EP0931926A1 - Internal combustion engine with compact intake system - Google Patents

Abstract

The engine's air intake system, incorporating an inlet manifold (23) with a distribution chamber and separate ducts, has the manifold, butterfly valve housing (30) and air filter (50) positioned above its cylinder head cover (1). The front and rear ends of the butterfly valve housing are fitted directly and with seals (32, 31) into corresponding apertures in the air filter and inlet manifold.

Description

The present invention relates to a internal combustion engine intended to equip including a motor vehicle. The current invention relates more particularly to the circuit air intake.

Conventionally the air intake circuit of an engine consists of upstream downstream in the air flow direction of an air filter, a butterfly housing (in the case in particular of spark ignition engines), a formed manifold a cavity or plenum from which a plurality leave of ducts and, provided intake ducts in the cylinder head, these conduits formed in the cylinder head opening into the combustion chambers by holes selectively closed by valves.

Elements of the air intake circuit other than the intake ducts in the cylinder heads are usually housed outside the engine in the engine compartment. Given the evolution of motor vehicle design, the dimensions of this engine compartment are today more and more reduced and so it is important to make this more and more compact air circuit.

Among the different solutions offered, it is known to support the collector engine intake as this is including described in patent n ° FR90-08075, filed by the Applicant, where the solution chosen consists of integrate the intake manifold to the cylinder head cover of the motor. According to this prior art, the intake ducts in the cylinder head are oriented upwards to lead to the face upper part of the breech in the vicinity of one of the longitudinal edges. In this way, the pipes integrated intake manifold to the cylinder head cover can use the full width of the cylinder head cover, the assembly remaining extremely picked up and minimal bulk.

Known solutions according to the prior art however, limit themselves to placing the collector above of the engine, the rest of the air circuit remaining positioned in the engine compartment or coming to hang on to the engine block by means of mounting flanges. Such arrangements remain still too bulky and can be sources of vibrations and therefore noisy.

The object of the present invention is therefore improve the existing state of the art by support the entire external air circuit of the engine by the upper part of the engine.

The internal combustion engine according to the invention is of the type comprising a circuit air intake comprising an air filter, a throttle body and an intake manifold, intake manifold consisting of a cavity distributor and a plurality of pipes to supply the conduits corresponding intake housings in the cylinder head.

According to the invention, the combustion engine internal is characterized in that the collector intake, throttle body and air filter are positioned above the cylinder head cover.

According to another characteristic of the internal combustion object of the invention, the upstream and downstream ends of the throttle body are directly fitted into openings air filter and manifold of admission.

According to another characteristic of the internal combustion object of the invention, the upstream and downstream ends of the throttle body are radially surrounded by an O-ring intended to sealing and maintaining the position of these ends in the corresponding openings air filter and intake manifold.

According to another characteristic of the internal combustion object of the invention, the engine includes a gas decantation chamber casing formed directly from foundry, this settling chamber being defined by a first cavity formed on the upper face of the cylinder head cover and a second shaped cavity complementary in a cover intended for come close said first cavity.

According to another characteristic of the internal combustion object of the invention, the cavity intake manifold dispatcher rests directly on the lid closing the chamber decantation of the crankcase gases provided in the cylinder head cover, a simple bore calibrated through the bottom wall of the cover cooperating with a corresponding opening made through the wall lower next to the distribution cavity allows to recycle crankcase gases directly in the intake manifold.

According to another characteristic of the internal combustion object of the invention, the intake manifold and throttle body are attached directly to the chamber cover decantation of the crankcase gases.

According to another characteristic of the internal combustion object of the invention, the gas decantation chamber cover housing incorporates from foundry an element of gas transfer line to the air intake circuit, this pipe element opening at its end downstream by an end piece projecting from the above the cover, this nozzle being adapted for enter the distributor cavity of the collector admission through a corresponding opening.

According to another characteristic of the internal combustion object of the invention, the gas decantation chamber cover housing incorporates a tubular conduit element opening into the settling chamber and intended to cooperate with an opening corresponding to the air filter, this element of duct for recycling crankcase gases directly into the air filter.

• la figure 1 est une vue en perspective éclatée d'un couvre-culasse de moteur à combustion interne équipé d'un circuit d'admission conforme à l'invention ;
• la figure 2 est une vue similaire à la figure 1 précisant le positionnement du collecteur d'admission et du papillon des gaz sur le couvre-culasse ;
• la figure 3 est une vue en coupe partielle, selon un plan parallèle à l'axe longitudinal du moteur, du couvre culasse et du collecteur d'admission ;
• la figure 4 est une vue en coupe partielle, selon un plan perpendiculaire à l'axe longitudinal du moteur, du couvre culasse, du collecteur d'admission et du filtre à air.

