GB2221349A - A solenoid assembly and fluid control valve - Google Patents

Abstract

A solenoid assembly for actuating a fluid control valve in an electronic automatic transmission controller comprises an energising coil 82 defining a bore 85 in which are mounted a pole piece 94 and a moving armature 96 whose flat confronting faces define a first gap 136, the armature also having a part-conical face 106 defining a second gap with a face 108 of a flux collector plate 66 so that the attraction forces acting on the armature at the respective gaps when the coil is energised reinforce each other. A valve member 128 normally closes a passage 129 under the action of a spring 104 but is freed to close a passage 127 when the solenoid is energised. <IMAGE>

Description

A SOLENOID ASSEMBLY AND FLUID CONTROL VALVE ASSEMBLY INCLUDING SUCH SOLENOID ASSEMBLY This invention relates to a control assembly particularly suited for use in a fluid control device, and particularly in such a device adapted for controlling operation of a motor vehicle automatic transmission.

In the past, automatic transmissions used in motor vehicles were typically controlled through fluidic control systems incorporating numerous piston and cylinder assemblies.

Although such devices operate satisfactorily, they have several drawbacks including high cost attributable to the high precision necessary in machining the components and the necessity of providing and assembling numerous components.

Further, such systems are restricted in their operational capabilities. Modern motor vehicles are incorporating increasing numbers of electronically controlled subsystems and particular attention is presently being directed toward designing electronically controlled automatic transmission controllers.

A number of significant design challenges are presented in designing an electronically operated transmission controller. Due to the fact that such controllers would typically be located within the oil sump region of the automatic transmission, the overall height of the assembly must be limited in order to provide acceptable vehicle ground clearance and to otherwise facilitate packaging of the various transmission components. It is further desirable to provide such a device which is resistant to tampering to prevent unqualified individuals from undertaking servicing operations.

As with any device intended for mass production, manufacturing cost is of extreme importance. Cost advantages can be obtained through devices which are capable of being assembled using automatic machinery. Furthermore, cost savings are realised when the components of the system are not required to be manufactured with high dimensional precision. Accordingly, it is desirable to provide a transmission controller capable of being assembled automatically and which is made from components having minimal tolerance requirements.

The present invention is divided from our copending Patent Application No 87 05764 (Serial No 2 188 993) which has a disclosure similar to that of the present application and in which we claim a transmission controller assembly adapted for use with a transmission having a portion thereof formed with a mounting surface and fluid ducts of predetermined configuration opening through said mounting surface, said assembly comprising: a manifold having fluid flow ports and adapted to be detachably fastened to said transmission with a first side thereof on said mounting surface; a plurality of solenoid operated valve means having inlet and outlet ports at one end and electrical terminals at the other end thereof and solenoid operated valve means adapted to control the flow of fluid in respective ones of said fluid ducts in response to electrical signals applied to said electrical terminals; mounting means supporting said solenoid valve means on said manifold and positioning said valve means with said inlet and outlet ports exposed to said fluid flow ports of said manifold for communication with said fluid ducts in use of the assembly mounted on a transmission; holding means fastening said solenoid operated valve means to said manifold; and a circuit board surmounting said manifold, said circuit board having a first surface facing away from said manifold and soldering pads on said first surface, said solenoid electrical terminals extending through said board and being positioned adjacent said soldering pads.

Thus there is disclosed herein the use of solenoid operated valves for controlling flow of transmission fluid which are preferably operated by a digital control system.

The solenoid valves are mounted as a subassembly on a common manifold; the arrangement is such that the subassembly can be mounted as a unit to the transmission case of a motor vehicle.

The unitary subassembly construction facilitates manufacture of the subassembly and, accordingly, minimises cost. To this end, the components of the subassembly are correlated in a manner that facilitates automation of the various operations required in the manufacture of the subassembly. Moreover, the components of the subassembly are assembled in such a way as to prevent tampering by persons who might not know the essential values and requirements of the components that might require replacement, and as a result, unjustly expose the original manufacturer of the transmission or of the associated vehicle to warranty obligations and expenses.In this connection, it is desirable, both from the standpoint of the manufacturer and of the customer, that the subassembly be replaced as a whole if service of any component thereof is necessary or desirable and that the subassembly be returned to the manufacturer or supplier for proper servicing.

