Filter apparatus and filter element

Abstract

The invention relates to a filter apparatus comprising: a filter housing (10) at least consisting of a housing upper part (12) and a housing lower part (14), which is provided for exchangeably receiving a filter element (16) at least partly; and a control device (22) for controlling fluid flows in the housing upper part (12), which control device, in a blocking position, blocks a fluidic connection between a fluid inlet (24) and a fluid outlet (26) and, in an unblocking position, unblocks said fluidic connection, wherein, by means of an actuation device (44) on the filter element, the control device (22) can be controlled such that, when the housing lower part (14) is disconnected from the housing upper part (12), the control device (22) moves into the blocking position and, when the housing lower part (14) is attached to the housing upper part (12), the unblocking position is established, characterized in that the control device (22) comprises a rotary slide housing (46) with at least one coupling element (48, 50), which cooperates with corresponding coupling elements (54, 56, 58, 60) on the filter element (16) as the actuation device (44) so as to form at least one coupling (52, 53), such that, when the housing lower part (14) is attached or removed, each coupling element (48, 50) of the rotary slide housing (46) is drivingly contacted by at least one of the corresponding coupling elements (54, 56, 58, 60) associable therewith and is moved by said at least one of the corresponding coupling elements from the blocking position into the unblocking position or vice versa, with subsequent release of the relevant coupling (52, 53) as soon as one of the positions is assumed by the rotary slide housing (46).

Description

[0001] Filter device and filter element

[0002] The invention relates to a filter device with a filter housing at least consisting of an upper housing part and a lower housing part, which is intended to at least partially accommodate a filter element in an exchangeable manner and with a control device for controlling fluid flows in the upper housing part, which in a blocking position separates a fluid-carrying connection between a fluid inlet and a fluid outlet and releases this in a release position, wherein by means of an actuating device on the filter element the control device can be controlled in such a way that when the lower housing part is separated from the upper housing part, the control device reaches the blocking position, and when the lower housing part is attached to the upper housing part, the release position is established.

[0003] The invention further relates to a filter element, in particular intended for use in such a filter device.

[0004] DE 10 2021 002 511 A1 discloses a filter device with a filter housing that has at least two connection points, such as an inlet for unfiltered material and an outlet for filtrate, and accommodates a replaceable filter element. A valve device is provided as the control device, 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. Furthermore, the valve device can be moved back and forth between the open position and the closed position by means of an actuating device on the filter element. The valve device has a spring-loaded inlet valve, which is arranged in the fluid flow between the inlet and an outer side of the filter element, and a spring-loaded outlet valve, which is arranged in the fluid flow between an inner side of the filter element and the outlet.

[0005] From DE 10 2021 002 024 A1 a comparable filter device together with an associated filter element is known, wherein an 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 as a control device, which is formed by a cylinder wall section provided with an opening, which is movably guided in a slot in the filter housing with its opening in the open position of the control device overlapping with the inlet.

[0006] When installing the filter element in the filter device, it is first inserted into a lower housing section and then pushed into the upper housing section of the filter device. The lower housing section is then screwed onto the upper housing section, whereby the inserted filter element rotates with it and the inlet valve is moved into the open position. Once the filter element is fully screwed in and thus secured to the upper housing section, corresponding coupling elements on the lower end cap of the filter element and on the base of the lower housing section can slide off each other over their respective inclined surfaces, creating a type of ratchet coupling and allowing the lower housing section to be fully screwed onto the upper housing section to maintain an operating position without the filter element rotating any further.

[0007] Based on this prior art, the invention is based on the object of further improving the known solutions in such a way that it is possible to control fluid flows in the context of hydraulic devices in a particularly functionally reliable manner.

[0008] A filter device having the features of patent claim 1 and a filter element having the features of patent claim 1 solve this problem.

[0009] Because according to the characterizing part of patent claim 1 it is provided according to the invention that the control device has a rotary valve housing with at least one coupling element, which cooperates to form at least one coupling with corresponding coupling elements on the filter element as the actuating device in such a way that when the lower housing part is attached or removed at least one of the corresponding coupling elements comes into driving contact with the respective assignable coupling element of the rotary valve housing and this moves from the locked position into the released position or vice versa, with subsequent release of the respective coupling as soon as one of the positions is assumed by the rotary valve housing, all essential operating elements for actuating the control device are realized between the rotary valve housing and the adjacent end of the filter element, which benefits functional reliability.Furthermore, this arrangement can be implemented in a particularly space-saving manner. There is also a direct force input between the filter element's actuating device and the adjacent rotary valve housing, which serves as the control device, allowing for unhindered actuation. Furthermore, spring-loaded valves, which are inherently prone to failure, can be dispensed with in the implementation of the control device. This allows for particularly reliable control of fluid flows from hydraulic devices that are connected to the filter device and / or the filter element.

