FR2562954A1 - FUEL INJECTION APPARATUS AND SYSTEM - Google Patents

Abstract

THE INVENTION RELATES TO A FUEL DOSING APPARATUS 10 COMPRISING A BUTTERFLY BODY 12 THROUGH A SUCTION DUCT 14 AND A BUTTERFLY 16 CONTROLLING THE FLOW IN THIS SUCTION DUCT, AN AIR-FUEL MIXING ELEMENT , IS LOCATED GENERALLY IN THE SUCTION PIPE DOWNSTREAM OF THE BUTTERFLY, AN AIR PASSAGE ESTABLISHES A COMMUNICATION BETWEEN AN AIR SOURCE AND THE AIR-FUEL MIXTURE EMISSION ELEMENT, THIS AIR PASSAGE CONTAINS A CHANGER 78 WHICH PRODUCES A SONIC FLOW THROUGH IT, AND A FUEL METER VALVE ASSEMBLY 104 HAVING A SPHERICAL SHUTTER DOSES THE LIQUID FUEL AT A PRESSURE SUPERIOR TO THE ATMOSPHERIC PRESSURE AND EMITS THE LIQUID FUEL DOSE IN THE AIRWAY OF THE STRANGER 78.

Description

1. The present invention is in the field of injection systems for

  fuel and more particularly on

  dosing fuel injection systems and apparatus

  age of the fuel supply to an associated combustion engine. Although the automotive industry has, over the years

  years, if only to seek benefits

  , continually striving to increase the fuel economy of automotive engines, the gains

  continuously achieved by this means have been deemed insufficient

  health by different levels of government. In addition, these

  levels of government have arbitrarily imposed rules

  items specifying the maximum permissible quantities of mono-

  carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides

  te (NOx) that engine exhaust can emit

in the air.

  Unfortunately, in general, the technology

  existing gie usable to try to achieve increases

  The fuel economy of the engines is contrary to the technology that can be used to try to meet the exhaust emission standards imposed by

the government.

  For example, the prior art, in an attempt to meet the standards for N 0x emissions, has

  used an exhaust gas recycling system by the-

  which at least part of the exhaust gas is reintroduced

  pick in the combustion chamber of the cylinders for there-

  lower the combustion temperature and therefore reduce

re the formation of NOx.

  The prior art has also proposed the use of

  tion of recycling means by the crankcase, the vapors which could otherwise escape into the atmosphere being introduced into the combustion chambers of the engine to

be re-burned.

  The prior art has also proposed the use of

  tion of fuel metering means which are effective for

  supply the engine combustion chambers with an air-

  fuel relatively too rich (in fuel) in order to

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2.

  reduce the formation of NOx in the combustion chamber. Read-

  use of such overly rich mixtures results in an increase

  significant CO and HC levels in the exhaust, which

  stops the supply of additional oxygen, by an associated air pump, to the exhaust for the completion of the oxidation

  tion of CO and HC before their emission into the atmosphere.

  The prior art has also previously proposed delayed ignition as another means of reducing NOx formation. It was also used from below

  compression ratio to lower the combustion temperature

  tion in the combustion chamber and thus reduce the formation

  NOx tion. The prior art has used in this respect what is generally called a double-bed catalyst: a first catalyst, chemical reducing agent, is located in the exhaust gas stream at a location relatively close to the engine, and a second catalyst, chemical oxidant, is

  located in this same current at a place further from the mo-

  tor, downstream from the first. The relatively large concentrations

  CO liftings resulting from too rich air-fuel mixture

  are used as NOx reducers in the first cat-

  lyser, while additional air supplied (by an associated pump) to the exhaust gas stream at one location

  located between the two catalysts serves as an oxidant in the two

  xth catalyst. These systems have been found to have

  towards disadvantages: for example, they are comparatively

  very expensive in that they require additional circuits

  air pump and an extra bed of cat-

  lyser. In addition, in these systems, there is a tendency to

  ammonia formation, which may or may not be re-

  transformed into NOx in the oxidizing catalyst bed.

  The prior art has also proposed the use of

  sation of injection means and metering of fuel for

  eliminate the carburetor usually used and, at a

  higher than atmospheric pressure, inject the

  fueled by individual injectors directly into the

  different cylinders of a piston type thermal engine

  tones. These fuel injection systems, in addition to

  are expensive, have not proven to be good in that the system

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  3. teme is called upon to produce a metered fuel flow in a very wide range of flow rates. Generally, prior art injection systems which are very accurate

  at one end of the required range of metered car flow rates

  burant are relatively inaccurate at the other end of this

  same beach. Likewise, the injection systems of the tech-

  previous pic designed to be exact in the middle of the

  required ages of metered fuel flows are usually

  relatively inaccurate at both ends of this same plate

  ge. The use of reaction means to modify the

  dosing characteristics of these injection systems

  burant of the prior art did not solve the problem

  inaccurate dosage, because the problem intertwines ordinary-

  factors such as the effective opening section of the injector, the relative movement required by the associated nipple or injector shutter, the inertia of the injector shutter and the opening pressure of the injector. And the smaller the metered fuel flow, the more influence

of these factors on him is great.

  It is now expected that said levels of government will

  will set exhaust emission limits

even more rigorous.

