Filter unit

Abstract

A filter element (30) comprises a tubular filter medium (33) having a central axis (A) and a support plate (32) fixed to one end of the filter medium (33), wherein the support plate (32) comprises coupling teeth (34), the coupling teeth (34) having a stem (340) and a coupling head (341), the stem (340) protruding from a surface of the support plate (32) opposite to the filter medium (30), the coupling head (341) protruding radially outwards relative to the central axis (A) in a cantilever form from the stem (340), the coupling head (341) comprising at least two free, opposite edges (3412, 3413) located at a distal end relative to the central axis (A), the at least two edges (3412, 3413) being at different distances from the central axis (A) of the filter medium.

Description

Technical Field

[0001] The present invention relates to a filter unit, a filter element, and a support body, which is designed to support the filter element inside the filter unit.

[0002] The present invention mainly relates to a filter, which is suitable for use in a vehicle or in any case for fluids of an internal combustion engine, such as fuel (diesel or gasoline), oil, urea, water, air leakage, or combustion-supporting air in the field of electric motors (such as the automotive field) for light or heavy applications, etc. Background Art

[0003] As is well known, filtration in the field of electric motors or industry is usually achieved through a filter unit, which includes a housing and a filter element. The housing has an inlet for the fluid to be filtered and an outlet for the filtered fluid. The filter element is adapted to define a communication chamber, which has an inlet for the fluid to be filtered and is fixed to the housing through a support body and a quick-connection system (coupler) for connecting the filter element to the support body.

[0004] In this way, the fluid flowing from the inlet to the outlet of the filter is forced to pass through the filter medium, which blocks any impurities present in the fluid. Increasingly demanding filtration requirements (such as the ability to block dirt and not cause excessive pressure drop due to the filter element) require higher-performance filter elements. To ensure high filtration capacity, it is necessary to manufacture high-performance filter elements. For example, such high-performance filter elements have a larger filtration surface (without affecting other functions already present in the filter unit). This means that, for example, it is necessary to produce filter elements with a greater length and / or diameter, which results in a reduction in the available space for implementing a reliable connection system that is suitable for allowing sufficient arrangement of auxiliary components required for the normal operation of the filter unit. These aspects make it difficult to apply standard solutions, where manufacturers need to design and implement customized solutions, resulting in an increase in the costs and equipment used.

[0005] In addition, during the recovery and maintenance operations of the filter unit, if the technician involved in the filter element replacement decides to install an alternative (non-original or uncertified) filter element, the efforts made by the manufacturer to make the filter unit more effective and have higher performance may sometimes be hindered. For the above reasons, filter unit manufacturers need to provide available solutions that can minimize the risk of installing non-original parts, which in any case do not meet the filtration and functional requirements of the preset original components.

[0006] The following lists further requirements felt by people in the field of the above-mentioned filter unit (including the filter element and the support body as described above).

[0007] For example, the needs felt in connection with these types of filter units are to maintain their functionality while mainly simplifying the molds for the plastic parts of the filter element, the support body, and the filter unit, and in addition to optimize the use of the available space within the filter unit, i.e., within the support body.

[0008] In particular, there is a felt need to allow for the optimization of the peripheral space around the central axis of the filter element and / or the support body, which peripheral space is simultaneously used to obtain the seating for the filter element and the centering and angular positioning elements for the filter element relative to its support body.

[0009] In fact, depending on the specific application, the space around the central axis is used for the installation of auxiliary components (such as bypass valves, sensors, heaters, drain plugs, and sealing elements that separate the dirty side and the clean side of the filter unit), so the space reserved for the coupling means between the filter element and the support body is usually a limited space, or in any case, a space subject to strict design constraints.

[0010] In addition, the needs felt in connection with this type of filter unit are to extend the applicability of the coupling system between the support body and the filter element to filter units having different sizes and / or heights.

[0011] A further need in connection with this type of filter unit is to vary and / or reduce the number of coupling bodies (teeth and corresponding seats) that detachably engage the filter element to the support body without compromising the coupling strength, depending on the specific application.

[0012] Further production needs of the prior art are related to the need to reduce production costs, simplify the design and assembly.

[0013] The object of the present invention is to meet the above needs of the prior art, for example, in a simple, reasonable, and low-cost solution.

[0014] These objects are achieved by the features of the present invention as claimed in the independent claims. The corresponding claims subordinate to the independent claims outline the preferred and / or particularly advantageous aspects of the present invention. Summary of the Invention

[0015] The present invention particularly provides an available filter element, which includes a tubular filter medium having a central axis and a support plate fixed to one end of the filter medium, wherein the support plate includes coupling teeth, the coupling teeth having a rod and a coupling head, the rod protruding from the surface of the support plate opposite to the filter medium, and the coupling head protruding from the rod in a cantilever form outwardly in the radial direction relative to the central axis, wherein the coupling head includes at least two free edges that are opposite and located distally relative to the central axis, and the at least two free edges are at different distances from the central axis of the filter medium.

[0016] Based on this solution, all the requirements of the known art as described above may be met. In particular, the mold for forming the support plate may be simplified while maintaining the functionality of the filter element and allowing a reduction in the production costs associated therewith. Advantageously, the edges of the connector may be rounded, thereby correspondingly defining a cylindrical portion, the axis of which is parallel to and eccentric with respect to the central axis.

[0017] Furthermore, the connector of the connecting teeth may include two opposite sides that circumferentially define the connector, wherein the planes in which the two opposite sides are located intersect at an intersection line that is parallel and eccentric with respect to the central axis of the filter medium, and the connecting teeth are located between the central axis and the intersection line.

[0018] Based on this technical solution, the ends of the connecting teeth face outward from the support plate.

