FILTER DEVICE

Description

[0001] The invention relates to a filter device having the features in the preamble of claim 1.

[0002] Such 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 the 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 off the supply and discharge.Such a filter device offers many advantages when changing the filter element, especially when the hydraulic lines connected to the connection points are depressurized, because then the filter element can be removed from the filter device after unscrewing a cover, whereby relatively little fluid flows from the hydraulic lines into the filter housing.

[0003] IT MI20 111 315 A1 describes a filter device with 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, and wherein the valve device is movable between the open position and the closed position by means of a control device, wherein one valve device is an inflow valve.

[0004] Further filter devices are described in US 2007 / 0108119 A1 and KR 10-2012-0064955.

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

[0006] This object is achieved by a filter device having the features of patent claim 1.

[0007] At least one valve device is provided which, in an open position, enables fluid flow between one of the connection points and the filter element and, in a closed position, prevents this fluid flow; and the valve device is movable between the open position and the closed position by means of a control device. In this way, the flow of hydraulic fluid into the housing during filter element replacement 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 significantly easier. For example, no or fewer precautions need to be taken to prevent fluid from dripping from the filter housing.By arranging at least one valve in the valve housing, the amount of liquid in the filter housing that could escape when the filter housing is opened is limited or at least greatly reduced.

[0008] According to the characterizing part of claim 1, the inlet valve is arranged in the fluid flow between the inlet and an outer side of the filter element and has an inlet valve closing member formed by a cylinder wall section provided with an opening, which is movably arranged in a slot in the filter housing; and in that the opening overlaps with the inlet in the open position. The inlet valve closing member, which is slidably arranged in the filter housing, provides an inlet valve that can withstand even very high pressures.

[0009] An opening in the cylinder wall section can be in the form of a slotted hole. A slotted hole is very easy to insert into the cylinder wall section and ensures that the opening has a maximum cross-section.

[0010] Advantageously, the cylinder wall section is attached to a plate part arranged between the filter housing and the filter element; and the cylinder wall section preferably has at least one pin inserted into a hole in the plate part. The plate part acts as a transmission element to transmit movement of the control device to the inlet valve. The fact that only one pin is required, which is simply inserted into the plate part, also provides a particularly easy-to-install solution that is nevertheless sufficiently robust for daily use.

[0011] The plate part can have several, preferably kidney-shaped, openings for fluid flow between the inlet and the outside of the filter element. Thus, after passing through the inlet valve, the fluid can flow directly to the outside of the filter element.

[0012] Advantageously, the plate part has a first filter element socket into which the filter element can be screwed. Thus, the filter element can be secured to the plate part and a rotational movement of the filter element can be transmitted to the plate part.

[0013] The plate element advantageously has at least one stiffening strut on the filter element connector. The stiffening strut supports a flange portion of the plate portion and ensures the guidance of the cylinder wall section. The plate portion can have a filter housing connector, which preferably has a circumferential groove on the outer circumference, in which a sealing ring can be arranged to seal the plate portion against the filter housing. Filtrate can be safely guided from the interior of the filter element to the drain through this filter housing connector. Furthermore, the filter housing connector ensures secure guidance of the plate portion in the filter housing.

[0014] The plate part is preferably secured on its underside in the filter housing by a snap ring. This ensures that the plate part is securely held in the filter housing and cannot be pulled out of the filter housing along with the filter element.

[0015] It is particularly advantageous if a further valve device is a drain valve which is arranged in the fluid flow between an inner side of the filter element and the drain and has a drain valve closing element, preferably in the shape of a spherical segment, which comes into sealing contact with a stop, in particular on the filter housing socket, and is biased into the closed position by a spring. In this way, a separation of the fluid flow from the filter element to the drain is provided, which can be opened when required, i.e. when there is fluid pressure, and closed as soon as this pressure decreases or the pressure at the drain is higher than in the valve element. Because the drain valve closing element is in the shape of a spherical segment, it has a greater tolerance when it rests on the valve seat.Thus, the valve seat and / or the drain valve closing member can have an angle to the longitudinal axis of the filter device in the closed position and still close the drain valve securely.