  The prior art, having regard to these requirements

  NOx, proposed the use of a cataly-

  three-way, single bed, in the gas stream

  as a means of observing these pre-

  exhaust emission views. Generally speaking, a ca-

  tridirectional talyseur is a single catalyst or a met

  a range of catalysts which catalyzes the oxidation of hydrocarbons

  bures and carbon monoxide and also the reduction of o-

  nitrogen xides. A difficulty encountered with this system

  tridirectional talyseur is that if the dosage is too rich (in fuel), the NOx are well reduced, but the oxidation of CO is incomplete, and if the fuel dosage is too lean, the CO is well oxidized, but the reduction in NOx is incomplete. Naturally, to make this three-way catalyst system effective, it is necessary to have very precise control of the fuel metering function of the means

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  4. supply and associated fuel dosage supplying the engine. As indicated above, the prior art has proposed the use of fuel injection means comprising an injector for each combustion chamber of the engine, with associated reaction means (controlled by

  selected indices of conditions and function parameters-

  engine) intended to change or modify so

  continues the dosing characteristics of the injection means

  fuel. However, as also indicated above, these fuel injection systems did not

turned out good.

  It has also been proposed in the past to use fuel metering means of the carburetor type with reaction means responding to the presence of constituents

  chosen in the exhaust gases. Such means of reacting

  tion were used to modify the action of a needle

  main dosing system of a main car dosing system

  fuel from a carburetor. However, testing and experience

  these have shown that such a prior art carburetor

  re and such associated reaction means could never provide the necessary level of accuracy in feeding

  dosed with fuel from an associated engine to ensure

  for example, exhaust emission standards

mentioned above.

  It has also been proposed in the past to use metering means of the fuel injection type comprising

  a valve controlled by an electromagnet and more particularly-

  a sealing means carried by the armature of the electro-

  magnet. Although this general type of metering means has been shown to be effective with regard to its metering function, the production cost of the solenoid-controlled valve

has generally been prohibitive.

  In addition, various devices of the prior art

  had problems with their ability to provide

  fuel dosed either at an appropriate flow rate or

  appropriately, to produce a smooth acceleration of the

  engine and / or vehicle when requested.

  Consequently, the invention presented and described

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  5. Mainly aims to solve these and other problems

  related and concomitant problems of the prior art

  re. According to the invention, a valve assembly for variably reducing a flow of fluid comprises a housing, an electric field winding carried by this housing, a pole piece situated generally inside this

  field winding, a shutter seat, a fluid passage

  in fact in this seat, the pole piece comprising a part

  extreme axial, a generally spherical shutter

  between this end and the shutter seat,

  a frame generally located inside the box

  field hoeing, and an elastic means which normally pushes the spherical shutter plastically for its application

  against the seat to stop the flow through the passa-

  fluid age, the spherical shutter having a surface

  flat against which the reinforcement is applied and, by the

  tion of the elastic means, push the spherical shutter to

its application against the seat.

  Various purposes, advantages and general aspects and par-

  particulars of the invention emerge from the detailed description-

  The next row illustrated by the accompanying drawings.

  In these drawings, on which certain details and / or elements can be omitted for clarity: fig. 1 shows, for the most part in section, an apparatus and a fuel injection system incorporating the teachings of the invention, FIG. 2 is a partial end view in the direction of the arrows 2-2 of FIG. 1, fig. 3 is an axial section along line 3-3 of FIG. 2, fig. 4 is an axial section of one of the elements shown in FIG. 3, fig. 5 is an end view in the direction of the arrows 5-5 of FIG. 4,

  fig. 6 is a side view of the elements shown

felt in figs. 1 and 3,

  fig. 7 is a view in the direction of fl1-

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  6. ches 7-7 of fig. 6, fig. 8 is a section along line 8-8 of FIG. 7,

  fig. 9 is a view in the direction of the arrows

  ches 9-9 of fig. 8, fig. 10 is an axial section of one of the elements shown in FIG. 3, fig. 11 is an end view in the direction of the arrows 11-11 of FIG. 10, fig. 12 is a side view of one of the elements shown in FIG. 3, fig. 13 is a section along line 13-13 of FIG. 12, fig. 14 is an end view in the direction of the arrows 14-14 of FIG. 12, tour of 900, fig. 15 is a section along line 15-15 of FIG. 14, fig. 16 is an end view in the direction of the arrows 16-16 of FIG. 15, fig. 17 is a section along line 17-17 of FIG. 15, fig. 18 is a section along line 18-18 of FIG. 15,

  fig. 19 is an axial view at the end of one of the

  elements shown in fig. 3, turned 90, fig. 20 is a section along line 20-20 of FIG. 19,

  fig. 21 is an axial end view in the di-

  rection of the arrows 21-21 of fig. 20,

  fig. 22 is a view of one of the elements represented

tees in fig. 3,

  fig. 23 is a view in the direction of the arrows

chs 23-23 of fig. 22,

  fig. 24 is a section through one of the elements shown

  felt in fig. 3, and fig. 25 is an end view in the direction

arrows 25-25 in fig. 24.

  Fig. 1 shows an apparatus 10 and a fuel injection system 8615 fi 7. constituted by a suction body 12 having a suction duct 14 in which is a throttle valve 16 which is carried by a rotary axis 18 to rotate with it and thereby variably reduce the air flow passing through the suction duct 14 and entering the engine 20 through the intake manifold 22 thereof. A suitable air filter can be provided surrounding the inlet of the suction duct 14 as shown partially at 24. The butterfly 16 can be suitably connected by a linkage and movement transmission means 26 to

  control of the gases operated by the operator who, as

  presented in general, can be the pedal or lever

  accelerator 28 as ordinarily provided in vehicles

automobiles.

  A fuel source such as a fuel

  vehicle fuel service 30 supplies an associated pump 32 which sends unmetered fuel, via a conduit 34, to a conduit 36 going to a chamber 38 which communicates with a

  passage or conduit 40 going to a pressure regulator 42.

  As shown in general, this pressure regulator

  sion 42 may include a cavity or part of the chamber type

  44 made in the body 12 and a bell-like cover 46.

