OUTDOOR AIR VENTILATION DEVICE FOR A TOP AND BOTTOM ENGINE

Abstract

A ventilation system (1) for an internal combustion engine of a motor vehicle comprising at least one outside air inlet (3), outside air filtration means (4), and at least one common duct (5) communicating with the filtration means (4) and capable of distributing the filtered outside air to outside air distribution elements (6a, 6b, 6c) to the engine. The ventilation system (1) comprises at least two distribution elements (6a, 6b) distributing outside air into a cylinder block of the engine, preferably at two opposite points, and at least one distribution element (6c) distributing outside air into a cylinder head cover of the engine. Figure for the abbreviation: Fig 1

Description

Title of the invention: OUTDOOR AIR VENTILATION DEVICE FOR AN UPPER AND LOWER MOTOR technical field

[0001] The present invention relates to internal combustion engines for motor vehicles and relates in particular to spark-ignition internal combustion engines operating on hydrogen.

[0002] Each fuel has a lower explosive limit and an upper explosive limit. The explosive limits define the range of fuel concentration in air within which the fuel ignites. Below the lower explosive limit, there is not enough fuel for the mixture to ignite, and above the upper explosive limit, there is not enough air for the mixture to ignite.

[0003] The lower explosive limit of hydrogen is 4%, meaning that when there is a concentration of 4% or more of hydrogen in the air, the hydrogen ignites and can cause an explosion. Its upper explosive limit is 75%, meaning that when there is a concentration of at least 75% hydrogen in the air, the mixture does not ignite.

[0004] LPG fuel, consisting mainly of methane, has an explosive range of between 5% and 15%, and diesel fuel, consisting mainly of diesel fuel, has an explosive range of between 0.6% and 6.5%.

[0005] Hydrogen is an extremely flammable and reactive fluid, with a higher flammability than gasoline, diesel, LPG, or CNG, for example, because it has a wide explosive range. Hydrogen is therefore a particularly dangerous fluid, especially when used in enclosed spaces. During engine operation, leaks occur, and fuel is released into the lower part of the engine (also called the "crankcase"), which is delimited by a cylinder block and a lower engine casing that seals the cylinder block at its lower end.

[0006] Thus, in order to avoid combustion in the closed volumes of the engine, it is necessary to have an efficient ventilation system which dilutes the gases in the engine crankcase and reduces the fuel concentration.

[0007] A system for diluting engine crankcase gases with fresh air by means of a pump located on an engine oil separator circuit is known from unexamined patent application FR 23 00437. Downstream of the air filter, this pump draws clean air from the engine's air intake circuit and sends it to the lower crankcase to dilute the gases.

[0008] Such a system is, however, difficult to implement from a technical and financial point of view. Moreover, this system is primarily aimed at regulating the airflow but does not aim to distribute it optimally throughout the engine's cylinder block, and the upper part of the engine (also called the "cylinder head"), delimited by a cylinder head and a cylinder head cover that covers the cylinder head at its upper part, is not affected by the ventilation. Description of the invention

[0009] The present invention aims to overcome the aforementioned problems and, in particular, to efficiently dilute the gases in the engine crankcase, taking into account the distribution of air throughout the engine.

[0010] The invention therefore relates to a ventilation device for an internal combustion engine of a motor vehicle comprising at least one outside air inlet, outside air filtration means, at least one common duct which communicates with the filtration means and which is capable of distributing the filtered outside air into outside air distribution elements towards the engine.

[0011] This device includes at least two distribution elements that distribute outside air into a cylinder block of the engine, and at least one distribution element that distributes outside air into a cylinder head cover of the engine.

[0012] Advantageously, said distribution unit comprises at least one outside air pipe equipped with at least one non-return valve.

[0013] Said distribution unit includes at least one connection point intended to be connected to a connector of the motor.

[0014] According to one embodiment, the two connection points of the two distribution elements distributing outside air into a cylinder block of the engine are connected to two connectors of the cylinder block of the engine, these connectors being located at two opposite locations of the engine.

[0015] Advantageously, a cylinder block connector is located on, or near, a distribution face of the engine, and a cylinder block connector is located on, or near, a coupling face of the engine.

[0016] According to one embodiment, the connection point of the distribution element distributing outside air into a cylinder head cover of the engine is connected to a connector of the cylinder head cover of the engine.

[0017] Advantageously, the outside air intake allows fresh air to be injected inside the engine and particularly into its isolated volumes, such as the cylinder block and the cylinder head cover.

[0018] The outside air intake and the outside air filtration means are separate from those of an engine air intake circuit which allows the air to be filled engine combustion chambers.

[0019] In one embodiment, said engine is a hydrogen-powered motor vehicle internal combustion engine.

[0020] The invention also relates to an engine comprising a ventilation device as defined above.