The objects, aspects and advantages of the present invention will be better understood from the following detailed description of an embodiment of the invention given by way of non-limiting example, with reference to the accompanying drawings, in which :

• Figure 1 is an exploded perspective view of an internal combustion engine cylinder head cover equipped with an intake circuit according to the invention;
• Figure 2 is a view similar to Figure 1 detailing the positioning of the intake manifold and the throttle on the cylinder head cover;
• Figure 3 is a partial sectional view, along a plane parallel to the longitudinal axis of the engine, of the cylinder head cover and the intake manifold;
• Figure 4 is a partial sectional view, along a plane perpendicular to the longitudinal axis of the engine, the cylinder head cover, the intake manifold and the air filter.

According to the figures, only the elements necessary for the understanding of the invention have been shown. In addition, for facilitate the reading of the drawings, the same parts bear the same references from one figure to the other.

Referring to Figures 1 to 4, we have schematically shown a cylinder head cover 1 covering the cylinder head 10 of a internal combustion of the multicylinder type intended in particular to equip a motor vehicle. The engine also comprises, in a conventional manner, a casing not shown, formed by a cylinder block with an oil tank at the bottom.

In the same foundry of the cylinder head cover 1 and protruding from the upper side of the latter, an open cavity 2 is formed defining the lower part of the recovery chamber 3 and settling of escaped combustion gases in the crankcase through the different games Operating.

Classically appropriate passages formed through the cylinder block and cylinder head 10 which overcomes it allow to set communication all parts of the crankcase with the cylinder head cover 1 and the cavity 2.

The cavity 2 is closed by a cover 4 coming from foundry which comes to be fixed on the top of the cylinder head cover 1 by appropriate means. This cover 4 has an interior cavity 5 of shape substantially combined with that of the cavity 2, defining the upper part of the chamber decantation 3.

The settling chamber 3 is located thus, according to the embodiment described, shared approximately equally between the cylinder head cover 1 and cover 4. Obviously, it is possible to change the proportions respective of the settling chamber contained in the cylinder head cover 1 and the cover 4.

According to the invention, the collector intake 23, throttle body 30 and filter 50 air from the engine air intake circuit, are arranged above the cylinder head cover 1 and relies on the latter in particular through cover 4.

The intake manifold 23, which is conventionally consists of a distributing cavity or plenum 25 and a plurality of pipes individual 26 intended to supply the conduits correspondents in cylinder head 10, is shaped so that the distribution cavity 25 is positioned substantially in line with the cover 4.

Thanks to the positioning of the collector inlet 23 directly above the cover 4, the connection of the settling chamber 3 to intake manifold 23 can then operate directly without reported pipe. So a simple drilling 12 in the roof of the cover 4 cooperating with an opening 22 made through the lower wall opposite the cavity distributor 25 of collector 23, allows recycle the crankcase gases directly into it. A seal 27 is arranged around opening 22, to be interposed between the intake manifold 23 and cover 4, and thus ensuring the tightness of the assembly.

The intake manifold is attached directly on the cover 4 by means of screws fixing not shown cooperating with flanges 28 carried by the intake manifold 23 and counter flanges 48 arranged on the top of the cover 4. Note that the counter flanges 48 are adapted to also serve as flanges to fix the cover 4 on the cylinder head cover 1.

The cover 4 also integrates from foundry, a pipe element 40 which opens at its downstream end by a nozzle 41 projecting from the top of the cover 4. This tip 41 is adapted to penetrate the intake manifold 23 through opening 22 and lead into the distributing cavity 25 substantially above the orifice 12.

This pipe element 40 can be connected at its downstream end to the circuit of recirculation of crankcase gases to the purging of fuel vapors trapped in the canister or even to the air intake circuit slowed down if the latter is not integrated to the throttle body 30.

The integration of this element of pipe 40 to cover 4 simplifies considerably the connection of the circuit to bring additional gases corresponding to the circuit air intake, since the simple assembly of the collector 23 on the cover 4 ensures this connection.

