Patent ID: 12201924

In the Figures, same or functionally the same elements, inasmuch as nothing else is mentioned, are provided with the same reference characters.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS.1to3show respectively a schematic partial section view of an embodiment of a filter assembly1. The filter assembly1can be suitable to filter liquid operating media of a vehicle, for example, fuels, such as diesel fuel, kerosene or gasoline. Preferably, the filter assembly1is used in motor vehicles, in particular in passenger cars, trucks, construction vehicles or agricultural machines, in watercraft, in rail vehicles or in aircraft. Moreover, the filter assembly1can be used, for example, in building technology. Preferably, the filter assembly1is a strainer assembly which is suitable to filter diesel fuel.

The filter assembly1comprises a filter element2. The filter element2is preferably a strainer element for filtering diesel fuel of an internal combustion engine, in particular of a diesel engine. The filter element2will be discussed in the following with reference toFIGS.4to6. The filter element2is received in a filter housing3. The filter housing3comprises a filter housing pot4in which the filter element2is arranged. The filter housing3can be part of a motor housing of the aforementioned internal combustion engine.

The filter housing pot4is preferably constructed substantially with rotational symmetry relative to a central axis or symmetry axis M. The filter housing pot4in the orientation ofFIGS.1to3is open in an upward direction and can be fluid-tightly closed off by means of a filter housing cover, not illustrated. The filter housing cover can be connected detachably to the filter housing pot4, for example, by means of a thread or a bayonet closure. The filter housing pot4comprises an outlet or drain, not illustrated, by means of which clean fluid purified by means of the filter element2, for example, filtered diesel fuel, can be discharged and, for example, supplied to a low pressure pump of a diesel injection system of the internal combustion engine.

The filter housing3comprises a receiving region5which is constructed as a stepped bore in the filter housing3. Raw fluid to be filtered, in particular diesel fuel to be filtered, is supplied to the receiving region5by means of an inlet or supply, not illustrated. A main flow path6of the raw fluid is oriented parallel to the symmetry axis M.

As illustrated inFIG.3, the receiving region5comprises, viewed in the direction of the main flow path6, a cylinder-shaped first section7; a valve seat8adjoining the first section7and curved spherically or curved in a ball shape; a truncated cone-shaped second section9adjoining the valve seat8; a cylinder-shaped third section adjoining the second section9; a truncated cone-shaped fourth section11adjoining the third section10; a cylinder-shaped fifth section12adjoining the fourth section11; as well as a truncated cone-shaped sixth section13adjoining the fifth section12. The sections10to13can extend in this context in a tubular shape into the filter housing pot4. A diameter of the sections7to13increases, viewed along the main flow path6, beginning at the first section7toward the sixth section13. At the third section10, moreover a drain channel14(FIGS.1and2) is provided.

In this context, that the valve seat8is “spherically” curved or curved in a ball shape, means that the valve seat8has the shape of a sphere segment that is cut out of a sphere by two parallel planes. This sphere segment is delimited by a transition of the first section7into the valve seat8and by a transition of the valve seat8into the second section9.

In the receiving region5, a spherical valve body15is received. The valve body can also be referred to as valve ball. The valve body15is matched to the valve seat8such that the valve body15rests areally on the valve seat8and can seal fluid-tightly relative thereto. The valve body15is manufactured, for example, of a plastic material. Preferably, the plastic material has a reduced density compared to the raw fluid so that the valve body15will not rise in the raw fluid. Preferably, the valve body is manufactured of polyamide (PA), in particular of polyamide 6 (PA 6). The valve body15can however be manufactured also of any other suitable material. The valve body15is in particular movable linearly within the sections9,10along the symmetry axis M, meaning in the direction of the main flow path6or opposite thereto.

Now returning to the filter element2shown inFIGS.4to6. The filter medium16is constructed preferably of rotational symmetry relative to the aforementioned symmetry axis M. The filter element2comprises a filter medium16. The filter medium16can be, for example, a plastic net with a mesh size of 500 μm to 200 μm, in particular of 300 μm. The filter medium16forms a cylinder surface which is constructed of rotational symmetry relative to the symmetry axis M.