[0016] The spring can be guided through a pin in the back of the filter housing. This pin can be an integral part of the filter housing, simplifying installation.

[0017] Advantageously, the drain valve closing element has a central bore into which the mandrel can be inserted, depending on the position of the drain valve closing element. This ensures secure axial guidance of the drain valve closing element when the mandrel is inserted into the central bore.

[0018] The drain valve closing element can have an axially protruding guide sleeve that rests against an outer side of the spring. This guide sleeve also serves to guide the drain valve closing element in the axial direction. Furthermore, the length prevents the spring from buckling.

[0019] Advantageously, the drain valve closing element has a stop sleeve for the spring. The spring can rest on this stop sleeve. This solution contributes to providing a particularly lightweight drain valve closing element.

[0020] The drain valve closing element can also be hollow except for the guide sleeve and / or the stop sleeve. This significantly reduces the weight of the drain valve closing element, so that a lower fluid pressure is sufficient to lift the drain valve closing element from the stop.

[0021] The drain valve closing element can be movably arranged in a cylindrical cavity of the filter housing. Therefore, no additional parts need to be provided in the filter device to guide the drain valve closing element.

[0022] The invention is explained in more detail below with reference to exemplary embodiments shown in the drawings, which are schematic and not to scale. They show: Fig. 1 to 3 show a cross-section, a side view, and an exploded view of the filter device according to the invention; Fig. 4 show a bottom view of a housing upper part; Fig. 5 show a perspective sectional view of a head part of the housing upper part; Fig. 6 to 9 show perspective views of the plate part and the cylinder wall section; Fig. 10 and 11 show a cross-section and a perspective view of the filter device in the open state; Fig. 12 to 14 show a cross-section and two perspective views of the filter device in the closed state; Fig. 15 to 17 show a cross-section, a side view, and a perspective view of a filter element; Fig. 18 and 19 show a cross-section and a perspective view of an upper end cap of the filter element; Fig. 20 to 24 show various perspective views of the lower end cap of the filter element; Fig. 25 show a perspective view of a bypass valve;26 and 27 are perspective views of a lower housing section of the filter device; Figs. 28 and 29 are detailed views of turned parts in the lower housing section; and Figs. 30 to 32 are perspective views of the lower housing section with the filter element inserted.

[0023] The Fig. 1 to 3show a filter device 10 according to the invention 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 two parts and has an upper housing part 20 and a lower housing part 22, which are screwed together via a thread 24 and sealed against each other by a seal 26. The inlet 14 and the outlet 16 are arranged in the region of a housing head 28 on opposite sides of the filter housing 12, wherein they have an axial offset V. An axial projection 32 is located on the upper side 30 of the upper housing part 20.

[0024] According to the invention, at least one valve device 34 is provided which in an open position OS ( Figs. 10, 11) 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. Furthermore, the valve device 34 is movable between the open position OS and the closed position SS by means of a control device 36, which comprises the housing lower part 22 and the filter element 18.

[0025] Such a valve device 34 is an inflow valve 38, which is in the Fig. 1 and 3 to 14 is shown in more detail. The inlet valve 38 is arranged in the fluid flow between the inlet 14 and an outer side 40 of the filter element 18 and has an inlet valve closing member 42 which is formed by a cylinder wall section 46 provided with an opening 44, which Fig. 6 to 9shown and which is movably arranged in a semicircular slot 48 in the filter housing 12. The opening 44 of the cylinder wall section 46 is in the open position OS in overlap with a housing bore 50 of the inlet 14. The upper housing part 20 has the housing bore 50 on both sides of the slot 48, which allows a fluid flow from the inlet 14 into the interior 52 of the filter housing 12 in the open position OS of the inlet valve 38. The opening 44 in the cylinder wall section 46 has the shape of an elongated hole and is larger than the housing bore 50 of the inlet 14. The cylinder wall section 46 has the opening 44 in the side view ( Fig. 6 and 9 ) closer to its left end 54. Adjacent to the opening 44, a pin 58 is provided on an underside 56 of the cylinder wall portion 46, which pin is inserted into a hole 60 in a plate part 62.

