covered with insulatlon to further mln~mize temperature rise in the induction air. With the lnvention it is possible to accurately sense the amblent air temperature by means of a temperature responsive element such a~ a thermistor mounted ln circuit on one Or the circult boards, but proJecting from its receptacle to be disposed in the air withln the houslng. It may also be desirable to provide an air scoop or diverter at one of the air circulation openings to promote air circulatlon within the housing. ' The second embodiment of the present inventlon shown ¦
in Figs. 6 through 22 possesses a number of features which are dlfferent from those of the first embodiment. The second embodiment comp,rises a circult board housing lOO which is of two-piece construction. Specifically, h'ousing 100 comprises a molded plastic element 102 forming the upper half of the housing and a second molded plastic element 104 forming the lower hal~
of the houslng. The two houslng elements are detachably secured together along their mating surfaces by means of a plurality of attachment screws 106 which extend through holes in bosses formed at intervals around the two elemLnts.
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1~)48629 Detalls of the upper and lower housing elements 102, lO4 are best shown in Figs. 11 through 14 whlch illustrate the two houslng elements by themselves. As can be seen in Figs.
¦ 11 and 12,upper housing element 102 comprises a rectangularly 5 1 shaped circuit-board-receiving pocket 108. The mating surface ¦ 110 of element 10~ which mates with lower houslng element ¦ 104 lies in a flat plane WhiCh i8 diæposed horizontally when housing 100 is mounted on air filter housing 14. Similarly, I lower housing element 104 has a rectangularly shaped circuit-board-recelving pocket 112 and a mQting ~urrace 114, which mates with surface 110 when the two elements 102, 104 are assembled together. HoweverJ the two mating surraces 110, 114 are not necessarily conti~ous-throughout, In order to provide a seal between the upper and lower~housing elements around three sldes of the two clrcuit-board-recelving pocke~ts 108, 112, there is provided on element 102 a raised bead 116 on surface 110 extending around three sideQ Or pocket 108. There is also provided in element 104 a complementary recess 118 in which bead 116 lodges when the two housing halves are assembled. By making the height Or bead 116 slightly greater than the depth Or recess 118 throughout their respective lengths, a continuous sealing contact is erfected between the two when assembled.
Accordingly, it will be appreciated that the mating surfaces 110, 112 are not necessarily in continuous contact with each other throughout. ~his feature has the advantage of eliminating the need for a separate sealing gasket between the two~housing halves.
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_ 1048~iZ~ ~
Considering Figs. 6 and 11 through 14 in greater . ¦ detail, one will observe that housing 100 is further endowed with an intake alr scoop.l20 having an intake opening 122 and an air discharge outlet 124 which is spaced circumferentially of 1 scoop 120. The top wall of air scoop 120 is pro~ided by the ~ ¦ triangularly shaped projection 126 in element 102 whlle ; ¦ the remainder of the air scoop is formed in lower element 104.
. ¦ Similarly, the top of discharge outlet 124 is provided by the : I portion 128 of element 102 and the remainder thereof ln element l 104. With the two housing elements assembled together, and mount d l on air filter housing l4 as shown in Fig. 6, induction air I ~c~ s~o~k~
B entering ~ho~u~h~the air cleaner ~e~e~is drawn in the directio of the arrows into scoop 120, passing through the interior of housing 100 and discharging at outlet 124. Air flow through the housing may be promoted by the location of an upstanding diverter 130 ad~acent the intake opening 122 of scoop 120.
: ` As will become apparent, the air flow circulation through housing 100 provides effective cooling for the electronic circuit components contained within the housing.
Looking now at Figs. 10 and 21, along with Figs. 11-1 , a first electronic circuit board assembly 132, containing .
a number of electronic circuits thereon (which are not j illustrated in the drawing for the sake Or clarity), is contained within pocket 108 while a second electronic circuit board , 25 assembly 134 is contained within pocket 112. Desirably, each :~
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1~48~Z9 -circuit board is potted within its resRectiye housing element by means of suitable pott-ing material. An advantage of the -instant arrangement concerns assembly of each circuit board assembly into its corresponding housing element which is as follows. With the interior of the housing element pocket facing upwardly, the appropriate circuit board as.sembly is placed within its pocket so that the circuit board itself rests upon one or more individual ledges 136 which are pro-vided in the pocket. For the first circuit board assembly, there are provided four ledges 136 (Fig. 11~ within pocket 108, and these ledges are formed integrally with element 102.
