PARTICLE DISCHARGE DEVICE, FILTER ARRANGEMENT AND METHOD

Description

Technical area

[0001] The present invention relates to a particle discharge device for a filter arrangement, a filter arrangement with such a particle discharge device and a method for producing such a particle discharge device. State of the art

[0002] In the automotive sector, especially in trucks, construction machinery, or agricultural vehicles—that is, in so-called "heavy-duty" applications—round air filter arrangements with centrifugal pre-separation of particles or cyclone separators are often used. Pre-separation of particles makes it possible to keep the particle load of the actual filter element low. This increases the service life of the filter element.

[0003] DE 42 40 048 A1 discloses a dust discharge valve. EP 2 703 059 A2 discloses a filter receptacle with a housing comprising a dust discharge port, on which a particle discharge device in the form of a lip valve, in particular a so-called "duckbill valve," is provided. This lip valve can be opened, for example, by means of a pulsating operation of an internal combustion engine coupled to the filter receptacle in order to discharge the particles from the filter receptacle.

[0004] WO 2011 / 124675 A1 describes a cyclone separator, on the housing of which a dust discharge with such a lip valve is also provided. Disclosure of the invention

[0005] It is therefore an object of the invention to provide an improved particle discharge device for a filter arrangement.

[0006] Accordingly, a particle discharge device for a filter arrangement is proposed.The particle discharge device comprises a housing and at least one particle discharge flap formed in one piece with the housing, wherein the at least one particle discharge flap can be moved from a closed state to an open state for discharging particles from the filter arrangement, and wherein the at least one particle discharge flap, in the closed state, rests against a valve seat of the housing which extends at least partially around an axis of symmetry of the housing, wherein the axis of symmetry is oriented parallel to a direction of gravity, and the particle discharge device further comprises a base which at least partially closes the housing at the end face, and precisely one particle discharge flap which is connected in one piece to the base and is oriented perpendicular to the axis of symmetry in the closed state, wherein the particle discharge device is a one-piece plastic injection-molded component made of an elastomer.

[0007] The particle discharge device can also be referred to as a particle discharge device, particle discharge valve, or dust discharge valve. The particle discharge device is particularly suitable for discharging or discharging particles from the filter assembly, in particular from a filter housing of the filter assembly. The housing of the particle discharge device is preferably tubular and constructed substantially rotationally symmetrically to the axis of symmetry. The axis of symmetry is preferably oriented parallel to or coincides with a direction of gravity.

[0008] "One-piece" or "single-piece" in this context means that the housing and the particle discharge flap form a single component and are not constructed from separate parts. This means, in particular, that the housing and the particle discharge flap cannot be separated from each other without causing damage. In particular, the housing and the particle discharge flap are constructed from a single piece of material. "Single-piece" in this context means that the housing and the particle discharge flap are made entirely of the same material.

[0009] The particle discharge flap is preferably a flat or planar component which, in the closed state, is oriented perpendicular to the axis of symmetry. In the closed state, the particle discharge flap is preferably arranged within, in particular at least partially within, the housing. Preferably, the particle discharge flap is moved from the open state to the closed state when an internal combustion engine connected to the filter arrangement is started up. This means that the particle discharge flap is moved from the open state to the closed state by a negative pressure generated by the internal combustion engine. The particle discharge flap can be moved from the closed state to the open state and vice versa as often as desired. The open state is preferably an initial state of the particle discharge flap.This means that as long as the internal combustion engine is not in operation, the particle discharge flap is in the open state.

[0010] The valve seat is, in particular, annular. According to the invention, the valve seat cannot completely revolve around the axis of symmetry. In this case, the valve seat is annularly closed. However, the valve seat can also only partially revolve around the axis of symmetry. In this case, the valve seat is not circumferentially closed. For example, the valve seat can only revolve two-thirds of the way around the housing when viewed along a circumferential direction of the housing. The valve seat is, in particular, oriented perpendicular to the axis of symmetry. In the present case, "perpendicular" can be understood to mean, in particular, an angle of 90° ± 10°, preferably 90° ± 5°, more preferably 90° ± 3°, more preferably 90° ± 1°, more preferably exactly 90°.

