EP2584186A1 - Air intake device - Google Patents

Abstract

The device (10) has a filter housing (12), and a suction channel arrangement (14) provided for sucking air from an outer area (A) into the housing. A flow path (S1) and another flow path are arranged in the arrangement, and a valve device (16) is adjusted between two positions. The valve device influences flow of the air into the arrangement, where the arrangement has a suction opening (21). The valve device is designed such that a flow cross-section (Q1) of the former flow path is locally reduced during a portion of an adjusting movement of the valve device from one of the positions.

Description

The present invention relates to an air intake device for a motor vehicle, which comprises a filter housing and an intake duct arrangement opening into the filter housing for drawing in air from an outer area into the filter housing, wherein a first flow path and at least one second flow path different from the first flow path are provided in the intake duct arrangement and, which comprises at least one of a first and a second position adjustable valve means for influencing a flow of sucked air in the Ansaugkanalanordnung, wherein the valve means is adapted, at least during a portion of an adjustment movement of the valve means from the second position out a flow cross-section of the second Reduce flow paths locally.

By such an air intake unfiltered air is sucked from an outside area via the intake passage in the filter housing, filtered and can be supplied from there via suitable lines to the combustion chambers of an internal combustion engine of the motor vehicle.

Due to the rhythmic opening and closing movements of the valves in the combustion chambers, there may be pressure fluctuations during operation in the air column present in the air intake device and thus not inconsiderable noise development. By adjusting the valve device, the flow conditions in the Ansaugkanalanordnung and thus in particular the sound transmission properties of the air intake can be influenced, such as to provide a sound-absorbing effect in a certain frequency range. The filter housing and the respective flow path can form a Helmholtz resonator. By switching between the first and second flow paths For example, the frequency range in which the intake duct arrangement acts as a Helmholtz resonator can be changed within the scope of the existing duct geometry.

Such an air intake device is for example from the document WO 99/47807 A1 known. In the air intake device operated in this document, the intake duct arrangement is formed by two separate intake ducts opening into the filter housing at different locations, the intake air being in the first position of the valve device along the first flow path only through one of the intake ducts and in the second position along a second flow path is passed simultaneously through both intake pipes. In this known air intake device, the flow cross section along the first flow path is independent of the position of the valve device, which limits the possibility of influencing the sound transmission properties of the air intake device by adjusting the valve device.

Against the background of this prior art, the object of the present invention is to provide an air intake device whose sound transmission characteristics are adjustable in a more flexible manner than is known in the art.

This object is achieved in that in a generic air intake device, the valve device is further adapted to locally reduce at least during a portion of an adjustment of the valve device from the first position out a flow cross-section of the first flow path.

According to the invention, therefore, both the flow cross section of the first and the flow cross section of the second flow path can be varied, which compared to the prior art, a larger scope of specifically adjustable different flow conditions and thus in particular the sound transmission properties of the air intake allows.

In principle, it should not be ruled out, for example, to provide a separate valve in each flow path, wherein the valves can be set independently within the scope of the most general solution of the above-mentioned object, as long as only the above conditions for changing the local flow cross sections of the individual flow paths are complied with. The term "position of the valve device" then refers to a combination of the positions of the individual valves.

Preferably, however, it is provided that the valve device is designed at the same time, at least during a portion of an adjustment movement of the valve device from the first position to the second position, the flow cross-section of the second flow path locally, i. at least at one point along the second flow path, to increase and locally reduce the flow cross-section of the first flow path, which opens the possibility to realize the adjustment via exactly one valve, so that the structure of the air intake can be simplified. This is also ensured with a larger scope of different adjustable flow conditions that the connected to the air intake engine is always supplied with fresh gas regardless of the current position of the valve device.

Also referred to in the preceding paragraph advantageous opposite effect of an adjustment of the valve device, wherein a local flow cross-section of a flow path decreasing adjustment of the valve device simultaneously leads to an increase in the local flow cross section of each other flow path can with a plurality of valves, about at least one per Flow path, having valve device be realized, although this is not preferred due to the associated increase in the number of components and the control effort.

According to a preferred embodiment of the present invention, it is provided that in the first position of the valve device sucked by the Ansaugkanalanordnung air predominantly or substantially completely passes on the first flow path in the filter housing and / or in the second position of the valve means the air sucked through the Ansaugkanalanordnung predominantly or substantially completely passes on the second flow path in the filter housing.

By adjusting the valve device so different flow paths can be selected via which the air sucked into the filter housing, so that the air flow and the sound transmission properties of the air intake in function of operating parameters of the motor vehicle, such as an engine speed, a desired or measured sound level or the like while ensuring the supply of fresh gas to the internal combustion engine can be adjusted by selecting a suitable flow path.

