Patent Application
20150240755
The invention concerns a fluid flow valve, in particular for controlling a gas flow. It is used for example in the automotive sector. More particularly, the invention relates to a flow control valve for recirculated exhaust gas (EGR).
In general, an exhaust gas recirculation system of an internal combustion engine allows a reduction in the quantity of nitrous oxides present in the exhaust gases. Such systems comprise a valve allowing control of the gas flow which is taken from the engine exhaust in order to be introduced into the intake.
In this context, valves are known which comprise a moveable shutter allowing control of the recirculated exhaust gas flow, and a body comprising a protruding cylindrical part receiving said shutter. Said body is configured to be arranged on a support such that said protruding part is situated in a housing of said support which is shaped correspondingly to said protruding part.
Conventionally, the body is mounted on the support by screws oriented parallel to the longitudinal axis of said protruding part, said screws cooperating with passage openings arranged in the valve body, the axis of said openings being distributed angularly around said protruding part. The valve is fixed to its support by exerting a force in an axial direction. A simple flat seal, extending in a plane perpendicular to the axis of the housing, then suffices to ensure the desired tightness between said body and said support.
In view of this, because of the small space sometimes available below the hood, it is not always possible to position the passage openings on the valve so as to allow fixing of the valve in such an orientation. The valve would then have too great a radial dimension.
The invention proposes to remedy said drawbacks and to this end concerns a fluid flow valve comprising a mobile shutter and a body, comprising a protruding part receiving said shutter, said body being configured to be mounted on a support such that said protruding part is introduced into a housing of said support.
According to the invention, said body is also configured to allow fixing of said valve on said support in a direction transverse to a longitudinal extension direction of said protruding part. In this way a valve of reduced radial size is achieved. In fact relative to a valve with axial fixing, the fixing screws of which must necessarily lie radially outside the dimensions of the protruding part receiving the shutter, the choice of a fixing direction transverse to said longitudinal extension direction allows the valve to be fixed to its support in a limited radial space.
The valve may have a radial tightness between the protruding part and the support. “Radial” here is understood in particular as in opposition to “longitudinal”.
At the same time, the use of a radial tightness, i.e. a tightness obtained by radial compression of a seal applied at said protruding part, provides a simple and effective solution for the tightness between the valve and its support.
According to various embodiments of the invention which may be combined or applied separately:
According to advantageous embodiments, the material of the seal is selected from an elastomer of FPM (fluorocarbonated), PTFE (polytetrafluoroethylene), more commonly known under its commercial name Teflon®, and peroxided FPM.
The invention furthermore concerns an assembly of a valve as described above and an engine cylinder head forming said support.
Further characteristics and advantages of the invention will appear from reading the description below which relates to detailed exemplary embodiments, with reference to the attached drawings on which:
As illustrated on
Said valve 1 comprises a moveable shutter 2 shown on
Said support 8 comprises for example a surface 12 for supporting said valve and a surface 14, here perpendicular, for fixing the valve. Said housing 10 is provided opening at the level of said support surface 12. Said support could also comprise a threaded opening (not visible), serving for fixing the valve on said support 8. Said threaded opening is here situated on said fixing face 14.
Said support 8 allows the circulation of said fluid. For this it comprises for example an inlet channel 16 and an outlet channel 18. Said inlet channel 16 is oriented in particular radially relative to a longitudinal extension direction of said housing 10. Said outlet channel 18 is for example situated in the axial extension of said housing 10.
Said support 8 is here illustrated in a particularly diagrammatic fashion. It may amongst others be a cylinder head of an internal combustion engine serving to propel the vehicle fitted with said valve.
Said body 4 is for example a casting, in particular of aluminum or aluminum alloy.
It comprises a base 20 from which said protruding part 6 holding the shutter 2 originates. Another protruding part 22, serving to house a motor (not visible) for driving said shutter 2, may also originate from said base 20.
Said base 20 forms a housing or closed chamber which contains kinematic transmission elements (not visible) transmitting the movement from a motor output shaft to the shutter 2. The kinematic transmission elements comprise for example a toothed wheel gear mechanism assembled in the known fashion. In this way the degree of opening of the shutter is controlled. Said housing is closed for example by a cover 21 of said valve, in particular made of plastic material.
Said base 20 may also form a shoulder 24 extending radially beyond the protruding part or parts 6, 22. Said shoulder 24 serves in particular for fixing said cover 21.
Said protruding part 6 receiving said shutter 2 extends in a longitudinal extension direction D intended to correspond with the longitudinal extension direction of the housing 10 of the support 8.
Said protruding part 6 receiving said shutter 2 comprises for example a wall 26 defining an inner cavity 28 in which said shutter 2 is mounted movably. Said wall 26 has an inlet 30 and an outlet 32 for the fluid, configured to lie opposite the inlet channel 16 and outlet channel 18 respectively of the support 8. In this way it allows circulation of the fluid from said inlet channel 6 to said outlet channel 18 through said inner cavity 28 when said shutter 2 is in the open position. Said protruding part 6 receiving said shutter 2 here has a ribbed configuration.