[0019] Preferably, the connector of the connecting teeth may include a first forming surface that is flat and perpendicular to the central axis of the filter medium and is proximal to the support plate. The first forming surface is defined by at least four vertices, two of which are distal with respect to the central axis and two of which are proximal with respect to the central axis. The first forming surface and the two edges distal with respect to the central axis meet at the two vertices distal with respect to the central axis.

[0020] Advantageously, the connector may include a second forming surface that is distal with respect to the support plate. Preferably, the second forming surface is also perpendicular to the central axis.

[0021] Another aspect of the present invention provides a connector of a connecting tooth that may include a positive forming surface distal with respect to the central axis. The positive forming surface radially defines the first and second forming surfaces. The positive forming surface is adapted to connect the two edges distal with respect to the central axis, and the positive forming surface has, for example, a concave portion that is between the two edges distal with respect to the central axis and is adapted to connect the two edges distal with respect to the central axis, and has a concave surface facing away from the central axis. Preferably, the rod of the connecting tooth is elastically bendable in the radial direction.

[0022] Based on this solution, connecting teeth suitable for snap-fitting with corresponding seats may be obtained.

[0023] In one embodiment, the connector may include two additional edges proximal with respect to the central axis, which are, for example, also at different (or optionally, the same) distances from the central axis of the filter element.

[0024] The joint head of the coupling tooth may further include a side portion, the side portion including one of two edges located distally relative to the central axis of the joint head, the nearest additional edge of two additional edges located proximally relative to the central axis, and a side surface that circumferentially defines the side portion and is between the edge and the additional edge, wherein the side portion projects circumferentially and beyond the circumferential length of the rod, and includes an additional formed front surface that is located proximally relative to the central axis and radially defines the side portion, wherein the additional formed front surface is adapted to connect the additional edge contained in the side portion and the concave edge of the side portion, and the concave edge is aligned with the rod.

[0025] Advantageously, for example radially and / or axially, the side portion is elastically bendable, thereby reducing the need to make the rod (very) bendable, reducing any stress on the coupling tooth, and thus reducing the risk of unwanted damage to the coupling tooth.

[0026] This side portion defines the rear side of the coupling tooth and is capable of defining an adjacent area for the coupling tooth and thus for the filter element, which adjacent area is used to correctly position the filter element within the filter unit or to position the filter element within the filter unit relative to a support body that supports the filter element relative to a setting.

[0027] The third edge where the second formed surface meets the formed front surface located distally relative to the central axis may be rounded, and the third edge radially defines the first and second formed surfaces and connects the two edges located distally relative to the central axis.

[0028] In this way, the rounded corner defines a starting and supporting area for axially inserting the coupling tooth into the corresponding seat.

[0029] At the fourth edge where the first formed surface meets the positive formed surface, it may be replaced with a sharp edge at a right angle.

[0030] On the other hand, the present solution allows for a more reliable anti-slip surface for the coupling tooth when the coupling tooth is inserted into its specific seat.

[0031] For the same purpose as above, another aspect of the present invention provides a support body for a filter element, the support body including a disc-shaped (bottom) wall and a formed handle, the disc-shaped wall having a central axis, the formed handle protruding from the surface of the disc-shaped wall and defining a coupling window, the coupling window being axially defined by two flat formed surfaces and circumferentially defined by two side walls, the two flat formed surfaces being parallel to each other and perpendicular to the central axis, the two side walls being perpendicular to the flat formed surfaces, and the planes in which the two side walls are located intersect at an intersection line that is parallel and eccentric relative to the central axis and located outside thereof.

[0032] Advantageously, in order to facilitate the insertion of the coupling teeth into the windows, the shaped handle may include a prismatic seat that is open at the top and closed at the bottom by the disc-shaped wall of the support body. The axis of the prismatic seat is parallel to the central axis, and the prismatic seat is circumferentially aligned with and adjacent to the corresponding window.

[0033] To improve the centering of the filter element, the shaped handle may have a varying height along its circumference relative to the disc-shaped wall. In particular, the shaped handle may have a minimum height at the circumferential portion where the prismatic seat is obtained relative to the disc-shaped wall.

[0034] Furthermore, for the same above-mentioned purpose, on the other hand, the present invention provides a usable filter unit that includes a support body as described above and a filter element as described above, wherein the coupling teeth of the filter element are adapted to releasably couple to the windows of the support body. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further features and advantages of the present invention will become apparent from the following description given by way of non-limiting example with reference to the accompanying drawings.

[0036] Figure 1 is a longitudinal sectional view of a filter unit according to the present invention;

[0037] Figure 2 is Figure 1 a top view of the support body of the filter unit;

[0038] Figure 3 is along Figure 2 sectional trajectory III-III of;

[0039] Figure 4 is Figure 3 a first axonometric view of;

[0040] Figure 5 is Figure 3 a second axonometric view of;

[0041] Figure 6 is along Figure 3 sectional trajectory VI-VI of;

[0042] Figure 7 is Figure 1 an axonometric view of the filter element of the filter unit;

[0043] Figure 8 is Figure 7 a plan view of XIII of;

[0044] Figure 9 is Figure 7 a side view of;

[0045] Figure 10 is alongFigure 8 Cross-sectional view of the cross-section trajectory X-X;

[0046] Figure 11 is Figure 7 Enlarged view of detail XI;

[0047] Figure 12 is Figure 7 Enlarged view of detail XII;

[0048] Figure 13 is the longitudinal cross-sectional view of the first step of installing the filter element in the support of the Figure 1 filtering unit;

[0049] Figure 14 is the longitudinal cross-sectional view of the second step of installing the filter element in the support of the filtering unit according to the present invention;

[0050] Figure 15a , Figure 15b , Figure 15c and Figure 15d are respectively the cross-sectional views along the Figure 14 cross-section trajectory XV-XV of the corresponding steps of installing the filter element in the support of the filtering unit according to the present invention. Detailed implementation mode

[0051] With particular reference to these drawings, the filtering unit is generally indicated by the reference numeral 10. The filtering unit is suitable for filtering fluids for vehicles or in any case for internal combustion engines, such as fuels (diesel or gasoline) in the field of electric motors, petroleum, urea, water, leakage air or combustion-supporting air.

