WO2019180377A1

WO2019180377A1 - Intake air cooling device for an internal combustion engine

Info

Publication number: WO2019180377A1
Application number: PCT/FR2019/050634
Authority: WO
Inventors: Frédéric WASCAT; Yoann Naudin
Original assignee: Valeo Systemes Thermiques
Priority date: 2018-03-23
Filing date: 2019-03-20
Publication date: 2019-09-26
Also published as: FR3079267B1; FR3079267A1

Abstract

The invention concerns a device for cooling intake air of an internal combustion engine, the cooling device comprising a housing, inside which is housed a bundle body composed of a stack of plates and dissipation devices, the cooling device comprising a docking flange configured to connect the housing to the internal combustion engine, characterised in that the docking flange is swaged.

Description

DEVICE FOR COOLING AN INTAKE AIR OF

INTERNAL COMBUSTION ENGINE

The invention relates to a cooling system for an intake air of an internal combustion engine. The invention finds a particularly advantageous, but not exclusive, application with turbocharged engines.

The automobile, like many other industries, uses heat exchangers to provide the engine with optimum operating conditions.

Cooling a heat engine, and more particularly intake air from a turbocharger outlet, requires the use of heat exchangers to cool the air and to increase the density of the mixture. air / fuel.

Nowadays, a heat exchanger for cooling a supercharged air consists of a housing that contains a heat exchange beam body between the intake air to be cooled and a heat transfer fluid.

It is known to fix the heat exchanger for cooling the intake air of the turbocharged engine against the internal combustion engine via a docking flange.

The docking flange must meet certain conditions to allow the heat exchanger to be perfectly maintained against the internal combustion engine. Indeed, the latter must withstand significant mechanical stresses resulting from the weight, the cantilever and the method of attachment of the cooling device equipped with such a docking flange

In addition, the heat exchanger is placed not far from the combustion chambers where the temperature can reach 700 ° C. The exchange bundle is also traversed by a cooling fluid which is at a temperature of the order of 50 ° C. These two temperatures are far apart and generate significant thermal stresses on the docking flange of the cooling device.

To resist these constraints, the docking flange of the prior art is designed from the metal molding technique.

However, this manufacturing technique has several disadvantages. The manufacture of a piece by metal molding first requires the realization of a mold, which with time wears inevitably. In addition, this manufacturing technique is extremely energy-intensive. Indeed, to mold a part, the metal raw material must be melted, which requires a considerable amount of energy to provide to melt the raw material.

In addition, the metal molding is known to be an imprecise manufacturing technique, which is a disadvantage in the production of metal parts to ensure airtightness with another component, in this case, the cylinder head of the internal combustion engine.

Finally, it is regular to perform a machining recovery of a molded part so as to eliminate roughness on certain surfaces of the molded part. However, it is important that the surface of the docking flange is free of any roughness to ensure an ideal flatness between the surface of the docking flange and the surface of the internal combustion engine against which the docking flange is fixed. This retouching on the molded parts therefore involves a loss of time and greater costs. The invention therefore aims to at least partially overcome the disadvantages of the prior art described above by reducing the manufacturing time, reducing manufacturing costs and reducing the energy required for the production of the flange d docking which ensures the attachment of the cooling device to the internal combustion engine.

The present invention thus relates to a cooling device of an intake air of an internal combustion engine, the cooling device comprising a housing inside which is housed a beam body consisting of a stack of plates. and dissipation devices, the cooling device comprising a docking flange configured to connect the casing to the internal combustion engine, characterized in that the docking flange is embossed.

Stamping is the deformation of the metal raw material into a desired piece of complex shape by the compressive action of a stamping press. This manufacturing technique has many advantages including that of working the metal cold, which avoids spending energy to melt the raw material as requested during a metal molding. In addition, the compressive action does not involve the creation of asperities on the stamped part, which avoids the resumption of machining of its surface, which involves in the prior art additional expenses.