  A deformable diaphragm 48 secured to the tail 50 of an ob-

  impeller 52 by opposite support plates 54 and 56 is enclosed and generally retained peripherally between cooperating parts of the body 12 and the cover 46 to delimit variable and distinct chambers 44 and 58, the

  chamber 58 communicating with a source of atmospheric pressure

  ambient air through a vent or passage 60. A seat or

  orifice element 62 cooperates with the shutter 52 to allow

  controllably put the fuel passage between the two and its entry into a passage 64 and a

  return 66 which, as shown, preferably brings back the ex-

  fuel at the source 30. A spring 68 placed in the chamber 58 acts on the diaphragm 48 and pushes elastically

  the shutter 52 against the seat 62.

  Generally, unmetered fuel can

  be brought to conduit 36 and to chamber 38 under a pressure

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  sion for example slightly greater than 0.70 x 105 Pascal.

  The conduit 40 transmits this pressure to the chamber 44, where it acts on the diaphragm 48 and the spring 68, which are

  chosen so as to open the shutter 52 to allow

  cap a little fuel and lower the pressure a little so as to maintain an unmetered fuel pressure

of 0.70 x 105 Pascal.

  Room 38 is sometimes connected

  with a fuel passage metered 70 through a fuel orifice

  rant dosed 72 which, in the preferred embodiment of the invention

  tion, is part of the fuel metering assembly 104, which, in FIG. 1, is not shown in section. Passage 70

  may contain a venturi 78 which may be a related element

  tee having a body 80 in which is made a passage 82 having

  a portion of the converging inlet or upstream wall 84 conducting

  sant at a groove from which extends downstream a part of the diffusing wall 86. A conduit 88, one end 90 of which communicates with a source of ambient atmosphere at its other end which communicates with the metered fuel passage 70 in a

  point or in the area upstream of the ventriction

  ri 78 and, generally, downstream of the fuel passage

rant dosed 72.

  A recess or annular cavity 92 made in the

  body 12 receives without play an annular element 94 which can a-

  see a converging upper or upstream annular part 96

  and a divergent lower or downstream annular part 98.

  The converging and divergent parties acting together

  the annular element 94 cooperate with the cavity 92 to form

  between them a ring or annular space 100 which commu-

  picnic with metered fuel passage 70 and end a-

  val or exit from the throttle 78. A series of angularly spaced emission ports 102 can be made in

  the annular element 94 on a circumference thereof.

  These orifices can be made in the downstream part of various

  98 so as to be in the general junction area of the upstream 96 and downstream 98 annular parts or below

this zone.

  Passage 72 is done in a shutter seat

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9.

  74 preferably carried by an oscillating type valve assembly

  teur 104. The metering assembly 104 is shown in FIG. 1

  mounted in a bore 108 made in the body 12, a joint to-

  risk 106 ensuring sealing. The left end (in FIG. 1) 110 of the metering assembly 104 is preferably housed without play in a bore 112 made in the body 12 and can be pressed axially against a shoulder 114. A seal

  O-ring 116 prevents leakage from bore 112 towards the passage

  sage 70. As shown generally in FIG. 1, there is preferably an appreciable free space around the main part of the metering assembly 104, the seals

  106 and 116 serving as sealing walls at the two ends

  your. An annular collar or retainer 118 which may include parts of the tab type (not shown) with screws passing through them and entering the body 12 can be used to hold the metering assembly 104 assembled with

the main body 12.

  As shown in fig. 2 and 4, the set do-

  seur 104 comprises a generally tubular housing 120 having a lower end wall (in FIG. 4)

  122, the outer surface of which forms a face 352. A prolongation

  generally tubular shape 124 preferably made

  body with the end wall 122 and contains a seat of-

  shutter 74 which is preferably mounted there by press. The housing 120 is provided with a circumferential groove 130

  intended to receive the annular seal 106.

  The inner cylindrical surface 136 of the housing receives without clearance a coil 138 which, as shown

  fig. 3, 12, 15 and 17, generally includes a core

  tubular track 140 with which are integral, at its ends,

  annular flanges extending radially 142 and 144.

  An electric winding or winding 146 located axially

  between the flanges 142 and 144 surrounds the core 140.

  Preferably, the coil 138 is provided with an upper part (in FIGS. 3, 12 and 15) 148 which has a cylindrical part 150 of larger diameter than the core with which an upper part 152 of the body forms part.

  flaccid type or disc directed radially outwards.

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  10. Two axially spaced extensions extending 154 and 156 are preferably molded in one piece with the disc or flange portion 152 and each contain, embedded in their mass, an electrical conductor of generally tubular shape 158 or 160 which has a stripped part 162 or 164 for its connection to an associated electrical conductor. As show

  perhaps best figs. 14 and 15, the electric conductors

  tubular trques 158 and 160 are each provided with a ral-

  lower lanyard 166 or 168 which itself has part of the

  like arm or leg 170 or 172 extending generally

laterally.

  As best shown in fig. 17, the flange 142 is preferably provided with notches or recesses 174 and 176 for the passage of the ends of the winding 146 for

  their connection to the legs or arms 170 and 172. After the

  reading of this connection, legs or arms 170 and 172

  are generally bent radially inward

  eur so as to be axially between the flanges 142 and 152

  and within their outer cylindrical surfaces.

* As shown in each of fig. 3, 14 and 15,

  the extensions 154 and 156 are preferably provided with

  rail type 178 and 180 molded in one piece a-

  with them and bend relatively elastically towards

1 interior.

  As best shown in Figs. 12 and 13, the flange 142 is provided with internal passages or conduits

  182 and 184 generally oriented radially which includes

  provide at their inner end radially with the

  passage or cylindrical vacuum 186 of the tubular core 140.