Another advantage of the controller assembly is that it permits the maximum use of moulded plastic parts and this has the further advantage of reducing or minimising the cost of manufacture. The manifold plate on which the solenoid valves are mounted is preferably made of metal while some of the valve assembly components of the solenoid valves ideally are made of plastic by conventional injection moulding processes. In practice, flow of transmission fluid through the flow ducts in the transmission is controlled by solenoid operated valves which are mounted on the side of the manifold opposite the surface which mounts to the transmission. In practice,the manifold is mounted in the pan or oil sump at the bottom of the transmission with the manifold seated upwardly against and bolted or otherwise fastened to the transmission case at the top of the sump.In this environment, the solenoid valves extend downwardly in to the sump and are submerged or at least partially submerged in transmission fluid.

A requirement for a low vertical height of the controller assembly imposes extreme demands in the design of the solenoid operated valves since it is difficult to design high force output valves which are also very compact.

Additionally, since the device is intended to control the flow of fluids, the elements must be capable of handling the desired pressures and flow rates of such fluid. These design parameters are achieved by the solenoid assembly of the present invention through the use of high force output solenoids.

According to the preesnt invention, there is provided a solenoid assembly comprising: an energisation coil defining a longitudinal bore, a pole means defining a first surface disposed in said bore, a movable armature disposed in said bore and adapted to translate in said bore in response to energisation of said coil, said armature defining a second surface which faces said first surface of said pole means, said first and second surfaces defining a first working air gap across which magnetic fields are transferred thereby generating an attracting force between said pole means and said armature urging said armature to move in said bore, said armature further defining a conical shaped third surface, a flux collector plate defining a conical shaped fourth surface which faces said armature third surface, and said third and fourth surfaces defining a second working air gap across which magnetic fields are transferred thereby generating an attracting force between said flux collector plate and said armature, said attracting force having a component which acts in the direction of movement of said armature, thereby augmenting the attracting force provided across said first air gap.

One described embodiment of such a solenoid operated valve includes a dual working air gap feature which enables high force output to be provided with low solenoid stacking height. Packaging space reductions of the controller assembly are further realised by mounting a printed circuit board which contains the connection points for the various solenoids and connectors directly onto one end of the solenoid valve assemblies. Cost reductions attributable to reductions in tolerance requirements are achieved by employing a system for mounting the solenoid operated valves against the associated manifold using a bracket plate having deflectable spring fingers which resiliently bias the valves into their mounting ports.Excellent fluid flow characteristics are provided by designing the valve elements of the solenoid operated valves such that they provide tapered orifices which reduce the tendency for high frequency oscillations and eddies from being generated ruing fluid flow through the valve and increase cold temperature flow by reducing viscous losses.

The present invention will be further described, by way of example, with reference to the accompanying drawings, wherein: - Figure 1 is a side elevational view of an automatic transmission controller assembly embodying the invention of the parent application referred to above, showing the assembly completely assembled; Figure 2 is a bottom view of the manifold; Figure 3 is a cross-sectional view through an ON/OFF solenoid valve assemblies which embody the present assembly; Figure 4 is a partial sectional view taken along line 4-4 of Figure 3 showing the assembly of the housing and flux collector components; Figure 5 is a cross-sectional view through a variable force solenoid valve assembly; Figure 6 is a bottom view of the solenoid valve assembly mounting bracket;; Figure 7 is a bottom view of the assembly of the manifold, solenoid valves and bracket shown in Figures 2 and 6; Figure 8 is a cross-sectional view taken along line 8-8 of Figure 1 showing the internal details of an electrical connector; and Figure 9 is a top view of the transmission controller assembly particularly showing the circuit board component as installed on the assembly.

An electronic automatic transmission controller is shown fully assembled in Figure 1 and is generally designated there by reference numeral 10. Controller 10 principally comprises manifold 12, a plurality of ON/OFF solenoid valve assemblies 14, variable force solenoid valve assembly 16 (optional), bracket 17, PC board 18, and electrical connector 20. In use, automatic transmission controller 10 would be affixed to an automatic transmission device and disposed in the oil sump chamber of such a transmission. The normal mounting orientation of controller 10 is shown in Figure 1 with PC board 18 or protective cover 19 defining the lowermost portion of the controller.In operation, solenoid assemblies 14,16 would receive electrical signal inputs from a remote electronic controller device which would cause the valve assemblies to change fluid pressure within various flow channels of the transmission to thereby cause the transmission to undergo shifting changes, etc. The associated transmission structure would be configured to permit electrical connector 20 to be exposed to the exterior of the transmission to permit an associated electrical connector to be attached thereto.

