Oil separation device for crankcase ventilation of an internal combustion engine

Abstract

The invention relates to an oil separation device (10) for crankcase ventilation of an internal combustion engine, comprising a support body (11) comprising an inlet line (12) for flowing blow-by gas (13) having an inlet end and an outlet end, and a gap-defining element (15), wherein at least one annular gap (5, 6) is formed or can be formed between the gap-defining element (15) and the outlet end of the inlet line (12). A baffle wall (7, 8) is arranged downstream of the annular gap (5, 6). The oil separation device (10) comprises a circumferential wall (18) which surrounds the outer circumference of the gap-defining element (15) and is fixed relative to the support body (11).

Description

Technical Field

[0001] The present invention relates to an oil separator for crankcase ventilation of an internal combustion engine, the oil separator having the features of the preamble of claim 1. Background Technology

[0002] For example, oil separators with rigid discs capable of resisting spring force displacement are known from DE10051307B4, EP1285152B1 and WO2016 / 015976A1.

[0003] The aforementioned type of oil separator can also be found in EP3192987A1. Here, the gap between the gap limiting element and the inlet pipe is adjusted according to the spring preload and spring constant, as well as the dynamic pressure of the bypass gas flowing through it. Accordingly, a pressure drop corresponding to a specific volumetric flow rate can be obtained. The separator must be designed to strike a trade-off between the available negative pressure supply, the generated bypass gas, and the negative pressure required in the crankcase. Therefore, a high negative pressure supply cannot always be utilized; instead, it must be regulated or throttled using additional components (especially pressure control valves) rather than taking advantage of this potential for more efficient separation. Furthermore, this design involves a trade-off in terms of available space.

[0004] Alternatively, electrically operated disc separators are known, for example, see EP1273335B1. Using such an active separator allows for advantageous control of the pressure drop across the separator. However, electrically operated disc separators are complex to design and therefore expensive. Summary of the Invention

[0005] The objective of this invention is to provide a relatively simple oil separation device with a small structural volume, improved separation efficiency by increasing the utilization of available negative pressure supply, and low manufacturing cost.

[0006] To address this issue, an oil separator for crankcase ventilation of an internal combustion engine is proposed. The oil separator includes a support body and a clearance limiting element. The support body includes an intake line with an inlet end and an outlet end for blow-by gas. At least one annular gap is formed or can be formed between the clearance limiting element and the outlet end of the intake line. A baffle wall is provided downstream of the annular gap.

[0007] Blow-by gas generated by crankcase ventilation is delivered via the intake manifold to its outlet. A clearance limiting element accommodates the blow-by gas carried by the oil-filled intake manifold. The clearance limiting element is located at the outlet of the intake manifold, preferably corresponding to an annular nozzle, so as to form or be able to form at least one gap between the intake manifold and the clearance limiting element. The annular gap is preferably uninterrupted, and more preferably annular, particularly preferably circular. In alternative embodiments, the annular gap may include non-circular, such as elliptical or oval shapes.

[0008] The blow-by gas flows at high speed through the annular gap. The gas exiting the annular gap impacts the downstream baffle wall. This causes radial flow of the gas. The gas flow exiting the annular gap flows roughly perpendicularly towards the baffle wall, where it is sharply deflected. Due to the inertia of oil and dust particles in the blow-by gas, they deposit on the baffle wall, thus forming an oil separator.

[0009] According to the present invention, the oil separation device includes a circumferential wall surrounding the outer periphery of the gap defining element and fixed relative to a support. Compared with the prior art that does not include the circumferential wall according to the present invention, the circumferential wall according to the present invention enables a simpler structure for the oil separation device.

[0010] For example, the circumferential wall can form, support, or enclose a baffle wall, particularly an outer baffle wall, which subsequently becomes stationary relative to the support. In this case, the outer baffle wall does not need to be part of the gap-limiting element, which greatly simplifies its structure. In a preferred embodiment, the outer baffle wall is formed from the inner surface of the circumferential wall.

[0011] The circumferential wall is preferably located outside the oil separator, particularly radially outside the gap-limiting element. The inner circumference of the circumferential wall is therefore advantageously larger than the outer circumference of the gap-limiting element.

