DISK FILTER AND METHOD FOR THE MANUFACTURE THEREOF

Abstract

A filter, including a plurality of annularly closed disks having a through-opening. The disks include at least one contact area projecting from a lateral surface for a contact with an adjoining disk, and radial flow-through areas adjoining the contact area, and the disks being situated as a disk stack.

Claims

1-28. (canceled)

29. A filter, comprising: a plurality of annularly closed disks having a through-opening, the disks including at least one contact area projecting from a lateral surface for a contact with an adjoining one of the disks, and radial flow-through areas adjoining the contact area, the disks being situated as a disk stack, the radial flow-through areas being formed by a distance between two adjoining disks, and the radial flow-through areas providing a filter action.

30. The filter as recited in claim 29, wherein a closed terminating disk is situated on one end of the disk stack.

31. The filter as recited in claim 29, wherein the disks are joined to one another on a joining area.

32. The filter as recited in claim 31, wherein the joining area of the disks extends in the axial direction of the disk stack.

33. The filter as recited in claim 32, wherein the disks are joined to one another with the aid of one of: (i) a welded joint, (ii) an adhesive joint, (iii) a soldered joint, (iv) a press-fit joint, or (v) a sleeve having a flared joint.

34. The filter as recited in claim 29, further comprising: a preloading element which preloads the disk stack.

35. The filter as recited in claim 34, wherein the preloading element is one of a spring element or a preloading sleeve.

36. The filter as recited in claim 29, wherein a gimbal mount is provided on an axial end of the disk stack.

37. The filter as recited in claim 29, further comprising: a sealing element which is situated on at least one axial end of the disk stack.

38. The filter as recited in claim 29, further comprising: a press-fit element which is configured to fix the filter in a borehole.

39. The filter as recited in claim 29, wherein each of the disks includes at least one alignment area.

40. The filter as recited in claim 39, wherein, (i) the alignment area is at least one of an inwardly projecting nose and an outwardly projecting nose, or (ii) the alignment area is a recess provided on at least one of an inner circumference and the outer circumference.

41. The filter as recited in claim 29, wherein each of the disks includes a first projecting contact area on a disk surface, and a second projecting area on a disk undersurface.

42. The filter as recited in claim 29, wherein each of the disks includes inflow grooves and outflow grooves on at least one of a disk surface and a disk undersurface.

43. The filter as recited in claim 29, wherein the disks are one of: (i) stamped parts, (ii) EMC parts, (iii) coated parts in which the contact areas are created with the aid of coating, or (iv) electropolished parts in which the radial flow-through areas are created with the aid of electropolishing.

44. The filter as recited in claim 41, wherein a height of the projecting contact areas is in a range of 1/10 to 1/20 of a thickness of the disk.

45. The filter as recited in claim 41, wherein the projecting contact areas of the disks are situated on a line, which is in parallel to a center axis of the disk stack.

46. The filter as recited in claim 29, wherein each of the disks includes at least three inwardly and/or outwardly projecting alignment areas for a centering of the disk stack in a borehole.

47. The filter as recited in claim 29, wherein the filter is a fuel filter.

48. An assembly, including a filter, the filter comprising a plurality of annularly closed disks having a through-opening, the disks including at least one contact area projecting from a lateral surface for a contact with an adjoining one of the disks, and radial flow-through areas adjoining the contact area, the disks being situated as a disk stack, the radial flow-through areas being formed by a distance between two adjoining disks, and the radial flow-through areas providing a filter action.

49. The assembly as recited in claim 48, wherein the assembly is a fuel-conducting assembly.

50. The assembly as recited in claim 49, wherein the assembly is a valve or a rail or a fuel pump.

51. A method for manufacturing a filter, comprising: providing a plurality of annularly closed disks including at least one projecting contact area and at least one radial flow-through area; and stacking the plurality of disks to form a disk stack to provide a filter through which flow is possible in the radial direction of the disk stack.