Figure 2 provides an illustration of some of the details of Manifold 12. Manifold 12 is preferably formed from a metal through die casting and/or machining processes. Manifold 12 has a loser surface 22 defining a plurality of ON/OFF solenoid valve assembly mounting ports 24.

Figure 2 hows four of such ports although other numbers may be used, depending on the particular application. Each of ports 24 defines a central bore 34, an annular surface 36 concentrically encircling bore 34, and flow port 38. An additional planar surface 40 surrounds the ports and is displaced from the plane of lower surface 22. Each of ports 24 further defines a peir of peds 44. Mounting port 32 is configured to receive variable force solenoid valve assembly 16. FDrt 32 for variable force solenoid valve assanbly 16 similarly includes a central port 46, flow port 47, and con concentric surfaces 48 and 50.The solenoid valve ports 34 and 38 ccumunicate with fluid channels in the wain transmission case. Ports 46 and 47 wtunoicate with various fluid flow channels defined by the side of manifold 12 opposite surface 22. The manifold flow channels wrrnunicate with associate flow ducts in the automatic tranamission (not shown).

Manifold bore 52 provides a mounting orifice for electrical connector 20.

Manifold 12 further includes a peir of upstanding posts 58 having central blind threaded bores and a plurality of upstanding rounting posts 54 located around the peripheral edges of the manifold edges. Posts 54 have a shorter axial length than posts 58 and define bores 55 which pass through the manifold, and include blind threaded bores 57.

Figure 3 provides a detailed view of the internal components of CIVOFF solenoid valve assembly 14. CE/OFF solenoid assembly 14 is enclosed ty a generally cylindrical housing 60 having a lower surface with a pair of opposed extending tabs 62 and 64. Flux collector plate 66 is made from a magnetic material and is generally circular with a central bore 68 and a pair of extending flange portions 70 and 72. As best shown in Figure 4, flange portions 70 and 72 further define slots 74 and 76. A peir of recessed notches 78 and 80 extend from slots 74 and 76 in a radially outward direction as shown in Figures 3 and 4.When assembled, housing 60 is located such that tabs 62 and 64 are inserted through slots 74 and 76.

Thereafter, tabs 62 and 64 are deformed in a radially outward direction to interlockingly engage with flux collector plate 66. The remaining portions of the lower circular edge of housing 60 are deformed in a radially inward direction as best shown in Figure 3. With this construction, the lower surface of flux collector plate 66 establishes the positioning of solenoid valve assembly 14 with respect to manifold 12. Such a design has advantages over alternate designs which anploy the lower surface of the housing for establishing the positioning of the solenoid valve assatibly.

Such alternate designs would require precise machining of the lower edge of housing 60 in order to insure accurate positioning of the solenoid valves.

Disposed within housing 60 is a generally toroidal-shaped coil assembly 82 which includes spool-shaped bobbin 84 having bore 85 along its longitudinal axis and wire coil 86. Bobbin 84 has a peir of uçERsunding terminal posts 88 (one shown) which are electrically connected to coil 86.

The end of valve assembly 14 opposite manifold 12 is enclosed by flux collector 90 having central bore 92. Pole pierce 94 is press fit into bore 92 such that it is disposed into a portion of bobbin bore 85 and remains in the stationary position following assembly.

Armature 96 is the moving actuating element within valve assembly 14. As shown, armature 96 has a generally flared end 98 and an opposite end defining a blind bore 102 with spring 104 disposed therein. Armature flared end 98 defines a conical surface 106 which is spaced frat a correspondingly shaped conical surface 108 of flux collector Elate 66.

Aznature flared and 98 further has a centrally d-sed projecting pin 110.

Control of fluid flow between manifold ports 34 and 38 is accomplished through the operation of valve assembly 112 which is actuated by armature 96. Valve assembly 112 includes valve body 114 which defines tio cylindrical surfaces 116 and 118 with annular seal grooves 120 and 122.