[0010] In a particularly preferred embodiment of the filter device according to the invention, the respective coupling, designed in the manner of a ratchet coupling, has two adjacent, opposing pairs of spring tongues as corresponding coupling elements on an end cap of the filter element, which protrude resiliently into a movement path of at least one control cam as the one coupling element of the rotary valve housing. Thus, the respective control cam of the rotary valve housing forms the respective coupling element, and the adjacent, opposing pairs of spring tongues form the corresponding coupling elements on the filter element.Because, contrary to the prior art, the ratchet coupling is relocated from the bottom of the filter element to its head side and no longer interacts with the lower housing section, but rather with the rotary valve housing in the upper housing section, the lower housing section as a whole can form an outwardly closed filter bowl which is screwed as a whole to a filter head as the upper housing section in the operating position. Segmenting the filter bowl into a part that is an integral part of the filter head and a further part for carrying out the rotary movement for the filter element via the ratchet coupling on the bottom is thus avoided, so that the design of the filter device as a whole is simplified and can therefore be implemented cost-effectively. The necessary sealing between the filter bowl and filter head is also simplified, as is the disassembly of the filter bowl from the filter head and its reattachment.In a further preferred embodiment of the filter device according to the invention, it is provided that the rotary valve housing has two fluid passages and two shut-off walls which can be brought into alignment with the fluid supply and discharge in the release and blocking positions, respectively.

[0011] This ensures that both the fluid inlet and outlet are shut off during an element change by means of the rotary valve housing at a central location in the filter head, thus increasing functional reliability. This also leads to a desirable increase in pressure loss if no filter element is installed in the device, which is often due to an oversight and can be detected.

[0012] In a further preferred embodiment of the filter device according to the invention, the rotary valve housing has a further control cam, which is guided in a slotted guide in the upper housing section and limits the movement of the rotary valve housing between the locking and release positions. Thanks to the slotted guide, the position of the rotary valve housing is secured in its end positions, thus preventing malfunctions.

[0013] In a further particularly preferred embodiment of the filter device according to the invention, provision is made for a carrier to exist between the filter element and the lower housing part, which, during a relative movement between the stationary upper housing part and the movable lower housing part, carries the filter element accommodated in the lower housing part in the same direction. By coupling the filter bowl as the lower housing part to the filter element via a corresponding carrier, both a force-locking and a form-locking connection is achieved, which enables secure rotational carriage for the filter element both when screwing the filter bowl onto or unscrewing it from the filter head, so that the actuating device always correctly actuates the control device.

[0014] In a further preferred embodiment of the filter device according to the invention, the rotary valve housing has an annular seal on the fluid outlet side in the housing upper part, which, in the release position, seals the fluid transition between the fluid outlet and an internal fluid guide in the rotary valve housing. It will be surprising to a person of ordinary skill in the art that only one annular seal on the outlet side of the filter device is sufficient, eliminating the need for additional sealing devices, particularly on the inlet side. Thus, a seal on the outlet side, with the lower fluid pressure compared to the inlet side of the filter device, is sufficient.

[0015] In a further preferred embodiment of the filter device according to the invention, the inner fluid guide extends through the rotary valve housing at a right angle and has a connection bevel for the fluid-carrying connection of the filter element on its inner side at its free end facing away from the fluid outlet. Thanks to the fluid guide at a right angle, flow losses and cavitation are avoided, and thanks to the predeterminable geometry of the connection bevel, a type of copy protection is achieved, ensuring that only original, high-quality filter elements can be used as replacement elements in the filter device.

[0016] In a further preferred embodiment, the rotary valve housing has a further internal fluid guide, which, in the release position, establishes a fluid-conducting connection between the fluid inlet and a fluid chamber formed by the filter element and the housing base in an operating position. This allows an inclined plane to be achieved on the fluid supply side, i.e., on the dirt side, within the rotary valve housing in the filter head, which in turn helps prevent flow losses and cavitation.

[0017] In a further particularly preferred embodiment of the filter device according to the invention, the rotary valve housing comprises at least one safety valve which, when fluid flows through the rotary valve housing in its blocking position, opens from the fluid inlet to the fluid outlet and releases the corresponding fluid path, bypassing the fluid chamber in the lower housing section. Preferably, a contamination indicator is connected to the corresponding fluid path. This ensures that, in the event of inadvertent flow through the filter device without a filter element inserted, a preload valve forming the safety valve is actuated via safety passages in the rotary valve housing. This preload valve opens at a set preload pressure and establishes a fluid safety connection between the inlet and outlet without dangerous pressure buildup.If a clogging indicator, preferably in the form of a differential pressure indicator, is connected to the relevant fluid path, any incorrect operation can be detected by this clogging indicator. This allows the absence of the filter element in the operating position of the filter device to be reliably detected and thus prevented. The technical design of such clogging indicators is shown by way of example in DE 10 2014 014 37 A1 of the patent holder, so it will not be discussed further here.

