Filter element

Abstract

The invention relates to a filter element comprising an element material (10) which delimits an interior (26) and which extends between two closure parts (12, 14), one closure part (12) thereof having a spherical bearing (24) and a fluid-conducting connection part (18) which leads in the direction of the interior (26). The invention is characterized in that the other closure part (14) has at least one control surface (20), each of which holds the element material (10) in an installation position relative to the connection part (18) in a non-actuated state and each of which brings the element material (10) into a functional position, which is collision-free for the filter element, relative to the connection part (18) by means of the spherical bearing (24) in an actuated state.

Description

[0001] Filterelement

[0002] The invention relates to a filter element with an element material that delimits an interior space and extends between two end parts, one of which has a spherical bearing and a fluid-conducting connection part that opens out towards the interior space. DE 10 2018 009 187 A1 discloses a filter device with a filter housing and a filter element received therein, the element material of which extends between two end caps as the two end parts, of which at least one end cap is mounted on an element holder, wherein the filter element is articulated to the element holder via its one end cap by means of a bearing providing more than one degree of freedom. The known solution is designed as a so-called in-tank solution with an inflow opening for unfiltered material, which is integrated in a filter head that fastens the filter device to a tank wall.The element is filtered from the outside inward to remove particles from the fluid flow, and the filtrate flow enters the tank interior via a central opening at the bottom of the shell parts associated with the spherical bearing. Extremely tight tolerances must be maintained during the manufacture of filter housings and filter housing components to ensure that the axes of the respective element receptacles of the end caps are precisely aligned with the axes of the housing-side and / or cover-side retaining elements, such as nozzles. Manufacturing tolerances during housing production, particularly in multi-part housing designs with several adjoining housing components, can lead to misalignment, which can cause distortion in the filter element and result in malfunctions or even damage.Filter devices that accommodate large filter elements in terms of their overall length are particularly affected by this problem, since even the smallest angular errors and position deviations result in a large offset on the opposite holding element.

[0003] This problem has been addressed by the technical teaching according to DE 10 2018 009 187 A1. The fact that the filter element is pivotally mounted on the element holder via its one end cap by means of a bearing providing more than one degree of freedom provides an opportunity to compensate for possible misalignment errors. This makes it possible to reduce the tight tolerance limits that must be observed during production. This means that filter devices can be manufactured reliably and at low production costs, even with long filter elements or with assembled filter housings. In the known solution, the filter element, which is pivotably mounted on the base, must be aligned by hand with axial precision, preferably along the vertical, into an operating or functional position so that a cover-like connection piece of the filter head with an outer sealing ring can engage flush with the central opening of the upper end cap.

[0004] Based on this prior art, the invention seeks to further improve the known solution. This object is achieved by a filter element having the features of patent claim 1 in its entirety.

[0005] Due to the fact that, according to the characterizing part of patent claim 1, the other end part has at least one control surface which, when not actuated, holds the element material in an installed position relative to the connecting part as a pivot bearing and which, when actuated, brings the element material relative to the connecting part into an operating or functional position by means of the spherical bearing which is collision-free for the filter element, it is ensured that the filter element can be aligned into one of its functional positions almost automatically via the respective control surface on the filter element during installation.When installing the filter element in a hollow cylindrical filter housing of an unspecified type, the filter element can inevitably assume a corresponding inclined position due to the known spherical bearing on its base part, which, unless corrected by hand in the direction of the vertical functional position, makes it impossible to screw on an associated housing cover or to make any other fluid-tight connection between a cover part and other tank or housing parts, because the filter element in its inclined installation position makes this connection process more difficult or even completely impossible.

