DE112014005675B4 - Multi-stage water-separating filter element with bayonet connection and fuel filter with such a filter element - Google Patents

Abstract

Filter element (12, 42, 86, 124, 138) for a fuel filter (10, 84, 122) of a motor vehicle, the filter element (12, 42, 86, 124, 138) in a filter housing (14, 88) of the fuel filter ( 10, 84, 122) can be used and the filter element (12, 42, 86, 124, 138) for the multi-stage cleaning of a fuel has a particle filter medium (58), a coalescing medium (66), a sedimentation gap (64, 98) and a final separator sieve ( 70), wherein the filter element (12, 42, 86, 124, 138) furthermore has a bayonet projection (44, 46, 48, 112, 144, 146, 148) which is used for engaging behind a bayonet receptacle (114) in a cover ( 18, 106, 130) of the filter housing (14, 88), in which the filter element (12, 42, 86, 124, 138) has a double seal (34, 76) towards the filter housing (14, 88), which in particular is arranged on an end plate (60) of the filter element (12, 42, 86, 124, 138), which preferably in the installed position of the filter element (12, 42, 86, 124, 138) below a is arranged.

Description

Technical area

The invention relates to a filter element for a fuel filter of a motor vehicle. The invention also relates to a fuel filter with such a filter element.

State of the art

A filter element for filtering fuel of a motor vehicle is from the DE 10 2011 078 362 A1 known. The filter element has a particle filter medium and a final separator screen for separating water. The separated water collects in a water collection room.

From the EP 1 356 199 B1 Vent nozzles for a liquid filter have become known.

The US 2009/0301950 A1 discloses a filter element which can be fastened to the cover of a filter housing by means of a bayonet catch.

Also the EP 2 201 993 A1 discloses attaching a replaceable filter element to a pot of a filter housing by a bayonet lock.

After all, from the US 2011/0017657 A1 various sealing options of a filter element to a channel of a filter housing have become known.

Out US 2010/101 993 A1 discloses a filter within a filter system that includes a sealing structure on an end plate of an outer filter element. The sealing structure seals an annular flange on the end plate when the filter cartridge is assembled for use.

EP 2 135 661 A2 describes a liquid filter apparatus and method for ensuring that a correct filter element is installed in a filter housing.

WO 2013/083 705 A1 Fig. 10 shows a filter element of a fuel filter and a method for manufacturing the same. At least one tubular filter medium is tightly connected to an end body at least on one end face. At least one support tube coaxial with the filter medium is connected to the end body at one end.

As a result of the greatly increased expectations of the performance of internal combustion engines in motor vehicles, the requirements for the purity and freedom from water of the fuel for use in internal combustion engines have risen sharply. The fuel filters used to clean the fuel in the motor vehicle must therefore have several cleaning stages, in particular several water separation stages, for cleaning the fuel. The known multi-stage water-separating filter elements are, however, relatively unfriendly to maintenance due to their design. In particular, the removal of a filter element to be changed from a filter housing is complex, since the filter element to be changed is usually completely sunk into the filter housing.

Disclosure of the invention

The invention is therefore based on the object of providing a multi-stage water-separating filter element and a fuel filter with such a filter element, which are designed to be particularly easy to maintain.

This object is achieved by a filter element with the features of claim 1 and by a fuel filter with the features of claim 5. The subclaims indicate expedient developments of the invention.

The object according to the invention is thus achieved by a filter element for a fuel filter of a motor vehicle, wherein the filter element can be inserted into a filter housing of the fuel filter and the filter element for multi-stage cleaning of a fuel has a particle filter medium, a coalescing medium, a sedimentation gap and a final separator screen, the filter element also having has a bayonet projection which is designed to engage behind a bayonet receptacle in a cover of the filter housing.

