EP1517014A1 - Cooling device for the pistons of an internal combustion engine - Google Patents

Abstract

The device has jet nozzles (1a-4a, 1b-4b) for receiving a coolant under pressure. The nozzles (1a-4a) are integrated to a common supply manifold (5a) with which a rigid assembly (6a) is formed. The manifold is associated to a connecting unit (7a) for its hydraulic connection with a coolant feed system provided in an engine. The rigid assembly is associated to a fixing unit for being fixed directly to an engine block. An independent claim is also included for an internal combustion engine comprising a cooling device.

Description

The present invention relates to cooling devices for internal combustion engine pistons, for projecting a fluid of cooling such as oil on an appropriate area of the pistons.

In the internal combustion engines currently being developed, the need for increased power provided by the engines, and the needs increase engine efficiency, require constant improvement engine cooling conditions, and in particular the conditions of piston cooling.

As a result, more and more frequent use of piston cooling in which is associated with each piston of the engine, for cooling, at least one cooling nozzle which projects one or several jets of cooling fluid to the bottom of the piston.

For example, the documents FR 2 745 329, US 4,206,726, EP 0 423 830, US 5,649,505, disclose jet structures of cooling that is fixed to the wall of the engine block by making them communicate with an internal coolant supply pipe, said pipe being machined in the engine block itself and connected to the circuit oil supply provided in the engine.

It is thus necessary to provide, in the engine block, the feed pipe of coolant and the sprinkler adapter ports.

The decision to provide an integrated cooling device for pistons of an engine by sprinklers is a decision that is usually made very upstream in the pre-development phase of the engine. It must be realized including hydraulic design studies of the oil circuit design, and thermal studies of the piston. Sometimes even test engines are specially constructed to validate these calculations.

But once the decision is made not to resort to a circuit of sprinkler cooling, it is practically impossible to reverse because too many elements are to be expected concerning the architecture of the engine itself or concerning the machining means to ensure the adaptation and feeding of cooling nozzles.

Thus, if an engine is not planned initially to be equipped with piston cooling nozzles, an internal supply pipe does not necessarily exist at the desired location, and no machining is planned for the adaptation of the sprinklers. Sometimes even, since nothing has been reflected in this direction initially, the machining of the engine block to implant the sprinklers is purely and simply impossible.

Yet sometimes a builder needs to come back on his initial decision, and desires a cooling function by sprinklers. In this case, for the reasons mentioned above, it is necessary to resume a complete study of the motor, resume validations, which leads to a prohibitive cost that excludes practically the implantation of the cooling device.

Document DE 12 16 014 B discloses a system of cooling for internal combustion engine pistons in which several sprinklers are attached to a common feed ramp with which they form a mechanically rigid assembly. The mechanically rigid assembly is fixed to the engine block by screws, which require specific machining of the engine block. The feed ramp is hydraulically connected to a pump placed nearby, under the engine block. There is no mention of a crankcase inferior.

On the other hand, document JP 06 264742 is known from another device. cooling system for internal combustion engine pistons. Several sprinklers are secured to two parallel common feeding ramps which are fixed together in the bottom of the sump. The position of the sprinklers prevents any precision in the direction of the oil jets, and the jets are necessarily broken by the moving parts of the engine during operation.

The problem proposed by the present invention is to design a new sprinkler cooling device structure by sprinklers, which can be integrated into a motor with no or very little modification on the structure of the engine itself.

The goal is to adapt to an engine whose development is complete, or whose development is already engaged, a piston cooling function by sprinklers without having to take over the actual design of the engine, nor the essential validations that are necessary in any engine development.

The invention results from the observation that the essential difficulty implementation of a jet cooling function lies in the modification of the engine block itself to bring the cooling oil up to the sprinklers. Thus, the invention provides means for supplying oil which can be reported in the engine itself without significantly altering the structure of the engine block.

In the usual engines, a lower oil recovery sump is reported under the engine block containing the moving parts. The lower cover usually carries the oil filter, which is connected to the pressurized oil circuit of the engine by a circuit of which a section is thus accessible in the crankcase inferior. The invention takes advantage of this arrangement, by capturing the oil in a circuit pressurized oil generally present in the area of the sump.

The invention also aims at facilitating the mounting of the cooling in the engine, particularly during the assembly stages of heavy and / or bulky subassemblies of the engine.