  In the preferred embodiment, the coil 138 is provided with a series of parts of the pad or leg type 188,, 192 and 194 as shown in detail in FIGS. 12, 15 and 16. Each of these parts of the tab type is preferably consisting of a portion extending radially

  196 which forms an integral part with an arched exterior segment 198. Com-

  shows me fig. 3, these parts of the tab type bear against the juxtaposed surface 200 of the wall 122 of the housing, which creates a flow space between this surface 200

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  11. and the axial end surface 202 of the flange 144 of the

  coil as well as between the angularly spaced arcuate segments-

  198 and the radiating parts 196 being one with them. As shown for example in Figs. 3 and 15, in the coil 138 is made a widening of the recess type 204 substantially axially aligned with the passage 186. The

  reel 138 is preferably made of glass filled nylon and soft

  and is heat stabilized.

  After the assembly of coil and contacts 138 has been produced as shown in FIGS. 14 to 18 and as described and that the field winding was carried out between the flanges 142 and 144 and connected to the terminals 170 and 172, the latter are folded towards the external surface of the hollow or groove, and the assembly is then put back in a mold and additional dielectric material (e.g. nylon

  loaded with glass) is added and molded onto the coil

  lesson to partially fill the hollow 150 to cover the

  terminals 170 and 172 then folded back and form an annular groove

  re 173 as shown in phantom in Figs. 12 and 15

and in solid lines in fig. 3.

  In fig. 19, 20 and 21 is shown a part

  this polar 206 which comprises a main cylindrical part

  only of the flaccid kind 208 which forms a body with an invisible part

  cylindrical lower 210 of smaller diameter aligned a-

  Sincerely with her. The main part 208 can be for-

  view above its upper surface 212 of an extension tu-

  bular 214 directed upwards forming an integral part of it and

  provided with an annular recess 216. In certain applications

  it may be opportune to maintain the device do-

  seur 104 assembled with the associated body 12 by a flange of the

  caliper type or the like, and in these cases the

  of can be received by the hollow 216. A passage 218 is made

  in the extensions 214 and 210 as well as in the main part

  cap 208 and a thread 220 is made in the upper part

  upper extension 214. The upper end of extension 214 may have a conical surface 222 and further be chamfered as shown in 224 and 226 to provide additional free space for fittings

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12.

  connect to terminals 162 and 164 (see also fig. 3).

  In the lower extension 210 are formed two conduits or passages 228 and 230 which radially pass through its wall and

  are preferably diametrically opposed.

  The main part 208 is also provided with diametrically opposite openings or passages 232 and 234 which, on the underside 236 of said part 208, are preferably chamfered as indicated at 238 and 240 respectively. In the preferred embodiment, the pole piece 206 is iron

  core of silicon or equivalent material.

  Figs. 22 and 23, as well as fig. 3, represents

  try a finger or guide element generally cy-

  indrique 242 which is preferably made of non-magnetic stainless steel of the AISI 300 series. This guide element 242 comprises a main cylindrical part 244 which has at its upper end in FIG. 22 an axial appendage 246

  of smaller diameter. A collar 248 having a surface of ap-

  then upper 250 and a lower bearing surface 252 is

  generally located at the lower end of the par-

  main tie 244 and slightly spaced from it by a sai-

  annular ring 254. Under the collar 248 is a part

cylindrical 256.

  Figs. 24 and 25, as well as fig. 3, represents

  try a generally annular guide shoe 258 which is preferably made of iron-silicon. More specifically, in the preferred embodiment, the outer cylindrical surface 260, the inner cylindrical surfaces 262, 264 and the outer cylindrical surface 266, of smaller diameter, are substantially coaxial while the generally planar upper surface 268 and the lower surface generally planar 270 are substantially perpendicular to the common axis of these cylindrical surfaces. The difference in diameter of the inner cylindrical surfaces 262 and 264

  creates an annular bearing surface 272.

  As shown in fig. 4 and 5, in the prolet-

  lower gage 124 of the housing 120, which is preferably made of steel, is formed a cylindrical passage 274 substantially

  coaxial with the cylindrical chamber 136. At least one opening

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  13. wall or passage 276 is provided in the wall of the extension

  124 to ensure communication through it. Preferably

  renee, near the lower end of the extension 124 is formed in the outer surface thereof, an annular groove 278 intended to receive the O-ring 116. In addition, preferably a series of openings or passages 280, 282 and 284 are made in the wall 122 to ensure communications through it and with the chamber 136. The upper cylindrical part 286 of the housing 120 is also provided with at least one passage or conduit 288 passing through its wall and preferably comprising a Chambering 290. The par-

  upper tie of the external part 286 of the housing 120 is provided with an external collar 292 (which can also be used

  partially delimiting the annular groove 130) and a pro-

  long cylindrical tubular directed upwards 294 which

  has an inner cylindrical surface 296 of appreciable diameter

  considerably greater than that of chamber 136. The difference in diameter between the internal cylindrical surfaces 136 and 296 allows the creation of an annular bearing surface of the shoulder type 298. The collar 292 can be used, in

  combination with an appropriate stop means such as for example

  ple the one shown at 118 in FIG. 1, to maintain

  the metering device 104 assembled with the mixing device

associated request.

  Figs. 10 and ll represent larger-

  as a filter 300 which, as we will see, serves as a vent.

  This filter 300 preferably comprises a tubular body 302 having an outer cylindrical surface 304 and an inner cylindrical surface 306. Two ramp-type tabs 308 and 310, preferably diametrically opposite, are made on the body 302 on the outer surface thereof. In the preferred embodiment, the body 302 and the tabs 308, 310 are molded from nylon loaded with 33% glass or equivalent material. It is preferable that during molding, a filter element or screen 312 is molded in place across the entire passage 314 delimited by the cylindrical surface.

  interior 306. In the preferred embodiment, the wire element

  trant or sieve 312 is made of nylon fabric having a percentage

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14.

30% vacuum age.