[0006] With the solution according to the invention, however, when establishing the fluid-tight connection between the cover part and the rest of the housing or tank, the filter element is automatically aligned by means of the respective control surface in the direction of a vertical alignment axis for the operation of the device, so that the filter element always reaches its filtering functional position without having to manually align the filter element via its base-side bearing point, which is not easy to accomplish and can frequently be forgotten. In particular, the filter element according to the invention makes its installation significantly easier and faster.In a preferred embodiment of the filter element according to the invention, it is provided that the respective control surface is part of a control body which projects axially into the surroundings by a predeterminable projection beyond the element material and which has a predeterminable inclination, the angle of which is selected such that, upon actuation of the control body, the element material self-lockingly assumes its predetermined, collision-free position by means of the spherical bearing. In this way, an unobstructed alignment of the filter element into its quasi-vertical functional position is guaranteed in every case, and the inclination of the respective control surface can be selected such that, within a wide range for the most diverse embodiments of a cover part as part of an overall housing of an unspecified type, the alignment process for the filter element as a whole is effectively triggered.It has been shown that the control body has a control cone towards its free end face, the at least one control surface of which encloses an acute angle of preferably less than 45°, particularly preferably of approximately 30°, with a longitudinal axis of the element material.

[0007] In a further preferred embodiment of the filter element according to the invention, the control body is an integral component of an end cap which has an element receptacle for receiving the element material on the front side, and the control body, starting from its inclined control surface, transitions into a cylindrical shoulder in the direction of the adjacent upper side of the end cap. This allows the end cap to be manufactured together with the control body in a particularly cost-effective manner, for example using an injection molding process. Furthermore, the shoulder creates a type of free surface which enables parts of the cover to slide off the respective control surface without hindrance, provided the cover is connected to other tank or housing parts, for example by screwing.In a further preferred embodiment of the filter element according to the invention, the control body is centrally penetrated by an opening for the flow of fluid, which can preferably be covered by a valve closing element of a bypass valve, which is accommodated inside the element material and connected, preferably in a latching manner, to the adjacent end cap. In this way, when the element material is clogged with particle contamination (also known in technical terms as blocking), the fluid flow can be guided around the filter mat in a type of bypass or short-circuit operation, so that a hydraulic circuit connected to the filter element does not have to be immediately shut down for an element change.

[0008] In terms of fluid flow, it has proven advantageous for the control body to be radially penetrated by fluid passages that open into the environment on one side in the form of a fluid chamber and toward the valve closure element on the other, opposite side. The respective control surfaces of the control body, which define the fluid passages, can also contribute to a turbulence-free fluid flow through the filter element, especially when aligned parallel.

[0009] In a further preferred embodiment of the filter element according to the invention, the control body is arranged coaxially to the longitudinal axis of the element material and protrudes axially beyond the associated end cap by a predeterminable length, which is smaller, preferably by half, particularly preferably by one-third, than the diameter of the control body at its base-side transition point to its end cap. This results in a compact design of the alignment solution according to the invention in the area of ​​the associated upper end cap, so that such filter elements can be easily used even in confined installation conditions.In a further preferred embodiment of the filter element according to the invention, at least the upper side of the end cap and the control body itself are designed as a ribbed structure with a plurality of individual ribs, and the inclined individual ribs of the control body form the respective control surface. Due to the ribbed structure, a rigid construction is achieved for the associated end cap, which thus provides secure support for the adjacent element material integrated into the end cap.

[0010] In a further preferred embodiment of the filter element according to the invention, the connecting part of one end piece has a threaded section and a contact surface running transversely thereto, and the further end cap of the element material has a further contact surface, which, in the functional position, pivots by means of the spherical bearing and partially rests on one contact surface. This results in a type of counterfeit protection, which is intended to ensure that the manufacturer's original filter elements cannot be casually exchanged for cheap counterfeit products that are generally of inferior quality.

[0011] It is preferably provided that the spherical bearing of the filter element has a fixable bearing shell on the connecting part, relative to which a shell part of the end cap with the element material is guided so as to be movable, in particular pivotable.

[0012] The filter element according to the invention is explained in more detail below using an exemplary embodiment according to the drawings. In a schematic representation and not to scale, the

[0013] Figure 1 shows an external view of the filter element as a tradeable and replaceable unit;

[0014] Figure 2 shows a longitudinal section through half of the filter element according to Figure 1; Figures 3 and 4 show a filter element, in particular according to Figures 1 and 2, in the deflected and the returned state; and

[0015] Figure 5 shows the base part of the filter element according to Figures 1 and 2.

