Filter Device

Abstract

To provide a filter apparatus having a filter housing (14) comprising a housing pot (12), which accommodates an exchangeable filter element (16) and is closed by a removable cover part (32).SOLUTION: There is provided a filter apparatus in which an element material (20) of the filter element (16) separating an un-filtrate chamber (22) from a filtrate chamber (18, 43), and which includes a measurand sensing device (108) for sensing pressure values from at least one of the chambers (18, 22, 43), and further in which, the measurand sensing device (108) is arranged on a cover inner side (45) of a cover part (32) and, at least partially guided in the cover part (32), protrudes into a filter housing (14), and at least parts of a measurand evaluation device (78) connected to the measurand sensing device (108) are arranged facing an environment on an opposite cover outer side (42).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The invention relates to a filter device having a filter housing (14) consisting of a housing pot (12) which accommodates a replaceable filter element (16) and which is closed by a removable lid member (32), the element member of the filter element separating an unfiltrate chamber from a filtrate chamber, and further comprising a measured value detection device for detecting the pressure value of at least one of the chambers. [Background technology]

[0002] Filter devices of this type have been disclosed in the past in various embodiments with replaceable filter elements complying with different specifications. In these filter devices, the filter elements are used for fluid servicing, in particular in hydraulic systems. To ensure the operational reliability of the plant, which essentially depends on the perfect performance of the filter device, the dirt retention capacity of the filter element is often monitored. As stated in DE 10 200 63 33 A1, which discloses a filter device of the type mentioned at the outset, in known filter devices the dirt retention capacity is monitored by measuring the pressure difference between the unfiltrate side and the filtrate side, in order to avoid the risk of overloading the filter medium, which would lead to operational abnormalities and even damage, which would lead to considerable economic losses in expensive systems.

[0003] In the above-mentioned known solutions, designed as so-called in-tank filter devices, the filter housing has a filter head with a fixing flange on the outer periphery, by means of which the filter head can be attached to the edge of the tank opening in such a way that a further housing part in the form of an outlet pipe, which is continuous with the lower end of the filter head, extends into the interior of the tank. The filter head has a connection area for a sensor of a soiling indicator, which protrudes radially to the fixing flange. The sensor with a measuring housing in the form of an elongated cartridge extends radially outwards from the connection area relative to the longitudinal axis of the device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] German Patent Application Publication No. 102015003604(A1) Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the invention is to provide a filter device of the type mentioned at the beginning, which is simple in construction, can be produced inexpensively and allows for determination of the degree of contamination in a particularly advantageous manner. [Means for solving the problem]

[0006] According to the invention, this problem is solved by a filter device having the features of claim 1 in its entirety.

[0007] According to the characterizing feature of claim 1, an essential feature of the invention is that the measurement value detection device is arranged on the inside of the lid of the cover element, in which it is guided at least partially into the filter housing, and at least part of the measurement value evaluation device connected to the measurement value detection device is arranged on the opposite outside of the lid element facing the surrounding environment.

[0008] In known solutions, in which the measuring housing extends laterally away from the filter head along the upper side of the tank wall, the accessibility thereto is relatively limited. A particular advantage is that the arrangement of the measurement value detection device on the inside of the lid and at least a part of the measurement value evaluation device on the outside of the lid opens up the possibility of constructing the filter device as an in-tank filter device in a particularly inexpensive and simple manner. Because the measurement value detection device projects from the lid element into the interior of the filter housing, the filter device can be constructed as an in-tank filter with pressure value detection without a filter head, the lid element itself forming both the fastening flange on the tank wall and the receptacle for the relevant end of the housing pot which is a constituent part of the filter housing. In this way, the filter device with pressure value detection can be produced in a particularly simple and inexpensive manner.

[0009] In an advantageous embodiment, the measured value detection device has a sensor flow path that is at least partially surrounded by a sensor tube that runs coaxially to the longitudinal axis of the filter element on the inside of the lid and fluidically connects one of the chambers of the filter element with a receiving chamber that is part of the measured value evaluation device and is located on the outside of the lid, so that the measured value detection device and the measured value evaluation device can be connected to each other directly and thus over the shortest possible distances.