[0052] The filtering unit 10 includes a housing generally indicated by 20, and the housing is suitable for accommodating and defining a support for at least one filter element 30. The housing 20 in turn includes a cup-shaped body 21 and a cover 22, and the cover 22 is suitable for closing the cup-shaped body 21.

[0053] In the described example, the cover 22 (only the upper cover is shown in Figure 1 ) is generally shaped like a cap and has an (internal) thread that is suitable for being screwed helically into the corresponding (external) thread defined on the opening edge of the cup-shaped body 21.

[0054] The cover 22 defines at least one outlet duct 220 for the filtered fluid and an inlet duct 221 for the fluid to be filtered. In the described example, at least one outlet duct 220 and the inlet duct 221 are provided at the top wall of the cover 22. One of the outlet duct 220 and the inlet duct 221, in the example, is the outlet duct 220, and preferably is located at a central position coaxial with the cover 22, for example, and at least partially protrudes inside the cover 22 through the internally threaded first cylindrical seat 223.

[0055] In the illustrated example, the cup-shaped body 21 defines a support for the filter element 30. The cup-shaped body 21 includes a generally disc-shaped bottom wall 210 and a cylindrical side wall 211. The side wall 211 is centered on the central axis B of the cup-shaped body 21 (which coincides with the spiral axis of the cover 22 towards the cup-shaped body 21).

[0056] In the example, the bottom wall 210 includes a central (cylindrical) depression. A connecting body projects from the bottom wall 210, and here the connecting body is defined by a formed handle 212, for example, surrounding the central depression. The formed handle 212 has at least one or more connecting seats, and each connecting seat is defined by a corresponding window 213.

[0057] In the described example, the cup-shaped body 21, that is, the formed handle 212 projecting from its bottom wall 210, includes a total of three windows 213. For example, these three windows 213 are equidistant from each other (and are arranged along a hypothetical circumference centered on the central axis B).

[0058] Each connecting seat or window 213 is formed at a corresponding arcuate wall 2120 of the formed handle 212.

[0059] In the illustrated example, the arcuate wall 2120 has a cross-section (perpendicular to the central axis of the cup-shaped body 21) that is stretched, for example, along a generally curved longitudinal axis, which approximates one side of an (equilateral) triangle inscribed in the bottom wall 210 of the cup-shaped body 21.

[0060] In the example, the longitudinal axis of the arcuate wall 2120 located in a plane perpendicular to the central axis B of the cup-shaped body 21 is generally arcuate, and the concave surface of the arcuate wall 2120 faces the central axis of the cup-shaped body 21. Each connecting seat is defined by a window 213 that, for example, passes from one side to the other in the transverse direction (i.e., generally radially), and the window 213 is obtained at each arcuate wall 2120 of the formed handle 212.

[0061] For example, the window 213 has a generally rectangular shape (see Figure 4 and Figure 5 the details shown), and is bounded below (where below means closest to the axial portion of the bottom wall 210 of the cup-shaped body 21) by a lower flat forming surface 2130, while being bounded above (where above means farthest from the axial portion of the bottom wall 210 of the cup-shaped body 21) by an upper flat forming surface 2131. For example, the lower flat forming surface 2130 is perpendicular to the central axis B of the cup-shaped body 21, and for example, the upper flat forming surface 2131 is also perpendicular to the central axis B of the cup-shaped body 21 and advantageously overlaps the lower flat surface 2130 in plan view.

[0062] The upper flat forming surface 2131 and, for example, the lower flat forming surface 2130 have a contour shape, for example, a polygon shape, which, for example, has a shape of a generally scalene trapezoid, where the smaller base of the scalene trapezoid is located at the distal end relative to the central axis B of the cup body 21, and the larger base of the scalene trapezoid is located at the proximal end relative to the central axis B.

[0063] The upper flat forming surface 2131 and the lower flat forming surface 2130 have a generally consistent shape and overlap each other in the plan view. Therefore, only the upper flat forming surface 2131 is involved hereinafter, and the features described herein are also the same as those related to the lower flat forming surface 2130.

[0064] The upper flat forming surface 2131 defines at least two vertices 2132, 2133 (see Figure 6 ) that are located at the distal end relative to the central axis B of the cup body 21, and these vertices are at different distances from the central axis B of the cup body.

[0065] Therefore, the first vertex 2132 is at a distance D1 from the central axis B of the cup body 21 (see Figure 6 ), and the distance D1 is less than the distance D2 of the second vertex 2133 from the central axis.

[0066] The lower flat forming surface 2130 also defines two additional vertices 2134, 2135 (see Figure 6 ) that are located at the proximal end relative to the central axis B of the cup body 21, and these additional vertices are at different distances from the central axis B of the cup body.

[0067] Therefore, the first additional vertex 2134 is at a distance D3 from the central axis B of the cup body 21, and the distance D3 is less than the distance D4 of the second additional vertex 2135 from the central axis.

[0068] The window 213 is also circumferentially closed by two side walls 2136, 2137, where the first left side wall 2136 connects the first vertex 2132 (of the upper flat forming surface 2130) and the first additional vertex 2134 (of the lower flat forming surface 2131), and the second right side wall 2137 connects the second vertex 2133 (of the upper flat forming surface 2130) and the second additional vertex 2135 (of the lower flat forming surface 2131).