[0018] Preferably, it is further provided that at least one bypass valve is accommodated in the rotary valve housing. In the release position, this bypass valve, when the filter element reaches a predefined level of contamination, opens the fluid path between the fluid inlet and outlet during operation, bypassing the filter element. This ensures the proper functioning of a hydraulic system connected to the filter device, which is supplied with fluid at a predefined pressure even when the filter element is clogged or blocked.

[0019] The object of the invention relating to improved control of fluid flows within hydraulic devices in a functionally reliable manner is also achieved by a filter element having the features of patent claim 11. Due to the fact that the filter element with its element material, which has an end cap on at least one free end face, has, according to the invention, individual coupling elements on this end cap which protrude outwards as part of at least one coupling, an actuating device is created on the head side directly on the filter element, by means of which it is possible, via further coupling elements on a control device of a filter device, to control the fluid flows between a fluid inlet and an outlet in a functionally reliable manner.In particular, the interaction of the actuating device on the filter element with the control device on a filter housing of the filter device ensures that the filter device cannot be started if the filter element is missing. This prevents incorrect operation and ensures the safe control of fluid flows in a hydraulic system that is connected to the filter element.

[0020] Preferably, the coupling elements of the end cap are formed from at least one pair, preferably two pairs, of adjacent, opposing spring tongues, each of which protrudes inward by a predeterminable distance along a movement path. Thus, essential components are provided in a type of ratchet coupling on the filter element, which ensures that the control device in the form of a rotary valve housing continues to be regularly actuated, even if the filter element has not yet been completely removed or inserted into its operating position.

[0021] The movement path is preferably limited by shell-like guide surfaces as part of the respective coupling, which protrude beyond the associated end cap and are each limited at the end by a spring tongue. The combination of the movement path with elastically flexible spring tongues ensures, on the one hand, secure guidance of the coupling elements of the rotary valve housing and the filter element, which can be coupled together, and, on the other hand, deactivation of the actuating device as soon as the rotary valve housing is in its respective locking or releasing position in the filter housing.

[0022] In a further particularly preferred embodiment of the filter element according to the invention, the shell-like guide surfaces are surrounded on the outside by a retaining ring which, viewed in the axial direction, projects at least partially beyond the guide surfaces and which is firmly connected, preferably in one piece, to the associated end cap via webs. The retaining ring preferably projects beyond the edge of the end cap and has at least one projecting catch in the direction thereof. In this way, a force- and form-fitting fastening option is created via the retaining ring and its catch, and the coupling elements on the filter element are also protected from mechanical damage. The combination of the retaining ring with the coupling elements also achieves a rigid, in-house construction for the filter element via the associated end cap.

[0023] In a particularly advantageous manner, a joint shell is pivotably inserted into a central opening in the end cap, said joint shell having a connection point that can be tilted in predeterminable directions to form a fluid guide to the inside of the filter element. While the retaining ring provides a rigid connection option for receiving the filter element, a central fluid guide starting from the interior of the filter element can be achieved in a sealed manner via the movable, in particular tiltable, connection point. It will be surprising to a person of average skill in the art that he can achieve a stationary, secure positioning of the filter element as a whole via the retaining ring and, in the process, obtain variability in the fluid guide via the joint shell, which also has the advantage that any tolerance differences between the element holder and the fluid guide can be immediately compensated.

[0024] In a particularly space-saving manner, it is provided that end parts of the element material enclose the joint shell in a receptacle of the end cap, so that the joint shell is also supported on the outside by the element material and thus an unhindered adjustment of the joint shell with its connection point is possible in that it can be brought into the fluid-carrying operating position without force.

[0025] The filter device according to the invention is explained in more detail below using an exemplary embodiment as shown in the drawing. The drawings show, in a schematic representation and not to scale, the

[0026] Figure 1 shows, in the form of a longitudinal section, the filter device as a whole with the fluid inlet arranged on the left and the fluid outlet arranged on the right, as viewed in the direction of the figure;

[0027] Figure 2 shows an image section of the upper part of the filter device according to Figure 1, rotated by 180° around the longitudinal axis of the filter device, with the fluid inlet and the fluid outlet now arranged on the right and on the left, which are connected to one another in a fluid-conducting manner in the release position shown;

[0028] Figure 3 is a representation corresponding to Figure 2, in which the fluid-carrying connection between the fluid inlet and the fluid outlet is now separated in a blocking position;

[0029] Figure 4 shows a representation corresponding to Figure 3 with the filter element removed and with a safety valve open;