[0010] In another advantageous embodiment, the receiving chamber has its longitudinal axis extending transversely to the longitudinal axis of the filter element on the outside of the lid and serves to receive a pressure sensor which is part of the measurement value evaluation device or a connector of the pressure sensor which is outside the receiving chamber, respectively, so that the pressure sensor or the connector can be mounted on the lid in a space-saving manner, at least in the axial direction of the lid. Furthermore, any orientation of the receiving chamber can be specified by rotating the filter device before installation at the respective place of use, so that the pressure sensor or the connector can be easily installed and removed at the respective place of use.

[0011] In another advantageous embodiment, the sensor line passes through a bypass valve which in the closed state of an element part of the filter element connects the unfiltrate side with the filtrate side and whose valve spring extends between the inside of the lid and an outlet part which in the open state closes the front opening of the filter element, so that the fluid pressure of the unfiltrate present in the bypass valve, in particular in the valve closing part of the bypass valve, can be transmitted simply to the measured value evaluation device.

[0012] In another advantageous embodiment, the part of the measurement value evaluation device that is inserted in the receiving chamber is configured as a screw-on cartridge, so that the part of the measurement value evaluation device configured as a screw-on cartridge can be easily and quickly attached to and detached from the lid.

[0013] In another advantageous embodiment, the receiving chamber has a flow path section parallel to its longitudinal axis, into which the sensor flow path opens at one free end, the flow path section forming a permanent connection with an evaluation flow path leading to a pressure sensor. Due to the alignment of the flow path section parallel to the longitudinal axis of the receiving chamber, the nonfiltrate pressure read by the measurement value detection device, in particular by the sensor flow path of the measurement value detection device, can be throttled on the fluid path leading to the measurement value evaluation device.

[0014] In another advantageous embodiment, a further sensor channel is guided in the cover, which leads in fluid communication to one of the two chambers outside the filter element and can be closed if necessary, so that the pressure on the filtrate side of the filter element can be transmitted to a differential pressure sensor to measure the differential pressure.

[0015] In another advantageous embodiment, the further sensor channel opens at its cover end into a receiving chamber in the cover, into which the front end of the pressure sensor engages, so that the differential pressure sensor can be directly subjected to the pressure on the filtrate side at its front end.

[0016] In another advantageous embodiment, the pressure sensor is a dynamic or differential pressure sensor. In a differential pressure measurement, the unfiltrate pressure acts on the sensor via a flow channel section aligned parallel to the longitudinal axis of the receiving chamber and the filtrate pressure acts on the front end of the sensor via a further sensor flow channel, while the dynamic pressure sensor detects pressure values ​​exclusively from the sensor flow channel passing through the bypass valve, whereas the differential pressure sensor detects pressure values ​​from both sensor flow channels, the further sensor flow channel of which is permanently connected in fluid communication with the filtrate side. In the case of a dynamic pressure measurement, the further sensor flow channel can be closed by a front face formed as a plug of the screw-on cartridge of the sensor or connector.

[0017] The present invention will be described in detail below based on the embodiments shown in the drawings. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of one embodiment of a filter device according to the present invention. [Diagram 2] FIG. 2 shows a perspective view of only the upper end region of a first embodiment of a filter device according to the invention, cut along a central vertical plane and excised. [Diagram 3] FIG. 3 shows a perspective view of a second embodiment of a filter device according to the invention, cut and cut corresponding to FIG. [Figure 4] FIG. 4 shows a perspective view of a third embodiment of a filter device according to the invention, cut and removed corresponding to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The invention will be explained by way of example of a so-called in-tank filter arrangement with reference to the attached drawings. For installation in a fluid container or tank, not shown in the figures, such an arrangement has a fixing flange and can be attached to a wall opening in the upper wall of said tank, such that the outlet pipe or housing pot runs vertically into the interior of the tank. The structure and function of such an in-tank filter arrangement is described in DE 10 2015 003 604 A1, which is known from the prior art.

[0020] In the figures 1 to 4, the in-tank filter arrangement 10 is shown, as is customary, with the housing pot 12 forming part of a filter housing 14 which accommodates a replaceable filter element 16 and in so doing surrounds the outer periphery of the filter element 16 and forms an intermediate chamber 18. In the figures 2 to 4, only the upper end part of the filter element is visible in the drawings. The hollow cylindrical filter element 20 of the filter element 16, which surrounds a filter cavity 22, extends as is customary between two end caps 24, of which only the upper end cap 24 is visible in the figures 2 to 4. During operation of the in-tank filter, unfiltrated liquid is fed through the lower end cap, not shown, into the inner filter cavity 22, so that the filter cavity 22 forms the unfiltrate side 26 and the intermediate chamber 18, which is on the outside of the filter element, forms the filtrate side 28. From here, the filtrate passes through a window opening 30 in the housing pot 12 into the interior of the tank.