In addition to avoiding the additional expenses mentioned above, this type of forming makes it possible to obtain a better dimensional accuracy of the part. Thus, the docking flange has a more complex shape for fixing the housing against the internal combustion engine, while having a mechanical and thermal resistance at least as good as with the solution of the prior art. In addition, the stamped docking flange has the advantage of being secured to the housing via a method called Nocolok brazing. This process consists of brazing without adding material. Indeed, the material forming the embossed docking flange comprises at least two layers: a core of raw material and a bonding layer for mechanically connecting the docking flange to the housing. This tie layer is characterized by its melting temperature, about 550 ° C, which is lower than the melting temperature of the docking flange core. Thus, during Nocolok brazing, the bonding layer melts and mixes with the surface against which it is supported, to form a single structure, ensuring the mechanical connection and sealing between the two welded surfaces. Thus, the housing and the docking flange, both of which are provided with this bonding layer, are welded when passing through a Nocolok brazing furnace. Then follows a cooling step that solidifies the parts thus linked.

In addition, the manufacturing time of a stamped part is significantly lower than that of a molded part and the rate of production of the stamped parts is greater than that of the molded parts.

The beam body is a heat exchange bundle between the intake air flow and a heat transfer fluid. Intake air flow and heat transfer fluid, including a coolant, both pass through the beam body.

According to one characteristic, the docking flange comprises a folded edge against which the housing is supported. The folded edge thus provides a contact surface ensuring a good connection area and a good seal.

According to one characteristic, the housing bears against an inner face of the folded edge. The folded edge thus forms a seat belt of the housing, surrounding the latter.

The term "internal face" here refers to the face of the folded edge which is in contact with the housing, that is to say the face against which the housing rests and is welded after brazing by the Nocolok process.

The fold of the raw material being made possible by the drawing operation, this folded edge has the advantage of increasing the contact area between the housing and the docking flange, thereby increasing the contact area. and therefore the brazing ability of the housing to the docking flange. Moreover, this folded edge provides a housing holding space against the docking flange visible to the naked eye, which facilitates its verification.

According to one feature, the folded edge comprises at least one stop against which the housing bears. The stops, which result from a deformation of the surface of the docking flange, are easily achievable on a stamped part, as is the case of the docking flange according to the invention. The introduction of the housing into the docking flange is limited at one end by these stops, thus ensuring a positioning of the housing in the docking flange which does not require additional means to ensure their position relative to the 'other. This guarantees a simple way the respect of an essential dimension of the cooling device according to the invention.

According to one characteristic, the beam body comprises at least one pair of plates between which a heat transfer fluid can circulate. Advantageously, the beam body is configured to be traversed in a sealed manner by a coolant liquid.

According to one characteristic, the beam body comprises at least one pair of dissipation devices disposed on either side of the pair of plates.

Indeed, the beam body, which is traversed by the intake air flow, comprises at least a pair of rectangular parallelepiped shaped plates, for example rectangular, between which circulates at least one heat transfer fluid flow. The dissipation devices, of parallelepipedal shape, are placed on either side of the pair of plates. In this way, a dissipation device is located adjacent to a plate and a heat transfer occurs between the intake air stream, which licks the dissipation devices, and the coolant flow that evolves between the two plates. a couple of plates.

According to one characteristic, the docking flange comprises at least one docking edge provided with fastening means configured to secure the docking flange to the internal combustion engine.

By way of example, the fixing means may be orifices enabling the insertion of screws ensuring the attachment of the docking flange on the internal combustion engine.

According to one characteristic, the housing comprises at least four sidewalls surrounding the beam body, at least one of the sidewalls comprising at least one curved edge which is superimposed at least in part on an adjacent sidewall. Before joining the cooling device, these flanks are separate parts from each other. After joining, these parts form the housing.

This curved edge of a flank, allowing the superposition of a first flank on another side, is obtained by stamping a plate. Thus, the superposition of the curved edge of the first sidewall on another side increases the contact surface, which improves the welding between the two superimposed sides and finally improves the sealing of the housing. In the same way as stated above, the soldering is carried out by brazing according to the Nocolok process, during a step simultaneous with the brazing step of the stamped docking flange and the housing.

According to one characteristic, the cooling device comprises a housing holding flange, secured to the housing opposite the docking flange relative to the beam body.

This holding flange keeps the housing flanks in place before the soldering operation. This holding flange also forms a docking zone for a pipe that channels the intake flow from the turbocharger.