Valve body 114 further forms a central tapered orifice 124. Exhaust plate 134 is installed within valve body 114 to define internal chamber 126 which confines valve ball 128. Chamber 126 opens to a pair of ports 127 and 129 formed by exhaust plate 134 and valve body 114, respectively. Valve ball 128 is movable within chamber 126 to selectively control fluid flow through ports 1Z7 and 129. Valve body 114 has one or wore radially extending orifices 130 communicating with cham umber 126.

Operation of CE/OrP solenoid valve assembly 14 will ncs be explained with particular reference to Figure 3. Solenoid valve assembly 14 is energized ty passing electrical current through coil 86. The resulting magnetic field is transmitted through pole piece 94, armature 96, flux collector plate 66, housing 60 and flux collector 90. When this occurs, the surfaces defining the air gaps within the magnetic circuit are caused to be attracted to one another due to their opposite magnetic poles.

Armature 96 and the correspondirs components define two separate working air gaps which generate forces urging armature 96 to translate within bore 85. Air gap 136 is defined ty the interface between armature 96 and pole pierce 94. In accordance with conventional practices, the other air gap which would be necessary ssary to transfer magnetic fields to armature 96 would be comprised of a radially extending gap such as gap 138 defined ty separated cylindrical surfaces of armature 96 and bore 68 of flux collector plate 66.Such radially extending air gaps do not produce an attracting force which urges armature 96 to move, but are ordinarily necessary in order to provide a conduction path for the magnetic fields generated ty current flow through coil 86. Ebwever, these inventors have found that ty designing a second air gap having surfaces which are not truly cylindrical, additional attracting forces can be generated which augment the force applied on armature 96, thus enabling higher force output solenoids to be provided.

The tapered surfaces 106 and 108 define such a secondary air gap 140. Lines of force which act in a direction generally perpendicular to these surfaces have a component in the direction of linear movement of armature 96, and therefore add to the useful operating for exerted on the armature. Surfaces 106 and 108 are tapered such that the distance between than does not increase as much as the distance of linear mo tion of armature 96. By limiting such separation distance, attracting for can be developed over long armature travel.

When using such non-cylindrical air gaps, it is desirable to eliminate short cylindrical air gaps which could result in magnetic losses in the system.

A plurality of mall local bumps or projections 142 may be provided on either of the surfaces of either air gap 136 or 140 (as shown). During operation of valve assembly 14, these projections 142 would be designed to make direct contact with the oorresponding opposing surface of that air gap. By permitting such contact, the air gap separation distance for the remaining surfaces can be accurately established. In solenoid design, it is usually necessary to control the minion air gap distance since the attraction force between the surfaces of an air gap for a given current flow increases exponentially with decreased air gap distance.When separation distances become extremely small, a change in state of the solenoid valve assembly following de-anergization beaches less reliable if any residual magnetisti is present when no electrical current is flowing through the coil. Although projections 142 drake contact with the corresponding air gap surface and would consequently constitute a very small air gap, their areas are very small, thus limiting the total forces which can be applied by these features.

Figure 3 illustrates solenoid valve assembly 14 in a de-energized state. In this condition, the biasing force exerted by spring 104 through armature 96 urges valve ball 128 into sealing engagement with port 129 which blocks the flow of fluid between that port and orifice 130. In this position, fluid communication is estaIished between ports 127 and 13O, thus providing a pressure vent for the fluid circuit associated with port 38 of manifold 12. Spring 104 is selected and preloaded to exert a sufficient force to prevent unseating of ball 128 when orifice 124 is exposed to given maximum fluid pressure, far aole 130 psi (10.76 bar). Wi n current is caused to flow through coil 86, thus energizing the solenoid assembly, armature 96 is attracted in a direction toward pole piece 94 to the degree that the force exerted by spring 104 is overcome, enabling the armature to translate upwardly. Such movement of armature 96 permits ball 128 to be unseated from port 129 and instead becomes seated against port 127 due to the pressure of fluid flowing through port 129. In this aondition, fluid ccn::=nication is established between tapered orifice 124 and radially extending bores 130.

