FILTER ELEMENT WITH VALVE DEVICE

Description

Technical field

[0001] The invention relates to a filter element for filtering a fluid, in particular a liquid, especially for filtering hydraulic fluid or engine oil, with a hollow cylindrical filter bellows through which radial flow can occur. State of the art

[0002] DE 10 2010 054 349 A1 discloses a replaceable filter element for filtering a liquid, in particular for filtering the oil in the oil circuit of an internal combustion engine. The filter element comprises a filter bellows for the flow of the liquid to be filtered and a cylindrical central tube for supporting the filter element. A screen is attached to the central tube, which closes an end opening of the filter element, and the screen has a screen body that is sealed along its circumference to the central tube or the end plate.

[0003] US 2013327429 A1 discloses a bypass valve with adjustable flow resistance for a device through which a liquid medium flows, for example, a filter element. The valve comprises a seat and a body that is pre-tensioned closed and is movable in the opening direction by a pressure differential of the fluid medium between the inlet and outlet sides of the valve when the pressure differential exceeds a threshold value. A bypass flow path connects the inlet side to the outlet side through the seat. The bypass valve includes a screen arranged in the bypass flow path. The valve body has two different opening positions that depend on the pressure differential of the fluid medium.The entire cross-section of the bypass flow path is covered by the screen in a first valve body opening position with a lower pressure difference and is released with a screen-free bypass flow path cross-section in a second valve body opening position with a larger pressure difference.

[0004] From EP 1 199 093 A1, a filter element with a bypass valve is known, wherein the filter element has a sieve element for supporting the closing spring of the valve. Further filter elements with a bypass valve are known from JP H09 144 522 A and DE 22 56 436 A1. Disclosure of the invention

[0005] One objective of the invention is to create a cost-effective filter element with a valve device and a sieve.

[0006] The aforementioned problem is solved according to one aspect of the invention by a filter element for filtering a fluid, in particular a liquid, comprising at least one hollow cylindrical filter bellows, radially permeable, which is arranged on a central tube with a longitudinal axis and which is permeable to the fluid from a radially outer raw fluid side to a radially inner clean fluid side, wherein the filter bellows is closed at a first end face by a first end plate and at a second end face by a second end plate, wherein the first end plate has an opening with a valve assembly which is arranged inside the central tube and which can be opened by hydraulic pressure from the raw fluid side, wherein the valve assembly comprises a valve body and a valve cage as well as a sieve.wherein the valve body is movable in the valve cage along the longitudinal axis and, in a pressureless state, is pressed against a valve seat arranged in the valve cage by means of a spring, wherein the screen is arranged on the valve cage and the screen separates an interior of the valve assembly from the clean fluid side, wherein the valve cage is arranged on a support body connected to the central tube.

[0007] Favorable embodiments and advantages of the invention will become apparent from the further claims, the description and the drawing.

[0008] According to one aspect of the invention, a filter element for filtering a fluid, in particular a liquid, is proposed, comprising at least one hollow cylindrical filter bellows through which the fluid can flow. The filter bellows is arranged on a central tube with a longitudinal axis and is open to flow from a radially outer raw fluid side to a radially inner clean fluid side. The filter bellows is closed at a first end face by a first end plate and at a second end face by a second end plate. The first end plate has an opening with a valve assembly located inside the central tube, which can be opened by hydraulic pressure from the raw fluid side.The valve assembly comprises a valve body, a valve cage, and a strainer. The valve body is movable within the valve cage along its longitudinal axis and, in a depressurized state, is pressed against a valve seat located within the valve cage by a spring. The strainer is attached to the valve cage and separates an interior area of ​​the valve assembly from the clean fluid side. The valve cage is mounted on a support body connected to the central tube.

[0009] Advantageously, the valve device separates the raw fluid side from the clean fluid side of the filter element.

[0010] The filter element can be replaceable within a filter housing or permanently installed in a so-called spin-on filter system. The filter element comprises a filter bellows, two end discs, a central tube, and a valve assembly that acts as a bypass valve and simultaneously forms a safety screen assembly with a screen. The fluid to be filtered flows radially through the filter element from the outside to the inside. The bypass valve opens at a defined differential pressure. At this point, the fluid pressure lifts a valve body from a sealing seat and presses it against a coil spring. The fabric screen is cylindrical and can be at least partially overmolded within a valve cage during a casting process.

[0011] The sieve can be made from a standard sieve fabric. Plastic or metal sieves are both possible. A nonwoven fabric can also be used, for example. A mesh size of between 100 µm and 500 µm is advantageous.