[0026] The plate part 62 has several, preferably kidney-shaped openings 64 for the fluid flow between the inlet 14 and the outer side 40 of the filter element 18. Furthermore, the plate part 62 has on its underside 66 a filter element socket 68 into which the filter element 18 can be screwed. For this purpose, an internal thread 70 is provided. As can be seen in the Figs. 8 and 9 As can be seen, the filter element socket 68 is supported relative to a flange 72 of the plate part 62 by stiffening struts 74. The stiffening struts 74 are arranged offset on a pitch circle and reinforce a web 76 between the ends of the openings 64 of the plate part 62. On the upper side 78, the plate part 62 has a filter housing socket 80, which has a circumferential groove 82 on the outer circumference, in which a sealing ring 84 is provided for sealing the plate part 62 relative to a receiving socket 86 arranged in the filter housing 12. As can be seen particularly in the Fig. 1 and 10 to 14As can be seen, the plate part 62 in the filter housing 12 is placed against the receiving socket 86 and is held on the underside 66 by a snap ring 90 which is inserted into a circumferential groove 92 in the filter housing 12.

[0027] A further valve device 34 is a drain valve 94, which is arranged in the fluid flow between an inner side 96 of the filter element 18 and the outlet 16 and has a spherical segment-shaped drain valve closing member 98, which sealingly bears against a stop 100 on the filter housing socket 80 of the plate part 62 and is biased into the closed position SS by a spring 102. The spring 102 is guided at the rear by a mandrel 104 of the filter housing 12. The drain valve closing member 98 has a central bore 106, into which the mandrel 104 can be inserted depending on the position of the drain valve closing member 98, as can be seen in particular in the Figs. 10 and 11can be seen. The drain valve closing member 98 has a guide sleeve 107 projecting axially in the direction of the mandrel 104, which rests against an outer side 108 of the spring 102. Furthermore, the drain valve closing member 98 has a stop sleeve 110 for the spring 102. In order to make the drain valve closing member 98 as light as possible, it is made of a material other than the guide sleeve 106 and the stop sleeve 110 as well as a stiffener 111 ( Fig. 13 ) hollow. The drain valve closing member 98 is movably arranged in a cylindrical cavity 112 of the filter housing 12. The drain 16 extends radially away from this cavity 112.

[0028] In the Figs. 10 and 11The filter device 10 is shown with the valve devices 34 in the respective open position OS. It can be seen that the opening 44 of the cylinder wall section 46 of the inlet valve 38 overlaps the bore 50 of the inlet 14. The cylinder wall section 46 was rotated into this position when the filter element 18 was screwed into the plate part 62. Due to the resistance of the cylinder wall section 46, the open position OS is only reached when the filter element 18 has already been completely screwed into the plate part 62. If a fluid flow then occurs between the inlet 14 and the outlet 16, the unfiltered liquid flows from the inlet 14 through the inlet valve 38 and the kidney-shaped openings 64 in the flange 72 of the plate part 62 to the outer side 40 of the filter element 18, through a filter medium 114 of the filter element 18 to its inner side 96 and from there filtered through the central opening 116 of the plate part 62 to the outlet valve 94.When the pressure is sufficiently strong, the drain valve closing member 98 is lifted from its valve seat 100 and the filtered liquid can flow to the drain 16.

[0029] In the Fig. 12 to 14 the filter device 10 with the valve devices 34 is shown in the closed position SS. In the closed position SS, the connection from the inlet 14 to the interior 102 of the filter housing 12 is interrupted by the cylinder wall section 46. The outlet valve closing member 98 also rests against its valve seat 100. If the lower housing part 22 is unscrewed from the upper housing part 20, the filter element 18 is also rotated. Due to the screw connection of the filter element 18 and the plate part 62, the plate part 62 and the cylinder wall section 46 are also initially rotated until the cylinder wall section 46 at one end 118 ( Fig. 4) of its housing slot 48. Only then is the filter element 18 unscrewed from the plate part 62. Only after the filter element 18 has been completely unscrewed from the plate part 62 can the lower housing part 22 be completely unscrewed from the upper housing part 20.

