Fastening device for heat exchanger to cylinder head of internal combustion engine

Abstract

The present invention relates to a fastening device (1) for fastening a heat exchanger (3) to the cylinder head of an internal combustion engine, wherein the fastening device (1) comprises an opening (12) through which air from the heat exchanger (3) and directed toward an intake inlet located in the cylinder head can pass, and the fastening device (1) comprises at least one retaining region (14) and means for retaining liquid present in the retaining region (14).

Description

Technical Field

[0001] The present invention relates to the field of the automotive industry, and more particularly to a fastening device for a heat exchanger to a cylinder head of an internal combustion engine.

Background Art

[0002] In a vehicle equipped with a heat engine or an internal combustion engine, the engine has an intake port for injecting air into the combustion chamber of the engine. This port is located on the intake surface of the heat engine where a device for supplying outside air is mounted. On the opposite side of this intake surface of the engine, there is an exhaust surface to which a device of an exhaust line for conveying the burned gas to the outside of the engine and a pollution removal system is attached. These two surfaces extend longitudinally along the engine, that is, in the direction of its length.

[0003] In order to reduce pollutant emissions, the above heat engine is generally equipped with a line for recirculating the burned gas generated from the engine and the gas generated from the oil vapor. The burned gas is often redirected towards the intake port of the engine after being compressed upstream of the intake manifold and mixed with the outside air from outside the vehicle before being re-injected into the intake circuit of the engine.

[0004] The recirculated gas includes high-pressure gas directly taken in from the outlet of the exhaust surface of the engine or from an exhaust manifold attached to the engine, and low-pressure gas taken in further downstream at the height of a pollution removal device such as a catalytic converter or a nitrogen oxide trap.

[0005] To keep the air injected into the engine's intake circuit and the recirculated gases as cold as possible, a water-air heat exchanger is often used upstream of this intake circuit. This can improve engine efficiency. The heat exchanger is often positioned as close to the cylinder head as possible between the engine's throttle body and cylinder head, so that the air does not have time to heat up. Metal heat exchangers are often equipped with one or more plastic devices that allow the heat exchanger to be fastened to components located upstream and downstream of the heat exchanger. In particular, the first device is generally called the heat exchanger inlet box and is connected to the throttle body. The second device is generally called the cylinder head fastening box and allows the heat exchanger to communicate with the engine's cylinder head through the cylinder head plenum.

[0006] When a vehicle is parked, especially on a slope, a liquid retention area may form between the heat exchanger and the plenum of the engine's cylinder head, depending on the architecture of the powertrain, which includes a heat engine, and its configuration within the vehicle. Condensants may accumulate in this retention area, and these condensants may be oil condensates, refrigerant condensates, or water. The latter two types of condensates are problematic because, when they reach the engine pistons, if the cylinder block is located below the cylinder head, high concentrations of water can accumulate in the combustion chamber, damaging the engine.

[0007] To prevent such engine degradation, it is necessary to find a powertrain architecture that does not allow the formation of the aforementioned fluid retention region. However, such an architecture is difficult to achieve because it is not possible to guarantee a minimum parking gradient relative to the vehicle when the cylinder block is located below the cylinder head. [Overview of the Initiative]

[0008] The present invention aims to eliminate, at least to some extent, the drawbacks of the prior art by providing a fastening device for a heat exchanger to the cylinder head of an internal combustion engine, an internal combustion engine, a heat exchanger and a configuration comprising the fastening device, and an assembly comprising the heat exchanger, an air inlet box and the fastening device, which hold condensates and direct them toward a less problematic area than the engine's combustion chamber.

[0009] For this purpose, the present invention proposes a fastening device for a heat exchanger to the cylinder head of an internal combustion engine. The fastening device has an opening through which air from the heat exchanger, which is directed toward an intake inlet located in the cylinder head, can pass, and the fastening device comprises at least one retaining region and means for retaining a liquid present in the retaining region.

[0010] The fastening device according to the present invention, also known as a fastening box, thereby retains a liquid formed by condensation. The retaining means can freeze the condensation, especially in very cold climates, because the liquid condensed in the retaining area is retained there until at least a certain amount of liquid is held in that area. Furthermore, when the vehicle is restarted and assumes a position where the retaining area would be empty without the retaining means of the fastening device, the liquid is at least partially retained in the retaining area, thereby preventing deterioration of the engine of the vehicle connected to the fastening device.