[0011] Due to the fact that the valve seat is provided which at least partially encircles the axis of symmetry of the housing and against which the particle discharge flap rests in the closed state, a smaller installation space for the particle discharge device can be achieved compared to a lip valve as previously explained along the axis of symmetry.

[0012] In embodiments, the at least one particle discharge flap is elastically deformable for moving it from the closed state to the open state. "Elastic deformability" in this context refers to reversible deformability. This means that the particle discharge flap can be moved from the closed state to the open state and vice versa as often as desired. When moving the particle discharge flap from the closed state to the open state, the particle discharge flap is bent or curved, in particular, into an arc. This creates a large outlet cross-section for the particles to be discharged.

[0013] In embodiments, the at least one particle discharge flap can be moved from the closed state to the open state by means of a weight force of the particles acting on the at least one particle discharge flap. This means that the particle discharge flap automatically moves from the closed state to the open state due to the weight force of the particles. As soon as the weight force of the particles no longer acts on the particle discharge flap, it automatically moves from the open state back to the closed state. The movement from the open state to the closed state can also be accomplished or at least assisted by a negative pressure generated by the internal combustion engine.Furthermore, the particle discharge flap can also be additionally or optionally moved from the closed state to the open state and vice versa by a load change of an internal combustion engine connected to the filter arrangement.

[0014] In embodiments not according to the invention, the particle discharge device further comprises a first particle discharge flap, a second particle discharge flap, and a central web that integrally connects the first particle discharge flap and the second particle discharge flap to the housing. The central web is preferably arranged perpendicular to the axis of symmetry. The central web extends transversely through the housing, with the two particle discharge flaps being connected to the central web via hinge sections. In particular, the housing comprises a tubular base section to which the central web is integrally connected, in particular made of a single material.

[0015] According to the invention, the particle discharge device further comprises a base, which at least partially closes the housing at the front, and precisely one particle discharge flap, which is integrally connected to the base. The base closes approximately one-third of the cross-sectional area of ​​the housing or the base section of the housing. Accordingly, in the closed state, the particle discharge flap covers two-thirds of the cross-sectional area of ​​the housing or the base section of the housing. The particle discharge flap can be connected to the base via the aforementioned hinge section. This achieves a large outlet cross-section for the particles to be discharged.

[0016] In embodiments, the particle discharge device is a one-piece plastic injection-molded component made of an elastomer. For example, the particle discharge device can be made of rubber, an ethylene propylene diene rubber (EPDM), an acrylonitrile butadiene rubber (NBR), or a thermoplastic elastomer (TPE), such as a thermoplastic polyurethane (TPU). Using the aforementioned materials, the particle discharge device, and in particular the particle discharge flap, is elastically deformable.

[0017] In embodiments not according to the invention, the valve seat extends completely around the axis of symmetry. This means that, as previously mentioned, the valve seat is annularly closed. Alternatively, the valve seat can also extend only partially around the axis of symmetry. In this case, too, the valve seat can be annular. However, the valve seat is then open across its circumference.

[0018] Furthermore, a filter arrangement with a filter housing and such a particle discharge device is proposed, which is arranged on a particle discharge nozzle of the filter housing.

[0019] The filter housing preferably comprises a filter housing bowl and a filter housing cover, which is detachably attached to the filter housing bowl. A filter element is accommodated in the filter housing bowl. The filter element can be replaced by removing the filter housing cover from the filter housing bowl. The particle discharge nozzle is preferably provided on the filter housing cover. The particle discharge device is plugged onto the particle discharge nozzle. The elastic deformability of the particle discharge device enables it to be easily plugged onto the particle discharge nozzle. The filter arrangement is particularly designed to filter fluids, such as air, or other gases, liquids, in particular liquid operating media of a vehicle, in particular a motor vehicle, such as oil, water, gasoline, kerosene, or urea solution. In particular, the filter arrangement is an air filter arrangement.The filter assembly can be used in motor vehicles, watercraft, rail vehicles, agricultural vehicles, construction machinery, aircraft, or the like. Furthermore, the filter assembly can also be used in immobile applications, such as in building services engineering.

[0020] Furthermore, a method for producing a particle discharge device for a filter assembly as described above is proposed. The method comprises the steps: a) producing a housing, and b) producing at least one particle discharge flap formed integrally with the housing.

