WO2010069781A1

WO2010069781A1 - Duct along which fluid flows with a shut-off flap and method of manufacturing such a duct

Info

Publication number: WO2010069781A1
Application number: PCT/EP2009/066369
Authority: WO
Inventors: Laurent Albert; Sébastien Adenot; Stéphane SORIN; David Nave
Original assignee: Valeo Systemes De Controle Moteur
Priority date: 2008-12-18
Filing date: 2009-12-03
Publication date: 2010-06-24
Also published as: FR2940391B1; FR2940391A1

Abstract

The invention relates to a duct along which a fluid flows with a pivoting shut-off flap (2) driven by a shaft (3) mounted in at least one bearing (4, 4'), the duct comprising an interior surface (11) that guides the flow, characterized in that the bearing (4, 4') has an end surface (41, 41') flush with the interior surface (11) of the duct to ensure continuity thereof. The invention also relates to a method of manufacturing such a duct.

Description

Fluid flow channel with a shutter and method of manufacturing such a conduit

The invention relates to the field of fluid flow conduits closed by a shutter and, more particularly, those used in motor vehicles for transporting gases of an internal combustion engine.

In a conventional manner, with reference to FIG. 1, a shutter 2 is mounted in a tubular pipe of gas 1. The shutter 2 is pivotally mounted about an axis Zv and driven by a shaft 3, s extending along this axis

Zv, to which it is secured, between an open position and a closed position, to control the amount of gas flowing in the pipe 1, traditionally, the shutter 2 is in the form a circular disc from closing the pipe 1 in a plane substantially transverse to the axis of the pipe 1 in the closed position.

The pipe 1 comprises two radial bores 5, 5 ', diametrically opposed, allowing the passage of the drive shaft 3 of the shutter flap 2. As shown in Figure 1, a tubular cylindrical bearing 14, 14' is mounted in each bore 5, 5 'for the support of the drive shaft 3; the latter is mounted in the bearings 14, 14 'which support it and allow its rotation about its axis Zv.

The skilled person who seeks to mount a shutter 2 in a pipe 1 is facing difficulties. It must, on the one hand, design a shutter 2 whose peripheral edge closely matches the inner surface of the pipe 1 and, on the other hand, allow sufficient clearance between the shutter 2 and the pipe 1 to allow the shutter 2 to move in rotation between its open and closed positions, without friction. In a pipe 1 of the prior art as shown in Figure 1, gas leaks may appear more particularly in the zone F located between the edge of the shutter 2 and the inner end of the bearings 14, 14 ' . To limit these leaks, the bearings 14, 14 'are placed in the radial bores 5, 5' of the pipe 1, closer to the shutter 2, so as to reduce the clearance between the edge of the shutter 2 and the bearings 14, 14 '. Nevertheless, if the clearance is too low, friction can occur between the edge of the flap 2 and the end surface, bearings 14, 14 'during the rotation of the flap 2 in the pipe 1. On the other hand if the game is too important as shown in Figure 1, leaks appear in the zone F. It is therefore a dilemma that the skilled person is confronted, not knowing whether to allow a game too weak or too important.

To solve this dilemma, the Applicant proposes a fluid flow pipe with a pivoting shutter driven by a shaft mounted in at least one bearing, the pipe having an internal surface for guiding the flow, characterized in that that the bearing has an end surface flush with the inner surface of the pipe to ensure continuity.

Thanks to the invention, the leaks are reduced, since the end surface of the bearing ensures the continuity of the inner surface of the pipe, that is to say, it completes in its zone allowing the passage of the shaft . Moreover, the rotation of the flap is not impeded because of this surface continuity. In a way, it can be said that from a geometric point of view, the end surface of the bearing and the surface that should have formed the inner surface of the pipe (where the end surface of the pipe extends plateau) are substantially merged, that is to say that they have the same equations and therefore the same form. Preferably, the pipe comprises at least one radial bore of passage of the shaft, opening into the pipe at an orifice and the bearing is mounted in said bore, its end surface extending in the orifice,

The bearing thus extends in the bore to support the shaft in rotation, its end surface "filling" the space formed by the orifice formed by the radial bore opening into the pipe to ensure the continuity of the inner surface of the pipeline.