[0012] According to a preferred further improvement, at least one impactor textured surface is provided on the inner surface of the circumferential wall. The impactor textured surface is advantageously configured such that the blow-by gas flowing from the annular gap (especially the outer annular gap) impacts the impactor textured surface substantially perpendicularly. Due to mass inertia, the blow-by gas penetrates the textured surface before being deflected. Oil droplets remain attached to the fibers of the textured surface, making an additional separation mechanism besides inertial separation effective. The separation of oil and blow-by gas can therefore be further improved by means of the impactor textured surface.

[0013] The impactor's felt is advantageously annular or segmental. Several other impactor felts (e.g., segmental) can also be provided. The outer periphery of the felt advantageously corresponds to the inner diameter of the retaining element, such that the felt is held within the retaining element.

[0014] An embodiment without an impactor-type velour surface is feasible.

[0015] Preferably, the oil separator includes a retaining element that closes the gap-limiting element. It is preferably in the form of a cap or cover. Advantageously, a circumferential wall is part of the retaining element. The circumferential wall and the retaining element are preferably formed as an integral part. Therefore, the circumferential wall and the retaining element are preferably integrally formed, which simplifies the manufacturability of the oil separator and reduces the number of parts. Advantageously, the circumferential wall is formed in a fixed manner, preferably in the form of a cylindrical surface, so it does not move with the gap-limiting element. Therefore, the gap-limiting element can be designed to have a smaller diameter, which reduces the tilt tolerance or corresponding angular error of the gap-limiting element. The mass of the gap-limiting element can also be reduced, which improves the responsiveness for adjusting the gap-limiting element. Furthermore, the circumferential wall surrounds and protects the internal moving parts of the oil separator, such as the gap-limiting element and springs (if present), thereby simplifying transportation and assembly.

[0016] In another embodiment, the circumferential wall is part of the support body and optionally integral with the support body, rather than part of the retaining element. In yet another embodiment, the circumferential wall is a separate component attached to the support body. In both cases, the cap-shaped retaining element is advantageously attached to the circumferential wall, in particular. Furthermore, it is conceivable that a portion of the circumferential wall is part of the retaining element, and another portion of the circumferential wall is part of the support body.

[0017] In an advantageous embodiment, axial guide ribs for the retaining element are provided on the support. Axial guide ribs simplify the assembly process and reduce the risk of the retaining element tipping or tilting.

[0018] An advantageous chamber is formed between the retaining element and the support body, the retaining element being particularly cap-shaped, and the gap-limiting element being advantageously displaceable within the support body. Thus, the retaining element functions as a cover or cap, sealing the chamber in which the gap-limiting element is disposed. In particular, the proposed oil separation device is characterized by small space requirements and high separation efficiency for a given volumetric flow rate.

[0019] Furthermore, a fastening unit is provided to act between the retaining element and the support, which is advantageously radially positioned outside the gap-limiting element. The fastening unit is advantageously a locking unit, which is easy to manufacture and allows for rapid assembly. With the locking unit, if needed, simple assembly can be achieved by snapping it into the support under spring preload, preferably with a spring. Arranging the fastening or locking unit outside the gap-limiting element results in a stable fastening with high precision in terms of installation angle.

[0020] Preferably, the retaining element includes one or more of the following features: one or more radial retaining webs; a central guide opening; a hub forming the guide opening; one or more vents; and / or a reinforcing ring radially disposed between the circumferential wall and the hub. These elements facilitate the simple, stable, and efficient construction of a breathable retaining element or a breathable end face of a retaining element.

[0021] The impactor's textured surface is advantageously attached to, and in particular welded to, the retaining element. The impactor's textured surface is thus attached to the retaining element in a way that prevents loss and saves space.

[0022] The impactor's felt is preferably made of a weldable material or plastic, especially a material that can be ultrasonically welded. The retaining element is preferably made of a thermoplastic material. The impactor's felt is preferably welded to the retaining element, especially by ultrasonic welding.