Figure 5 provides a detailed illustration of the internal working components of variable force solenoid valve assembly 16. Variable force solenoid valve assembly 16 is enclosed by bDusing 144 baving a generally closed end 146 with central bore 148 and terminal bore 149. The opposite end of housing 144 is opened and defines annular shoulder 150, such that the housing is slightly flared at that end. Disposed within housing 144 is coil assembly 152 comprised of coil 153 and spool-shaped bobbin 154.

Coil 153 is electrically connected to a pair of upstanding terminals 155 (one shown) which extend through housing bore 149. flux collector 156 is positioned at one end of coil assembly 152 and forms a central threaded bore 157. At the opposite end of coil assembly 152, flux collector 158 is provided with central bore 160 and external annular groove 161. Following assembly, the lower edge of housing 144 is deflected inwardly to interlock with flux collector 156. Coil assembly 152 defines a central bore 196.

l9belar insert 162 is disposed within the coil assembly bore and has a radially outwardly extending end 163. Armature assembly 164 is positioned within the coil assembled bore such that it can translate therein.

Armature assembly 164 is a composite structure made from tube portion 166 which has an open end and a generally closed opposite end having a central bore 167. Armature insert 168 is a generally disc shaped member having an uS mding central pin 169 and has an outer diameter which provides an interference fit with the inside diameter of tube 166. Energization of coil 153 produces a force on armature assembly 168 urging it to move in an upward direction, with reference to the orientation of the elements shown in Pigure 5.This action occurs through a magnetic conduction path in which magnetic fields are transferred through flux collector 156, armature assembly 164, flux collector 158 and housing 144, thereto providing a working air gap between the end of tube 166 and flux collector plate 156.

Armature assembly 164 is guided to remain in a desired aligned positioning within bore 196 of tubular insert 162 through the guiding action provided by guide bushings 170 ard 171, which are made of a non-magnetic material which is stable over a wide tanperature range. Guide bushing 170 is maintained in position through clamping engagement between tube 162 and spacer guide 172. Guide bushings 170 and 171 provide a low friction neans of supporting armature assembly 164 for axial movement without employing costly precision linear ball bearings.

Variable force solenoid valve assembly 16 includes a mechanism for providing an adjustable compliant loading onto armature passably 164 which opposes forces Imposed through energization of coil 153. This machinism includes coil spring 173 disposed within tube 166 which rests on spring post 174. be opposite end of coil spring 173 rests on spring seat 175 which is positioned on headed pin 176. Beaded pin 176 includes a portion having a threaded external surface which threadingly engages adjuster sleeve 177, which in turn is threaded into threaded bore 157 of flux collector 156.By changing the positioning of pin 176, a variation in the biasing force exerted ty spring 173 is provided ty changing the mount of compression of the spring. Adjustment sleeve 177, on the other band, provides a stop surface which permits control over the sninimun, distance of the air gap between armature tube 166 and flux collector 156.

As previously explained, direct contact or excessively small air gap distances should be avoided since they can cause great difficulty in controlling forces acting on the armature.

The fluid oontrol components associated with variable force solenoid 16 are disposed within manifold solenoid nbunting port 32.

Variable force solenoid 16 is provided with controller 10 to enable control over fluid pressures to be provided in response to d current input signal to coil 153. such control is achieved w electively reducing the pressure of fluid at inlet pressure to a control pressure 6 restricting fluid flow and through venting fluid to the transnission sump. Valve assembly 178 is disposed within port 46, and is primarily composed of valve body 179, spool valve 180, and inserts 181 and 182.Valve body 179 defines a plurality of radially extending inlet ports 184 which wmnonicate from the external surface of valve body 179 to internal chanber 185 which are exposed to fluid at inlet pressure. Another set of radially extending passages 186 are provided which conduct fluid at control pressure. The external end of spool valve head 187 is exposed to control pressure through passages 188. Cap 197 encloses the space at the lower and of valve assembly 178. The opposite end of spool valve 180 defines spool valve head 189 which res within central bore 190 of the valve body. Pin 169 of armature insert 168 abuts spool valve head 189 which enables pin 169 to trarmit forces against head 189 while enabling valve 180 and armature assanbly 164 to be decoupled so that any :iiMiigeeant in their longitudinal axles will not cause the oxponents to bind as they translate. The external surface of valve body 179 includes grooves 191 and 192 having seals 193 and 194 disposed therein. flux collector 156 defines groove 159 having seal 165 disposed therein.This arranganent provides separated fluid passages wherein inlet pressure is provided via inlet port 184 and oontrol pressure is provided through passages 186 and 188 and through bore 47 of the manifold. fluid can be vented from the unit into the sump pusage through port 195.

