DE102018114374A1 - Fluid filter with two superposed filter elements and a flow guide device - Google Patents

Abstract

The invention relates to a fluid filter (10) comprising a filter housing (12), two longitudinally superposed filter elements (20, 22) and a flow guide unit (38). The flow guidance unit (38) has at least three disc elements (40a-d) which are arranged spaced apart in the axial direction between the two filter elements (20, 22). In each case a flow channel (42a-c) is formed between the disk elements (40a-d), which is immediately delimited by two of the disk elements (40a-d) in the axial direction. The flow guidance device (38) has at least one axial inlet (44a-c) for each of the flow channels (42a-c), via which in each case an interior (46a, 46b) of one of the filter elements (20, 22) with the associated flow channel (42a-c). 42a-c) is fluidly connected. The flow channels (42a-c) are fluidically connected to a respective side wall connection (48a-c) of the filter housing (12). The invention also relates to a flow guiding device (38) for such a fluid filter (10).

Description

Technical area

The invention relates to a fluid filter, in particular for fuel or oil, comprising a filter housing, two filter elements, which are arranged one above the other in the filter housing in an axial direction to the longitudinal axis of the filter housing, and a flow guiding device. The invention further relates to a flow guidance device for a fluid filter.

State of the art

EP 0 276 795 A2 discloses a fluid filter having at least two equiaxed filter elements which can be flowed through in the axial direction, wherein a gap is formed between the filter elements by sieves. Through the intermediate space, fluid to be filtered can flow to the filter elements connected fluidically in parallel, or filtered fluid can be removed from the fluidically connected filter elements. Out US 4,869,820 a well-structured oil filter has become known.

In US 4,792,397 a fluid filter is described in which a fluid collector between two fluidically connected in parallel, one above the other and arranged in the axial direction through which filter elements is arranged. The fluid collector has a substantially flat portion which is perforated by holes and from which ridges project on both sides in the axial direction towards the filter elements. The ribs are arranged in a circle segment on the flat section, so that passage paths for the filtered fluid are arranged between the ribs. The passageways of the fluid collector open radially inwardly into receiving openings of a central flow tube.

The known fluid filters have a complex structure with partly long flow paths with small flow cross sections. In particular, they require a lot of space in the axial direction. They also do not allow serial flow through the filter elements.

The object of the invention is therefore to provide a fluid filter with two filter elements and a flow guidance device for such a fluid filter, which allow a more compact and simpler structural design of the fluid filter.

Disclosure of the invention

The object relating to the fluid filter is achieved by a fluid filter having the features specified in claim 1. The flow guide device according to the invention has the features specified in claim 14. Further developments of the invention are described in the description and the dependent claims.

The fluid filter according to the invention can be designed in particular for filtering fuel or oil, for example for the internal combustion engine of a motor vehicle. The fluid filter comprises a filter housing. In the filter housing two filter elements are arranged one above the other in a direction axial to the longitudinal axis of the filter housing. According to the invention, the fluid filter has a flow guidance device with at least three disc elements. The at least three disc elements are arranged spaced apart in the axial direction between the two filter elements. In other words, one of the filter elements above the disc elements of the flow guiding device is arranged in the filter housing and the other filter element is arranged below the disc elements in the filter housing. The disc elements are therefore in the range of the axial distance between the two filter elements. According to the invention, a flow channel is formed in each case between the disk elements and is directly delimited by in each case two of the disk elements in the axial direction. Consequently, at least two flow channels are formed in the flow guiding device. Each flow channel is immediately bounded by two adjacent disk elements. An axially inner disk element defines on the upper side a lower of the flow channels and on the underside an upper flow channel. Overall, the at least two flow channels can thereby be set up in a particularly space-saving manner and tightly one above the other in the fluid filter. The flow guiding device according to the invention has at least one axial inlet for each of the flow channels. In each case an interior of one of the filter elements is fluidically connected to the associated flow channel via the axial inlet. The interior of a filter element may form a raw side or, preferably, a clean side of the respective filter element. A flow path between the interior and the flow channel is opened in each case via the axial inlet. Fluid can thus flow from one of the internal spaces through the associated axial inlet into the associated flow channel or out of the flow channel through the axial inlet into the interior space. An axial inlet can be formed for example by a, in particular central, recess or an annular gap in the respective disc element. By the flow guiding device of the fluid filter according to the invention, a plurality of fluid streams can be discharged close to each other from the fluid filter. The fluid streams may in particular be the filtrates of the two filter elements. The flow channels allow a derivation of the fluid streams the fluid filter in the radial direction. The flow channels are each fluidly connected to a side wall connection of the filter housing.