To simplify the assembly, it is preferred that the intake duct arrangement is a single, preferably one-piece component.

In particular, it can be provided that the first and the second flow path open into one another with respect to a suction flow along the first flow path upstream of the filter housing at an orifice. With such an air intake device, it is possible to connect the intake passage assembly at a single connection point with the filter housing at which the intake passage arrangement opens into the filter housing, which can simplify the assembly of the device.

Unless otherwise indicated, terms such as downstream and upstream in the present text always refer to a suction flow along the first flow path.

It can be provided that the valve device comprises a valve which is provided upstream of the discharge point in or on the Ansaugkanalanordnung. Such a valve, which may for example be a simple flap valve, narrows or closes in the first position the flow cross section of the second flow path at the discharge point and narrows or closes in the second position the flow cross section of the first flow path upstream of the discharge point ,

Alternatively or additionally, the intake duct arrangement may have a single intake opening, wherein the second flow path branches off from the first flow path downstream of the intake opening in a branch point. This is particularly advantageous, if desired, to suck air always independent of the position of the valve device from the same area.

It can be provided that the valve device comprises a valve which is provided downstream of the branch point in or on the Ansaugkanalanordnung and which narrows or closes the flow cross section of the second flow path, for example at the branch point in the first position and the first in the second position Narrows or closes flow path downstream of the branch point.

In particular, it is possible for the second flow path to branch off from the first flow path at a branch point and to open again into the first flow path downstream of the branch point in an outflow point. In this case, a valve between the Abzweigungs- and the discharge point may be provided in the first flow path, which narrows or closes in the first position, the flow cross-section of the second flow path at the branch point or the orifice and in the second position the first flow path between the branch point and the confluence narrowed or closes.

In order to achieve different sound-damping properties in the different valve positions, it can be provided that the first flow path has a smaller length and / or a larger average flow cross-section than the second flow path.

The relatively large-volume filter housing and a relatively small flow cross-section having Ansaugkanalanordnung, as stated above, together form or comprise a Helmholtz resonator, which can absorb sound with a frequency close to its resonant frequency particularly well.

gegeben ist. Hierbei ist c die Schallgeschwindigkeit, S₀ die Querschnittsfläche der Öffnung am Resonatorhals (also der Ansaugkanalanordnung) , L die Länge des Resonatorhalses und V₀ das Volumen des eingeschlossenen Gases.By adjusting the valve means different flow paths, ie flow paths with different cross-section and / or different lengths can be selected, whereby the fundamental resonance frequency f of the Helmholtz resonator can vary, the first approximation by $$f=\frac{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="imgf0001.png"\; state="\{\{state\}\}">c</figure-callout>}}{2\pi }\sqrt{\frac{S_0}{V_{0}L}}$$

given is. Here, c is the speed of sound, S _{0 is} the cross-sectional area of the opening on the resonator neck (ie the intake channel arrangement), L is the length of the resonator neck and V _{0 is} the volume of the enclosed gas.

It is advantageous to damp low-frequency vibrations at low speeds, while with increasing engine speeds sufficient air flow through the Ansaugkanalanordnung is becoming increasingly important.

According to an advantageous development of the present invention, the dimensions of the intake duct arrangement and the filter housing are therefore selected so that they are in the second position of the valve device form a Helmholtz resonator with a fundamental resonance frequency in the range of about 30 to about 400 Hz.

It can further be provided that a portion of the intake passage arrangement in the first position of the valve device forms a cavity resonator with a basic resonance frequency in the range of about 100 to about 1000 Hz. This applies in particular in a configuration in which the second flow path branches off from the first flow path and the branch point is closed in the first position of the valve device, so that a portion of the second flow path forms a closed-end tube and thus a so-called "N4 resonator" , In this way, the part of the intake duct arrangement not used for directing the intake flow contributes to the soundproofing.

In particular, it can be provided that the air intake device further comprises a valve control / regulating device, which is designed to control an adjustment of the valve device, preferably in dependence on an engine speed of the motor vehicle, in particular occurring at low speeds low-frequency vibrations to dampen the air column between the intake port of the intake duct assembly and the valve flaps in the combustion chambers of the engine and to provide sufficient air flow at high engine speeds.

In practice, it has been found to be useful that the valve control / regulating device is designed to control the adjustment of the valve device so that the valve device for engine speeds below about 2000 to 3000 revolutions per minute in the second position, and is located at engine speeds above about 2000 to 3000 revolutions per minute in the first position. In the case of diesel engines, the limit may be closer to 2000 revolutions per minute, or even 2000 revolutions per minute. In the case of gasoline engines, the limit may be closer to 3000 rpm, or even 3000 rpm.