• l'ensemble mécaniquement rigide est associé à des moyens d'interface hydraulique pour la connexion hydraulique de la rampe d'alimentation commune à un circuit d'alimentation en liquide de refroidissement prévu dans le carter inférieur,
• les moyens d'interface hydraulique sont agencés pour assurer la connexion hydraulique par l'adaptation du carter inférieur sous le bloc-moteur pour l'obturation de sa face inférieure ouverte,
• l'ensemble mécaniquement rigide comprend des moyens de fixation pour sa fixation au bloc-moteur à l'écart des organes mobiles, indépendamment du carter inférieur.

To achieve these and other objects, the invention provides a cooling device for internal combustion engine pistons, the engine comprising an engine block having an open bottom face closed by a lower casing, the device comprising spray nozzles. cooling adapted to receive a cooling liquid under pressure and to project jets of coolant to the pistons to be cooled, several nozzles being secured to a common supply rail to which they are hydraulically connected while forming therewith a mechanically rigid assembly; according to the invention:

• the mechanically rigid assembly is associated with hydraulic interface means for the hydraulic connection of the common feed ramp to a coolant supply circuit provided in the lower casing,
• the hydraulic interface means are arranged to provide the hydraulic connection by adapting the lower case under the engine block for closing its open bottom face,
• the mechanically rigid assembly comprises fixing means for fixing it to the engine block away from the movable members, independently of the lower casing.

By the fact that the common feed ramp allows the feeding of coolant to the sprinklers without modification of the engine block, the device can be adapted to an already developed engine or pre-development, without having to modify the structure of the engine block, without having to redo the study allowing this modification, and without having to redo the validations necessary results.

Naturally, we can also adapt the cooling structure according to the invention in a motor to be designed.

On the other hand, the mechanically rigid assembly can, despite its space, be easily adapted and fixed under the open motor, then the hydraulic connection is automatically ensured by the adaptation of the housing lower, without additional operation.

According to a first embodiment, the device comprises a single ramp common power supply, carrying the cooling nozzles arranged in line with regard to the row of pistons of an inline engine.

According to another embodiment, the device comprises two ramps common feeders each carrying a line of cooling nozzles arranged in relation to a respective row of pistons of a cylinder engine in V.

The device according to the invention can also easily adapt to other engine geometries, for example W-motors, star motors, or any other geometry with several rows of cylinders.

In a particularly advantageous embodiment, for adaptation in a motor having rotating elements rotatably mounted in bearings, the fastening means comprise transverse fastening tabs arranged to be attached to the lower faces of the motor bearings.

It appears that virtually all combustion engines internally developed have levels in which the crankshaft, and these bearings consist of two main parts assembled to each other after adaptation of the crankshaft. The lower parts bearings have lower faces accessible directly from the under the engine before adaptation of the oil recovery sump. he is thus particularly easy to fix the transverse fixing lugs on the lower faces of the motor bearings, before adaptation of the sump.

For example, in such an engine whose bearings are closed by lower bearing blocks held by threaded fixing rods, the legs of transverse fasteners may include holes for the passage of the rods threads for fixing the lower bearing blocks, rods on which the fastening lugs by locking nuts screwed onto the rods.

Alternatively, the fixing means may comprise tabs of fasteners arranged to be fixed in any other fixed area of the engine block which is easily accessible after setting up the rotating elements and before adaptation of the lower case.

• un tube longitudinal d'alimentation constituant la rampe d'alimentation commune, auquel se raccordent des tubes transversaux dont les extrémités constituent les gicleurs de refroidissement,
• une plaque de fixation, comportant des pattes de fixation transversales, et fixée par brasage, soudage ou collage au tube longitudinal d'alimentation.

In a practical embodiment, it can be provided that the mechanically rigid assembly comprises:

• a longitudinal feed tube constituting the common feed ramp, to which are connected transverse tubes whose ends constitute the cooling nozzles,
• a fixing plate, having transverse fixing lugs, and fixed by soldering, welding or gluing to the longitudinal feeding tube.

Preferably, the fixing plate can be folded in the form of an angle in the corner of which is fixed the longitudinal feeding tube, a first wing of the angle constituting the brackets, a second wing of the angle having transverse extensions parallel to the transverse tubes and of which the end zones are attached to the transverse tubes by brazing, welding or bonding.