[0023] Furthermore, it is proposed that the retaining element includes an annular and radially inwardly projecting protrusion that axially defines the outer baffle wall, wherein the impactor textured surface covers at least a portion of the outer baffle wall and the protrusion. Therefore, the assembly of the impactor textured surface can be simplified by the abutment of the protrusion. Simultaneously, the sides of the impactor textured surface can cover the outside, thereby improving durability.

[0024] In an advantageous embodiment, the impactor textured surface includes at least one weld point and / or weld on the protrusion and at least one weld point and / or weld on the axial end face of the retaining element. This allows the impactor textured surface to be welded to the retaining element at both edges, thereby enabling permanent attachment of the impactor textured surface, which simplifies manufacturing. Furthermore, the weld points and / or welds can be generated from the same direction, further simplifying manufacturing.

[0025] A further improvement proposes providing at least one energy guide for ultrasonic welding. Due to energy concentration, the energy guide allows for rapid welding while achieving maximum strength.

[0026] Preferably, an outer annular gap is formed or can be formed on the outer wall of the intake pipe between the gap limiting element and the outlet end, wherein an outer baffle wall is provided downstream of the outer annular gap. Additionally or alternatively, an inner annular gap is formed or can be formed on the inner wall of the intake pipe between the gap limiting element and the outlet end, wherein an inner baffle wall is provided downstream of the inner annular gap. Gas flows at high speed through the inner annular gap and / or the outer annular gap, wherein, if applicable, the airflow is split between the two annular gaps. Gas exiting through the respective annular gap impacts the downstream baffle wall, wherein the portion of the airflow exiting through the outer annular gap flows in a direction perpendicular to the outer baffle wall and / or the portion of the airflow exiting through the inner annular gap flows in a direction perpendicular to the inner baffle wall. Therefore, for the inner and outer annular gaps, the flow directions of the exiting airflow are different, preferably opposite. In the case of two annular gaps, this results in radially inward airflow and radially outward airflow. The inner annular gap preferably has a smaller circumference and / or diameter than the outer annular gap.

[0027] A gap-limiting element is disposed at the outlet end of the intake line. At least one annular gap, preferably at least two annular gaps, are formed between the intake line and the gap-limiting element by the distance from the gap-limiting element to the outlet end. One or more annular gaps are preferably uninterrupted and more preferably annular, especially circular. Furthermore, in alternative embodiments, for example, one or more annular gaps may independently comprise non-circular shapes, such as elliptical or oval shapes.

[0028] In a preferred embodiment, the inner and outer annular gaps are concentrically arranged. In another particularly advantageous embodiment, the distance between the two concentrically arranged annular gaps is equal. In yet another preferred embodiment, the inner and outer annular gaps are arranged in the same plane. This arrangement of the annular gaps in the same plane simplifies manufacturing and ensures equal separation efficiencies for the inner and outer annular gaps. Preferably, the inner and outer baffle walls are concentrically arranged relative to each other, which also provides uniformly high separation efficiency along the entire length of the two annular gaps.

[0029] Preferably, the inner baffle wall and / or the outer baffle wall are annular in shape. In particular, the baffle wall can preferably be circular. However, alternative advantageous embodiments of annular baffle walls are also possible, for example, as oval, elliptical, or circular shapes.

[0030] In an advantageous embodiment, a gap-limiting element is proposed to form an inner baffle wall. The gap-limiting element and the inner baffle wall are preferably integral. Compared to the outer baffle wall, the inner baffle wall is lighter due to its smaller diameter, which relatively little increases the movable mass of the gap-limiting element. Furthermore, the inner baffle wall is internally protected and therefore less likely to be damaged during transport and assembly.

[0031] In an advantageous embodiment, the adjustment of the gap-limiting element is passive, i.e., without the supply of external energy, particularly electrical energy. Preferably, the gap-limiting element is adjustable against the force of a spring, wherein the spring holds the gap-limiting element in a closed position at rest or idle, and the gap-limiting element is able to open against the force of the spring when air pressure is applied to the gap-limiting element, wherein, within the operating range, the gap width increases with the increase of the applied gas pressure. Advantageously, a spring configured to apply a preload to the gap-limiting element is thus provided. Advantageously, the spring is supported on both the holding element and the gap-limiting element, such that the compression spring can be advantageously used to generate a preload on the gap-limiting element in the direction toward the air outlet (closed position).