[0069] The two side walls 2136, 2137 and the lower flat forming surface 2130 are substantially perpendicular and substantially perpendicular to the upper flat forming surface 2131, and the planes in which the two side walls 2136, 2137 are located (ideally) intersect at an intersection line b, which is substantially parallel and eccentric to the central axis B of the cup body 21 and is located outside it.

[0070] In fact, the first side wall 2136 is located proximally relative to the central axis B of the cup-shaped body 21, while the second side wall 2137 is located distally relative to the central axis B of the cup-shaped body 21.

[0071] In fact, each window 213 is inclined relative to the circumferential (tangential) direction (for example, at an acute angle), thus defining a preferred circumferential inlet direction (counterclockwise in the example), which will become more apparent hereinafter.

[0072] Axial prismatic seats 214 are provided laterally of each window 213, particularly on one side thereof (preferably on the side before the window 213 in the preferred circumferential direction), that is, the axis of the prismatic seat 214 is parallel to the central axis B of the cup-shaped body.

[0073] For example, the prismatic seat 214 is circumferentially aligned with and adjacent to the corresponding window 213, for example, adjacent to its second side wall 2137 (i.e., the side wall located distally relative to the central axis B).

[0074] The prismatic seat 214 opens at the top and on one side of its circumferential side (i.e., proximally relative to the circumferential side of the corresponding window 213), while being closed below by the bottom wall 210 and closed on the other side of its circumferential side (i.e., distally relative to the circumferential side of the corresponding window 213) by the closing wall 2140.

[0075] The closing wall 2140 is substantially perpendicular to the bottom wall 210 (parallel to the central axis B), so the closing wall 2140 is inclined so that the plane in which it lies intersects (ideally) the plane in which the first side wall 2136 of the window lies at an intersection line c, which is substantially parallel and eccentric to the central axis B of the cup-shaped body 21 and located outside thereof.

[0076] The prismatic seat 214 (see particularly Figure 6 ) is defined radially by a wall 2142 located distally relative to the central axis B and a wall portion 2143 located proximally relative to the central axis B, and the wall portion 2143 is defined by a protrusion 2141 rising from the bottom wall 210, and the protrusion 2141 is proximally located relative to the central axis B and is back-to-back with respect to the edge of the closing wall 2140 in the circumferential direction towards the corresponding window 213.

[0077] For example, the edge located distally relative to the central axis B of the closing wall 2140 is located at a position where the distance from the central axis B is approximately equal to the distance D2 between the second vertex 2133 and the central axis.

[0078] Therefore, a gap is defined between the free end of the raised protrusion 2141 and the opening side of the prismatic seat 214, and this gap circumferentially limits and communicates with the window 213.

[0079] The forming handle 212 includes a top that defines an upper bearing surface, which presents a profile with different heights relative to the bottom wall 210, wherein the upper bearing surface has a minimum height relative to the bottom wall 210 at the prismatic seat 214 and has a maximum height relative to the bottom wall 210 at each part of the arcuate wall 2120 between the prismatic seat 214 and other components; a generally gradually and continuously changing inclination is provided between the minimum height and the maximum height relative to the bottom wall 210.

[0080] As described above, the filtering unit 10 includes the filter element 30 shown in detail in Figures 8 to 12 which is adapted to be received, for example, coaxially with the housing 20 inside the housing 20 and (as will be better described below) coupled to a support body, which in the described example is defined by the cup-shaped body 21, more particularly by the bottom wall 210 of the cup-shaped body 21.

[0081] The filter element 30 includes a first (upper) support plate 31 and a second (lower) support plate 32, which are fixed to opposite ends of a tubular filter medium 33 having a central axis A, which in the described example is a pleated medium plate that defines and bounds a generally cylindrical inner volume (which can generally be a depth medium plate, etc.).

[0082] The filter element 30, i.e., its filter medium 33, can be axially inserted onto one or more support spark plugs 330, which are inserted into the filter medium 33 and have flow openings for the filtered fluid to pass through. In the described example, this spark plug 330 is fixed (e.g., screwed) to the cover 22 of the housing 20. In the example, the spark plug 330 is fixed to the first cylindrical seat 223.

[0083] The first support plate 31 has a central hole 310 centered on the longitudinal axis A of the filter medium 33.

[0084] In particular, the first support plate 31 has a generally cylindrical central stem 311, which defines and axially extends the central hole 310.

[0085] The central stem 311 is adapted to (internally) support the first annular gasket 312.

[0086] In use, the central stem 311 and the corresponding first annular gasket 312 are adapted to be sized and generally inserted onto the outer region of the spark plug 330, which is screwed onto the first cylindrical seat 223 of the housing 20 (i.e., the cover 22).

[0087] The second support plate 32 is, for example, a disc-shaped support plate. The second support plate 32 may be substantially non-porous (which means that it completely seals the lower end of the filter medium 33 to which it is fixed), or it may be of the porous type, i.e., it also has a central hole centered on the central axis A of the filter medium 33 and a central stem, for example, a substantially cylindrical central stem, which defines and axially extends the central hole and has a corresponding annular (inner or outer) gasket.

[0088] The coupling body protrudes from the surface of the second support plate 32 opposite to the surface fixed to the filter medium 33. In this case, the coupling body is one or more coupling teeth 34 that are eccentric (and equal to each other).

[0089] In the example described, the second support plate 32 includes a total of three coupling teeth 34. For example, these three coupling teeth 34 are equidistant from each other (and are arranged along a hypothetical circumference centered on the central axis A).

[0090] Each coupling tooth 34 includes a stem 340. For example, the stem 340 is bendable substantially radially (with respect to the central axis A). The proximal end of the stem 340 near the second support plate 32 originates from the second support plate 32 (e.g., is integrally formed therewith), and the distal end of the stem 340 away from the second support plate 32 is free.

