Air intake arrangement for an internal combustion engine

Abstract

The invention relates to an air intake arrangement for an internal combustion engine (2), wherein the air intake arrangement (1) comprises an elongated airbox (4) extending along a longitudinal axis (3) with an airbox interior (6) formed by an airbox inner wall (5), a fresh air inlet (8) communicating with the airbox interior (6) and an intake funnel arrangement (9) with several intake funnels (10) in the airbox interior (6), wherein the inner wall (5) of the airbox has a connection section (17) with at least one opening for the funnel outlets (14) and a covering section (18). It is proposed that the covering section (18) has a curved section (19) which is curved outwards transversely to the longitudinal axis (3), and that for each intake funnel (10) the inflow direction into the funnel inlet (13) is at an obtuse deflection angle (20) to the outflow direction from the funnel outlet (14), and the arrangement is such that the intake funnels (10) each open with their funnel inlet (13) towards the curved section (19).

Description

[0001] The present invention relates to an air intake arrangement for an internal combustion engine according to the preamble of claim 1 and to a motor vehicle with an air intake arrangement according to claim 11.

[0002] Air intake assemblies for internal combustion engines in motor vehicles serve to provide clean, low-temperature and, above all, sufficient air in order to increase the combustion efficiency and performance of the internal combustion engine.

[0003] For carburetor engines, which are often found in older vehicles, the air intake layout plays a special role. This is especially true in historic motorsport, where maximum power output is essential for often low-displacement combustion engines. Such vehicles are usually equipped with multiple carburetors or a set of dual carburetors, depending on the number of cylinders.

[0004] The air intake assembly is now tasked with supplying the individual carburetors with fresh air. The primary goal is to distribute the fresh air to the carburetors as evenly and laminarly as possible. For this purpose, the air intake assembly features a so-called airbox, which has a fresh air inlet communicating with the airbox interior and directs the fresh air flow to the combustion engine in a predetermined manner.

[0005] The known prior art (EP 3 752 730 B1), from which the invention is based, relates to an air intake arrangement for an internal combustion engine of a motor vehicle with an airbox and intake funnels arranged therein for guiding fresh air. The incoming fresh air flow first passes through an air filter and is then divided into partial flows for each intake funnel by corresponding partition walls in the airbox and redirected such that each partial flow flows perpendicularly towards the associated funnel inlet. This known air intake arrangement forces the fresh air flow to be divided into individual, comparatively narrow channels, each assigned to an intake funnel. On the one hand, such an arrangement is associated with high flow resistance, which counteracts the optimal supply of fresh air to the internal combustion engine.

[0006] In addition, the limitations of the engine compartment of motor vehicles pose a particular challenge. Due in particular to the integration of the wheel arches into the body, the distance between the combustion engine and the side wall of the vehicle body is very small. Accordingly, there is little space available for the air intake assembly in the engine compartment. The conventional air intake assembly is unsuitable for such a placement due to its protruding shape, as a slim implementation appears impossible.

[0007] The invention is based on the problem of designing and developing the known air intake arrangement in such a way that an optimal supply of fresh air to the combustion engine is achieved while at the same time being slim in design.

[0008] The above problem is solved by the features of the characterising part of claim 1.

[0009] The fundamental idea is to bulge an elongated airbox, at least in sections, transversely to its longitudinal extension, and to design and arrange the funnel arrangement by equipping it with an obtuse deflection angle so that the intake funnels each open towards the bulge. It has been recognized that by equipping the airbox inner wall with a bulged section, the fresh air flow can be adjusted over a wide range without having to deviate from a slim overall design. Flow effects such as the well-known Coanda effect can be utilized, further increasing the compactness of the arrangement.

[0010] According to the proposal, it is initially assumed that the air intake arrangement has an elongated airbox extending along a longitudinal axis, with an airbox interior formed by an airbox inner wall and a fresh air inlet communicating with the airbox interior, and an intake funnel arrangement with a plurality of intake funnels in the airbox interior. The intake funnels each have a flow channel from a funnel inlet to a funnel outlet, wherein the intake funnels each lead from the funnel inlet in the airbox interior via the flow channel to the funnel outlet out of the airbox interior. The air intake arrangement can be connected to an intake system of the internal combustion engine via the funnel outlets, so that the internal combustion engine can be supplied with fresh air via the fresh air inlet and the intake funnel arrangement.The airbox inner wall has a connecting section with at least one opening for the funnel outlets and an enveloping section, wherein the funnel inlets are located between the connecting section and the enveloping section when viewed in a longitudinal section.