[0032] In another embodiment, the oil separator includes an actuator, particularly an electric actuator, such as an electromagnetic motor or electric motor, for actively adjusting the gap limiting element relative to the outlet end of the intake line. Therefore, the separation characteristics of the oil separator and / or the (under)pressure control of the oil separator can be actively adjusted as needed. Advantageously, the control device adjusts, controls, and / or regulates the gap width based on signals from at least one pressure sensor, a differential pressure sensor, and / or based on the engine operating diagram. Typically, the control device advantageously controls the gap width such that the gap width decreases (monotonically) with increasing engine load. In any case, the control device advantageously controls the gap width such that a negative pressure relative to atmospheric pressure is maintained in the crankcase under all engine operating conditions to prevent harmful gases from escaping into the environment under any circumstances.

[0033] Preferably, the actuator adjusts the gap-limiting element against the force of the spring. The spring is able to hold the gap-limiting element at the position of the maximum gap width of the annular gap when it is stationary, i.e., when the electric actuator is de-energized. In this case, when the engine is idling and under low load, there is no need to operate the actuator, thereby saving energy.

[0034] Preferably, the intake line is attached to a support body, which is fixed to the housing. In particular, the support body can be connected to the housing of the oil separator, and especially can be inserted into or plugged into the housing.

[0035] Preferably, a method for manufacturing an oil separator having an impactor velvet surface disposed in a retaining element, as described at the beginning, is proposed, the method comprising the following steps:

[0036] - Place the impactor's felt side between the retaining element and the stamper.

[0037] - The impactor's velvet surface is pressed by a stamper, wherein the stamper includes at least two contact surfaces.

[0038] - The impactor's textured surface is pressed between the contact surface of the stamper, the radially inward protrusion, and the axial end face of the retaining element.

[0039] - Weld the impactor's felted surface to at least a portion of the surface of the protrusion and at least a portion of the surface of the axial end face.

[0040] - The impactor's felt surface at the separation contact surface.

[0041] For example, the textured surface of an impactor can be welded using ultrasonic welding. This manufacturing process enables the cost-effective production of oil separators. Attached Figure Description

[0042] The invention will now be explained with reference to preferred embodiments in the accompanying drawings. Thus, it is shown that:

[0043] Figure 1 A perspective view of the oil separator is shown from the gas outlet side;

[0044] Figure 2 A cross-sectional view of the oil separation device is shown;

[0045] Figure 3 An exploded view of the oil separation unit is shown;

[0046] Figure 4 A retaining element with an impactor-like velvet surface is shown;

[0047] Figure 5 Details of a cross-sectional view of the oil separation device are shown;

[0048] Figure 6a , 6b Figure 6c shows a schematic diagram of the manufacturing process of a retaining element with an impactor-like texture; and

[0049] Figure 7 A schematic diagram of a retaining element with an impactor-like velvet surface is shown. Detailed Implementation

[0050] Figure 1 A perspective view of an embodiment of the oil separator 10 is shown from the exhaust side. The oil separator 10 includes a support 11, a gap limiting element 15, a spring 54, and a retaining element 14 having an insert-type impactor velvet surface 30. See also... Figure 3 .

[0051] The retaining element 14 is in the form of a cap and includes a circumferential wall 18, which is cylindrical in this case, and an end 20 that is advantageously integrally or one-piece formed with the circumferential wall 18. The end 20 of the retaining element 14 includes at least one central guide ring 23 (in which the lifting guide 19 of the gap-limiting element 15 is guided in an axially displaceable manner), and at least one support ring 27, 28 radially disposed between the guide ring 23 and the circumferential wall 18. In the present case, two support rings are provided, namely a radially inner support ring 27 and a radially outer support ring 28. For example, the outer support ring 28 is integrally formed with the circumferential wall 18. The guide ring 23 and one or more support rings 27, 28 are connected to each other via a radially retaining web 21.