A feature is to provide one or more locating pins in element 102 which facilitate the correct location of the circuit board assembly within the pocket and which can prevent the circuit board assembly from being oriented 180~ from the -position which it shou]d occupy. For example, element 102 is provided with a pair of integral locating pins 138 which project upwardly from raised bosses 140 formed within pocket 108. The circuit board of circuit board assembly 132 is provided with a matching hole pattern to permit the circuit board assembly to be located on pins 138 so that the circuit board itself comes to rest on the ledges 136 and the bosses 140. With the circuit board thus located, the locating pins 138 protrude substantially above the surface of the circuit board and may be deformed, as by heat staking, into a blob (as shown in Fig. 10) which retains the circuit board assembly in the desired position. Pottin~ material may now be poured into the pocket to a desired fill level 141 after which the material is allowed to cure into a rubbery-like encapsulant for the circuit board and most of the components thereon.
As mentioned in connection with the first mjp/
lU48629 ernbodiment, filling is racilitated by providing one or more openin~s in the clrcuit board to permit the potting material to flow around and beneath the circuit board to avoid unfilled pockets upon curing.
For the lower circuit board assembly 134, which is contained within element 104, there is provided only a single ledge 136 and a single locating pin 138 and boss 140, both of which are located toward the left hand side of pocket 112 as viewed in Fig. 13. The right hand side of the circuit board 134 is both located and supported by virtue of an electrical connector plug assembly 142. As best shown in Figs. 15 and 21, circuit board assembly 134 has the connector plug 142 mounted thereon so that the connector plug extends from the c~rcuit board downwardly through a rectangular opening 144 formed in the lower' wall of housing element 104 within pocket 112. The design of the plastic shell of connector plug assembly 142 is;~such that when the circuit board assembly is being assembled into housing element 104 the plug assembly passes through opening 144 camming a retention tab 146 on the plug shell out Or the way. As the circuit board assembly locates in the intended positlon, the re-tention tab 146 clears the wall of the housing and the inherent resiliency thereof brings the tab into interlocking engagement w~th the housing as shown in Fig. 15. In order to seal around opening 144 between the connectoF plug shell and the housing wall '.~ . ' ,.' :__ _ _ ~
1 1~48~Z9 ¦ a cornpressible sealing gasket 148 ls disposed around the shell l to be compressed between the housing wall and a back-up flange ¦ 150 formed around the shell. The illustrated connector plug ¦ contains four electrical terminal pins 152 which are intended ¦ to effect electrical connection of selected circults on the ¦ circuit board assembly with mating terminal pins in a matlng B l connector plug which mates with plug 142 to~a~rying the circuits associated wlth the terminal plns ~o electrical devices located remotely from houslng 100. With the lower circuit board assembly 134 located within pocket 112, locating pin 138 may be deformed and then potting material may be poured into the pocket to a desired ~ill level 154.
The upper circuit board assembly 132 is provided with an eight terminal pin connector plug assembly 156 which is similar to connector plug assembly 142. However, unlike connector plug 142, connector plug 156 does not pass through an openlng in lts own housing. Rather, connector plug 156 pro~ects in the opposite directlon relative to its mountlng pocket. The connector plug 156 is so located and the two halves of the housin~
are so designed that when the two housing halves are assembled together~ the connector plug 156 pro~ects through a matching opening 158 in the opposite housing halr. This can be seen in detall in Figure 18 where the shell of connector plug assembly 156 passes through opening 158 and a sealing gasket 160 seals bet-~en two 1A the same manner as dld the seal ~8 for the oth t :,'` ' .
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` 1¢~48629 connector plug with respect to its housing. It will be observed that the shell of connector plug 156 lacks any type of interlocking retention tab such as 146 for the connector plug 142. Indeed, it is desirable that the shell of connector plug assembly 156 not have any such retention tab so that the two halves of the housing may be readily separated from each other should such disassembly be necessary. By providing such an arrangement, connection of mating connector plugs is facilitated since both are adjacent.
Furthermore, the arrangement is vertically compact which is desirable in a vehicle engine compartment.
Where the circuit configuration is such that electrical connections are requi;red between the t~o circuit board assemblies such may be readily efEected by providing terminal pins such as indicated at 162 (Fig. 10~ on one of the circuit boards which project above the leyel of the potting material. Leadwires from the other circuit board may then be soldered to the terminal pins 162 at a level above the potting material. Where a circuit element dissi-pates a large amount of heat it is desirable to mount same in the path of air flow through the housing. An example is shown in Fig. 2]. wherein a power transistor 164 and associated heat sink 166 are mounted on upper circuit board assembly 132.