[0021] Steps a) and b) are performed simultaneously, preferably using a plastic injection molding tool. The housing is manufactured as a single piece, particularly in one piece, with the particle discharge flap. However, this does not preclude the use of different materials, for example, materials with different elasticities, for the housing and the particle discharge flap. A two-component plastic injection molding process can be used for this purpose, for example.

[0022] After or during step b), the at least one particle discharge flap is separated from a valve seat of the housing using a separating manufacturing process. For example, the particle discharge flap can be separated from the valve seat using a cutting edge or a knife. Alternatively, a laser separation process or a water jet separation process can also be used. Alternatively, the particle discharge device can also be manufactured in such a way that separating the particle discharge flap from the valve seat is not necessary. For this purpose, for example, a gap can be provided in the plastic injection molding tool between the particle discharge flap and the valve seat. In this case, separating the particle discharge flap from the valve seat is not necessary. The particle discharge device can then be used immediately after demolding from the plastic injection molding tool. Short description of the drawings

[0023] It shows: Fig. 1: a schematic perspective view of an embodiment of a filter arrangement; Fig. 2: a schematic perspective view of a non-inventive embodiment of a particle discharge device for the filter arrangement according to Fig. 1 ; Fig. 3: a schematic sectional view of the particle discharge device according to Fig. 2 ; Fig. 4: a schematic perspective view of an embodiment of a particle discharge device according to the invention for the filter arrangement according to Fig. 1 ; Fig. 5: a schematic sectional view of the particle discharge device according to Fig. 4 ; Fig. 6: a schematic perspective view of a further non-inventive embodiment of a particle discharge device for the filter arrangement according to Fig. 1 ; Fig. 7: a schematic sectional view of the particle discharge device according to Fig. 6; and Fig. 8: a schematic block diagram of an embodiment of a method for producing a particle discharge device for the filter arrangement according to Fig. 1 .

[0024] In the figures, identical or functionally equivalent elements have been given the same reference numerals unless otherwise indicated. Embodiment(s) of the invention

[0025] The Fig. 1shows a schematic perspective view of an embodiment of a filter arrangement 1. The filter arrangement 1 can be suitable for filtering water, urea solution, air, oil or fuels such as diesel fuel, kerosene or gasoline. In particular, the filter arrangement 1 is used in motor vehicles, in particular in passenger cars, trucks, construction vehicles or agricultural machinery, in watercraft, in rail vehicles or in aircraft. Furthermore, the filter arrangement 1 can be used, for example, in building technology. The filter arrangement 1 is preferably suitable for use under high dust loads or under high particle loads. The filter arrangement 1 is in particular an air filter arrangement and is suitable for filtering combustion air of an internal combustion engine.

[0026] The filter assembly 1 comprises a filter housing 2 with a filter housing bowl 3 and a filter housing cover 4. The filter housing bowl 3 and the filter housing cover 4 can be designed, for example, as plastic components, in particular as plastic injection-molded components. The filter housing cover 4 is removable from the filter housing bowl 3 and detachably connected to the filter housing bowl 3.

[0027] The filter housing bowl 3 can be permanently attached in or to a vehicle, for example, to a supporting body structure of the vehicle. For this purpose, the filter housing bowl 3 has molded-on attachment sections 5, 6. A replaceable filter element (not shown) is accommodated in the filter housing bowl 3. The filter element can be removed from the filter housing bowl 3 and thus replaced after removing the filter housing cover 4 from the filter housing bowl 3.

[0028] The filter housing cover 4 comprises a plurality of cyclone separators 7, of which Fig. 1 only one is provided with a reference symbol. The cyclone separators 7 are suitable for separating particles P from the raw air RO supplied to the filter arrangement 1. The raw air RO freed of the particles P then flows through the filter element and leaves the filter arrangement 1 as clean air RL. The particles P include, for example, small stones, dust, sand, soil, plant parts, or the like. The cyclone separators 7 separate the particles P from the raw air RO in the manner of a centrifugal separator. The cyclone separators 7 are covered by a cover (not shown).