[0021] The filter housing 14 is closed at the top by a lid member 32 which, in the variant shown in FIG.

[0022] In the exemplary embodiment of Figures 2 to 4, the lid member 32 and the fixing flange 36 are integral, and the fixing flange 36 is adjacent to its side facing the housing pot 12, in particular the face 38, with a sealing ring 40 that surrounds the lid member 32, so that the fixing flange 36 can be sealed against the tank wall when the lid member 32 is screwed into an opening in the tank wall, not shown.

[0023] The lid element 32, which together with the housing pot 12 forms the entire filter housing 14, has in particular a slightly convexly curved outer side 42 and together defines an inner chamber 43, the trough-shaped ceiling 44 of which has a convex curvature corresponding to the outer curvature on the lid inner side 45. In FIGS. 1 to 4, the housing pot 12 is guided with its upper end part inside a cylindrical wall 46 of the lid element 32, which also together defines the inner chamber 43. Alternatively, the housing pot 12 can be fixed inside the wall 46, for example glued to the wall 46. During the filtering operation, the inner chamber 43 of the lid element 32 next to the intermediate chamber 18 then forms the filtrate side 28. The wall 46 is provided on its outer side with a thread 48 for screwing the lid element 32 into an opening in the tank wall.

[0024] The upper end cap 24 of the filter element 16 forms a frame for the upper end of the filter element 20 in the usual way and for the upper end of the support tube 50, which rests against the outside of the filter element 20 in the form of a grid-like support structure, and has a central opening 52 on its planar upper side. On the lower side, the opening 52 is surrounded by a connecting element 54 which projects into the inner filter cavity 22 of the filter element 16. The central opening 52 forms with its edge a sealing seat for a closing body 56 of a bypass valve 58, which closes the through-passage formed in the connecting element 54 between the inner filter cavity 22 and the interior space 43 bounded by the lid element 32. On its upper side, the end cap 24 has a fastening device 60 which cooperates with a holding device 62 of the lid element 32 which extends through the interior space 43 of the lid element 32 in the direction away from the lid element 32 in order to position and hold the filter element 16 in its installed position. The retaining device 60 has three retaining parts 64 projecting upward from the upper side of the end cap 24, which are arranged near the upper periphery and offset from one another by 120°, two of which are visible in FIGS. 2 to 4. The retaining parts 64 each have the form of a cylindrical section coaxial with the longitudinal axis of the device and, as can be seen from the retaining part 64 located on the left side in FIGS. 2 to 4, are bent at a right angle and merge in a radially stepped surface into a radially outwardly offset protruding end 68. The assigned retaining device 62, which extends from the ceiling 44 of the lid part 32 into the inner chamber 44, has for each retaining part 64 a retaining part 72 connected to the ceiling 44 via a foot 70, which has a coaxial internal guide link into which the protruding end 68 of the retaining part 64 can enter by a relative rotational movement between the filter element 16 and the lid part 32. In the inserted position, a sort of bayonet lock is formed, with the stepped surface 66 axially securing the filter element 16 together with the wall surface of the guide link 74 by form-fitting.

[0025] The embodiment of Fig. 2 has a centrally arranged attachment 76 on the upper side of the lid part 32, in which, as part of a measured value evaluation device 78, a receiving chamber 80 for a pressure sensor 82 or a connection element 84 (Fig. 4) for a pressure sensor 82 which is outside the receiving chamber 80 and which can ascertain the degree of contamination of the filter element 16. The sensor 82 shown in Fig. 2 is a differential pressure sensor 86 with a sensor housing 88 in the form of a screw-on cartridge. The respective pressure sensor 82 and possibly also the connection element 84 are part of the measured value evaluation device 78.