The side wall connections can be arranged in the axial direction one above the other or distributed in the circumferential direction on the side wall of the filter housing. On the side wall connections can be connected in a simple manner and space-saving fluid lines. The sidewall connections can each have a connection piece. Corresponding lines can be positioned close to one another on the filter housing without having to carry out additional channels in the filter housing or in a filter insert carrying the two filter elements. By the flow channels in the flow guiding device particularly short flow paths can be realized. This reduces the pressure loss and saves costs. Furthermore, there are advantages in the utilization of an available (one) installation space, since the fluid filter according to the invention can be made very compact.

According to the invention, a ring nozzle can extend away from one of the disc elements in the axial direction and limit at least one of the aforementioned axial inlets with. This simplifies the guiding of the fluid streams. The annular nozzle can thereby extend through a recess in another of the disc elements. The annular nozzle may be formed for a sealing engagement with the recess provided with the disc element.

According to a preferred embodiment of the invention, at least one of the axial inlets is formed as an annular gap between the annular nozzle and one of the disc elements. As a result, a particularly compact flow guidance is created. Also, the annular nozzle can form an axial inlet in the radial direction with the fluid channel enclosed by it. This allows axial passage of a fluid flow through at least one of the disk elements.

The flow guide device is preferably formed integrally for cost reasons and under production engineering aspects. In this case, the flow guiding device can be inexpensively designed as a plastic injection-molded part.

According to the invention, at least one of the two filter elements or both filter elements can each be designed as a round filter element which can be radially flowed through from the outside to the inside. The round filter element may have a star-shaped folded filter medium with regard to a large functional filter surface.

By means of the flow guiding device, the filtered fluid flowing out of the respective filter element can be discharged radially outward from the fluid filter via the flow channels, in each case from the interior of the filter elements arranged on the clean side (fluidically behind the filter medium). Elaborate to be manufactured additional channels in the filter housing unnecessary.

The fluid filter or one of the two filter elements can furthermore have a water separation unit for separating water contained in the fluid. Since the separated in the Wasserabscheideeinheit water is able to settle gravity, the Wasserabscheideeinrichtung is preferably associated with the arranged in the axial direction overhead filter element from a design point of view. In this case, the water separation unit can be fluidly connected on the output side to one of the flow channels formed by the flow guidance device. As a result, the water separated from the fluid can be led out of the fluid filter in the radial direction. The Wasserabscheideeinheit may in particular a coalescer, designed as a calmed flow zone Wasserabscheidespalt and / or a Endabscheidesieb. The coalescer can be arranged fluidically upstream or downstream of the filter medium of the respective filter element. A multilayer structure of the coalescer is conceivable. Preferably, the Wasserabscheideeinheit is assigned to a serving as a pre-filter element filter element, so that a pre-and serving as the main filter element filter element fluidly interposed (fluid) pump is protected against corrosion damage.

The flow guiding device according to the invention can have four disk elements with three flow channels, which are directly bounded by the disk elements. In this case, both filter elements and additionally also the above-described water separation unit can be fluidly connected on the output side to one of the (radially extending) flow channels of the flow guidance device and drained via the side wall connections.

According to the invention, the two filter elements, in particular their filter media, in each case with the axially outwardly arranged disk elements of the flow guide means non-positively or cohesively connected, in particular glued or welded to these. Due to the non-positive or cohesive connection, the axially outer disc elements can also serve as known per se end plates for the filter elements. This offers cost advantages and allows a particularly simple assembly, because the filter elements can be used with the flow guide device as a one-piece unit in the filter housing and removed from this. If both filter elements have independent end disks at their end disks facing each other, then the filter elements can be mechanically coupled to one another via the flow guidance device. The filter elements can be attached to the flow guide device, for example by a latching, plug or bayonet connection, so that an easy to handle (construction) unit is formed.

