EP2789824B1 - Compact cooling device for internal combustion engine and method for manufacturing such a device - Google Patents

Description

TECHNICAL FIELD AND PRIOR ART

The present invention relates to a reduced space cooling device for an internal combustion engine and to a method of manufacturing such a cooling device.

A piston cooling nozzle of an internal combustion engine allows a coolant such as oil to be projected onto an appropriate area of the piston.

Piston cooling nozzles are usually formed by inserts attached to the engine block and communicating with a coolant supply port. The position of the nozzle is accurately determined to provide a jet of cooling fluid directed to a specific area of the bottom of the piston or to a piston gallery entrance. In motor vehicles of the recreational vehicle type, the internal combustion engines are equipped with single nozzles each directing a jet of fluid on a piston.

Nevertheless, it is desirable, in order to increase the cooling efficiency, to have several jets of cooling fluid having identical or different shooting zones.

In the field of heavy goods vehicles or construction machinery, engines are particularly stressed and require a more efficient cooling system. Such a cooling system represented on the figure 1 may have two nozzles per piston; these nozzles are each formed of a tube 102, 104 connected to a feed body 106, the two tubes 102, 104 being substantially arranged one beside the other in the same plane and the free end is oriented towards the area to be cooled. However, these two-jet nozzles comprising two tubes 102, 104 are relatively bulky and, if they can be used in heavy vehicle type vehicles or construction machines, they are not in recreational vehicles or passenger cars for which the lateral space to allow the tubes to access the piston skirt is reduced.

In order to reduce the size of the cooling system capable of supplying two jets per piston, bidirectional nozzles have been developed, the nozzle comprising a single tube and two outlets in order to provide two jets of different orientations.

Such a nozzle is described in the document EP 1 394 376 . Indeed, this nozzle has a small footprint adapted to the motor vehicle recreational vehicle, however it offers a reduced flow compared to the cooling system with two separate tubes and the accuracy of the jets may be less good than that of a system of cooling to two separate tubes.

The document JP H07 317519 discloses a lubricating and cooling device of an internal combustion engine having a main body on which is mounted a set of two ducts, the ducts being in fluid communication with the main body. The two tubes are made jointly.

STATEMENT OF INTENT

It is therefore an object of the present invention to provide a cooling device for improved cooling while providing reduced space and good jet firing accuracy and to provide a simplified manufacturing method of such a device. cooling.

The previously stated purpose is achieved by a cooling device according to claim 1, comprising two separate tubes superimposed, and the cooling device has a small footprint. Furthermore, each tube forms with a supply body a subassembly made separately from the other subassembly, the tubes being oriented prior to the attachment to one another of the two subassemblies. The tubes are then directly oriented correctly and do not require an orientation step for example by folding the tubes after assembly. So we avoids an additional folding step of the tubes requiring the establishment of a tool between the close tubes, which would pose problems of feasibility.

The cooling device according to the present invention is therefore of relatively simple construction, is compact, and offers good accuracy in terms of cooling jets and cooling flow comparable to the device of the state of the art two separate tubes.

It is conceivable to use this cooling device with at least two tubes for cooling with one or two pistons.

The cooling device may comprise more than two separate tubes, the addition of cooling tubes being very simple, for example by superimposing another subset composed of a tube and a feed body.

The present invention therefore relates to a cooling device according to claim 1.

For example, the first and second subassemblies are joined by brazing. Alternatively, the first and second subassemblies are secured by means of a flapper screw.

The first supply body may include the supply port of the cooling device and the second subassembly may be adapted to be supplied with cooling fluid through the first supply body.

In an exemplary embodiment, each first and second subset comprises two tubes.

According to an additional characteristic, the device may comprise means for controlling the flow of the cooling fluid.

Preferably, the cooling device comprises means for fixing to an engine block. In an exemplary embodiment, the attachment means to an engine block are formed by a fixing plate fixed on the first supply body and adapted to be fixed on the engine block. In another embodiment, the valve screw also forms the attachment means to the engine block.

The device comprises orientation means with respect to an engine block. The orientation means are for example carried directly by the first supply body or by a wafer integral with the first supply body. The orientation means may be formed by a pin intended to penetrate into an orifice formed in the engine block.