[0011] The retaining means includes, for example, ribs protruding from the lower side wall of the opening. The fastening device is preferably made of molded plastic, and the ribs are molded, for example, at the same time as the fastening device according to the present invention.

[0012] The fastening device according to the present invention generally has the shape of a frame comprising four wall portions that define the opening of the fastening device, with air flowing into the opening through a first surface of the fastening device and flowing out of the opening through a second surface of the fastening device opposite the first surface. The first and second surfaces are substantially perpendicular to the four wall portions. "Substantially perpendicular" means perpendicularity of 30 degrees or less.

[0013] These first and second surfaces are arranged, for example, parallel to the main extending direction of the camshaft of an internal combustion engine. The first surface includes fastening means for a heat exchanger, such as a flange, which allows the tabs of the heat exchanger to cover and close this flange, and the second surface includes fastening means for a cylinder head, such as screw holes.

[0014] The lower wall of the opening is one of the four walls of the opening that are approximately parallel to the road surface when a vehicle is parked or driving on the road. "Approximately parallel" means that the lower wall is at zero or not zero but at an angle of less than 30 degrees to the road surface.

[0015] In a preferred embodiment, the fastening device according to the present invention comprises a passage for gases arising from oil vapor from a gas dispersion channel located in a cylinder head, the passage comprising at least one gas outlet hole formed in the lower side wall and a connection portion to the dispersion channel, the outlet hole being located outside the holding area.

[0016] This gas dispersion channel, which generates oil vapor located in the cylinder head, is also called a "blow-by" passage. Therefore, the passage located in the fastening device according to the present invention allows the gas generated from the oil vapor located in the cylinder head to flow out through the outlet hole, reach the opening of the fastening device, and be reinjected into the engine's intake inlet. The liquid contained in the retaining area is located outside the retaining area so that it does not flow directly into the passage for the gas generated from the oil vapor, and therefore into the dispersion channel located in the cylinder head. Otherwise, the engine oil would become contaminated with water or contaminants, which would be harmful to the engine.

[0017] The ribs extend, for example, from a first surface of the fastening device to a second surface of the fastening device, and the outlet hole is located between the ribs and the cylinder head. The passage is formed, for example, on the second surface at the lower part of the lower side wall, and the cylinder head closes the passage without blocking the outlet hole, and the dispersion channel opens into the passage when the cylinder head is fixed to the fastening device according to the present invention.

[0018] A preferred feature of the fastening device according to the present invention is that the rib comprises at least one drainage region for liquid overflowing from the retaining region. This makes it possible to control the discharge of excess liquid present in the retaining region, particularly by promoting its gradual evaporation. This drainage region also makes it possible to guide this excess liquid toward a less problematic area of ​​the fastening device or cylinder head than the engine intake.

[0019] In particular, the fastening device according to the present invention preferably includes a guide means capable of directing the liquid flowing out from the drainage area toward the outlet hole. Thus, the excess liquid is directed toward a passage for gases resulting from oil vapor, and therefore toward a dispersion channel leading to a decanter. This prevents condensate from reaching the combustion chamber of the engine.

[0020] In one embodiment of the present invention, the outlet hole is adjacent to a rib at the height of the drainage region, and the guide means forms the edge of the outlet hole.

[0021] According to an alternative embodiment, the guide means forms a channel that extends from the drainage area to the outlet hole.

[0022] The drainage region is formed, for example, by the lower region within the rib. For example, the rib has a first height of the drainage region and a second height greater than the first height over the remainder of its periphery. These heights are, of course, not zero. The first and second heights are optimized, for example, to allow maximum liquid retention when parked and liquid evaporation when driving. Alternatively, the drainage region is formed by holes in the rib.

[0023] Preferably, the fastening device comprises a plurality of outlet holes distributed along the rib, the rib comprises as many drainage areas as there are outlet holes, each outlet hole is adjacent to one of the drainage areas, and is bounded by guide means that can circulate the liquid flowing out of the drainage area up to the outlet hole. This distribution is regular in order to form a uniform distribution of oil from the "blow-by" cavity at the height of the intake plenum of the engine.

