FR3060700B1 - FLUID CIRCULATION VALVE COMPRISING A SEAL BETWEEN THE VALVE BODY AND A VALVE RECEIVING DEVICE - Google Patents

Abstract

The present invention describes a valve (30) for fluid circulation, in particular for a combustion engine, comprising: - a valve body (1), comprising: a direct contact surface (2) between the valve body (1) and a receiving member (3) of the valve, the direct contact surface for direct thermal exchange between the two parts, ○ a portion (4) projecting from the direct contact surface, the projection (4) being arranged to being inserted into a cavity (31) of the receiving member (3) of the valve (30), ○ A conduit (5) for fluid circulation at least partly in the projecting part (4), - A seal sealing member (6), arranged to seal between the valve body (1) and the valve receiving member (3), the seal (6) being arranged in a groove (7) formed in the direct contact surface (2).

Description

Fluid circulation valve having a seal in a groove

The present invention relates to a fluid circulation valve, in particular an exhaust gas recirculation valve fitted to an automobile combustion engine.

An exhaust gas recirculation valve has a movable shutter for controlling the flow of recirculated gas into the valve conduit. In certain known configurations, the gas flow conduit in the valve is contained in a projecting portion of the valve body. This projecting portion is inserted into a cavity of the body receiving the valve. The inlet and the outlet of the circulation duct open into the projecting part of the valve. On the side of the gas inlet in the valve as on the side of the gas outlet, a seal is present to seal between the valve and the receiving member of the valve. One of the seals can thus cover the entire surface of the valve body surrounding the projecting portion of the valve.

In applications having to operate at high temperatures, it is also known to circulate a heat transfer fluid in the valve body, in order to cool it. Indeed, some components of the valve, such as the electric motor operating the control mechanism of the movable shutter, can be weakened or damaged by too high temperatures.

The presence of a seal over the entire surface of the valve body applied to the receiving member decreases the heat transfer between the valve body and the receiving member. Indeed, the seal interposed between the two surfaces adds an interface on each side of the seal, and thus interposes insulating layers between the two components. In some cases, the temperature of the valve body can thus be greater than the acceptable limit, despite the presence of the cooling circuit. One possibility for the designer to solve this problem may be to increase the passage section of the cooling circuit of the valve body. This solution can be difficult to implement without increasing the size of the valve body.

Another possibility may be to increase the flow rate of cooling fluid without changing the geometry of the cooling circuit of the valve. In this case, a modification of the power supply of the circuit is necessary, which requires a deandardization and is not desirable.

The present invention aims to provide a solution for improving the heat transfer of the valve body to the receiving member of the valve, without having to change the operation of the cooling circuit of the valve body. For this purpose, the invention proposes a fluid circulation valve, in particular for a combustion engine, the valve comprising:

A valve body, comprising: a surface for direct contact between the valve body and a valve receiving member, a protruding portion of the direct contact surface, the projecting portion being arranged to be inserted into a cavity of the valve body; the receiving member of the valve, o a fluid circulation duct, the duct being at least partially comprised in the projecting portion,

A seal, arranged to seal between the valve body and the receiving member of the valve, characterized in that the seal is disposed in a groove formed in the direct contact surface.

Since the seal between the valve body and the valve receiving member is located in a groove, there is a direct contact surface between the two parts. This zone of direct contact allows a direct thermal exchange between the two parts. The receiving member of the valve thus contributes to cooling the valve body, and therefore also the components of the valve. The reliability of valve components is improved.

According to one embodiment, the projecting portion of the valve body extends along an axis perpendicular to the direct contact surface. The insertion of the projecting part into the receiving member is thus facilitated.

Preferably, the projecting portion of the valve body has a generally cylindrical shape.

The protruding part of the valve body and the cavity of the receiving member of the valve are thus easily obtained.

According to one embodiment, a first end of the duct is located at an axial end of the projecting portion.

According to one embodiment, a second end of the duct is located on a side wall of the projecting portion.

This arrangement of the ends of the conduit allows a compact structure.

According to an exemplary implementation of the invention, the fluid flow takes place from the first end of the duct to the second end of the duct.

In a variant, the fluid circulation takes place from the second end of the duct towards the first end of the duct.

Advantageously, the axial end of the projecting portion comprises a seal.

According to one embodiment, the bottom of the groove receiving the seal is flat.