[0029] Viewed with respect to a direction of gravity g, the filter housing cover 4 comprises, at a lowest point or lower region, a particle discharge nozzle 8 for discharging the particles P from the filter housing 2 or from the filter housing cover 4. The particle discharge nozzle 8 is tubular and is preferably arranged such that it runs in the direction of gravity g. A particle discharge device 9, to be explained later, is attached to the particle discharge nozzle 8. The particle discharge device 9 can also be referred to as a particle discharge valve or a dust discharge valve.

[0030] During operation of an internal combustion engine with such a filter assembly 1, the assembly is connected to the intake tract of the internal combustion engine. During operation, the internal combustion engine draws in the raw air RO laden with particles P. The raw air RO to be cleaned is largely freed of particles P by means of the cyclone separators 7, which collect due to gravity in the lower area of ​​the filter housing cover 4 or in the particle discharge nozzle 8.

[0031] In this respect, the particles P are pre-separated in the manner of a centrifugal separator. This type of particle separation can also be referred to as rotary separation or centrifugal separation. To remove or discharge the collected particles P from the filter housing 2, the particle discharge nozzle 8 with the particle discharge device 9 is provided.

[0032] With the help of this pre-separation, more than 80% of the particles P contained in the raw air RO can be separated. This means that a pre-separation efficiency of more than 80% can be achieved. The raw air RO, pre-cleaned of particles P in this way, flows from one raw side of the filter element to one clean side. The remaining particles P are separated using a filter medium in the filter element. The clean air RL then flows to the internal combustion engine.

[0033] The Fig. 2 shows a schematic perspective view of a non-inventive embodiment of a particle discharge device 9A. The Fig. 3 shows a schematic sectional view of the particle discharge device 9A. Fig. 2 and 3 referred to at the same time.

[0034] The particle discharge device 9A comprises a tubular housing 10. The housing 10 is preferably rotationally symmetrical to a central or symmetry axis 11. The symmetry axis 11 can simultaneously be an axis of symmetry of the particle discharge nozzle 8. The symmetry axis 11 runs in the direction of gravity g or coincides with it.

[0035] The housing 10 comprises a tubular base section 12 in which the particle discharge nozzle 8 is accommodated. An annular groove 13 is provided on the outside of the base section 12 and extends around it. The annular groove 13 is rectangular in cross-section. To simplify sliding the particle discharge device 9A onto the particle discharge nozzle 8, the orientation of the Fig. 3 On the upper side of the base section 12, a chamfer 14 is provided which runs completely around the axis of symmetry 11.

[0036] In the orientation of the Fig. 3Provided below the annular groove 13 and on the inside of the base section 12 is an engagement section 15 that completely surrounds the axis of symmetry 11. The engagement section 15 can be an annular groove with a semicircular cross-section. The particle discharge nozzle 8 has a counter-engagement section corresponding to the engagement section 15, for example in the form of a circumferential rib, which is suitable for positively engaging the engagement section 15. A positive connection is created by the interlocking or engaging of at least two connection partners, in this case the engagement section 15 and the counter-engagement section of the particle discharge nozzle 8. This allows the particle discharge device 9A to be captively attached to the particle discharge nozzle 8.

[0037] The base section 12 has, facing away from the bevel 14, a valve seat 16 that completely surrounds the axis of symmetry 11. The valve seat 16 can be triangular in cross-section. The valve seat 16 extends annularly around the axis of symmetry 11. Viewed along a circumferential direction U of the housing 10, the valve seat 16 is annularly closed. The valve seat 16 is oriented perpendicular to the axis of symmetry 11. "Perpendicular" in this case means an angle of 90° ± 10°, preferably 90° ± 5°, more preferably 90° ± 3°, more preferably 90° ± 1°, more preferably exactly 90°.

[0038] In addition to the base section 12, the housing 10 comprises a central web 17 oriented perpendicular to the axis of symmetry 11, which is connected to the base section 12 at both ends. A first particle discharge flap 18 and a second particle discharge flap 19 are connected in one piece to the central web 17. The particle discharge flaps 18, 19 can also be referred to as valve disks, particle discharge lips or particle discharge valve bodies. The particle discharge flaps 18, 19 are elastically deformable and can be moved from a closed state Z1, in which the particle discharge flaps 18, 19 rest against the valve seat 16, to an open state Z2, in which the particle discharge flaps 18', 19' do not rest against the valve seat 16. In the open state Z2, the particle discharge flaps are in the Fig. 3designated by the reference numerals 18', 19'. In the closed state Z1, the particle discharge flaps 18, 19 are oriented perpendicular to the axis of symmetry 11. In the closed state Z1, the particle discharge flaps 18, 19 are arranged within, in particular at least partially within, the housing 10.

