Abstract
A device for separating oil droplets and/or oil mist from blow-by gases of an internal combustion engine having a valve for controlling the gas flow through the oil separator is disclosed. The valve has at least one valve body with at least one gas through-opening and also a valve seal for closing this at least one gas through-opening.
Claims
1-19 (canceled)
20. A device for separating oil droplets and/or oil mist from blow-by gases of an internal combustion engine having a valve for controlling the gas flow from a pressure side to a suction side of the oil separator, the valve having a valve body with at least one gas through-opening from the pressure side to the suction side of the valve and also a valve seal for suction-side closure of at least one of the gas through-openings of the valve body, the valve seal having at least one spring element which is configured such that at least one of the gas through-openings can be closed by the spring element, wherein at least one of the spring elements, via which at least one of the gas through-openings can be closed, is coated with an elastic material on the surface which is orientated towards the gas through-opening in the region of at least one of the gas through-opening.
21. The device according to claim 20, wherein the valve body has at least one baseplate in which at least one gas through-opening is disposed, at least one of the gas through-openings being delimited in a radial direction by respectively a wall which protrudes in the direction of the spring element beyond the baseplate.
22. The device according to claim 21, wherein the case of at least one gas through-opening, a cover region of the wall which is directly adjacent to the spring element and extends from the open end over 1 mm, has a wall thickness of 1 mm.
23. The device according to claim 22, wherein the case of at least one gas through-opening, a cover region of the wall which is directly adjacent to the spring element and extends from the open end over 0.5 mm, has a wall thickness of 0.5 mm.
24. The device according to claim 23, wherein the case of at least one gas through-opening, a cover region of the wall which is directly adjacent to the spring element and extends from the open end over 0.1 mm, has a wall thickness of 0.2 mm.
25. The device according to claim 24, wherein the wall thickness of the wall in the cover region is configured, at least in regions along the circumferential edge of the through-opening, such that, if a spring element which is coated with the elastic material closes the gas through-opening, the ratio between, on the one hand, a) the cross-sectional area of the gas through-opening at the open end of the wall; or b) the area of the elastic material, which is surrounded by the contact surface of the wall with the elastic material; and, on the other hand, the contact area between the wall and the elastic material is 50.
26. The device according to claim 25, wherein the wall in the cover region, at least in regions along the circumferential edge of the through-opening, has an edge having a radius of curvature of 0.1 mm.
27. The device according to claim 25, wherein the wall in the cover region, at least in regions along the circumferential edge of the through-opening, has an edge for at least one gas through-opening, at which the inner and outer surface of the wall converge at an angle of 15.
28. The device according to claim 20, wherein the material of the coating of the spring element consists of an elastomer, comprising polyacrylate rubber (ACM), ethylene acrylate rubber (AEM), fluorosilicone rubber (FVMQ), fluorinated rubber (FKM), silicone rubber (VMQ), epichlorohydrin rubber (ECO), perfluorinated rubber (FFKM), nitrile-butadiene rubber (NBR), hydrated nitrile-butadiene rubber (HNBR), chloroprene rubber (CR), thermoplastic elastomers (TPE), and also blends and/or mixtures of these materials.
29. The device according to claim 20, wherein the material of the coating of the spring element is, at least in regions, a closed-pore material.
30. The device according to claim 20, wherein the thickness of the coating is from 0.35 to 0.5 mm.
31. The device according to claim 20, wherein the valve body is comprised of a thermoplastic plastic material, including a polyamide, and polyamide 6.6.
32. The device according to claim 20, wherein at least one of the spring elements is comprised of spring steel.
33. The device according to claim 32, wherein one, or several or all of the spring elements has a sheet metal thickness of 0.1 to 0.2 mm.
34. The device according to claim 20, wherein two or more spring elements are provided.
35. The device according to claim 34, wherein the coatings are made of respectively different materials and/or with different material thicknesses and are applied on different spring elements.
36. The device according to claim 20, wherein one, several or all of the spring elements are configured as spring tongue.
37. The device according to clam 20, wherein at least two gas through-openings, which are covered by different spring elements, have different cross-sections of their inlets and/or outlets and/or centrally between their inlets and outlets, including relative to the cross-sectional area and/or cross-sectional shape.
38. The device according to claim 20, wherein, in at least one of the gas through-openings, a conducting geometry is disposed, which sets the through-flowing gases in a rotation about the axial direction of the gas through-opening.
Description
[0045] In the following, some examples of a device according to the invention are described with reference to Figures. Various elements which are essential to the invention or also develop advantageously within the scope of these examples are thereby mentioned, also some of these elements as such being able to be used for developing the inventionalso taken out of the context of the respective example and further features of the respective example. Furthermore, the same or similar reference numbers are used in the Figures for the same or similar elements and explanation thereof can therefore be partly omitted.