[0030] The further construction of the filter device 10 below the plate part 62 is known in principle from the subsequently published DE 10 2020 004 489 and is therefore described below with reference to the Fig. 1 to 3 and 15 to 32 only described in overview.

[0031] The filter element 18 comprises the filter medium 114, which is arranged between an upper end cap 120 and a lower end cap 122 and is enclosed by them. A cylindrical support tube 124 is provided on an inner side 96 of the filter medium 114. The upper end cap 120 has four projections 126 on its circumference, which are evenly offset on a pitch circle and are intended to facilitate the handling of the filter element 18 when removing it from the housing base 22. A threaded connector 128 with an external thread 130 is provided on the upper end cap 120, which Figs. 18 and 19 is shown in more detail. The lower end cap 122 of the filter element 18 is constructed in several parts, with a surround ring 132 surrounding the filter element 18 and holding a bypass valve 134. The bypass valve 134 is replaceably inserted into the surround ring 132. This has a cage 136 with windows 138 in which a coarse-mesh filter fabric 140 is provided, as can be seen in Fig. 25can be seen. The bypass valve 134 has a bypass valve closing member 142, which is biased into a closed position SS by a spring 144. The bypass valve closing member 142 is T-shaped in cross-section and rests against a valve seat 146 in the cage 136.

[0032] A fastening ring 150 is connected to this edging ring 132 via four S-shaped spring bands 148. The fastening ring 150 has a larger diameter than the edging ring 132. The fastening ring 150 can be inserted into the lower housing part 22 and fastened there in a locking manner. For this purpose, the fastening ring 150 has a flange 152 and a connecting piece 154 extending axially downward from the flange 152. The connecting piece 154 is provided on the outside with a locking collar 156, via which the filter element 18 can be releasably secured in the lower housing part 22 in a recess 158, which has an inwardly drawn-in detent 162 at an upper end 160. On the flange 152, four drivers 164 are arranged - also evenly offset on a pitch circle - which have inclined surfaces 166 and vertically extending contact surfaces 168, which can engage with rotating parts 170 on the housing base 22. The rotating parts 170 are in the Fig. 26 to 29and also have a shape with an inclined surface 172 and a vertical surface 174, so that the drivers 164 and the rotating parts 170 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.

[0033] The lower housing part 22 is secured to the main housing part 20 via the thread 24. The filter element 18 has an additional thread 130 for attachment to the plate part 62. The thread pitches of these two threads 24, 130 differ to ensure that when the lower housing part 22 is unscrewed, the filter element 18 is first unscrewed from the plate part 62 before being unscrewed together with the lower housing part 22 from the upper housing part 20. The spring elements 148 between the lower end cap parts 132, 150 are provided to allow length compensation. When screwing in the filter element 18, the procedure is reversed. First, the spring element 148 is screwed into the plate part 62 and then the lower housing part 22 is finally screwed onto the upper housing part 20.

[0034] The filter housing 12, the filter element 18, the plate part 62 and the drain valve 98 are arranged coaxially to the longitudinal axis LA.

[0035] The functionality of the filter device is described below.

[0036] When the lower housing part 22 is unscrewed from the upper housing part 20, the filter element 18 in the filter housing 12 is rotated along with it. In a first phase, the plate part 62 is also rotated together with the inlet valve closing element 46 until it comes into contact with one end 118 of the housing slot 48. This contact prevents the plate part 62 from being rotated any further. This makes it possible, in a second phase, to unscrew the filter element 18 from the plate part 62 while the filter housing 12 remains closed to the outside. As the filter element 18 is unscrewed from the plate part 62, the spring elements 148 compress and thus enable length compensation. The lower housing part 22 is then completely unscrewed from the upper housing part 20, with the filter element 18 remaining securely fastened to the lower housing part 22. Finally, the filter element 18 can be removed from the lower housing part 22 and replaced with a new filter element 18.

