Air filter assembly for cleaning an air stream for a utility vehicle

Abstract

The invention relates to an air filter assembly (10) for cleaning an air stream (18) for a commercial vehicle, in particular for an agricultural tractor (12), comprising a pre-filter (16) communicating with an air intake (14) and a first fine filter (20) which is provided downstream of the pre-filter (16) in the direction of the air stream (18) and, together with the pre-filter (16), is associated with an air filter part (24) which extends vertically in a predetermined installation position (22). A redundant second fine filter (26), which is associated with an air filter part (28) which extends horizontally in the predetermined installation position (22), follows the first fine filter (20) in the direction of the air stream (18), the horizontally extending air filter part (28) being a component of a syphon-like conduit region (30) which rises in a curved manner in the direction of an air outlet (32), starting from the redundant second fine filter (26).

Description

[0001] The invention relates to an air filter assembly for cleaning an air flow for a commercial vehicle, in particular for an agricultural tractor, comprising a pre-filter communicating with an air inlet and a first fine filter arranged downstream of the pre-filter in the direction of the air flow. Following the first fine filter in the direction of the air flow is a redundant second fine filter, which is assigned to an air filter section extending horizontally in a predetermined installation position of the air filter assembly.

[0002] Such an arrangement is disclosed, for example, in GB 2 055 719 A. This comprises an air intake stack mounted on a tiltable driver's cab of a truck. The stack has guide vanes arranged in the area of ​​an air inlet, by means of which an air stream drawn in via the air inlet can be set into swirling motions, so that coarse particles entrained in the air stream are thrown toward adjacent rubber discharge flaps and thus removed. The air stream passes through a conical filter element and a safety filter element arranged downstream of a rubber bellows, from which it then exits laterally toward an engine intake tract.

[0003] Such multi-stage air filter arrangements are typically used in areas where the ambient air is significantly polluted with dust. This is especially the case with commercial vehicles in the forestry and agricultural sectors, but also in the construction industry. The ambient air to be cleaned is typically fed into the intake tract of a diesel-powered combustion engine. The individual filters are housed in a common filter housing as cartridges that can be individually removed for maintenance or cleaning purposes. This housing is installed horizontally in the commercial vehicle. This prevents dust particles that have penetrated the filter housing from entering the downstream intake tract of the combustion engine unhindered if the cartridges are removed. This risk would exist particularly if the filter housing were mounted upright.

[0004] Both the necessity of horizontal installation and the accommodation of the individual filters in a common and thus comparatively bulky filter housing prevent optimal use of the installation space available on the vehicle.

[0005] In view of this, it is the object of the present invention to provide an air filter arrangement of the type mentioned at the outset which is improved with regard to the use of the installation space typically available in a commercial vehicle.

[0006] This object is achieved by an air filter arrangement having the features of patent claim 1.

[0007] The air filter arrangement for cleaning an air flow for a commercial vehicle, in particular for an agricultural tractor, comprises a pre-filter communicating with an air inlet and a first fine filter arranged downstream of the pre-filter in the direction of the air flow, which first fine filter, together with the pre-filter, is assigned to an air filter section which runs vertically in a predetermined installation position, wherein the first fine filter is followed in the direction of the air flow by a redundant second fine filter which is assigned to an air filter section which runs horizontally in the predetermined installation position, wherein the horizontally running air filter section is part of a siphon-like line region which, starting from the redundant second fine filter, rises in an arc in the direction of an air outlet.

[0008] In this way, a structurally divided arrangement of pre-filter and first fine filter on the one hand and redundant second fine filter on the other hand is possible, whereby the siphon-like rising line area prevents dust particles from reaching the area behind it in the direction of the air outlet when the redundant second filter is removed.

[0009] The actual filtering of the air flow takes place via the pre-filter and the first fine filter; these are therefore arranged directly one after the other in the vertically running air filter section. The pre-filter and the first fine filter form the main filter of the air filter assembly. The redundant second fine filter, present for reasons of operational safety, is merely an additional filter and can therefore be located at a distance from the main filter in the subsequent horizontally running air filter section. This type of design contributes to the high air flow in common commercial vehicles used in agriculture, forestry, and other applications.The design takes into account the structural conditions prevailing in the construction machinery sector, as it is conceivable, among other things, to design the vertically running air filter section in the form of an intake snorkel located outside the engine compartment, whereas the horizontally running air filter section can enter the engine compartment laterally in an area below an internal combustion engine. The use of an intake snorkel allows for an increase in the distance between the air inlet and the ground, thus allowing the intake of ambient air with a correspondingly lower dust load. As a result, the air filter arrangement according to the invention therefore enables better use of the installation space typically available in a commercial vehicle.