According to a method of manufacturing the cooling device of an intake air, at least:

a step of assembling a beam body,

a step of positioning the beam body in a housing,

a step of positioning a docking flange embossed at a first end of the casing,

a step of positioning a holding flange at a second end of the housing, the second end being opposite the first end relative to the housing, and

a simultaneous soldering step at least of the housing, the docking flange and the beam body.

Advantageously, the brazing step allows to connect in one operation the beam body, the housing, the docking flange and the holding flange. The brazing step is carried out by a Nocolok process.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below as an indication in relation to drawings in which

FIG. 1 is a front perspective view of the cooling device of an intake air of an internal combustion engine according to the invention,

FIG. 2 is a perspective view of the docking flange operated in the cooling device which is the subject of the invention;

- Figure 3 is a rear perspective view of the cooling device of an intake air according to the invention.

It should first be noted that the figures show the invention in detail for implement the invention, said figures can of course be used to better define the invention where appropriate.

In the different figures, the identical elements bear the same reference numbers.

FIG. 1 represents a general perspective view of the cooling device 1 of an intake air of an internal combustion engine. Such a cooling device 1 comprises a housing 2, a beam body 3 and a docking flange 4, assembled to each other simultaneously during a brazing step according to a Nocolok method.

The housing 2 comprises four flanks 21, parallel in pairs, for forming a housing 2 of parallelepipedal shape, or cubic. The housing 2 defines an inlet surface 22 and an outlet surface 23 parallel to each other, allowing an intake air flow to pass through the housing 2 in its entirety, that is to say from one side to the other .

Inside the casing 2 is the beam body 3. The beam body 3 consists of a stack of plates 31 and dissipation devices 32. The stack consists of the following: an alternation of a pair of plates 31 and a dissipation device 32. Between the two plates 31 of the pair of plates, a heat transfer fluid flow circulates parallel thereto. In addition, a pair of dissipation devices 32 is disposed on either side of the plates 31, flanking them.

This organization is subsequently repeated along an axis perpendicular to the plates 31, to fill the housing 2 in its entirety.

The flow of intake air passing through the housing 2 passes through the dissipating devices 32, the latter may take the form of fins or spacers. Thus, a heat exchange takes place between the coolant flowing between the two plates 31 and the flow of intake air flowing outside the two plates 31. The heat exchange surface is increased at means of dissipation devices 32.

The docking flange 4 is placed at the exit surface 23 of the casing 2. Like a ring, the docking flange 4 surrounds the casing 2 which rests against a folded edge 41 of the casing flange. 4. Such a folded edge 41 results from a right angle bend of an inner part of the docking flange 4 housing. The casing 2 is inserted inside the docking flange 4 until it is locked against abutments 42 which are formed on the folded edge 4L. A stop 42 takes the form of a tongue made by cutting or deformation of the folded edge 41, which emerges towards the inside of the docking flange 4. A free edge of this stop 42 forms a bearing face against which the housing 2 is brought into contact, during the pre-assembly of the cooling device 1 according to the invention. In this way, the housing 2 is embedded in the docking flange 4.

Subsequently, brazing is performed between the housing 2 and the docking flange 4, at the folded edge 41. Indeed, the inner face 411 of the folded edge 41 of the docking flange 4 is welded to the four flanks 21 of the housing 2 by brazing according to the Nocolok process, ensuring good mechanical strength of the housing 2 against the docking flange 4.

In addition, the docking flange 4 comprises a docking edge 43 on which fixing means 44 are present to allow the attachment of the docking flange 4 against the internal combustion engine. The fastening means 44 are orifices allowing insertion, for example, of a screw which, once tightened, keeps the docking flange 4 against the internal combustion engine. In order to make reliable the tightening of the docking flange 4 against the internal combustion engine, the fastening means 44 are distributed on the docking edge all around the casing 2.

In order to withstand the large mechanical forces generated by the clamping of the cooling device 1 against a face of the internal combustion engine, a peripheral reinforcement 45 is formed on the docking flange 4 during the stamping operation. This peripheral reinforcement 45 takes the form of a right-angled folding of the outer peripheral part of the docking flange 4. In this way, the docking flange 4 has a "U" -shaped section, observed in accordance with a perpendicular section of the docking flange 4 and passing therethrough. The presence of such a peripheral reinforcement 45 significantly increases the mechanical strength of the docking flange 4.