[0011] In detail, it is proposed that the envelope section has a curved section which is curved outwards transversely to the longitudinal axis, and that for each intake funnel the inflow direction into the funnel inlet is at an obtuse deflection angle to the outflow direction from the funnel outlet and the arrangement is such that the intake funnels each open with their funnel inlet towards the curved section.

[0012] The preferred embodiment according to claim 2 is particularly well suited for longitudinally mounted inline combustion engines, in which the cylinders are arranged in one or two rows. The air intake assembly is then arranged next to the combustion engine, i.e., between the combustion engine and the side wall of the vehicle body. The slim design of the proposed solution is particularly advantageous here.

[0013] The obtuse deflection angle must be sufficiently large so as not to unduly slow down the fresh air flow. Claim 3 specifies advantageous angle ranges for this purpose.

[0014] At the same time, the obtuse deflection angle must not be too large to ensure that the intake funnels can open toward the curved section within the available installation space. This is the subject of claim 4.

[0015] The design according to claim 5 results in an overall curved shape, which basically supports the creation of a laminar fresh air flow.

[0016] According to claim 6, the intake funnels preferably have a clear inlet cross-sectional area and a clear outlet cross-sectional area inclined thereto, which defines the deflection angle in a structurally simple variant. The cross-sectional areas are preferably rounded and, in particular, circular.

[0017] The curved course of the flow channel according to claim 7 further supports a laminar fresh air flow and thus optimizes the supply of fresh air to the combustion engine.

[0018] In the further preferred embodiment according to claim 8, the fresh air flow is divided into a primary flow extending along the envelope section and a secondary flow extending along the connecting section. This allows the entire airbox interior to be utilized for guiding the fresh air flow, allowing a maximum volume flow for the fresh air flow to be generated.

[0019] The straight course of the connecting section according to claim 9 simplifies the design of an engine-side flange which can be attached to the internal combustion engine, in particular to the carburettor of the internal combustion engine.

[0020] It was indicated above that the proposed solution makes it possible to utilize the Coanda effect to guide the fresh air flow, in this case the primary flow. This is a particularly space-saving method for distributing the fresh air flow evenly across all cylinders of the combustion engine. This is the subject of claim 10.

[0021] According to a further teaching according to claim 11, which has independent significance, a motor vehicle with an air intake arrangement according to one of the preceding claims is claimed. Reference is made to all statements regarding the proposed air intake arrangement.

[0022] In the particularly preferred embodiment according to claim 12, the longitudinal axis of the air intake arrangement is aligned substantially parallel to the direction of travel of the motor vehicle, which can be particularly advantageous with regard to the inflow of fresh air.

[0023] In the following, the invention is explained in more detail with reference to a drawing which merely represents exemplary embodiments. In the drawing, Fig. 1 a view into the opened engine compartment with a proposed air intake arrangement mounted therein, Fig. 2 a longitudinal section through the air intake arrangement according to Fig. 1 and Fig. 3 a cross section through the air intake arrangement.according Fig. 1.

[0024] The exemplary embodiment shown in the figures and preferred in this respect relates to an air intake arrangement 1 for an internal combustion engine 2, wherein the air intake arrangement 1 has an elongated airbox 4 extending along a longitudinal axis 3 with an airbox interior 6 formed by an airbox inner wall 5. Fig. 1 shows that the elongated, slim design of the airbox 4 enables it to be arranged between the combustion engine 2 and a side wall 7 of the vehicle body.

[0025] The air intake assembly 1 has a fresh air inlet 8 communicating with the airbox interior 6 and, in the airbox interior 6, an intake funnel assembly 9 with a plurality of intake funnels 10. The fresh air inlet 8 preferably opens toward the front of the vehicle, so that, when installed, it is exposed to the airflow of the motor vehicle.