The fuel is cleaned in several stages by the filter element. The particle filter medium separates particles in the fuel. Subsequently, i.e. on the clean side, a multi-stage water separation takes place. At first, larger water droplets are formed in the coalescing medium from fine water droplets. These water droplets sink into the sedimentation gap. Finally, the final separator screen acts as a baffle plate to separate the water in the fuel again.

If the filter element is replaced, a cover of the filter housing in which the filter element is arranged is unscrewed. When the cover is unscrewed, the bayonet projection of the filter element engages behind the bayonet receptacle in the cover of the filter housing. The filter element can then be removed together with the cover. In other words, the lid of the Filter housing as a handle for dismantling the filter element. The filter element according to the invention is thus designed to be particularly easy to maintain.

The filter element can have a plurality of bayonet projections which are designed to engage in respective bayonet receptacles in the cover of the filter housing. In other words, the bayonet projections are designed for engaging behind bayonet receptacles on the inside of the cover. As a result, the filter element can be held particularly securely in the cover. The bayonet projections are preferably designed to be axially symmetrical to the longitudinal axis of the filter element.

A filter element that is particularly simple in construction and can thus be produced at low cost is obtained if the particle filter medium is arranged between a first end plate and a second end plate of the filter element. The coalescing medium, in particular also the final separating screen, is preferably also arranged between the two end plates.

The filter element preferably has a ventilation pipe running along the longitudinal axis of the filter element. Air in the filter system can be discharged through the ventilation pipe. The ventilation tube can be designed in the form of a support tube which protrudes beyond at least one end disk of the filter element in the direction of the filter element longitudinal axis. This results in an additional stiffening of the filter element while at the same time making contact with the ventilation pipe in a simple manner.

The filter element has a double seal towards the filter housing. A double seal is understood to mean at least two seals, for example O-ring seals and / or molded seals for separating the clean side and the raw side of the filter element in the filter housing. A first seal of the double seal is preferably designed or arranged offset in the longitudinal direction of the filter element relative to a second seal of the double seal. In particular, the double seal is arranged on an end plate of the filter element, which is preferably arranged at the bottom in the installed position of the filter element.

In a preferred embodiment, the double seal is designed in such a way that when the filter element is mounted in a filter housing, an area can be sealed between the two seals in which z. B. opens a drainage channel of the filter system. The seals are preferably arranged in such a way that the area to be sealed forms an annular space around a (lower) end plate of the filter element.

Preferably, the two seals of the double seal can each have a circumferential, radially outwardly directed sealing surface which is used for sealing contact with a radially inwardly directed housing inner wall. The radially outwardly directed sealing surfaces are preferably axially offset from one another. Alternatively or in addition, the radially outwardly directed sealing surfaces are arranged at least almost coaxially to one another and / or have at least almost the same diameter in diameter. The size of the diameter of the radially outwardly directed sealing surfaces at least largely corresponds to the size of the outer circumference of the associated end plate and / or of the particle filter medium.

The filter element is preferably designed to be axially symmetrical to the longitudinal axis of the filter element for a simple and stable structure at the same time. In this case, the filter element, viewed in the radial direction from the longitudinal axis of the filter element, initially has a ventilation pipe which is surrounded by the final separator screen. The rotationally symmetrical sedimentation gap preferably adjoins the final separator sieve. The sedimentation gap is preferably delimited radially outward by a support body of the filter element. The coalescing medium and the particle filter medium are preferably supported on the outer jacket surface of the support body. The coalescing medium is preferably designed in the form of a fleece. The particle filter medium is preferably folded in a star shape.

The object according to the invention is also achieved by a fuel filter with a filter housing and a filter element described above, the filter housing having a cover which can be screwed onto a filter housing body and the cover has a bayonet receptacle on the inside, which is designed such that the bayonet projection into the bayonet receptacle engages when the cover is unscrewed from the filter housing body.

The fuel filter preferably has a filter element with a plurality of bayonet projections which are designed to each engage behind a bayonet receptacle in the cover of the fuel filter when the cover is unscrewed from the filter housing.