[0039] The particle discharge device 9A is a plastic component. In particular, the particle discharge device 9A is a plastic injection-molded component. The particle discharge device 9A is a one-piece or single-piece, in particular single-material, component. "One-piece" or "single-piece" in this case means that the housing 10 with the base section 12 and the central web 17, as well as the particle discharge flaps 18, 19, form a common component and are not composed of different components. This means that the particle discharge flaps 18, 19, the central web 17, and the base section 12 can only be separated from one another by destroying them. "Piecemeal" in this case means that the housing 10 with the base section 12 and the central web 17, as well as the particle discharge flaps 18, 19, are made entirely of the same material.The material used for the particle discharge device 9A is, for example, rubber, an ethylene-propylene-diene rubber (EPDM), an acrylonitrile-butadiene rubber (NBR) or a thermoplastic elastomer (TPE), for example a thermoplastic polyurethane (TPU).

[0040] During production of the particle discharge device 9A, it is manufactured as a one-piece component in a plastic injection mold. After the particle discharge device 9A has been demolded from the plastic injection mold, the particle discharge flaps 18, 19 are initially connected to the valve seat 16 as a single piece. The particle discharge flaps 18, 19 are then completely separated from the valve seat 16 around the axis of symmetry 11. For this purpose, a separating manufacturing process is used. For example, a knife, a cutting edge, a cutting disk, a laser beam cutting process, or a water jet cutting process can be used to separate the particle discharge flaps 18, 19. The particle discharge flaps 18, 19 are then only connected to the housing 10 via the central web 17. In the area of ​​the central web 17, however, a connection between the particle discharge flaps 18, 19 and the valve seat 16 can also remain.

[0041] The functionality of the particle discharge device 9A is as follows. Before the internal combustion engine is started up, the particle discharge flaps 18', 19' are in the open state Z2 due to their elastic deformability and their own weight. As soon as the internal combustion engine is started up, it generates a negative pressure that moves the particle discharge flaps 18, 19 into the closed state Z1 and sucks them against the valve seat 16. The particles P separated from the raw air RO by the cyclone separators 7 collect on the particle discharge flaps 18, 19, which remain in their closed state Z1.

[0042] The particle discharge flaps 18, 19 are moved from the closed state Z1 to the open state Z2 either by a weight force G of the particles P and / or by a load change of the internal combustion engine. The particles P can now fall out of the particle discharge device 9A in the direction of gravity g. As soon as the weight force G no longer acts on the particle discharge flaps 18, 19 or as soon as the load change is completed, the particle discharge flaps 18, 19 are moved from the open state Z2 to the closed state Z1. The open state Z2 is maintained, for example, for a few fractions of a second to a few seconds.

[0043] The Fig. 4 shows a schematic perspective view of an embodiment of a particle discharge device 9B according to the invention. Fig. 5 shows a schematic sectional view of the particle discharge device 9B. Fig. 4 and5 referred to at the same time.

[0044] Like the particle discharge device 9A, the particle discharge device 9B comprises a housing 10 that is tubular and rotationally symmetrical to a central or symmetry axis 11. The housing 10 comprises a base portion 12 with a circumferential annular groove 13 as previously explained, a chamfer 14, an engagement portion 15, and a valve seat 16.

[0045] In contrast to the particle discharge device 9A, however, the valve seat 16 is not designed to completely encircle the axis of symmetry 11. Viewed in a circumferential direction U of the housing 10, the valve seat 16 only partially encircles the axis of symmetry 11. For example, viewed in the circumferential direction U, the valve seat 16 encircles the axis of symmetry 11 by two-thirds of the circumference of the housing 10.

[0046] In addition to the base section 12, the housing 10 comprises a base 20 partially closing the base section at the front. The base 20 is connected to the base section 12 in one piece, in particular in a single piece. Provided on the base 20 is precisely one particle discharge flap 18, as previously explained, which is elastically deformable. The particle discharge flap 18 is connected to the base 20 via a hinge section 21. The particle discharge flap 18 has a thinner wall than the base 20.

