Filter element with multi-stage water-separating action and with bayonet connection, and fuel filter having a filter element of said type

Abstract

Disclosed is a filter element (86) with multi-stage cleaning, and a fuel filter (84) having such a filter element (86). The filter element (86) has a particle filter medium, a coalescer medium, a sediment gap (98) and a final separator screen. The filter housing has a filter housing body (110) and a cover (106) screwed onto the filter housing body (110). When the cover (106) is unscrewed from the filter housing body (110), at least one bayonet projection (112) of the filter element (86) engages behind a corresponding bayonet receptacle (114), such that the cover (106) can be removed together with the filter element (86) arranged thereon by way of the bayonet connection.

Claims

1. A filter element for a fuel filter of a motor vehicle, wherein the filter element is annular, and surrounds a longitudinal axis extending through a center of the filter element, the filter element configured and adapted to be inserted into a filter housing of the fuel filter; and the filter element for multi-stage cleaning of a fuel includes: a particle filter medium; a coalescer medium; a tubular support member on which the particle filter medium and the coalescer medium are supported' a sediment gap; a final separating element having a final separating screen; and a first end plate on a first axial end of the filter element, and a second end plate on an opposite second axial end of the filter element, wherein the particle filter medium and the coalescer medium are fixed onto the first end plate and onto the second end plate; wherein the final separating element extends from an interior of the filter element, and projects outwardly beyond the particle filter medium at the second axial end of the filter element; wherein the first end plate of the filter element has a plurality of bayonet projections configured to engage behind a bayonet receptacle in a cover of the filter housing; wherein the projections have a stop wall formed with the bayonet projections and extending radially outwardly to form a rotation stop, stopping rotation relative to the bayonet receptacle when engaged; wherein the filter element includes a ventilation pipe, the ventilation pipe is tubular having an outer tubular wall terminating at a first open end face and an opposite second open end face, the open end faces opening axially to an exterior of the ventilation pipe, wherein the ventilation pipe is arranged on and extending along the longitudinal axis in an interior of the filter element, the outer tubular wall of the ventilation pipe extending from the interior through the first end plate and projecting outwardly beyond the first end plate to terminate at the first open end face.

2. The filter element according to claim 1, wherein the particle filter medium is arranged between the first end plate and a second end plate of the filter element.

3. The filter element according to claim 2, wherein the filter element includes a double seal arranged on the second end plate, the double seal having: a first annular seal arranged at a radially outer side of the second end plate and configured to seal radially outwardly against an interior of the filter housing; a second annular seal arranged axially outwardly from the first annular seal and radially inwardly from the first annular seal, the second annular seal configured to seal radially inwardly wherein the double seal is arranged on the second end plate of the filter element which is arranged at the bottom in the installation position of the filter element.

4. A fuel filter, comprising: a filter housing; and a filter element, wherein the filter element is annular, and surrounds a longitudinal axis extending through a center of the filter element, the filter element configured and adapted to be inserted into the filter housing; and the filter element for multi-stage cleaning of a fuel includes: a particle filter medium; a coalescer medium; a sediment gap; and a final separating element having a final separating screen; a first end plate on a first axial end of the filter element, and a second end plate on an opposite second axial end of the filter element, wherein the particle filter medium and the coalescer medium are fixed onto the first end plate and onto the second end plate; wherein the final separating element extends from an interior of the filter element, and projects outwardly beyond the particle filter medium at the second axial end of the filter element; wherein the first end plate of the filter element has a plurality of bayonet projections configured to engage behind a bayonet receptacle in a cover of the filter housing; wherein the projections have a stop wall formed with the bayonet projections and extending radially outwardly to form a rotation stop, stopping rotation relative to the bayonet receptacle when engaged; wherein the filter element includes a ventilation pipe arranged on and extending along the longitudinal axis in an interior of the filter element, the ventilation pipe extending from the interior through the first end plate and projecting outwardly beyond the first end plate; wherein the cover can be screwed onto a filter housing; and the cover has on an inside the bayonet receptacle which configured such that the bayonet projections engage in the bayonet receptacle when the cover is unscrewed from the filter housing member; wherein the projections have a stop wall formed with the bayonet projections and extending radially outwardly to form a rotation stop, stopping rotation relative to the bayonet receptacle when engaged; wherein the filter element includes a ventilation pipe, the ventilation pipe is tubular having an outer tubular wall terminating at a first open end face and an opposite second open end face, the open end faces opening axially to an exterior of the ventilation pipe, wherein the ventilation pipe is arranged on and extending along the longitudinal axis in an interior of the filter element, the outer tubular wall of the ventilation pipe extending from the interior through the first end plate and projecting outwardly beyond the first end plate to terminate at the first open end face.