[0052] The retaining element 14 (especially end 20) includes one or more vents 22, 25. In the present case, the edges of the radially outgoing vents 25 and the edges of the radially ingoing vents 22 are provided. The vents 22, 25 are advantageously formed between the guide ring 23, one or more support rings 27, 28 and the radial retaining web.

[0053] The retaining element 14 is fastened to the support body 11 by a corresponding fastening unit, particularly by clamping by the locking unit 24. The fastening unit 24 is located radially outside the gap limiting element 15 or the intake line 12.

[0054] Therefore, the retaining element 14 advantageously includes at its center a guide opening 17 for the lifting guide 19 of the gap-limiting element 15, which is visible through the air outlets 22, 25 of the retaining element 14. Through the air outlet 25, the impactor velvet surface 30, which is disposed on the outer periphery of the circumferential wall 18, is visible. (See also...) Figure 2 The air outlets 22 and 25 are interrupted by multiple retaining webs 21, and thus are in a ring-shaped form.

[0055] Figure 2 A cross-sectional view of the oil separator 10 is shown. The support body 11 integrates the air inlet line 12 of the oil separator 10, which includes an inner wall 3 and an outer wall 4, and can be interrupted by a radial support 29, see also... Figure 3 .

[0056] Support 11 has, for example, annular (or annular segment) intake lines 12 for blow-by gas generated by crankcase ventilation of the internal combustion engine, such as Figure 2 As shown, the gas flows in from the right. The gas flow downstream of the oil separator is directed towards... Figure 2The exhaust side is on the left side. The support 11 is fixed to the housing, that is, fixedly disposed in and on the housing surrounding the oil separator 10. The housing can be the housing of the oil separator 10 or the housing of a larger functional unit (e.g., a cylinder head cover or functional module). In possible embodiments, multiple oil separators 10 can be used in the housing of a larger functional unit. They can be located on the same support 11 or on separate supports.

[0057] The oil separator 10 includes an adjustable gap-limiting element 15, which is movable against the spring force of the spring 54. The spring 54 is supported on a retaining element 14 on one side and on the gap-limiting element 15 on the other side, thereby applying a preload to the gap-limiting element 15 in the direction toward the outlet 22, i.e., in the closed position of the gap-limiting element 15 (when the engine is off or idling). When there is sufficient gas pressure in the intake line 12, the gap-limiting element 15 opens by axial displacement toward the retaining element, wherein the gap width of one or more annular gaps monotonically increases with increasing gas pressure. When the gas pressure in the intake line 12 decreases, the gap width of one or more annular gaps decreases due to the action of the spring 54 on the gap-limiting element 15.

[0058] The gap limiting element 15 is disposed at the outlet end on the inner wall 3 and outer wall 4 of the intake pipe 12, thereby forming or being able to form two gaps (especially an inner annular gap 5 and an outer annular gap 6) between the intake pipe 12 and the gap limiting element 15. In this advantageous embodiment, the two annular gaps 5 and 6 are formed continuously and are circular.

[0059] The blow-by gas 13 flows at high speed through the inner annular gap 5 and the outer annular gap 6, wherein the airflow is split between the two annular gaps 5 and 6. The inner annular gap 5 has a smaller circumference and / or diameter than the outer annular gap 6.

[0060] The gap limiting element 15 can be axially displaced relative to the outlet end of the intake line 12, so that the annular gaps 5 and 6 can occupy different gap widths. For example, the annular gaps 5 and 6 can also be closed. As previously described, this displacement can be passively caused by the gas pressure applied by the blow-by gas overcoming the spring force of the spring 54. In an alternative embodiment not shown, the displacement of the gap limiting element can also be achieved by active gap control or by a force applied by an actuator.

[0061] In an advantageous embodiment, the lifting guide 19 is centrally guided by the guide opening 17 of the retaining element 14, thereby guiding the lifting movement in a stable manner. Advantageously, a plurality of guide ribs 38 are provided inside the intake line 12 (see...). Figure 3It also guides and / or stabilizes the gap limiting element 15. By placing the gap limiting element 15 only linearly, rather than against the entire surface of the guide rib 38, it is intended to prevent it from becoming immobile or stuck (also by dust).