[0047] In contrast to the particle discharge device 9A, the particle discharge device 9B does not have two particle discharge flaps 18, 19, but only one particle discharge flap 18. The bottom 20 closes approximately one-third of a cross-sectional area of ​​the base section 12. The particle discharge flap 18, in contrast, closes approximately two-thirds of the cross-sectional area in a closed state Z1 thereof.

[0048] As previously mentioned, the particle discharge device 9B is a one-piece, in particular a one-piece component, in particular a plastic injection-molded component. The particle discharge device 9B is preferably a plastic injection-molded component and can be made, for example, of rubber, EPDM, NBR, or TPE. During the manufacture of the particle discharge device 9B, the particle discharge flap 18 is initially connected in one piece to the valve seat 16.

[0049] To enable opening of the particle discharge flap 18, the particle discharge flap 18 is separated from the valve seat 16 after demolding the particle discharge device 9B from a plastic injection mold. This can be done using a separating manufacturing process, as previously explained with reference to the particle discharge device 9A.

[0050] The functionality of the particle discharge device 9B essentially corresponds to the functionality of the particle discharge device 9A. Initially, the particle discharge flap 18' is in an open state Z2. When the internal combustion engine is started up, the particle discharge flap 18' is moved from the open state Z2 to the closed state Z1, in which the particle discharge flap 18 rests sealingly against the valve seat 16.

[0051] Particles P accumulating on the particle discharge flap 18 during operation of the internal combustion engine act with their weight G on the particle discharge flap 18, which is thereby moved from the closed state Z1 to the open state Z2, whereby the particles P can be discharged. Alternatively or additionally, the particle discharge flap 18 can also be moved from the closed state Z1 to the open state Z2 and back by a load change of the internal combustion engine.

[0052] The Fig. 6 shows a schematic perspective view of a further non-inventive embodiment of a particle discharge device 9C. The Fig. 7 shows a schematic sectional view of the particle discharge device 9C.

[0053] The particle discharge device 9C, like the particle discharge devices 9A, 9B, comprises a housing 10 that is rotationally symmetrical to a central or symmetry axis 11, with a base portion 12 that has a circumferential annular groove 13 on the outside and a chamfer 14 and an engagement portion 15 on the inside. Furthermore, a valve seat 16 is provided on the base portion 12. As with the particle discharge device 9B, the valve seat 16 does not completely revolve around the symmetry axis 11, but only partially.

[0054] As with the particle discharge device 9B, the housing 10 is partially closed by means of a base 20. The base 20 occupies approximately one-third of the cross-sectional area of ​​the base section 12. A particle discharge flap 18, as previously explained, is integrally formed on the base 20 via a hinge section 21. In a closed state Z1, the particle discharge flap 18, however, occupies approximately two-thirds of the cross-sectional area of ​​the base section 12.

[0055] In contrast to the particle discharge device 9B, the particle discharge device 9C is manufactured such that the particle discharge flap 18 is not integrally connected to the valve seat 16 after the particle discharge device 9C has been removed from a plastic injection mold. For this purpose, a gap 22, already provided in the plastic injection mold, is placed between the valve seat 16 and the particle discharge flap 18. This means that the particle discharge flap 18 does not need to be separated from the valve seat 16 after the particle discharge device 9C has been removed from the mold.

[0056] The Fig. 7shows the particle discharge flap 18" in a demolding state Z3. In the demolding state Z3, the particle discharge flap is provided with the reference number 18". From the demolding state Z3, the particle discharge flap 18" can be moved into the closed state Z1 as previously explained and into an open state Z2 as previously explained. The demolding state Z3 is between the closed state Z1 and the open state Z2.

[0057] The particle discharge device 9C, like the particle discharge devices 9A, 9B, is a one-piece, in particular a single-material component, in particular a plastic injection-molded component. The particle discharge device 9C can be made, for example, of rubber, EPDM, NBR, or TPE.

[0058] The previously described different embodiments of the particle discharge device 9A, 9B, 9C combine good discharge performance with a small overall volume, viewed along the symmetry axis 11. With the aid of the particle discharge flap 18 or the particle discharge flaps 18, 19, a large open discharge cross-section can be achieved. This results in very good discharge performance and a very low risk of clogging.