[0021] The invention further relates to a motor vehicle comprising an engine as defined above, which includes a ventilation device as also defined above. Brief description of the drawings

[0022] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0023] - Fig. 1 is a schematic view of a motor ventilation device including three outside air distribution units;

[0024] - Figure [Fig.2A] is a schematic view of the connectors on the cylinder housing of the engine;

[0025] - Figure [Fig.2B] is a schematic view of the connector on the cylinder head cover of the engine ;

[0026] - Figure [Fig.3A] is a schematic view of the ventilation device integrated on the motor, its connection points being linked to the motor connectors;

[0027] - Figure [Fig.3B] is a schematic view of the ventilation device integrated on the motor, its connection points being linked to the motor connectors; and

[0028] - Figure 4 is a simplified schematic view of a ventilation device engine comprising five external air distribution components. Detailed description

[0029] In [Fig.1], a ventilation device for an internal combustion engine of a motor vehicle, designated by the numerical reference 1, is shown. This device 1 is intended to ventilate a spark-ignition internal combustion engine 2, and particularly a spark-ignition internal combustion engine 2 operating on hydrogen.

[0030] Hydrogen is a highly flammable and reactive fuel with a wide explosive range. During the operation of the engine 2, fuel leaks occur in the engine 2 crankcase. Therefore, to prevent abnormal combustion in a hydrogen-powered engine 2, an effective ventilation device 1 is required that dilutes the gases in the engine 2 crankcase and reduces the fuel concentration in the enclosed spaces of the lower and upper parts of the engine 2.

[0031] The ventilation device 1 includes at least one air inlet 3, outside air filtration means 4, at least one common duct 5 which communicates with the filtration means 4, and at least three distribution members 6a, 6b, 6c which distribute outside air into the engine 2.

[0032] The air intake 3 allows outside air to be drawn in and injected into the engine 2, more specifically into a cylinder block 7 in the lower part of the engine, and into a cylinder head cover 8 in the upper part of the engine. The cylinder block and the cylinder head cover of the engine are illustrated in Figures 2A and 2B.

[0033] The filtration means 4 recover the outside air captured by the air inlet 3 and the filter. In particular, they prevent particles of dirt and dust harmful to the operation of the engine from infiltrating the engine 2.

[0034] The common duct 5 communicates with the filtration means 4 and allows the filtered outside air to be distributed into the distribution members 6a, 6b, 6c via a distribution means 9.

[0035] Advantageously, the air inlet 3 and the filtration means 4 of the ventilation device 1 are independent, i.e., separate, from the air inlet and filtration means of the air intake circuit which allows the combustion chambers of the engine 2 to be filled with air. Indeed, in the case where the ventilation device 1 shares the same air inlet 3 and the same filtration means 4 as the air intake circuit, the common duct 5 which is mounted downstream of the common filtration means 4 is subjected to a greater negative pressure due to the pressure drop in the filtration means and the suction of air by the engine 2. As a result, the circulation of ventilation air towards the bottom of the engine and towards the top of the engine is more difficult.

[0036] The ventilation device 1 illustrated in [Fig. 1] comprises two distribution elements 6a, 6b which distribute outside air into the cylinder block 7 of the engine 2, and a distribution element 6c which distributes outside air into the cylinder head cover 8 of the engine 2. These distribution elements 6a, 6b, 6c allow filtered outside air to be distributed into the engine 2, on the one hand into the lower engine, and on the other hand into the upper engine. It is possible that the ventilation device 1 may comprise more than three distribution elements 6a, 6b, 6c.

[0037] Each distribution unit 6a, 6b, 6c comprises at least one outside air pipe 10 equipped with at least one non-return valve 11, allowing control of the direction of outside air. Advantageously, the pipes 10 are flexible pipes.

[0038] Each distribution element 6a, 6b, 6c also includes at least one connection point 12a, 12b, 12c intended to be connected to a connector of the motor 2. A connection point 12a, 12b, 12c is a fitting which may include bulging ends, fir tree-type ends or ringed ends.

[0039] The motor includes several connectors 13a, 13b, 13c which provide the connection with the connection points 12a, 12b, 12c of the outside air distribution components 6a, 6b, 6c. These connectors 13a, 13b, 13c are shown in Figures 2A and 2B, according to one embodiment.

[0040] In [Fig. 2A], two connectors 13a, 13b of the engine are shown, relating to the ventilation of the lower engine. These connectors 13a, 13b are located in the cylinder block 7 of the engine 2, at two opposite points. Their distance allows the ventilation device 1 to ventilate the engine 2 more effectively. Indeed, by injecting outside air into the engine 2 at two distant points, the fuel is diluted more quickly throughout the cylinder block 7 of the engine 2.