[0026] The fresh air inlet 8 can be equipped with an air filter 11 such that all fresh air flowing into the airbox interior 6 flows through the air filter 11. The air filter 11 can be designed, for example, as a paper, foam, or fabric filter. In a particularly preferred embodiment, it can be inserted into the fresh air inlet 8 with a positive and / or non-positive fit.

[0027] The intake funnel arrangement 9 is arranged at least partially, here and preferably completely, in the airbox interior 6. The intake funnel arrangement 9 is attached entirely to the airbox 4. A preferred embodiment of the intake funnel arrangement 9 can be seen in the illustrations according to Fig. 2 and Fig. 3.

[0028] Each intake funnel 10 is equipped with a flow channel 12 from a funnel inlet 13 to a funnel outlet 14, wherein the intake funnels 10 each lead from the funnel inlet 13 in the airbox interior 6 via the flow channel 12 to the funnel outlet 14 out of the airbox interior 6.

[0029] The air intake arrangement 1 can be connected via the funnel outlets 14 to an intake system 15 of the internal combustion engine, in particular to a carburettor arrangement 16, so that the internal combustion engine can be supplied with fresh air via the fresh air inlet 8 and the intake funnel arrangement 9.

[0030] The airbox inner wall 5 has a connecting section 17 with at least one opening for the funnel outlets 14 and an enveloping section 18, wherein, viewed in a longitudinal section, the funnel inlets 13 are located between the connecting section 17 and the enveloping section 18. This can be seen from the illustration according to Fig. 2.

[0031] It is now essential that the envelope section 18 has a curved section 19 which is curved outwards transversely to the longitudinal axis 3, and that for each intake funnel 10 the inflow direction into the funnel inlet 13 is at an obtuse deflection angle 20 to the outflow direction from the funnel outlet 14 and the arrangement is such that the intake funnels 10 each open with their funnel inlet 13 towards the curved section 19.

[0032] In the assembled state, the outflow direction from the respective funnel outlet 14 is preferably aligned horizontally and / or the inflow direction into the respective funnel inlet 13 is preferably aligned obliquely upwards. The intake funnels 10 are further preferably aligned with one another such that the inflow directions and / or the outflow directions of the individual intake funnels 10 are aligned substantially parallel to one another.

[0033] Furthermore, it is preferably provided here that the intake funnels 10 are arranged one behind the other along the longitudinal axis 3, and / or that the flow channels 12 of the intake funnels 10 are each aligned at least in part substantially transversely to the longitudinal axis 3.

[0034] Fig. Figure 3 shows that here, and preferably, the obtuse deflection angle 20 is at least 110° and more preferably at least 115°. This illustration shows that, in the assembled state, such a flat configuration of the intake funnels 10 can lead to a space-optimized arrangement.

[0035] However, the profile of the intake funnels 10 must not be too flat in the assembled state, as otherwise the side wall 7 of the vehicle body may be obstructive. Accordingly, it is preferably provided here that the obtuse deflection angle 20 is less than 170°, more preferably that the obtuse deflection angle 20 is less than 150°, and more preferably that the obtuse deflection angle 20 is less than 130°.

[0036] A summary of the Fig. 2 and Fig. 3 shows that here and preferably the curved section 19 is curved outward relative to the longitudinal axis 3, both in longitudinal section and in cross-section transverse to the longitudinal axis 3. This curvature in two degrees of freedom results in an overall rounded shape of the airbox 4, which supports the generation of a laminar fresh air flow. The curved section 19 extends, viewed in cross-section transverse to the longitudinal axis 3, over an angular range of more than 90°, preferably more than 120°, more preferably more than 160°.

[0037] The funnel inlet 13 and / or the funnel outlet 14 for each intake funnel 10 are preferably oriented transversely to the inflow direction or the outflow direction, respectively. This can support the generation of a laminar flow even within the respective intake funnel 10. In this context, it is preferably provided that for each intake funnel 10, the funnel inlet 13 has a clear inlet cross-sectional area 21 that is inclined relative to the clear outlet cross-sectional area 22, in particular inclined by the deflection angle 20.

