FILTER DEVICE

Description

[0001] The invention relates to a filter element.

[0002] A filter device is known from the subsequently published DE 10 2020 004 489. The filter device comprises a filter housing having a connection point for the supply of an unfiltered stream and another connection point for the discharge of a filtrate stream. A hollow cylindrical filter element with a filter material is arranged in the filter device to filter unfiltered stream. Furthermore, a separating device is provided to separate the connection points from one another. This separating device is arranged in the filter housing in the form of an inclined partition wall and is rotatable to block the supply and discharge. Such a filter device offers many advantages when changing the filter element, particularly when the hydraulic lines connected to the connection points are depressurized.This is because the filter element can then be removed from the filter device after unscrewing a cover, with relatively little fluid flowing from the hydraulic lines into the filter housing.

[0003] DE 10 2008 036 055 A1 describes a filter element for a filter device with the features in the preamble of claim 1, having a filter housing which has at least two connection points, such as an inlet for unfiltered material and an outlet for filtrate, and accommodates a replaceable filter element, wherein at least one valve device is provided which, in an open position, enables a fluid flow between one of the connection points and the filter element and, in a closed position, prevents this fluid flow, wherein the valve device is movable between the open position and the closed position by means of a control device, wherein the filter element has a filter material which is arranged between the upper end cap and a lower end cap and is enclosed by the latter, and wherein a support tube with a perforation is provided on an inner side of the filter material.

[0004] Further filter elements can be found in DE 20 2019 102 432 U1, DE 10 2017 009 255 A1 and DE 20 2007 008 483 U1.

[0005] Based on this prior art, the invention is based on the object of providing a filter element that enables a service-friendly filter element change, in particular even when the hydraulic lines connected to the filter device are still under pressure.

[0006] A filter element having the features of patent claim 1 solves this problem.

[0007] According to the characterizing part of claim 1, it is provided that a slotted guide and at least one pin are provided on the upper end cap, and that the respective pin is arranged on an inner side of a threaded connector of the filter element.

[0008] Advantageous embodiments of the filter element emerge from the subclaims.

[0009] A valve device is provided which, in the open position, enables fluid flow between one of the connection points and the filter element and, in the closed position, prevents this fluid flow; and the valve device can be moved between the open position and the closed position by means of the control device. In this way, the flow of hydraulic fluid into the housing during a filter element change can be reliably prevented, even when the hydraulic lines are under pressure. This makes opening the filter housing and replacing the used filter element with a new one much easier. For example, no or fewer precautions need to be taken to prevent fluid from dripping from the filter housing. Furthermore, the arrangement of at least one valve in the valve housing limits or at least greatly reduces the amount of fluid in the filter housing that could escape when the filter housing is opened.

[0010] A particularly advantageous valve device is an inlet valve arranged in the fluid flow between the inlet and an outer side of the filter element. It has an inlet valve closing element that sealingly engages a valve seat on a housing bore of the inlet and is spring-loaded into the closed position. The inlet valve effectively blocks the fluid connection between the inlet and the filter element. The inlet valve closing element advantageously automatically moves into the blocking position when deactivated and when the fluid pressure in the supply decreases.

[0011] The inlet valve can be moved between the closed position and the open position by rotating the filter element; and a slotted guide can be provided on an adjacent end cap of the filter element, which moves the inlet valve closing member via a driver. In this way, the inlet valve can advantageously be opened and held open when the filter element is inserted into the filter housing.

[0012] When removing the filter element from the filter housing, the inlet valve is moved into the closed position, preferably before the filter housing is opened.

[0013] Advantageously, the driver is an integral part of the inlet valve closing element. This ensures that the driver is a captive part of the valve closing element, and direct actuation of the inlet valve closing element by the filter element's guide rail is ensured upon screwing in.

[0014] The guide can be a semicircular, annular axial projection on the adjacent end cap of the filter element, which has a greater radial distance from a longitudinal axis of the filter element at one end than at the other. Thus, upon the final 180° rotation of the filter element, the inlet valve is actuated and moved into its open position.

[0015] The axial projection of the guide can be larger at one end than at the other. This compensates for the filter element's approach to the inlet valve during screwing in of the filter element.

[0016] A sloped separating disc is conveniently mounted in the valve housing to separate the inlet from the outlet, and the inlet valve is mounted on the separating disc. This allows the inlet valve to be easily installed in the filter housing and replaced together with the separating disc. Another advantage is that the inlet valve and the separating disc can be prefabricated as an assembly.

