DE102012216355A1 - Fuel filter with a water collection room - Google Patents

Abstract

The invention relates to a fuel filter (1), in particular an internal combustion engine, with a housing (2), with a filter element (4) arranged in it and through which fuel to be filtered can flow, and with a collecting space (30) located below during operation for receiving water separated from the fuel, the collecting space (30) being formed by a transparent pot (3) which is tightly connected to the rest of the housing (2). The fuel filter (1) according to the invention is characterized in that the housing (2) encloses the outside of the pot (3) in a form-fitting manner and that the housing (2) has at least one viewing opening (24) in its area (23) surrounding the pot.

Description

The present invention relates to a fuel filter, in particular an internal combustion engine, having a housing, arranged therein, to be filtered by a fuel filter element and with a lower lying in operation plenum for receiving separated from the fuel water, the plenum by a with the remaining housing is tightly connected, transparent pot is formed.

A fuel filter of the type mentioned is out DE 299 15 146 U1 known. The pot forming the plenum is a downwardly extending extension of the housing made of sheet metal and is fixed by its upper edge in the housing by an adhesive bond. In addition, the pot can be held in the housing by a positive connection. The pot is made of a transparent plastic, to see the level of water accumulated in the pot from the outside. In addition, the pot can be formed on the outside with integral reinforcing ribs.

Another relevant fuel filter is off DE 199 43 240 A1 known in which the collecting space forming pot is screwed from below with the interposition of a sealing ring in the housing. The pot also consists of a transparent plastic.

A disadvantage is considered in these known fuel filters that the pot is not sure able to withstand the occurring in practice fuel pressures permanently harmless. The reason for this is that a sufficient, defined pressure resistance of the pot with a transparent plastic is not achievable, since this can not be reinforced with fibers, such as glass or carbon fibers, which would prevent the desired transparency.

Another fuel filter is off DE 10 2009 005 851 A1 known. The fuel filter has a housing and a filter element disposed within the housing. The housing has an open top end and a substantially closed bottom end. The housing is made of an opaque plastic, except for a window in the housing, which consists of a substantially transparent plastic. The essentially transparent plastic of the window is insert-molded with the opaque plastic. The filter element is disposed in the housing for filtering fuel. The housing defines a water collection space below the filter element, the window of the housing being positioned to overlap at least a portion of the water collection space to permit water level monitoring.

In this fuel filter is considered disadvantageous that on the one hand the production of the housing because of the complicated casting process ("insert mold") is relatively expensive and that on the other hand can not be guaranteed that the housing in the region of its window or its windows sufficient and has durable pressure resistance and tightness.

For the present invention, therefore, the object is to provide a fuel filter of the type mentioned above, which avoids the disadvantages mentioned above and in which in particular a permanent compressive strength and tightness of the collecting space for separated water forming pot is ensured, at the same time the water level in Collection space from the outside should remain visually well recognizable.

The object is achieved according to the invention with a fuel filter of the type mentioned, which is characterized in that the housing surrounds the outside of the pot form fit and that the housing has at least one show opening in its area surrounding the pot.

With the invention, it is advantageously achieved that the area of the housing enclosing the exterior of the pot absorbs the pressure forces which act on the inside of the pot and which causes the pressurized fuel in the interior of the fuel filter, and thus largely relieves and relieves the pot from the pressure forces Protects damage. Since the housing, including its pot enclosing area, does not have to be transparent, it can easily be made from a suitably stable material. Advantageously, the pot has to absorb only lower forces, which makes it possible to use a less stable, transparent material without disadvantageous consequences and without risks. Furthermore, it is advantageous that the housing on the one hand and the pot on the other hand can be initially produced as separate parts, which keeps the production simple. The show opening is appropriately designed in shape and size, on the one hand ensures good visibility of the water level in the pot and on the other hand does not affect a sufficient support of the pot against the pressure forces occurring.

Preferably, the housing has in its area surrounding the pot a plurality of display openings distributed in the circumferential direction. This ensures that the level of water in the pot is visible from different directions is, so it does not matter in which rotational position, the housing is arranged relative to the viewing direction of the fuel filter waiting operators.

In order to ensure a sufficiently high field of view and at the same time a good support of the pot, the / each display opening preferably has a round or an oblong-oval or elliptical, running in the longitudinal direction of the housing outline shape. Such a shape of the inspection opening (s) prevents tearing of the pot in the area of mechanical stress peaks that would occur at sharp corners and angles. Even angular outline of the show opening (s) with sufficient for avoiding voltage spikes rounded corners are conceivable and suitable.