The fuel filter can have a check valve at one end on the ventilation pipe, which check valve is designed in such a way that it blocks in the event of a flow interruption. As a result, when the internal combustion engine is switched off, for example in the so-called start / stop mode, the fuel is kept in the fuel filter and prevents air present in a tank return from entering the tank via the fuel filter Internal combustion engine arrives. When the combustion engine is started, the fuel pressure required to enable ignition can be built up immediately in the fuel filter. The check valve thus enables short engine start times, which is particularly desirable in start / stop operation.

The check valve is preferably fastened in the fuel filter with a snap connection, in particular in a fluid-tight manner. As a result, the check valve can be installed particularly inexpensively.

In a particularly preferred embodiment of the invention, the check valve is fastened in the cover of the filter housing. When changing the filter element, the check valve does not have to be replaced in this case, which avoids waste and reduces maintenance costs.

The filter housing can have a drainage channel for a drainage of fuel which is accumulated on the raw side when the filter element is removed from the filter housing.

This avoids contamination of the fuel on the clean side of the fuel filter when changing the filter.

The drainage channel is preferably arranged or designed in such a way that when the filter element is removed from the filter housing, a first seal of the double seal seals the connection between the filter element and the filter housing on the clean side of the fuel filter for longer than a second seal the connection between the filter element and the drainage channel on a raw side the fuel filter. As a result, when the filter element hanging on the cover is pulled out of the filter housing, the connection between the raw side of the fuel filter and the drainage channel is first released so that the fuel can flow away from the raw side of the fuel filter via the drainage channel. Only then is the fluidic connection between the filter element and the filter housing at the first seal released by further pulling out the filter element. In this way, an unfiltered transfer of fuel from the raw side to the clean side is reliably avoided.

Figure list

Further features and advantages of the invention emerge from the following detailed description of several exemplary embodiments of the invention, with reference to the figures of the drawing, which shows details essential to the invention, and from the claims.

• 1 einen Längsschnitt durch einen ersten Kraftstofffilter mit einem ersten Filterelement;
• 2 einen Längsschnitt durch das erste Filterelement aus 1;
• 3 eine perspektivische Ansicht eines zweiten Filterelements für einen zweiten Kraftstofffilter (nicht dargestellt);
• 4 eine perspektivische Darstellung eines Längsschnitts des zweiten Filterelements aus 3;
• 5 eine Draufsicht auf einen weiteren Längsschnitt des zweiten Filterelements aus 3;
• 6 einen Längsschnitt durch einen dritten Kraftstofffilter mit einem dritten Filterelement;
• 7 einen Längsschnitt durch einen vierten Kraftstofffilter mit einem vierten Filterelement;
• 8 einen Längsschnitt durch ein fünftes Filterelement;
• 9 eine Draufsicht auf das fünfte Filterelement aus 8; und
• 10 eine geschnittene Teilansicht des Bereiches X des fünften Filterelements aus 8.

The features shown in the drawing are shown in such a way that the special features according to the invention can be made clearly visible. The various features can each be implemented individually or collectively in any combination in the case of variants of the invention. Show it:

• 1 a longitudinal section through a first fuel filter with a first filter element;
• 2 a longitudinal section through the first filter element 1 ;
• 3 a perspective view of a second filter element for a second fuel filter (not shown);
• 4th a perspective view of a longitudinal section of the second filter element 3 ;
• 5 a plan view of a further longitudinal section of the second filter element 3 ;
• 6th a longitudinal section through a third fuel filter with a third filter element;
• 7th a longitudinal section through a fourth fuel filter with a fourth filter element;
• 8th a longitudinal section through a fifth filter element;
• 9 a top view of the fifth filter element 8th ; and
• 10 a sectional partial view of the area X of the fifth filter element 8th .