[0017] A locking device can be provided on the separating disc, which securely holds the inlet valve closing element to the separating disc via at least one locking lug. A further advantage of this design is that the valve closing element can be easily slipped onto the locking device during assembly of the inlet valve.

[0018] The locking device can have three locking lugs, evenly spaced on a pitch circle, that guide the inlet valve closing element on the outside of the spring. This ensures easy attachment of the inlet valve closing element and its secure guidance. Furthermore, the spring is protected against kinking.

[0019] A particularly advantageous valve device is a drain valve that is arranged in the fluid flow between an inner side of the filter element and the drain. The valve has a drain valve closing element, preferably T-shaped in cross-section, that seals against a stop on a separating disc that separates the inflow and outflow, and is biased into the closed position by a spring. In this way, the drain valve can advantageously be opened and held open when the filter element is inserted into the filter housing. When the filter element is removed from the filter housing, the drain valve is moved into the closed position, preferably before the filter housing is opened.

[0020] The stop can be formed by an inserted ring, preferably L-shaped in cross-section. Such a ring can be arranged, for example, in a circumferential groove in a tubular nozzle. The ring can be flexible and preferably made of an elastomer.

[0021] The drain valve closing member is advantageously movable between the open position and the closed position by rotating the filter element; the filter element can be screwed into a connection piece on the separating disc via a threaded connector; and at least one axially projecting pin is provided on the threaded connector, which moves the drain valve closing member into the open position when the filter element is screwed into the separating disc. In this way, the drain valve can advantageously be opened and held open when the filter element is inserted into the filter housing. When removing the filter element from the filter housing, the drain valve is moved into the closed position, preferably before the filter housing is opened.

[0022] The pin can be located on the inside of the threaded connector. This arrangement allows the pin to be designed in the form of a straight rod that extends past the ring when the filter element is screwed in.

[0023] The threaded connector preferably has three or more pins arranged evenly offset along a pitch circle. This ensures that the drain valve closing element moves evenly axially when the filter element is screwed in, preventing it from jamming. A further advantage is that screwing in the filter element creates a flow opening of equal size all the way around. This can be enlarged by lifting the drain valve closing element off the pins if the fluid pressure on the element is sufficiently high.

[0024] The drain valve can be attached to a housing cover, preferably a removable one. The housing cover allows the separating disc to be mounted in the filter housing and the drain valve to be easily replaced or serviced.

[0025] The invention is explained in more detail below with reference to exemplary embodiments illustrated in the drawings, which are schematic and not to scale. They show: Fig. 1 a cross-section through a filter device; Fig. 2 a perspective view of the filter device of Fig. 1 ; Fig. 3 an exploded view of the filter device of Fig. 1 ; Fig. 4 a cross-sectional view of a cutting disc with an inlet valve and an outlet valve; Fig. 5 a view from below of the cutting disc of the Fig. 4 ; Fig. 6a perspective view of the cutting disc of Fig. 4; Figs. 7 and 8 show sectional views of a head part of the filter device; Figs. 9 to 11 show a sectional view, an external view, and a perspective view of a filter element; Figs. 12 to 14 show a sectional view, a top view, and a perspective view of an upper end cap of the filter element; Fig. 15 show a perspective view of a bypass valve; Figs. 16 to 19 show perspective views of a lower end cap of the filter element; Figs. 20 and 21 show a cross-sectional view and a perspective view of a housing main part; Figs. 22 and 23 show perspective views of a cover part; Fig. 24 show a sectional view of a housing lower part; Fig. 25 show a perspective view of a rotating part; Fig. 26 show an enlarged view of a holding device; Fig. 27 show a perspective view of the housing lower part of Fig. 24 ; and Figs. 28 to 30 are perspective views of a filter element inserted into the housing base.

[0026] Fig. 1 to 3show a filter device 10 with a filter housing 12, which has at least two connection points 14, 16, such as an inlet 14 for unfiltered material and an outlet 16 for filtrate, and accommodates a replaceable filter element 18. The filter housing 12 is designed in three parts and has a main housing part 20, a lower housing part 22 and a cover part 24. The main housing part 20 is essentially cylindrical, with circumferential ribs 26 projecting from the cylinder wall, which are hexagonal in shape on the circumference. In the area of ​​a housing head 28, the connection points for inlet 14 and outlet 16 are provided on opposite sides. These are also hexagonal on the outside. A housing bore 30 of the inlet 14 has a smaller diameter than a housing bore 32 of the outlet 16. The housing bores 30, 32 have an axial offset V from one another.The lower housing part 22 is screwed to the main housing part 20 from the underside via a thread 36 and sealed by a sealing ring (not shown in detail) in a circumferential groove. A cover part 24 is attached to the upper housing part 28 by means of four fastening screws 42.