According to an advantageous embodiment, which facilitates the assembly, the hydraulic interface means comprise a lower inlet opening communication with the common supply ramp and solidarity with it, and adapted to connect tightly to an upper supply port provided in the lower case, by the assembly movement of the lower case under the engine block, the upper supply port being in communication with the pressurized oil circulation circuit of the engine in the crankcase.

• l'orifice inférieur d'entrée est prévu dans une facette inférieure plane de l'ensemble mécaniquement rigide, dans le plan de joint d'assemblage du carter inférieur au bloc-moteur,
• l'orifice supérieur d'alimentation est prévu dans une facette supérieure plane d'un bloc de connexion du carter inférieur, dans le plan de joint d'assemblage du carter inférieur au bloc-moteur.

One of the difficulties lies in the relative positioning and sealing of the hydraulic connections of the cooling device. Positioning and sealing are facilitated and improved by providing a structure in which:

• the lower inlet opening is provided in a plane lower facet of the mechanically rigid assembly, in the joint plane of the lower casing of the engine block,
• the upper feed port is provided in a planar top facet of a lower casing connection block, in the joint plane of the lower casing to the engine block.

The crankcase seal can thus simultaneously hydraulic connections.

• l'orifice supérieur d'alimentation communique avec un orifice de jonction ouvert vers l'intérieur du carter inférieur dans le bloc de connexion,
• une conduite de liaison est prévue pour être logée dans le carter inférieur et pour raccorder l'orifice de jonction et un orifice de captage du circuit de circulation d'huile du moteur prévu dans la paroi du carter inférieur.

In this case, it is also advantageous to provide that:

• the upper supply port communicates with a junction opening open towards the interior of the lower case in the connection block,
• a connecting pipe is provided to be housed in the crankcase and to connect the junction port and a pickup hole of the engine oil circulation circuit provided in the wall of the crankcase.

Preferably, the upper feed orifice communicates with the engine oil filter oil circulation circuit, upstream or downstream of the filter to oil.

Through a downstream connection, we take advantage of the purification carried out by the oil filter to prevent any impurities entrained in the oil of cooling may clog the nozzles.

The hydraulic interface means may preferably comprise a coolant flow control valve, and at the outlet of the flap, one or more branches to separately feed one or more common feeding ramps depending on whether the engine is in-line cylinders or cylinders according to several lines.

The invention also provides an internal combustion engine, in which which the rotating elements are mounted in an engine block having a face lower open closed by a lower casing, and in which sprinklers of cooling project jets of coolant to the bottom of the pistons, comprising a cooling device as defined above.

• la figure 1 est un schéma de principe d'un dispositif de refroidissement selon un mode de réalisation de l'invention, adapté pour un moteur à cylindres en ligne ;
• la figure 2 est une vue schématique en coupe d'un bloc-moteur à cylindres en ligne, montrant l'adaptation d'un dispositif de refroidissement selon la figure 1 ;
• la figure 3 est un schéma de principe d'un dispositif de refroidissement selon un mode de réalisation de l'invention adapté à un moteur à deux rangées de cylindres enV;
• la figure 4 est une vue schématique en coupe d'un bloc-moteur à cylindres en V dans lequel est adapté le dispositif de la figure 3 ;
• la figure 5 est une vue en perspective des éléments essentiels d'un dispositif de refroidissement selon un mode de réalisation de l'invention pour un moteur à huit cylindres en V ;
• la figure 6 est une vue partielle de la face supérieure d'un carter inférieur de moteur, en perspective, montrant l'adaptation des moyens de connexion de la figure 5 ; et
• la figure 7 est une vue en perspective de la face inférieure d'un bloc-moteur à huit cylindres en V, montrant l'adaptation des rampes d'alimentation communes dans le mode de réalisation de la figure 5.

Other objects, features and advantages of the present invention will become apparent from the following description of particular embodiments, with reference to the accompanying drawings, in which:

• Figure 1 is a block diagram of a cooling device according to one embodiment of the invention, adapted for an inline cylinder engine;
• Figure 2 is a schematic sectional view of an in-line cylinder engine block, showing the adaptation of a cooling device according to Figure 1;
• Figure 3 is a block diagram of a cooling device according to an embodiment of the invention adapted to a motor with two rows of enV cylinders;
• Figure 4 is a schematic sectional view of a V-cylinder engine block in which is fitted the device of Figure 3;
• Figure 5 is a perspective view of the essential elements of a cooling device according to one embodiment of the invention for an eight-cylinder V engine;
• Figure 6 is a partial view of the upper face of a lower motor housing, in perspective, showing the adaptation of the connecting means of Figure 5; and
• FIG. 7 is a perspective view of the underside of an eight-cylinder V-shaped engine block, showing the adaptation of the common supply ramps in the embodiment of FIG. 5.