[0024] The fastening device according to the invention comprises, for example, two outlet holes that are symmetric with respect to the substantially rectangular symmetry plane, orthogonal to the lower wall part, and spaced apart by at least half of the maximum dimension of this substantially rectangular shape, with the rib defining a substantially rectangular shape.

[0025] The invention also relates to a configuration comprising an internal combustion engine, a heat exchanger, and a fastening device according to the invention that is sealingly connected on the one hand to the cylinder head of the internal combustion engine and on the other hand to the heat exchanger.

[0026] Finally, the invention relates to an assembly comprising a heat exchanger, an air inlet box that can be connected to the air inlet of the heat exchanger, and a fastening device according to the invention that can be connected to the air outlet of the heat exchanger.

Brief Description of the Drawings

[0027] [Figure 1] It is a perspective view of a configuration according to the invention comprising an internal combustion engine, a heat exchanger, and a fastening device according to the invention in one embodiment of the invention. [Figure 2] It is a side perspective view of an assembly according to the invention comprising a heat exchanger, an air inlet box connected to one face of the heat exchanger, and a fastening device according to the invention connected to the other face of the heat exchanger in this embodiment of the invention. [Figure 3] It is an upper perspective view of the assembly of FIG. 2. [Figure 4] It is a cross-sectional view of the fastening device of FIG. 2 with the cross-section parallel to one of the side walls of the fastening device. [Figure 5]Figure 2 shows one side view of a fastening device suitable for connection to the cylinder head of an internal combustion engine with the configuration shown in Figure 1. [Figure 6] This is a perspective view of the fastening device shown in Figure 2, which is the opposite side from the side shown in Figure 5. [Figure 7] Figure 5 is a magnified view of the surface area of ​​the fastening device shown. [Modes for carrying out the invention]

[0028] Other features and advantages of the present invention should become apparent, on the one hand, from the following description and on the other hand from several exemplary embodiments given for illustrative and non-limiting purposes with reference to the accompanying drawings.

[0029] According to one embodiment of the present invention shown in Figure 1, the configuration according to the present invention comprises an internal combustion engine shown in Figure 1, with only the cylinder head 2 being an internal combustion engine, a heat exchanger 3, and a fastening device 1 according to the present invention, which is sealed and connected on one side to the air outlet of the heat exchanger 3 and on the other side to the intake surface located in the cylinder head 2 of the internal combustion engine. The intake surface opens to the intake inlet in the cylinder head 2, thereby enabling air to be transported to the combustion chamber of the engine. This surface extends substantially parallel to the longitudinal direction Y, which is itself parallel to the rotation axis of the engine's camshaft, and substantially parallel to the vertical direction Z, which is perpendicular to the longitudinal direction Y and the transverse direction X. The transverse direction X extends perpendicular to the vertical direction Z and the longitudinal direction Y and is substantially parallel to the direction of the airflow passing through the intake surface of the cylinder head 2.

[0030] The air that is sent through the heat exchanger 3 and subsequently through the fastening device 1 to reach the intake inlet of the cylinder head 2 flows in through an intake conduit 7 connected by a connection part 6 to a throttle body 5 equipped with a throttle valve controlled by a control unit. The throttle valve can modulate the air pressure at the inlet of the air inlet box 4 to which the valve is connected, and this air inlet box 4 makes it possible to direct the air flowing out of the throttle valve towards the air inlet of the heat exchanger 3.

[0031] Therefore, the air inlet box 4 has an air outlet surface connected to the air inlet of the heat exchanger 3, and the air outlet surface has an air outlet connected to the first air inlet surface 30 of the fastening device 1 (see in particular Figure 4) and the second air outlet surface 32 of the fastening device 1 (see similarly Figure 4) connected to the intake surface of the cylinder head 2. All of these surfaces are substantially parallel to each other and therefore substantially parallel to the longitudinal direction Y and the vertical direction Z.

[0032] As shown in Figure 2, the fastening device 1 has a frame shape with four walls that define the opening 12 of the fastening device 1, and air flows into the opening 12 through the first surface 30 of the fastening device 1 and out through the second surface 32 of the fastening device 1 opposite the first surface 30. The first and second surfaces 30 and 32 are substantially perpendicular to the four walls.

[0033] In this embodiment of the present invention, the heat exchanger 3 is made of metal, for example, aluminum, and is connected to the flange of the fastening device 1 by a bent metal tab, the flange of which borders the first air inlet surface 30 of the fastening device 1. The heat exchanger 3 is also connected to the flange of the air inlet box 4 by a bent metal tab.