[0091] In the example shown, the stem 340 has a cross-section (perpendicular to the central axis of the filter medium 30) that extends along a substantially curved longitudinal axis (e.g., in accordance with an arc).

[0092] In the example, the longitudinal axis of the stem 340 in the plane perpendicular to the central axis of the filter medium 30 is substantially arcuate, with its concave surface facing the central axis A of the filter element.

[0093] In particular, the longitudinal axis of the stem 340 is centered on a curvature axis that coincides with the central axis of the filter element 30.

[0094] The stem 340 has a substantially prismatic shape and, in particular, has a first side located proximally relative to the central axis A and a second side located distally relative to the central axis A. The first side is substantially defined by a cylindrical portion centered on the central axis A, and the second side is substantially defined by an additional cylindrical portion centered on the central axis A and having a larger diameter relative to the first side.

[0095] The stem 340 also includes two side surfaces (defining the side surfaces of the stem 340 and circumferentially defining them as well). For example, these side surfaces are parallel to each other and parallel to the central axis A. In the example, the plane of symmetry of these side surfaces is parallel to the central axis A and does not contain the central axis A.

[0096] The circumferential distance between the two sides defines the circumferential (maximum) length of the rod 340.

[0097] At least a portion of the rod 340 of the coupling teeth 34 is adapted to engage with the prismatic seat 214 of the cup-shaped body 21 through a prismatic connection (i.e., with axial translation, the filter element 30 is coaxially inserted into the cup-shaped body 21).

[0098] The joint head 341 originates from the free distal end of the rod 340, and the joint head 341 projects substantially in a cantilever form from the rod 340 in a direction substantially parallel to the second support plate 32. Preferably, the joint head 341 and the rod 340 are integrally formed.

[0099] For example, the joint head 341 extends substantially radially outward from the rod 340 towards the second support plate 32 (i.e., in the opposite direction with respect to the central axis A).

[0100] Advantageously, at least one portion of the joint head 341 of the coupling teeth 34 is adapted to engage with the prismatic seat 214 of the cup-shaped body 21 through a prismatic connection (i.e., with axial translation, the filter element 30 is coaxially inserted into the cup-shaped body 21).

[0101] As will be better described below, the joint head 341 is also, for example, substantially prismatic and substantially trapezoidal in shape. Preferably, the joint head 341 is prismatic and based on a scalene trapezoid.

[0102] In the example described, the joint head 341 includes a first forming surface 3410 and a second forming surface 3411. The first forming surface 3410 faces the second support plate 32 and is substantially parallel thereto (i.e., perpendicular to the central axis A of the filter element 30). The second forming surface 3411 is also, for example, substantially flat and, for example, parallel to the first forming surface 3410 (or inclined as required), where the first forming surface 3410 is located proximal to the second support plate 32 (thereby obtaining the coupling teeth 34) and the second forming surface 3411 is located distal to the second support plate 32.

[0103] The first forming surface 3410 and the second forming surface 3411 define the (larger) base of the joint head 341 in the form of (preferably) a scalene trapezoid, where the smaller base of each scalene trapezoid is located distal to the central axis A of the filter element 30, while the larger base of each scalene trapezoid is located proximal to the central axis A.

[0104] In fact, the joint head 341 includes two trapezoidal bases (perpendicular to the central axis A), and the two trapezoidal bases are connected by at least four outer surfaces (parallel to the central axis A). As will be described in detail, the at least four outer surfaces form four corresponding edges (parallel to the central axis A and perpendicular to the two trapezoidal bases).

[0105] The distance between the second forming surface 3411 and the second support plate 32 is at least equal to or greater than the distance between the upper (free) edge of the arc-shaped wall 212 and the lower flat forming surface 2130 of the window 213.

[0106] The joint 341 has at least a free first edge 3412 located at the distal end relative to the rod 340 (and at the distal end relative to the central axis A, that is, facing outward from the second support plate 32). The free first edge 3412 is adapted to axially connect the first forming surface 3410 and the second forming surface 3411 and is substantially perpendicular to them. The first edge 3412 is located at a distance d1 from the central axis A of the filter element 30. For example, the distance d1 is substantially equal to the distance D1 between the first vertex 2132 and the central axis B of the cup-shaped body 21.

[0107] The joint 341 has a free second edge 3413 located at the distal end (i.e., facing outward from the second support plate 32) relative to the rod 340. The free second edge 3413 is adapted to axially connect the first forming surface 3410 and the second forming surface 3411 and is substantially perpendicular to them. The second edge 3413 is located at a distance d2 from the central axis A of the filter element 30. The distance d2 is different from the distance d1 between the first edge 3412 and the central axis A. For example, the distance d2 is substantially equal to the distance D2 between the second vertex 2133 and the central axis B of the cup-shaped body 21, that is, the distance d2 is greater than the distance d1 between the first edge 3412 and the central axis A of the filter element 30.

[0108] The first edge 3412 and the second edge 3413 are rounded, thereby correspondingly defining a cylindrical portion. The axis of the cylindrical portion is parallel to the central axis A and eccentric relative to the central axis A. For example, the rounding radii of the first edge 3412 and the second edge 3413 are different. In particular, the rounding radius of the first edge 3142 is greater than the rounding radius of the second edge 3413.

[0109] For example, between the first edge 3412 and the second edge 3413, the joint 341 includes a positive forming surface (or flank) 3414 facing the central axis A and located at the distal end relative to the central axis A (see Figure 11 ), and the positive forming surface 3414 is adapted to connect the first edge 3412 and the second edge 3413 and is adapted to radially (outwardly) define the joint 341.

[0110] The positive forming surface 3414 defines the outer end of the joint 341 (located at the distal end relative to the rod 340).

[0111] In the example, the positive forming surface 3414 has a concave portion between the first edge 3412 and the second edge 3413, and the concave surface of the concave portion faces the opposite side relative to the central axis A.