[0030] Figure 5 shows a section of the image in which a coupling element of a rotary valve housing in the upper part of the housing is in contact with corresponding coupling elements on an end cap of the filter element to establish a coupling connection;

[0031] Figure 6 shows the coupling engagement according to Figure 5 in plan view with two opposing coupling elements of the rotary valve housing together with associated pairs of corresponding coupling elements on an end cap of the filter element;

[0032] Figure 7 shows the cap design of the end cap according to Figure 6 relating to the filter element according to Figures 1 to 3;

[0033] Figure 8 shows a longitudinal section through the end cap shown in Figure 7; Figure 9 shows, in the form of an exploded view, parts of the rotary valve housing with adjacent parts of a housing base with the filter element inserted, together with the associated upper end cap;

[0034] Figure 10 shows an inclined view of the rotary valve housing according to Figure 9; and

[0035] Figures 11 and 12 show, once in a longitudinal section and once in a bottom view, individual components of the rotary valve housing according to Figures 9 and 10.

[0036] The filter device shown in Figure 1 has a filter housing 10, consisting of an upper housing part 12 and a lower housing part 14, which are also technically referred to as a filter head or filter bowl. The lower housing part 14 is designed to accommodate a replaceable filter element 16. The upper housing part 12 is usually arranged stationary or fixed within the framework of an overall hydraulic arrangement, and the lower housing part 14 can be firmly connected to the upper housing part 12 in a releasable manner via a threaded section 18. In particular, the lower housing part 14 can be screwed into an internal thread of the upper housing part 12 in a releasable manner, forming the threaded section 18 with an associated external thread.As viewed in the direction of Figure 1, a circumferential annular groove 20 is arranged above the external thread of the lower housing part 14, which is intended to accommodate an annular seal (not shown) in order to seal the interior of the filter device from the environment at this point. A control device 22 is accommodated in the upper housing part 12 for controlling fluid flows in the upper housing part 12, wherein the control device 22 separates a fluid-carrying connection between a fluid inlet 24 and a fluid outlet 26 in a blocked position as shown in Figure 3 and releases this connection again in the released position shown in Figure 1. Both the fluid inlet 24 and the fluid outlet 26 are connected to the (overall) hydraulic device via conventional piping (not shown).In this way, fluid, for example in the form of a hydraulic medium, can be cleaned of particulate contaminants using the filter device according to Figure 1. For this purpose, unfiltered fluid flows via the fluid inlet 24 into a hollow cylindrical fluid chamber 28, which is bounded on the outer circumference by the cylindrical inner wall of the housing base 14 and by the outer circumferential shell of the regularly pleated filter element 16.

[0037] The unfiltered material flow then travels from the fluid chamber 28 from the outside to the inside and, upon flowing through the cleaning element material 30, to the inside 32 of the filter element 16. As the element material 30 flows through the latter, it is supported along the outer surface of a hollow cylindrical support tube 34, the fluid passages 36 of which are only partially shown in Figure 1. The element material 30 removes particulate contamination, if present, from the fluid flow, so that the inside 32 of the filter element 16 forms the so-called filtrate side of the filter device during operation. Via a perpendicular internal fluid guide

[0038] 38 in the control device 22, the cleaned fluid then passes into the fluid outlet 26 for further use. A further internal fluid guide

[0039] 39 is thus formed by the fluid path from the inlet 26 into the fluid chamber 28 with the filter element 16. The element material 30 of the filter element 16 is accommodated, as shown in Figure 1, between an upper end cap 40 and a lower end cap 42. These end caps 40, 42 serve in the usual manner as end enclosures for the free end faces of the element material 30. The specific construction of the upper end cap 40 will be explained in more detail below; the lower end cap 42 is supported in the usual manner on the pot or bottom side of the lower housing part 14 or the filter pot.

[0040] The upper end cap 40 has an actuating device 44 by means of which the control device 22 can be controlled in such a way that when the lower housing part 14 is separated from the upper housing part 12, the control device 22 moves into the locking position and when the lower housing part 14 is attached to the upper housing part 12, the release position according to Figure 1 is established.

[0041] The illustration in Figure 2 shows the upper housing section 12 in a view rotated by 180° relative to the longitudinal axis of the filter device, with the fluid inlet 24 now located on the right, as viewed in Figure 2, and the fluid outlet 26 on the left. Otherwise, the components shown in Figure 2 correspond to the solution shown in Figure 1.As Figure 2 further shows, the control device 22 has a rotary valve housing 46 with two coupling elements 48, 50 which are diametrically opposed to one another with respect to the aforementioned longitudinal axis and which cooperate to form two couplings 52, 53 with corresponding coupling elements 54, 56, 58, 60 on the filter element 16 as the actuating device 44 in such a way that when the housing lower part 14 is attached or removed, at least one of the corresponding coupling elements 54, 56, 58, 60 on the filter element 16 comes into driving contact with the respective associated coupling element 48, 50 of the rotary valve housing 46 and this moves from the blocking position according to Figure 3 into the release position according to Figures 1 and 2 or vice versa, upon subsequent release of the respective coupling 52, 53 as soon as one of the positions is assumed by the rotary valve housing 46 is.