[0046] There are shown
[0047] FIG. 1 a device according to the state of the art;
[0048] FIGS. 2 to 8 devices according to the invention;
[0049] FIG. 9 test results for the separation performance of various oil separators; and
[0050] FIGS. 10 to 12 further devices according to the invention and spring elements of devices according to the invention.
[0051] FIG. 1 shows a device for separating oil mist and/or oil droplets from blow-by gases of an internal combustion engine. This device 1 has a valve 2. The valve 2, for its part, has two baseplates 5a and 5b which form the valve body 5, the baseplate 5a being disposed on the pressure side (pressure side 3) and the baseplate 5b, on the suction side (suction side 4). Gas through-openings 10 extend through these baseplates 5a and 5b, only one gas through-opening of which is provided in FIG. 1, by way of example, with a reference number. The gas through-openings 10 have radial walls 11 and 12, the wall 11a, 11b, 12a and 12b of which are provided, by way of example, with reference numbers. The walls 11a and 11b are thereby disposed on the baseplate 5b, on the suction side, whilst the walls 12a and 12b are disposed on the baseplate 5a, on the pressure side. In particular, the walls can be configured also in one piece with the respective associated baseplate. Retaining arms 26a and 26b are disposed at fixing regions 25a and 25b of the baseplate 5b, which retaining arms respectively retain a spring element 20a or 20b configured as spring tongue 21a or 21b. These spring tongues 21a and 21b are consequently mounted elastically and can move between two states in which the gas through-openings 10 are unclosed or closed. The unclosed/opened state is represented for the spring tongue 21a, whilst the closed state is represented for the spring tongue 21b.
[0052] In FIG. 2A, an embodiment according to the present invention is represented in side view, which has however, in contrast to FIG. 1, merely a single baseplate 5 which includes gas through-openings with wall 11a and 11b. This device 1 from FIG. 2A can however readily be supplemented by a corresponding baseplate 5a from FIG. 1 on the pressure side.
[0053] This device 1, relative to the device in FIG. 1, is developed according to the invention by, as illustrated in FIG. 2A, the spring elements 20a and 20b configured in turn as spring tongue 21a and 21b having respectively a coating 23a and 23b made of an elastomeric material 33a, 33b which is disposed respectively on that surface of the spring tongue which is orientated towards the gas through-openings 10. In the present embodiment, the coatings 23a, 23b are partial coatings.
[0054] FIG. 2B shows a plan view on the baseplate 5 of the device from FIG. 2A, which forms the valve body at the same time. The spring tongues 21a and 21b are retained respectively by lateral retaining arms 26a, 26a or 26b, 26b at fixing regions 25a or 25b. In particular from FIG. 2A, it becomes clear that the retaining arms 26a, 26a, 26b and 26b respectively have two bent places 30a, 31a or 30a, 31a or 30b, 31b or 30b, 31b so that the spring elements 20a, 20b extend respectively essentially parallel to the baseplate 5 and maintain this orientation even when moving away from and approaching the baseplate 5. FIG. 2C shows a plan view on the baseplate 5 from the suction side 4. To each of the spring tongues 21a and 21b from FIG. 2B, now not illustrated here, a group of gas through-openings 10a, 10a, 10a, 10a or 10b, 10b, 10b, 10b is assigned respectively. The gas through-openings, mentioned subsequently only for the group assigned to the spring tongue 21a, has a wall 11a which surrounds, in one piece, all of the gas through-openings 10a, 10a, 10a, 10a. According to the invention, each of the gas through-openings 10a to 10a has a cover region 13a to 13a which protrudes in particular from the wall 11a, however is part of the wall 11a at the same time. In these cover regions 13a to 13a, the spring tongue 21a comes in contact with the wall 11a during closure of the gas through-openings 10a to 10a.
[0055] Similarly, this applies for the gas through-openings 10b to 10 and the spring tongue 21b. The gas through-openings 10b to 10b are furthermore provided with conducting geometries which extend helically in the form of a helix in axial direction of the through-openings 10b to 10b and set the blow-by gas in a rotational movement during throughflow of the blow-by gas through the gas through-openings 10b to 10b. As a result, the separation degree of the respective gas through-opening 10b to 10b is improved.
[0056] FIG. 3 shows an example of a further device 1 according to the invention. In contrast to the device according to FIG. 2, here both spring tongues 21a and 21b are provided with coatings of different thicknesses, namely with 0.3 mm or 0.6 mm FKM.
[0057] Furthermore, the gas through-openings or walls 11a, 11b thereof are provided, according to the invention, with cover regions 13a, 13b in which the wall for each individual gas through-opening has a thickness in the direction of its end which tapers conically. As a result, a narrow contact surface is produced as cover region 13a, 13b between the respective coating 23a or 23b, on the surfaces 22a and 22b, orientated towards the gas through-openings, of the spring tongues 21a or 21b with the walls 11a, 11b. This becomes clear in particular from the side view of FIG. 3A.