The docking flange 4 also comprises ears where the fastening means 44 are arranged. This is a localized widening of the docking edge 43 which offers the possibility of disposing a nut and a washer therein.

It can be seen that the docking flange 4 is stamped because of the rounding and filleting it comprises at the border between the folded edge 41 and the docking edge 43, for example, or between the docking edge 43 and the peripheral reinforcement 45.

Figure 2 shows a cross-sectional view of the docking flange 4 according to the side accommodating the housing.

The docking flange 4 comprises at its center an open space 46 of surface equivalent to the exit surface of the housing, thus allowing the latter to be inserted into the docking flange 4. The stops 42, coming from the folded edge 41 , act as a limit to the insertion of the housing into the docking flange 4. Once the housing is inserted to the stops 42, its flanks rest against the folded edge 41 so as to create a contact surface 47 between the housing and the docking flange 4. In a later step, a mechanical stirring link according to the Nocolok process is implemented at this contact surface 47, in order to mechanically link the housing to the docking flange 4.

The docking edge 43 is provided with fastening means 44. By way of example, these fastening means 44 may be orifices allowing the insertion of anchoring means of the docking flange 4 against the combustion engine. internal. Unlike the previous connection operation between the housing 2 and the docking flange 4, the latter is fixed against the internal combustion engine by a mechanical compressive action such as, for example, the use of screws and d nuts.

In addition, the thermal stresses imposed by the internal combustion engine on the docking flange 4 are high. These cause significant expansion of the docking flange 4. This is why the docking flange 4 comprises the peripheral reinforcement 45 placed at the outer periphery of the docking flange 4. This peripheral reinforcement 45 consists of a perpendicular fold of a docking edge 43 of the docking flange 4, such a fold being made in the same direction as the folded edge 41 of the docking flange 4. In this way, the docking flange 4 , taking the form of a "U", comprises two right angles 48 which have the major characteristic of being highly resistant to mechanical and thermal deformation.

The docking flange 4 is stamped. This docking flange 4 is the result of a deformation of a flat sheet operated by a punch received in a cavity, punch and cavity being a constituent of a stamping press.

Figure 3 shows a general view of the rear of the cooling device 1 of an intake air. Here is meant, rear with respect to Figure 1, having a view of the front of the cooling device 1.

In the background, it is shown the insertion of the housing 2 inside the docking flange 4, with the presence of the contact surface 47 between the folded edge 41 of the docking flange 4 and a part flanks 21 of the housing 2.

FIG. 3 illustrates a rear face of the docking edge 43.

At the docking edge 43, the fastening means 44 allow the attachment of the docking flange 4 to the internal combustion engine, in particular on the cylinder head of the latter. At the periphery of the docking edge 43, a fold is made, thereby creating the peripheral reinforcement 45. This reinforcement, oriented in the same direction as the folded edge 41, makes the docking flange more resistant to the mechanical forces imposed by the cooling device 1 as such, and not its mounting on the internal combustion engine. In the foreground, the inlet surface 22 of the casing 2 forms the mouth through which the flow of intake air enters inside the casing 2, in order to undergo a heat exchange with the heat transfer liquid circulating in the casing 2. beam body 3. The heat exchange is increased thanks to the presence of dissipation devices 32 which are traversed by the intake air flow. These dissipation devices 32 capture the calories present in the intake air flow and transmit them to the plates 31, and thus to the heat transfer fluid circulating therebetween. The successive stacking of this organization composes the beam body 3.

The casing 2 envelops the beam body 3 via four flanks 21, leaving open the inlet surface 22, which allows entry of the intake air flow, and the outlet surface 23 which allows the output of this same flow of intake air.

In order to fix the flanks 21 between them, the latter are provided, at their ends in contact with the other sides 21, curved edges 24. These curved edges 24 create a large bonding surface between two flanks 21 adjacent. Thus, it is possible to have two longitudinal flanks 21 each provided with two curved edges 24 which cooperate with side flanks 21 flat at their ends. Alternatively, each of the four flanks 21 may comprise a single curved edge 24 associated with the adjacent flank 21.

In a later step, a stirring weld according to the Nocolok process is carried out at this bonding surface between the curved edges 24 and the sides covered by these curved edges 24, in order to mechanically link the flanks 21 of the housing 2 with each other, making at the same time, the housing 2 completely sealed to the flow of intake air flowing in the beam body 3.