[0062] As previously described, the passive oil separator 10 preferably includes a spring 54 that generates a spring force that reduces the gap or annular gaps 5, 6 to a minimum gap width, or, in a possible embodiment, completely closes the annular gaps 5, 6, wherein the annular gaps 5, 6 are squeezed open to their maximum gap width as the gas pressure applied by the blow-by gas increases. In the active oil separator 10 with an actuator (not shown), the spring is preferably configured such that the spring force causes the maximum opening of the gap width of the annular gaps 5, 6, wherein the actuator preferably overcomes the spring force to reduce the gap width.

[0063] The gas flowing out through the annular gaps 5 and 6 impacts the downstream baffle walls 7 and 8. According to the splitting of the gas flow, the part flowing out through the inner annular gap 5 flows along the direction of the inner baffle wall 7, while the part flowing out through the outer annular gap 6 flows along the direction of the outer baffle wall 8.

[0064] In this embodiment, the inner baffle wall 7 is integrated with the gap limiting element 15, so that when the gap limiting element 15 moves due to the pressure of the gas leak and / or a possible actuator, the inner baffle wall 7 moves.

[0065] In this embodiment, the outer baffle wall 8 is integral with the retaining element 14. Furthermore, the outer baffle wall 8 is formed on the inner surface of the retaining element 14. Therefore, the outer baffle wall 8 does not move with the gap-limiting element 15.

[0066] In this embodiment, an impactor velvet surface 30 is advantageously provided on the front of the outer baffle wall 8, which is preferably welded to the retaining element 14.

[0067] In an alternative embodiment, the oil separator 10 can also be designed without the impactor surface 30. In this respect, the distance between the outer baffle wall 8 and the outer annular gap 6 can be adjusted.

[0068] The two airflows exiting through the annular gaps 5 and 6 move approximately perpendicularly toward the corresponding baffle walls 7 and 8 or the impactor surface 30 and are sharply deflected, wherein the impactor surface 30 in front of the outer baffle wall 8 further improves oil separation. Due to the inertia of oil and dust particles in the blow-by gas 13, they separate at the two baffle walls 7 and 8 in the impactor surface 30, respectively. The baffle walls 7 and 8 are preferably cylindrical, wherein the inner baffle wall 7 is associated with the outer surface of the cylinder, and the outer baffle wall 8 is associated with the inner surface of the cylinder.

[0069] Oil deposited on the baffle walls 7 and 8 advantageously follows the same path as air. Due to its high mass inertia, thicker droplets separated from the impactor surface 30 or the baffle walls 7 and 8 can be easily separated by a downstream baffle (not shown in the figure) and then returned to the engine oil circuit under gravity through the module's return line (also not shown in the figure).

[0070] Due to the complete 360° circumferential annular gaps 5 and 6 between the gap limiting element 15 and the intake pipe 12, the annular gaps 5 and 6 of the oil separator 10 have high separation efficiency. Therefore, the oil separator 10 can also be called a gap-type impactor or annular gap-type impactor, and due to the inner annular gap and the outer annular gaps 5 and 6, it can also be called a double-annular gap-type impactor.

[0071] The support 11, the gap limiting element 15, the retaining element 14, and / or the housing are made of plastic, particularly reinforced or unreinforced thermoplastic. The support 11 is advantageously configured as a partition wall within the housing and divides the interior of the housing into two spatial regions: a pre-separator space upstream of the oil separator 10 and a cleaning space downstream of the oil separator 10.

[0072] exist Figure 3 In the middle, the oil separation device 10 Figure 1 and Figure 2 The embodiment is shown in an exploded view. In this illustration, the fastening or locking unit 24 on the retaining element 14 can be seen from outside the annular gap 6 formed or potentially formed between the outlet end of the outer wall 4 and the gap defining element 15. Therefore, the locking unit 24 on the support 11 surrounds the outlet end of the intake line 12. On the retaining element 14, a corresponding locking unit 24 is disposed outside the outer baffle wall 8. See the assembled state. Figure 1 The locking unit 24 is correspondingly positioned outside the formed annular gap 6.