For cost-effective manufacturability as a mass part and a low weight, the housing is preferably made of a fiber-reinforced opaque plastic and the pot preferably made of an unreinforced transparent plastic. With these materials, a cost-effective mass production, especially as injection molded parts, possible, wherein the material of the housing absorbs the forces caused by the pressure of the fuel and the material of the pot ensures the visibility of the water level in the water collecting space.

Modern fuel filters use an interchangeable filter element which requires that the fuel filter be opened for the purpose of replacing the filter element. In order to make this possible as simple as possible, the invention proposes that the housing is designed as a cup-shaped lid which can be attached to a filter head with a fuel inlet connection and a fuel outlet connection, preferably a screw cap. The filter head is firmly mounted, for example, on an internal combustion engine or in an engine compartment of a motor vehicle and connected to the necessary lines. For the maintenance of the fuel filter then only the housing must be unscrewed from the filter head and screwed after changing the filter element again.

In order to ensure that no fuel can get into the area between housing and pot and can escape through the show opening or show openings, the pot is expediently sealingly inserted into the housing with the interposition of a seal arranged in the region of the upper, open end of the pot.

Alternatively, the pot can be inserted into the housing and adhesively bonded or welded at its upper, open end to the housing. The welding may for example be a Reibverschweißung, since expedient the housing and the pot in the region of their junction are circular.

According to a specific embodiment, it is preferably provided that the pot has at its open end a radially outwardly projecting collar and that the housing has on its inner periphery a step which in the assembled state of the pot and housing with the collar by means of the seal or an adhesive layer or a weld seam sealingly cooperates. With this embodiment, a tight connection between the housing and pot is simplified, thereby achieving a higher level of safety for a lasting over the life of the fuel filter remaining tightness.

To be able to remove in the pot accumulated, separated from the fuel water without disassembly of the fuel filter, expediently the pot, starting from its lowest in operation, a leading out through the housing water drainage channel with a drain valve.

In this case, the drain valve is preferably designed as a screw valve with a hose connection for a water discharge hose. By means of a filter drainage system, the water collected in the pot can be deliberately and safely discharged into a collecting tank via the water discharge hose connected to the hose connection without the risk of contamination of the environment.

Finally, the invention still provides that the filter element has on its side facing the pot feet, which are supported in the installed state on a filter element facing the edge of the pot. In this way, the pot is used for an exact axial positioning of the filter element in the housing, so that separate positioning means can be omitted for this purpose. At the same time, the gap space remaining between the feet allows a passage of water separated from the fuel at the filter element into the collecting space within the pot.

In the following an embodiment of the invention will be explained with reference to a drawing. The figures of the drawing show:

1 a fuel filter in side view,

2 the fuel filter off 1 in a longitudinal section,

3 the housing of the fuel filter in an exploded view of its individual parts, in longitudinal section, and

4 the housing off 3 in assembled condition, again in longitudinal section.

1 The drawing shows a fuel filter 1 in a side view. The upper part of the fuel filter 1 forms a filter head 10 that with a fuel inlet connection 11 and a fuel drain port 12 is designed to connect corresponding fuel lines. Furthermore, the filter head 10 not shown here elements for mounting on, for example, the engine block of an associated internal combustion engine. In the upper part of the filter head 10 is in a conventional manner a fuel hand pump 13 arranged, which is used when an associated fuel system must be filled with fuel, for example after a fueling of the tank of an associated motor vehicle.

From below is with the filter head 10 a housing 2 connected, bolted here. The housing 2 is cup-shaped in its basic form and at its upper, with the filter head 10 connected end open. In its lower area 23 encloses the housing 2 positive fit one in the interior of the area 23 arranged pot 3 , The pot 3 forms in its interior a collecting space for water, which from the the fuel filter 1 flowing fuel, in particular diesel fuel, is deposited. The pot 3 consists of a transparent material, in particular transparent plastic. The housing 2 including his area 23 It also expediently consists of a plastic which is fiber-reinforced for strength reasons, for example with glass or carbon fibers, and is therefore not transparent, but has a much higher mechanical strength and thus compressive strength than the pot 3 ,

In his area 23 owns the housing 2 several, here four evenly distributed over the circumference openings 24 , through the outside of the pot 3 is visible from the transparent material. In this way, a water level in the pot 3 be visually perceived by an operator from any circumferential direction.

Due to the two-shell construction in the lower area 23 of the housing 2 with the inner, transparent pot 3 and the outside, the pot 3 enclosing area 23 of the housing 2 is also in the range of the pot 3 a defined, high pressure resistance of the housing 2 in general and especially the pot 3 guaranteed, as this outside of the area 23 of the housing 2 is enclosed positively. The inside from the pressure of the fuel in the housing 2 exerted forces are from the pot 3 outwards to the area surrounding it 23 derived from the housing. Thus, also in the area of the transparent pot 3 a high pressure resistance and thus permanent security against leaks or even bursting ensured without the visibility of the water level in the pot 3 is impaired.

