Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K31/00—Actuating devices; Operating means; Releasing devices
  • F16K31/44—Mechanical actuating means
  • F16K31/52—Mechanical actuating means with crank, eccentric, or cam
  • F16K31/528—Mechanical actuating means with crank, eccentric, or cam with pin and slot
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/52—Systems for actuating EGR valves
  • F02M26/53—Systems for actuating EGR valves using electric actuators, e.g. solenoids
  • F02M26/54—Rotary actuators, e.g. step motors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/52—Systems for actuating EGR valves
  • F02M26/55—Systems for actuating EGR valves using vacuum actuators
  • F02M26/58—Constructional details of the actuator; Mounting thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/65—Constructional details of EGR valves
  • F02M26/66—Lift valves, e.g. poppet valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K31/00—Actuating devices; Operating means; Releasing devices
  • F16K31/02—Actuating devices; Operating means; Releasing devices electric; magnetic
  • F16K31/04—Actuating devices; Operating means; Releasing devices electric; magnetic using a motor
  • F16K31/047—Actuating devices; Operating means; Releasing devices electric; magnetic using a motor characterised by mechanical means between the motor and the valve, e.g. lost motion means reducing backlash, clutches, brakes or return means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K31/00—Actuating devices; Operating means; Releasing devices
  • F16K31/44—Mechanical actuating means
  • F16K31/52—Mechanical actuating means with crank, eccentric, or cam
  • F16K31/524—Mechanical actuating means with crank, eccentric, or cam with a cam
  • F16K31/52408—Mechanical actuating means with crank, eccentric, or cam with a cam comprising a lift valve