[0038] A settling chamber 23 extends above the inlet cross-sectional area 21, which, viewed in cross-section, is bounded transversely to the longitudinal axis 3 by a straight line extending through the inlet cross-sectional area 21 on the one hand and the curved section 19 on the other. The height of the settling chamber 23, defined as the maximum orthogonal distance between the inlet cross-sectional area 21 and the curved section 19, here and preferably corresponds at least to the width of the inlet cross-sectional area 21 viewed in cross-section transversely to the longitudinal axis 3.

[0039] Furthermore, it is preferably provided here that the flow channel 12 is curved in such a way that the obtuse deflection angle 20 is established. In principle, a discontinuous course of the flow channel 12 is also conceivable, which, although contrary to a laminar flow within the intake funnels 10, can be advantageous from a manufacturing point of view.

[0040] Furthermore, it is preferably provided here that the connecting section 17 and the enveloping section 18 are designed and arranged such that the fresh air flow flowing in via the fresh air inlet 8 is divided into a primary flow 24, which extends along the enveloping section 18, and a secondary flow 25, which extends along the connecting section 17. This division of the fresh air flow can best be illustrated in accordance with Fig. 2. This shows that the airbox interior 6 is optimally utilized by the fresh air flow.

[0041] Furthermore, it is preferably provided here that the connecting section 17 runs essentially straight when viewed in a longitudinal section. "Straight" in this case means that the connecting section 17 extends at least partially along a plane. This plane is preferably a flange plane 26 in which the outlet cross-sectional areas 22 of the intake funnels 10 for connection to the carburetor assembly 16 are located.

[0042] Furthermore, it is preferably provided here that the curved section 19 is shaped such that the primary flow 24 is deflected transversely to the longitudinal axis 3 by the Coanda effect in order to follow the envelope section 18. Thus, the fresh air flow is initially guided away from the intake funnels 10 transversely to the longitudinal axis 3, so that the rear intake funnels 10 can be better supplied with fresh air. The Coanda effect generally describes the tendency of a gas or fluid flow to "run along" (snuggle up) a curved surface instead of detaching and continuing in the original flow direction. This use of the Coanda effect enables a particularly elegant guidance of the fresh air flow while simultaneously supporting laminar flow.

[0043] An optimal course of the fresh air flow can be supported by a preferred width to length ratio of the airbox 4 along the intake funnel arrangement 9. Preferably, in the assembled state, the ratio of the horizontal width of the airbox 4 in the region of the intake funnel arrangement 9 to the length of the airbox 4 along the intake funnel arrangement 9, which corresponds to the length of the intake funnel arrangement 9 along the longitudinal axis 3, is more than 10:30, preferably more than 12:30.

[0044] According to a further teaching of independent significance, a motor vehicle with a proposed air intake arrangement 1 is claimed as such. Reference may be made to all statements regarding the proposed air intake arrangement 1.

[0045] Preferably, the motor vehicle is assigned a direction of travel 27 that is aligned substantially parallel to the longitudinal axis 3 of the air intake assembly 1. This ensures optimal flow to the fresh air inlet 8. The air intake assembly 1 is preferably arranged between the internal combustion engine 2 and the side wall 7 and is aligned with its longitudinal axis 3 along the direction of travel 27 of the motor vehicle.

[0046] The airbox 4 can be made at least partially from a weight-saving plastic material, in particular a fiber-reinforced plastic material. In principle, the airbox 4 can be designed as a single piece and consist of such a plastic material. Alternatively, and as shown in the drawing, the connecting section 17 is otherwise designed separately from the airbox 4. Here and preferably, the connecting section 17, which simultaneously forms a flange 28 for the carburetor arrangement 16, is made of a metal material and / or a plastic material. The intake funnel arrangement 9 can in principle be made of a metal material. In a particularly preferred embodiment, the intake funnel arrangement 9 is likewise made of a weight-saving plastic material. List of reference symbols 1 air intake arrangement 2 combustion engine 3 Longitudinal axis 4 Airbox 5 Airbox inner wall 6 Airbox interior 7 Side wall 8 Fresh air intake 9 Intake funnel arrangement 10 intake funnels 11 Air filter 12 flow channel 13 Funnel inlet 14 Funnel outlet 15 Intake system 16 Carburettor arrangement 17 connecting section 18 Envelope section 19 vault section 20 deflection angles 21 Inlet cross-sectional area 22 Outlet cross-sectional area 23 Calming room 24 Primary current 25 Secondary current 26 Flange level 27 Direction of travel 28 flange QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 752 730 B1