  In fig. 6 to 9 is shown an input filter

  trée 316 which generally includes a main part

  annular track 318 with which an annular wall forms part

  laire inclined radially inwards 320 from which leave a series of spacers 322, 324, 326 and 328 inclined towards the axis 330 of the filter 316. All these spacers end in a lower annular part (in FIG. 6) 332. The

  spaces between the spacers are provided with wire parts

  trantes 334, 336, 338 and 340. In the preferred embodiment, the filter 316 is molded from nylon loaded with 33% glass and

  the filter parts 334, 336, 338 and 340, which are pre-

  nylon fabric case having a void percentage of%, can be molded in place during molding. In addition,

  in the preferred embodiment, the inner cylindrical surface

  eure 342 of main part 318 has a diameter which pro-

  has a tight fit with the outer cylindrical surface

  eure 344 of the upper part 286 of the housing 120, the over-

  inner cylindrical face 346 of the annular part 332 has a diameter which produces a tight fit with the outer cylindrical surface 348 of the lower extension 124 of the housing 120 and, preferably, the inner surface 350 of the inclined wall part 320 conforms to the surface lower

  inclined 352 of the wall 122 of the housing 120.

  As shown in fig. 2 and 3, in reality

  preferred position, the shutter seat 74 is generally

  cylindrical rale and is press fitted in the passage 274 of the extension 124 of the housing and preferably welded in place with the laser. The seat 74 includes an orifice or passage

  calibrated 72 which, at its upper end, flares out

  curved in a smooth continuous curve as shown

  in 356. In the preferred embodiment, seat 74 is in a-

  magnetic stainless steel AISI 416. It should be mentioned-

  that non-magnetic stainless steel behaves

equivalent.

  In fig. 3 also shows an adjustable spring seat 358 which comprises a main part 360

  of generally cylindrical shape which has a pi-

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15.

  lot extending axially 362 and having an annular groove

  re 364 intended to receive an O-ring seal

  366. The upper part of the spring seat 358 is threaded

  externally in 368 in order to be engaged with the

  internally threaded tie 220 of pole piece 206. Suitable tool engagement surfaces, for example a

  cruciform footprint 370, are provided to allow the re-

  axial sliding by screwing the spring seat 358 by means of a tool. The main part 360 is naturally slidably mounted in the interior passage 218 of the pole piece 206. A spring 372 is placed in the passage 218 of the

  pole piece 206 and, at its ends, leans against the

  adjustment element 358 and guide element 242 and is pi-

  lot by pilot parts 362 and 246.

  As mentioned earlier, the guide element

  242 is made of non-magnetic material while the annular element

  area 258 is made of magnetic material. In addition, the diameter of the lower part 256 (of the guide element 242) and the

  diameter of the inner cylindrical surface 264 (from the 6

  258) are such that there is an adjustment between them

  clamped or pressed, while the inner cylindrical surface 262 freely receives the collar 248 of the

  guide 242. When the guide element 242 and the anu-

  258 were assembled with the press so as to have the shape shown generally in FIG. 3 they

work as a whole.

  In fig. 3 also shows a spherical shutter 376 which has a planar upper surface 378. In the preferred embodiment, this planar surface 378 does not pass

  not through the center of the shutter 376 and may be at a distance

  tance of this center on the order of a third of the radius of the obtur-

  tor 376. In the preferred embodiment, the spherical shutter

  that 376 is made of soft magnetic stainless steel and has a diameter

  meter as it fits tightly but freely in the passage 274 of the extension 124 of the housing. For example, the clearance between the shutter 376 and the passage 274 can be

in the range of 0.01 to 0.02 mm.

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  16. In the preferred embodiment, the various elements are assembled in the following manner. The filter or vent 300 is introduced into the openings 288 and 290 of the housing 120 so that the parts 308 and 310 are supported in the recess 290. An O-ring 380 is placed around the part 210 of the pole piece 206. L coil 138, with the field winding 146 already assembled with it, is assembled with the pole piece 206 (with the O-ring 380 placed on it) by introduction of the extensions 154 and 156 of the coil assembly through the openings or passages 232 and

  234 respectively, until the pawls of the genus ram-

  pe 178 and 180 pass beyond the surface 212 of the pole piece and thus prevent accidental disassembly of these

  elements. The O-ring 380 is then tightened between the sur-

  outer face 210 of the pole piece 206 and the surface

coil 204 of coil 138.

  An O-ring 382 can then be placed in the annular groove 173 of the coil 138, and the subassembly formed by the coil 138 (with the field winding 146) and the pole piece 206 is introduced into the housing 120, with the flange or main part 208 of the pole piece is

  housed inside the interior surface 296 of the housing

  ment 120 and abutting against the shoulder 298 of the housing 120 while the pole piece 206 pushes the parts of the leg type 188, 190, 192 and 194 of the coil 138 in contact with

  the interior surface 200 of the housing 120. The upper end

  the housing can then be crimped, stapled or wound (as shown generally in 384) against the upper surface 212 of the flange 208 of the pole piece for holding the housing 120 together, the

  coil 138, coil 146 and pole piece 206.

  The hoof-like element 258 is applied

  press on the outside surface of part 256

  of the guide element 242 so as to be supported axially-

  ment against the surface 252 of the collar 248. The elements 242 and 258 thus assembled are then mounted by the passage 274 so that the part 244 of the guide element 242 is housed sliding in the passage 218 of the pole piece

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  17. 206. The ball shutter 376 is then mounted by

  the passage 274 so that its flat surface 378 is applied

  quée against the surface 270 of the element of the shoe type 258.

  The shutter seat 74 is then mounted to the press in the passage 274 so that when the shutter 376 is pressed on the surface 356 and the shoe-like element

  258 pressed against the flat surface 378, there is an inter-

  given valley, for example 0.13 mm, between the upper surface

  lower 250 of the collar 248 of the guide element 242 and the

  end surface 219 of the pole piece 206.