Definitions

• the invention relates to a valve, in particular a valve intended to be implemented in the automotive field.
• the invention more particularly relates to an exhaust gas recirculation valve, or EG valve, of the English "Exhaust Gas Recirculation”.
• the invention also relates to a method of manufacturing such a valve.
• valves comprising a valve opening control member, for example a toothed sector wheel, which rotates against a return spring acting in torsion.
• the return spring removes the control member in a specific position, once the actuation of the control member is completed.
• the return spring also keeps the control member in the determined position in the absence of actuation, despite the vibrations to which the valve can be subjected.
• Such a valve may in particular be of the valve type moving in translation or in a helical movement, with respect to a valve seat which selectively closes.
• a device is interposed functionally between the control member and the valve stem, which transforms the rotation of the control member in translation, respectively in helical movement, of the valve stem.
• EGR valve of this type is known from FR-A-2 914 975 or FR-A-2 947 027, in the name of the Applicant.
• EGR recirculation valves
• Figure 1 illustrates an EGR valve according to FR-A-2 947 027.
• the valve 100 comprises a valve 102 which allows the introduction and metering of the exhaust gas into the intake duct of a combustion engine of a motor vehicle.
• the valve 100 comprises an electric motor 104 meshing with a transmission wheel 106.
• the transmission wheel 106 meshes with a control member 108, here a toothed sector wheel.
• a camming cam 110 By means of a camming cam 110, the rotational movements of the toothed sector wheel 108 are converted into reciprocating movement of the valve 102 relative to a valve seat. More specifically, a hitch 112 is mounted in the cam 110, which is rotated by the toothed sector wheel 108.
• the hitch 112 comprises a bar 114 with a roller 116 free to rotate at each of its ends, each roller 116 being received in a respective track of the cam path of the cam 110.
• a valve stem 118 integral in translation with the The bar 114 and the valve 102 then makes it possible to raise the valve 102 of a valve seat to selectively open the valve 100.
• toothed sector wheel 108 is returned to the closed position of the valve 100 by a return spring 112, acting in torsion.
• the rollers are assembled on the bar, received in the cam from the outside of the cam. This way of proceeding is however complex.
• the hitch once assembled, is inserted into the cam, from an axial end of the cam, through two recesses in the side wall of the cam, of passage of the hitch, which open on the one hand at an axial end of the cam and, on the other hand, in the cam path.
• the insertion of the hitch is then carried out by maintaining it in a position where the axis between the two rollers is contained in a plane normal to the axis of the cam.
• this way of proceeding remains complex.
• the presence of recesses in the side wall of the cam greatly reduces its mechanical strength, which is detrimental to the life of the cam.
• the invention aims to provide a valve EG, and more generally, a valve, including a valve for a motor vehicle, does not have the aforementioned drawbacks.
• the invention aims to provide a valve whose mounting is facilitated.
• the invention proposes a valve, in particular a valve for a motor vehicle such as an exhaust gas recirculation valve, comprising:
• a hinge integral in rotation with the control member and comprising a bar and two rollers free to rotate at the ends of the bar, the rollers being adapted to be guided in a cam cam, and
• the hitch and the cam being shaped to allow the bias insertion of the hitch in the cam, from an axial opening of the cam, so as to engage one of the rollers only in the cam path, and the rotation the hitch to place the other of the rollers next to the cam path.
• the mounting of the hitch in the valve is achieved in a few simple and quick steps, once the hitch assembled.
• Such a valve is therefore easier to manufacture.
• the valve may have one or more of the following features, taken alone or in combination: -
• the side wall of the cam is devoid of passage recess of the coupling, opening on the one hand to an axial end of the cam and on the other hand, in the cam path;
• the cam path comprises two tracks, each track preferably extending over an angular sector of at least 90 °, more preferably at least 100 °;
• At least one track of the cam path comprises at one end, preferably at the end that is axially closest to the axial end of the cam by which the insert is inserted.
• the hitch a chamfer facing the outside of the cam;
• the upper ramp of the one or more tracks of the cam path has, at the end having a chamfer, a variation of substantially continuous slope
• An end of at least one track of the cam path preferably one end of the two tracks of the cam path, has an opening in the side wall of the cam, of diameter greater than the diameter of a roller;
• the cam comprises at least one, preferably at least two grooves in the radially inner surface of the cam, the grooves preferably having a narrowing at their outlet on an axial end of the cam;
• the groove or grooves are angularly between the tracks of the cam path;
• the hitch In the closed position of the valve, the hitch is not in abutment laterally in the cam path.
• the invention relates to a method of mounting a valve as described above in all its combinations, comprising the steps of:
• FIG. 1 shows in perspective, a partially cutaway view of an EGR valve
• FIGS. 4 and 5 represent, according to different perspectives, a cam of the motion transformation device of FIGS. 2 and 3;