According to the invention, a cooling device for engine pistons internal combustion engine includes cooling nozzles adapted to be reported in the engine block, these nozzles being integral with at least one ramp common feed that is also intended to be brought back within the engine block.

Thus, Figure 1 schematically illustrates a device for cooling according to one embodiment of the invention, comprising four sprinklers 1a, 2a, 3a and 4a, integral with a common feed ramp 5a with which they form a mechanically rigid assembly generally designated by reference 6a.

Nozzles 1a-4a are hydraulically connected to the ramp common supply 5a.

The common feed ramp 5a is associated with means hydraulic interface 7a for its hydraulic connection to a supply circuit in pressure coolant provided in the lower case, no shown in Figure 1.

In Figure 2, there is a motor block 8, the underside 9 is open for the introduction of the rotating elements such as the rod 10, with a bottom edge 11 plan for receiving a lower housing not shown.

The nozzle 1a, integral with the common feed ramp 5a, is engaged in the intermediate space 12 between the engine block 8 and the elements turners 10, and is connected and connected to the common feed ramp 5a by a tube that is bent appropriately to avoid rotating elements such as the connecting rod 10. The nozzle 1a is oriented to project a jet of liquid from cooling to the bottom of the piston 13 associated with the rod 10 and also schematically represented.

In the embodiment of Figures 1 and 2, the device is designed to be adapted in an inline engine, the cooling nozzles 1a-4a being arranged in line with respect to the pistons of said row of cylinders of the engine. There is then only one common feed ramp 5a, associated with these hydraulic interface means 7a.

As can also be seen in Figure 2, the feed ramp common 5a and the nozzles such as the nozzle 1a, forming the whole mechanically rigid 6a, comprise fixing means 14 for fixing in the engine away from the moving parts such as the connecting rod 10.

In FIGS. 3 and 4, a second embodiment of FIG. cooling device of the invention.

In this second embodiment, we find the elements of the mode previous embodiment, namely jets 1a, 2a, 3a and 4a, associated with a first common feed ramp 5a to form a first set mechanically rigid 6a, with the first hydraulic interface means 7a.

There is also a second common feed ramp 5b carrying a second line of cooling nozzles 1b, 2b, 3b and 4b in forming a second mechanically rigid assembly 6b, with second means hydraulic interface 7b for the hydraulic connection to the supply circuit in coolant provided in the engine. This second embodiment is adapted to be mounted on a motor having two respective rows of V cylinders.

Thus, in FIG. 4, a distinction is made in the engine block 8 piston 13a and a second piston 13b, acting on the same central crankshaft by respective rods 10a and 10b. The cooling nozzle 1a, associated with its common feeding ramp 5a, is adapted in the first space intermediate 12a for projecting a jet of cooling fluid on the bottom of the first piston 13a. Likewise, the second cooling nozzle 1b, associated with the second common feed ramp 5b, is adapted in the second space 12b intermediate to project a jet of coolant into the bottom of the second piston 13b.

Thus, in this second embodiment, the device comprises two common feeding ramps 5a and 5b, each carrying a line of nozzles of cooling, respectively 1a-4a and 1b-4b, arranged with respect to a respective row of pistons of the V-cylinder engine.

Each mechanically rigid assembly 6a or 6b is associated with fixing means 14a or 14b to be fixed directly to the engine block 8.

We now consider the perspective view shown in Figure 5, showing the essential elements of a cooling device according to a embodiments of the invention adapted for implantation in an eight-speed motor V cylinders.

We find the first mechanically rigid set 6a, the second mechanically rigid assembly 6b, and a third interface assembly hydraulic 7 constituted by the hydraulic interface means 7a and the means hydraulic interface 7b.

The mechanically rigid assemblies 6a and 6b have structures similar, symmetrically opposed, on which we find the elements essentials illustrated in Figure 3.