[0010] The installation position of the two air filter sections can be specified based on an imaginary vehicle plane spanned by a first axis oriented essentially in the longitudinal direction of the commercial vehicle and a second axis oriented essentially in the transverse direction of the commercial vehicle. Relative to this vehicle plane, the vertically extending air filter section is arranged upright on the commercial vehicle, while the horizontally extending air filter section is arranged horizontally.

[0011] Advantageous embodiments of the air filter arrangement according to the invention emerge from the subclaims.

[0012] The pre-filter is preferably designed as a centrifugal separator for separating coarse particles contained in the air stream being drawn in. The centrifugal separator comprises a plurality of air inlets, each of which is connected to an individual separator, which imparts a swirling motion to the passing air stream such that the coarse particles contained therein are thrown into a collection area surrounding the individual separators due to the resulting centrifugal forces.

[0013] To ensure consistent filter performance, the collection area within the centrifugal separator can be connected to a vacuum line for continuous extraction of the separated coarse particles. The vacuum line can either open into the low-pressure intake area of ​​an axial fan assembly included in an engine cooling system or be connected to a separate vacuum generator.

[0014] Furthermore, it is conceivable for the vertically running air filter section to be connected to the horizontally running air filter section via a flexible bellows. The flexible bellows allows for the compensation of operational movements or vibrations between the two sections. The use of a flexible bellows also allows the vertically running air filter section to be mounted on a driver's cab that is suspended from a supporting vehicle chassis.

[0015] For this purpose, at least one fastening element for mounting on a support structure of the driver's cab of the commercial vehicle can be provided on the vertically extending air filter section. The fastening element is, for example, a bracket that is integrally formed on a plastic housing encompassed by the air filter assembly.

[0016] Typically, the first fine filter comprises a pleated filter fleece as the active filter element. During operation, dust particles become trapped in it, which cannot be removed even by cleaning, for example, by blowing out with compressed air. To prevent degradation of the filter performance, the first fine filter can therefore be designed as a replaceable disposable filter cartridge.

[0017] In particular, the disposable filter cartridge can also be equipped with a sensor-detectable individual identification feature, which precludes further use of the disposable filter cartridge after the expiration of a specified service life. This identification feature could be, for example, an RFID tag that can be read using an on-board RFID receiver. The read identification feature is transmitted to a control unit, which, based on an operating hour counter started for the respective disposable filter cartridge, determines whether the specified service life has been exceeded. If this is the case, the control unit prevents the commercial vehicle from being used again and simultaneously issues a corresponding driver message.

[0018] The curved, rising line section can be designed as an elastic air hose. This is made of a heat-resistant rubber compound, such as Viton. This largely eliminates the possibility of transmission of operational movements from a connected vehicle component to the components of the vertically running air filter section.

[0019] Typically, a connector is provided at the air outlet for connecting to the intake tract of a vehicle unit configured as an internal combustion engine. The connector can be formed directly on the elastic air hose as part of the curved, rising line section. The connector is mounted hermetically, for example, using a hose clamp, to a connecting flange of the internal combustion engine that communicates with the intake tract.

[0020] Finally, it should be noted that the use of the air filter assembly according to the invention need not be limited to the purification of an air flow supplied to an internal combustion engine. Rather, other applications requiring reliable filtration of the ambient air are also possible, such as the air conditioning of a hermetically sealed driver's cab to protect against pesticides being applied.

[0021] The air filter assembly according to the invention for cleaning an air flow for a commercial vehicle is explained in more detail below with reference to the accompanying drawings. Identical reference numerals refer to identical or functionally comparable components. They show: Fig. 1 shows an embodiment of the air filter arrangement according to the invention for cleaning an air flow for a commercial vehicle, and Fig. 2 shows a commercial vehicle designed as an agricultural tractor, comprising the Fig. 1 shown air filter arrangement.

[0022] Fig. 1 shows an embodiment of the air filter arrangement 10 according to the invention, the structure and functioning of which will be explained below with reference to the Fig. 2 shown installed state on a commercial vehicle designed as an agricultural tractor 12.