More preferably, the inner surface having, in sectional view, a curvilinear shape, the end surface of the bearing has, in sectional view, a corresponding curvilinear shape.

Thus, the inner surface and the end surface form a comprehensive and continuous surface for guiding the fluid flow. The risk of leakage is then considerably limited, while the surface seen by the fluid or the flap is continuous regardless of the angular position of the flap.

Since the pipe is of cylindrical shape, the end surface of the bearing is of cylindrical concave shape, preferably with the shape of the cylinder whose channel has the shape.

Preferably, the pipe having, in sectional view, an inner surface in the form of a circle, the end surface of the bearing, in sectional view, has a radius of curvature equal to the radius of said circle. The shape of the surface is thus not only continuous but still identical.

According to a particular embodiment of the invention, the bearing is generally tubular cylindrical. Preferably, the pipe having two diametrically opposite radial bores through which the shaft passes, a bearing is mounted in each bore.

The presence of two bearings mounted respectively in two diametrically opposed bores facilitates the positioning of the shutter in the pipe by allowing a "self-centering" of the shutter during its assembly in the pipe. In other words, the shutter is positioned automatically in the pipe in its position of use.

More preferably, the shutter comprises at least one bearing portion on the bearing regardless of its angular position.

This bearing portion is preferably formed by a portion of the edge of the flap around the passage zone of the shaft.

Preferably, the support portion of the shutter has a shape complementary to the shape of the end surface of the bearing so as to form a sealing area.

The complementarity of the forms advantageously allows to limit the game and, consequently, the risk of leakage, while allowing the relative movement of the parts.

The invention also relates to a method for manufacturing a fluid flow line, comprising an internal surface for guiding the fluid and at least one radial bore for passage of a shaft mounted in a bearing, in which process the bearing in said bore, one end of said bearing being protruding in said pipe and machining the projecting end of said bearing so that the surface of the inner end of the bearing is flush with the inner surface of the pipe to ensure the seal. Thus, the bearing can be machined in its position of use, thereby eliminating manufacturing tolerances and positioning deviations related to mounting; in other words, the bearing is machined "to measure", in situ.

Preferably, the method also comprises the following steps: a shutter flap comprising a tubular chimney passing through the shaft with at least one bearing portion is mounted in the pipe, the support portion of the shaft is abutted. tubular chimney of the shutter with the end surface of the flush bearing in the pipe, so as to align the bearing and the tubular chimney, and the shaft is introduced into the bearing and the duct of the tubular chimney of the shutter. shutter.

Thus, thanks to this method, the bearing fulfills a function of positioning the shutter in the pipe: the chimney first comes to abut at a point of the axis of rotation of the shutter in the pipe, and then simply to straighten the shutter so that the chimney comes to align with the axis of rotation of the flap in the pipe.

More preferably, the fluid flow channel comprising diametrically opposed radial shaft passage bores, a bearing being mounted in each bore, abutting the support portions of the tubular chimney of the shutter flap with the end surfaces of the bearings and the shaft is introduced into a first bearing, the conduit of the tubular chimney of the shutter and the second bearing.

Advantageously, the shutter "self-center" in the pipe when the support portions of the chimney are matched with the end surfaces of the bearings, the axis of the chimney of the flap being automatically aligned with the axis of rotation of the shutter in the pipe. The invention will be better understood with the aid of the appended drawing in which:

- Figure 1 shows a schematic cross sectional view of a fluid flow line closed by a shutter with bearings according to the prior art; - Figure 2 shows a schematic cross-sectional view of a fluid flow line closed by a closure flap with bearings according to the invention;

- Figure 3 shows a perspective view of a pipe, according to the invention, with bearings protruding into said pipe, prior to machining;

- Figure 4 shows the pipe of Figure 3 seen transversely to its main axis;