[0073] The support body 11 also advantageously includes a plurality of axially oriented guide ribs 48 arranged in annularly, which serve as guides when the retaining element 14 is installed and supports the retaining element 14 in the installed state. The support body 11 also advantageously includes a plurality of axially oriented guide ribs 38 arranged in annularly on the inner side of the wall of the intake line 12, which are used to guide and retain the clearance defining element 15.

[0074] Figure 4 A retaining element 14 is shown having an impactor suede 30 disposed in front of an outer baffle wall 8 (here cylindrical). Therefore, the impactor suede 30 preferably also has an annular or shape adapted to surround the cylindrical surface. Furthermore, a central opening 17, an external air outlet 25, and an internal air outlet 22 are visible.

[0075] The guide of the gap limiting element 15 can be coated with PTFE on one and / or both sides, or one of the components (in this embodiment, the central opening 17 of the retaining element 14 or the lifting guide 19 of the gap limiting element 15) can be made of a PTFE-containing material or other lubricating and / or decontaminating material with good sliding properties.

[0076] Figure 5 The diagram shows a detailed cross-sectional view of the oil separator 10 located within the area of ​​the outer baffle wall 8, with the impactor frosting 30 disposed on the front of the outer baffle wall, preferably welded thereto. The outer baffle wall 8 is located on one side (in... Figure 5 As shown in the figure on the left, it is axially defined by a radially inward protrusion 31. On the side opposite to the protrusion 31, the outer baffle wall 8 terminates at the axial end face 32 of the retaining element 14.

[0077] Figures 6a-6c Various stages of an advantageous manufacturing process for a retaining element 14 having an impactor velvet 30 are shown, wherein the impactor velvet 30 is welded to the retaining element 14 to secure the impactor velvet 30 to the retaining element 14.

[0078] The retaining element 14 is inserted into the support frame 37 to achieve the engagement process. The retaining element 14 includes an annular and radially inwardly projecting protrusion 31, which... Figures 6a-6c The diagram shows the outer baffle wall 8 defined downwards. For ultrasonic welding, it is advantageous to provide energy directing elements 34, particularly on the protrusion 31 and the axial end face 32. The energy directing elements 34 can be distributed over the entire circumference and / or formed as cones or points on the protruding edges.

[0079] Figure 6a An impactor suede 30 is shown positioned between the retaining element 14 and the stamper 35. The stamper 35 includes two contact surfaces 36 that are annular or partially circular in shape. The stamper 35 moves toward the retaining element 14.

[0080] If able to Figure 6b As seen, the impactor velvet 30 is pressed into the retaining element 14 by means of a stamper 35. Two contact surfaces 36 press the impactor velvet 30 against the protrusion 31 and against the axial end face 32. Furthermore, in this advantageous embodiment, the energy guide 34 is located in the area contacted by the contact surfaces 36. The stamper 35 softens and / or melts the impactor velvet 30, and, if necessary, also softens and / or melts the retaining element 14 in the area of ​​the contact surfaces 36. By applying pressure simultaneously with the stamper 35, the impactor velvet 30 is welded to the retaining element 14. Thus, welds 33 and / or weld points 33 are formed on the protrusion 31 and the axial end face 32, thereby welding the impactor velvet 30 at least to a portion of the surface of the protrusion 31 and a portion of the surface of the axial end face 32.

[0081] For example, welding can be achieved by ultrasonic waves coupled via the contact surface 36 of the stamper 35 or by a corresponding high-temperature treatment of the contact surface 36. The impactor textured surface 30 is at least partially made of thermoplastic material. The retaining element 14 is preferably also at least proportionally made of thermoplastic material.

[0082] exist Figure 6c In this configuration, the impactor surface 30 is welded to the retaining element 14, and the impactor 35 is raised upwards. The impactor surface 30 is thus permanently connected to the retaining element 14 and is positioned in front of the baffle wall 8. Therefore, the retaining element 14 can be assembled with the impactor surface 30 to form an oil separator 10.