[0034] The fastening device 1 includes a lower wall portion 16 substantially parallel to the longitudinal direction Y and the transverse direction X. This lower wall portion 16 may include a retaining area 14 for oil or water condensation, depending on the inclination of the vehicle, especially when the vehicle is parked on a slope.

[0035] To prevent these fluids from being directly injected into the engine's intake when the vehicle is restarted and assumes a less inclined position than when parked, the fastening device 1 according to the present invention includes means for holding these fluids in a holding area 14, which in this embodiment of the present invention are ribs 18 shown in Figure 3. In this embodiment, the fastening device 1 is made of a molded synthetic material, and the ribs 18 are formed by molding.

[0036] The rib 18 defines a retaining region 14 extending downward from the heat exchanger 3 to retain moisture in the air at the outlet of the heat exchanger 3, as this moisture condenses and flows onto the lower wall portion 16. Thus, the rib 18 comprises two arms 181, 182 substantially parallel to the transverse direction X, and therefore substantially parallel to the direction of airflow. Each of these arms 181, 182 is connected at one end by a branch 183 substantially parallel to the longitudinal direction Y, the branch 183 being closer to the second surface 32 of the device compared to the other end of these arms 181, 182. Each of these other ends is located at a separate end of the intersection between the lower wall portion 16 and the air outlet surface of the heat exchanger 3, and / or between the lower wall portion 16 and the portion of the lower wall portion 16 with a change in height.

[0037] In fact, as shown in Figure 4, the lower wall portion 16 has a receiving surface 162 that is inclined with respect to the remainder 164 of the lower wall portion 16 and is located near the first surface 30 for the heat exchanger 3. Thus, the arms 181 and 182 of the rib 18 start outside this receiving surface 162, and the remainder 164 of the lower wall portion 16 is located between the two arms 181 and 182 and the branch 183 of the rib 18, which form a holding region 14 outside the heat exchanger 3.

[0038] As can be seen in particular from Figure 5, the fastening device 1 is formed as a recess in its second surface 32 and is positioned in the cylinder head 2, and includes a passage 20 for gases generated from oil vapor from a gas dispersion channel that opens therethrough through a dedicated opening 8. This passage 20 is bounded by the edge 31 of the lower wall portion 16 extending over the second surface 32, further by a flange extending over the second surface 32 and receiving a sealing gasket 26, and further by outlet holes 22, 24 positioned on the second surface 32. These outlet holes 22, 24 allow gases generated from oil vapor from the engine's cylinder head 2 to flow out into the opening 12 of the fastening device 1.

[0039] Therefore, the intake surface of the cylinder head 2 is fastened to the second surface 32 of the fastening device 1 by screws passing through screw passages 28 arranged particularly around the periphery of the second surface 32, and the cylinder head 2 closes the passage 20, while still allowing gases from oil vapors flowing out of the cylinder head 2 through the dedicated opening 8 to circulate through the passage 20. The gases from the oil vapors can then reach the opening 12 of the fastening device 1 through the outlet holes 22, 24 and flow into the engine's plenum. The sealing gasket 26 prevents any leakage of air or gases from the oil vapors to the outside of the fastening device 1 or the cylinder head 2.

[0040] The outlet holes 22 and 24 are located within the lower wall portion 16 but outside the retaining region 14. Therefore, the condensate held in the retaining region 14 by the rib 18 cannot flow directly into the so-called "blow-by" cavity of the cylinder head.

[0041] On the other hand, the rib 18 includes drainage areas 34 (see Figures 4 and 6 in particular) for liquid overflowing from the holding area 14. These drainage areas 34 allow excess liquid to be discharged gradually and without flowing into the intake conduit of the cylinder head 2. In particular, the drainage areas 34 are located near the outlet holes 22 and 24, allowing excess liquid to fall into the passage 20, thereby preventing it from flowing into the combustion chamber of the engine.

[0042] As shown in Figure 6, these drainage regions 34 are formed in each drainage region 34 by a rib height h1 that is lower than the height h2 of the rib outside the drainage region 34.