[0112] At the junction of the positive forming surface 3414 and the second forming surface 3411, a third edge 34110 is defined (see Figure 10 and Figure 11 for an enlarged view), for example, the third edge 34110 is rounded, and at the junction of the positive forming surface 3414 and the first forming surface 3410, a fourth edge 34100 is defined (see Figure 10 and Figure 11 for an enlarged view), for example, the fourth edge 34100 is a sharp edge at a right angle.

[0113] The connecting portion 341 has at least a fifth edge 3415 that is proximal relative to the rod 340 (and proximal relative to the central axis A, i.e., facing the second support plate 32 inward) (see Figure 8 and Figure 12 ), and the fifth edge 3415 is adapted to axially connect the first forming surface 3410 and the second forming surface 3411 and is substantially at a right angle to them. The fifth edge 3415 is located at a distance d5 from the central axis A of the filter element 30. For example, the distance d5 is approximately equal to the distance D3 between the first additional vertex 2134 and the central axis B of the cup-shaped body 21.

[0114] The connecting portion 341 also has a sixth (free) edge 3416 that is proximal relative to the rod 340 (proximal relative to the central axis A), i.e., facing the second support plate 32 inward. The sixth edge 3416 is adapted to axially connect the first forming surface 3410 and the second forming surface 3411 and is substantially at a right angle to them. Preferably, the sixth edge 3416 is located at a distance d6 from the central axis A of the filter element 30. The distance d6 is different from or equal to the distance d5 of the fifth edge 3415 from the central axis A. For example, the distance d6 is approximately equal to (or slightly less than) the distance D4 between the second additional vertex 2135 and the central axis B of the cup-shaped body 21.

[0115] The connecting head 341 is circumferentially defined by two opposite sides (lateral sides) 3417, 3418, where the first side 3417 (see Figure 8 ) connects the first edge 3412 and the fifth edge 3415, and the second side 3418 (see Figure 8 ) connects the second edge 3413 and the sixth edge 3416.

[0116] The two sides 3417, 3418 are substantially perpendicular to the surface of the second support plate 32, and the planes in which the two sides 3417, 3418 are located (ideally) intersect at an intersection line a that is substantially parallel and eccentric to the central axis A of the second support plate 32 and is located outside it.

[0117] In fact, the connecting tooth 34 is located between the central axis A and the intersection line a of the side surfaces 3417, 3418.

[0118] In fact, the first side surface 3417 is located proximally relative to the central axis A of the second support plate 32, while the second side surface 3418 is located distally relative to the central axis A.

[0119] For example, the first side surface 3417 of the connector head 341 has a greater inclination (and a greater length) relative to the circumferential (or tangential) direction of the second side surface 3418. The free end of the first side surface 3417 located distally relative to the central axis A is defined by the first edge 3412, and the free end of the second side surface 3418 located distally relative to the central axis A is defined by the second edge 3413.

[0120] Moreover, the connector head 341 includes a side portion 3419, which includes the second side surface 3418, the second edge 3413, and the sixth edge 3416. The side portion 3419 projects cantilever - like in the circumferential direction and beyond the circumferential length of the rod 340, thereby defining an additional formed front surface 34190 located proximally relative to the central axis A (opposite to a part of the formed surface 3414) (see Figure 12 ). The additional formed front surface 34190 faces the central axis A and radially delimits the side portion 3419.

[0121] Preferably, the side portion 3419 is substantially elastically bendable in the radial (and / or axial) direction so as to give the connecting tooth 34 a specific overall (elastic) bendability in the radial (and / or axial) direction.

[0122] The additional formed front surface 34190 defined by the side portion 3419 is adapted to connect the sixth edge 3416 and the concave edge 34191 (see Figure 12 ). The concave edge 34191 connects the side portion 3419 to the rod 340 and is substantially aligned with one of the two edges located distally relative to the central axis A of the rod 340.

[0123] Generally speaking, the connector head 341 is shaped to be axially supported in the prismatic seat 214 of the formed handle 212 with appropriate dimensions. For example, the second formed surface 3411 of the connector head 341 is located proximally relative to the bottom wall 210, and the second side surface 3418 of the connector head 341 is located distally relative to the corresponding window 213, thereby defining an axial prismatic connection therein.

[0124] Moreover, the distance between the first forming surface 3410 and the second forming surface 3411 (i.e., the maximum height of the connecting head 341) is approximately less than (or equal to) the distance between the lower flat forming surface 2130 and the upper flat forming surface 2131 of the corresponding window 213 (i.e., the maximum height of the window 213). In the example, the maximum height of the connecting head 341 is approximately equal to half of the maximum height of the window 213.

[0125] Moreover, the trapezoidal shape of the coupling head 341 (in plan view) is roughly complementary to the trapezoidal shape of the window 213 (in plan view), so that, as better described below, when the coupling head 341 is rotated about the central axis A (coaxial with the central axis B) starting from the prismatic seat 214 in the preferred inlet direction, the window 213 can roughly accommodate the coupling head 341 in a customized manner.

[0126] In view of the above, the operation of the filtration unit 10 is as follows.

[0127] To assemble the filter unit 10, first fully axially (eg, Figure 13 ) is inserted into the cup-shaped body 21 with the shell 20 opened (ie, the cover 22 is removed from the cup-shaped body 21).

[0128] In particular, the size of the inner cavity of the cup-shaped body 21 and the size of the outer length of the filter element 30 are such that once the filter element 30 is inserted into the cup-shaped body 21, the central axis of the filter element 30 is substantially coaxial with the central axis of the cup-shaped body 21. When the filter element 30 is inserted into the cup-shaped body 21, the second support plate 32 faces the bottom wall 210 of the cup-shaped body without a preset preferred orientation until they contact each other.