Particularly preferably, the disk elements of the flow guiding device are in each case sealingly against the filter housing on the inside. The filter housing can thereby be divided into a prefilter chamber and a main filter chamber. An undesirable bypass wall bypassing the housing wall, in particular of unfiltered fluid between the filter housing and the disk elements, can thereby be counteracted. Cross contamination of the two filter chambers can be reliably avoided. The disk elements may in this respect be circumferentially provided in each case with an annular sealing element. For this purpose, a seal holding structure, for example in the form of a retaining groove, for the annular sealing element is preferably formed on the respective disk element.

Advantageously, the filter housing has a filter pot with a gradually tapering from an insertion opening of the filter housing in the direction of its housing bottom inner diameter. The filter elements and the flow guiding device can thereby be inserted in a simple manner from the insertion opening into the filter pot. By appropriate advancement, a sealing seat of the disc elements and possibly of end plates of the filter elements can be achieved on the filter housing.

Preferably, one of the filter elements is designed as a prefilter element and the other filter element as a main filter element, wherein the prefilter element is connected upstream of the main filter element. Due to the two-stage filtration, a particularly good cleaning effect with low pressure loss and high volume flows can be achieved. The prefilter element and the main filter element may differ from one another, in particular with regard to the filter surface, the material or the pore width of their filter medium (filter material). During the operation of the fluid filter, prefiltered fluid preferably flows out of the prefilter element into one of the flow channels and is conveyed out of this flow channel into the main filter element by a pump, which is arranged outside the fluid filter. Fluid filtered by the main filter element is removed from the filter housing via another of the flow channels.

The scope of the present invention also includes a flow-guiding device for a fluid filter according to the invention.

The flow guiding device according to the invention enables a particularly space-saving discharge or introduction of a plurality of fluid streams out of / into the filter housing of the fluid filter in a direction radial to the longitudinal axis of the fluid filter.

list of figures

• 1 einen erfindungsgemäßen Fluidfilter, umfassend eine Strömungsführungseinrichtung mit drei übereinander angeordneten Scheibenelementen, die zwei Strömungskanäle begrenzen, in einem Längsschnitt;
• 2a die erfindungsgemäße Strömungsführungseinrichtung des Fluidfilters gemäß 1 in einem freigestellten Längsschnitt;
• 2b die Strömungsführungseinrichtung gemäß 2a in perspektivischer Ansicht;
• 3 einen weiteren erfindungsgemäßen Fluidfilter, umfassend eine Strömungsführungseinrichtung mit vier Scheibenelementen, die drei Strömungskanäle begrenzen, in einem Längsschnitt;
• 4a die erfindungsgemäße Strömungsführungseinrichtung des Fluidfilters von 3 in einem Längsschnitt; und
• 4b die Strömungsführungseinrichtung von 4a in perspektivischer Ansicht.

In the drawing show:

• 1 a fluid filter according to the invention, comprising a flow guide device with three disk elements arranged one above the other, which delimit two flow channels, in a longitudinal section;
• 2a the flow guidance device according to the invention of the fluid filter according to 1 in an exempted longitudinal section;
• 2 B the flow guide device according to 2a in perspective view;
• 3 a further fluid filter according to the invention, comprising a flow guide device with four disc elements which define three flow channels, in a longitudinal section;
• 4a the flow guidance device according to the invention of the fluid filter of 3 in a longitudinal section; and
• 4b the flow guiding device of 4a in perspective view.

Embodiments of the invention

1 shows a fluid filter according to the invention 10 for a fluid to be filtered, in particular fuel or oil, in a longitudinal section. The fluid filter 10 includes a filter housing 12 with a filter pot 14 with an insertion opening 16 passing through a housing cover 18 is closed. The housing cover 18 can in the filter pot 16 screwed in or otherwise on the filter pot 16 be attached.