As shown more clearly in
Said protruding part 6 receiving said shutter 2, more particularly its cavity 28, and the housing 10 of said support 8 are for example cylindrical, said longitudinal extension direction D of said protruding part 6 receiving said shutter 2 then being defined by the axis of the cylinder.
Said shutter 2 is configured to occupy different positions corresponding to different flow rates of said fluid, said positions ranging from a closed position (as shown) to a maximum flow position in which said shutter 10 has been raised in the extension direction D of said protruding part 6 receiving said shutter 2.
Said shutter 2 has an actuation axis intended to extend in the longitudinal direction extension D of said protruding part 6 receiving said shutter 2. More precisely, said shutter 2 here comprises a valve formed by a rod (not visible) and a closing head 40 mounted at the end of the rod. Said valve rod extends in said extension direction D to connect with said kinematic transmission elements at an opposite end of said rod.
The closing head 40 closes or opens the outlet 32 of said protruding part 6 receiving said shutter 2, in order to block or allow the circulation of fluid by cooperating with a valve seat formed by the distal end 35 of said protruding part 6 receiving said shutter 2. Said rod is for example movable in translation in said longitudinal extension direction D, said valve then comprising means (not visible) for converting the movement provided by said kinematic transmission elements—in this case a rotation—into a translation movement. Said means are housed for example at the level of said second zone 38 of said protruding part 6 receiving said shutter 2.
In one variant (not shown), the valve may be replaced by a butterfly valve, an actuating rod of the flap then being directly driven in rotation about its axis by the kinematic transmission elements.
According to the invention, said body 4 is also configured to allow fixing of said valve 1 to said support 8 in a direction T transverse to said longitudinal extension direction D of said protruding part 6 receiving said shutter 2. Said body 4 is again configured to allow a radial tightness between said protruding part 6 receiving said shutter 2 and said support 8. This gives a simple fixing solution, limiting the size of the valve while ensuring a satisfactory tightness.
As shown in detail on
Said O-ring 50 and/or said groove 52 are situated at the level of said first zone 36 and close to said second zone 38 in said longitudinal extension direction D. In other words they are situated at the end of said first zone 36 opposite said distal end 35.
The O-ring 50 is for example made of material based on fluorocarbonated polymer FPM, in particular peroxided FPM and/or Teflon® (PTFE).
Referring again to
Said valve may also comprise fixing means 60 allowing fixing of said body 4 to said support 8 in said transverse direction T. In particular said means comprises an orifice 62 provided in said body, in said transverse direction T, and intended to receive a screw or nut 64, for example a lock nut. Said nut or screw 64 has not been shown in
Said orifice 62 of the fixing means is formed for example in a sleeve 63, here originating radially from said second zone 38 and/or said base 20 of the body 4. At one of its ends, said sleeve defines a rest surface 66 for said screw or nut 64, and/or at the other of its ends a contact surface (not visible) intended to lie opposite the fixing surface 14 of the support 8, preferably flat on flat. Said sleeve 63 comprises ribs 72 formed orthogonally to said transverse direction T.
Said orifice 62 of the fixing means is intended to be situated in the extension of said threaded orifice provided in the support 8 for screwing of said screw or nut 64. It is noted that such an orifice 62, although alone, is sufficient to obtain satisfactory fixing of the valve 1 on its support 8.
Said orifice 62 of the fixing means is oriented to allow fixing of said valve in a screwing direction allowing a screwing tool to avoid the shoulder 24. In other words, as already mentioned in relation to the positioning and orientation of the transverse fixing direction T, said orifice 62 of the fixing means is situated for example tangentially relative to said protruding part 6 receiving said shutter 2, in particular tangentially to said second zone 38, and even more particularly in a plane orthogonal to said longitudinal extension direction D. It is positioned axially between said proximal end 34 and said first zone 36.
Said body 4 is here configured to allow fixing of said valve 1 projecting from said support 8. Said protruding part 6 receiving said shutter 2 may in particular have a greater mass than the other protruding part 22, in order to reduce the overhang.
To limit the effects of the overhang, said body 4 may also comprise one or more reinforcing ribs, in particular oriented orthogonally to said longitudinal extension axis D.
One of said ribs is formed by said shoulder 24, and another 68 of the ribs is formed remote from said shoulder 24 in the longitudinal extension direction. It connects here to an angular extremity 70 of the ribs 72 of said sleeve 63. A material fin 73, here orthogonal to said ribs 24, 68, may furthermore connect said protruding part 6 receiving said shutter 2 and said other protruding part 22.
Said protruding part 6 receiving said shutter 2 may also comprise, in particular at the level of said second zone 38, radial projections 74 intended to form a spacer element between said rest surface 12 of the support 8 and said other rib 68. In other words, said valve rests on said support 8 by means of said radial projections 74.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1258656 | Sep 2012 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2013/052108 | 9/13/2013 | WO | 00 |