Operation of variable force solenoid valve 16 will row be explained with reference to Figure 5. fluid at inlet pressure is provided through port 184 and into chamber 185. mis fluid is permitted to flow along spool valve 180, through bore 190, passages 186 and 188, and therefore becomes exposed to the lower end of bead 187. mis action causes a resultant force to act on spool element 186 which urges it in an upward direction to a point where the force exerted by spring 173 and the fluid pressure acting on head 187 are balanced.Preferably, in the absence of current flow through coil 153, such force balancing causes spool valve 180 to be displaced upwardly to impose a fluid flow restriction between valve head 187 and bore 190. This restriction, together with fluid leakage which is intentionally permitted between head 189 and bore 190 to the sump (at about atmospheric pressure) will provide a regulated control pressure at some predetermined level, for example, 90 psi (6.20 bar) when the inlet pressure is about 100 psi (6.89 bar). modulation over the cmtId me is prpovideb by selectively bl energising @@il cr::l 153.A gi leuel of current through the coil will cause a magnetic force to be applied onto armature assembly 164 urging it in an upward direction, which is opposed by the force imposed by spring 173 aided by the pressure force on head 187. mis action has the effect of rmrbalancing the above-described equilibrium.The resultant force causes armature assembly 164 and spool valve 180 to Move in an upward direction and seek 6 new equilibrium condition. such action further restricts the flow passage between head 187 and bore 190 and sitareously reduces the restriction of flow between fluid control pressure and the sunp between head 189 and port 190 since the extent of overlap between the bore and head 189 beoes reduced.

Acxrdingly, controlled energization of coil 153 enables the pressure of the control pressure to be reduced from the norrtnergized equilibrium control pressure in a desired manner.

During initial asnbly and calibration, fluid at inlet pressure is applied through port 184 to the terminal end of head 187 and beaded pin 176 is rotated until the compliant load provided by spring 173 produces a desired control pressure. Nest, a voltage signal is applied to coil 153 to provide a predetermined current and the control pressure is monitored as adjustment sleeve 176 is rotated to produce a predetermined control pressure which occurs when a desired air gap distance exists between flux collector 156 and armature assembly 164.

During ashy, ON/OFF solenoid valve assemblies 14 and variable force solenoid assembly 16 are inserted into punting ports 24 ard 32 of @nifold 12. Bracket 17 is used to snort the solenoid valve assemblies.

cricket 17 is best can with reference to Figure 6 and includes a plurality Cf tolcs 204 and 205 for manifold bores 55 and 57, respectively.

Apertures 206 provide clearance for posts 58. Bracket 17 defines four solenoid valve assembly receiving areas 208 for clearance for ON/OFF solenoid valve assemblies 14, ard includes a pair of diametrically opposed solenoid valve retaining fingers 210 which become positioned over manifold pads 44. The end portions of retaining fingers 210 are deformed downwardly to define tabs 212. Bracket 17 features another valve retaining area 214 for variable force solenoid valve 16. Retaining area 214 is formed by an elongated slot 216. Variable force solenoid valve 16 is loaded into slot 216 by sliding valve groove 161 into the slot.

Figure 7 shows the previously described components assembled. Solenoid valve assemblies 14 are loaded into the mounting ports 24 and bracket 17 is dropped over them.

If variable force solenoid 16 is to be used, it is loaded into bracket slot 216. One or more fasteners are provided which pas through bracket holes 204 and engage threaded manifold bores 57 to retain the subassembly together.

Preferably, such fasteners would be of the so-called "break-away" or "torque-off" variety, having a driving head which shears apart from the remainder of the fastener when a given applied torque is reached, thus preventing the fastener from being easily removed later. As previously explained, it is desirable to prevent unauthorised servicing of this device, and the use of such fasteners effectively discourages individuals without special equipment from attempting component repairs themselves.