Embodiments of the invention

1 shows a first fuel filter 10 with a first filter element 12th for multi-stage cleaning of a fuel. The first filter element 12th is in a filter housing 14th of the first fuel filter 10 arranged. The filter housing 14th has a filter bowl or filter housing body 16 on. One lid 18th of the filter housing 14th is on the filter housing body 16 unscrewed.

The first filter element 12th has a ventilation pipe 20th on. Via the ventilation pipe 20th can air out of the first fuel filter 10 via a return 22nd be fed back into a tank (not shown). On the return line 22nd opposite end 24 of the ventilation pipe 20th is a check valve 26th arranged. The check valve 26th opens at an overpressure of more than approx. 0.4 bar in the direction of the return 22nd or an arrow 28 . The check valve 26th can therefore be easily opened to allow the air to be quickly removed from the first fuel filter 10 to enable. The air is drained in the direction of the arrow 28 . The check valve 26th is in the lid 18th of the filter housing 14th easy to assemble thanks to a snap connection 30th attached. The check valve 26th prevents fuel from draining out of the first fuel filter 10 at rest one with the first fuel filter 10 fluidically connected internal combustion engine (not shown). This enables the internal combustion engine to be started quickly.

2 shows the first filter element 12th . From a comparison of the 1 and 2 it can be seen that the first filter element 12th one end via a check valve seal 32 (please refer 1 ) of the check valve 26th and at the other end via a double seal 34 (please refer 2 ) to the filter housing 14th (please refer 1 ) is sealed. The double seal 32 includes a first seal 36 and a second seal 38 , both of which are designed in the form of O-rings. It is still off 2 it can be seen that the first filter element 12th axially symmetrical to its filter element longitudinal axis 40 is trained.

3 shows a second filter element 42 a second fuel filter (not shown). Out 3 it can be seen that the second filter element 42 Bayonet protrusions 44 , 46 , 48 having. The bayonet protrusions 44 , 46 , 48 each have a stop 50 , 52 , 54 on. The attacks 50 , 52 , 54 are designed such that a locking of bayonet receptacles (not shown), which are arranged or formed in a cover of a filter housing, with the bayonet projections 44 , 46 , 48 occurs when the cover is unscrewed. The second filter element 42 can then be removed together with the lid. This is referred to in the description of 6th received again. The bayonet protrusions 44 , 46 , 48 are in one piece with a first end plate 56 of the second filter element 42 educated.

4th shows the second filter element 42 in a sectional view. Out 4th it becomes clear that the filter elements according to the invention, here the second filter element 42 , are designed for multi-stage cleaning of a fuel.

The second filter element is used for multi-stage cleaning 42 a particulate filter media 58 on that between the first end disk 56 and a second end plate 60 is arranged. The particulate filter medium 58 is for the fluid-tight separation of a raw side 62 from a clean side 64 with the end plates 56 , 60 welded.

The second filter element 42 includes a coalescing medium for multi-stage water separation 66 , a sedimentation gap 68 and a final separator screen 70 . The particulate filter medium 58 supports itself together with the coalescing medium 66 on a support body 72 of the second filter element 42 from the pressure exerted by the fuel against the second filter element 42 to withstand.

A ventilation pipe runs centrally in the longitudinal direction of the filter element 74 . The ventilation pipe 74 is designed in the form of a support tube that extends over the first end plate 56 protrudes so that it can easily be contacted fluidically on the top.

5 shows a further sectional view of the second filter element 42 . Out 5 it can be seen that the second filter element 42 a double seal on the underside 76 with a first seal 78 and a second seal 80 having. The first seal 78 seals the second filter element 42 radial to the longitudinal axis of the filter element 82 outwards while the second seal 80 the second filter element 42 radially inwards to the longitudinal axis of the filter element 82 seals out. The one when inserting the second filter element 42 resulting normal forces on the first seal 78 and the second seal 80 are thus opposite, namely to the longitudinal axis of the filter element 82 down (in the case of the first seal 78 ) and from the longitudinal axis of the filter element 82 away (in the case of the second seal 80 ). The opposing normal forces cause a partial force compensation and thus a lower mechanical load on the second filter element 42 .