The filter medium16however can also be or comprise, for example, a filter fabric, a laid filter material or a filter nonwoven. The filter medium16can be felted or needled. The filter medium16can comprise natural fibers such as cellulose or cotton, or plastic fibers, for example, of polyester, polyvinyl sulfide or polytetrafluoroethylene. Fibers of the filter medium16can be oriented during manufacture in a machine direction, slanted to the machine direction and/or transverse to the machine direction. The filter medium16can also be a filter body of flat and zigzag-folded filter material. In this case, the zigzag-shaped filter material forms the filter medium16as a star-shaped endless folded bellows which substantially forms a cylinder surface.

The filter medium16is supported from the exterior by a fluid-permeable support tube17. The support tube17can be embodied tubular. The support tube17can also be designed as a support structure or can be referred to as such. Preferably, the support tube17is grid-shaped. The support tube17can prevent collapse of the filter medium16. The support tube17can also be arranged inside the filter medium16. For example, the support tube17is injection-molded by a plastics injection molding method onto the filter medium16. The support tube17comprises a ring section18that extends circumferentially in an annular shape about the symmetry axis M. By means of the ring section18, a fluid-tight sealing action of the filter element2with respect to the filter housing3can be achieved.

From an end face19of the ring section18, two follower elements20,21are protruding. Preferably, the follower elements20,21are integrally formed as one piece, in particular monolithically, together with the ring section18. Here, “one piece” means that the ring section18and the follower elements20,21form together a common component. In this context, “monolithic” means that the ring section18and the follower elements20,21are manufactured throughout of the same material or substance.

The follower elements20,21can be part of a bayonet closure with which the filter element2can be connected with form fit to the aforementioned filter housing cover. For this purpose, at the filter housing cover corresponding follower counter elements are provided. A form fit connection is produced by the mutual engagement and engagement from behind of at least two connection partners, in this case of the follower elements20,21and the corresponding follower counter elements. Since the filter element2is coupled with the filter housing cover, the filter element2can be pulled out of the filter housing pot4when removing the filter housing cover from the filter housing pot4.

The filter medium16or the support tube17delimits an interior22of the filter element2. The interior22is cylinder-shaped and constructed of rotational symmetry to the symmetry axis M. The filter element2comprises moreover a valve body guide23for guiding the valve body15. The valve body guide23and the support tube17can be connected as one piece, in particular monolithically, by means of a disk-shaped connecting section24. This means that the valve body guide23can be part of the support tube17.

Alternatively (not shown), the valve body guide23can also be detachably connected to the filter element2, in particular detachably to the support tube17. In this case, the valve body guide23can be snapped on, clipped on, screwed onto the filter element2or connected in other ways in a form-fit and/or material-fused connection with the filter element2. Moreover, the valve body guide23can also be part of the filter housing3and, for example, detachably coupled thereto.

The valve body guide23is tubular and is substantially constructed of rotational symmetry relative to the symmetry axis M. The valve body guide23comprises a riser pipe25extending into the interior22of the filter element2as well as a coupling pipe26that is formed as one piece, in particular monolithically, together with the riser pipe and projects at the end face out of the connecting section24and that can be received in the receiving region5of the filter housing3. The riser pipe25and the coupling pipe26are constructed in this context with rotational symmetry relative to the symmetry axis M.

At the exterior side at the coupling pipe26, two circumferentially extending annular grooves27,28are provided in which two sealing elements29,30(FIGS.1and2), in particular O-rings, can be received. By means of the sealing elements29,30, the coupling pipe26is sealed relative to the receiving region5. Between the annular grooves27,28, an annular drain groove31is provided extending circumferentially about the coupling pipe26which, in a mounted state of the filter element2in the filter housing3, is in fluid communication with the drain channel14of the filter housing3(FIG.1).

The valve body guide23comprises moreover a fluid channel32extending through the entire valve body guide23, i.e., through the riser pipe25as well as through the coupling pipe26. The fluid channel32can have a circular cross section. Alternatively, the fluid channel32can also have any other arbitrary cross section. The fluid channel32has a diameter d32(FIG.6).

The fluid channel32comprises a longitudinal direction L. The longitudinal direction L is oriented parallel to the symmetry axis M or coincides therewith. In the orientation ofFIG.4, the longitudinal direction L is oriented from bottom to top. The longitudinal direction L can however also be oriented from top to bottom. Moreover, the fluid channel32has also correlated therewith a radial direction R. In this context, the radial direction R is oriented perpendicularly to the longitudinal direction L, respectively, perpendicularly to the symmetry axis M. In this context, the radial direction R is oriented away from the symmetry axis M in the direction of an inner wall of the fluid channel32.