This is how we find the cooling nozzles 1a, 2a, 3a and 4a integral with the first common feed ramp 5a, and the jets 1b, 2b, 3b and 4b fixed on the second common feed ramp 5b.

The structures being identical, we will describe essentially the first mechanically rigid assembly 6a. This set includes a longitudinal tube supply forming the common feed ramp 5a, the tube comprising connectors 51, 52, 53 and 54 on which tubes are fitted respective transverse members 55, 56, 57 and 58, the respective free ends of which constitute the jets 1a, 2a, 3a and 4a.

A fixing plate 60, comprising fixing lugs 61, 62 and 63, is fixed to the longitudinal feed tube forming the common supply rail 5a by brazing, welding, gluing or any other appropriate assembly means. The fixing lugs 61, 62 and 63 are parallel, oriented inward towards the other mechanically rigid assembly 6b, and are each provided with a fixing hole 64, 65 or 66.

In the illustrated embodiment, the fixing plate 60 is further folded into shaped angle in the corner of which is fixed the longitudinal tube power supply constituting the common supply ramp 5a. The first wing of the fixing plate 60 constitutes the fastening lugs 61-63. The second wing angle bracket plate includes transverse extensions respectively 67, 68, 69 and 70, which are parallel to the transverse tubes 55, 56, 57 and 58, and whose end zones 71, 72, 73 and 74 are attached to the tubes 55-58 respectively by soldering, welding, gluing, or any other means appropriate. In this way, the transverse extensions 67-70 constitute stiffening means, opposing any displacement of the nozzles 1a-4a by compared to the rest of the mechanically rigid assembly 6a.

For the hydraulic connection of the common feed ramp 5a, hydraulic interface means 7a are provided comprising, on the ramp 5a common feed, a lower inlet 15a, adapted for sealingly connect to an upper supply port 16a provided, such as illustrated in FIG. 6, in a flat top facet of a connection block 24 of the lower casing 17, in the plane of assembly joint of the lower casing 17. hydraulic connection is ensured by the crankcase assembly movement lower 17 under the engine block 8.

The upper supply port 16a is in communication with the pressurized oil circulation circuit of engine in crankcase 17.

Similarly, for the hydraulic connection of the feed ramp common 5b, there is provided hydraulic interface means 7b comprising a lower inlet port 15b which is adapted to connect tightly to an upper supply orifice 16b provided in a planar upper facet of a connection block 25 of the lower casing 17, in the joint plane lower casing assembly 17.

In the embodiment illustrated in greater detail in FIG. 6, the orifice upper supply 16b communicates with an open junction port 18b towards the inside of the lower casing 17, and adapted to receive in a sealed manner the end of a second connecting line 19b. The second connection line 19b is intended to be housed inside the lower case 17 and to connect the junction orifice 18b with a sensing orifice 20 of the circulation circuit of engine pressure oil provided in the wall of the crankcase 17.

In practice, the sensing orifice 20 communicates with the circuit of flow of oil under pressure from the engine downstream or upstream of the oil filter 21.

It is advantageous to provide a flow control valve 22 coolant. The valve 22 fits on the sensing orifice 20, and delivers the coolant to the second connecting line 19b which leads itself to the junction port 18b itself in communication with the upper supply port 16b communicating with the second ramp common feed 5b, when the lower housing 17 is fitted under the engine block 8.

In the embodiment illustrated in FIGS. 5 and 6, the valve 22 communicates further with a first connecting line 19a, which leads the coolant to a first upper supply port 16a se connecting itself to the first common feed ramp 5a when the bottom casing 17 is fitted under the engine block.

The subassembly constituted by the two connecting pipes 19a and 19b and by the control valve 22 is engaged inside the lower case 17, and fixed by the valve 22 and the two ends of the connecting pipes 19a and 19b which are fixed on the wall of the lower casing 17 for example by screws engaged in the holes of fastening lugs such as the tab 23b.

It is understood that by this arrangement of cooling device Figures 5 and 6, no modification is to be made in the engine block 8 itself. The only modification, to adapt the cooling device to a engine that is not originally planned for this, is to adapt slightly the lower casing 17 to provide or to fix two connection blocks 24 and 25 in which are provided the upper feed orifices 16a and 16b, and a channel communicating to the junction ports such as the orifice 18b. It is necessary also provide the fluid passage at the outlet of the filter 21 for the adaptation of the valve 22 and the supply of filtered cooling fluid. The filter 21 itself is placed in a section of pressurized oil circuit of the lower case 17 connected to the pressurized oil circuit of the engine block, particularly to the pump. In FIG. 6, the respective inlet and outlet orifices 21a and 21b can be distinguished. of this pressurized oil circuit in the lower casing 17, orifices that come in communication with corresponding ports of the engine block when the housing lower 17 closes the engine block.