[0058] In the case of the device 1 according to FIG. 3, furthermore an additional baseplate 5a is provided, as was illustrated already in FIG. 1.
[0059] FIG. 3B now shows a plan view on the baseplate 5b, the spring tongues and also their fixing regions and retaining arms being omitted in the illustration. In contrast to the walls 11a and 11b in FIG. 2, the walls 11a and 11b in FIG. 3 are now configured such that cover regions 13a to 13a or 13b to 13b are raised from this wall in the direction of the spring tongues, in which cover regions the thickness of the wall tapers in the direction of the spring tongue.
[0060] FIG. 4 shows a further device 1 according to the invention in which however merely one single group of gas through-openings is provided, in side view. FIG. 4A and FIG. 4B thereby show the opened state in FIG. 4A and the closed state in FIG. 4B.
[0061] By means of the sharp edge of the wall 11 in the cover region 13, a narrow precise gap between the coating 23 and the suction-side end of the wall 11 is produced, as illustrated in FIG. 4A. This precise gap leads to an improved oil separation during passage of the blow-by gases through the gas through-opening and through the gap between the wall 11 and the coating 23. The coating 23 consists here of FVMQ with a layer thickness of 0.4 mm and a hardness of 59 Shore A, in fact no gas flow being able to be effected through this closed-pore material 33 of the coating 23 but nevertheless good separation of the oil on the surface being effected.
[0062] In FIG. 4B, the closed state is illustrated in which the suction-side edge of the wall 11 is closed about each of the gas through-openings by the coating 23. The edge of the wall 11 is thereby pressed into the elastomeric coating 23 so that a further improved closure of the gas through-openings is effected.
[0063] FIG. 5 shows a further embodiment of the device 1 according to the invention in plan view. In the case of this device 1, in total four groups of gas through-openings 10a to 10a, 10b to 10b, 10c to 10c, 10d to 10d are provided (merely a part of the gas through-openings has been provided with reference numbers). All of the spring elements, not visible here, for the respective groups of gas through-openings have a common fixing region 25. In the case of the illustrated plan view of FIG. 5A, the spring elements are not illustrated in order to show the other construction situated below the spring elements.
[0064] The device 1 has furthermore walls 40a, 40a or 40b, 40b or 40c, 40c or 40d, 40d which surround the gas through-openings and lead to a further improved separation of oil mist and oil droplets.
[0065] FIG. 5B shows a cross-section along the line A-A in FIG. 5A through two gas through-openings 10b, 10b. This cross-section is rotated to the right by 90, compared with the side views of FIGS. 2A, 3A, 4A and 4B, shown previously. The gas through-openings 10b, 10b are thereby configured essentially mirror-symmetrically relative to each other. The walls 11 of the gas through-openings 10b, 10b thereby protrude from the baseplate 5. In axial direction through the baseplate 5 and the walls 11, the cross-section through the gas through-opening 10b, 10b has steps 16, 16 so that the cross-section of the gas through-opening is smaller in the region of the wall 11 than in the region of the baseplate 5. In the direction of the suction side 4, the wall tapers initially in the form of steps 17 and thereafter in a conical shape at its suction-side end, tapering between the outer surface in a chamfered region 18 and the inner surface of the wall 11. The angle between the outer surface in the region 18 and the inner surface is thereby /2, in the present case of FIG. 5B, 30. The angle is thereby determined however not along the total chamfered region but merely between the left end of the chamfered region and the broken line. As a result of the precise edge between the outer surface and the inner surface of the wall 11 on its suction-side end, a further improved oil separation for throughflowing gases is produced in particular by the interaction with the coating of the spring element.
[0066] FIGS. 6 to 8 show further cross-sections through walls 11 of gas through-openings 10 according to the invention, only one gas through-opening being illustrated respectively here, differently from FIG. 5B.
[0067] In FIG. 6, the end region on the suction side 4 of the wall 11 tapers and has a radius of curvature 19 at the sharp end. The radius of curvature 19, in the present example, is approx. 0.3 mm.
[0068] In FIG. 7, the wall 11 is chamfered/bevelled from both sides so that it tapers to a suction-side, sharp end which, viewed microscopically, therefore likewise has a very small radius of curvature of approx. 0.15 mm.
[0069] In FIG. 8, the wall 11 on its inside orientated towards the gas through-opening 10 is chamfered, widening conically in the cover region 13. Also on the outside, a short chamfer is provided which changes via a radius 19 into the chamfer 18 of the outer surface of the wall 11.
[0070] All these embodiments lead to an improved separation of oil mist and oil droplets, compared with the state of the art.