[0005]

Claims

[1] Air intake arrangement for an internal combustion engine (2), wherein the air intake arrangement (1) has an elongated airbox (4) extending along a longitudinal axis (3) with an airbox interior (6) formed by an airbox inner wall (5), a fresh air inlet (8) communicating with the airbox interior (6) and, in the airbox interior (6), an intake funnel arrangement (9) with a plurality of intake funnels (10), wherein the intake funnels (10) each have a flow channel (12) from a funnel inlet (13) to a funnel outlet (14), wherein the intake funnels (10) each lead from the funnel inlet (13) in the airbox interior (6) via the flow channel (12) to the funnel outlet (14) out of the airbox interior (6), wherein the air intake arrangement (1) can be connected to an intake system (15) of the internal combustion engine (2) via the funnel outlets (14), so that the internal combustion engine (2) can be supplied with fresh air via the fresh air inlet (8) and the intake funnel arrangement (9), wherein the airbox inner wall (5) has a connecting section (17) with at least one opening for the funnel outlets (14) and an enveloping section (18), wherein, viewed in a longitudinal section, the funnel inlets (13) are located between the connecting section (17) and the enveloping section (18), characterized by , that the envelope section (18) has a curved section (19) which is curved outwards transversely to the longitudinal axis (3), and that for each intake funnel (10) the inflow direction into the funnel inlet (13) is at an obtuse deflection angle (20) to the outflow direction from the funnel outlet (14) and the arrangement is such that the intake funnels (10) each open with their funnel inlet (13) towards the curved section (19). [2] Air intake arrangement according to claim 1, characterized by that the intake funnels (10) are arranged one behind the other along the longitudinal axis (3), and / or that the flow channels (12) of the intake funnels (10) are each aligned at least partly substantially transversely to the longitudinal axis (3). [3] Air intake arrangement according to claim 1 or 2, characterized by that the obtuse deflection angle (20) is at least 110°, preferably that the obtuse deflection angle (20) is at least 115°. [4] Air intake arrangement according to claim 3, characterized by that the obtuse deflection angle (20) is less than 170°, preferably that the obtuse deflection angle (20) is less than 150°, further preferably that the obtuse deflection angle (20) is less than 130°. [5] Air intake arrangement according to one of the preceding claims, characterized by that the arched section (19) is arched outwards relative to the longitudinal axis (3) both in longitudinal section and in cross-section transverse to the longitudinal axis (3). [6] Air intake arrangement according to one of the preceding claims, characterized by that for each intake funnel (10) the funnel inlet (13) has a clear inlet cross-sectional area (21) which is inclined relative to the clear outlet cross-sectional area (22), in particular inclined by the deflection angle (20). [7] Air intake arrangement according to one of the preceding claims, characterized bythat the flow channel (12) is curved in such a way that the obtuse deflection angle (20) is established. [8] Air intake arrangement according to one of the preceding claims, characterized by that the connecting section (17) and the enveloping section (18) are designed and arranged such that the fresh air flow flowing in via the fresh air inlet (8) is divided into a primary flow (24) which extends along the enveloping section (18) and a secondary flow (25) which extends along the connecting section (17). [9] Air intake arrangement according to one of the preceding claims, characterized by that, viewed in a longitudinal section, the connecting section (17) is substantially straight. [10] Air intake arrangement according to one of the preceding claims, characterized bythat the arched section (19) is shaped such that the primary flow (24) is deflected by the Coanda effect transversely to the longitudinal axis (3) in order to follow the envelope section (18). [11] Motor vehicle with an air intake arrangement (1) according to one of the preceding claims. [12] Motor vehicle according to claim 11, characterized by that the motor vehicle is assigned a direction of travel (27) and that the longitudinal axis (3) of the air intake arrangement (1) is aligned substantially parallel to the direction of travel (27).

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