[0023] The multi-stage air filter arrangement 10 comprises a pre-filter 16 communicating with an air inlet 14 and a first fine filter 20 arranged downstream of the pre-filter 16 in the direction of an air flow 18 to be cleaned. The first fine filter 20, together with the pre-filter 16, is assigned to an air filter section 24 extending vertically in a predetermined installation position 22.

[0024] The first fine filter 20 is followed by a redundant second fine filter 26 in the direction of the air flow 18 to be cleaned. The redundant second fine filter 26 is assigned to an air filter section 28 that runs horizontally in the specified installation position 22. The horizontally running air filter section 28 is part of a siphon-like duct section 30 that rises in an arc from the redundant second fine filter 26 toward an air outlet 32 ​​from which the cleaned air flow 18 exits.

[0025] According to Fig. 2 To specify the installation position 22 of the two air filter sections 24, 28, an imaginary vehicle plane 34 is used, which is spanned by a first axis 36 oriented substantially in the longitudinal direction of the agricultural tractor 12 and a second axis 38 oriented substantially in the transverse direction of the agricultural tractor 12. Relative to this vehicle plane 34, the vertically extending air filter section 24 is arranged upright and the horizontally extending air filter section 28 is arranged horizontally on the agricultural tractor 12.

[0026] The actual filtration of the air flow 18 is achieved by means of the pre-filter 16 and the first fine filter 20, which are therefore housed together in direct succession in the vertically extending air filter section 24. The pre-filter 16 and the first fine filter 20 form the main filter 40 of the air filter assembly 10. The redundant second fine filter 26, present for reasons of operational safety, merely represents an additional filter and is located at a distance from the main filter 40 in the subsequent horizontally extending air filter section 28.

[0027] How best in Fig. 2As can be seen, the vertically extending air filter section 24 is designed, for example, in the form of an intake snorkel 44 located outside an engine compartment 42 of the agricultural tractor 12, whereas the horizontally extending air filter section 28 enters the engine compartment 42 laterally in an area 46 below a vehicle unit designed as an internal combustion engine 48. The use of an intake snorkel 44 allows the distance between the air inlet 14 and the ground 50 to be increased, thus allowing the intake of ambient air with a correspondingly lower dust load.

[0028] The vertically extending air filter section 24, enclosed by the intake snorkel 44, is connected to the horizontally extending air filter section 28 via a flexible bellows 52. The flexible bellows 52 enables compensation of operational movements or vibrations between the two sections 24, 28, particularly in the case where the vertically extending air filter section 24 is attached, as here, to a driver's cab 56 that is suspended relative to a supporting vehicle chassis 54.

[0029] For this purpose, at least one fastening element 58 is provided on the vertically extending air filter section 24 for mounting on a support structure 60 of the driver's cab 56 of the agricultural tractor 12. The fastening element 58 is a holder 62, which is formed integrally on a plastic housing 64 encompassed by the air filter assembly 10 in the region of the intake snorkel 44.

[0030] The curved, rising line section 30 is designed as an elastic air hose 66. This consists of a heat-resistant rubber compound, for example, Viton. A connector 68 for connection to an intake tract 70 of the internal combustion engine 48 is provided at the air outlet 32. The connector 68 is formed directly on the elastic air hose 66 as a component of the curved, rising line section 30 and is mounted in an airtight manner by means of a hose clamp 72 to a connection flange 74 of the internal combustion engine 48 that communicates with the intake tract 70.

[0031] The pre-filter 16 is inserted into the plastic housing 64 in the form of a cassette-like insert 76 in an end region 78 of the intake snorkel 44, accessible from the outside. The cassette-like insert 76 is constructed in several parts and can be removed by hand for disassembly and cleaning.

[0032] In this case, the pre-filter 16 is designed as a centrifugal separator 80 for separating coarse particles contained in the intake air stream 18. The centrifugal separator 80 comprises a plurality of air inlet openings 82, each of which is connected to an individual separator 84, which imparts a swirling motion to the passing air stream 18 such that the coarse particles contained therein are thrown into a collection area 86 surrounding the individual separators 84 due to the centrifugal forces that occur.

[0033] To ensure consistent filter performance, the collection area 86 provided within the centrifugal separator 80 communicates with a vacuum line 88 for continuously extracting the separated coarse particles. The vacuum line 88 opens into a low-pressure intake area 90 of an axial fan arrangement (not shown) included in an engine cooling system.