Advantageously, the area of the groove is between 15% and 35% of the area of the direct contact surface.

The little space occupied by the seal makes it possible to improve the direct heat exchange between the valve body and the valve receiving member.

According to one embodiment, the valve body comprises a cooling circuit configured to circulate a heat transfer fluid, the heat transfer fluid exchanging heat with the valve body.

The coolant circulating in the valve body contributes to the cooling of the valve body.

Preferably, at least a portion of the cooling circuit is located opposite the direct contact surface, the cooling circuit and the direct contact surface exchanging heat.

The heat absorbed by the coolant circulating in the cooling circuit can also be discharged to the receiving member of the valve, by heat transfer through the direct contact surface.

Advantageously, more than 60% of a length of the cooling circuit is located vis-à-vis the direct contact surface.

The greater the proportion of cooling circuit capable of allowing a transfer to the direct contact surface, the better the heat transfer.

According to one embodiment, the entire cooling circuit is located vis-à-vis the direct contact surface.

This configuration maximizes heat removal from the valve body.

According to one embodiment, the cooling circuit extends in a direction parallel to the plane of the direct contact surface.

Preferably, the cooling circuit is obtained at least in part by molding the valve body. The insertion of a pin into the mold giving its shape to the valve body makes it possible to easily obtain fluid circulation channels.

According to one embodiment, the cooling circuit is obtained at least in part by machining the valve body.

The machined zones make it possible to obtain a better dimensional accuracy.

Advantageously, the minimum distance between the cooling circuit and the direct contact surface is less than 5 mm.

A small distance between the cooling circuit channel allows a good heat transfer.

According to one embodiment, the heat transfer fluid of the cooling circuit of the valve is common with a cooling circuit of the heat engine.

In other words, the valve body is supplied with the engine engine coolant. The number of specific components is thus reduced, since the coolant circulation pump and the heat exchanger are already present.

Preferably, the direct contact surface is flat.

According to one embodiment, the direct contact surface is made by machining the valve body.

Advantageously, the roughness of the direct contact surface is between 1.5 and 2 Ra.

The roughness is here defined by the measurement criterion Ra, according to ISO 1302. This roughness range allows a good heat exchange while remaining easy to manufacture.

Advantageously, the valve body is obtained by molding.

Preferably, the valve body is metallic.

According to one embodiment, the valve body is made of aluminum.

Preferably, the seal has an annular shape.

According to one embodiment, the periphery of the seal is circular.

Advantageously, the seal is metallic.

This type of seal is compatible with applications where the temperature of the gases exceeds 500 °.

Advantageously, the seal is obtained by cutting and folding a metal strip.

According to one embodiment, the seal is coated with an elastomer layer. The elastomer may be a fluorinated rubber of the FKM type.

The elastomer layer whose seal is coated improves the surface state of the seal and thus improves the seal.

According to one embodiment, the radial profile of the seal comprises three rectilinear portions connected together, a first portion being parallel to a third portion, and a second portion forming an angle of between 30 ° and 45 ° with the first portion. .

The profile of the seal makes it possible to generate a compression force ensuring the seal.

Preferably, the depth of the groove is between 3% and 6% of the width of the groove.

This value ensures effective compression of the seal, allowing a good seal.

Advantageously, the seal comprises holding hooks protruding from the inner periphery of the seal and being oriented towards the center of the seal.

The holding hooks thus bear against the lateral surface of the protruding portion of the valve body, and ensures the maintenance of the seal as the valve is not mounted on the receiving member.

Preferably, the holding hooks are obtained by folding the seal.

According to one embodiment, the seal comprises six holding hooks.

Advantageously, the angular difference between two consecutive hooks is constant.

The maintenance efforts are thus regularly distributed.

According to a preferred embodiment, the valve has a movable valve in translation arranged to control the flow rate of fluid passing through the conduit, the axis of displacement of the valve being perpendicular to the direct contact surface.

This type of valve has a low level of parasitic leakage.

According to one embodiment, the valve is movable between a closed position preventing the passage of fluid in the conduit and a maximum open position.

In one embodiment, opening the valve brings the valve closer to the direct contact surface.

In another embodiment, opening the valve moves the valve away from the direct contact surface. It may be advantageous to adapt the opening direction of the valve to the direction of gas flow. Indeed, having the pressure of the gases which plate the seat valve improves the sealing of the valve.