The present invention is not limited to exactly two different flow paths. It may be provided that n different flow paths are provided in the Ansaugkanalanordnung, and that the valve means between n different positions is adjustable, wherein the valve means is adapted, at least during a portion of an adjustment movement of the valve means from an n-th position out a flow cross-section locally reduce the nth flow path, where n is greater than or equal to 3.

In this way, the damping behavior of the air intake device over a wide speed range can be adapted to different requirements by the most appropriate flow path is selected.

Hereinafter, the present invention will be explained with reference to a preferred embodiment, which is shown in the accompanying figure. The figure is a simplified, schematic and not to scale.

Fig. 1 Figure 11 shows, in sub-figures (a) and (b), an air intake device 10 according to an embodiment of the present invention, wherein part figure (a) shows the valve means in the second position and part figure (b) shows the valve means in the first position.

As FIG. 1 shows, the air intake device 10 includes a filter housing 12 having disposed therein, not shown in the figures air filter. From an outside area A, unfiltered air can be sucked through a suction channel arrangement 14 into the filter housing 12, guided there by the air filter arranged therein, and the filtered air via a branched from the filter housing 12 connecting piece 13 and attached thereto, not shown here further line Combustion chambers of an internal combustion engine of a motor vehicle are supplied.

As will be explained below, with the air intake device 10 shown here, unwanted noise in different operating states of the engine can be largely damped.

In the intake duct assembly 14, a valve device 16 is arranged, which can be realized in the form of a flap valve 17 which is adjustable between a second position shown in part figure (a) and a first position shown in part figure (b).

The intake duct assembly 14 may include a first pipe section 18, which in the illustrated example forms a first flow path S1 from a suction port 21 to the filter housing 12, and may include a second pipe section 20, which in the illustrated example forms part of a second flow path S2 can also lead from the suction port 21 to the filter housing 12.

The first pipe section 18 may have a smaller length and a larger cross section compared to the second pipe section 20. The second pipe section 20 and thus the second flow path S2, with respect to a flow along the first flow path S1 downstream of the suction port 21 at a branch point 22 branch off from the first pipe section 18 and thus from the first flow path S1 and at an orifice 24, with respect to a flow along the first flow path S1 is preferably downstream of the branch point 22 and upstream of the filter housing 12, back into the first pipe section 18 and thus into the first flow path S1.

The Ansaugkanalanordnung 14 may be designed as a contiguous, preferably one-piece component, which opens at a junction 25 in the filter housing 12 and is connected at the junction 25, for example by a welding, screwing, clips or adhesive connection to the filter housing 12 (the Type of connection is in the figure not shown).

The flap valve 17 is in the example shown between the branch point 22 and the mouth point 24 to a plane to the Fig. 1 and 2 orthogonal axis 19 pivotally mounted on the first pipe section 18, so that it closes in the first position the flow cross section Q2 of the second pipe section 20 and thus the second flow path S2 at the branch point 22 and in the second position the flow cross section Q1 of the first pipe section 18 and thus of the first flow path S1 between the branch point 22 and the discharge point 24 closes.

In this way it is achieved that air sucked in by the intake duct arrangement 14, when the flap valve 17 is in the first position, passes almost completely along the first flow path S1 into the filter housing 12 and then when the flap valve 17 is in the second position is located, the sucked air almost completely along the second flow path S2 enters the filter housing.

In both the first and in the second position, the Ansaugkanalanordnung 14 forms with the volume of the filter housing 12 a Helmholtz resonator, wherein the Resonatorhals in the illustrated example in the first position by the first pipe section 18 and in the second position at least partially by the second Tube section 20 is formed.

Since the basic resonance frequency f of a Helmholtz resonator of length L ₀ and the cross-sectional area S _{0 of} the resonator neck depends, to a first approximation, on the equation (1) given above, in the illustrated example the resonance frequency is adjusted by adjusting the adjusting device from the first to the second position of the Helmholtz resonator shifted toward lower frequencies, since the length of the second flow path S2 here is greater than that of the first flow path S1 and the mean flow cross-section of the second flow path S2 is smaller than that of the first flow path S1.

At high engine speeds, however, it may be more advantageous to suck in air via the first pipe section (the first flow path) with a larger flow cross-section and thus to ensure a sufficient supply of air.

In the first position, the closed at one end second pipe section 20 also forms a cavity resonator (λ / 4 resonator), which can also contribute to reducing the noise emission.