6th shows a third fuel filter 84 with a third filter element 86 . The third filter element 86 is in a filter housing 88 arranged. The filter housing 88 has a return 90 for air return into a tank (not shown). A fuel discharge 92 of the filter housing 88 serves to divert purified fuel to an internal combustion engine (not shown). The fuel discharge 92 is essentially ring-shaped to a longitudinal axis of the filter element 94 educated. The fuel discharge 92 is of a ring-shaped drainage 96 surrounded, in which a sedimentation gap 98 of the third filter element 86 opens or fluidically with the sedimentation gap 98 connected is. The drainage 96 opens into a water collection space 100 or is fluidic with the water collection space 100 connected.

The filter housing 88 furthermore has a drainage channel 102 on. The gutter 102 is used to return fuel from a raw side 104 of the third fuel filter 84 to the tank (not shown) when changing the third filter element 86 .

To change the third filter element 86 becomes a lid 106 of the filter housing 88 that has a threaded connection 108 , here a right-hand thread connection, with a filter housing body 110 of the filter housing 88 is connected, from the filter case body 110 unscrewed. When unscrewing the lid 106 , ie when the lid is rotated 106 counterclockwise (in plan view), bayonet projections of the third filter element engage behind 86 respective bayonet mounts of the lid 106 . In 6th is a first bayonet projection 112 visible, the first bayonet mount 114 engages behind. The lid 106 is turned up to the stop (see stops 50 , 52 , 54 in 3 ). By further turning or unscrewing the cover 106 becomes the third filter element 86 rotated and can be used together with the lid 106 from the filter housing body 110 can be removed. The lid 106 thus serves as a handle for the third filter element 86 .

When removing the third filter element 86 first opens a first seal 116 of the third filter element 86 the fluidic connection between the raw side 104 and drainage channel 102 so that fuel from the raw side 104 over the drainage channel 102 can expire. Only then, i.e. after further movement of the third filter element 86 upwards, a second seal opens 118 the connection between the clean side 120 and the gutter 102 so that contamination of the clean side 120 is avoided by unfiltered fuel from the raw side. The seals 116 , 118 thus represent a double seal, which the drainage channel 102 when removing the third filter element 86 opens sequentially.

7th shows a fourth fuel filter 122 . The fourth fuel filter 122 comprises a fourth filter element 124 . The fourth fuel filter 122 has a check valve 126 on that via a snap connection 128 on a lid 130 the fourth fuel filter 122 is attached. The check valve 126 is in a fastener 132 arranged. The fastener 132 has a cone at one end 134 for easy adjustment of the fastening element 132 - and thereby the lid 130 - on the fourth filter element 124 on: When assembling the cover 130 can the cone 134 easily into a ventilation tube 136 of the fourth filter element 124 to be introduced. The assembly of the fourth fuel filter 122 this makes it particularly user-friendly.

8th shows a fifth filter element 138 . The fifth filter element 138 has a first end plate 140 on that a check valve 142 includes. 8th FIG. 13 is a plan view of a longitudinal section along the plane XIII-XIII according to FIG 9 .

9 shows a top view of the fifth filter element 138 . Out 9 it can be seen that on the first end plate 140 Bayonet protrusions 144 , 146 , 148 are formed, which engage in the bayonet mounts (not shown) when a cover is opened (not shown), so that the fifth filter element 138 together with the cover can be removed from a filter housing body (not shown).

10 FIG. 13 shows an enlarged view of the area X in FIG 8th . Out 10 it can be seen that the check valve 142 in a press fit in a recess 150 the first end disk 140 is arranged. This enables a particularly cost-effective production of the fifth filter element 138 (see 8th ).