Inside the filter housing 12 are a first filter element 20 and a second filter element 22 arranged, which are serially flowed through by the fluid to be filtered. The filter elements 20 . 22 are in one to the longitudinal axis 24 of the fluid filter 10 Axial direction arranged one above the other and thereby spaced from each other. The two filter elements 20 . 22 each have a filter medium 26 on. The Filtermediem can each be folded in a star shape and the longitudinal axis 24 encircle annularly. The filter media 26 the two filter elements 20 . 22 are here by way of example in each case in a radial direction from the outside to the inside flowed through. It is understood that the filter media 26 the two filter elements 20 . 22 in their material properties, their pore size or their active filter surface can differ from each other. To support the filter media 26 can each have a grid-shaped support tube 28 serve.

The fluid filter 10 here has an integrated Wasserabscheideeinheit 30 on. The water separation unit 30 Here is an example of the second filter element 22 assigned.

The water separation unit 30 can be a coalescing medium 32 and / or a final separation screen 34 include. The coalescer medium 32 can the filter medium 26 of the second filter element 22 according to 1 arranged downstream of the fluid and in particular radially on the inside of the support tube 28 be supported. It goes without saying that the Koalszermedium 32 can be multi-layered. Between the support tube 28 and the Endabscheidesieb 34 can be a water separation gap 36 be formed, which allows, as a calmed flow zone, a gravity-induced settling of water droplets deposited from the fluid axially downwards.

The fluid filter 10 according to 1 a special flow guide device 38 on.

The flow guide device 38 includes three disc elements 40a . 40b . 40c , The disc elements 40a-c are in the axial direction (relative to the longitudinal axis 24 ) spaced from each other. Between two adjacent disc elements 40a-c each is a flow channel 42a . 42b educated. The flow channels 42a , B are each in the axial direction directly by each two of the disc elements 40a-c limited. The lower flow channel 42a is lower side by the first disc element 40a and on the upper side by the second disc element 40b limited. The flow channel 42b is lower side by the second disc element 40b and on the upper side by the third disc element 40c limited.

The flow guiding device has for each of the flow channels 42a . 42b an axial inlet 44a . 44b on, each one of the disc elements 40a . 40c be upheld. Through the axial inlets 44a . 44b is a respective flow channel 42a . 42b with a clean side (ie the respective filter medium fluidly downstream) arranged interior 46a . 46b a respective associated filter element 20 . 22 fluidly connected. Every flow channel 42a . 42b is with a sidewall connection 48a . 48b of the filter housing 12 fluidly connected. The axial inlets 44a . 44b allow fluid to flow in an axial direction into the flow channels 42a . 42b in which the fluid can then be forwarded in the radial direction. A reverse flow direction of the flow channels 42a . 42b or the axial inlets 44a . 44b is with appropriately designed filter elements 20 . 22 conceivable. The axial inlets 44a . 44b can each be designed as an annular gap with regard to the lowest possible flow resistance.

The flow guide device 38 can according to 1 a ring neck 50 respectively. The ring neck 50 extends here starting from the middle disc element 40b in the axial direction up and down away. The ring neck 50 forms a radially inner boundary of the annular gap. The sleeve-shaped Endabscheidesieb 34 the Wasserabscheideeinheit 30 sits on the ring neck 50 sealingly in the axial direction.

It should be noted that the flow guide device 38 in one piece, for example as a plastic injection molded part may be formed.

The filter pot 14 has a from an insertion 16 axially in the direction of its housing bottom 52 gradually tapering inside diameter 54 on. The disc elements 40a . 40b . 40c have circumferentially in each case an annular sealing element 56 , here in the form of an O-ring. The ring sealing element 56 can each in a holding groove (see also 2a . 2 B) the associated disc element 40a . 40b . 40c be held. The disc elements 40a . 40b . 40c lie with their ring sealing elements 56 on the filter pot 14 of the filter housing 12 inside sealing. The filter housing 12 is characterized on the inside in a first and a second filter chamber 58 . 60 divided.

The filter housing 12 points for the two filter elements 20 . 22 or filter chambers 58 . 60 here in each case a lateral fluid inlet 62 . 64 on. It is understood that the fluid inlet 62 of the first filter element 20 also at another position, for example on the bottom side of the filter housing pot 14 , can be trained.