According to one possible embodiment, the connection block or blocks 24 and 25 may be constituted by a portion of the wall of the lower casing 17 itself, that is to say that they can be monoblock with the lower casing 17.

Alternatively, the connection block (s) 24 and 25 may be fitted and fixed in the lower case 17.

In the embodiment illustrated in FIG. 5, the lower inlet orifices 15a and 15b are simple tubes intended to engage inside the orifice corresponding upper supply 16a or 16b. We understand that this requires precise and delicate positioning of the ends of the tubes facing to the orifices, when the lower casing 17 is fitted under the engine.

To facilitate this assembly operation, it is advantageous to provide that the lower inlet orifice (s) 15a and 15b are provided in a flat bottom facet of the mechanically rigid assembly 6a or 6b, in the plane assembly joint of the lower casing 17 to the engine block. In this way, there is no risk of damaging the ends of the tubes during the assembly of the housing lower 17, and the sealing of the hydraulic interface means can be ensured in the joint plane of the lower casing 17 by the crankcase seal itself provides an outgrowth covering the corresponding facets of the blocks of connection 24 and 25 and the mechanically rigid assembly 6a and 6b.

We now consider the means of fixing ramps common feed or mechanically rigid subassemblies 6a and 6b. he Figure 7, illustrating in perspective the lower face of a engine. The lower face of the engine block 8, facing upwards in the figure, is open, and we distinguish the rotating elements 26, 27, 28 and 29, in four compartments separated by the bearings 30, 31 and 32.

The first mechanically rigid assembly 6a is positioned along on one side of the engine, while the second one is mechanically rigid 6b is positioned along the second opposite side of the engine.

The transverse tubes 55-58 are engaged by penetrating the motor, as shown in the figure, while the 61-63 mounting brackets are shaped to be adapted to the geometry of the engine considered, by fixing on easily accessible areas of the engine block before crankcase adaptation In the case of the motor shown, the fixing lugs 61-63 are oriented transversely to be fixed to the lower faces of the bearings respective 30-32 motor.

It can be seen that the fixing lugs 61-63 have holes for the passage of the respective threaded rods 33, 34 and 35 which ensure the fixing of the lower blocks of bearings, rods on which fixing lugs 61-63 by locking nuts screwed onto the rods (not shown in the figure).

In other engine geometries, we will provide, without leaving the frame of the invention, structures of different fixing means adapted to the structure of each engine, so as not to change the geometry of the engine.

We see that there is no modification to make on the engine block itself for the adaptation of the cooling device according to the invention.

For the adaptation of a cooling device according to the invention, access to the engine by its lower open side, lower housing 17 removed. As can be understood in FIG. 7, it is then easy to introduce the mechanically rigid assemblies 6a and 6b, which are relatively light. We can then easily fix them to the engine block as indicated above, the lower inlet orifices 15a and 15b being automatically located in the plane of joint between the engine block and the crankcase 17. Then adapt the lower casing 17, automatically making the hydraulic connection with the section of oil circuit under pressure of the filter.

The present invention is not limited to the embodiments which have have been explicitly described, but it includes the various variants and generalizations contained in the field of the claims below.

Claims (16)