  A probe type gauge is engaged by the open upper part of the passage 218 of the pole piece and brought into contact with the guide element 242. The electrodes 162 and 164 are electrically connected to the pulse generator.

  associated electric, which makes it move in an oscil-

  latoire, axially relative to the axis of the passage 218 of the pole piece 206, the shoe 258 and the guide element

  242 as well as the spherical shutter 376. The amplitude of the

  upward (in fig. 3) is determined by the bu-

  ty of the surface 250 of the collar 248 of the guide element against the end surface 219 of the pole piece, while the amplitude of downward movement (in FIG. 3) is determined by the coming into contact of the spherical surface

  shutter 376 with the seat surface. While 1'-

  guide member 242, shoe-like member 258 and ball 376 continue to oscillate, the seat

  74 is pushed into the passage until the sensor detects

  te that their maximum stroke is for example 0.076 mm, which obviously means that when these elements are in their respective positions shown in FIG. 3, there is an interval of 0.076 mm between the abutment surface 250 of the collar 248 of the guide element and the end surface 219 of the pole piece 206. The sinking of the seat 74 is then stopped, the cyclic supply of the winding 146 is

  stopped and the probe is removed from passage 218. Preferably

  ce, the seat 74 is then laser welded to the housing 120.

  Then, the spring 372 is introduced into the former

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  18. open upper end of the passage 218 and engaged with the guide element 242, and the adjusting screw 358,

  fitted with an O-ring 366, is introduced in the pass-

  sage 218 and screwed into the threaded part 220 of the pole piece 206. The outer O-ring 106 is then placed in the groove 130 of the housing 120, then the filter 316 is

  mounted to the press on the housing 120 at fixed to it from another

  be appropriately so as to have the position represented

  generally shown in fig. 3. Finally, the O-ring

  that 116 is placed in the throat 278.

  The assembly 104 is then placed in a flow measurement device by means of which all the fluid going to

  the assembly 104 and the crossing passes through the wire parts

  trantes 334, 336, 338 and 340 of the inlet filter 316.

  The electrodes or terminals 162 and 164 are connected to an electric pulse generator which can be adjusted

  to produce a specific pulse width and / or cycle

  born. Fuel or a fluid simulating it is introduced through the orifice or conduit 276 and, when the shutter 376 opens and closes while oscillating relative to the seat 74, exits through the metered fuel emission passage. Pressure drop

  fluid through shutter 376 and seat 74 is main-

  substantially constant hold. Consequently, with the two variables, namely the width and / or the pulse cycle and the pressure drop, kept substantially constant, it suffices, in order to obtain the corresponding desired fluid flow, to adjust the tension of the spring 372. In general, the greater the preload of the spring 372, the smaller the flow rate of the metered fluid. When the spring preload 372 has been adjusted by means of element 358 so as to give the desired flow rate of metered fluid, the screw OR adjustment element

  358 is blocked by an appropriate means, for example by agra-

  fage. The assembly 104 thus calibrated is then removed from the flow meter and is ready to be used in an associated fuel metering system such as that shown generally in FIG. 1. The terminals

  162 and 164 can be connected respectively by connectors

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  19. ductors 390 and 392 to a control device 394. As can already be seen, the metering device 104 is of the type

  cyclically operated, winding or winding 146 é-

  both fed intermittently and causing the shutter 376 to move away from the seat 74 when it is supplied. Consequently, the effective flow section of the orifice or passage 72 can be determined in a variable manner and controllable by frequency and / or duration control

winding supply 146.

  The control device 394 can comprise, for example, control means of the electronic logic type and appropriate output means enabling it to receive

  one or more input signals of the parameter and pro-

  draw outputs from them. For example, a transducer

  Their temperature 396 can send to the control device

  394 by a channel 398 a signal indicative of the engine temperature; a sensor 400 can detect the oxygen content

  engine exhaust gases (in the exhaust piping

  pement 402) and send a signal indicative thereof to the control device 394 via a channel 404; a speed transducer 406 can send to the control device 394 by a channel 408 a signal indicative of the speed of the motor,

  while the value of the engine load, indicated by e-

  xample by the position of the butterfly 16, can be transmitted in the form of a signal to the control device 394 by a

  track 410. A source of electrical voltage 412 and an inter-

  associated breaker 414 can be connected to the

  control 394 by conductors 416 and 418.

  The operation is as follows. In a general way

  in the preferred embodiment, fuel under pressure

  sion is sent by the pump 32 to the conduit 36 and to the cham-

  bre 38 (its pressure being regulated by regulator 42), this

  fuel is metered by the effective metering section of 1'-

  orifice 72 and the metered fuel is emitted in the duct 70,

  passes through the constriction 78, enters the ring 100 and fi-

  nally goes through the emission ports 102 and goes to the

  tor 20. In the embodiment shown, the flow of fuel

  dant dosage will depend on the percentage of time, for a time

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  20. of arbitrary cycle or elapsed time, where the shutter 376

  will be relatively close to seat 74 or applied against it

  ci, compared to the percentage of time the shutter 376 will be

  relatively far from headquarters 74.

  These percentages depend on the output of the control device 394 going to the winding 146, which depends

  in turn various parameter signals received by the device

  order positive 394. For example, if the content sensor

  in oxygen 400 detects the need for enrichment in

  Burant of the working fluid sent to the engine and sends a signal reflecting this need to the control device 394, the latter, in turn, will control that the metering shutter 376 be opened for a greater percentage of time in order to produce the increased flow required metered fuel. Consequently, given the engine operating parameters and / or indices and / or ambient conditions chosen,

  the control device 394 will produce according to the

  corresponding channels suitable supply of the winding 146 (producing a corresponding movement of the shutter

  376) and thereby sending the metered flow rate then necessary

fuel.