52. The method as recited in claim 51, further comprising: axially preloading the disk stack.

53. The method as recited in claim 51, further comprising: joining the disks of the disk stack to one another on at least one joining area.

54. The method as recited in claim 53, wherein the joining of the disks takes place with the aid of at least one of: (i) welding on an outer circumference of the disk stack, (ii) welding on an inner circumference of the disk stack, (iii) gluing, (iv) soldering, (v) press-fit joining, and (vi) flare joining with the aid of a sleeve.

55. The method as recited in claim 51, wherein the radial flow-through areas between projecting contact areas are created by one of: (i) pressing, (ii) electrochemical machining, or (iii) electropolishing.

56. The method as recited in claim 51, wherein a closed terminating disk is situated on an axial end of the filter on a disk stack formed by the disks.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Preferred exemplary embodiments of the present invention are described hereafter in greater detail with reference to the figures. Identical or functionally equivalent parts are denoted by the same reference numerals.

[0030] FIG. 1 shows a schematic sectional view of a filter according to the present invention according to a first exemplary embodiment of the present invention.

[0031] FIG. 2 shows a schematic, enlarged view of the filter from FIG. 1.

[0032] FIG. 3 shows a schematic top view onto a disk surface of a disk of the filter from FIG. 1.

[0033] FIG. 4 shows an enlarged sectional view of a disk of the filter from FIG. 1.

[0034] FIG. 5 shows a schematic sectional view of an installation state of the filter from FIG. 1.

[0035] FIG. 6 shows a schematic, perspective view of a spring element for preloading the filter.

[0036] FIG. 7 shows a perspective view of the filter from FIG. 1.

[0037] FIG. 8 shows a schematic sectional view of a filter according to a second exemplary embodiment of the present invention in the installed state.

[0038] FIG. 9 shows a schematic top view onto a disk of a filter according to a third exemplary embodiment of the present invention.

[0039] FIG. 10 shows a schematic sectional view of the disk from FIG. 9.

[0040] FIG. 11 shows a schematic sectional view of a filter according to a fourth exemplary embodiment in the installed state.

[0041] FIG. 12 shows a schematic sectional view of a filter according to a fifth exemplary embodiment of the present invention.

[0042] FIG. 13 shows a schematic view of a disk surface of a filter according to a sixth exemplary embodiment.

[0043] FIG. 14 shows a schematic sectional view of a filter in the installed state according to a seventh exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0044] A filter 1 according to a first preferred exemplary embodiment of the present invention is described in greater detail hereafter with reference to FIGS. 1 through 7.

[0045] As is in particular apparent from the sectional view of FIG. 1, filter 1 includes a plurality of disks 2 which are situated on top of one another and form a disk stack. This is apparent in a perspective view from FIG. 7.

[0046] As is shown in FIG. 3, disks 2 are annularly closed disks and have a through-opening 22.

[0047] As is apparent from FIGS. 3 and 4, the disks have a disk surface 23 and a disk undersurface 24. Multiple projecting contact areas 20 are provided on disk surface 23. As is apparent from the sectional view of FIG. 4, a height H of the contact areas relative to a radial flow-through area of disk 2 is in a range of 10 m.

[0048] In this exemplary embodiment, six contact areas 20 are provided on disk surface 23. Correspondingly six radial flow-through areas 21 are also provided. As is apparent in particular from FIG. 4, no projecting areas are provided on disk undersurface 24, so that lateral undersurface 24 is planar.

[0049] As explained above, disks 2 are situated to form a disk stack, three alignment areas 25 being provided on each disk for alignment. Alignment areas 25 are formed on the outer circumference of each disk 2 and are provided as radially outwardly projecting areas. A transition to the disk circumference is provided as a continuous transition. On joining areas 26, which in this exemplary embodiment are weld seams, disks 2 are furthermore joined to one another in axial direction X-X on the outer circumference of the disk stack.