[0012] Integrating the valve assembly and filter allows for more cost-effective manufacturing of the filter element, as bonding processes can be carried out more efficiently with less material. This also allows for fewer components or their more economical production. Plug-in or snap-fit ​​connections between the valve assembly and the center tube and / or end plate enable component reusability. Improved component accessibility further reduces manufacturing costs.

[0013] According to a favorable design of the filter element, the support body and the central tube can be formed as a single piece. This reduces manufacturing costs for both components.

[0014] According to a favorable design of the filter element, the valve cage can be connected to the central tube and / or the support body by means of a snap-fit ​​connection, a latching connection, a plug connection, and / or a screw connection. Using such connection methods allows the valve cage to be disassembled without damage, thus ensuring reusability for maintenance purposes.

[0015] According to a favorable design of the filter element, the valve cage can have guide elements on its inner surface for axially guiding the valve body. In this way, reliable operation of the valve body can be advantageously achieved.

[0016] In a favorable design of the filter element, a gap can be formed between the screen and the outer diameter of the valve body. This ensures that the screen does not impair the valve body's range of motion, which is essential for its proper function.

[0017] According to a favorable design of the filter element, the valve cage can be pressed, glued, and / or screwed into the opening of the first end plate. This ensures a secure and permanent connection between the valve cage and the first end plate.

[0018] According to a favorable design of the filter element, the valve cage and the first end plate can be formed as a single unit. This allows the end plate and valve cage to be produced cost-effectively in one manufacturing step, for example, by plastic injection molding. Polyamide (PA) can be advantageously used as a material. For higher strength, a fiber-reinforced plastic can also be used.

[0019] According to a favorable design of the filter element, the filter bellows and / or the central tube can be bonded to the end plates. In particular, the filter bellows and / or the central tube can be encapsulated in the end plates, which are made of a hard plastic – for example, PA – using a liquid adhesive. Such a bonding process ensures a secure and reliable connection between the filter bellows and / or central tube and the end plates, and also represents a cost-effective manufacturing process.

[0020] According to a favorable design of the filter element, the filter element can be operated with the valve device against the direction of gravity. Thus, depending on the application, the filter element can also be operated upside down.

[0021] According to a favorable design of the filter element, at least the first end plate can be designed as a foil end plate, and the central tube and / or the valve cage can be connected to the first end plate by means of a plug connection. Foil end plates represent a cost-effective alternative to the production of plastic end plates in filter elements.

[0022] According to a favorable design of the filter element, the plug connection can be detachable. This advantageously ensures the reuse of the individual components.

[0023] According to a favorable design of the filter element, the valve cage can be designed as a hollow cylinder with through-openings covered by the screen. Thus, when the valve body opens the valve passage under fluid overpressure, the fluid can flow efficiently through the screen, filtered, into the interior of the filter element, which represents the clean fluid area of ​​the filter element.

[0024] According to a favorable design of the filter element, the support body can have axially extending ribs which serve to guide the valve cage. This enables secure mounting of the valve cage to the support body, as the ribs can, for example, advantageously center the valve cage during assembly.

[0025] In a favorable design of the filter element, the support body can have a circumferential shoulder that acts as a spring bearing, supporting the spring when the valve assembly is properly installed. This ensures a secure fit of the spring during operation of the filter element, thereby guaranteeing the reliable function of the valve assembly.

[0026] According to a favorable design of the filter element, the support body can be connected to the central tube via radially extending ribs. This connection of the support body to the central tube via individual ribs ensures a free flow of the fluid filtered through the sieve into the clean fluid section of the filter element. Brief description of the drawings

[0027] Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations. The following are shown as examples: Figure 1 shows a partially cutaway side view of a filter element for filtering a fluid, in particular a liquid, according to an embodiment of the invention; Figure 2 shows a cutaway isometric view of the filter element according to Figure 1 Figure 3 shows an enlarged view of a valve assembly of the filter element without a filter bellows; and Figure 4 shows a valve cage of the filter element according to Figure 1 in isometric representation. Designs the invention

[0028] In the figures, identical or similar components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0029] Figure 1 shows a partially cutaway side view of a filter element 10 for filtering a fluid, in particular a liquid, according to an embodiment of the invention, while in Figure 2 a sectioned isometric representation of filter element 10 according to Figure 1 shown. Figure 3 Figure 1 shows an enlarged representation of a valve assembly 20 of the filter element 10 without filter bellows 12. Figure 4 is a valve cage 26 of the filter element 10 after Figure 1 shown in isometric representation.