According to one embodiment, the valve is an exhaust gas recirculation valve between an exhaust circuit and an intake circuit of a combustion engine.

According to one embodiment, the receiving member of the valve is an intake distributor of the combustion engine.

According to one embodiment, the axial end of the protruding part is in direct contact with a cylinder head of the combustion engine. The invention will be better understood on reading the figures, which will show other features and advantages of the invention.

FIG. 1 represents a perspective view of a valve according to one embodiment of the invention,

FIG. 2 illustrates a detail of the body of the valve of FIG.

FIG. 3 is a sectional view of the body of the valve of FIGS. 1 and 2,

FIGS. 4 and 5 are perspective views of the receiving member on which the valve of FIGS. 1 to 3 is mounted,

Figure 6 is a top view of the valve of Figures 1 to 5.

In order to facilitate the reading of the figures, the different elements are not necessarily represented on the scale.

There is shown in Figure 1 a valve 30 for recirculating exhaust gas between an exhaust circuit and an intake circuit of a combustion engine. The engine can propel a vehicle, including an automobile.

The valve is mounted on a receiving member 3, which ensures the mechanical maintenance of the valve 30, and the communication with the various fluid circulation circuits.

As can be seen in Figure 4, the receiving member 3 of the valve 30 is here the inlet distributor of the combustion engine.

The valve 30 comes into contact with the surface 19 of the receiving member. Three screws, not shown, are used to press the valve 30 on the receiving member 3 and to ensure the maintenance of the valve 30.

As shown in FIG. 1, the fluid circulation valve 30 comprises:

A valve body 1, comprising: a direct contact surface 2 between the valve body 1 and a receiving member 3 of the valve, a part 4 projecting from the direct contact surface, the projecting part 4 being arranged to be inserted into a cavity 31 of the receiving member 3 of the valve 30, o a conduit 5 of fluid circulation, the duct 5 being included at least partly in the projecting portion 4,

A seal 6, arranged to seal between the valve body 1 and the receiving member 3 of the valve, characterized in that the seal 6 is disposed in a groove 7 formed in the direct contact surface 2.

The valve body 1 forms the fluid flow conduit 5 and receives the various components of the valve 30. Among these components, there is an electric motor, for controlling the position of a movable shutter by means of a mechanism control. The position of the movable shutter makes it possible to control the flow of exhaust gas flowing in the valve. The position of the shutter is determined by a position sensor. The position sensor may be a magnetic sensor.

The direct contact surface 2 of the valve 30 comes into contact with the surface 19 of the receiving member 3 of the valve 1. Direct contact means that no other mechanical part is interposed between the two surfaces. In particular, there is no seal inserted between the surface 2 and the surface 19. A liquid or pasty body, of the grease or oil type, may optionally be present between the two surfaces 2 and 19. The clamping of the valve 1 on the receiving member 3 ensures the contact between the two parts.

The valve 30 has a movable valve 20 in translation arranged to control the flow rate of fluid passing through the pipe 5, the axis of displacement of the valve 20 being perpendicular to the direct contact surface 2.

The valve 20 is movable between a closed position preventing the passage of fluid in the conduit 5 and a maximum open position. In the closed position, the valve 20 rests on a seat and the flow through the valve is zero, leaks near. The opening of the valve moves the valve 20 away from the direct contact surface 2.

The valve body 1 is metallic. More specifically, the valve body 1 is made of aluminum. The valve body 1 is obtained by molding. The valve body can thus withstand the temperatures of the exhaust gas of the engine. In addition, the valve body 1 is thus a good thermal conductor, and is also easy to mold and machine.

The projecting portion 4 of the valve body 1 extends along an axis D perpendicular to the direct contact surface 2.

The projecting portion 4 of the valve body 1 has a generally cylindrical shape.

A first end 8 of the duct 5 is located at an axial end 9 of the projecting portion 4.

A second end 11 of the duct 5 is located on a lateral wall 12 of the projecting portion 4.