[0034] The pre-cleaned air stream 18 exiting the centrifugal separator 80 is then fed to the first fine filter 20. To remove any remaining dust particles, the first fine filter 20 comprises a pleated filter fleece (not shown) as an active filter element. During operation, dust particles become trapped therein and cannot be removed even by cleaning, for example, by blowing them out with compressed air. To prevent degradation of the filter performance, the first fine filter 20 is therefore designed as a replaceable disposable filter cartridge 92. The disposable filter cartridge 92 is located in a receiving area within the plastic housing 64 that can be hermetically sealed by a cover 94.

[0035] The second fine filter 26 arranged in the vertically extending line section 24 simultaneously forms a plastic transition piece 96, to which the flexible bellows 52 is attached at one end and the elastic air hose 66 at the other. The transition piece 96 can be removed as needed for the purpose of cleaning or replacing the second fine filter 26 or a filter-active element arranged therein. The elastic air hose 66, which rises towards the air outlet 32, largely prevents, due to gravity, any dust particles released in the process and which may have accumulated in this area from passing towards the intake tract 70. For this purpose, the second fine filter 26 is preferably located at the lowest point of the siphon-like line section 30.

[0036] An optional development of the air filter assembly 10 provides that the disposable filter cartridge 92 enclosed by the first fine filter 20 is equipped with a sensor-detectable individual identification feature 98, on the basis of which further use of the disposable filter cartridge 92 after the expiration of a specified service life is excluded. The identification feature 98 is an RFID tag 100 that can be read by a vehicle-mounted RFID receiver 102. The read identification feature 98 is transmitted to a control unit 104, which determines, based on an operating hour counter started for the respective disposable filter cartridge 92, whether the specified service life has been exceeded. If this is the case, the control unit 104 prevents the agricultural tractor 12 from being started again and simultaneously outputs corresponding driver information.The latter is done via a user interface 106 connected to the control unit 104, which is located in the driver's cab 56 of the agricultural tractor 12.

Claims

1. Air filter assembly for cleaning an air stream for a commercial vehicle, in particular for an agricultural tractor, comprising a pre-filter (16), which communicates with an air inlet (14), and a first fine filter (20), which is provided downstream of the pre-filter (16) in the direction of the air stream (18) and, together with the pre-filter (16), is associated with an air filter portion (24) which extends vertically in a predetermined installation position (22), wherein the first fine filter (20) is followed in the direction of the air stream (18) by a redundant second fine filter (26), which is associated with an air filter portion (28) which extends horizontally in the predetermined installation position (22), characterized in that the horizontally extending air filter portion (28) is part of a syphon-like line region (20) which rises in a curved manner from the redundant second fine filter (26) towards an air outlet (32).

2. Air filter assembly according to Claim 1, characterized in that the pre-filter (16) is in the form of a centrifugal separator (80) for separating out coarse particles present in the air stream (18).

3. Air filter assembly according to Claim 2, characterized in that a collection region (86) provided inside the centrifugal separator (80) communicates with a vacuum line (88) for the continuous suction of the coarse particles separated out.

4. Air filter assembly according to at least one of the preceding claims, characterized in that the vertically extending air filter portion (24) is connected to the horizontally extending air filter portion (28) via a flexible bellows (52).

5. Air filter assembly according to at least one of the preceding claims, characterized in that at least one fastening element (58) is provided on the vertically extending air filter portion (24) for mounting on a supporting structure (60) of a driver's cab (56) of the commercial vehicle (12).

6. Air filter assembly according to at least one of the preceding claims, characterized in that the first fine filter (20) comprises a folded filter nonwoven as the active filtering element.

7. Air filter assembly according to at least one of the preceding claims, characterized in that the first fine filter (20) is in the form of an exchangeable single-use filter cartridge (92).

8. Air filter assembly according to Claim 7, characterized in that the single-use filter cartridge (92) is equipped with an individual identification feature (98) which can be detected by sensors.

9. Air filter assembly according to at least one of the preceding claims, characterized in that the line region (30) which rises in a curved manner is in the form of an elastic air hose (66).

10. Air filter assembly according to at least one of the preceding claims, characterized in that a fitting (68) for connection to an intake tract (70) of a vehicle unit in the form of an internal combustion engine (48) is provided on the air outlet (32).

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