[0071] FIG. 9 shows measured results on various devices corresponding to the present invention. Respectively the measured pressure loss between pressure side and suction side is thereby determined, which pressure loss occurs during separation of specific particle sizes or is required for separation of such particle sizes. The smaller the occurring pressure loss for separation of particles with a specific particle size, the greater is the efficiency of the respective oil-separating valve.
[0072] In FIG. 9, the measured results are plotted for a device according to FIG. 1 from the state of the art (without cone without coating) in which the suction-side end of the walls of the gas through-openings is not chamfered conically and the spring tongue has no coating.
[0073] Furthermore, measured results are illustrated with devices which have in addition a coating of the spring tongue with 0.4 mm FVMQ in which the suction-side end of the walls of the gas through-openings is not chamfered conically (without cone with coating) and also measured results with a device in which both the wall according to FIG. 5B is chamfered conically and the spring tongue is provided with a 0.4 mm thick coating made of FVMQ (with cone and coating).
[0074] It is shown that in fact the coating of the spring tongue according to the invention leads to great improvement in the separation efficiency. If in addition the suction-side end of the walls of the gas through-openings are also chamfered conically, then the separation efficiency is further improved disproportionately.
[0075] In the partial FIGS. 10A, 10B and 10C, FIG. 10 shows three alternative embodiments of spring elements 20 in plan view, as can be used in the device 1 according to the invention. Differently from the spring elements 20 of the preceding embodiments, configured as spring tongues 21, the spring elements 20 shown here have an essentially round configuration. The connection to the valve body is not effected directly via the retaining arms but in the edge region 28 surrounding the retaining arms.
[0076] The embodiment of FIG. 10A thereby has three retaining arms 26a, 26b, 26c which are disposed respectively offset relative to each other by 120 and extend helically. The retaining arms 26a, 26b, 26c in the embodiment of FIG. 10A are configured respectively with a constant width. Between the retaining arms 26a, 26b, 26c, slots or narrow recesses 27a, 27b, 27c are configured, which widen during opening of the valve and narrow during closure of the valve. As in the preceding embodiments, the valve element 20 thereby moves essentially parallel to the plane of the valve body.
[0077] In the embodiment of FIG. 10B, the valve element 20 is fixed or is to be fixed via four retaining arms 26a to 26d and the edge region 18. The retaining arms 26a to 26d hereby have a width which changes over their course, just as the recesses 27a to 27d. The retaining arms are configured rotationally-symmetrically relative to each other. Their shape can be changed by rotation by 90 or an integral multiple of 90 about the centre of rotation.
[0078] The embodiment of FIG. 10C has a branched retaining arm system which is regarded here as one retaining arm 26 since all of the branches are connected to each other. As in both embodiments of FIGS. 10A and 10B, the movement of the spring element 20 is effected essentially parallel to the plane of a valve body 5, not shown here.
[0079] In FIG. 11, a device according to the invention with a spring element 20, comparable to that of FIG. 10A, is shown in section in the opened state of the valve 2. The cross-section is thereby similar to that of FIG. 4A. Relative to FIG. 4; the projection of the walls 11 beyond the layer 5A is reduced, the total wall portion 11 is configured conically tapering and no cylindrical portion of the wall 11 is provided. The spring element 20 is connected via in total three retaining arms, only the two retaining arms 26a, 26b being visible in the illustrated section and the fixing regions being situated outside the shown section.
[0080] In FIG. 12, a device 1 according to the invention is shown in side view in both partial pictures 12A and 12B, FIG. 12A thereby shows the closed state, FIG. 12B the opened state of the valve. The spring element 20 is manufactured from an elastomer-coated material which is closed-pore completely on one side, for example a metal sheet, so that the coating 23 extends up to the edges of the spring element 20. Differently from the preceding embodiments, the spring element 20 is fixed via only one retaining arm 26 to the valve body or the baseplate 5 and is hence configured as spring tongue. Because of the one-sided fixing in the fixing region 25, the spring element 20 configured as spring tongue 21 is raised in a tilting movement from the cover region 13 and opens the latteras a function of the arrangement and the spacing of the through-openings, covered in common by one spring element, and the elasticity of the spring element and its coatingeither simultaneously or successively. This can be advantageous in particular if switching states of the device are consequently achievable in which a part of the through-openings is opened whilst another part of the through-openings is still closed by the spring element 20. Also in the case of a spring tongue coated in this way, the separation performance of the gap between the valve opening and the spring tongue is improved by the closed-pore, elastomeric coating.
[0081] It is essential here, as therefore for the entire present invention, that the spring element is coated elastomerically such that the separation performance for oil mist or oil droplets at the spring element is improved. Other properties of the elastomeric material need not thereby be considered, for example its cushioning properties on the resilient behaviour of the spring element or the closing behaviour of the spring element since this is not important in the present invention.