The adjustment of the valve device 16 can be controlled via a not shown in the figure valve control / regulating device. For example, the control can be such that the valve device 16 for engine speeds below 2000 to 3000 revolutions per minute in the second position, so that low-frequency noise attenuated by the Helmholtz resonator formed by the filter housing 12 and intake passage 14, and that the engine speed valve device is in the first position above 2000 to 3000 revolutions per minute, so that a sufficient supply of air to the combustion chambers of the engine is ensured.

Claims (14)

An air intake device (10) for a motor vehicle, comprising
● a filter housing (12),
An intake passage arrangement (14) opening into the filter housing (12) for sucking air from an outer area (A) into the filter housing (12), wherein in the intake passage arrangement (14) a first flow path (S1) and at least one of the first flow path (S1) different, second flow path (S2) are provided, and
A valve device (16), which is adjustable at least between a first position and a second position, for influencing a flow of sucked air in the intake duct arrangement (14), wherein the valve device (16) is formed, at least during a portion of an adjusting movement of the valve device (16) second position to locally reduce a flow area (Q2) of the second flow path (S2),
characterized in that the valve means (16) is adapted to locally reduce at least during a portion of an adjustment movement of the valve means (16) from the first position a flow cross-section (Q1) of the first flow path (S1). Air intake device (10) according to claim 1,
characterized in that the valve device (16) is designed to increase locally at least during a portion of an adjusting movement of the valve device (16) from the first position to the second position, the flow cross section (Q2) of the second flow path (S2) and the flow cross section ( Q1) of the first flow path (S1) to reduce locally. Air intake device (10) according to claim 1 or 2,
characterized in that in the first position of the valve means (16) air sucked in through the intake duct arrangement (14) passes predominantly or essentially completely into the filter housing (12) on the first flow path (S1) and / or in the second position of the valve mechanism (16) through the intake duct arrangement (14). sucked air passes mainly or substantially completely on the second flow path (S2) in the filter housing. Air intake device (10) according to one of the preceding claims,
characterized in that the Ansaugkanalanordnung (14) is a single, preferably integrally formed component. Air intake device (10) according to one of the preceding claims,
characterized in that the first and second flow paths (S1, S2) open into one another upstream of the filter housing (12) at an orifice (24) with respect to a suction flow along the first flow path (S1). Air intake device according to claim 5
characterized in that the valve means (16) comprises a valve (17) provided upstream of the orifice (24) in or on the intake passage assembly (14) with respect to a suction flow along the first flow path (S1). Air intake device (10) according to one of the preceding claims,
characterized in that the suction channel assembly (14) has a single suction port (21), and that the second flow path (S2) is suctioned along the first flow path (S1) downstream of the suction port (21) at a branching point (22) thereof first flow path (S1) branches off. Air intake device (10) according to claim 7,
characterized in that the valve means (16) comprises a valve (17) provided with respect to a suction flow along the first flow path (S1) downstream of the branch point (22) in or on the suction channel assembly (14). Air intake device (10) according to one of the preceding claims,
characterized in that the first flow path (S1) has a smaller length and / or a larger average flow cross-section than the second flow path (S2). Air intake device (10) according to one of the preceding claims, in particular in combination with claim 9,
characterized in that the intake passage assembly (14) and the filter housing (12) in the second position of the valve means (16) form or include a Helmholtz resonator having a fundamental resonance frequency in the range of 30 to 400 Hz. Air intake device (10) according to one of the preceding claims, in particular in combination with claim 9,
characterized in that at least a portion of the intake duct assembly (14) in the first position of the valve means (16) forms a cavity resonator having a first fundamental resonance frequency in the range of 100 to 1000 Hz. Air intake device (10) according to one of the preceding claims,
characterized in that it further comprises a valve control / regulating device, which is designed to control an adjustment of the valve device (16), preferably in dependence on an engine speed of the motor vehicle. Air intake device (10) according to claim 12, in particular in combination with claim 9,
characterized in that the valve control means is arranged to control the adjustment of the valve means (16) such that the engine speed valve means (16) is below about 2000 to 3000 revolutions per minute in the second position is located at about 2000 to 3000 revolutions per minute in the first position for engine speeds. Air intake device according to one of the preceding claims,
characterized in that n different flow paths are provided in the Ansaugkanalanordnung, and that the valve means between n different positions is adjustable, wherein the valve means is adapted, at least during a portion of an adjustment movement of the valve means from an n-th position out a flow cross-section of the n- locally reduce flow path, where n ≥ 3.

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