The present invention also relates to an internal combustion engine comprising a motor unit and pistons slidably mounted in said engine block, and at least one cooling device according to the invention, at least one of the tubes of said cooling device being oriented towards a piston.

The present invention also relates to a method for producing a cooling device according to claim 14.

For example, the conformation of the first tube and the second tube is made by folding.

The step of joining the first and second subassemblies can be achieved by brazing between the supply bodies.

As a variant, the step of joining the first and second sub-assemblies is carried out by means of a valve screw.

The production method may comprise an additional step of shaping the free end of at least one of the first and second tubes after step e).

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 est une vue en perspective d'un gicleur à deux tubes distincts de l'état de la technique,
• la figure 2 est une vue en perspective d'un dispositif de refroidissement à deux tubes distincts selon un exemple de réalisation de la présente invention,
• la figure 3 est une vue éclatée du dispositif de refroidissement de la figure 2,
• la figure 4 est une vue en perspective d'un autre exemple de réalisation d'un dispositif de refroidissement selon la présente invention,
• la figure 5 est une vue en perspective d'un exemple de réalisation d'un dispositif de refroidissement selon la présente invention capable de fournir quatre jets de refroidissement,
• la figure 6 est une vue en perspective d'une variante de réalisation du dispositif de la figure 2, les moyens de fixation au bloc moteur comportant des moyens d'orientation,
• la figure 7 est une vue en perspective d'une variante de réalisation du dispositif de la figure 2,
• la figure 8 est une vue en perspective d'une variante de réalisation du dispositif de la figure 5,
• la figure 9 est une vue en perspective d'une variante de réalisation du dispositif de la figure 2 dans laquelle l'un des tubes présente un pliage au niveau de son extrémité fixé dans l'un des corps d'alimentation,
• la figure 10 est une vue en perspective partielle d'un dispositif de refroidissement de la figure 2 monté sur un bloc moteur.

The present invention will be better understood with the aid of the description which follows and the attached drawings in which:

• the figure 1 is a perspective view of a jet with two separate tubes of the state of the art,
• the figure 2 is a perspective view of a cooling device with two separate tubes according to an exemplary embodiment of the present invention,
• the figure 3 is an exploded view of the cooling device of the figure 2 ,
• the figure 4 is a perspective view of another embodiment of a cooling device according to the present invention,
• the figure 5 is a perspective view of an exemplary embodiment of a cooling device according to the present invention capable of providing four cooling jets,
• the figure 6 is a perspective view of an alternative embodiment of the device of the figure 2 , the attachment means to the engine block comprising orientation means,
• the figure 7 is a perspective view of an alternative embodiment of the device of the figure 2 ,
• the figure 8 is a perspective view of an alternative embodiment of the device of the figure 5 ,
• the figure 9 is a perspective view of an alternative embodiment of the device of the figure 2 in which one of the tubes has a fold at its end fixed in one of the feed bodies,
• the figure 10 is a partial perspective view of a cooling device of the figure 2 mounted on an engine block.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

On the figure 2 , we can see an embodiment of a cooling device with two separate tubes according to the present invention comprising a first tube 2 and a second tube 4 superimposed.

The cooling device comprises a first subset E1 and a second subset E2 joined to one another.

The first subassembly E1 comprises the first tube 2 and a feed body 6. The first tube 2 has a first end 2.1 by which it is fixed on the feed body 6, and a second free end 2.2 for the outlet of the jet of cooling fluid and its orientation towards the piston.

The feed body 6 is hollow and has a first longitudinal end 6.1 intended to be connected to a cooling fluid supply circuit of the internal combustion engine, a second longitudinal end 6.2 intended to feed the second subset E2 in cooling fluid, and a lateral orifice 8 connecting to the first end 2.1 of the first tube 2. The body 6 thus ensures the circulation of the cooling fluid from the first longitudinal end 6.1 to the end 2.2 of the first tube 2 via the lateral orifice 8 and towards the second longitudinal end 6.2.

The second subassembly comprises the second tube 4 and a second feed body 10.

The second feed body 10 has a longitudinal end 10.1 connected to the second longitudinal end 6.1 of the first feed body 6. The second feed body 10 also has a lateral orifice 11 to which the second tube 4 is connected by a first end 4.1. The second tube 4 also has a second end 4.2 through which the jet of cooling fluid is discharged and is directed towards a piston.