At the bottom of the case 2 is a drain valve 34 arranged, which is designed here as a screw valve and in its interior a water drainage channel 33 contains. This is at the bottom, outer end as a hose connection 35 formed on which a water discharge hose when needed, that is, when draining water from the pot 3 , is attachable.

The 2 The drawing shows the fuel filter 1 out 1 in a longitudinal section. Top in 2 is again the filter head 10 with the fuel hand pump 13 visible, noticeable. Next is now a standard check valve 14 inside the filter head 10 visible, noticeable. On its underside has the filter head 10 an internal thread 15 with which the housing 2 by means of an outer thread formed on its upper end 25 with the interposition of a sealing ring 26 sealing, but detachable, is screwed on.

Internally 20 of the upper part of the housing 2 is a filter element 4 arranged, consisting of a hollow cylindrical filter material body 40 that consists of an upper end disc 41 and a lower end disc 42 edged on the front side. Inside the filter cloth body 40 is a grid-shaped support body 44 arranged, the filter cloth body 40 is supported at its flow radially from outside to inside against the forces occurring. By means of a in his upper end disc 41 provided central aperture is the filter element 4 to the filter head 10 easily detachable infected. During maintenance of the fuel filter 1 can after unscrewing the case 2 a spent filter element 4 withdrawn and through a fresh filter element 4 be replaced. After screwing back the housing 2 to the filter head 10 is the fuel filter 1 ready for use again.

In the area below 23 of the housing 2 is the transparent pot 3 arranged, where it is clearly visible that the area 23 of the housing 2 the pot 3 on the outside, with the exception of the display openings 24 , encloses a form-fitting manner. On the pot 3 pressure forces exerted from the inside are thus applied to the area 23 of the housing 2 immediately forwarded. Through the transparent pot 3 through are two of the show openings shown here in dashed lines in the background 24 in the area 23 of the housing 2 recognizable.

At its upper edge has the pot 3 a radially outwardly projecting collar 31 , Immediately below the collar 31 is on the inner circumference of the housing 2 a step 21 trained on the collar 31 sealingly rests. The seal is here for example by means of a weld 32 causes, which is preferably produced by friction welding. Alternatively, instead of the weld 32 also an adhesive seam or a separate sealing ring may be provided.

At the bottom of the lower end disc 42 of the filter element 4 are distributed over the circumference radially outside several, here four feet 43 molded, located on the top of the pot 3 support. Due to the sectional view are of the four feet 43 in 2 only two visible. Between the feet 43 are gap areas formed by which on the outer circumference of the filter element 4 separated water from the fuel into the plenum 30 inside the pot 3 can flow.

To drain in the collection room 30 of the pot 3 accumulated water serves the drain valve 34 , By loosening the trained as a screw valve drain valve 24 by means of a suitable screwing tool is the through the drain valve 34 running water drainage channel 33 open. On the hose connection 35 a water discharge hose, not shown here, can be attached to the drained water targeted and without risk of pollution z. B. to derive an external disposal container.

In 3 is the case 2 represented with its individual parts in an exploded view in longitudinal section. In the center of 3 is the case 2 visible, which is open at the top and on its outer circumference the external thread 25 having. Above is the sealing ring 26 Visible to the sealing of the housing 2 against the in 3 not shown filter head 10 serves. In the area below 23 of the housing 2 are two of the four show openings 24 visible, noticeable. At the bottom is the case 2 with a central opening for the drain valve 34 educated.

Top in 3 is the pot 3 from the transparent material with its molded-on collar at the top 31 shown. In its central lower area has the pot 3 also an opening for receiving the drain valve 34 ,

At the bottom of 3 is the drain valve 34 shown, which with the interposition of a sealing ring 36 in the pot 3 can be screwed.

In the manufacture of the fuel filter 1 be the case 2 and the pot 3 as well as the others in 3 shown items initially separately manufactured, the housing 2 expedient of a fiber-reinforced, opaque plastic and the pot 3 is injected from an unreinforced, transparent plastic. The pot 3 is then from above into the housing 2 introduced until the pot 3 in the lower area 23 of the housing 2 lies to rest and is enclosed by this form-fitting. In the area of the stage 21 and the collar 31 be the case 2 and the pot 3 sealed together, as welded or alternatively glued or sealed by means of a separate sealing ring.

It is also conceivable the housing area 23 and the pot 3 at their common contact surfaces over the entire surface or at least in the edge region of the display openings 24 to connect with each other, so that even when loaded from the outside of the pot 3 through the area 23 of the housing 2 is supported. The connection can be made here for example by welding or gluing.