A cooling device for internal combustion engine pistons, the engine comprising an engine block (8) having an open bottom face (9) closed by a lower casing (17), the device comprising cooling nozzles (1a-4a; 1b-4b) adapted to receive a cooling liquid under pressure and to project jets of coolant to the pistons (13, 13a, 13b) to be cooled, several jets (1a-4a) being integral with a ramp of common feed (5a) to which they are hydraulically connected while forming therewith a mechanically rigid assembly (6a), characterized in that : the mechanically rigid assembly (6a) is associated with hydraulic interface means (7a) for the hydraulic connection of the common feed ramp (5a) to a coolant supply circuit provided in the lower casing ( 17) the hydraulic interface means are arranged to provide the hydraulic connection by adapting the lower casing (17) under the engine block (8) to seal its lower face (9) open, the mechanically rigid assembly (6a) comprises fixing means (14) for fixing it to the engine block away from the movable members (10), independently of the lower casing (17). Cooling device according to claim 1, characterized in that it comprises a single common supply rail (5a), carrying the cooling nozzles (1a-4a) arranged in line with respect to the row of pistons of an engine with cylinders in line. Cooling device according to claim 1, characterized in that it comprises a plurality of common feed ramps (5a, 5b) each carrying a line of cooling nozzles (1a-4a, 1b-4b) arranged in relation to a row respective pistons (13a, 13b) of a multi-line cylinder engine. Cooling device according to any one of claims 1 to 3, for adaptation in a motor having rotating elements rotatably mounted in bearings (30-32), characterized in that the fixing means (14) comprise fixing lugs transverse bars (61-63) arranged to be fixed to the lower faces of the bearings (30-32) of the motor. Cooling device according to claim 4, for adaptation in a motor whose bearings (30-32) are closed by lower bearing blocks held by threaded rods (33-35) for fixing, characterized in that the fixing lugs transverse bars (61-63) comprise holes for the passage of the threaded rods (33-35) for fixing the lower bearing blocks, rods on which the fixing lugs (61-63) are fixed by lock nuts screwed onto the rods. Cooling device according to one of Claims 1 to 5, characterized in that the mechanically rigid assembly (6a) comprises: a longitudinal feed tube constituting the common feed ramp (5a), to which transverse tubes (55-58) are connected, the ends of which constitute the cooling nozzles (1a-4a), an attachment plate (60) having transverse attachment tabs (61-63) and attached by brazing, welding or gluing to the longitudinal supply tube (5a). Cooling device according to claim 6, characterized in that the fixing plate (60) is bent in the form of angle in the corner of which is fixed the longitudinal feeding tube (5a), a first wing of the angle constituting the fastening lugs (61-63), a second wing of the bracket having transverse extensions (67-70) parallel to the transverse tubes (55-58) and whose end zones (71-74) are attached to the transverse tubes (55-58) by brazing, welding or gluing. Cooling device according to one of Claims 1 to 7, characterized in that the hydraulic interface means (7a) comprise a lower inlet opening (15a, 15b) in communication with the common supply rail (5a). , 5b) and secured thereto, and adapted to sealably connect, to an upper supply port (16a, 16b) provided in the lower housing (17), by the assembly movement of the lower housing ( 17) under the engine block (8), the upper supply port (16a, 16b) being in communication with the pressurized oil flow circuit of the engine in the lower housing (17). Cooling device according to claim 8, characterized in that : the lower inlet opening (15a, 15b) is provided in a plane lower facet of the mechanically rigid assembly (6a), in the joint plane of the lower housing (17) to the engine block, the upper supply opening (16a, 16b) is provided in a planar top facet of a connecting block (24, 25) of the lower casing (17), in the joint plane of the sump (17). ) to the engine block. Cooling device according to claim 9, characterized in that the connection block (24, 25) is a portion of the wall of the lower casing (17) itself. Cooling device according to claim 9, characterized in that the connecting block (24, 25) is an insert and fixed in the lower casing (17). Cooling device according to one of Claims 10 or 11, characterized in that : the upper supply opening (16a, 16b) communicates with a connecting orifice (18a) open towards the inside of the lower casing (17) in the connection block, a connecting pipe (19a, 19b) is provided to be housed in the lower casing (17) and to connect the junction port (18a) and a sensing port (20) of the intended engine oil circulation circuit in the wall of the lower housing (17). Cooling device according to claim 12, characterized in that the upper supply opening (16a, 16b) communicates with the oil circulation circuit of the engine oil filter (21), upstream or downstream of the filter with oil (21). Cooling device according to any one of claims 8 to 13, characterized in that the hydraulic interface means comprise a valve (22) for controlling the flow of cooling liquid. Cooling device according to claim 14, characterized in that the hydraulic interface means comprise, at the outlet of the valve (22), a plurality of branches (19a, 19b) for separately feeding a plurality of common feed ramps (5a, 5b) in a multi-line cylinder engine. Internal combustion engine, in which the rotating elements are mounted in an engine block having an open bottom face closed by a lower casing, and in which cooling nozzles project coolant jets towards the bottom of the pistons, characterized in that that it comprises a cooling device according to any one of claims 1 to 15.

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