[0042] The respective coupling solution on the upper end cap 40 can be seen in particular in Figure 7. Starting from the fluid-permeable center of the upper end cap 40, there are two axially upwardly projecting half-shells 62, 64, which are preferably an integral part of the upper end cap 40, which can be manufactured, for example, by a plastic injection molding process or by 3D printing. The two half-shells 62, 64 each have a corresponding coupling element 54, 60 or 56, 58 at their free, opposite ends. Thus, the adjacent corresponding coupling elements 54 and 56 or 58 and 60 are part of the respective coupling 52 or 53. The respective corresponding coupling element 54, 56, 58 and 60 is formed from a resiliently flexible spring tongue which has an inwardly projecting locking lug 66 at its free end.The respective spring tongue with its locking lug 66 is formed by a bottom-side recess 68 in the respective half-shell 62, 64, in the manner of a bottom-side cutout opposite the upper side 70 of the upper end cap 40, which, in the operating position of the filter device, essentially extends horizontally as a continuous surface. As viewed in the direction of Figure 7, the spring tongues with their projecting locking lugs 66 project inward by a predeterminable distance along a circular movement path 72, which is also delimited by the inner guide surfaces 74 of the half-shells 62, 64.

[0043] If the lower housing part 14 is screwed counterclockwise from below onto the upper housing part 12 as viewed in the direction of Figures 5 and 6, and the control device 22 or the rotary valve housing 46 is in its position blocking the fluid-carrying connection between the inlet 24 and outlet 26 according to Figure 3, the locking lugs 66 of the corresponding, diametrically opposed coupling elements 54, 58 of the two half-shells 62, 64 take along the adjacent opposing coupling elements 48 and 50 of the control device 22 as soon as these engage with one another from below during the screwing-on process, and in doing so rotate the rotary valve housing 46 into its release position according to Figures 1 and 2.If the rotary valve housing 46 is pivoted into its corresponding release position, but the housing lower part 14 with the filter element 16 may not yet be fully screwed on, the respective coupling 52, 53 functions as a ratchet coupling, and the coupling elements 48, 50, which are in their one end position, are overrun by the corresponding coupling elements 54, 60; 56, 58 without triggering further actuation. Accordingly, when the housing lower part 14 is further screwed on, the control device 22 or the rotary valve housing 46 remains in the assumed release position shown in Figures 1 and 2.

[0044] If, for an example of replacing a used filter element 14 with a new element, the lower housing part 14 is now unscrewed from the upper housing part 12 in a clockwise direction against the previously described direction of rotation, the locking lugs 66 of the corresponding coupling elements 56, 60, possibly only after overrunning the ratchet coupling 52, 53, now come into contact with the control cams or coupling elements 48, 50 of the rotary slide housing 46, which are diametrically opposite one another to the longitudinal axis of the device, and bring this from its release position according to Figures 1, 2 into the shut-off position for the fluid guide according to Figure 3. The specified Figures 5 and 6 show the possible rotational state when the rotary slide housing 46 is to move from its blocking position into its fluid-conducting initial or release position.

[0045] As can be seen in particular from Figures 2 and 3, the rotary slide valve housing 46 is designed in the manner of a shut-off valve or a plug in a changeover valve and, in addition to two fluid passage points 76, 78 (Figure 2), also has two shut-off walls 80, 82 (Figure 3), which can be brought into alignment with the fluid inlet 24 and the fluid outlet 26 in the release position and the blocking position, respectively. The two opposing arrow representations in Figure 3 in the inlet 24 and in the outlet 26 symbolize that in both possible fluid flow directions the filter element 16 is in any case separated from the corresponding fluid guide in the blocking position.

[0046] As can also be seen from Figures 2 and 9 to 11, the rotary valve housing 46, as viewed in the direction of the aforementioned figures, has a further cylindrical control cam 84 on the head side, which is an integral component of the rotary valve housing 46 and is supported on the circumference by a type of central or spring centering 86. This further control cam 84 is guided in an associated slotted guide 88 (Figure 2) in the upper housing part 12 in such a way that the possible travel movements of the rotary valve housing 46 between the locked position according to Figure 3 and the released position according to Figure 2 are limited in both pivoting directions. This prevents the rotary valve housing 46 from being inadvertently driven continuously via the respective coupling 52, 53 and thus reaching unwanted intermediate positions if relative movements occur between the lower housing part 14 and the upper housing part 12 due to screwing or unscrewing processes.As can be further seen from Figures 2, 3, 10, and 12, the rotary valve housing 46 has an annular seal on the side of the fluid outlet 26 in the upper housing section 12. This seal is not shown in detail, but rather only the corresponding receptacle 90 for such an annular seal. Since the annular seal has to cover several fluid openings, which will be explained in more detail below, the corresponding annular receptacle 90 is provided with rectilinear intermediate sections 92 between the adjacent curves 94, creating a kind of flattened sealing oval.