The intake manifold 23 present by elsewhere, a circular opening 29 formed between the two flanges 28, through the side wall opposite the pipes 26 of the distributor cavity 25 of collector 23. It is directly in this opening 29 which is fitted the downstream end of the throttle body 30. This downstream end is surrounded by an O-ring 31 which ensures perfect sealing between the collector intake and throttle body 30 and the holding this end in position in the corresponding opening 29 of the collector of admission.

The butterfly case 30 just like the intake manifold 23 is directly attached to cover 4 by means of fixing screws not figured cooperating with flanges 33 carried by the butterfly housing 30 and counter flanges 43 arranged on the lateral face opposite the cover 4.

The upstream end of the throttle body 30 is fitted similarly to the downstream end in a corresponding opening 59 of the filter air 50. Similarly, a joint O-ring seal surrounding radially the upstream end of the throttle body 30 ensures the tightness of the assembly between the latter and the air filter 50.

The butterfly case is thus directly connected to the intake manifold on the one hand and the air filter on the other hand without additional connection lines and without special fixing device. The fitting downstream and upstream ends of the throttle body 30 in the opening 29 of the collector respectively intake 23 and opening 59 of air filter 50 suffices to seal the assembly.

The immediate proximity of the air filter 50 cover 4 also makes it possible to operate directly connecting the room from decantation 3 at the intake circuit upstream of the butterfly flap. To do this, the cover 4 integrates a tubular conduit element 45 intended to come directly into a corresponding opening 51 of the air filter 50.

Thanks therefore to the intake circuit according to the invention, the gas recirculation device housing of the type with two branches, one branch bass coming to connect to the intake circuit in downstream of the throttle body 30 and a high branch coming to be connected to the intake circuit upstream of the throttle body 30, connects to the circuit direct admission without recourse to any reported conduct.

Thus, thanks to the invention, the mounting of different components of the circuit air intake and connection of this one to the additional introductory circuits gas (crankcase gas, recirculated burnt gas (EGR), etc.) can operate extremely simple, due to a reduced number of parts, parts obtained mainly from molding and do not requiring only a limited number of operations machining.

Of course, the invention is by no means limited to the embodiment described and illustrated which was only given as an example.

On the contrary, the invention includes all technical equivalents of the means described as well as their combinations if these are performed following his spirit.

Claims (7)

Internal combustion engine type comprising an air intake circuit comprising an air filter (50), a throttle body (30) and an intake manifold (23), said manifold intake (23) consisting of a cavity distributor (25) and a plurality of pipes individual (26) intended to supply the corresponding intake ducts in the cylinder head (10), characterized in that the manifold intake (23), the throttle body (30) and the air filter (50) are positioned above the cylinder head cover (1), the upstream and downstream ends of the butterfly housing being directly fitted into corresponding openings (59,29) of the filter air (50) and the intake manifold (23). Internal combustion engine according to claim 1, characterized in that the upstream and downstream ends of the throttle body are radially surrounded by an O-ring (32,31) intended to seal and maintain position of these ends in the openings corresponding to the air filter (50) and the intake manifold (23). Internal combustion engine according to one any one of claims 1 to 2, characterized in what it includes a settling chamber (3) crankcase gases formed directly from the foundry, said settling chamber (3) being defined by a first cavity (2) formed on the face upper cover (1) and a second cavity of complementary shape (5) formed in a cover (4) intended to come closed said first cavity (2). Internal combustion engine according to claim 3, characterized in that the cavity intake manifold distributor (25) rests directly on the cover (4) closing the chamber decantation of the crankcase gases in the cylinder head cover (1), a single calibrated bore (12) through the bottom wall of the cover (4) cooperating with a corresponding opening (22) formed through the bottom wall opposite the distributing cavity (25) makes it possible to recycle the crankcase gas directly into the manifold intake (23). Internal combustion engine according to one any of claims 3 to 4, characterized in what the intake manifold (23) and the housing butterfly (30) are fixed directly on the cover (4). Internal combustion engine according to one any of claims 3 to 5, characterized in what the cover (4) integrates from foundry a channeling element (40) used for transfer of additional gases to the circuit of air intake, said channeling element (40) opening at its downstream end by a nozzle (41) projecting from the top of the cover (4), said end piece (41) being adapted to enter the distributor cavity (25) of the intake manifold (23) through an opening corresponding (22). Internal combustion engine according to one any of claims 3 to 6, characterized in that the cover (4) incorporates an element of tubular conduit (45) opening into the chamber decantation (3) and intended to cooperate with a corresponding opening (51) of the air filter (50), said conduit element (45) allowing recycle the crankcase gases directly into the air filter (50).

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