[0083] exist Figure 7 In this process, it is advantageous to use ultrasonic welding of the impactor texture 30 or a pre-fabricated textured blank. When using a pre-fabricated textured blank, the impactor texture 30 can be welded only to one side (e.g., on the axial end face 32 of the retaining element 14), such as when it is possible to... Figure 7 As seen in the embodiment, it is pressed into the groove on the annular radially inward protrusion 31 on the other side. The fixing tip can be stably bonded.

[0084] In an embodiment not shown, an additional impactor textured surface is provided relative to the inner baffle wall 7 to further improve separation efficiency.

Claims

1. An oil separator (10) for crankcase ventilation of an internal combustion engine, comprising: - Support body (11), which includes an air inlet line (12) with an inlet end and an outlet end for flow leakage (13). - Gap limiting element (15). - wherein at least one annular gap (5, 6) is formed or can be formed between the gap limiting element (15) and the outlet end of the air intake line (12). -A baffle wall (7, 8) is provided downstream of the annular gap (5, 6). Its features are, - The oil separator (10) includes a circumferential wall (18) surrounding the outer periphery of the gap defining element (15) and fixed relative to the support (11). - The oil separation device (10) includes a retaining element (14) that closes the gap limiting element (15). - The circumferential wall (18) is part of the retaining element (14) and / or part of the support (11). -The retaining element (14) includes the edges of a plurality of air outlets (22, 25).

2. The oil separation device (10) according to claim 1, characterized in that, An impactor felt (30) is provided on the inner side of the circumferential wall (18).

3. The oil separation device (10) according to claim 1, characterized in that, A fastening unit is provided between the retaining element (14) and the support body (11).

4. The oil separation device (10) according to claim 1, characterized in that, The retaining element (14) includes one or more of the following features: - One or more radially retaining webs (21); -Guide opening (17); -Guide ring (23) for forming the guide opening (17); - One or more air outlets (22, 25); - At least one support ring (27, 28) is radially disposed between the circumferential wall (18) and the guide ring (23).

5. The oil separation device (10) according to claim 1, characterized in that, An axial guide rib (48) for the retaining element (14) is provided on the support body (11).

6. The oil separation device (10) according to claim 2, characterized in that, The impactor velvet (30) is fastened to the retaining element (14).

7. The oil separation device (10) according to claim 2, characterized in that, The retaining element (14) includes an annular and radially inwardly projecting portion (31) that axially defines the circumferential wall (18), wherein the impactor velvet (30) covers at least a portion of the circumferential wall (18) and the projecting portion (31).

8. The oil separation device (10) according to claim 7, characterized in that, The impactor surface (30) includes at least one weld point and / or weld on the protrusion (31) and at least one weld point and / or weld on the axial end face (32) of the retaining element (14).

9. The oil separation device (10) according to any one of claims 1 to 8, characterized in that, The support (11) includes an axial guide rib (38) inside the intake line (12) for guiding and / or retaining the gap limiting element (15).

10. The oil separation device (10) according to any one of claims 1 to 8, characterized in that, An outer annular gap (6) is formed or can be formed at the outer wall (4) of the air inlet pipe (12) between the gap limiting element (15) and the outlet end, wherein an outer baffle wall (8) is provided downstream of the outer annular gap (6).

11. The oil separation device (10) according to any one of claims 1 to 8, characterized in that, An inner annular gap (5) is formed or can be formed between the gap limiting element (15) and the outlet end at the inner wall (3) of the air inlet line (12), wherein an inner baffle wall (7) is provided downstream of the inner annular gap (5).

12. The oil separation device (10) according to any one of claims 1 to 8, comprising a spring (54) configured to apply a preload to the gap limiting element (15).

13. The oil separation device (10) according to any one of claims 1 to 8, comprising a drive actuator for displacing the gap limiting element (15) relative to the outlet end of the air inlet line (12).

14. The oil separation device (10) according to claim 3, characterized in that, The fastening unit is a locking unit (24).

15. The oil separation device (10) according to claim 4, characterized in that, The guide opening (17) is a central guide opening (17).

16. The oil separation device (10) according to claim 2, characterized in that, The impactor velvet (30) is welded to the retaining element (14).

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