- Figure 5 shows a perspective view of the pipe of Figures 3 and 4 after machining bearings in said pipe; - Figure 6 A schematically shows a perspective view of the mounting of the bearings in the pipe of Figure 5;

- Figure 6B shows schematically the pipe of Figure 6 A top view, that is to say in the axis of rotation of the shutter;

- Figure 6C schematically shows the pipe of Figure 6A side view, that is to say, orthogonal to the axis of rotation of the flap and the main axis of the pipe;

FIG. 6D diagrammatically represents the ducting of FIG. 6A seen from the front, that is to say in the axis of the pipe and

- Figure 7 shows a shutter adapted to be mounted in a pipe according to the invention.

With reference to FIGS. 2 and 3, a gas flow line 1 of an internal combustion engine is in the form of a tubular duct extending, at least in its portion described, along an axis main Xc. It has an inner surface 11 for guiding the flow. This inner surface 11 is in this case cylindrical.

A shutter shutter 2 is mounted in the pipe 1 to allow its shutter. It is pivotally mounted about an axis Zv orthogonal to the axis of the pipe Xc, this axis being designated Zv axis of rotation of the flap 2. The flap 2 is pivotally driven (rotation about its axis Zv) by a shaft drive 3, to which it is fixed integrally in rotation, between an open position and a closed position, to control the amount of gas flowing in the pipe 1; the drive shaft 3 extends along the axis

Zv.

The shutter shutter 2 is here generally in the form of a circular disc closing off the pipe 1 when it extends, in the closed position, in a plane substantially transverse to the axis of the pipe Xc. The shutter shutter 2 could also be elliptical. For the mounting of the drive shaft 3, the pipe 1 comprises two bores 5, 5 'for the passage of the drive shaft 3, diametrically opposite in the pipe 1 and aligned in the direction of the axis Zv of 2. The bores 5, 5 'are here of cylindrical tabular shape. In each bore 5, 5 'is mounted a bearing 4, 4' in which is inserted a portion of the drive shaft 3 of the shutter 2, thus allowing the support and rotation of the drive shaft 3. By simple convention, the upper bore 5 and the lower bore 5 ', upper bearing 4 and lower bearing 4' will be referred to in reference to the upper and lower positions of FIG. 2.

Referring to Figure 7, the shutter 2 comprises a central tubular chimney 6, extending along the axis Z _v of rotation of the flap 2, arranged to receive the drive shaft 3. The chimney 6 is here of circular inner section, rotation locking means being provided between the shaft 3 and the chimney 6, so that the rotation of the shaft causes a rotation of the shutter thus secured to the rotating shaft; these means may for example comprise a lug of the shaft 3 received in a notch of the chimney 6.

The chimney 6 is here of circular section but it goes without saying that it can be in various forms such as, for example, a square section chimney, rectangular or comprising a flat part to be secured in rotation, by complementarity of shapes. , a drive shaft 3 of adapted section.

Referring to Figure 2, each bearing 4, 4 'is here in the form of a hollow tubular cylinder inserted in a radial bore passage 5, 5' of the pipe 1 and an end surface 41, 41 is flush with the inner surface 11 of the pipe 1 to ensure continuity. In other words, each bearing 4, 4 'having a lateral face and two end faces, the end face 41, 4 T which opens into the pipe 1 has a surface whose shape is arranged to ensure continuity with the surface 11 of Line I. In other words, the bearing 4, 4 'is neither projecting in the pipe 1 nor recessed in the through bore 5, 5'. Still referring to FIG. 2, each bore 5, 5 'opens in the pipe 1 at an orifice 51, 51 'respectively; the inner end surface 41, 41 'of each bearing 4, 4' extends into the corresponding orifice 51, 51 'and forms a surface portion having the shape that the inner surface of the pipe would have if no bore had been pierced.