When controller 10 is mounted to the associated transmission structure, threaded fasteners are disposed through bracket holes 204 and manifold bores 55. The use of such fasteners securely clamps together bracket 17 and manifold 12. Bracket retaining fingers 212 are designed to deflect slightly such that they exert a constant clamping force on the solenoid valve assemblies, thus maintaining them in their installed position precluding relative motion with manifold 12 which would tend to wear the seal elements associated with the valve assemblies. Spring fingers 212 may be designed to permanently deform to eliminate high tolerance requirements and to guarantee hold down force simultaneously at all points. Raised areas 244 adjacent bracket slot 216 provide an interference fit with groove 161 to control vibration and pressure induced movement of solenoid valve 16 which would tend to wear seals 165 and 194.

Now with reference to Figure 8, electrical connector 20 is shown in detail. Connector 20 preferably comprises a tubular outer sleeve 222 which has a reduced diameter section 224 exterior shoulder 226. Sleeve section 224 is dimensioned to be inserted into manifold bore 52.

The inside surface of sleeve 222 includes a radially outwardly extending annular groove 228. In a preferred construction of connector 20, sleeve 222 is loaded into an injection moulding die and a plurality of conductors 230 are disposed therein. Next, flowable resin material is injected into sleeve 222 to define conductor body 232.

Once moulded, conductor body 232 has conductors 230 projecting from one end and forms a male connector receiving cavity 218. Groove 228 ensures that the conductor body 232 interlockingly engages sleeve 222. Once loaded into bore 52, the extending post portions 236 of connector 20 lie in the plane of the end surfaces of solenoid valve assembly 14,16. The above-described configuration permits PC board 18 to be loaded onto that plane such that all the electrical terminals extend through holes 239 in the PC board. In this manner, PC board 18 can be automatically soldered using wave soldering techniques which involve passing the assembly with the PC board faced in a downward orientation over a wave of molten solder which adheres to the exposed metal surface of the PC board and terminals.

PC board 18 is illustrated in simplified form in Figure 9 which shows holes in the board for terminals of the solenoid valves 14,16 and connector 20. In practice, board 18 would have a conductive layer which is etched in a manner to provide the desired connections between the various terminals. In addition, PC board 18 may -further provide conduction paths and mounting provisions for diodes for each solenoid valve which are used to suppress solenoid induced voltage spikes.

In accordance with another feature, loading and soldering of PC board 18 onto the assembly is facilitated.

If the holes through PC board 18 for electrical terminals 88 are small in relation to the cross-sectional area of the terminals, precise positioning of the components is necessary in order to load the PC board in place.

Unfortunately, it is ordinarily necessary to avoid large gaps between a circuit board soldering surfaces and the associated electrical terminals in order to ensure electrically and mechanically secure connections. However, as shown in Figures 3 and 5, electrical terminals 88 and 155 of solenoid valve assemblies 14 and 16 may be conformed in a tubular shape. The outer diameter of the tube 88 is significantly smaller than the inside diameter of bores 238 in PC board 18. Such clearance facilitates fabrication by reducing the tolerance requirements for positioning of the components. After PC board 18 is loaded into position, a conical-shaped tool 240 is depressed within the inside cavity of the terminal post to cause it to become flared, thus interlocking the terminal with the PC board and bringing the terminal close to the PC board soldering surfaces or pads.In addition to facilitating assembly, this technique also improves the mechanical engagement between PC board 18 and the electrical terminals of the various components. Such mechanical interengagement is particularly importance since controller 18 is intended to be used in a harsh vibrational environment. Pins 236 of electrical connector 20 are preferably deflected to mechanically engage PC board 18. With this arrangement, electrical connector 20 is prevented from being withdrawn from bore 52 due to interlocking with PC board 18, and cannot be further inserted into the bore due to the engagement of shoulder 226 with manifold 12.

PC board 18 is mechanically connected to manifold 12 by fasteners threaded into bores of posts 58 to improve vibration reliability and ruggedness for installation handling. Such fasteners could be conventional types or of the "break-away" or "torque-off" variety previously described to discourage tempering. Preferably, PC board 18 is enclosed by cover 19 which snaps onto the PC board, thus protecting the electrical connections.