5. The fuel filter according to claim 4, wherein the fuel filter has at one end on the ventilation pipe a non-return valve which configured to shut off in the event of a flow being interrupted.

6. The fuel filter according to claim 5, wherein the non-return valve is fastened by a snap connection, in a fluid-tight manner, in the fuel filter.

7. The fuel filter according to claim 5, wherein the non-return valve is fastened directly to the cover of the filter housing, the non-return value inserted into an interior of the ventilation pipe through the first open end face.

8. The fuel filter according to claim 4, wherein the filter housing has a drainage channel for draining fuel during removal of the filter element from the filter housing.

9. The fuel filter according to claim 8, wherein the filter element includes a double seal arranged on a second end plate, the double seal having: a first annular seal arranged at a radially outer side of the second end plate and configured to seal radially outwardly against an interior of the filter housing; a second annular seal arranged axially outwardly from the first annular seal and radially inwardly from the first annular seal, the second annular seal configured to seal radially inwardly; wherein the double seal is arranged on the second end plate of the filter element which is arranged at the bottom in the installation position of the filter element; wherein the drainage channel is arranged or formed in such a way that when the filter element is removed from the filter housing the second annular seal of the double seal seals the connection to an output side of the fuel filter for longer than the first seal of the double seal seals the connection to an input side of the fuel filter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the invention are disclosed by the following detailed description of a plurality of exemplary embodiments of the invention, with reference to the figures of the drawings, which show details which are essential to the invention, and also from the claims.

(2) The features illustrated in the drawings are presented in such a way that the distinctive features according to the invention can be made clearly visible. The different features can each be implemented individually or in any combination in variants of the invention.

(3) In the drawings:

(4) FIG. 1 shows a longitudinal section through a first fuel filter having a first filter element;

(5) FIG. 2 shows a longitudinal section through the first filter element according to FIG. 1;

(6) FIG. 3 shows a perspective view of a second filter element for a second fuel filter (not shown);

(7) FIG. 4 shows a perspective representation of a longitudinal section of the second filter element according to FIG. 3;

(8) FIG. 5 shows a plan view of a further longitudinal section of the second filter element according to FIG. 3;

(9) FIG. 6 shows a longitudinal section through a third fuel filter having a third filter element;

(10) FIG. 7 shows a longitudinal section through a fourth fuel filter having a fourth filter element;

(11) FIG. 8 shows a longitudinal section through a fifth filter element;

(12) FIG. 9 shows a plan view of the fifth filter element according to FIG. 8;

(13) FIG. 10 shows a sectional detail view of the area X of the fifth filter element according to FIG. 8.

DETAILED DESCRIPTION

(14) FIG. 1 shows a first fuel filter 10 with a first filter element 12 for multi-stage cleaning of a fuel. The first filter element 12 is arranged in a filter housing 14 of the first fuel filter 10. The filter housing 14 has a filter container or filter housing 16. A cover 18 of the filter housing 14 is screwed onto the filter housing 16.