It should be noted that the in 1 embodiment shown, the lower filter element 20 is designed as a prefilter element and the second filter element as a main filter element. During operation of the fluid filter 10 Thus, the fluid to be filtered first flows over the lower fluid inlet 62 to the first filter element functioning as a prefilter element 20 , After flowing through the first filter element 20 the fluid passes over the first axial inlet 44a in the first flow channel 42a the flow guide device 38 and flows in the radial direction over the associated side wall connection 48a of the filter housing 12 from the fluid filter 10 out.

From the sidewall connection 48a For example, the fluid may be delivered to the second fluid inlet by means of a pump (not shown) 64 of the filter housing 12 be encouraged. The fluid then flows through the second filter element formed as the main filter element 22 , The water separation gap 36 is here via the second axial inlet with the second flow channel 42b fluidly connected. From the fluid separated water can thereby from the second sidewall port 48b from the fluid filter 10 be discharged in the radial direction.

The at least partially released fluid from the water passes through the Endabscheidesieb 34 the Wasserabscheideeineit 30 in the interior 46b of the second filter element 22 and gets over one through the ring neck 50 encompassed fluid channel 66 in the axial direction down a bottom-side fluid outlet 68 of the filter housing 12 fed.

The filter elements 20 . 22 can at the flow guide device 38 be attached cohesively or non-positively. In the embodiment shown, the filter media 26 the two filter elements 20 . 22 each end face with the disc elements 40a or. 40c glued or in the material of the disc elements 40a or. 40c kept embedded. These disc elements thereby also form so-called end discs of the filter elements 22 . 24 , This dual function offers cost advantages.

The fluid filter 10 If necessary, one with 70 Have designated ventilation device. The filter pot 14 If necessary, an idle channel 72 in the filter operation, preferably indirectly or directly through the first filter element 20 is sealed fluid-tight.

The flow guide device 18 of the fluid filter according to 1 is in 2a in an isolated longitudinal section and in 2 B shown in a detached perspective view. From the ring neck 50 cantilevers in the radial direction the middle disc element 40b out. The disc element 40b is in the circumferential direction with the ring nozzle 30 in full contact. At the middle disc element 40b are according to 2 B over spacers 74 the two axially outboard disc elements 40a . 40c attached. The spacer elements 74 may be formed for manufacturing reasons as mutually parallel ribs. The outer disc elements 40a . 40c do not reach in the radial direction to the ring neck 50 zoom in between the disc elements 40a . 40c and the ring neck 50 in each case the axial inlets 44a . 44b the two disc elements 40a . 40c form as circumferential annular gaps.

3 shows a further fluid filter 10 which is different from the one mentioned above 1 to 2 explained fluid filter 10 essentially differs in that the flow guide device 38 a total of four disc elements 40a . 40b . 40c . 40d having. The flow guide device 38 has consequently three flow channels 42a . 42b . 42c on, each in a sidewall connection 48a . 48b . 48c of the filter housing 12 lead.

The final separator sieve 34 the Wasserabscheideeinheit 30 sits sealingly on a ring neck 50 the flow guide device 18 on. The water separation unit 30 of the second filter element 22 here indicates the filter medium 26 fluidly arranged downstream Koalsezermedium 32 on. The coalescer medium 32 is between a first and a second support tube 28 kept arranged. Between the ring neck 50 and the axially uppermost fourth disc element 40d is an axial inlet 44c for the flow channel 42c furnished in the form of an annular gap. The axial inlet 44c is in fluid communication with the water separation gap 36 the Waserabscheideeinheit 30 of the second filter element 22 ,

The through the ring neck 50 in the radial direction on the outside limited fluid channel 66 forms the axial inlet 44b to the radially extending (middle) second flow channel 42b , Via the fluid channel 66 , Flow channel 42b as well as the sidewall connection 48b may be the filtered fluid from the second filter element 22 be derived.