[0043] Figure 7 shows an enlarged view of the second surface 32 at the height of the outlet hole 22 to clarify the configuration of the drainage region 34 and the outlet holes 22, 24, respectively. The outlet hole 22 is adjacent to the rib 18 at the height of the drainage region 34. Guide means, configured by the edges 36 on each surface of the outlet hole 22 in this embodiment, guide excess liquid that passes over the rib 18 in the drainage region toward the outlet hole 22.

[0044] The drainage region 34 is bounded by a portion of the rib 18 having a height h1 that is lower than the height h2, so that each of the edges 36 extends transversely X from a separate end of the portion of the rib that borders the drainage region 34 to a second surface 32, i.e., a surface for contacting the cylinder head 2.

[0045] The outlet holes 22, 24 and associated drainage areas 34 are symmetrical with respect to the plane of symmetry of the ribs 18 extending in the transverse X and vertical Z directions, and are regularly distributed along the ribs 18. The outlet holes 22, 24 are spaced apart from each other, in particular, to uniformly disperse gases resulting from oil vapor flowing into the engine plenum.

[0046] Naturally, the present invention is not limited to the examples described herein, and numerous modifications can be made to these examples without departing from the scope of the invention. In particular, three or more outlet holes or just one outlet hole may be arranged, for example, in the lower wall portion 16. Furthermore, in alternative embodiments of the present invention, the outlet holes 22, 24 are offset with respect to the drainage region 34, and the guide means become ribs that form an actual conduit between the drainage region 34 and the outlet holes 22, 24. The term “offset” is understood to mean the positioning of the drainage region 34 substantially aligned with the outlet holes 22, 24, particularly above the outlet holes 22, 24, such that the drainage region is connected to the outlet holes by a conduit formed by the guide means (edge) 36.

Claims

1. A fastening device (1) for a heat exchanger (3) to a cylinder head (2) of an internal combustion engine, wherein the fastening device (1) has an opening (12) through which air from the heat exchanger (3) and directed toward an intake inlet located in the cylinder head (2) can pass, A fastening device (1) comprising at least one retaining region (14) and a retaining means for a liquid present in the retaining region (14).

2. The fastening device (1) according to claim 1, wherein the retaining means comprises a rib (18) protruding from the lower side wall portion (16) of the opening (12).

3. The fastening device (1) according to claim 1 or 2, comprising a passage (20) for gas generated from oil vapor from a gas dispersion channel located in the cylinder head (2), the passage (20) comprising at least one gas outlet hole (22, 24) formed in the lower side wall portion (16) and a connection portion to the dispersion channel, wherein the outlet hole (22, 24) is located outside the retaining region (14).

4. The fastening device (1) according to claim 3, wherein the rib (18) comprises at least one drainage area (34) for liquid overflowing from the holding area (14).

5. The fastening device (1) according to claim 4, wherein the rib (18) has a first height (h1) of the height of the drainage region (34) and a second height (h2) that is higher than the first height (h1) and extends to the remaining portion of its periphery.

6. The fastening device (1) according to claim 4 or 5, further comprising a guide means (36) capable of directing the liquid flowing out of the drainage area (34) toward the outlet holes (22, 24).

7. The fastening device (1) according to claim 6, wherein the guide means (36) forms a channel extending from the drainage region (34) to the outlet holes (22, 24).

8. The fastening device (1) according to claim 6, wherein the outlet holes (22, 24) are adjacent to the rib (18) at the height of the drainage region (34), and the guide means (36) forms the edge of the outlet holes (22, 24).

9. The fastening device (1) according to any one of claims 6 to 8, comprising a plurality of outlet holes (22, 24) dispersed along the rib (18), the rib (18) comprising the same number of drainage regions (34) as the outlet holes (22, 24), each outlet hole (22, 24) adjacent to one of the drainage regions (34), and bounded by the guide means (36) that allows the liquid flowing out of the drainage region (34) to flow to the outlet holes (22, 24).

10. The configuration comprises an internal combustion engine, the heat exchanger (3), and a fastening device (1) according to any one of claims 1 to 9, which is sealed and connected on one side to the cylinder head (2) of the internal combustion engine and on the other side to the heat exchanger (3).

11. An assembly comprising: a heat exchanger (3); an air inlet box (4) connectable to the air inlet of the heat exchanger (3); and a fastening device (1) according to any one of claims 1 to 9 connectable to the air outlet of the heat exchanger (3).

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