[0016] Figure 1 shows the complete filter element in an external view. The filter element comprises an element material 10, which serves in particular to filter out particulate contamination from a fluid stream. The element material 10 can be pleated as usual, although the corresponding filter folds have been omitted from the figures for simplicity of illustration. Furthermore, the element material 10 extends between two end parts 12, 14, which are designed as end caps 13, 15. Figure 1 shows the filter element as a whole with a vertical installation direction that corresponds to the usual desired operating or functional position of the filter element, which in turn corresponds to the filtration position.

[0017] As Figure 1 further shows, as viewed in the direction of Figure 1, the filter element is provided on its underside with an external thread 16 which is a component of a fluid-conducting connecting part 18 in the form of a hollow connecting piece. The upper end part 12 has individual control surfaces 20 which are grouped in a concentric arrangement around the longitudinal axis 22 of the filter element. Figure 2 shows, in a semi-longitudinal section through the filter element according to Figure 1, that the lower end part 14 has a spherical bearing 24 as a whole and the fluid-conducting connecting part 18 in the form of the connecting piece with the external thread 16. The hollow cylindrical element material 10 comprises an interior space 26 and is supported on a fluid-permeable support tube 28, wherein for the sake of simplicity the individual fluid passages, for example in the form of a perforation, are not shown.The support tube 28 is formed in particular from a strip material, preferably from sheet metal, which is wound into a tube, wherein the individual web sections are connected to one another in a fluid-tight manner via a spiral-shaped flanged seam 30.

[0018] As further shown in Figures 1 and 2, the respective control surface 20 is a component of a control body 32, which projects axially into the surrounding area at the end by a predeterminable projection beyond the element material 10 and which has a predeterminable inclination, the angle of inclination x of which is selected such that, upon actuation of the respective control body 20, the element material 10 self-lockingly assumes its predetermined collision-free operating or functional position by means of the spherical bearing 24, as can be seen in more detail in the illustrations according to Figures 3 and 4 and will be explained in more detail below. The indicated angle of inclination x also corresponds to the inclination of the respective control surface 20 relative to the longitudinal orientation of the element in the form of the longitudinal axis 22.In particular, the control body 32 has a corresponding control cone 34 towards its free end face, the respective control surface 20 of which encloses an acute angle of preferably less than 45°, particularly preferably of approximately 30°, with the longitudinal axis 22 of the element material 10.

[0019] The control body 32 is an integral component of the upper end cap 15, which in this respect forms the upper closure part 14. This end cap 15 has an element receptacle 36 for receiving the upper free end of the element material 10 on the front side. The connection between the element material 10 in this upper connection area and the element receptacle 36 is realized via a conventional adhesive bed 38, which is not shown for the sake of simplicity. The control body 32, with its individual, spaced-apart control surfaces 20, opens into an annular surface 40 on its free front side and, starting from its respective inclined control surface 20, merges into a cylindrical shoulder 42 on the adjacent upper side of the end cap 15, which is particularly evident from the illustration in Figure 4, although this shoulder 42 is not absolutely necessary for the function.

[0020] The control body 32 is centrally penetrated by an opening 44 for the flow of fluid, which, as shown in Figure 2, is covered by a valve closing member 46 of a bypass valve 48 in its closed position. The plate-shaped valve closing member 46 of the bypass valve 48 is supported by a compression spring 50, which is integrated into a receiving housing 52 of the bypass valve 48. According to the illustration in Figure 2, fluid flows through the element material 10 from the outside to the inside toward the interior space 26. If the element material 10 is clogged by particle contamination, which is technically referred to as blocking, the fluid flow is guided past the element material 10 on the outer circumference and reaches the inside of the control cone 34 of the control body 32.At the appropriate fluid pressure, the valve closing member 46 is then moved downward against the force of the compression spring 50, thus opening this central opening 44, and the fluid stream passes through the central opening 44 and through web-like passages in the receiving housing 52 to the clean side of the element material 10, i.e., into the interior 26 of the filter element. The receiving housing 52 is designed to be closed at its bottom 54, and the valve closing member 46 is guided telescopically via wall sections into adjacent hollow cylindrical wall sections of the receiving housing 52, which otherwise leaves individual passages free between webs for the flow of fluid.