[0027] At least one valve device 44 is provided, which in an open position OS enables a fluid flow between one of the connection points 14, 16 and the filter element 18 and prevents this fluid flow in a closed position SS. The valve device 44 is movable between the open position OS and the closed position SS by means of a control device 46, which comprises the lower housing part 22 and the filter element 18. For this purpose, an obliquely arranged separating disc 50 is inserted into the filter housing 12 from above through an opening 48 closed by the cover part 24, on which a valve device 44 in the form of an inflow valve 52 is provided. A ring 54 is provided on the separating disc 50 in a receiving socket 56, which cooperates with an outflow valve 58 provided on the cover part 24. The filter element 18 is screwed into the separating disc 50 with its threaded socket 60.

[0028] As the Fig. 4 to 8show in more detail, one valve device 44 is the inflow valve 52, which is arranged in the fluid flow between the inlet 14 and an outer side 61 of the filter element 18 and has an inflow valve closing member 62 which comes into sealing contact with a valve seat 64 on the housing bore 30 of the inlet 14 and is biased into the closed position SS by a spring 66. The inflow valve closing member 62 can be moved between the open position OS and the closed position SS by rotating the filter element 18. For this purpose, a slotted guide 70 is provided on an adjacent upper end cap 68 of the filter element 18, which moves the inflow valve closing member 62 via a driver 72. The driver 72 is fastened to a fastening part 74 of the inflow valve closing member 62. Three of these fastening parts 74 are provided, which are arranged evenly offset on a pitch circle.The driver 72 is thus an integral component of the inflow valve closing member 62.

[0029] As in the Fig. 9 to 14 As shown in more detail, the slotted guide 70 is a semicircular, partially annular axial projection 78 on the adjacent upper end cap 68 of the filter element 18, which has a greater radial distance A1 from a longitudinal axis LA of the filter element 18 at one end 82 than at another end 84. The axial projection 78 of the slotted guide 70 is also larger at one end 82 than at the other end 84, as can best be seen in Fig. 14 When viewed from the filter element 18, the height of the axial projection 78 increases in a counterclockwise direction.

[0030] The separating disc 50 is fixedly arranged in the filter housing 12 and rests on a shoulder 86 of the filter housing 12. On its outer circumference, the separating disc 50 is provided with a circumferential groove 88 in which a sealing ring 90 is arranged. Parallel to the longitudinal axis LA of the filter device 10, the separating disc 50 has the receiving socket 56. The aforementioned inflow valve 52 is arranged on this receiving socket 56. For this purpose, a locking device 92 is provided which projects laterally. The spring 66 is arranged in the locking device 92 and preloads the inflow valve closing member 62 into the closed position SS. The locking device 92 also has three locking lugs 94 which are hooked to the fastening parts 74 of the inflow valve closing member 62. Thus, a locking device 92 is provided on the cutting disc 50, which holds the inflow valve closing member 62 captively on the cutting disc 50 via at least one locking lug 94.The locking lugs 94 are arranged evenly offset on a pitch circle and guide the inflow valve closing member 62 on the outer side 96 of the spring 66.

[0031] As the Fig. 4 to 8further show that parallel to the longitudinal axis LA of the filter device 10, a valve device 44 in the form of the drain valve 58 is provided, which is arranged in the fluid flow between the inner side 98 of the filter element 18 and the outlet 16 and has a shut-off valve closing member 100 with a T-shaped cross section, which comes into sealing contact against a stop 102 on the separating disc 50, which separates the inlet 14 and the outlet 16, and is biased into the closed position SS by a spring 104. The stop 102 is formed by the ring 54, which has an L-shaped cross section and is inserted into a circumferential groove 106 in the receiving socket 56. The ring 54 is preferably made of an elastomer. The drain valve closing member 100 has a T-shaped cross section and is held in a base 108, which is arranged either on the cover part 24 of the filter housing 12 or in a cage 110.The base 108 has a sleeve 112 in which a rod 114 of the drain valve closing member 100 is slidably arranged. The rod 114 is surrounded on the outside by the spring 104.