[0037] When installing a new filter element 18, it is inserted into the lower housing part 22 and pushed into the upper housing part 20. The lower housing part 22 is then screwed onto the upper housing part 20, whereby the filter element 18 is rotated and screwed into the plate part 62. By screwing in the filter element 18, the inlet valve 38 is moved into the open position. When the filter element 18 is fully screwed into the plate part 62, the drivers 164 and the rotating parts 170 on the lower end cap 122 and on the lower housing part 22 can slide against each other via their respective inclined surfaces 164, 172, so that the lower housing part 22 can be fully screwed on without the filter element 18 rotating any further.

[0038] The filter device 10 according to the invention provides a solution for effectively separating an interior 102 of a filter housing 12 from an inlet 14 and an outlet 16 by means of valve devices 34 when the filter housing 12 is unscrewed to replace the filter element 18. This has no equivalent in the prior art.

[0039] 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 10 may be arranged at an angle to the vertical.

Claims

1. Filter apparatus 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 (34) 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, and wherein the valve device (34) is movable between the open position (OS) and the closed position (SS) by means of an actuating device (36), wherein the one valve device (34) is an inflow valve (38), characterised in that, the inflow valve 38 is arranged in the fluid flow between the inlet (14) and an outer side (40) of the filter element (18) and has an inflow valve closing member (42) which is formed by a cylinder wall portion (46) that is provided with an opening (44) and which is arranged so as to be movable in a slot (48) in the filter housing (12); and in that, in the open position (OS), the opening (44) overlaps the inlet (14).

2. Filter apparatus according to claim 1, characterised in that the opening (44) in the cylinder wall portion (46) has the shape of an elongated hole.

3. Filter apparatus according to claim 1 or 2, characterised in that the cylinder wall portion (46) is attached to a plate member (62), which is arranged between the filter housing (12) and the filter element (18); and in that the cylinder wall portion (46) preferably has at least one pin (58), which is inserted into a hole (60) in the plate member (62).

4. Filter apparatus according to claim 3, characterised in that the plate member (62) has a plurality of, preferably kidney-shaped, openings (64) for the fluid flow between the inlet (14) and the outer side (40) of the filter element (18).

5. Filter apparatus according to claim 3 or 4, characterised in that the plate member (62) has a first filter element connector (68) into which the filter element (18) can be screwed.

6. Filter apparatus according to one of claims 3 to 5, characterised in that the plate member (62) has at least one reinforcement strut (74) on the filter element connector (68).

7. Filter apparatus according to one of claims 3 to 6, characterised in that the plate member (62) has a filter housing connector (80), which preferably has a circumferential groove (82) on the outer circumference, in which a sealing ring (84) can be arranged for sealing the plate member (62) with respect to the filter housing (12).

8. Filter apparatus according to one of claims 3 to 7, characterised in that the plate member (62) is fixed in the filter housing (12) on an underside (66) by a circlip (90).

9. Filter apparatus according to one of the preceding claims, characterised in that a further valve device (34) is a discharge valve (94), which is arranged in the fluid flow between an inner side (96) of the filter element (18) and the outlet (16) and has a discharge valve closing member (98), preferably shaped like a spherical segment, which comes into sealing contact against a limit stop (100), in particular against the filter housing connector (80), and is urged into the closed position (SS) by a spring (102).

10. Filter apparatus according to claim 9, characterised in that the spring (102) is guided at the rear by a mandrel (104) of the filter housing (12).

11. Filter apparatus according to claim 10, characterised in that the discharge valve closing member (98) has a central bore (106) into which the mandrel (104) can be inserted depending on the position of the discharge valve closing member (98).

12. Filter apparatus according to one of claims 9 to 11, characterised in that the discharge valve closing member (98) has an axially protruding guide sleeve (107) which bears against an outer side (108) of the spring (102).

13. Filter apparatus according to one of claims 9 to 12, characterised in that the discharge valve closing member (98) has a stop sleeve (110) for the spring (102).

14. Filter apparatus according to claim 12 or 13, characterised in that the discharge valve closing member (98) is hollow except for the guide sleeve (107) and / or the stop sleeve (110).

15. Filter apparatus according to one of claims 9 to 14, characterised in that the discharge valve closing member (98) is arranged so as to be movable in a cylindrical cavity (112) of the filter housing (12).