[0129] In particular, the second forming surface 3411 of the coupling tooth 34 is in contact with the upper edge of the forming handle 212, for example, in contact with a portion greater than its height.

[0130] At this stage, the molded handle 212 defines a first axial end that abuts against the filter element 30 (see Figure 15a ).

[0131] The filter element 30 is driven by rotation about the central axis, for example counterclockwise, until the coupling tooth 34 (i.e., the second shaped surface 3411 thereof) enters axially into the corresponding prismatic seat 214 of the shaped shank 212 by sliding on the shaped shank 212 (see Figure 15b ), thereby achieving the centering of the coupling tooth 34 of the filter element 30 relative to the prismatic seat 214 and the centering of the window 213 of the forming handle 212.

[0132] Thus, in order to assemble the filter element 30 to the cup-shaped body 21, each connecting tooth 34 is axially inserted into the corresponding prismatic seat 214. In this position, each connecting tooth 34, in particular its connecting head 341 (circumferentially and / or at least partially radially), is located next to the corresponding window 213.

[0133] At this time, in the aforementioned preferred direction (i.e., Figure 15c and Figure 15d the counterclockwise direction shown), the filter element 30 is rotated, for example, by a limited angle, and the connecting head 341 engages with the window 213 by snap connection.

[0134] The snap connection is determined by the elastic (radial) bending of the connecting tooth 34, in particular the rod 340 and / or the side portion 3419 (the elastic deformation of which reduces the amount of deformation required for the rod 340).

[0135] Actually, during the rotational connection, the mutual sliding between the positive forming surface 3414 of the connecting head 341 and the vertex 2135 of the window 213 causes the connecting tooth 34 or the rod 340 to bend axially into the second support plate 32 (i.e., towards the central axis A).

[0136] Actually, the positive forming surface 3414 of the connecting head 341 defines the actual profile for the connecting tooth portion 34, and this actual profile is configured to radially deflect and push the rod 340 during the mutual axial rotational connection when there is forced contact between the connecting head 341 and the vertex 2135.

[0137] When the first edge 3412 and / or the second edge 3413 have passed beyond the vertex 2135 and the connecting tooth 34 is substantially radially aligned with the window 213 due to the rotational connection, for the connecting head 341 to engage with the window, the connecting tooth freely springs back to its rest position.

[0138] In particular, in the connection configuration of the connecting tooth 34 in the rest position (see Figure 15d ), the connecting head 341 is substantially axially aligned with the lower flat forming surface 2130 and the upper flat forming surface 2131.

[0139] In addition, the connecting tooth 34 can freely slide axially along the window 213, for example, until the second forming surface 3411 of the connecting head 341 rests on the lower flat forming surface 2130 of the window (or the first forming surface 3410 rests on the upper flat forming surface 2131).

[0140] Actually, the filter element 30 moves, for example, under its own gravity to a position close to the bottom wall 210, where the second forming surface 3411 of the connecting head 341 rests on the lower flat forming surface 2130 of the window 213.

[0141] With the filter element 30 in this stable connection position, the housing 20 can be closed by screwing the corresponding cover 22 into the cup-shaped body 21. Thereafter, the cover 22 is closed on the cup-shaped body 21, preventing any axial (and rotational) movement of the filter element 30.

[0142] On the other hand, if the cup-shaped body 21 connected to the filter element 30 is arranged (in a vehicle) with its concave surface facing downwards, the filter element will remain in the vertical direction due to the interaction between the first forming surface 3410 of the connecting teeth 34 and the upper flat forming surface 2131 of the window 213.

[0143] To continue removing the filter element 30 from the housing 20, it is sufficient to operate in a direction opposite to the direction for assembling the filter unit 10 described above.

[0144] Therefore, the present invention as conceived allows for many modifications and variations, all of which are included within the scope of the inventive concept.

[0145] For example, although a hybrid (radial) snap and bayonet connection is described, which provides a rotational translation of the filter element 30 relative to the cup-shaped body 21, it is not excluded that the mutual connection can be, for example, of the axial connection type, where the connecting head 341 is provided to be substantially axially bendable and substantially axially insertable into the window 213.

[0146] Furthermore, it is not excluded that a formed handle with a window is provided on the support plate of the filter element 30 in the same way, and the connecting teeth can be provided on the bottom wall of the cup-shaped body 21.

[0147] Moreover, similar to the above, it can be arranged that the formed handle 212 (or the connecting teeth 34) with the window 213 can be provided in the cover 22 instead of in the cup-shaped body 21, or in an intermediate support element, which is fixed or connected to one of the cover 22 and the cup-shaped body 21 that make up the housing 20.

[0148] In addition, all details can be replaced by other technically equivalent elements.

[0149] In fact, therefore, any material and any possible shape and size can be used as needed without departing from the scope of protection of the following claims.

Claims

1. A filter element (30), the filter element (30) comprising a tubular filter medium (33) and a support plate (32) fixed to one end of the filter medium (33), the filter medium (33) having a central axis (A), wherein the support plate (32) comprises coupling teeth (34), the coupling teeth (34) having a stem (340) and a coupling head (341), the stem (340) protruding from a surface of the support plate (32) opposite to the filter medium (33), the coupling head (341) protruding radially outwards relative to the central axis (A) in a cantilever form from the stem (340), wherein the coupling head (341) comprises at least two free edges (3412, 3413) that are opposite and located distally relative to the central axis (A), the two edges (3412, 3413) being at different distances from the central axis (A) of the filter medium, and the coupling head (341) comprises sides (3419) that protrude in a circumferential cantilever form and extend beyond the circumferential length of the stem (340).

2. The filter element (30) according to claim 1, wherein, the two edges (3412, 3413) of the coupling head (341) are rounded, thereby correspondingly defining a cylindrical portion, the axis of the cylindrical portion being parallel to the central axis (A) and eccentric relative to the central axis (A).