[0021] If the upper end part 14 and the receiving housing 52 of the bypass valve 48 are formed from plastic parts, for example in the form of plastic injection-molded parts, the receiving housing 52 can be snapped into corresponding wall parts of the upper end part 14 via its upper edge in an elastically flexible manner for a durable fit, but can also be adhesively connected. Within the scope of the connection, the bypass valve 48 protrudes with an axial projection into the interior space 26 of the element material 10 at its upper free end. As can be further seen from Figure 2, the control body 32 is radially penetrated by fluid passages 56, which open outwards into the environment on one side and exit on the other, opposite side in the direction of the valve closing member 46.The individual fluid passages 56 are delimited by web surfaces which extend vertically between the annular surface 40 and the shoulder 42 and in the direction of the adjacent upper side of the upper end part 14 in the form of the corresponding end cap 15 and on the outer circumference side, the individual control webs which extend in a ring-like manner from the interior of the control body 32 to the outside open into the respective inclined control surface 20.

[0022] The control body 32 is arranged coaxially to the longitudinal axis 22 of the element material 10 and projects axially by a predeterminable amount beyond the assignable end cap 15 in the form of the upper end part 14, wherein the respective projection is smaller, preferably by one third, than the diameter of the control body 32 at its base-side transition point to the upper end part 14 in the form of the upper end cap 15. At least the upper side of the respective end cap 15 in the form of the upper end part 14 as well as the control body 32 itself with its control cone 34 are designed as a rib construction with a plurality of individual ribs, wherein the inclined individual ribs of the control body 32 form the respective control surface 20.Such a rib construction is not absolutely necessary, but leads overall to a stiffening of the upper end part 14, so that erection forces can be safely absorbed during the automatic erection of the filter element, starting from its installation position according to Figure 3 into its vertical functional position according to Figure 4. In particular, in this way, a reliable introduction of force into the element material 10 of the filter element as a whole is achieved in the area of ​​the control body 32, to which the inner support structure in the form of the support tube 28, which is integrated at the end into the upper end cap 15, also contributes.

[0023] The installation drawing in Figure 5 provides further details of the spherical bearing 28 as a whole, as follows. The lower end cap 13 in the form of the lower closure part 12 is fitted with its outer tubular body 60 onto the inner tubular body 62 of the nozzle-shaped connecting part 18, with the bearing 24 being clipped to the adjacent bearing surfaces 64, 66 due to elastic resilience, in particular of the tubular body 62 free-standing on the contact surface 68. Due to the contact of the convex bearing surface 64 against the concave bearing surface 66, the spherical bearing 24 is formed in the manner of a ball joint between the lower end cap 13 as part of the lower closure part 12 and the connecting part 18 with its external thread 16.The end part 12 forming the lower end cap 13 in turn has a further element receptacle 70 for receiving the lower end of the element material 10, which is firmly connected to the lower end cap 13 via an adhesive bed 71 (not shown). Typically, the spherical bearing 24 with its two tubular bodies 60, 62 has a locking device 72 that protects against rotation when screwing the filter element into an associated connection housing between the two tubular bodies 60, 62. Furthermore, the undesired exceeding of a predeterminable maximum deflection between the two tubular bodies 60, 62 with their spherical bearing surfaces 64, 66 is prevented. Further details of such a locking device can be found, for example, in DE 10 2018 009 187 A1.

[0024] As can be seen particularly from the installation situation according to Figure 3, a housing 74 is provided for the installation of the filter element as a whole. It consists of a hollow cylindrical housing shell 76, which has a cover part 78 on the top side that is not yet mounted, in particular not screwed on, and a fluid guide part 80 on the base side, which is already screwed onto the outside of the housing shell 76, at one lower free end, via a threaded section 82. The fluid guide part 80 has an inlet 84 for an unfiltered stream and an outlet 86 for the filtered filtrate stream. The inlet 84 is fluid-conductingly connected to an unfiltered stream chamber 88 between the inside of the housing shell 76 and the outer peripheral side of the preferably pleated element material 10.After flowing through the element material 10 and the support tube 28 from the outside to the inside, the filtrate located on the side of the interior space 26 is discharged as a whole via the outlet 86 of the filter device.