The valve body guide23comprises a plurality of support ribs33to35which extend along the longitudinal direction L. Preferably, three such support ribs33to35are provided. In particular, at least two such support ribs33to35are provided. The valve body15can rest on the support ribs33to35. The support ribs33to35project in the radial direction R into the fluid channel32. The support ribs33to35do not extend however across the entire diameter d32of the fluid channel32.

Preferably, the support ribs33to35are uniformly distributed about a circumference of the fluid channel32. Each support rib33to35has correlated therewith a curved support surface36(FIG.6) for the valve body15. The support surface36in this context is preferably curved spherically or curved with a circular cylinder shape. This means that the respective support surface36is matched to an outer contour of the valve body15. In this way, a geometry or curvature of the support surface36is matched to a diameter d15of the valve body15. The support surfaces36of the support ribs33to35, the valve body15, and the valve seat8form a ball valve37(FIG.6), in particular a check valve, of the filter assembly1.

The coupling pipe26or the valve body guide23comprises an end face38(FIG.4) oriented in the direction toward the valve body15and from which trapezoidal guide sections39to41protrude. The guide sections39to41are arranged in this context uniformly distributed about a circumference of the valve body guide23. In this context, each support rib33to35has correlated therewith such a guide section39to41. The support ribs33to35extend in this context at least in sections thereof along the guide section39to41correlated with the respective support rib33to35. The support ribs33to35extend thus past the end face38. Between the guide sections39to41, intermediate spaces42(FIG.4) are provided through which the raw fluid can flow.

The filter element2comprises a raw side RO as well as a clean side RL. The raw side RO is correlated with the interior22. The clean side RL is outside of the filter medium16, i.e., arranged in an annular space provided between the filter medium16and the filter housing pot4. In operation of the filter assembly1, the raw fluid flows from the raw side RO through the filter medium16to the clean side RL whereby contaminants are retained by the filter medium16and remain in the interior22.

The ball valve37can be moved by means of the raw fluid flowing in the direction of the main flow path6from a closed state Z1(FIG.2), in which the valve body15is resting seal-tightly on the valve seat8, into an open state Z2(FIG.1), in which the valve body15is lifted off the valve seat8and is resting on the support surfaces36of the support ribs33to35. As soon as no raw fluid flows along the main flow path6anymore, the valve body15sinks and seals again fluid-tightly relative to the valve seat8. In this way, it can be reliably prevented that air reaches a fuel line which is connected to the receiving region5. In this way, it is prevented that the low pressure pump positioned downstream of the valve assembly1will suck in air after an exchange of the filter element2.

Since the support ribs33to35are provided, a defined position of the valve body15is ensured in the open state Z2of the ball valve37. A flow cross section extending about the valve body15for the raw fluid is only insignificantly restricted by the support ribs33to35. An undesirable rotation and thus wear of the valve body15can be prevented in a reliable manner by the defined position thereof and by preventing an increase of the flow rate of the raw fluid due to only a minimal restriction of the aforementioned flow cross section.

Moreover, a faulty assembly of the valve body15is prevented. The valve body15, even when its diameter d15is smaller than the diameter d32of the fluid channel32, cannot be inserted in the orientation ofFIGS.4to6from above into the valve body guide23. This is so because the support ribs33to35project so far into the fluid channel32that the valve body15is resting thereon. The support ribs33to35prevent thus reliably faulty installation of the valve body15. In particular, a so-called error-avoiding poka-yoke principle can be realized in this way.

For exchange of the filter element2, the latter is pulled out of the filter housing pot4, as illustrated inFIG.2(partially pulled out) andFIG.3. In this context, clean fluid contained in the filter housing pot4can drain through the drain channel14. The riser pipe25prevents in this context that contaminants collected in the interior22can reach the receiving region5.

LIST OF REFERENCE CHARACTERS

1filter assembly2filter element3filter housing4filter housing pot5receiving region6main flow path7section8valve seat9section10section11section12section13section14drain channel15valve body16filter medium/screen fabric17support tube18annular section19end face20follower element21follower element22interior23valve body guide24connecting section25riser pipe26coupling pipe27annular groove28annular groove29sealing element30sealing element31drain groove32fluid channel33support rib34support rib35support rib36support surface37ball valve38end face39guide section40guide section41guide section42intermediate spaced15diameterd32diameterL longitudinal directionM symmetry axisR radial directionRL clean sideRO raw sideZ1closed stateZ2open state