[0047] As shown in particular in Figure 4, which shows the filter device in its blocked position and without the filter element 16 inserted in the pot-shaped housing lower part 14, a possible fluid path is open between the fluid inlet 24 and the fluid outlet 26, which is indicated in Figure 4 by a flow arrow that shows the possible fluid path. For this fluid guidance, the two diametrically opposed shut-off walls 80, 82 each have an additional fluid opening 96 and 98, respectively, through which the possible fluid flow from the fluid inlet 24 passes via the facing fluid opening 96 of the first shut-off wall 80 into the interior of the rotary valve housing 46 and from there via the further fluid opening 98 in the shut-off wall 82 to the side with the fluid outlet 26.In this respect, the rotary valve housing 46, which is designed in the manner of a hollow chamber construction, is equipped with a corresponding free fluid path between the support chamber walls in the interior of the rotary valve housing 46.

[0048] Furthermore, according to the sectional view through the rotary valve housing 46 in Figure 11, two safety valves 100 are located within the possible fluid path shown in Figure 4. Each safety valve 100 is designed as a so-called double valve, i.e., each safety valve 100 also functions as a bypass valve 102. For this purpose, each valve 100, 102 has associated pairs of closing parts 104 and 106, respectively, which are assigned to each other in pairs and each supported by a coupling spring 108 designed as a compression spring. Accordingly, both a safety valve function and a bypass function can be performed with just one valve construction.A preload pressure can be specified for the respective valve function via the coupling spring 108. If the pressure at the fluid inlet 24 exceeds a preset threshold value, the two associated safety valves 100 open, one of which is only partially shown in Figure 4. Accordingly, in the event of an unlawful flow through the filter device without a filter element 16 via the aforementioned safety bores in the form of the additional fluid openings 96, 98 in the rotary valve housing 46, the respective preload or safety valves 100 are opened with the bypass valves 102 closed, thus preventing an unacceptably high fluid pressure from building up on the inlet side 24 of the filter device.

[0049] A clogging indicator 110 is screwed into the upper housing section 12 from above. This clogging indicator is designed as a differential pressure gauge for measuring the differential pressure and measures the differential pressure via two fluid channels 112. One fluid channel 112 leads to the inside of the upper housing section 12, in which the rotary slide housing 46 is pivotally guided, and the other fluid channel 112 opens into the fluid outlet 26 as shown in Figure 4. The set preload pressure, exceeding which can be detected by the differential pressure or clogging indicator 110, thus prevents incorrect operation of the filter device, i.e. operation of the filter device without the filter element 16 can be ruled out.As can be seen in particular from Figure 10, the fluid passage point 78 and the additional fluid opening 98 in the barrier wall 82 are in any case enclosed at the edges by the oval ring seal in the associated receptacle 90 and are thus sealed off from the environment.

[0050] If the filter device is in its filtering operating position according to Figure 2 and a so-called blocking of the filter element 16 with particulate contamination occurs, the bypass valves 102 open, bypassing the fluid chamber 28 containing the filter element 16, and provide a direct path from the fluid inlet 24 to the fluid outlet 26, so that the function of the entire hydraulic system to which the filter device is connected is not impaired or even interrupted. Figure 12 shows the respective receptacles for the valves 100, 102 and the closing parts 106 for the respective spring-loaded bypass valve 102 from below onto the rotary valve housing 46.

[0051] As can also be seen from Figures 11 and 12, in the area of ​​the lower connection piece 114, which opens with its free lower end 117 into the upper end area of ​​the screwed-on housing lower part 14, there is a wedge-shaped flow divider 116 which serves to reduce pressure losses during operation on both the outlet side and the inlet side of the rotary valve housing 46 and is pivoted centrally into the outlet 26 or inlet 24 in the release position.

[0052] The connection of the lower housing part 12 to the upper end cap 40 of the filter element 16 is described in more detail below, as is the structure of the upper end cap 40.