The end surface 41, 41 'of the bearing 4, 4' which ensures continuity with the inner surface 11 of the pipe 1 may also be called sealing face 41, 41 'because of its function of limiting the clearance (and therefore leaks) between the bearing 4, 4 'and the edge of the shutter flap 2. In this example, the pipe 1 of gas flow is in the form of a cylindrical pipe whose passage section is circular, of radius R, to ensure continuity between the sealing face 41, 41 'of the bearing 4, 4 'and the inner surface 11 of the pipe 1, the sealing face 41, 41' is of concave cylindrical shape, its radius of curvature here being substantially equal to that of the radius R of the circle whose cross-section has the form. In other words, the bearing 4, 4 'is in the form of a cylinder whose sealing face 41, 41' has the shape of a cylinder portion.

With reference to FIG. 7, the invention is even more advantageous when the shutter 2 is, in the particularly advantageous embodiment described, in the form of a shutter 2 comprising a central tubular chimney 6, extending along an axis Z _v , and two lateral wings 7, 8 symmetrical with respect to the axis Z _V} the flap 2 being integral; the lateral fins of the flap 7, 8, are arranged to abut with the inner surface 11 of the pipe 1 when the flap 2 is in the closed position.

Still with reference to FIG. 7, the edge surfaces of the shutter shutter 2 comprise two types of surfaces: a first type of surface comprises two strips 71, 81, each forming the edge of a lateral fin 7, 8, and a second type of surface comprising two portions of sphere 9, 9 '(it will be understood, by simple convention, an upper sphere portion 9 and a lower sphere portion 9', with reference to the upper and lower positions of the shutter of FIG. 7, these positions not prejudging the orientation of the shutter 2 in the pipe 1); the spherical portions 9, 9 'are formed at each end of the chimney 6 and arranged to bear on the sealing face 41, 41' of the bearings 4, 4 'of the pipe 1; they form

"Support portions" of the shutter 2. In this example, each sphere portion is in fact a spherical annular slice 9, 9 '. The term "spherical annular slice 9 _{" means} a surface corresponding to a portion of a sphere and more particularly the portion of a sphere between two parallel planes each intersecting said sphere. Thus, the portions 9, 9 'of the chimney 6 of the shutter 2 are not flat but "spherical", to minimize the clearance between the shutter 2 and the bearings 4, 4', while ensuring their relative movements through the complementarity of their respective bearing surfaces regardless of the angular position of the flap 2.

Thus, the bearings 4, 4 'integrated in the pipe 1 fulfill a dual function. They allow, on the one hand, to support the shaft 3 for driving the shutter shutter 2 in the pipe 1. On the other hand, they allow, because of their positioning and the shape of their surface. end 41, 41 ', to reduce the risk of leakage by limiting the play between their end surfaces 41, 41' and the support portions of the flap 9, 9 ', complementarity of shapes.

A method of forming (or manufacturing) a pipeline with an integrated bearing will now be described. With such a method, the bearings can be adapted to the pipe for which they are intended.

In a first step of the method, standard cylindrical bearings 4, 4 'are respectively inserted into bores 5, 5' of a gas flow pipe 1, the bearings 4, 4 'being inserted from outside the bores. 5, 5 'inwards. These standard bearings 4, 4 'are in the form of hollow tubular rolls with flat end surfaces. After insertion, the outer lateral surfaces of the bearings 4, 4 'are in contact with the inner surfaces of the bores 5, 5'. As shown in FIGS. 3 and 4, the bearings 4, 4 'protrude into the pipe 1, their end protruding into the gas passage zone in the pipe 1, in other words, an end portion bearings 4, 4 ^! extends into the interior volume V of the pipe as shown in FIG.

Then, the protruding end of each cylindrical bearing 4, 4 'is machined so that its end surface 41, 41' thus machined is flush with the inner surface 11 of the pipe 1. The machining of the bearings 4, 4 'is formed by the interior of the pipe 1 by means of a machining tool which is inserted into the pipe 1 so as to machine the projecting end of the bearings 4, 4'. For a tubular pipe 1 of circular passage section, the machining tool, for example a milling cutter or a reamer, is inserted into the pipe 1 parallel to the axis Xc of the pipe 1 until the end machining tool is the right of the bearings 4, 4 '. The machining end is then moved parallel to the axis Z _v of rotation of the shutter 2 to reach a bearing 4, 4 'and machine its projecting end and thus form a concave end surface 41, 41' whose shape complete that of the inner surface 11 of the pipe at the orifice 51, 51 'formed by the radial bore 5, 5' opening into the internal volume V of the pipe 1.