[0032] On an inner side 116 of a threaded connector 60 of the filter element 18, a pin 118 is arranged, which is inserted into the Fig. 9 to 11 is visible. Preferably, three pins 118 are provided on the threaded connector 60, which are arranged evenly offset on a pitch circle. These pins 118 make it possible to lift the drain valve closing member 100 from the stop 102 when screwing the filter element 18 into the separating disc 50.

[0033] As the Figs. 22 and 23show in more detail, the cover part 24 essentially has the shape of a circular disk 120. On the outer circumference side, arc-shaped fastening arms 122 are provided on the circular disk 120, into which the fastening screws 42 can engage. Adjacent to the openings 124 of the fastening arms 122, indentations 128 are provided on the outer circumference 126 of the cover part 24 in order to be able to lift the cover part 24 from the main housing part 20 past the heads 130 of the fastening screws 42. This solution has the advantage that the cover part 24 can be detached and lifted off the main housing part 20 without having to unscrew the fastening screws 42 from the main housing part 20. On the underside 132, the cover part 24 has an axial extension 134 for centering and sealing against the main housing part 20.

[0034] The further construction of the filter device 10 below the upper end cap 68 of the filter element 18 is already known from the subsequently published DE 10 2020 004 489 and is therefore described below with reference to the Fig. 1 to 3 , 9 to 11 and 15 to 30 only described in overview.

[0035] The filter element 18 has a filter material 136 arranged between and enclosed by the upper end cap 68 and a lower end cap 138. A support tube 140 with a perforation 142 is provided on an inner side 98 of the filter material 136. The upper end cap 68 has four projections 144 arranged circumferentially and evenly offset on a pitch circle, which are intended to facilitate handling of the filter element 18 when removing it from the housing base 22.

[0036] The lower end cap 138 of the filter element 18 is constructed in several parts, with a surround ring 148 enclosing the filter material 136 and holding a bypass valve 150. The bypass valve 150 is replaceably inserted into the surround ring 148. This has a cage 152 with windows 154 in which a coarse-mesh filter fabric 156 is provided, as can be seen in the Fig. 15 can be seen. The bypass valve 150 has a bypass valve closing member 158, which is biased into the closed position SS by a spring 160. The bypass valve closing member 158 is T-shaped in cross-section and rests against a lower valve seat 162 on the rim ring 148.

[0037] A fastening ring 166 is connected to this edging ring 148 via four S-shaped spring bands 164. The fastening ring 166 has a larger diameter than the edging ring 148. The fastening ring 166 can be inserted into the lower housing part 92 and fastened in a locking manner. The fastening ring 166 has a flange 168 and a connecting piece 170 extending axially downward from the flange 168, which is provided on the outside with a locking collar 172, via which the filter element 18 can be releasably secured in the lower housing part 22 in a recess 174, which has an inwardly drawn-in detent 178 at an upper end 176.

[0038] On the flange 168, four drivers 180 are arranged - also evenly offset on a pitch circle - which have inclined surfaces 182 and vertically extending contact surfaces 184, which can engage with rotating parts 186 on the housing base 22. The rotating parts 186 are in the Figs. 24 and 25and also have a shape with an inclined surface 188 and a vertical surface 190, so that the drivers 180 and the rotating parts 186 can slide along one another in a clockwise direction of rotation of the lower housing part 22 when screwing it on and engage when rotating in the counterclockwise direction when unscrewing it.

[0039] The lower housing section 22 is secured to the main housing section 20 via a thread 192. The filter element 18 has a second thread 194 for fastening it to the separating disc 50. The thread pitches of these two threads 192, 194 differ to ensure that when the lower housing section 22 is unscrewed, the filter element 18 is first unscrewed from the separating disc 50 before being unscrewed together with the lower housing section 22 from the main housing section 20. The spring elements 138 between the lower end cap sections 148, 160 are provided to allow length compensation. When screwing in, the procedure is reversed. First, the filter element 18 is screwed into the separating disc 50 and then the lower housing section 22 is finally screwed onto the main housing section 20.

[0040] The functionality of the filter device is described below.

[0041] When the lower housing section 22 is unscrewed from the main housing section 20, the filter element 18 in the filter housing 12 rotates along with it. In a first phase, unscrewing the filter element 18 actuates the inlet valve 52 and the outlet valve 58, so that they move into the closed position SS due to the spring load. The spring elements 164 of the lower end cap 138 compress and thus enable compensation. In the second phase, when the filter element 18 is unscrewed from the recessed socket 56 of the separating disc 50, the filter element 18 rotates on the separating disc 50 while the lower housing section 22 is further unscrewed. In the third and final phase, the lower housing section 22 and the main housing section 20 are disengaged. However, the filter element 18 remains secured to the lower housing section 22 by a snap-in connection 172, 176 and is pulled out of the main housing section 20.Finally, the filter element 18 can be removed from the lower housing part 22 and replaced with a new filter element 18.