[0053] As Figures 7 and 8 in particular show, the upper end cap 40 has a circumferential circular retaining ring 118 which is widened in diameter on the outer circumference and projects axially and radially beyond a ring-side element receptacle 120 which serves to receive the upper free end face of the pleated element material 30, although this is not shown in Figures 7 and 8 for the sake of simplicity of illustration. The retaining ring 118 is integrally connected to the upper side 70 of the end cap 40 via obliquely running retaining webs 122, with two diametrically opposed retaining webs 122 being provided with crosswise webs 124 for further reinforcement.The retaining ring 118 with its webs 122, 124 is in any case an integral component of the upper end cap 40 such that ring-segment-like fluid passages 126 are present between the upper side 70 of the end cap 40 and the retaining ring 118, through which the unfiltered material can flow from the fluid inlet 24 into the fluid chamber 28 with the filter element 16 from above, in order to then flow through the element material 30 from the outside to the inside, so that a fluid flow is present from the fluid chamber 28 to the inside 32 of the filter element 16. In a cavity between the cylindrical inside of the retaining ring 118 and the cylindrical outside of the upper element cap 40, the unfiltered material flow is thus guided outside the element receptacle 120.

[0054] The retaining ring 118 preferably has at least one catch 128 on its downwardly facing end edge, but preferably two or three catches 128 (Figure 6), which extend equidistantly from one another on the underside of the retaining ring 118. As shown in particular in Figure 9, the associated pot-shaped housing lower part 14 has rectangular recesses 130 on its free upper end face, into which the respective catch 128 can engage with a precise fit from above. When the retaining ring 118 is fully placed on the upper side of the housing base 14, both a force-locking and a form-locking connection of the filter element 16 to the housing base 14 via the upper end cap 40 is created via the pairs of catches 128 with recesses 130. In this way, the filter element 16 can be driven in the same direction of rotation during both the screwing-on and unscrewing movements with the housing base 14.If the lower housing part 14 is screwed into the functional or operating position as shown in Figure 1, the retaining ring 118 with its opposite upper and lower end faces 132 and 134 comes into contact with adjacent wall parts of the upper housing part 12 or the lower housing part 14, respectively, in a position-determining manner. In this way, a secure clamping fixation of the filter element 16 via the retaining ring 118 between the upper housing part 12 and the lower housing part 14 in the operating position is achieved.

[0055] As can be seen further, particularly from Figure 8, a joint shell 136 is provided in a concentric arrangement with the central opening of the element cap 40, comprising a shell part 138 which is pivotally guided in a shell receptacle 140 in the manner of a spherical cap. The hollow cylindrical shell part 136 has, centrally on at least one retaining web 142, which is preferably connected in a ring-shaped manner to the inside of the pivotable shell part 138, an annular sealing surface 144, which forms a seal with the pivotable rotary valve housing 46 in the operating position as soon as the latter comes into contact with the upper side of the sealing ring 144 with its lower free edge 117 of the connecting piece 114. For this purpose, the sealing ring 144 preferably has a bevelled or roof-shaped sealing edge 146, which forms the seal with the free end face of the lower contact surface 117 of the connecting piece 114 of the rotary valve housing 46 (Figure 5).The circumferential sealing edge 146 can be freely pivoted via the joint shell 136, i.e. the pivotable shell part 138, which is movably arranged within the shell receptacle 140, with its connection point 145 can automatically adapt to the connection geometry of the connection piece 114 of the rotary valve housing 46. In this way, tolerance differences between the connection piece 114 and the sealing ring 144 can be compensated within the joint shell 136. Even if the connection piece 114, as shown in Figure 2, is provided with an extreme bevel at its free lower end, the sealing ring 144 can easily compensate for this difference via the joint shell 136 and create a securely sealed internal fluid guide 38 between the outlet side 26 of the filter device and the inner or filtrate side 32 of the filter element 16 via the sealing edge 146 of the sealing ring 144.Counterfeit protection can also be achieved through a suitable selection of the connection geometry on the control device 22 or on the rotary valve housing 46. This has no equivalent in the prior art.

Claims

P a t e n t a n s p r ü c h e 1. A filter device with a filter housing (10) comprising at least an upper housing part (12) and a lower housing part (14), which is designed to at least partially accommodate a filter element (16) in an exchangeable manner, and with a control device (22) for controlling fluid flows in the upper housing part (12), which in a blocking position separates a fluid-carrying connection between a fluid inlet (24) and a fluid outlet (26) and releases this connection in a release position, wherein the control device (22) can be controlled by means of an actuating device (44) on the filter element such that when the lower housing part (14) is separated from the upper housing part (12), the control device (22) moves into the blocking position, and when the lower housing part (14) is attached to the upper housing part (12), the release position is established, characterized in that the control device (22) has a rotary valve housing (46) with at least one coupling element (48, 50),which cooperates to form at least one coupling (52, 53) with corresponding coupling elements (54, 56, 58, 60) on the filter element (16) as the actuating device (44) in such a way that when the housing lower part (14) is attached or removed, at least one of the corresponding coupling elements (54, 56, 58, 60) comes into driving contact with the respective associated coupling element (48, 50) of the rotary valve housing (46) and moves the latter from the blocking position to the release position or vice versa, with subsequent release of the respective coupling (52, 53) as soon as one of the positions is assumed by the rotary valve housing (46).