In summary, the invention relates to a multi-stage cleaning filter element and a fuel filter with such a filter element. The filter element has a particle filter medium, a coalescing medium, a sedimentation gap and a final separator screen. The filter element is arranged in a filter housing of the fuel filter which comprises a filter housing body and a cover screwed onto the filter housing body. For convenient replacement of the filter element, the fuel filter is designed in such a way that at least one bayonet projection of the filter element engages behind a corresponding bayonet receptacle when the cover is unscrewed from the filter housing body, so that the cover - together with the filter element arranged on it via the bayonet connection - can be removed. The filter element is preferably a filter element with a ventilation pipe for ventilating the fuel filter.

Claims (9)

Filter element (12, 42, 86, 124, 138) for a fuel filter (10, 84, 122) of a motor vehicle, the filter element (12, 42, 86, 124, 138) in a filter housing (14, 88) of the fuel filter ( 10, 84, 122) can be used and the filter element (12, 42, 86, 124, 138) for the multi-stage cleaning of a fuel has a particle filter medium (58), a coalescing medium (66), a sedimentation gap (64, 98) and a final separator sieve ( 70), wherein the filter element (12, 42, 86, 124, 138) furthermore has a bayonet projection (44, 46, 48, 112, 144, 146, 148) which is used for engaging behind a bayonet receptacle (114) in a cover ( 18, 106, 130) of the filter housing (14, 88), in which the filter element (12, 42, 86, 124, 138) has a double seal (34, 76) towards the filter housing (14, 88), which in particular is arranged on an end plate (60) of the filter element (12, 42, 86, 124, 138), which preferably in the installed position of the filter element (12, 42, 86, 124, 138) below a is arranged. Filter element after Claim 1 wherein the particle filter medium (58) is arranged between a first end plate (56, 140) and a second end plate (60) of the filter element (12, 42, 86, 124, 138). Filter element after Claim 1 or 2 , in which the filter element (12, 42, 86, 124, 138) has a ventilation tube (20, 74, 136) running along the filter element longitudinal axis (40, 82, 94). Fuel filter (10, 84, 122) with a filter housing (14, 88) and a filter element (12, 42, 86, 124, 138) according to one of the preceding claims, wherein the filter housing (14, 88) has a cover (18, 106 , 130) which can be screwed onto a filter housing body (16, 110) and the cover (18, 106, 130) has a bayonet receptacle (114) on the inside which is designed such that the bayonet projection (44, 46, 48, 112 , 144, 146, 148) engages in the bayonet receptacle (114) when the cover (18, 106, 130) is unscrewed from the filter housing body (16, 110). Fuel filter Claim 4 in connection with a filter element Claim 3 , in which the fuel filter (10, 84, 122) at one end of the ventilation pipe (20, 74, 136) has a check valve (26, 126, 142) which is designed such that it blocks in the event of a flow interruption. Fuel filter Claim 5 , in which the check valve (26, 126, 142) is fastened in the fuel filter (10, 84, 122) with a snap connection (30, 128), in particular in a fluid-tight manner. Fuel filter Claim 5 or 6th , in which the check valve (26, 126) in the cover (18, 106, 130) of the filter housing (14, 88) is attached. Fuel filter according to one of the Claims 4 to 7th , in which the filter housing (14, 88) has a drainage channel (102) for draining fuel when the filter element (12, 42, 86, 124, 138) is removed from the filter housing (14, 88). Fuel filter Claim 8 in connection with a filter element Claim 4 , in which the drainage channel (102) is arranged or designed in such a way that when the filter element (12, 42, 86, 124, 138) is removed from the filter housing (14, 88) a first seal (36, 78) of the double seal ( 34, 76) seals the connection to a clean side (64, 120) of the fuel filter (10, 84, 122) longer than a second seal (38, 80) of the double seal (34, 76) seals the connection to a raw side (62, 104) of the fuel filter (10, 84, 122).

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