3. The filter element (30) according to claim 1 or 2, wherein, the coupling head (341) of the coupling teeth (34) comprises two opposite sides (3417, 3418), the two opposite sides (3417, 3418) circumferentially defining the coupling head (341), wherein the planes in which the two opposite sides (3417, 3418) are located intersect at an intersection line (a), the intersection line (a) being parallel and eccentric relative to the central axis (A) of the filter medium (33), wherein the coupling teeth (34) are between the central axis (A) and the intersection line (a).

4. The filter element (30) according to claim 1, wherein, the coupling head (341) of the coupling teeth (34) comprises a first forming surface (3410), the first forming surface (3410) being flat and perpendicular to the central axis (A) of the filter medium (33) and located proximally relative to the support plate (32), the first forming surface (3410) being defined by at least four vertices, wherein two of the vertices are located distally relative to the central axis (A) and two of the vertices are located proximally relative to the central axis (A), wherein the first forming surface (3410) and the two edges (3412, 3413) located distally relative to the central axis (A) meet at two vertices located distally relative to the central axis (A).

5. The filter element (30) according to claim 4, wherein, The coupling head (341) includes a second forming surface (3411) that is located distally relative to the support plate (32) and is also perpendicular to the central axis (A).

6. The filter element (30) according to claim 5, wherein, the coupling head (341) of the coupling teeth (34) includes a positive forming surface (3414) that is located distally relative to the central axis (A), the positive forming surface (3414) radially defines the first and second forming surfaces (3410, 3411), and is adapted to connect the two edges (3412, 3413) that are located distally relative to the central axis (A).

7. The filter element (30) according to claim 6, wherein, the positive forming surface (3414) has a concave portion that is between the two edges (3412, 3413) that are located distally relative to the central axis (A), and is adapted to connect the two edges (3412, 3413) that are located distally relative to the central axis (A), and has a concave surface facing away from the central axis (A).

8. The filter element (30) according to claim 1, wherein, the rod (340) of the coupling teeth (34) is elastically bendable in the radial direction.

9. The filter element (30) according to claim 1, wherein, the coupling head (341) includes two additional edges (3415, 3416) that are located proximally relative to the central axis (A), and the two additional edges (3415, 3416) are also at different distances from the central axis (A) of the filter element.

10. The filter element (30) according to claim 9, wherein, the side portion (3419) includes one of the two edges (3412, 3413) that is located distally relative to the central axis (A) of the coupling head (341), the nearest additional edge (3416) of the two additional edges (3415, 3416) that is located proximally relative to the central axis (A), and a side surface (3418) that circumferentially defines the side portion (3419) and is between the one edge (3413) and the additional edge (3416), wherein the side portion (3419) includes an additional forming front surface (34190) that is located proximally relative to the central axis (A) and radially defines the side portion (3419), wherein the additional forming front surface (34190) is adapted to connect the additional edge (3416) included in the side portion (3419) and the concave edge (34191) of the side portion (3419), and the concave edge (34191) is aligned with the rod (340) and connects the side portion (3419) to the rod (340).

11. The filter element (30) according to claim 10, wherein, The side portion (3419) of the coupling head (341) is elastically bendable at least radially.

12. The filter element (30) according to claim 6, wherein, a third edge (34110) at which the second forming surface (3411) meets the positive forming surface (3414) located distally relative to the central axis (A) is rounded. The third edge radially defines the first and second forming surfaces (3410, 3411) and connects the two edges (3412, 3413) located distally relative to the central axis (A).

13. The filter element (30) according to claim 6, wherein, a fourth edge (34100) at which the first forming surface (3410) meets the positive forming surface (3414) is a sharp edge at a right angle.

14. A support body (21) of a filter element (30), wherein, it includes a disc-shaped wall (210) and a forming handle (212). The disc-shaped wall (210) has a central axis (B). The forming handle (212) protrudes from the surface of the disc-shaped wall (210) and defines a coupling window (213). The coupling window (213) is axially defined by two flat forming surfaces (2130, 2131) and circumferentially defined by two side walls (2136, 2137). The two flat forming surfaces (2130, 2131) are parallel to each other and perpendicular to the central axis (B). The two side walls (2136, 2137) are perpendicular to the flat forming surfaces (2130, 2131), and the planes in which the two side walls (2136, 2137) are located intersect at an intersection line (b). The intersection line (b) is parallel and eccentric relative to the central axis (B) and is located outside it; the forming handle (212) includes a prismatic seat (214). The prismatic seat (214) is open at its top and is blocked by the disc-shaped wall (210) of the support body (21) below. The axis of the prismatic seat (214) is parallel to the central axis (B). The prismatic seat (214) is circumferentially aligned with and adjacent to the corresponding window (213). The prismatic seat (214) is radially defined by a wall (2142) located distally relative to the central axis (B) and a wall portion (2143) located proximally relative to the central axis (B). The wall portion (2143) is defined by a protrusion (2141) protruding from the disc-shaped wall (210). The protrusion (2141) is located proximally relative to the central axis (B) of the opposite closing wall (2140) in the circumferential direction towards the corresponding window (213).

15. The support body (21) according to claim 14, wherein, the forming handle (212) has a varying height relative to the disc-shaped wall (210) along its circumference, wherein the forming handle (212) has a minimum height relative to the disc-shaped wall (210) at the circumferential portion provided with the prismatic seat (214).

16. A filtering unit (10), characterized in that, the filtering unit (10) comprises a support body (21) according to any one of claims 14 to 15 and a filter element (30) according to any one of claims 1 to 13, wherein the coupling teeth (34) of the filter element (30) are adapted to releasably couple to the window (213) of the support body (21).

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