The transistor 164 is attached by means of attachment screws 168 passing through the circuit board to engage tapped holes in the mounting base of the transistor, the heat sink 165 and an insulating spacer 170 being sandwiched therebetween. Heat -generated within the power transistor is dissipated via the transistor casing and heat sink to the circulating air passing through the housing. In this way the maximum temperature of the transistor is maintained within an acceptable limit. Like-wise, as mentioned in connection with the first embodiment, .-:
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1~48f~9 the invention permits the measu~emellt of a~)~ient temperature air by means of a temperature sensing element electrically connected in circuit with one of the circuit boards but being disposed above the level of potting material to be exposed to the ambient air passing througll the circuit board housing.
By way of examp]e, the thermistor 172 in Fig. 21 can sense the temperature of the air and is preferably located upstream of the transistor and heat sink so as to not be influenced by any temperature rise in the air due to the heat dissipation by the transistor and heat sink.
Housing 100 is also designed to accommodate a transducer like the vacuum transducer shown in the first embodiment. However, the arrangément of the second embodiment in this regard offers important advantages over the arrange-ment of the first embodiment. As best seen in ~igs. 6 through 9, a transducer 174 mounts on housing 100 by being mechanically trapped between the two housing halves. ~By way oi example, transducer 174 may be a vacuum-actuated variable inductance type as disclosed and claimed in copending appli-cation Serial No. 243,475, filing date January 13, 1976. This type of transducer comprises a generally cylindrical vacuum actuator portion 176 and a smaller cylindrical coil portion 178. The lower housing element 104 immediately adjacent the left hand side of pocket 112 as viewed in Fig. 13 contains a receptacle 180 into which the transducer 174 is inserted.
; ~eceptacle 180 is generally semi-cylindrically shaped and com-prises an inner portion 182 whlch is adapted to receive the coil portion 178 of the transducer, and an enlarged outer portion 184 which is adapted to accommodate the larger diameter of the vacuum actuator portion 176 of the transducer. A groove 186 is formed in the outer portion 184 and receives the lowe~
portion of a flange 188 provided on the transducer adjacent ~he ' mjp/
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` 1¢~48~i29 juncture of the Yacuum actuator portion and the coil portion.
As best seen in Fig. 14, the cross section of receptacle 180, and its severRl portions 182, 184, and 186, is such that the surfaces thereof lie on respective truly semi-cylindrical surfaces about and below an axial centerline 189. Above the centerline 189, the respective surface portions continue as spaced parallel walls extending upwardly from the truly semi-cylindrical portions. Hence, the receptacle 180 and its portions 182, 184 and 186 may be considered as U-shaped as viewed in ~'ig. 14. The flange 188 on the transducer has its lower portion designed to complement the U-shaped groove 186.
This shape can be seen in Fig. 9. This construction permits transducer 174 to be readily inserted into receptacle 180 so that the U-shaped flange 188 fits within and registers with the U-shaped groove 186. When so inserted the transducer is correctly located both circumferentially and axially, and relative rotation between housing element 104 and the trans-! ducer 174 about the centerline 189 is precluded. Thus, the transducer mounting arrangemellt advRntageously provides a self-locating, anti-rotation feature, and furthermore eliminates the need for any separate mechRnicRl fasteners. The upper housing element 102 is designed with a circularly contoured segment 190 and a circularly contoured groove 192 formed therein to engage the circularly contoured upper portion of the transducer flange 188 when the two housing halves are --assembled. It will be observed that when the two housing halves are assembled, the portions of the surface 110 immediately adjacent the ends of groove 192 overlie the tops of the lower U-shaped portions of flange 188 thereby also precluding rotation of the trRnsducer. Two electrical termi-nals 194, 196 at the inner end of the transducer, are connect-ed with the lower circuit board assem~]y 13~ by means of lead mjp/
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1~48629 wires 19~, 200 ~hich lead from the termina~s througll suitable passageways formed in housing element 104. This transducer mounting and connection arrangement enhances assembly and serviceability. Also, the flange and groove seals between the housing and the transducer to prevent the intrusion of contam-inants.