  The prior art used pressures

  relatively high both upstream and downstream of the provision

  fuel metering device to try to get a pulp

  sufficient checking of fuel in the suction pipe

  tion. It was not successful.

  With the system of fig. 1 who makes the invention

  tion, excellent spray characteristics are obtained.

  fuel even when the upstream non-metered fuel pressure is around 0.7 x 105 Pascal (the prior art often uses non-metered fuel pressures

  upstream dosage of the order of 2.8 x 105 Pascals).

  In other words, in the environment of the

  lisation or of the assembly represented, the duct 88 supplies at least the major part of the air necessary for the maintenance of the idling of the engine when the throttle 16 is

* closed. As we can see, a circuit is formed by the

  inlet 90 of conduit 88, conduit 88, passage 70, passage

8615 FR

21.

  sage 82, the ring 100, the orifices 102 and the passage of as-

  piration 13 of the engine intake manifold; this circuit provides the engine 20 with all the air necessary for its operation at

  slow motion. Choke 78 is of such dimension that the flow

  Lement in passage 82 is sonic during idling of the engine. The fuel metered by the shutter 376 and injected into the passage 70 mixes with the air when the two enter the inlet 84 of the venturi 78 and accelerate

  up to a sonic speed. The fuel contained in the met

  the air-fuel oil is sprayed when it accelerates

  tion to sonic speed and then expansion

  in part 86 of venturi 78. Next, the air-car emulsion

  sprayed burant enters the ring 100, is emitted from it

  generally on the periphery of the suction duct 14 through the emission orifices 102 of the diffuser 94 and enters the

  passage 13 of the motor 20. In the embodiment shown, 1'-

  throttle 78 produces a sonic flow through it not only during idling of the engine, but also in other running conditions thereof and preferably in at least most of its operating range,

  When the engine needs to deliver more power

  this, the butterfly 16 is opened to the appropriate degree and the diff-

  the various parameters detection means send to the

  input signal 39.1 of the input signals which cause the fuel metering device 104 to produce the desired increase in the flow rate of metered fuel emitted in the passage 70 and, as described above, finally sent to the engine 20. It is naturally possible to provide a means

  temperature controlled to open the papill-

  lon 16 while idling the cold engine in order to-

  help maintain this walk and avoid a hard walk.

  On -a fi. 3, on which certain details may be

  wind, for clarity, be turned around their axis

  with respect to <tr normal position, each time the bo-

  hoeing 146 is alilnté, the path of the resulting flow is

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  22. generally constituted by tubular extension 210

  pole piece 206, the main part of the flas- genus

  as 208 of the pole piece 206, the upper part 286 of the housing 120, the wall 122 of the housing 120, the shutter 376 and the guide shoe 258, with return to the tubular extension 210 of the pole piece 206. note in this regard that the shutter 376 not only fulfills the shutter function but also plays the role of reinforcement in

  the whole system. In addition, in the preferred embodiment

  The element of the hoof type 258 also serves as a framework and,

  in the realization presented, can be considered as-

  both an annular frame. In any case, the shutter and

  reinforcement 376 "floats" in the bore or passage 274 to

  align itself on the surface 356 of the seat in its po-

  normally closed. That is, when the bobi-

  swim 146 stops being supplied, spring 372 pushes the element

  guide 242, the annular armature 258 and the shutter and armature 376 downwards (in FIG. 3), which produces

  the application, with closure, of the spherical part of 1'-

  shutter and frame 376 against the surface 356 of the seat 74.

  If the part 206 is aligned a little eccentric with respect to the axis of the housing 120 or the axis of the surface 356

  of the seat or that the flow path is weakened in a re-

  any region, which tends to cause poor alignment

  shutter ment and frame 376 with surface 356 when

  from the initial closing contact, the flat surfaces cooperate

  rantes 270 (of the annular armature 258) and 378 (of the shutter-

  ball bearing and frame 376) allow these surfaces to

  slide relative to each other, allowing the shutter to

  rator and frame 376 to find its position of application

  against the seat surface 356.

  When the winding 146 is supplied and therefore the shutter and armature 376, the annular armature 258

  and the guide element 242 mount against the action of the res-

  fate 372, their maximum stroke is determined by the stop of the upper surface 250 of the collar 248 of the element

  guide against the end surface 219 of the pole piece

  re 206. As can be seen in fig. 3, when this bu-

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  23. when there is a gap between the surface

  upper annular 268 of the shoe and frame 258 and the over-

  end face 219 of the pole piece 206. In the reali-

  sation preferred, this interval can be of the order of 0.15 mm. This permanent air gap naturally means that the armatures, more particularly the annular armature 258, and the pole piece 206 do not come into contact. This allows for lower levels of force when the winding 146 is energized

  and a reduced force decline time when it ceases to be

be powered.

  As already indicated, in the embodiment

  preferred, there is an appreciable interval between the surface

  this external cylindrical extension 210 of the part po-

  the inner cylindrical surface 186 of the coil 138. There is an identical or similar interval between

  the annular reinforcement 258 and the internal cylindrical surface

  re 186 of coil 138. In addition, as also already indicated

  qué, in the preferred embodiment, there is a significant gap between the outer periphery of the flanges 142 and 144 of the coil and the inner cylindrical surface 136 of the housing 120. The spaces between the elements of the leg type

  188, 190, 192 and 194 of the coil 138 allow a flow-

  lying between these while these leg-like elements or

  shoe 188, 190, 192 and 194 maintain the end surface

  tee 202 spaced from the facing surface 200 of the housing 120 and

  thus allow a flow between them. In the rea-

  preferred reading, the fuel, from the chamber 38 (fig. 1), passes not only through the inlet or inlets 276, but also through the passages 280, 282 and 284 to fill all the appreciable intervals mentioned and to wrap the winding

  146 and thereby prevent it from getting too hot.