(15) The first filter element 12 has a ventilation pipe 20. By means of the ventilation pipe 20 air can be led out of the first fuel filter 10 via a return pipe 22 back into a tank (not shown). A non-return valve 26 is arranged at the end 24 of the ventilation pipe 20 opposite the return pipe 22. The non-return valve 26 opens with an overpressure of more than approximately 0.4 bar in the direction of the return pipe 22 or of an arrow 28. Thus the non-return valve 26 can be opened slightly in order to enable a fast discharge of the air from the first fuel filter 10. The outflow of the air takes place in the direction of the arrow 28. For ease of installation the non-return valve 26 is fastened in the cover 18 of the filter housing 14 by a snap connection 30. The non-return valve 26 prevents the fuel from running out of the first fuel filter 10 in the rest state of an internal combustion engine (not shown) fluidically connected to the first fuel filter 10. As a result the internal combustion engine can be started quickly.

(16) FIG. 2 shows the first filter element 12. From a comparison of FIGS. 1 and 2 it can be seen that the first filter element 12 is sealed, towards the filter housing 14 (see FIG. 1), at one end by means of a non-return valve seal 32 (see FIG. 1) of the non-return valve 26 and at the other end by means of a double seal 34 (see FIG. 2). The double seal 32 comprises a first seal 36 and a second seal 38 which are both designed in the form of O-rings. Furthermore, it can be seen from FIG. 2 that the first filter element 12 is formed axially symmetrically with respect to the longitudinal axis 40 of the filter element 40.

(17) FIG. 3 shows a second filter element 42 of a second fuel filter (not shown). It can be seen from FIG. 3 that the second filter element 42 has bayonet projections 44, 46, 48. The bayonet projections 44, 46, 48 in each case have a stop 50, 52, 54. The stops 50, 52, 54 are designed in such a way that bayonet receptacles (not shown), which are arranged or formed in a cover of a filter housing, are locked with the bayonet projections 44, 46, 48 when the cover is unscrewed. The second filter element can then be removed together with the cover. Reference is made to this again in the description of FIG. 6. The bayonet projections 44, 46, 48 are formed in one piece with a first end disc 56 of the second filter element 42.

(18) FIG. 4 shows the second filter element 42 in a sectional view. It is clear from FIG. 4 that the filter elements according to the invention, in this case the second filter element 42, are designed for multi-stage cleaning of a fuel.

(19) For multi-stage cleaning the second filter element 42 has a particle filter medium 58 which is arranged between the first end disc 56 and a second end disc 60. The particle filter medium 58 is welded to the end discs 56, 60 for fluid-tight separation of an input side 62 from a output side 64.

(20) For multi-stage water separation the second filter element 42 comprises a coalescer medium 66, a sediment gap 68 and a final separating screen 70. The particle filter medium 58 is supported, together with the coalescer medium 66, on a support member 72 of the second filter element 42, in order to withstand the pressure exerted by the fuel against the second filter element 42.

(21) A ventilation pipe 74 extends centrally in the longitudinal direction of the filter element. The ventilation pipe 74 is designed in the form of a support pipe which projects beyond the first end disc 56, so that it is easily fluidically contactable at the top.

(22) FIG. 5 shows a further sectional view of the second filter element 42. It can be seen from FIG. 5 that the second filter element 42 has at the underside a double seal 76 with a first seal 78 and a second seal 80. The first seal 78 seals the second filter element 42 radially with respect to the longitudinal axis of the filter element 82 towards the outside, whereas the second seal 80 seals the second filter element 42 radially inwards towards the longitudinal axis of the filter element 82. Thus the normal forces exerted on the first seal 78 and the second seal 80 during insertion of the second filter element 42 act in opposite directions, namely towards the longitudinal axis of the filter element 82 (in the case of the first seal 78) and away from the longitudinal axis of the filter element 82 (in the case of the second seal 80). The normal forces acting in opposite directions provide partial force compensation and as a result cause less mechanical loading of the second filter element 42.

(23) FIG. 6 shows a third fuel filter 84 with a third filter element 86. The third filter element 86 is arranged in a filter housing 88. The filter housing 88 has a return pipe 90 for returning air into a tank (not shown). A fuel outlet 92 of the filter housing 88 serves to discharge cleaned fuel to an internal combustion engine (not shown). The fuel outlet 92 is substantially annular with respect to a longitudinal axis of the filter element 94. The fuel outlet 92 is surrounded by an annular water outlet 96, into which a sediment gap 98 of the third filter element 86 opens or which is fluidically connected to the sediment gap 98. The water outlet 96 opens into a water collecting chamber 100 or is fluidically connected to the water collecting chamber 100.