[0050] As becomes coherent in particular from FIGS. 2 and 4, a respective gap 3 is provided between adjoining disks 2 due to the stacking of disks 2 to form a disk stack. Gap 3 has a respective width corresponding to height H of contact area 20 since disk undersurface 24 of disks 2 is planar.

[0051] The filter thus provided may be manufactured with the aid of different methods. For example, in a first step, disks 2 may be stamped from a sheet metal material and subsequently radial flow-through areas 21 may be generated, for example with the aid of pressing or electrochemical machining (EMC) or electropolishing. As an alternative or in addition, it would also be conceivable that contact areas 20 are generated by partial coating of the disk surface. In this way, it is possible to create very small heights H in the range up to 5 m, so that a very good filter performance is achieved by the filter according to the present invention.

[0052] FIG. 5 shows the installation of filter 1 according to the present invention in a cylinder component 6 of an injector for fuel. A borehole diameter of cylinder component 6 is larger than a maximum outside diameter of filter 1. Filter 1 is held in cylinder component 6 under preload with the aid of a spring element 5 (see FIG. 6). Reference numeral 7 denotes a sealing ring, which seals the outer circumference of filter 1 with respect to cylinder component 6.

[0053] Filter 1 is held in cylinder component 6 under preload with the aid of spring element 5. Spring element 5 is shown in detail in FIG. 6. Spring element 5 includes three inwardly directed spring noses 50, which generate the preload. Spring element 5 is pressed with a peripheral edge 51 into the borehole in cylinder component 6. In this way, a sufficient preload may be exerted on filter 1.

[0054] As shown in FIG. 5, fuel now flows corresponding to arrow A through spring element 5 toward the outer circumference of filter 1, which is closed with the aid of a closed terminating disk 4 against which spring element 5 rests. The fuel thus flows from the outer circumference of filter 1 through gap 3 between disks 2 to the inner circumference and from there, corresponding to arrow B, to the injector.

[0055] Due to the small gap height of gap 3, it is thus possible with the aid of filter 1 according to the present invention to filter appropriate particles from the fuel even in the case of biofuels. Furthermore, partial lifts of the valve up to approximately 20 m with a full lift of approximately 35 m may be carried out, without clogging occurring as a result of particles on the valve seat.

[0056] It shall furthermore be noted that, as becomes apparent from FIG. 5, filter 1 does not necessarily have to be welded together with the aid of joining areas 26, but that disks 2 could also be loosely stacked as a result of the preload with the aid of filter element 5 in cylinder component 6 and then be pressed against one another by fixation of spring element 5. This, however, has assembly-related disadvantages, so that a filter 1 present as an installation part, which is joined by weld seams or the like, is easier to install.

[0057] FIG. 8 shows a filter 1 according to a second exemplary embodiment of the present invention. Filter 2 of the second exemplary embodiment is formed completely as a hollow cylinder. As the installation situation in an injector in FIG. 8 shows, filter 1 furthermore includes a first sealing element 7 and a second sealing element 70. First sealing element 7 is situated on a first end of filter 1, and second sealing element 70 on a second end. The fuel is supplied corresponding to arrow A to the outer circumference of filter 1, then flows through radial flow-through areas 21 between disks 2 to the inner area of filter 1 and from there, corresponding to arrow B, to a tip of a valve needle 60 (not shown in detail). Filter 1 thus does not include a closed terminating disk, but is situated between two components of a fuel-conducting element with the aid of two sealing elements.

[0058] FIGS. 9 and 10 show a disk 2 of a filter according to a third exemplary embodiment of the present invention. As is apparent in particular from FIG. 10, disk 2 of the filter of the third exemplary embodiment includes first projecting contact areas 20 on a disk surface 23, and second projecting contact areas 27 on a disk undersurface 24. In the disk stack, respective projecting contact areas 20 or 27 of the adjoining disk then rest against one another, so that the gaps between the disks are formed. Alternatively, the disks may also be situated in such a way that a respective contact area rests against a radial flow-through area 21, so that the contact areas are each offset in the circumferential direction of disks 2.