In this example, the end surface 41, 41 'is in the form of a cylindrical concave portion. It ensures the continuity of the inner surface 11 of the pipe 1 at the bearings 4, 4 '. When machining the sealing face 41, 41 'of the bearing 4, 4', the stroke of the machining tool is guided by the inner surface 11 of the pipe 1, the machining end of the the tool coming tangent to the inner surface 11 of the pipe 1.

Alternatively, a preliminary step may consist in producing the pipe 1 from a rough casting, then inserting the standard cylindrical bearings 4, 4 'into this foundry, and finally machining the inside diameter 11 of the pipe to the right diameter. 1 and, in the same operation, to machine the bearings 4, 4 '. The bearings 4, 4 'can also be arranged beforehand in the mold of the foundry gross, the latter coming then overmold on the bearings. It is simply necessary to ensure that, preferably, the raw foundry has an extra thickness relative to the inner surface 11 that is to be obtained in the end, and that the bearings are overmoulded so that they exceed to the interior compared to the inner surface 11 that we want to get. The machining step will then remove the internal extra thickness of the pipe 1 and, with the same machining pass, to machine the bearings 4, 4 '.

Thanks to the preceding steps, the bearings 4, 4 'are machined "to measure" in the pipe 1 to which they are intended, thus guaranteeing a very good level of sealing, independent of the manufacturing or machining tolerances of the pipe 1 , bores 5, 5 'or bearings 4, 4', since the machining is done in situ, after manufacture and assembly of the other elements.

Then, a shutter shutter 2 is introduced into the pipe 1, moving it parallel to the axis of the pipe Xc, and the support portions 9, 9 'of the tabular chimney 6 of the shutter shutter are placed. 2 in correspondence with the sealing faces 41, 41 'of the bearings 4, 4', the bearings 4, 4 'and the tabular chimney 6 being then aligned. In other words, the support portions 9, 9 'of the tabular chimney 6 abut with the end surfaces 41, 41' of the bearings 4, 4 '. The bearings 4, 4 'flush in the pipe 1 thus fulfill a centering function facilitating the positioning of the shutter 2 in the pipe 1. This is called automatic centering or "self-centering" of the shutter shutter 2 in the pipeline 1.

A drive shaft 3 is introduced successively into the upper bearing 4, the duct of the tabular chimney 6 of the shutter flap 2 and the lower bearing.

4 '. The closure flap 2 and the drive shaft 3 are then secured by means of a lug of the shaft 3 received in a notch in the chimney 2 for a rotation of the drive shaft 3 about the axis Zv of rotation of the flap 2 drives the flap 2 in the pipe 1 between its open and closed positions.

With reference to FIGS. 6A-6D, the bearings 4, 4 'integrated in the pipe 1 make it possible to support the drive shaft 3 and to allow its rotation while ensuring the continuity of the inner surface 11 of the pipe 1,

It goes without saying that the invention also applies to a pipe 1 comprising only a single bearing 4. In this case, a bearing portion of the tubular chimney 6 of the shutter shutter 2 is matched with the sealing face 41 of the single bearing 4, the bearing 4 and the tubular chimney 6 then being aligned along the axis of rotation Zv.

It has been described here a shutter 2 whose closure surface is circular but it goes without saying that other forms may also be considered, depending on the shape of the pipe (oblong or elliptical for example).