• FIG. 6 shows schematically in perspective the insertion of a hitch assembled to a valve stem in the cam of Figures 4 and 5;
• FIG. 7 shows schematically in perspective, the cam of Figures 4 and 5, provided with a hitch and fixed in a cam housing provided for this purpose in a valve body.
• valve for example an EG valve for a motor vehicle, a portion of which is illustrated in FIGS. 2 and 3.
• This valve comprises a valve 12 which allows the introduction and dosing of a fluid, here the exhaust gas, in a pipe, here the intake.
• the valve is of the type comprising a control member 14 rotating (or rotating) against a return spring 16 acting in torsion.
• the valve first comprises a valve body forming a conduit for the exhaust gas to be recirculated.
• the valve body may also form a conduit for cooling water circulation of the valve.
• the body may have valve mounting holes to a power unit of a motor vehicle.
• Such fixing holes may in particular be made in flanges surrounding the outlets of the cooling water circulation duct, thus making it possible to integrate the cooling water circulation duct of the valve into the water circulation duct. engine cooling on which the valve is attached.
• Such fixing holes may also be made in flanges surrounding the outlets of an exhaust gas recirculation duct.
• the valve also includes a motor that can be mounted in a housing formed by the valve body.
• the engine meshes with a transmission wheel.
• the transmission wheel in turn engages the control member 14, here a toothed sector wheel.
• the motor is thus adapted to rotate the toothed sector wheel 14.
• reciprocating movement here is meant a movement comprising a translation along an axis, possibly combined with a rotation with respect to this same axis.
• the movement transformation device 18 comprises, inside a support member formed by the valve body, a cam-shaped cam 22 (or cylindrical cam), a hitch 24 cooperating with the path of the cam.
• cam 22 of the cylindrical cam 20 the hitch 24 comprising a bar 25 fixed to the end of a rod 26 integral with the valve 12.
• the rod 26 in the valve body it can be provided one or more bearings between the rod 26 and the valve body. It can be provided a clearance between the rod 26 and the bar 25 to allow a rotation of the rod relative to the bar, around the axis of the rod, the bar and the rod being integral in translation in the direction of the axis of the rod.
• the cam path 22 is here formed of two identical tracks, on either side of a tubular wall of the cylindrical cam 20.
• the hitch 24 comprises, in addition to the bar 25, rollers 28 arranged at the ends of the bar 2 and cooperating with the cam path so that, when the toothed sector wheel 14 is rotated, the latter in turn drives the bar 25 in rotation causing, due to the travel of the rollers 28 in the cam path 22, the translation, or at least the back and forth, of the valve 12.
• the valve 12, the rod 26 and the bar 25 are fixed relative to each other and form a set whose displacement in the direction of the axis A of displacement of the valve 12 responds to the rotation of the toothed sector wheel 14 around the same axis A.
• a bearing 30, here a ball bearing to allow the rotation of the toothed sector wheel 14 with respect to the cylindrical cam 20.
• the toothed sector wheel 14 is rotationally integral with a skirt 32 designed to cooperate with the bar 25.
• This skirt 32 comprises two symmetrical longitudinal walls and extending essentially parallel to the direction A of rotation of the wheel. toothed sector 14 and translation of the valve 12.
• the two longitudinal walls define between them a housing for the bar 25.
• the bar 25 is disposed in the housing so that the toothed sector wheel 14 is able to drive in rotation the bar 25 through the longitudinal walls of the skirt 32, and that the bar 25 is free to slide in the housing in the direction of translation of the valve 12.
• the rotation of the toothed sector wheel 14 causes the rotation of the bar 25 whose rollers 28 then roll on the cam path 22 of the cylindrical cam 20, fixed, which leads to a joint movement.
• the valve 12 in the direction of the axis A, the displacement of the valve 12 and the rotation of the toothed sector wheel 14, between a position of the valve 12 corresponding to a closing of the valve and at least one position of the valve corresponding to a valve opening, it being understood that at each position of the valve 12 corresponds a single angular position distinct from the toothed sector wheel 14.
• the toothed sector wheel 14 is connected to the support member by means of a return spring 16 acting in torsion.
• the opening of the valve 10 is controlled by the rotation of the toothed sector wheel 14, control member, itself caused by the rotation of the motor, actuating member, against a restoring force exerted on the toothed sector wheel 14 by the return spring 16.
• the return spring 16 is here a helical spring A axis corresponding to the axis of rotation of the toothed sector wheel 14.
• the return spring 16 is connected at one end to the support member and, at the other end, the toothed sector wheel 14, such that the rotation of the toothed sector wheel 14 controlling the opening of the valve causes a twisting of the return spring 16.
• the return spring 16 may be connected to the support member in that one of its ends, bent in the opposite direction from the rest of the helical winding of the return spring 16, is received in a hole in the support member or cooperates with a abutment formed for this purpose by the return spring 16.
• the return spring 16 is here received in a substantially cylindrical housing delimited by the support member, the cylindrical cam 22 and the toothed sector wheel 14.