FIG. 3 also shows a holding flange 25, one of whose functions is to hold the four flanks 21 together against one another by means of notches 26, placed around the periphery of the holding flange 25. This maintenance is used especially in the pre-assembly phase, before the passage to the brazing furnace provided in the context of the Nocolok process.

This holding flange 25 thus ensures the fixing of the four flanks 21 between them, allowing the sealing of the housing 2. This holding flange 25 also serves as a docking edge for receiving a pipe from the air circuit admission

The holding flange 25 is a piece of complementary shape to the shape of the housing 2. In sectional view, this holding flange forms a "U" within which each flank 21 of the housing 2 is housed.

The holding flange 25 is disposed opposite the docking flange 4, with respect to the 2 of the housing or relative to the beam body 3. The holding flange 25 thus extends in the plane of the inlet surface 22 of the intake air flow, while the embossed docking flange 4 s' extends in the plane of the exit surface 23 of the intake air flow. The stamped docking flange 4 is thus disposed at a first end of the casing 2, along a direction of flow of the intake air stream. The holding flange 25 is in turn disposed at a second end of the housing 2, opposite the first end along a direction of flow of the intake air flow.

It is understood from the foregoing that the present invention provides a cooling member of a flow of air admitted into a heat engine and which passes through a heat exchange beam. This member is intended to be attached to a cylinder head of the heat engine by means of a fastening flange which is made by a stamping process, detectable in that the flange comprises bending and deformation zones which result from this process of stamping. The invention has a certain advantage in the use of a stamped docking flange as it can be associated with the other preassembled parts of the cooling device, prior to the brazing operation performed in a furnace of a Nocolok process.

The invention, however, can not be limited to the means and configurations described and illustrated here, and it also extends to any equivalent means or configuration and any technical combination operating such means. In particular, the shape of the docking flange can be modified without harming the invention, insofar as the cooling device, in fine, fulfills the same functionalities as those described in this document.

Claims

1. Cooling device (1) for an intake air of an internal combustion engine, the cooling device (1) comprising a housing (2) inside which is housed a beam body (3) consisting of a stack of plates (31) and dissipation devices (32), the cooling device (1) comprising a docking flange (4) configured to connect the housing (2) to the internal combustion engine, characterized in that the docking flange (4) is embossed.

2. Cooling device (1) for an intake air according to the preceding claim, characterized in that the docking flange (4) comprises a folded edge (41) against which the housing (2) is supported.

3. Cooling device (1) of an intake air according to the preceding claim, characterized in that the housing (2) bears against an inner face (411) of the folded edge (41).

4. Cooling device (1) of an intake air according to claims 2 or 3, characterized in that the folded edge (41) comprises at least one stop (42) against which the housing (2) bears.

5. Cooling device (1) for an intake air according to any one of the preceding claims, characterized in that the beam body (3) comprises at least one pair of plates (31) between which a heat transfer fluid can circulate.

6. Cooling device (1) for an intake air according to the preceding claim, characterized in that the beam body (3) comprises at least one pair of dissipation devices (32) arranged on either side the pair of plates (31).

Cooling device (1) for an intake air according to one of the preceding claims, characterized in that the docking flange (4) comprises at least one docking edge (43) provided with means fastening means (44) configured to secure the docking flange (4) to the internal combustion engine.

Cooling device (1) for an intake air according to one of the preceding claims, characterized in that the housing (2) comprises at least four sidewalls (21) surrounding the beam body (3), at least one of the flanks (21) comprising at least one curved edge (24) which is superimposed at least in part on an adjacent flank (21).

9. Cooling device (1) of an intake air according to claim 1, characterized in that it comprises a holding flange (25) of the housing (2) secured to the housing (2) opposite the docking flange (4) with respect to the beam body (3).

10. A method of manufacturing a cooling device (1) for an intake air, comprising at least:

a step of assembling a beam body (3),

a step of positioning the beam body (3) in a housing (2),

a step of positioning a docking flange (4) embossed at a first end of the casing (2),

a step of positioning a holding flange (25) at a second end of the casing (2), the second end being opposite the first end relative to the casing (2),

a simultaneous brazing step at least of the housing (2), the docking flange (4) and the beam body (3).