[0026] The receiving chamber 80 is formed in the form of a flow passage, the longitudinal axis of which runs radially perpendicular to the longitudinal axis of the device and is radially offset with respect to the longitudinal axis of the cover element 32 or the filter element 16, and has a closed end 90, through which the sensor housing 88 or the connecting element 84 can be inserted into the receiving chamber 80. Near the closed end 90 of the flow passage, the receiving chamber 80 has an internal thread 94, into which the sensor housing 88 or the connecting element 84 can be screwed with its external thread 96, a sealing ring 98 sealing the sensor housing 88 or the connecting element 84 to the receiving chamber 80. The internal thread 94 of the receiving chamber 80 is followed by a connecting flow passage section 100, in which the pressure value of the nonfiltrate pressure is transmitted to the sensor 32. To form the corresponding fluid connection by the connecting flow passage section 100, the receiving chamber 80 has a wall recess which extends along the inner wall of the receiving chamber 80 and forms a transverse flow passage 102.

[0027] To transmit the pressure value to the connecting flow-path section 100, the sensor flow path 104 opens into the transverse flow path 102, starts from a centrally located hole 106 in the cover element 32 as part of a measured value detection device 108, runs coaxially to the longitudinal axis of the device, passes through an outlet member 56 of a bypass valve 58 and is thus directly connected to the hollow space 22 of the filter element 16 which guides the nonfiltrate pressure on the inlet side. Starting from the hole 106, the sensor flow path 104 is formed in the form of a guide sleeve by a sensor tube 114 which is also part of the measured value detection device 108, on which the outlet member 56 of the bypass valve 58 is guided axially movably. The outlet member 56 in the form of a dish-shaped closing body is biased by a valve spring in the form of a compression spring 116 which surrounds the sensor tube 114 into a closed position in which it seals with the edge of the opening 52 in the end cap 24, so that in the unblocked state of the filter element 16 the front-side opening is closed. A compression spring 116, specifically a compression coil spring, is clamped between the outlet member 56 and the ceiling 44 of the lid member 32. When the element member 20 of the filter element 16 is in a closed state, the outlet member 56 is lifted from the valve seat, i.e., the edge of the opening 52 in the upper end cap 24, against the spring force of the compression spring 116 by the fluid pressure present in the nonfiltrate side 26, thereby connecting the bypass valve 58 to the nonfiltrate side 26 and the filtrate side 28.

[0028] In the embodiment of Fig. 2 with differential pressure measurement, the sensor housing 88 has an inclined evaluation channel 118 in a position aligned with the connecting channel section 100, which makes a fluid connection from the sensor channel 104 to a pressure chamber 120 in the sensor housing 88. The pressure chamber 120 is in a measuring cylinder 122 in the sensor housing 88. The nonfiltrate pressure, which is transmitted to the pressure chamber 120 in the measuring cylinder 122 via the evaluation channel 118, loads one piston face 124 of a measuring piston 126. The measuring piston 126 is displaceable in the measuring cylinder 122 and is biased by a compression spring 128 against the displacement movement caused by the nonfiltrate pressure. For the differential pressure measurement, another piston face 130 of the measuring piston 126, which faces away from the pressure chamber 120, is loaded by the filtrate pressure. For this purpose, the end of the measuring cylinder 122 facing away from the pressure chamber 120 is fluidly connected via a throttle bore 132 with the closed end 90 of the receiving chamber 80, in which the pressure sensor 82 engages with its front end 146. Since the closed end 90 of the receiving chamber 80 is offset from the center in the cover 32, the fluid connection between the closed end 90 of the receiving chamber 80 and the filtrate side 28 in the inner chamber 43 of the cover 32 can be made by a separate sensor channel 134. The sensor channel 134 runs as part of the measured value detection device 108 in the form of a vertical bore 136, starting from the receiving chamber 80, through the upper side of the cover 32, through the inner chamber 43 into the intermediate chamber 18 and there opens into the filtrate side 28 outside the bypass valve 58. A sensor board 138 is provided in the filter housing 14 for generating a signal based on the movement of the measuring piston 126 by means of differential pressure, by means of a conventional non-contact measuring method, for example a measuring method based on the Hall effect.

[0029] The embodiment of FIG. 3 corresponds completely in content to the embodiment of FIG. 2, except that instead of the differential pressure sensor 86 provided for the differential pressure measurement, a dynamic pressure sensor 140 is provided in the receiving chamber 80, which is on the lid part 32 and is bounded by the attachment 76 together. The sensor housing 88 of the dynamic pressure sensor 140, which is configured as a screw-in cartridge, does not have an internal flow passage as a measuring cylinder for a measuring piston, but only a pressure transducer 142 for dynamic pressure measurement. The pressure transducer 142 is therefore directly loaded with the unfiltered pressure transmitted by the sensor flow passage 104 via the further evaluation flow passage 144 and the connecting flow passage section 100 in the receiving chamber 80. Since the filtrate pressure is not taken into account in the dynamic pressure measurement and therefore the further sensor flow passage 134 does not function, the front end 146 of the sensor housing 88 in the example of FIG. 3 is formed as a plug and closes the connection with the further sensor flow passage 134 together with the sealing ring 98.