[0041] Preferably, a first connector 13a is located on a distribution face of the cylinder block (as illustrated in [Fig. 2A]) or, alternatively, on a point on a side face of the cylinder block located near the distribution face, and a second connector 13b is located on a coupling face of the engine or, alternatively, on a point on a side face of the cylinder block located near the coupling face (as illustrated in [Fig. 2A]). Such an arrangement of the connectors 13a, 13b allows for more efficient ventilation of the central cylinders of the engine.

[0042] With reference to [Fig.2B], the engine connector 13c is located in the cylinder head cover 8 of the engine 2, allowing ventilation of the upper volumes of the engine 2.

[0043] Figures 3A and 3B represent the integration of the ventilation device 1 on the engine 2. When the connection points 12a, 12b, 12c of the ventilation device 1 are connected to the connectors 13a, 13b, 13c of the engine 2, the lower part of the engine 2 is ventilated by means of the connection points 12a, 12b connected to the cylinder block 7, and the upper part of the engine 2 is ventilated by means of the connection point 12c connected to the cylinder head cover 8.

[0044] Fig. 3A illustrates the ventilation device 1 integrated on the engine 2 by means of a connection point 12b connected to a connector 13b of the cylinder housing 7 of the engine 2.

[0045] Fig. 3B illustrates the ventilation device 1 integrated on the engine 2 by means of a connection point 12a connected to a connector 13a of the cylinder block 7 of the engine 2, and by means of a connection point 12c connected to a connector 13c of the cylinder head cover 8 of the engine 2.

[0046] Figure 4 illustrates another embodiment, in which the ventilation device 1 comprises five distribution members 6a, 6b, 6c, 6d, 6e, enabling, in particular, the motor 2 to be ventilated more quickly. The connection points 12 of the distribution members 6a, 6b, 6c, 6d, 6e are, for example, connected to connectors 13 located in risk areas of engine 2.

[0047] The ventilation device 1 illustrated in [Fig. 4] also includes a duct 14 located between the outside air inlet 3 and the outside air filtration means 4. This configuration allows, for example, the ventilation device 1 to adapt optimally to the arrangement of the engine 2 in the vehicle.

[0048] It is not excluded that the ventilation device 1 comprises several pipes and / or conduits and / or check valves, positioned according to different configurations to facilitate the integration of the ventilation device 1 onto the motor 2.

[0049] It should be noted that the ventilation device 1 which has just been described can advantageously be used to ventilate all types of internal combustion engine 2 of a motor vehicle.

Claims

Claims

1. Ventilation device (1) for an internal combustion engine (2) of a motor vehicle comprising at least one outside air inlet (3), means (4) for filtering the outside air, at least one common pipe (5) which communicates with the filtering means (4) and which is capable of distributing the filtered outside air in distribution members (6a, 6b, 6c) of the outside air towards the engine, characterized in that it comprises at least two distribution members (6a, 6b) which distribute outside air into a cylinder block (7) of the engine (2), and at least one distribution member (6c) which distributes outside air into a cylinder head cover (8) of the engine (2).

2. Ventilation device (1) of an engine (2) according to claim 1, wherein said distribution member (6a, 6b, 6c) comprises at least one outside air pipe (10) equipped with at least one non-return valve (H).

3. Ventilation device (1) of an engine (2) according to one of claims 1 and 2, in which said distribution member (6a, 6b, 6c) comprises at least one connection point (12) intended to be connected to a connector (13) of the engine (2).

4. Ventilation device (1) of an engine (2) according to claim 3, in which the two connection points (12a, 12b) of the two distribution members (6a, 6b) are connected to two connectors (13a, 13b) of the cylinder block (7) of the engine (2), these connectors (13a, 13b) being located at two opposite locations of the engine (2).

5. A ventilation device (1) for an engine (2) according to claim 4, wherein a connector (13a) of the cylinder block (7) is located on, or near, a distribution face of the engine, and a connector (13b) of the cylinder block (7) is located on, or near, a coupling face of the engine.

6. Ventilation device (1) of an engine (2) according to any one of claims 1 to 3, in which the connection point (12c) of the distribution member (6c) is connected to a connector (13c) of the cylinder head cover (8) of the engine (2).

7. Ventilation device (1) for an engine (2) according to any one of claims 1 to 6, in which the outside air inlet (3) makes it possible to inject fresh air inside the engine (2), and particularly into its isolated volumes, such as the cylinder block (7) and the cover cylinder head (8).

8. Ventilation device (1) according to claim 7, in which the outside air inlet (3) and the outside air filtration means (4) are separate from those of an air intake circuit of the engine (2) which allows the combustion chambers of the engine (2) to be filled with air.

9. Ventilation device (1) of an engine (2) according to any one of claims 1 to 8, said engine (2) being an internal combustion engine (2) of a motor vehicle running on hydrogen.

10. Engine (2) comprising a ventilation device (1) according to any one of claims 1 to 9.

11. A motor vehicle comprising an engine (2) according to claim 10 which comprises a ventilation device (1) according to any one of claims 1 to 7.

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