[0030] The filter element 10 comprises a hollow cylindrical filter bellows 12, through which the fluid flows, and which is arranged on a central tube 18 with a longitudinal axis L. During normal operation, the filter bellows 12 is permeated by fluid flow from a radially outer raw fluid side 50 to a radially inner clean fluid side 52. The filter bellows 12 is closed at a first end face 13 by a first end plate 14 and at a second end face 15 by a second end plate 16. The second end plate 16 has a collar-shaped protrusion 42, which, when installed in a filter housing (not shown), ensures a seal between the raw fluid side 50 and the clean fluid side 52.

[0031] The first end disk 14 has an opening 44 with a valve assembly 20, which is arranged inside the central tube 18. The valve assembly 20 comprises a valve body 22, a valve cage 26, and a screen 28. The valve body 22 can move within the valve cage 26 along the longitudinal axis L and, in a depressurized state, is pressed against a valve seat 30 located in the valve cage 26 by means of a spring 24. Thus, the valve assembly 20 constitutes a check valve.

[0032] The valve body 22 has a valve cone 62 which seals against the valve seat 30 and which is connected to four wing-like ribs 60 arranged in a cross shape, as shown in particular in Figure 3 The valve cone 62 can, for example, be designed as part of a truncated cone or as part of a spherical cap to ensure a reliable seal on the valve seat 30.

[0033] The valve seat 30 is arranged on the side of an opening 66 of a cover plate 64 of the valve cage 26 facing the interior 38 of the valve assembly 20, as shown in the Figures 3 and 4 recognizable.

[0034] The sieve 28 is arranged on the valve cage 26 and separates an interior 38 of the valve assembly 20 from the clean fluid side 52. The valve cage 26 is arranged on a support body 32 connected to the central tube 18.

[0035] The valve assembly 20 separates the raw fluid side 50 from the purified fluid side 52 and can be opened by hydraulic pressure from the raw fluid side 50. The valve assembly 20 thus functions as a bypass valve if the hydraulic pressure on the raw fluid side 50 becomes too high. In this case, the valve assembly 20 opens and raw fluid can flow into the interior 38 of the valve assembly 20.

[0036] The support body 32 can be formed in one piece with the central tube 18, as in the section shown in Figure 1 as can be seen in the illustrated embodiment and is connected to the central tube 18 via radially extending ribs 40, as shown in Figure 2 recognizable.

[0037] The valve cage 26, which is designed as a hollow cylinder with through-openings 58, as particularly in the Figures 3 and 4 As can be seen, the sieve 28 is located on its inner surface 46. At least the through-openings 58 can be covered by the sieve 28.

[0038] The valve cage 26 can be placed onto the support body 32, which is pin-shaped, through the opening 44 of the first end disk 14 during the assembly of the valve assembly 20 with the valve body 22 inserted and the spring 24 arranged above it.

[0039] The support body 32 can be used for this purpose, as in the illustrated embodiment, particularly in Figure 3The valve assembly 20 can be identified as having a circumferential shoulder 34 as a spring bearing, which serves to support the spring 24 when the valve assembly 20 is installed as intended. The shoulder 34 allows the spring 24 to be advantageously shorter.

[0040] Furthermore, the support body 32 can have ribs 36 extending in the axial direction L, which serve to guide the valve cage 26 during installation and also provide a firm fixation of the valve cage 26 in the radial direction, which is advantageous for robust operation of the filter element. The illustrated embodiment, for example, has four ribs 40, which are arranged in a cross-shaped cross-section. In the illustrations of the Figures 1 to 3 Only two ribs 40 are visible in each image. A third rib 40 is partially visible. The fourth rib 40 is not shown in the images.

[0041] Afterwards, the valve cage 26 can be connected to the central tube 18 and / or the support body 32 at least by means of a snap connection and / or a snap connection and / or a plug connection and / or a screw connection.

[0042] The valve cage 26 can be pressed and / or glued and / or screwed into the opening 44 of the first end disk 14.

[0043] In an alternative embodiment, the valve cage 26 can be formed in one piece with the first end disk 14.

[0044] The valve cage 26 has 46 guide elements 48 on its inner surface for axially guiding the valve body 22. These guide elements 48, which can be designed as ribs, can also advantageously serve to stiffen the valve cage 26. Furthermore, a gap 54 can thus be advantageously formed between the screen 28 and an outer diameter 56 of the valve body 22.

[0045] The filter bellows 12 and / or the central tube 18 can advantageously be bonded to the end plates 14, 16, which can, for example, be made of plastic. In particular, the filter bellows 12 and / or the central tube 18 can, for example, be encased in the end plates 14, 16 using a liquid adhesive. The filter bellows 12 and central tube 18 can also, for example, be advantageously encased in polyurethane (PU) if the end plates 14, 16 are designed as solid end plates 14, 16.