The feed body 10 is distinct from the feed body 6 and is integral with it. In the example shown, the feed body 10 has a connecting sleeve projecting from the first longitudinal end 10.1 of the second feed body which engages in the second longitudinal end 6.2 of the first feed body 6. In the In the example shown, the first feed body 6 has the shape of a cylinder of axis X1, the second feed body 10 has the shape of a cylinder of axis X2. The two feed bodies 6, 10 are superimposed and the two longitudinal axes X1, X2 are coaxial.

In the example of Figures 2 and 3 , the supply bodies are superimposed and joined by brazing.

On the figure 3 , we can see an exploded view of the device of the figure 2 , on which the feed bodies 6 and 10 are separated.

For example, the tubes 2 and 4 are attached to the supply bodies 6, 10 respectively by brazing.

The method of manufacturing the cooling device according to the invention will now be described.

In a first step, each subset E1, E2 is produced separately, the first tube is secured to the first supply body 6 by its longitudinal end 2.1, by brazing, and the second tube 4 is secured to the second body of supply 10 by its longitudinal end 4.1, by brazing. At the end of this step, the tubes are usually straight.

In a next step, the tubes are deformed so as to give them a desired orientation with respect to their feed body. In the example shown, it is only a portion of the length of the tube located at the free end of the tube which is deformed, for example by bending, to orient it in a given direction which will be that of the jet. In this example, the tube is not deformed over its entire length.

Alternatively, one could consider deforming the tube from its end connected to the feed body as shown in FIG. figure 9 which will be described below.

The tubes 2, 4 are deformed before assembly and joining of the two subsets E1, E2. Thus the orientation step of the tubes is simplified since the tools can be freely arranged without being hindered by the presence of another tube.

In a next step, when the first 2 and second 4 tubes have the desired orientation, the two supply bodies 6, 10 are secured to each other sealingly. For example, the two bodies are joined by brazing.

Alternatively, it is possible to envisage an assembly by fitting and brazing, for example the second feed body 10 is fitted into the first feed body 6, and soldering takes place. Alternatively, a fitting only may be sufficient. Indeed, for a minimum supply pressure of 15 bar, a fitting assembly can be made so as to remain tight. Orientation means are provided between the two subsets E1, E2, such as an orientation counterfoil, or an orientation pin.

After securing the two sub-assemblies, it is possible to provide an additional step of folding the free end of the tubes to adjust their orientation. It will nevertheless be understood that the deformation of the tubes to fix their orientation is mainly performed before the assembly of the two subassemblies.

On the figure 4 another embodiment of a cooling device according to the invention can be seen. In this embodiment, the second supply body 10 is fitted into the first supply body 6. The fitting is sealed by means of a valve screw 12, screwed by a second longitudinal end 10.2 of the second housing body. supply 10 in the first feed body 6. In the example shown, an end 12.2 of the valve screw 12 protrudes from the feed body 6 and the oil supply is through the valve screw.

As can be seen on the Figures 2, 3 and 4 , the cooling device can be equipped with fastening means 14 to the engine block 16. On the Figures 2, 3 and 4 , the fixing means 14 are, in the example shown, formed by a fixing plate provided with a mounting hole 18 in which is mounted the cooling device, more particularly the first supply body 6. The plate of fixing 14 is also provided with one or more orifices 20 allowing its assembly for example by screwing on the housing of the motor 16 ( figure 10 ).

On the figure 6 , the plate 114 is provided with a pin 22 projecting and which is intended to cooperate with a housing provided in the engine block to ensure the orientation of the cooling device relative to the engine block. The attachment of the cooling device to the engine block is done by means of the valve screw 12. Alternatively, it could be envisaged that the plate comprises, in addition to the orientation pin, one or more fixing holes to the engine block, the screw flap not then used for fixing the cooling device on the engine block.