The fluid circulation takes place from the first end 8 of the duct 5 towards the second end 11 of the duct 5. In other words, the exhaust gases enter the valve body 1 in the vicinity of the axial end 9, and emerge by the opening 11 of the side wall 12 of the projecting portion 4. The axial end 9 of the valve 30 is matched with the opening 32 of the inlet distributor, visible in Figure 5. The opening 32 is in communication with the exhaust system of the engine, through a channel passing through the cylinder head of the engine and opening into the intake manifold. The channel has not been shown in Figures 4 and 5. The opening 11 of the conduit 5 is matched with the opening 33 of the engine intake manifold. The exhaust gases are thus readmitted into the intake circuit of the engine. The axial end 9 of the projecting portion 4 comprises a seal 10. The seal is thus ensured between the opening 32 and the opening 33, preventing direct leaks between the exhaust circuit and the circuit. engine intake.

The seal 6 seals between the receiving member of the valve and the valve, and prevents the recirculated exhaust gas leaking outwards by creeping between the surface 19 of the receiving member 3 and the surface 2 of the valve 30.

The seal 6 is disposed on the bottom 14 of the groove 7. Once the valve 30 is assembled on the receiving member 3, the seal 6 is compressed between the surface 2 and the surface 19.

As illustrated in Figure 2, the bottom 14 of the groove 7 receiving the gasket 6 is flat.

The direct contact surface 2 is flat.

The direct contact surface 2 is made by machining the valve body 1.

The roughness of the direct contact surface 2 is between 1.5 and 2 Ra.

The roughness is here defined by the measurement criterion Ra, according to Iso 1302. The area of the groove 7 is between 15% and 35% of the area of the direct contact surface 2.

The flat shape and the surface condition of the parts in contact enables an efficient heat exchange between the valve body and the valve receiving member, which contributes to limiting the temperature of the valve body and consequently the components of the valve body. valve. The seal 6 occupies only the zone adjacent to the periphery of the projecting portion 4. The rest of the support surface between the valve and the inlet distributor is used to allow heat exchange through the direct contact surface 2.

In the example described, and as shown diagrammatically in FIG. 6, the valve body 1 comprises a cooling circuit 15 configured to circulate a heat-transfer fluid, the heat transfer fluid exchanging heat with the valve body 1.

The coolant circulating in the valve body contributes to the cooling of the valve body.

Part of the cooling circuit 15 is located opposite the direct contact surface 2, the cooling circuit 15 and the direct contact surface 2 exchanging heat.

In other words, the cooling circuit 15 passes under the direct contact surface 2, over part of the length of the cooling circuit.

In the example described, more than 60% of the length of the cooling circuit 15 is located vis-à-vis the direct contact surface 2.

Conduction of heat between the cooling circuit and the direct contact surface is thus ensured. Part of the heat absorbed by the coolant circulating in the cooling circuit 15 is thus discharged to the receiving member 3 of the valve 30, by thermal transfer through the direct contact surface 2. In cases where the valve 30 is subjected to particularly high temperatures, the additional cooling capacity provided by the direct contact between the valve 30 and its receiving member 3 may make it possible to avoid resizing the cooling circuit 15 of the valve 30, or to modify the flow rate in the cooling circuit 15. Important additional costs are thus avoided.

In other applications, the heat exchange capacity provided by the direct contact surface 2 can avoid having to implant a cooling circuit in the valve body. Again, a significant extra cost can be avoided, which makes the product more competitive.

The cooling circuit 15 extends in a direction parallel to the plane of the direct contact surface 2. In other words, the distance between the axis of the cooling circuit and the direct contact surface 2 is constant. The heat flow is thus homogeneous.

The minimum distance between the cooling circuit 15 and the direct contact surface 2 is less than 5 mm.

In the example shown, the cooling circuit 15 is obtained at least in part by molding the valve body 1.

The hollow form of the cooling circuit 15 is obtained by inserting during the molding of the valve body one or more pins preventing the liquid metal from filling the mold in certain areas.

The cooling circuit is obtained at least in part by machining the valve body 1.

In particular, the zones receiving the inlet and outlet of the coolant in the valve are machined, to ensure sealing.

The coolant of the cooling circuit 15 of the valve is common with the cooling circuit of the engine.

In other words, the valve body 1 is fed by the cooling fluid of the engine. The number of specific components is thus reduced, since the coolant circulation pump and the heat exchanger are already present.

As shown in Figures 1 and 3, the seal 6 has an annular shape.

The periphery of the seal 6 is circular. The seal 6 is metallic.

This type of seal is compatible with applications where the temperature of the gases exceeds 500 °, which is the case in the application illustrated.

The seal 6 is obtained by cutting and folding a metal strip.