[0025] The fluid guide part 80 has a filter element receptacle 90 with an internal thread 92 in the central region 87 of the outlet 86. The nozzle-like filter element receptacle 90 is arranged with its central axis 94 offset from the longitudinal axis 96 of the hollow cylindrical housing shell 76 by a predeterminable angle, so that effective installation protection as a counterfeit protection is created via the fluid guide part 80 of the housing 74, and conventional filter elements cannot be exchanged into the housing construction shown in Figure 3. In particular, if the cover part 78 were to be screwed on along an external thread 98 at the upper end of the housing shell 76, the cover part 78 would collide with the upper element end 100 of the filter element, so that screwing on or otherwise connecting the cover part 78 to the housing 74 is not possible at all.

[0026] This is where the invention comes into play when a conventional screw-in socket 102 as a one-piece component of the lower end cap 13 as the lower closure part 12 is replaced by an element solution as shown in Figures 1 and 2. In this case, the filter element according to Figures 1 and 2 is again brought into an installation position in which the element is screwed into the inclined filter element receptacle 90 on the bottom side as a counterfeit protection, and in this respect too, an offset then results between the central axis 94 and the longitudinal axis 96 of the housing shell 76. Accordingly, the upper element closure 100 also takes up a position for the element designs according to Figures 1 and 2, comparable to that shown in Figure 3.

[0027] However, the component of the element end part 100 according to the invention is now the already described control body 32 with its control cone 34, formed from the individual segmented and inclined control surfaces 20 with the predeterminable angle of inclination x. If the cover part 78 is now screwed onto the housing shell 76 at the head, as indicated in Figure 3, guide parts 104 on the inner circumference of the cover part 78 slide onto the inclined control surfaces 20 and during the screwing-on movement this leads, thanks to the spherical bearing 24, to an erecting movement of the filter element as a whole into its functional position, as shown in Figure 4. To illustrate this, the upper element end of a conventional filter element was replaced by the control body 32 according to the invention.In this functional position, the longitudinal axis 96 of the housing shell 76 then runs coaxially to the central longitudinal axis 22 of the filter element as a whole; with the central axis 94 remaining inclined relative to the bottom-side filter element receptacle 90 in the fluid guide part 80.

[0028] The aforementioned guide parts 104 in the cover part 78 are preferably adapted to the course of the individual control surfaces 20, so that a vertical alignment in the operating or functional position according to the illustration in Figure 4 preferably results. The corresponding erecting movement for the filter element from the installed position according to Figure 3 into the operating or functional position according to Figure 4 takes place via the aforementioned control surfaces 20 of the control body 32 on the upper end cap 15, quasi automatically and continuously by progressively screwing on the cover part 78. In particular, the erecting movement can preferably take place such that the filter element is aligned vertically according to the illustration in Figure 4 and that there is an equal radial distance between the outer circumference of the element material 10 and the inner circumference of the housing shell 76.Due to the self-locking, spherical bearing 24, this vertical functional position is maintained even during filter operation.

[0029] The already mentioned Figure 5 shows the relevant installation situation according to Figure 4 in an enlarged view. If, as shown in Figure 5, the connecting part 18 with its external thread 16 is screwed flush into the internal thread 92 of the filter element holder 90, the connecting part 18 maintains an axial distance from an annular shoulder 106 on the filter element holder 90 at its free lower end. For the position shown, the filter element holder 90 has a raised shoulder 106 on the left side as viewed in the direction of Figure 5, which is smaller on the right side, so that the inclined position on the top side of the filter element holder 90 is an inevitable result.On the opposite upper side, the connecting part 18 has a transversely extending contact surface 108 as a closure, which is an integral part of the connecting part 18 and is arranged approximately centrally between the external thread 16 and the tubular body 62 with its convex bearing surface 64. In this respect, the contact surface 108 is wider in diameter than the external thread 16 and, when the connecting part 18 is fully screwed into the filter element receptacle 90, the contact surface 108 is supported with its lower free end on an upper front edge 110 of the nozzle-shaped filter element receptacle 90 as its upper side.