[0030] The embodiment of Fig. 4 corresponds substantially to the embodiment of Fig. 3, except that the connecting member 84 designed as a screw-in cartridge is received, and in particular screwed, into the receiving chamber 80. The nonfiltrate pressure present in the connecting member 84, which is read via the sensor flow channel 104 and the connecting flow channel section 100 in the filter cavity 22, is transmitted by the connecting member 84 through a fluid conduit 150 to a dynamic pressure sensor 140 arranged remote from the receiving chamber 80 and / or the connecting member 84, which corresponds in its way of functioning to the dynamic pressure sensor 140 of Fig. 3. For this purpose, at least two flow passage sections 152, 154 are provided in the connecting member 84, aligned vertically and fluidly connected to each other, each of which is introduced into the connecting member 84 through a hole, one of which, extending through the connecting member 84 in the direction of the longitudinal axis of the filter element 16, flows into the connecting flow passage section 100 of the receiving chamber 80, and the other of which, extending through the connecting member 84 in the direction of the longitudinal axis of the receiving chamber 80, opens in fluid communication into the fluid tube 150. Each of the flow passage sections 152, 154 can have an enlarged inner diameter in the direction of the end exiting the connecting member 84, preferably in the form of a step. The present invention has the following configurations. [Configuration 1] A filter device having a filter housing (14) consisting of a housing pot (12), The housing pot contains a replaceable filter element (16) and is closed by a removable lid member (32); The filter device comprises an element member (20) of the filter element (16) separating an unfiltrate chamber (22) from a filtrate chamber (18, 43), and a measurement value detection device (108) for detecting a pressure value of at least one of the chambers (18, 22, 43), the measured value detection device (108) is arranged on the lid inner side (45) of the lid member (32) and is guided at least partially within the lid member (32) and projects into the filter housing (14); A filter device, characterized in that at least a part of a measurement value evaluation device (78) connected to the measurement value detection device (108) is arranged on an outer side (42) of the lid opposite to the ambient environment. [Configuration 2] 2. The filter device according to claim 1, wherein the measurement value detection device (108) has a sensor flow path (104) at least partially surrounded by a sensor tube (114) which extends coaxially to the longitudinal axis of the filter element (16) on the inside of the lid (45) and fluidically connects one of the chambers (22) of the filter element (16) to a receiving chamber (80) on the outside of the lid (42), the receiving chamber (80) being part of the measurement value evaluation device (78). [Configuration 3] 3. The filter device according to claim 1 or 2, characterized in that the receiving chamber (80) has a longitudinal axis which extends transversely to the longitudinal axis of the filter element (16) on the lid outer side (42) and serves to receive a pressure sensor (82) or a connecting member (84) of the pressure sensor (82) located outside the receiving chamber (80) as part of a measured value evaluation device (78), respectively. [Configuration 4] 4. The filter device according to any one of configurations 1 to 3, wherein the sensor tube (114) passes through a bypass valve (58) that connects a nonfiltrate side (26) to a filtrate side (28) when the element member (20) of the filter element (16) is blocked, and a valve spring (116) of the bypass valve (58) extends between an inner lid side (45) and an outlet member (56) that closes a front opening (52) of the filter element (16) in an unblocked state. [Configuration 5] 5. The filter device according to any one of configurations 1 to 4, characterized in that in the receiving chamber (80) the respectively inserted parts of the measured value evaluation device (78) are configured as screw-on cartridges. [Configuration 6] 6. A filter device according to any one of configurations 1 to 5, characterized in that the receiving chamber (80) has a flow path section (100) parallel to its longitudinal axis, into which the sensor flow path (104) opens at one free end, and which flow path section (100) forms a permanent connection with the evaluation flow path (118, 144) of the pressure sensor (82). [Configuration 7] 7. The filter device according to any one of configurations 1 to 6, characterized in that a separate sensor channel (134) is guided within the cover element (32), which sensor channel (134) is fluidically connected to one of the two chambers (18, 43) outside the filter element (16) and can be closed as required. [Configuration 8] The filter device according to any one of configurations 1 to 7, wherein a cover side end of the another sensor flow path (134) opens into a receiving chamber (43) in the cover member (32), and a front end (146) of the pressure sensor (82) engages with the receiving chamber (43). [Configuration 9] 9. The filter device according to any one of configurations 1 to 8, wherein the pressure sensor (82) is a dynamic pressure sensor (140) or a differential pressure sensor (86). [Configuration 10] 10. The filter device according to any one of configurations 1 to 9, characterized in that the dynamic pressure sensor (140) detects pressure values ​​solely from the sensor flow path (104) on the nonfiltrate side (26), and the differential pressure sensor (86) detects pressure values ​​from the two sensor flow paths (104, 134), the other sensor flow path (134) being permanently connected in fluid communication with the filtrate side (28).