[0046] In an alternative embodiment, at least the first end disk 14 can also be designed as a foil end disk. In this case, the central tube 18 and / or the valve cage 26 can be connected to the at least first end disk 14 by means of a plug connection. In such an embodiment, the rigid end disks 14, 16 of the [unclear] are omitted. Figures 1 to 3 illustrated embodiment.

[0047] In particular, the plug connections of the central tube 18 and / or valve cage 26 can be designed to be detachable. This advantageously ensures the reuse of these internal components of the filter element 10 in the event of maintenance, for example, when replacing them due to a loaded filter bellows 12.

[0048] In the Figures 1 to 4 In the illustrated embodiments, the filter element 10 is oriented such that the valve assembly 20 is arranged downwards in the direction of gravity g. However, it is also possible in principle for the filter element 10 with the valve assembly 20 to be operated against the direction of gravity g. Reference sign

[0049] 10 Filter element 12 Filter bellows 13 First end face 14 First end plate 15 Second end face 16 Second end plate 18 Center tube 20 Valve assembly 22 Valve body 24 Spring 26 Valve cage 28 Screen 30 Valve seat 32 Support body 34 Shoulder 36 Rib 38 Interior 40 Rib 42 Collar-shaped protrusion 44 Opening 46 Inside 48 Guide element 50 Raw fluid side 52 Clean fluid side 54 Gap 56 Outer diameter 58 Through opening 60 Blade 62 Valve cone 64 End plate 66 Opening L Axial direction g Gravity direction

Claims

1. A filter element (10) for filtering a fluid, in particular a liquid, comprising at least one hollow cylindrical filter bellows (12) through which fluid can flow radially, which is disposed on a central tube (18) with a longitudinal axis (L) and through which the fluid can flow from a radially external raw fluid side (50) to a radially internal clean fluid side (52), wherein the filter bellows (12) is closed at a first front face (13) by a first end disc (14) and at a second front face (15) by a second end disc (16), wherein the first end disc (14) features an opening (44) with a valve device (20) which is disposed inside the central tube (18), and which can be opened by hydraulic pressure from the raw fluid side (50), wherein the valve device (20) features a valve body (22) and a valve housing (26) as well as a sieve (28), wherein the valve body (22) is movable in the valve housing (26) along the longitudinal axis (L) and, in a pressureless state, is pressed by means of a spring (24) against a valve seat (30) disposed in the valve housing (26), wherein the sieve (28) is disposed on the valve housing (26) and the sieve (28) separates an interior space (38) of the valve device (20) from the clean fluid side (52), characterized in that the valve housing (26) is disposed on a support body (32) connected to the central tube (18).

2. The filter element according to claim 1, wherein the support body (32) is formed integrally with the central tube (18).

3. The filter element according to claim 1 or 2, wherein the valve housing (26) is connected to the central tube (18) and / or to the support body (32) at least by means of a snap-in connection and / or a snap-fit connection and / or a plug-in connection and / or a screwed connection.

4. The filter element according to one of the preceding claims, wherein the valve housing (26) features guide elements (48) on its interior side (46) for axial guidance of the valve body (22).

5. The filter element according to one of the preceding claims, wherein a gap (54) is formed between the sieve (28) and an external diameter (56) of the valve body (22).

6. The filter element according to one of the preceding claims, wherein the valve housing (26) is pressed and / or glued and / or screwed into the opening (44) of the first end disc (14).

7. The filter element according to one of the claims 1 to 5, wherein the valve housing (26) is formed integrally with the first end disc (14).

8. The filter element according to one of the preceding claims, wherein at least one of the end discs (14, 16) is made of plastic material and the filter bellows (12) and / or the central tube (18) is glued to the at least one end disc (14, 16) made of plastic material, in particular wherein the filter bellows (12) and / or the central tube (18) is / are cast into the end disc (14, 16) by means of a liquid adhesive.

9. The filter element according to one of the preceding claims, wherein the filter element (10) can be operated with the valve device (20) against a direction of gravity (g).

10. The filter element according to one of the preceding claims, wherein at least the first end disc (14) is designed as a foil end plate and the central tube (18) and / or the valve housing (26) are connected to the first end disc (14) by means of an in particular detachable plug-in connection.

11. The filter element according to one of the preceding claims, wherein the valve housing (26) is designed as a hollow cylinder with through-openings (58) covered by the sieve (28).

12. The filter element according to one of the preceding claims, wherein the support body (32) features ribs (36) extending in the axial direction (L), which serve to guide the valve housing (26).

13. The filter element according to one of the preceding claims, wherein the support body (32) features a circumferential shoulder (34) as a spring bearing and which serves to support the spring (24) when the valve device (20) is mounted as intended.

14. The filter element according to one of the preceding claims, wherein the support body (32) is connected to the central tube (18) via radially extending ribs (40).