In the assembled unit it is desirable to adhere a sealing gasket 202 on the concave inner face of housing 100 as shown in Fig. 22. The sealing gasket includes suitable cut-outs 204, 206 for the air scoop and the air discharge outlet respectively as well as cutaways 20~ for the attaching holes via which the housing is attached to the air cleaner housing 14. As can be seen in Fig. 6, housing 100 is attached to air cleaner housing 14 by means of attachment screws 210 which pass through suitable holes in the side wall of the air filter housing to threadly engage matching holes provided in housing -100. This permits the housing to be conveniently attached to and removed from the air filter housing. With the provision of the sealing gasket and the design of the two housing elements, the interior of the unit is adequately sealed so that the only exterior communication is via the air inlet and outlet openings.
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Claims (29)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an engine having an induction air intake system including an air filter housing having a cylindrical side wall, the combination with said air filter housing of:
an electronic circuit board housing containing at least one electronic circuit board assembly therein;
means mounting said circuit board housing on the side wall of said air filter housing; and means communicating the interiors of said two housings to provide air circulation within said circuit board housing when the engine is operated.
an electronic circuit board housing containing at least one electronic circuit board assembly therein;
means mounting said circuit board housing on the side wall of said air filter housing; and means communicating the interiors of said two housings to provide air circulation within said circuit board housing when the engine is operated.
2. The combination of claim 1 wherein said last-mentioned means includes an air intake scoop disposed within said air filter housing via which air passes from said air filter housing into said circuit board housing when the engine is operated.
3. The combination of claim 2 including a diverter disposed in said air filter housing in the vicinity of said air intake scoop to facilitate air flow into said scoop.
4. The combination of claim 1 wherein the dimension of said circuit board housing, in the direction of the axial dimension of said air filter housing side wall, is less than the axial dimension of said air filter housing side wall.
5. The combination of Claim 1 wherein said circuit board housing comprises:
first and second housing elements detachably secured together to form said housing;
each of said housing elements comprising a circuit-board-assembly-receiving pocket interior of the housing;
an electronic circuit board assembly in each one of said pockets; and potting means for potting each circuit board assembly in its respective pocket.
first and second housing elements detachably secured together to form said housing;
each of said housing elements comprising a circuit-board-assembly-receiving pocket interior of the housing;
an electronic circuit board assembly in each one of said pockets; and potting means for potting each circuit board assembly in its respective pocket.
6. The combination of Claim 1 including a transducer device mounted on said housing separate from said at least one electronic circuit board assembly and lead wires connecting said transducer device with circuitry on said at least one electronic circuit board assembly.
7. In an engine having an induction air intake system including an air filter housing having a cylindrical side wall, the combination with said air filter housing of:
an electronic circuit board housing containing an electronic circuit board assembly therein;
means mounting said circuit board housing on said air filter housing;
means communicating the interiors of said two housings to provide air circulation within said circuit board housing when the engine is operated; and an electronic circuit element mounted on said electronic circuit board assembly but disposed in the path of air circulation in said circuit board housing.
an electronic circuit board housing containing an electronic circuit board assembly therein;
means mounting said circuit board housing on said air filter housing;
means communicating the interiors of said two housings to provide air circulation within said circuit board housing when the engine is operated; and an electronic circuit element mounted on said electronic circuit board assembly but disposed in the path of air circulation in said circuit board housing.
8. The combination of Claim 7 wherein said circuit element is a temperature-sensing device.
9. The combination of Claim 7 wherein said element is a power dissipating device.
10. The combination of Claim 7 including a second circuit element on said circuit board disposed in the path of air flow between the two housings, one of said elements being located upstream of the other.
11. In an engine powered vehicle having an induction air intake system for the engine including an air filter housing having a cylindrical side wall and an intake snorkel projecting therefrom and including electronic en-gine control circuitry, the improvement comprising:
means mounting at least portions of said control circuitry on a circuit board;
a circuit board mounting housing containing said circuit board therein;
means mounting said circuit board mounting housing on said air filter housing circumferentially of said snorkel;
and means communicating the interiors of said two housings to provide air circulation within said circuit board mounting housing when the engine is operated.
means mounting at least portions of said control circuitry on a circuit board;
a circuit board mounting housing containing said circuit board therein;
means mounting said circuit board mounting housing on said air filter housing circumferentially of said snorkel;
and means communicating the interiors of said two housings to provide air circulation within said circuit board mounting housing when the engine is operated.
12. The improvement of claim 11 wherein said circuit board is disposed in a potting material within said circuit board mounting housing.
13. The improvement defined in claim 12 wherein an electronic circuit component is connected electrically with circuitry on said board and is disposed physically exterior-ly of said potting material and exposed to air circulation within said mounting housing.