2. Filter device according to claim 1, characterized in that the respective coupling (52, 53) designed in the manner of a ratchet coupling has two adjacent, opposite pairs of spring tongues as corresponding coupling elements (54, 60; 56, 58) on an end cap (40) of the filter element (16), which protrude in a resiliently yielding manner into a movement path (72) of at least one control cam as the one coupling element (48, 50) of the rotary valve housing (46).

3. Filter device according to claim 1 or 2, characterized in that the rotary valve housing (46) has two fluid passages (76, 78) and two shut-off walls (80, 82) which can be brought into alignment with the fluid inlet (24) and outlet (26) in the release or blocking position.

4. Filter device according to one of the preceding claims, characterized in that the rotary valve housing (46) has a further control cam (84) which is guided in a slotted guide (88) in the upper housing part (12) and limits the movement of the rotary valve housing (46) between the blocking and the release position.

5. Filter device according to one of the preceding claims, characterized in that between the filter element (16) and the lower housing part (14) there is a carrier (128) which, in the case of a relative movement between the stationary upper housing part (12) and the lower housing part (14) which is movable relative thereto, carries along the filter element (16) accommodated in the lower housing part (14) in the same direction.

6. Filter device according to one of the preceding claims, characterized in that the rotary valve housing (46) on the side of the fluid outlet in the upper housing part (12), has a receptacle (90) for an annular seal which, in the release position, seals the fluid transition between the fluid outlet (26) and an inner fluid guide (38) in the rotary valve housing (46).

7. Filter device according to one of the preceding claims, characterized in that the inner fluid guide (38) passes through the rotary valve housing (46) at a right angle and has, at its free end facing away from the fluid outlet (26), a connection bevel for the fluid-carrying connection of the filter element (16) on its inner side (32).

8. Filter device according to one of the preceding claims, characterized in that the rotary valve housing (46) has a further internal fluid guide (39) which, in the release position, establishes a fluid-carrying connection between the fluid inlet (24) and a fluid space (28) which is formed by the filter element (16) and the housing lower part (14) in an operating position.

9. Filter device according to one of the preceding claims, characterized in that the rotary slide housing (46) has at least one safety valve (100) which, when flowing through the rotary slide housing (46) in its blocking position, opens from the fluid inlet (24) to the fluid outlet (26) and releases the respective fluid path, bypassing the fluid space (28) in the lower housing part (14), and that preferably a contamination indicator (110) is connected in the respective fluid path.

10. Filter device according to one of the preceding claims, characterized in that at least one bypass valve (102) is accommodated in the rotary valve housing (46), which in the release position, from a predefined degree of contamination of the filter element (16), bypassing the fluid path between fluid inlet (24) and outlet (26) during operation. 1 1. Filter element, in particular intended for use in a filter device according to one of the preceding claims, with an element material (30) which has an end cap (40) on at least one free end face, characterized in that this end cap (40) has individual coupling elements (54, 56, 80, 60) which project outwards as part of at least one coupling (52, 53).

12. Filter element according to claim 11, characterized in that the coupling elements (54, 56, 58, 60) of the end cap (40) are formed from at least one pair, preferably two pairs, of mutually adjacent, opposite spring tongues, each of which protrudes inwardly by a predeterminable distance along a movement path (72).

13. Filter element according to claim 11 or 12, characterized in that the movement path (72) is limited by shell-like guide surfaces (74) as a component of the respective coupling (52, 53), which protrude beyond the assignable end cap (40) and are limited at the end by a respective spring tongue.

14. Filter element according to one of claims 1 1 to 13, characterized in that the shell-like guide surfaces (74) are surrounded outwards by a retaining ring (118) which, viewed in the axial direction, projects at least partially beyond the guide surfaces (74) and which is firmly connected, preferably in one piece, to the assignable end cap (40) via webs (122, 124).

15. Filter element according to one of claims 11 to 14, characterized in that the retaining ring (118) projects beyond the edge of the end cap (40) and has at least one projecting catch (128) in the direction thereof.

16. Filter element according to one of claims 11 to 15, characterized in that a joint shell (136) is pivotally inserted into a central opening of the end cap (40), which joint shell has a connection point (145) that can be inclined in predeterminable directions to form a fluid guide (38) to the inner side (32) of the filter element (16). 1 7. Filter element according to one of claims 11 to 16, characterized in that end parts of the element material (30) comprise the joint shell (136) in an element receptacle (120) of the end cap (40).

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