Whatever the shape of the flap 2 and the pipe 1, the end surface of the (or) bearing (s) is arranged to ensure the continuity of the inner surface 11 of the pipe 1, In particular, the inner surface 11 of the pipe 1 having in sectional view, a curvilinear shape, the end surface has, in sectional view, a curvilinear shape ensuring the continuity, in the mathematical sense, of the curve whose section of the pipe has the shape . The continuity can be ensured by a curve of identical shape, for example a circle, or a shape curve different but continuous with the curve whose section of the channel has the shape at their contact points (for example, an ellipse and a circle). Incidentally, it is noted that one can close a pipe of circular section by an inclined flap whose sealing surface is elliptical in shape; in this case, the end surface of (the) bearing (s) may be circular.

It is also obvious that the driving of the shutter 2 can be achieved by various means (through shaft, pivot on one side of the shutter, etc.).

Claims

claims

1. Fluid flow channel with a pivoting shutter (2) driven by a shaft (3) mounted in at least one bearing (4, 4 '), the pipe having an inner surface (11) for guiding flow, characterized in that the bearing (4, 4 ') has an end surface (41, 41') flush with the inner surface (11) of the pipe to ensure continuity.

2. Pipe according to claim 1, comprising at least one radial bore (5, 5 ') for passage of the shaft (3), opening into the pipe at an orifice (51, 51'), in which the bearing (4, 4 ') is mounted in said bore (5, 5'), its end surface (41, 41 ') extending into the orifice (51, 51').

3. Pipeline according to one of claims 1 and 2 wherein, the inner surface (11) having, in sectional view, a curvilinear shape, the end surface (41, 41 ') of the bearing (4, 4'). ) shows, in sectional view, a corresponding curvilinear shape,

4. Pipe according to one of claims 1 to 3, wherein, the pipe being of cylindrical shape, the end surface (41, 41 ') of the bearing (4, 4') is of concave cylindrical shape, preferably with the shape of the cylinder whose channel has the shape.

5. Pipe according to one of claims 1 to 4, wherein the bearing (4,

4 ') is generally of cylindrical tabular shape.

6. Pipe according to one of claims 1 to 5, comprising two radial bores (5, 5 ') diametrically opposite passage of the shaft (3), wherein a bearing (4, 4') is mounted in each bore (5, 5 ').

7. Pipe according to one of claims 1 to 6, wherein the shutter (2) comprises at least one bearing portion (9, 9 ') on the bearing (4, 4').

8. Pipe according to claim 7, wherein the bearing portion (9, 9 ') of the shutter (2) has a shape complementary to the shape of the end surface (41, 41') of the bearing (4, 4 '), so as to form a sealing area.

9. A method of manufacturing a fluid flow line, having an inner surface (11) for guiding the fluid and at least one radial bore (5, 5 ') for passage of a shaft mounted in a bearing (4). , 4 '), in which method: - the bearing (4, 4') is mounted in said bore (5, 5 '), one end of said bearing (4, 4') being projecting in said pipe;

the projecting end of said bearing (4, 4 ') is machined so that the surface of the inner end of the bearing (4, 4') is flush with the inner surface (11) of the pipe to ensure sealing.

10. The method of claim 9, wherein is mounted in the pipe a shutter (2) comprising a tubular chimney (6) for passage of the shaft (3) with at least one support portion (9, 9 '), wherein

the abutment portion (9, 9 ') of the tubular chimney (6) of the shutter flap (2) is abutted with the end surface (41, 41') of the bearing (4,

4 ') flush in the pipe, so as to align the bearing (4, 4') and the tubular chimney (6), and ~ is introduced the shaft (3) in the bearing (4, 4 ') and the conduit the tubular chimney (6) of the shutter flap (2).

11. The method of claim 10, wherein the pipe (1) fluid flow comprising radial bores (5, 5 ') for passage of the shaft (3) diametrically opposed, a bearing (4, 4'). being mounted in each bore (5, 5 '), the abutment portions (9, 9') of the tubular chimney (6) of the shutter (2) are abutted with the end surfaces (41, 41 ') of the bearings (4, 4'), and

the shaft (3) is introduced into a first bearing (4), the duct of the tubular chimney (6) of the shutter flap (2) and the second bearing (4 ').