The filter element 22 is here exemplified as a main filter element. The axially lowest disc element 40a here has a centrally located axial inlet 44a to the second flow channel 42a on. The interior 46a of the first filter element 20 is above the axial inlet 44a in fluid communication with the first flow channel 42a ,

The flow guide device 38 of the fluid filter 10 according to 3 is in 4a in an isolated longitudinal section and in 4b shown in a perspective view. The ring neck 50 extends from the disk element 40c in the direction of the longitudinal axis 24 up through the top disc element 40d through and over the top disc element 40d in the axial direction. Between the ring neck 50 and the top disc element 40d is a third axial inlet 44c for the flow channel 42c formed, which is designed here as an annular gap. The disc element 40b is continuously closed (without continuous recesses in the axial direction) designed to the flow channels 42a and 42b fluidly separated from each other. The flow guide device 38 is also executed here in one piece. The disc elements are about spacers 74 supported on each other.

It is understood that in each case the first or the second filter element 20 . 22 as a prefilter element and the respective other filter element may be formed as a fluidic downstream main filter element.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0276795 A2 [0002]
• US 4869820 [0002]
• US 4792397 [0003]

Claims (14)

Fluid filter (10), in particular for fuel or oil, comprising - A filter housing (12); - Two filter elements (20, 22) which are arranged in the filter housing (12) in an axial direction to the longitudinal axis (24) of the fluid filter superimposed; and - A flow guide means (38) having at least three disc elements (40a-d), which are spaced apart in the axial direction between the two filter elements (20, 22), wherein between the disc elements (40a-d) each have a flow channel (42a-c ), which is directly delimited by in each case two of the disk elements (40a-d) in the axial direction, and wherein the flow guidance device (38) has at least one axial inlet (44a-c) for each of the flow channels (42a-c), via each of which an interior space (46a, 46b) of one of the filter elements (20, 22) is fluidically connected to the associated flow channel (42a-c), the flow channels (42a-c) each having a side wall connection (48a-c) of the filter housing (12) are fluidly connected. Fluid filter after Claim 1 , characterized in that a ring nozzle (50) of one of the disc elements (40a-d) extends away in the axial direction and at least one of the axial inlets (44a-c) with limited. Fluid filter after Claim 2 , characterized in that at least one of the axial inlets (44a-c) is formed as an annular gap between the annular nozzle (50) and one of the disc elements (40a-d). Fluid filter after Claim 2 or 3 , characterized in that one of the axial inlets (44a-c) is formed by a fluid channel (66) delimited in the radial direction by the annular stub (50). Fluid filter according to one of the preceding claims, characterized in that the flow guiding means (38) are integrally formed, preferably as a plastic injection molded part. Fluid filter according to one of the preceding claims, characterized in that the two filter elements (20, 22) or at least one of the two filter elements (20, 22) as a radially from outside to flow through the round filter element, in particular with a star-shaped folded filter medium (26) formed are / is. Fluid filter after Claim 6 , characterized in that one of the two filter elements (20, 22) has a Wasserabscheideeinheit (30). Fluid filter after Claim 7 , characterized in that the Wasserabscheideeinheit (30) on the output side in one of the flow channels (42 a-c) of the flow guidance device (38) opens. Fluid filter according to one of the preceding claims, characterized in that the flow guiding device (38) has four disc elements (40a-d) with three flow channels (42 ac). A fluid filter according to one of the preceding claims, characterized in that the two filter elements (20, 22) are frictionally or cohesively connected to the disk elements (40a-d) of the flow guiding device (38) which are arranged on the outside in the axial direction, in particular glued or welded thereto are. Fluid filter according to one of the preceding claims, characterized in that the disc elements (40a-d) of the flow guiding device (38) in each case abut sealingly on the filter housing (12) on the inside. Fluid filter according to one of the preceding claims, characterized in that the filter housing (12) has a filter bowl (14) with a from an insertion opening (16) of the filter housing (12) in the direction of its housing bottom (52) gradually tapered inner diameter (54). Fluid filter according to one of the preceding claims, characterized in that one of the filter elements (20, 22) as a prefilter element and the other filter element (20, 22) is designed as a main filter element, wherein the prefilter element is fluidly connected upstream of the main filter element. Flow guiding device (38) for a fluid filter (10) according to one of the preceding claims.

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