(24) Furthermore, the filter housing 88 has a drainage channel 102. The drainage channel 102 serves for returning fuel from an input side 104 of the third fuel filter 84 to the tank (not shown) during changing of the third filter element 86.

(25) For changing of the third filter element 86, a cover 106 of the filter housing 88, which is connected via a threaded connection 108, in this case a right-handed threaded connection, to a filter housing member 110 of the filter housing 88, is unscrewed from the filter housing 110. During unscrewing of the cover 106, i.e. during rotation of the cover 106 anticlockwise (in plan view), bayonet projections of the third filter element 86 engage behind respective bayonet receptacles of the cover 106. In this connection FIG. 6 shows a first bayonet projection 112 which engages behind a first bayonet receptacle 114. The cover 106 is rotated until it reaches a stop (cf. stops 50, 52, 54 in FIG. 3). By further rotation or unscrewing of the cover 106 the third filter element 86 is also rotated and thus can be removed, together with the cover 106, from the filter housing member 110. Thus the cover 106 serves as a grip for the third filter element 86.

(26) During the removal of the third filter element 86, first of all a first seal 116 of the third filter element 86 opens the fluidic connection between the input side 104 and the drainage channel 102, so that fuel can drain from the input side 104 via the drainage channel 102. Only after this, that is to say after further movement of the third filter element 86 upwards, a second seal 118 opens the connection between the output side 120 and the drainage channel 102, so that a contamination of the output side 120 by unfiltered fuel from the input side is avoided. Thus the seals 116, 118 constitute a double seal which sequentially opens the drainage channel 102 during the removal of the third filter element 86.

(27) FIG. 7 shows a fourth fuel filter 122. The fourth fuel filter 122 comprises a fourth filter element 124. The fourth fuel filter 122 has a non-return valve 126, which is fastened by means of a snap connection 128 to a cover 130 of the fourth fuel filter 122. In this case the non-return valve 126 is arranged in a fastening element 132. The fastening element 132 has at one end a cone 134 for simple adjustment of the fastening element 132and as a result the cover 130to the fourth filter element 124. During the installation of the cover 130 the cone 134 can be easily introduced into a ventilation pipe 136 of the fourth filter element 124. As a result the installation of the fourth fuel filter 122 is particularly user-friendly.

(28) FIG. 8 shows a fifth filter element 138. The fifth filter element 138 has a first end disc 140 which comprises a non-return valve 142. FIG. 8 shows a plan view of a longitudinal section along the plane XIII-XIII according to FIG. 9.

(29) FIG. 9 shows a plan view of the fifth filter element 138. It can be seen from FIG. 9 that on the first end disc 140 bayonet projections 144, 146, 148 are formed which, during screwing on of a cover (not shown), engage in the bayonet receptacles (not shown) on the cover, so that the fifth filter element 138 together with the cover can be removed from a filter housing member (not shown).

(30) FIG. 10 shows an enlarged view of the area X according to FIG. 8. It can be seen from FIG. 10 that the non-return valve 142 is arranged with a press fit in a recess 150 in the first end disc 140. This enables a particularly cost-effective production of the fifth filter element 138 (see FIG. 8).

(31) To summarize, the invention relates to a multi-stage cleaning filter element as well as a fuel filter with such a filter element. The filter element has a particle filter medium, a coalescer medium, a sediment gap and a final separating screen. The filter element is arranged in a filter housing of the fuel filter which comprises a filter housing member and a cover screwed onto the filter housing member. For convenient changing of the filter element the fuel filter is formed in such a way that at least one bayonet projection of the filter element engages behind a corresponding bayonet receptacle during unscrewing of the cover from the filter housing member, so that the covertogether with the filter element arranged thereon by means of the bayonet connectioncan be removed. The filter element is preferably a filter element with a ventilation pipe for ventilation of the fuel filter.