Claims (4)

1. A solenoid assembly comprising: an energisation coil defining a longitudinal bore, a pole means defining a first surface disposed in said bore, a movable armature disposed in said bore and adapted to translate in said bore in response to energisation of said coil, said armature defining a second surface which faces said first surface of said pole means, said first and second surfaces defining a first working air gap across which magnetic fields are transferred thereby generating an attracting force between said pole means and said armature urging said armature to move in said bore, said armature further defining a conical shaped third surface, a flux collector plate defining a conical shaped fourth surface which faces said armature third surface, and said third and fourth surfaces defining a second working air gap across which magnetic fields are transferred thereby generating an attracting force between said flux collector plate and said armature, said attracting force having a component which acts in the direction of movement of said armature, thereby augmenting the attracting force provided across said first air gap.

2. A solenoid assembly according to claim 1, wherein said flux collector plate defines a central bore through which said armature moves.

3. A solenoid assatibly according to claim 1 wherein at least one Cf said surfaces defines local projections which contact the corresponding surface to thereby control tbe minimum distance of either of said air gaps.

4. A transmission controller assembly constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

4. A solenoid assembly according to claim 1 "herein said solenoid assembly is employed to actuate a fluid control valve assembly.

5. A variable force solenoid assembly, comprising: a coil assembly defining central bore, an armature disposed in aid central bore, a tirst flux collector plate defining a threaded bore, an adjuster Sleeve made of a non-magnetic material threaded into said flux collector plate threaded bore, laid adjuster sleeve having a central threaded bore and adapted to contact aid antature to establish the iiinimLZn air gap between said armature and said first collector plate, a pin member threaded into aid adjuster sleeve bore, and spring sears coupled to laid pin member and said armature such that threading aid pin member into aid adjuster Sleeve changes the compliant force acting on said armature.

6 . A variable force solenoid assembly according to claim 5 wherein said armature is comprised of a cylindrical member having a first generally closed end vith a central bore and a second opened end, and an insert disposed in said cylindrical manner second opened wend, said armature disposed in aid coil assembly central bore such that aid pin natber passes through said first end of said cylindrical manner.

7. A variable force solenoid assembly according to claim 5 further comprising r valve assembly which controllably reduces an inlet pressure to a control pressure, comprising: a spool valve having a central stem and tirst and second headed ends joining aid ten, a valve body defining a bore and a first dsber, said spool valve first headed end disposed in said bore and said second beaded end disposed in aid first chamber such that the surface of aid second beaded end adjacent said stem is exposed to said first Ser, said valve body further defining a second chamber exposed to the surface of aid second beaded and opposite said stem, first passage snans for communicating fluid at inlet pressure to aid first chamber, second passage means; for communicating aid valve body bore to fluid at control pressure and to said second chamber, third passage means for enabling fluid flowing between aid first headed end and said valve body bore to be vented to a su"::p, such that when fluid at inlet pressure acts upon said spool valve through aid first and second Xbers, thereby causing said second beaded end to be displaced toward said s valve bore therty providing a restriction to the flow of said fluid and reducing its pressure, said restriction to flow of fluid coupled with leakage of fluid past aid first headed end combining to provide said control pressure, said control pressure varying in response to loads imposed on aid spool valve w said spring means.

8. A solenoid assembly constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows

1. A solenoid assembly comprising: an energisation coil defining a longitudinal bore, a pole means defining a generally flat first surface disposed in said bore, a movable armature disposed in said bore and adapted to translate in said bore along an axis in response to energisation of said coil, said armature defining a generally flat second surface which confronts said first surface of said pole means, said first and second surfaces being generally perpendicular to said axis and defining a first working air gap across which magnetic fields are transferred thereby generating an attracting force between said pole means and said armature urging said armature to move in said bore along said axis, said armature further defining a conical shaped third surface, a flux collector plate defining a conical shaped fourth surface which confronts said armature third surface, said third and fourth surfaces defining a second working air gap across which magnetic fields are transferred thereby generating an attracting force between said flux collector plate and said armature, said attracting force having a component which acts along said axis, thereby augmenting the attracting force acting across said first air gap.

2. A solenoid assembly according to claim 1, wherein said flux collector plate defines a central bore through which said armature moves.

3. A solenoid assembly according'to claim 1, wherein at least one of said surfaces has local projections thereon for contacting the corresponding surface thereby to control the minimum distance of either of said air gaps.