14. The improvement defined in claim 11 wherein a connector plug is provided on said circuit board and extends through an opening in said mounting housing.
15. The improvement defined in claim 11 wherein the interiors of the two housings are communicated via openings in the side wall of said air filter housing.
16. The improvement defined in claim 11 wherein said circuit board mounting housing mounts on the side wall of said air filter housing.
17. The improvement defined in claim 11 wherein the interior of said mounting housing is concave in shape and faces radially inwardly of said air filter housing.
18. The improvement defined in claim 11 including a transducer for said circuitry mounted on said mounting housing.
19. In an engine comprising induction air intake structure including an air filter housing and comprising electronic, engine control circuitry, the improvement comprising:
a control circuit housing adapted to contain electronic control circuitry;
means mounting at least a portion of said elec-tronic engine control circuitry within said control circuit housing;
means mounting said control circuit housing on said air filter housing; and means communicating said two housings to provide air circulation therebetween when the engine is operated.
a control circuit housing adapted to contain electronic control circuitry;
means mounting at least a portion of said elec-tronic engine control circuitry within said control circuit housing;
means mounting said control circuit housing on said air filter housing; and means communicating said two housings to provide air circulation therebetween when the engine is operated.
20. The improvement defined in claim 19 wherein said portion of said electronic engine control circuitry within said control circuit housing mounts on a circuit board, and said circuit board and some of the circuitry thereon are encased within a potting material inside said control circuit housing, said portion of said electronic engine control circuitry including a circuit element external of said potting material and in the path of air circulation between said two housings.
21. The improvement defined in claim 20 wherein said circuit element is a power-dissipating device.
22. The improvement defined in claim 20 wherein said circuit element is a temperature-sensitive device.
23. The improvement defined in claim 19 wherein said means communicating said two housings comprises separate inlet and outlet means.
24. The improvement defined in claim 19 wherein said air filter housing has a cylindrical side wall and said control circuit housing is disposed on said side wall, said means communicating said two housings comprising openings in said side wall and said control circuit housing.
25. In an engine comprising induction air intake structure via which air is inducted into the engine and comprising electronic engine control circuitry, the improve-ment comprising:
means mounting at least a portion of said engine control circuitry on a circuit board;
a housing within which said circuit board and said control circuitry portion thereon are contained; and means communicating said air intake structure and said housing comprising means via which air can enter said housing from said air intake structure and means via which air can exit said housing to said air intake structure.
means mounting at least a portion of said engine control circuitry on a circuit board;
a housing within which said circuit board and said control circuitry portion thereon are contained; and means communicating said air intake structure and said housing comprising means via which air can enter said housing from said air intake structure and means via which air can exit said housing to said air intake structure.
26. The improvement defined in claim 25 wherein said induction air intake structure comprises an air filter housing and both said housings are mounted together.
27. The improvement defined in claim 25 wherein said housing has a wall thereof disposed against a wall of said induction air intake structure, said means communicating said air intake structure and said housing providing communica-tion through openings in said walls.
28. The improvement defined in claim 27 wherein communica-tion between said two housings is via separate inlet and outlet openings in said walls.
29. The improvement defined in claim 25 wherein some of said control circuitry portion is encased within a potting material inside said housing and said control circuitry portion includes a circuit element external of said potting material and disposed in the path of air passing through said housing.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US57054075A | 1975-04-22 | 1975-04-22 | |
| US58719375A | 1975-06-13 | 1975-06-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1048629A true CA1048629A (en) | 1979-02-13 |
Family
ID=27075342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA76243476A Expired CA1048629A (en) | 1975-04-22 | 1976-01-13 | Housing for mounting electronic circuit boards on an engine air filter housing |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1048629A (en) |
| GB (1) | GB1510436A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3703073A1 (en) * | 1987-02-03 | 1988-08-11 | Bosch Gmbh Robert | FUEL INJECTION PUMP |
| US5035637A (en) * | 1990-05-04 | 1991-07-30 | Navistar International Transportation Corp. | Engine valve cover gasket with electrical bridge |
| GB9823556D0 (en) * | 1998-10-28 | 1998-12-23 | Rover Group | A motor vehicle |
-
1976
- 1976-01-13 CA CA76243476A patent/CA1048629A/en not_active Expired
- 1976-04-07 GB GB1412276A patent/GB1510436A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1510436A (en) | 1978-05-10 |
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