[0030] Figure 5 also clearly shows the different arrangements of the axis guides 94; 22, 96 between the components in the operating or functional position. Between the underside of the contact surface 108 and the adjacent external thread 16, a receiving space 112 may be provided for a ring seal (not shown), which separates the unfiltered area from the filtrate area inside the housing 74.

[0031] In the operating or functional position shown in Figures 4 and 5, the lower end cap 13, which is pivotally held by the pivot bearing or spherical bearing 24, rests with its contact surface 109 on the inclined upper side of the contact surface 108, so that the end cap 13, with its contact surface 109, is aligned horizontally, which ensures increased stability for the overall construction, particularly during filtration operation. Due to this support, the spherical bearing 24 is also relieved of forces during filtration operation. While the lower connecting part 18 is tilted to provide protection against installation or counterfeiting, the spherical bearing 24 compensates for this tilt, and by means of at least one control surface 20 on the opposite side of the element, the filter element as a whole is automatically raised from an installed position into an operating position.This has no equivalent in the state of the art.

Claims

Patent claims 1 . Filter element with an element material (10) which delimits an interior space (26) and extends between two end parts (12, 14), of which one end part (12) has a spherical bearing (24) and a fluid-conducting connecting part (18) which opens out in the direction of the interior space (26), characterized in that the other end part (14) has at least one control surface (20) which, when inactive, holds the element material (10) in an installed position relative to the connecting part (18) and which, when activated, brings the element material (10) relative to the connecting part (18) into a functional position which is collision-free for the filter element by means of the spherical bearing (24).

2. Filter element according to claim 1, characterized in that the respective control surface (20) is part of a control body (32) which projects axially into the environment by a predeterminable projection beyond the element material (10) and which has a predeterminable inclination, the angle of inclination (x) of which is selected such that when the control body (32) is actuated, the element material (10) self-lockingly assumes its predetermined, collision-free functional position by means of the spherical bearing (24).

3. Filter element according to claim 1 or 2, characterized in that the control body (32) has a control cone (34) towards its free end face, the at least one control surface (20) of which encloses an acute angle (x) of preferably less than 45°, particularly preferably of 30°, with a longitudinal axis (22) of the element material (10).

4. Filter element according to one of the preceding claims, characterized in that the control body (32) is an integral part of an end cap (15) which has an element receptacle (36) for the frontal reception of the element material (10) and in that the control body (32), starting from its respective inclined control surface (20) in the direction of the adjacent upper side of this end cap (15), merges into a cylindrical shoulder (42).

5. Filter element according to one of the preceding claims, characterized in that the control body (32) is penetrated centrally by an opening (44) for the flow of fluid, which opening can preferably be covered by a valve closing member (46) of a bypass valve (48) which is received in the interior (26) of the element material (10) and is connected, preferably in a latching manner, to the adjacent one end cap (15).

6. Filter element according to one of the preceding claims, characterized in that the control body (32) is radially penetrated by fluid passages (56) which open into the environment on one side and in the direction of the valve closing member (46) on the other opposite side.

7. Filter element according to one of the preceding claims, characterized in that the control body (32) is arranged coaxially to the longitudinal axis (22) of the element material (10), protrudes axially by a predeterminable length beyond the assignable end cap (15), which is smaller, preferably by half, particularly preferably by one third smaller, than the diameter of the control body (32) at its base-side transition point to its end cap (15).

8. Filter element according to one of the preceding claims, characterized in that both at least the upper side of the one end cap (15) and the control body (32) itself are designed as a rib construction with a plurality of individual ribs, and that the inclined individual ribs of the control body (32) form the respective control surface (20).

9. Filter element according to one of the preceding claims, characterized in that the connecting part (18) of one end part (12) has a threaded section (16) and a contact surface (108) running transversely thereto, and that the further end cap (13) of the element material (10) has a further contact surface (109) which, in the functional position, pivots by means of the spherical bearing (24) and is partially supported on the one contact surface (108).

10. Filter element according to one of the preceding claims, characterized in that the spherical bearing (24) has a fixable bearing shell with a convex bearing surface (64) on the connecting part (18), opposite which a shell part with a concave bearing shell (66) of the end cap (12) with the element material (10) is movably guided.

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