[0042] When installing the new filter element 18, it is placed on the lower housing section 22 and pushed into the main housing section 20. The lower housing section 22 is screwed onto the main housing section 20. The filter element 18 is rotated and screwed into the separating disc 50. By screwing in the filter element 18, the inlet valve 52 and the outlet valve 58 are also moved into the respective open positions OS. When the filter element 18 is fully screwed into the separating disc 50, the drivers 180 and rotating parts 186 on the lower end cap 138 and the lower housing section 22 can slide against each other via their respective inclined surfaces 182, 188, so that the lower housing section 22 can be fully screwed on without the filter element 18 rotating any further.

[0043] The filter device 10 demonstrates a solution for effectively separating an interior of a filter housing 12 from an inlet 14 and an outlet 16 by means of valve devices 44 when the filter housing 12 is unscrewed to replace the filter element 18. This has no equivalent in the prior art.

[0044] It is understood that terms such as "top" and "bottom" refer to the image plane of the respective drawing. In the actual installation situation, the filter device may be arranged at an angle to the vertical.

Claims

1. Filter element for a filter device with a filter housing (12) which has at least two connection points (14, 16), such as an inlet (14) for unfiltered medium and an outlet (16) for filtrate, and accommodates a replaceable filter element (18), wherein at least one valve device (44) is provided which, in an open position (OS), enables a fluid flow between one of the connection points (14, 16) and the filter element (18) and, in a closed position (SS), prevents this fluid flow, wherein the valve device (44) is movable between the open position (OS) and the closed position (SS) by means of an actuating device (46), wherein the filter element (18) comprises a filter material (136) which is arranged between the upper end cap (68) and a lower end cap (138) and is enclosed thereby, and whereby a supporting tube (140) with a perforation (142) is provided on an inner side (98) of the filter material (136), characterised in that a sliding guide (70) and at least one pin (118) is provided on the upper end cap (68), and in that the respective pin (118) is arranged on an inner side of a threaded socket (60) of the filter element (18).

2. Filter element according to claim 1, characterised in that the sliding guide (70) is an axial protrusion (78), which forms a semicircle and is annular in sections, on the upper end cap (68) of the filter element (18), which has a greater radial distance (A1) from a longitudinal axis (LA) of the filter element (18) at its one end (82) than at another end (84).

3. Filter element according to claim 2, characterised in that the axial protrusion (78) of the sliding guide (70) is larger at the one end (82) than at the other end (84) in such a manner that the height of the axial protrusion (78) increases in an anti-clockwise direction.

4. Filter element according to one of the preceding claims, characterised in that three or more pins (118), which are arranged evenly offset on a divided circle, are provided on the threaded socket (60).

5. Filter element according to one of the preceding claims, characterised in that the upper end cap (68) has four projections (144) on the circumference, arranged evenly offset on a divided circle.

6. Filter element according to one of the preceding claims, characterised in that the lower end cap (138) of the filter element (18) is made in multiple parts, in that an enclosing ring (148) encloses the filter material (136) and holds a bypass valve (150), and in that the bypass valve (150) is replaceably inserted into the enclosing ring (148).

7. Filter element according to claim 6, characterised in that the bypass valve (150) has a cage (152) with windows (154) in which a coarse-meshed filter fabric (156) is provided.

8. Filter element according to claim 6 or 7, characterised in that the bypass valve (150) has a bypass valve closing member (158), which is urged into the closed position (SS) by a spring (160), and in that the bypass valve closing member (158) is T-shaped in cross-section and comes into contact with a lower valve seat (162) on the enclosing ring (148).

9. Filter element according to one of claims 6 to 8, characterised in that a mounting ring (166), which has a larger diameter than the enclosing ring (148), is connected to the enclosing ring (148) via four S-shaped spring straps (164).

10. Filter element according to claim 9, characterised in that the mounting ring (166) has a flange (168) and a connection socket (170), extending axially downwards away from the flange (168), which socket is provided on the outside with a latching collar (172).

11. Filter element according to claim 10, characterised in that, arranged on the flange (168), evenly offset on a divided circle, are four drivers (180) which have inclined surfaces (182) and vertically extending contact surfaces (184).

12. Filter element according to one of the preceding claims, characterised in that it has second thread (194).