  The passages 228 and 230 which create a communication-

  tion between the interior passage 218 of the pole piece 206

  and the interval between the extension 210 and the cylindrical surface

  that the inner 186 of the coil 138 prevent the trapping of fuel in the passage 218 of the pole piece 206, generally between the guide element 242 and the adjusting element 358, and the axial hydraulic blocking of the element

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24.

guide 242.

  The passages 182 and 184 of the flange 142 of the bo-

  bine communicate with the interval between the extension

  ge 210 and the inner cylindrical surface 186 of the coil 138. It can therefore be seen that in the preferred embodiment, the various intervals and various passages and connecting spaces

  allow fuel to flow through them.

  In addition, as shown generally

  in fig. 1, in the preferred arrangement, the chamber 108

  cevant the metering assembly 104 is large enough to allow the flow of fuel between it and the assembly 104, fuel leakage to the outside being prevented

  by sealing means 106 and leaks beyond the

  seems metered 104 and towards the engine prevented by the sealing means 116. In this arrangement, the authorized fuel

  to circulate in the metering unit 104 is communicated

  tion with the fuel contained in the chamber 108 surrounding the metering assembly 104 by the filter or vent 300. If fuel vapor is formed in the metering assembly 104, the fuel circulating in it will expel it through the vent

300 in room 108.

  In addition, it should be noted that the valve assembly 104 is not necessarily intended to be used in combination with a complete suction system like the one shown

  in fig. 1. The valve assembly 104 can be used as a

  partnership with any other motor suction system

  air-fuel, for example a system in which the fuel

  rant is dosed directly to each combustion chamber of the

  engine (this is done for example by fuel injection

  rant in the air flow at or near the intake valves) or by metering fuel in or near

  a main throttle body used to control the feed

  ment in working fluid of all the combustion chambers

tion of the engine.

  Although it has been presented and described only a preferred embodiment and selected modifications of

  the invention, it goes without saying that other embodiments and modi-

  fications of the invention are possible in the context of

appended claims.

8615 FR

25.

Claims (17)

  1. Valve assembly (104) for variably reducing a flow of fluid, comprising a housing (120), an electric field winding (146) carried by this housing, a pole piece (206) located generally at the inside this field winding (146), a shutter seat (74), a fluid passage (72) made in this seat (74), the pole piece (206) comprising an extreme axial part   (219), a spherical shutter (376) generally located   the between this end portion and the shutter seat (74), a frame (258) generally located inside the field winding (146), and an elastic means (372) which normally resiliently biases the shutter spherical (376) in engagement against the seat (74) to stop the flow through the fluid passage (72), the shutter   spherical (376) having a flat surface (378) against the   which the armature (258) is applied and, by the action of the elastic means (372), urges the spherical shutter (376)   in engagement against the seat (74).   2. Valve assembly according to claim 1, in which the spherical shutter (376) serves as an additional reinforcement. 3. Valve assembly according to claim 1 and further comprising a coil (138) located in the housing (120), this coil (138) comprising a tubular core (140) generally located in the middle, the field winding ( 146) being carried by this coil (138), and my pole piece (206) being at least partially housed in the tubular core (140).   4. Valve assembly according to claim 3, wherein the spherical shutter (376) serves as an additional frame. 5. Valve assembly according to claim 1 and further comprising a frame guide element (242) which is movable in an oscillatory manner relative to the workpiece   polar (206) at one end and relative to the shutter seat erator (74) at the other end.   6. Valve assembly according to claim 5, 8615 FR   26. in which the armature (258) is carried by the element of guide (242).   7. Valve assembly according to claim 5, wherein the armature (258) is fixedly carried by the guide element (242) to move with it. 8. Valve assembly according to claim 1 and further comprising a frame guide element (242) which can approach and move away from the shutter seat (74)   and whose movement away from this seat (74) is limited   tee by associated stop means (250, 219).   9. Valve assembly according to claim 8, in which the armature (258) is fixedly carried by the guide element (242) and is spaced from the pole piece (206) when the guide element (242 ), moving away from the shutter seat (74), comes into contact with the means of stop (250, 219).   10. Valve assembly according to claim 9,   in which the axial end portion (219) of the pole piece   re (206) includes a stop means.   11. Valve assembly according to claim 10, in which the guide element (242) is slidably mounted.   in a part of the pole piece (206).   12. Valve assembly according to claim 11 and further comprising a steam exhaust means (300)   which includes a passage (314) which passes through a wall of the housing ment (120).   13. The valve assembly of claim 12, wherein the exhaust means (300) comprises a filter   (312) generally located across the passage (314).   14. Valve assembly according to claim 1, wherein the pole piece (206) comprises a passage (218) extending generally towards the shutter seat   (74), and further comprising a reinforcement guide element   re (242) which can come and go in this passage (218) made in the pole piece (206) to approach and move away   the shutter seat (74) and the movement of which removes   ment of this seat (74) is limited by stop means as-   companies (250, 219), the armature (258) being worn so 8615 FR 2S62954   27. fixed by the guide element (242) and being spaced from the pole piece (206) when the guide element (242),   moving away from the shutter seat (74), comes into contact a-   with the stop means (250, 219).   15. Valve assembly according to claim 14, wherein the guide element (242) is made of non-magnetic material. 16. Valve assembly according to claim 14 and further comprising conduits (228, 230) made in the pole piece (206) to establish communication between the passage (218) extending generally towards the seat   shutter (74) and the rest of the interior space of the housing ment (120).   17. The valve assembly of claim 1, wherein the planar surface (378) is located on one side of the center of the spherical obturator (376) so that the remainder of the spherical surface of the obturator (376) be bigger than a hemisphere. 8615 FR