On the figure 7 we can see an alternative embodiment of the device of the figure 4 , wherein the feed bodies 106, 110 have parallelepipedal shapes, the two feed bodies 106, 110 being at least partly in contact by a plane support. On the figure 7 , the supply body 106 directly comprises an orientation pin 22 for cooperating with the engine block. The two bodies are assembled by means of a valve screw 12. In this embodiment, the valve screw 12 ensures the fixing of the cooling device on the engine block. Other methods of assembly may be provided, such as brazing. Alternatively, fastening means, such as a fixing plate 14, may be implemented to fix the cooling device on the engine block. Orientation means are provided between the two feed bodies 106, 110, such as those described in connection with the Figures 2 and 3 .

It will be understood that any other means of fixing the cooling device on the engine block is usable.

On the figure 5 an exemplary embodiment of a cooling system capable of producing four jets of coolant in four different directions can be seen.

This device is produced in a manner similar to that described above for the exemplary embodiments of the devices of the Figures 2 to 4 . During the production of each of the subassemblies, each of the supply bodies 6, 10 comprises two lateral orifices for evacuation of the coolant discharge fluid, on which a tube 2, 2 ', 4 is fixed, 4 '. In the example shown, each subassembly comprises two diametrically opposed tubes 2, 2 ', 4, 4' and the pairs of tubes 2, 2 ', 4, 4' are superimposed. Nevertheless one could consider that the tubes 2, 2 ', 4, 4' of each subassembly are not diametrically opposed and form between them an angle less than 180 °.

On the figure 8 , we can see a variant of the cooling device of the figure 5 wherein the two feed bodies 106, 110 are parallelepiped shaped. Means of orientation are provided between the two power supply, and orientation means between the cooling device and the engine block are also provided, for example in the form of a pin protruding from the power supply unit 110 and intended to cooperate with the motor unit.

On the figure 9 an alternative embodiment can be seen in which the orientation of one of the tubes 4 is made by performing an additional folding at its end mounted in the second feed body 10. Such a folding could be carried out on the In addition, such folding could be carried out on one or more tubes of the devices of the figures 7 or 8 .

One could also consider that the tubes of the two subassemblies are not contained substantially in the same vertical plane but are contained in two separate planes.

On the figure 10 , we can see the cooling device of the figure 2 mounted on a motor block 16 and producing two jets oriented towards the bottom of a piston 22 of the internal combustion engine. The cooling device is assembled on the engine block 16 by means of a fixing plate 14. It is then possible to realize the small space occupied by this cooling device, which makes it particularly suitable for use in an engine block of a recreational motor vehicle or a private car and any vehicle having a lateral space to access the piston skirt having reduced dimensions.

The cooling device may also comprise means for inhibiting the circulation of the cooling fluid as long as the pressure of the cooling fluid has not exceeded a determined threshold value. For example, these means are formed by ball or piston valves. Such means are mounted for example in the first supply body, and thus control the supply of the two tubes 2, 4 simultaneously.

With the present invention, it is possible to insert cooling devices in small spaces of motor vehicle engines while ensuring a proximity with the rotating elements. Indeed cooling devices having a very small footprint, they can be put at the ready of the rotating elements that it is desired to cool. In addition, because of its process embodiment, it provides a great flexibility in the targeting angles of each of the jets and a high accuracy thereof.

The tubes of a cooling system can be convergent, divergent, or intersecting. In addition they can be used to cool a piston or more pistons. In addition, it can be envisaged that the cooling device comprises more than two tubes for example three, the three tubes, for example, being oriented towards the same piston.

Moreover, the cooling device may comprise more than two subassemblies, for example three or more. In the case of three subassemblies, the second feed body then has substantially the shape of the first feed body and the third feed body to that of the second feed body of the feed device. figure 2 or that of the figure 4 depending on the assembly mode of the subsets. The assembly can then be made for example by soldering between the first and second subassemblies and by means of a valve screw between the second and third subassemblies, or only by brazing between all the subassemblies or only by a flapper screw.