[0059] During operation of the respective particle discharge device 9A, 9B, 9C, a continuous discharge of the particles P is observed. The increase in the weight force G on the particle discharge flap 18 or on the particle discharge flaps 18, 19 due to the separated particles P causes a sudden opening of the respective particle discharge device 9A, 9B, 9C. Upon opening, a large cross-section of the particle discharge nozzle 8 is released, whereby the particles P are reliably discharged.

[0060] The Fig. 8shows a schematic block diagram of an embodiment of a method for manufacturing the particle discharge devices 9A, 9B, 9C as previously explained. In the method, the housing 10 is first manufactured in a step S1. At the same time, in a step S2, at least one particle discharge flap 18, 19 formed integrally with the housing 10 is manufactured. Steps S1 and S2 are preferably performed simultaneously using a plastic injection molding tool.

[0061] After or during step S2, the at least one particle discharge flap 18, 19 can be separated from the valve seat 16 of the housing 10 using a separating manufacturing process. For example, a cutting edge, a knife, or a cutting disk can be used for the separating manufacturing process. Alternatively, however, a laser cutting process or a water jet cutting process can also be used. Furthermore, as previously mentioned, the gap 22 can already be provided in the plastic injection molding tool, so that separating the at least one particle discharge flap 18, 19 from the valve seat 16 is unnecessary. Reference symbols used:

[0062] 1Filter assembly 2Filter housing 3Filter housing bowl 4Filter housing cover 5Mounting section 6Mounting section 7Cyclone separator 8Particle discharge nozzle 9Particle discharge device 9AParticle discharge device 9BParticle discharge device 9CParticle discharge device 10Housing 11Axis of symmetry 12Base section 13Annular groove 14Bevel 15Engagement section 16Valve seat 17Center web 18Particle discharge flap 18'Particle discharge flap 18"Particle discharge flap 19Particle discharge flap 19'Particle discharge flap 20Bottom 21Joint section 22Gap gGravity direction GGeight force RLReed air RORaw air PParticles S1Step S2Step UCircumferential direction Z1State Z2State Z3Demolding state

Claims

1. A particulate discharge device (9B) for a filter assembly (1), having a housing (10) and at least one particulate discharge flap (18, 18', 19, 19') designed in one piece with the housing (10), wherein the at least one particulate discharge flap (18, 18', 19, 19') can be moved from a closed state (Z1) to an open state (Z2) for discharging particulate matter (P) from the filter assembly (1) and wherein the at least one particulate discharge flap (18, 18', 19, 19') rests, in the closed state (Z1), against a valve seat (16) of the housing (10), said valve seat extending at least partially around a symmetry axis (11) of the housing (10), wherein the symmetry axis (11) is oriented parallel to a direction of gravity and the particulate discharge device (9B) furthermore comprises a bottom (20) which at least partially closes the front face of the housing (10), and precisely one particulate discharge flap (18, 18') connected in one piece to the bottom (20) and oriented perpendicular to the symmetry axis (11) in the closed state (Z1), and wherein the particulate discharge device (9B) is a plastic injection molded component made of an elastomer in one piece.

2. The particulate discharge device according to claim 1, wherein the particulate discharge flap (18, 18', 19, 19') is elastically deformable for moving it from the closed state (Z1) to the open state (Z2).

3. The particulate discharge device according to claim 1 or 2, wherein the particulate discharge flap (18, 18', 19, 19') can be moved from the closed state (Z1) to the open state (Z2) using a weight (G) of the particulates (P) acting on the at least one particulate discharge flap (18, 18', 19, 19').

4. A filter assembly (1) having a filter housing (2) and a particulate discharge device (9B) according to one of the claims 1 to 3, which is disposed on a particulate discharge nozzle (8) of the filter housing (2).

5. A method for manufacturing a particulate discharge device (9B) according to one of the claims 1 to 3, comprising the steps of: a) manufacturing (S1) a housing (10), and b) manufacturing (S2) at least one particulate discharge flap (18, 18', 19, 19') designed in one piece with the housing (10), wherein after or during the step b) the at least one particulate discharge flap (18, 18', 19, 19') is separated from a valve seat (16) of the housing (10) using a separating manufacturing method.