From below, the drain valve designed as a screw valve is subsequently connected 34 in the pot 3 with interposition of the sealing ring 36 screwed in, then the housing 2 with the exception of its open upper side is sealed liquid-tight.

The assembled state of in 3 shown items is in 4 shown, also here in longitudinal section. The sealing ring 26 is now in the area of the external thread 25 on the outer circumference of the housing 2 placed. The pot 3 is located in the lower area surrounding it 23 of the housing 2 and is in the range of level 21 and the collar 31 by means of the weld 32 sealed. The drain valve 34 is in the pot 3 with interposition of the sealing ring 36 screwed. Through the transparent pot 3 through are in the background two of the dashed lines again shown here 24 recognizable.

To drain water from the plenum 30 inside the pot 3 becomes the drain valve 34 in the pot 3 unscrewed so far that the sealing ring 36 out of contact with the pot 3 arrives. In this way, the water drainage channel 33 opened and that in the collection room 30 located water can drain. In this case, an operator through the show openings 24 observe the level of the water and the drain valve 34 Close by tightening once the water is completely out of the plenum 30 has drained off and in the collection room 30 only fuel is left.

LIST OF REFERENCE NUMBERS

1

 Fuel filter

10

 filter head

11

 Fuel inlet port

12

 Fuel outlet port

13

 Fuel hand pump

14

 check valve

15

 inner thread

2

 casing

20

 housing interior

21

 step

23

 enclosing area

24

 Look openings

25

 external thread

26

 seal

3

 pot

30

 plenum

31

 collar

32

 Weld

33

 Water discharge channel

34

 drain valve

35

 hose connection

36

 seal

4

 filter element

40

 Filter cloth body

41

 upper end disc

42

 lower end disc

43

 feet

44

 support body

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

• DE 29915146 U1 [0002]
• DE 19943240 A1 [0003]
• DE 102009005851 A1 [0005]

Claims (11)

Fuel filter ( 1 ), in particular an internal combustion engine, with a housing ( 2 ), with a arranged in this, to be filtered by fuel filter element ( 4 ) and with a downstairs collecting space ( 30 ) for receiving separated from the fuel water, wherein the collecting space ( 30 ) by one with the rest of the housing ( 2 ) tightly connected, transparent pot ( 3 ), characterized in that the housing ( 2 ) the exterior of the pot ( 3 ) encloses form-fitting and that the housing ( 2 ) in its area enclosing the pot ( 23 ) at least one show opening ( 24 ) having. Fuel filter according to claim 1, characterized in that the housing ( 2 ) in his the pot ( 3 ) enclosing area ( 23 ) several distributed in the circumferential direction show openings ( 24 ) having. Fuel filter according to claim 1 or 2, characterized in that the / each show opening ( 24 ) has a round or an oblong-oval or elliptical, running in the longitudinal direction of the housing, outline shape. Fuel filter according to one of claims 1 to 3, characterized in that the housing ( 2 ) made of a fiber-reinforced opaque plastic and the pot ( 3 ) consists of an unreinforced transparent plastic. Fuel filter according to one of claims 1 to 4, characterized in that the housing ( 2 ) as a cup-shaped, to a filter head ( 10 ) with fuel feed connection ( 11 ) and fuel drain connection ( 12 ) hanging attachable lid, preferably screw cap is executed. Fuel filter according to one of claims 1 to 5, characterized in that the pot ( 3 ) with an interposition in the region of the upper, open end of the pot ( 3 ) arranged sealing in the housing ( 2 ) is used. Fuel filter according to one of claims 1 to 5, characterized in that the pot ( 3 ) in the housing ( 2 ) and sealed at its upper, open end with the housing ( 2 ) is glued or welded. Fuel filter according to claim 6 or 7, characterized in that the pot ( 3 ) at its open end a radially outwardly projecting collar ( 31 ) and that the housing ( 2 ) on its inner circumference a step ( 21 ), which in the assembled state of Topf ( 3 ) and housing ( 2 ) with the collar ( 31 ) by means of the seal or an adhesive layer or a weld ( 32 ) cooperates sealingly. Fuel filter according to one of claims 1 to 8, characterized in that the pot ( 3 ), starting from its lowest point in operation, one through the housing ( 2 ) leading to the outside water drainage channel ( 33 ) with a drain valve ( 34 ) having. Fuel filter according to claim 9, characterized in that the drain valve ( 34 ) as screw plug with a hose connection ( 35 ) is designed for a water discharge hose. Fuel filter according to one of claims 1 to 10, characterized in that the filter element ( 4 ) at his the pot ( 3 ) facing side feet ( 43 ), which in the installed state on a the filter element ( 4 ) facing edge of the pot ( 3 ).

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