[0059] FIG. 11 shows a filter 1 according to a fourth exemplary embodiment of the present invention. Filter 1 corresponds to that of the first exemplary embodiment, closed terminating disk 4 being situated on a first end of filter 1, and a gimbal mount 8 being provided on a second end of filter 1. The gimbal mount is provided by a conical area 80 of a termination component 81. Prior to the final fixation of filter 1, it will be inserted into cylinder component 6 and aligned coaxially to center axis X-X with the aid of gimbal mount 8, e.g., also when manufacturing-related component tolerances occur, and then fixed with the aid of spring element 5.

[0060] FIG. 12 shows a filter 1 according to a fifth exemplary embodiment of the present invention. Filter 1 of fifth exemplary embodiment additionally includes a sleeve 9, which is provided as a joining element for joining the individual disks 2 stacked in the disk stack. Sleeve 9 includes a bent area 90 on a first end of the filter against which last disk 2 of the filter is supported. Furthermore, sleeve 9 includes a crimp area 91, which is crimped on the sleeve after the disk stack has been positioned and aligned in order to exert an appropriate preload on disks 2. As is furthermore apparent from FIG. 12, disks 2 of this exemplary embodiment are not all designed the same. Disks 2 of the filter include first disks, as shown in FIG. 10, having a first and a second projecting contact area 20, 27 and, adjoining thereon, a flat disk 2 having no projecting areas. Disks 2, 2 are alternately arranged so that the distance between disks 2, 2 is the same. This creates the small gaps 3 between neighboring disks, which are responsible for the filter action.

[0061] FIG. 13 shows a filter 1 according to a sixth exemplary embodiment of the present invention. Three inflow grooves 11 and three outflow grooves 12 are formed in disk surface 23. The unfiltered fuel is supplied to inflow grooves 11 and is then conducted via radial flow-through areas 21 to outflow grooves 12, and from there into the interior of filter 1 (arrows B).

[0062] FIG. 14 shows a filter 1 according to a seventh exemplary embodiment of the present invention. Filter 1 of the seventh exemplary embodiment includes a press-fit ring 10, which is pressed into a borehole of a valve component 6 with the aid of a press-fit joint 13, on a free end of filter 1. Alternatively, welding, crimping, screening or soldering is also possible. As indicated by arrow A, fuel flows into the interior of filter 1 and via radial flow-through areas 21 radially from the inside to the outside. In this exemplary embodiment, the flow direction is thus opposite that of the preceding exemplary embodiments since the flow direction on filter 1 is provided to be from the inside to the outside. As indicated by arrow B, the fuel is then supplied to injection openings or the like. Press-fit ring 10 is preferably fixed together with disks 2 with the aid of the weld seam extending in the axial direction.

[0063] With regard to all described exemplary embodiments, the flow direction through the filter, i.e., from the outside to the inside or from the inside to the outside, may be selected corresponding to the particular conditions. The number of disks forming filter 1 is also provided as a function of the filter performance to be delivered. On the disks, alignment areas 25 may be formed on the inner circumference and/or on the outer circumference. Alignment areas 25 may also be used to center the filter in a borehole. The disks are preferably provided from a metal material and may in particular be manufactured by stamping and pressing. In this way, the filter according to the present invention may in particular be used for applications, e.g., E100, which include pure biofuel or large admixed amounts of biofuels. The production methods for manufacturing the disks allow smaller tolerances than were previously possible. In the case of injectors, it is furthermore possible that also smaller needle lifts, up to approximately 20 m, may be carried out since the filters according to the present invention have a smaller gap size, in particular in the range of 10 m. This does not result in a problem with only smaller needle lifts which are carried out in the partial load operation of an internal combustion engine, for example.