The seal 6 is coated with an elastomer layer. This layer of elastomer eliminates roughness and other surface microscopic defects present on the metal surface. The level of leakage is thus reduced, in other words the seal is improved.

As can be seen in FIG. 3, the radial profile of the seal 6 comprises three rectilinear portions 16a, 16b, 16c interconnected, a first portion 16a being parallel to a third portion 16c, and a second portion 16b forming an angle of between 30 ° and 45 ° with the first portion 16a.

The profile of the seal 6 makes it possible to generate a compressive force ensuring the seal.

As shown schematically in FIG. 2, the depth P of the groove 7 is here between 3% and 6% of the width L of the groove 7.

This value ensures effective compression of the seal, allowing a good seal.

As illustrated in FIG. 3, the seal 6 comprises holding hooks 17 protruding from the inner periphery 18 of the seal 6 and being oriented toward the center of the seal 6.

The holding hooks 17 thus bear on the side wall 12 of the projecting portion 4 of the valve body 1, and maintains the seal as the valve is not mounted on the receiving member. The end of the holding hooks is oriented towards the axial end 9 of the projecting portion 4, to oppose a movement of the seal towards this axial end. The seal 6 is not likely to come off the valve 30 during transport of the valves or during assembly operations on the engine.

The holding hooks 17 are obtained by folding the seal.

According to the example shown, the seal comprises six holding hooks 17. The angular difference between two consecutive hooks 17 is here constant.

According to embodiments not shown, the fluid circulation valve may also comprise one or more of the following characteristics, considered individually or in combination: The axial end of the projecting part may be in direct contact with a cylinder head combustion engine. The opening of the valve 20 can bring the valve 20 closer to the direct contact surface 2. In other words, the valve head enters the duct when the valve opens.

The fluid flow can take place from the second end 11 of the duct 5 to the first end 8 of the duct 5. In other words, the direction of the gas flow is reversed with respect to the example described. The entire cooling circuit 15 is located vis-à-vis the direct contact surface 2.

The cooling circuit 15 can be formed in the receiving member 3 of the valve 30. In this case, the valve 30 is devoid of cooling circuit.

Of course, the invention is not limited to the embodiments described and illustrated, which have been given only as examples.

Claims (10)

1. Fluid circulation valve (30), in particular for a combustion engine, the valve (30) comprising: A valve body (1), comprising: a direct contact surface (2) between the valve body (1); ) and a receiving member (3) of its valve, o a portion (4) projecting from the direct contact surface, the protruding portion (4) being arranged to be inserted into a cavity (31) of the receiving member (3) valve (30), o a conduit (5) fluid circulation, the conduit (5) being included at least partly in the protruding portion (4), A seal (6), arranged for sealing between the valve body (1) and the valve receiving member (3), in that the seal (6) is arranged in a groove (7) formed in the direct contact surface (2). ), the gasket (6) being metallic and being coated with an elastomer layer. 2. The valve according to claim 1, wherein the salient portion (4) of the valve body (1) extends along an axis (D) perpendicular to the direct contact surface (2). 3. A valve according to claim 1 or 2, in which a first end (8) of the duct (5) is located at the axial end (9) of the upright portion (4). 4. Valve seion ia preceding claim, in iiai a second end (11) of the duct (5) is located on a side wall (12) of iia part (4). 5. A valve according to one of the preceding claims, in that the bottom (14) of the groove (7) receiving the seal (6) is piat. 6. A valve according to one of the preceding claims, in the region of the groove (7) is between 15% and 35% of the area of the direct contact surface (2). Valve according to one of the preceding claims, in which the valve body (1) comprises a cooling circuit (15) configured to circulate a heat transfer fluid, the heat-transfer fluid exchanging heat with the valve body (1). ). 8. The valve according to the preceding claim, in which at least a portion of the cooling circuit (15) is located opposite the direct contact surface (2), the cooling circuit (15) and the surface of the direct contact (2) exchanging heat. 9. Valve according to one of the preceding claims, wherein the valve has a valve (20) movable in translation arranged to control the flow rate of fluid passing through the conduit (5), the axis of movement of the valve (20) being perpendicular to the direct contact surface (2). 10. Valve according to one of the preceding claims, wherein the valve (30) is an exhaust gas recirculation valve between an exhaust circuit and an intake circuit of a combustion engine.