Claims

1. A filter device having a filter housing (14) consisting of a housing pot (12), The housing pot contains a replaceable filter element (16) and is closed by a removable lid member (32); A filter device comprising an element member (20) of the filter element (16) separating an unfiltrate chamber (22) from a filtrate chamber (18, 43), the filter device having a measurement value detection device (108) for detecting a pressure value of at least one of the unfiltrate chamber (22) and the filtrate chamber (18, 43), the measurement value detection device (108) is arranged on the lid inner side (45) of the lid member (32) and is guided at least partially within the lid member (32) and projects into the filter housing (14); At least a part of a measurement value evaluation device (78) connected to the measurement value detection device (108) is arranged on the outer side (42) of the lid opposite to the ambient environment, the filter device is an in-tank filter device; Nonfiltrate is fed to said nonfiltrate chamber (22) through a lower end cap; The nonfiltrate chamber (22) defines a nonfiltrate side (26), The filtrate chamber (18, 43) on the outside of the element member (20) forms a filtrate side (28); The filtrate enters the interior of the tank from the filtrate side (28) through a window opening (30) of the housing pot (12); the measured value detection device (108) has a sensor flow path (104) at least partially surrounded by a sensor tube (114) that extends coaxially with respect to a longitudinal axis of the filter element (16) on the inside of the lid (45) and fluidically connects one of the non-filtrate chambers (22) of the filter element (16) to a receiving chamber (80) on the outside of the lid (42), the receiving chamber (80) being part of the measured value evaluation device (78); a separate sensor channel (134) is guided in the cover member (32), the sensor channel (134) being in fluid communication with one of the two filtrate chambers (18, 43) outside the filter element (16) and being closable as required; A filter device comprising:

2. 2. The filter device according to claim 1, characterized in that the receiving chamber (80) has a longitudinal axis which extends transversely to the longitudinal axis of the filter element (16) on the lid outer side (42) and serves to receive a pressure sensor (82) or a connecting element (84) of the pressure sensor (82) which is outside the receiving chamber (80) as part of the measured value evaluation device (78), respectively.

3. 2. The filter device according to claim 1, characterized in that the sensor tube (114) passes through a bypass valve (58) which connects the unfiltrate side (26) to the filtrate side (28) when the element member (20) of the filter element (16) is blocked, and a valve spring (116) of the bypass valve (58) extends between an inner side of the lid (45) and an outlet member (56) which closes a front opening (52) of the filter element (16) in an unblocked state.

4. 2. The filter device according to claim 1, wherein the measurement value evaluation device (78) used in the receiving chamber (80) is configured as a screw-on cartridge.

5. 2. The filter device according to claim 1, characterized in that the receiving chamber (80) has a flow path section (100) parallel to its longitudinal axis, into which the sensor flow path (104) opens at one free end, and which forms a permanent connection with an evaluation flow path (118, 144) of a pressure sensor (82).

6. The filter device according to claim 1, characterized in that the cover side end of the other sensor flow path (134) opens into the filtrate chamber (43) in the cover member (32), and a front end (146) of the pressure sensor (82) engages with the filtrate chamber (43).

7. 7. The filter device of claim 6, wherein the pressure sensor (82) is a dynamic pressure sensor (140) or a differential pressure sensor (86).

8. 8. The filter device of claim 7, wherein the dynamic pressure sensor (140) detects pressure values ​​exclusively from a sensor flow path (104) on the nonfiltrate side (26), and the differential pressure sensor (86) detects pressure values ​​from two sensor flow paths (104, 134), the other sensor flow path (134) being permanently connected in fluid communication with the filtrate side (28).

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