Claims (19)

1. A device for cooling a piston for an internal combustion engine of a motor vehicle comprising a connecting end, forming a feed aperture, connecting to a cooling fluid feed system and at least one first end and one second end for evacuating cooling fluid towards one or more areas for cooling, said cooling device comprising at least one first and one second subassembly (E1, E2) superposed on one another, the first subassembly (E1) comprising a first feed body (6) with a longitudinal axis (X1), connected to the feed aperture and a first tube (2) connected to the first feed body (6) by brazing, one free end of which (2.2) forms the first evacuation end, the first tube (2) extending laterally relative to the first feed body (6) and being shaped so as to have a desired orientation, the second subassembly (E2) comprising a second feed body (10) connected to the feed aperture and a second tube (4) connected to the second feed body (10) by brazing, of longitudinal axis (X2), one free end of which (4.2) forms the second evacuation end, the second tube (4) extending laterally relative to the second feed body (10) and being shaped so as to have a desired orientation, the first (6) and second (10) feed bodies being securely attached to one another in sealed fashion, and where their longitudinal axes (X1, X2) are coaxial, said cooling device also comprising means for orientating between the first sub-assembly and the second sub-assembly and means for the orientation relative to an engine block.
2. A cooling device according to claim 1, in which the first and second subassemblies (E1, E2) are securely attached by brazing.
3. A cooling device according to claim 1, in which the first (E1) and second (E2) subassemblies are securely attached by means of a valve-bolt assembly.
4. A cooling device according to claim 1, 2 or 3, in which the first and the second subassembly (E1, E2) are securely attached by press-fitting.
5. A cooling device according to one of claims 1 to 4, in which the first feed body (6) comprises the feed aperture of the cooling device and the second subassembly (E2) is intended to be fed with cooling fluid through the first feed body (6).
6. A cooling device according to one of claims 1 to 5, in which each first (E1) and second (E2) subassembly has two tubes (2, 2', 4, 4').
7. A cooling device according to one of claims 1 to 6, comprising means for controlling the flow of the cooling fluid.
8. A cooling device according to one of claims 1 to 7, comprising means for attachment (14) to the engine block.
9. A cooling device according to claim 8, in which the means (14) of attachment to an engine block are formed by a securing plate (14) attached to a first feed body (6) which can be attached to the engine block.
10. A cooling device according to claims 4 and 8, in which the valve-bolt assembly forms the means of attachment to the engine block.
11. A cooling device according to one of the claims 1 to 10, in which the means for the orientation with respect to the engine block are supported directly by the first feed body and by a plate which is securely attached to the first feed body.
12. A cooling device according to one of the preceding claims, in which the means for the orientation are formed by a pin intended to penetrate into an aperture formed in the engine block.
13. An internal combustion engine comprising an engine block and pistons installed such that they can slide in said engine block, and at least one cooling device according to claims 1 to 12, at least one of the tubes of said cooling device being pointing towards a piston.
14. A manufacturing method for manufacture of a cooling device according to one of the claims 1 to 12, comprising the following successive steps:

    a) construction of a first subassembly (E1) comprising a first feed body (6) fitted with a feed aperture intended to be connected to a cooling fluid feed system, and at least one first tube (2), said first tube (2) being connected by brazing to the first feed body (6),

    b) construction of a second subassembly (E2) comprising a second feed body (10) comprising a feed aperture (10.1) intended to be connected to a cooling fluid feed system, and at least one second tube (4) connected by brazing to the second feed body (10),

    c) shaping of the first tube (2) so as to give it a given orientation,

    d) shaping of the second tube (4) so as to give it a given orientation,

    e) assembly and secure attachment of the two subassemblies (E1, E2) such that the first (6) and second (10) feed bodies are secured to each other in a leaktight manner et their longitudinal axis' (X1, X2) are coaxial, the method also comprising before step e) the manufacturing of the means for orientating the first and second subassemblies and of the means for the orientation with respect to the engine block.
15. A manufacturing method according to claim 14, in which the first tube (2) and the second tube (4) are shaped so as to give them a given orientation before the two subassemblies (E1, E2) are assembled.
16. A manufacturing method according to claim 15, in which the first tube (2) and the second tube (4) are shaped by bending.
17. A manufacturing method according to claim 14, 15 or 16, in which the first and second subassemblies (E1, E2) are securely attached to one another by brazing between the feed bodies.
18. A manufacturing method according to claim 14, 15 or 16, in which the first and second subassemblies (E1, E2) are securely attached to one another by means of a valved-bolt assembly.
19. a manufacturing method according to one of claims 14 to 18, comprising an additional step: f) of shaping of the free end of either or both of the first and second tubes after step e).

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