• the return spring 16 exerts a return force reminding the toothed sector wheel 14 in its position corresponding to the closed position of the valve.
• This position of the toothed sector wheel 14 corresponding to the closing of the valve may correspond to a prestressed state of the return spring 16.
• the return spring 16 exerts a force on the toothed sector wheel 14 tending to rotate it.
• the rotation of the toothed sector wheel 14 beyond the position corresponding to the closure of the valve is prevented by the fact that the valve 12 is abutting against a valve seat.
• cam 20 cam 22 we will now describe more precisely the cam 20 cam 22.
• the axis of the cam is oriented so that the top corresponds to the end of the cam intended to be oriented towards the toothed sector wheel 14 and the bottom corresponds to opposite end of the cam.
• the inside diameter of the cam 20 is chosen slightly greater than the length of the bar 25 so that the rollers 28 are received in the cam path.
• the outer diameter of the cam is chosen substantially equal to the length of the coupling.
• the cam path 22 of the cam 20 here comprises two cam tracks 34, formed by helical grooves delimited by a high helical ramp 36, the closest to the toothed sector wheel 14, and a low helical ramp 38 , opposite to the high helical ramp 36.
• the two cam tracks 34 are identical, offset by 180 °, to be able to receive the rollers 28 of the hitch 24.
• the height of the tracks is slightly greater than the diameter of the rollers 28 of the coupling 24.
• the side wall of the cam 20 is devoid of recesses in the wall, passage of the coupling, opening on the one hand to an axial end of the cam and on the other hand, in the path of cam.
• the cam 20 thus has an increased mechanical strength.
• this allows for cam tracks 34 extending over a larger angular sector. This allows, for a given height of the tracks, measured along the axis of the cam 20, to obtain a more high accuracy of the valve.
• the tracks 34 of the cam path here comprise, at their lower end, a chamfer 40 oriented towards the outside of the cam 20.
• the opening in the side wall of the cam 20, at this level. end is wider at the radially outer surface of the wall than at the radially inner surface.
• the opening in the side wall can thus be at this low end, frustoconical, at least in parts.
• This chamfer makes it possible to engage a wheel of the hitch only in the cam track (the other wheel being for example always outside the cam), then to rotate the hitch to put the second roller next to the cam path.
• engaging a roller in the cam path is meant here inserting this roller in the cam path from the inside of the cam and projecting it out of the cam 20.
• the variation of slope at this chamfer 40 at the end of the track 34 of the cam path is substantially continuous, so as not to form a protruding stop which could block hitch during assembly.
• an opening is made in the side wall of the cam, of diameter greater than the height of the rollers 28.
• the hitch 24 does not abut laterally in the cam path 22.
• the stop be made at the valve against the valve seat.
• the cam 20 comprises two axial grooves 44, made in the radially inner surface of the side wall of the cam 20. These grooves 44 have a narrowing 46 at their outlet on the lower axial end of the cam . These grooves allow the attachment of the cam in a valve body by means of screws. Preferably, for reasons of resistance of the cam, the grooves 46 are, contrary to what is shown, located angularly between the tracks 34 of the cam path 22.
• the cam 20 forms at its upper axial end, the closest to the toothed sector wheel 14, a housing 48 for receiving a bearing to allow rotation of the toothed sector wheel with respect to the cam 20. .
• a hitch 24 and a cam 20 are provided. It should be noted here that, preferably, the hitch 24 is provided while the valve stem 26 is already secured to the hitch, the valve stem 26 being preferably provided with the valve 12.
• the hitch 24 is inserted diagonally into the cam 20, through an axial opening of the cam - here the low opening, opposite to the toothed sector wheel - for engaging a first roller 28 of the hitch 24 in a track of the cam path 22.
• the roller 28 can be engaged at the lower end of the track 34 of the cam path, the furthest away from the sector wheel toothed.
• the roller can here be engaged in this end while the coupling is biased because the opening in the side wall of the cam is of greater diameter. It will be noted here that, in the position represented by the coupling, the second roller 28 is outside the cam 20.
• the hitch 24 is pivoted, the first roller 28 is always engaged in the cam path 22, to place the second roller 28 of the hitch 24 opposite the cam path 22.
• This pivoting of the hitch 24 is here possible, in particular, because of the chamfer 40 around the opening 42.
• the presence of the grooves 44 can facilitate this pivoting, because they give more space to maneuver the hitch 24.
• the first and second rollers 24 of the hitch 24 can then be inserted in the cam path 22, that is to say that the two rollers 28 are each in contact with a helical ramp of a track 34 of the cam path 22. To do this, simply shift the hitch in a plane substantially normal to the axis of the cam 20.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanically-Actuated Valves (AREA)

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ID=50933379

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Family Cites Families (6)

• 2014
  • 2014-04-01 FR FR1452884A patent/FR3019248B1/fr active Active
• 2015
  • 2015-03-31 WO PCT/FR2015/050832 patent/WO2015150692A1/fr active Application Filing
  • 2015-03-31 EP EP15717049.9A patent/EP3132169A1/de not_active Withdrawn

Non-Patent Citations (1)

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