Device

Abstract

The invention relates to a device, in particular in the form of a gap filter nozzle, having a connection housing (10) which has a fluid connection point (16, 18) on each of two opposite sides (12, 14) and which comprises, in between, an installation space (20). Into said installation space, there is inserted an inner body (26) which is provided with a nozzle (22) and with a nozzle channel (24) connected to said nozzle and which, in the direction of one (16) of the two fluid connection points (16, 18), jointly delimits an annular gap (28). Said annular gap serves as a type of filter for preventing particulate contamination in the fluid and is adjoined in the direction of fluid flow by a fluid chamber (32), in the direction of which the nozzle (22) in the inner body (26) opens, said nozzle being fluid-conductingly connected via the nozzle channel (24) to the other fluid connection point (18) of the connection housing (10). The device is characterized in that a sleeve-shaped intermediate piece (36) is inserted into the installation space (20) and, together with the inner body (26), delimits the annular gap (28), said intermediate piece being connected to the inner body (26), preferably by means of a detent connection (38).

Description

[0001] 40cdh / 131996AA / O

[0002] HYDAC MOBILHYDRAULIK GMBH

[0003] Industriestraße, 66280 Sulzbach / Saar, Germany

[0004] device

[0005] The invention relates to a device, in particular in the form of a gap filter nozzle, with a connection housing which has a fluid connection point on each of two opposite sides and which includes an installation space in between, into which an inner body provided with a nozzle and a nozzle channel connected thereto is inserted, which in the direction of one of the two fluid connection points defines an annular gap which serves as a kind of filter to prevent particulate contamination in the fluid, and to which a fluid chamber adjoins in the direction of fluid flow, in the direction of which the nozzle opens in the inner body, which is connected via the nozzle channel to the other fluid connection point of the connection housing in a fluid-carrying manner.

[0006] DE 10 2020 007 053 A1 discloses a test device for a fluidic pump assembly that can be driven by a drive unit and whose pump speed is known. This results in a defined fluid volume flow on the discharge side of the pump assembly, which is at least temporarily guided through a pressure control device in the form of a measuring orifice. During operation of the pump assembly, this orifice causes a pressure drop. With this continuous decrease in pressure, an evaluation device in the form of a pressure sensor indicates a reduced functionality of the pump assembly. Accordingly, with this test device, it is possible to address a potential failure of a hydraulic circuit by prematurely replacing the pump assembly without risking consequential damage to the hydraulic circuit and connected consumers.

[0007] The fluids used in this context, particularly hydraulic oil, are regularly subject to some degree of particulate contamination, for example, caused by component wear, which can impair the function of the orifice plate, even leading to its complete failure. To address the problem of orifices, nozzles, throttles, etc., becoming clogged in hydraulic systems, so-called upstream and / or downstream filters are frequently employed. These reliably remove particulate contamination from the fluid before it encounters a hydraulic resistance with a predefined, free, flowable cross-sectional area, such as an orifice plate. This effectively solves the problem of clogged hydraulic resistances with a predefined flow diameter; however, the installation of additional upstream and / or downstream filters in the hydraulic circuit is technically complex and therefore costly.This has long been recognized in practice, and to counteract the associated disadvantages, special devices, particularly in the form of slotted filter nozzles, have been proposed, as mentioned earlier. Such slotted filter nozzles are readily available on the market in a wide variety of technical designs, offered by various suppliers.

[0008] Such slotted filter nozzles, or nozzles with blockage protection, have an annular gap on their fluid inlet side between an outer circumference of the inner body and an inner circumference of an associated connecting or intermediate piece. This gap retains particles before they enter a nozzle with its associated nozzle channel, both of which are housed within the inner body. In this respect, the annular gap performs a filtering function. The gap width is typically about one-third or less of the diameter of the subsequent nozzle (viewed in the fluid direction), which can also function as a measuring orifice, as explained above.During operation of the gap filter nozzle, the highest flow velocity occurs in the nozzle itself, regularly formed by a bore with a reduced diameter compared to a fluid space formed by a circumferential annular channel in the inner body, which is volumetrically expanded compared to the annular gap and directly adjoins this annular gap in the direction of fluid flow.

[0009] The nozzle, with its reduced bore cross-section, opens at a right angle on its other side facing away from the annular gap into a withdrawal or nozzle channel with a wider cross-section, which in turn opens into a screw-in aid by means of which the device or the gap filter nozzle can be fixed in a third component, such as an associated receiving housing, which is provided with a fluid inlet and a fluid outlet and serves the flow of the fluid through the gap filter nozzle as a whole.

[0010] Overall, this results in a reduced risk of the annular gap becoming clogged or blocked by particles carried in the fluid flow. Contaminants are thus trapped in the annular gap, which acts as a kind of particle filter. Despite the presence of impurities in the fluid flow, this type of gap filter nozzle design has the advantage that the nozzle's function is always guaranteed during operation. However, the gap width of the annular gap must always be matched to the bore diameter of the nozzle in the inner body to ensure that the fluid flow is not adversely affected. Such gap filter nozzles can also be used to smooth out pressure surges in hydraulic systems during operation.At least some of the slotted filter nozzles freely available on the market have an external thread on their connecting piece for securing it in a third-party component, such as a housing. This external thread forms a continuous threaded section with a corresponding internal thread in the housing, running from the beginning to the end of the connecting piece. In this respect, the known connecting piece forms a stop within the thread runout on its free front face, which defines a cavity in which the inner body, forming the annular gap, is received. The peculiarity is that no defined torque can be applied when screwing it into the third-party component, thus preventing, or at least impairing, a secure and defined fastening of the slotted filter nozzle in the third-party component.The screwing in is done using an actuating tool, such as an Allen key, which engages in an internal hexagon recess on the other free end face of the connector during the screwing process, with the nozzle channel opening into this internal hexagon recess, which is permanently connected to the nozzle on the inlet side and carries fluid or media.

[0011] Furthermore, in the known solution, the inner body, which forms the annular gap, is secured by means of a tapered external thread in a corresponding internal thread in the connector. For this securing process of the inner body in the connector, an additional internal hexagonal recess is provided in the inner body. This recess connects to the internal hexagonal recess of the connector, which has a smaller engagement width. A further, smaller engagement tool is required for this. This recess, acting as an additional fluid-carrying component, ensures the connection of the nozzle to the fluid outlet of the connector via the nozzle channel. Creating this additional internal hexagonal recess in the inner body is also complex, as is generating the aforementioned tapered thread section between the inner body and the connector.

[0012] Based on this prior art, the invention aims to further improve known devices, which are technically referred to as slotted filter nozzles. A device, particularly in the form of a slotted filter nozzle, with all the features of claim 1, achieves this objective.

[0013] By inserting a sleeve-shaped intermediate piece into the installation space, as described in the characterizing part of claim 1, which defines the annular gap with the inner body and is connected to the inner body, preferably via a snap-fit ​​connection, a compact and reliable gap filter nozzle is obtained that can also be manufactured cost-effectively. This eliminates the need for an additional, complex threaded section between the inner body and the sleeve-shaped intermediate piece. Consequently, no further screw-in aid in the form of an internal hexagon socket is required for making the connection; rather, the entire gap filter nozzle can be secured in a third component, such as a connection housing, using only one screw-in aid.

[0014] In a preferred embodiment of the device according to the invention, the sleeve-shaped intermediate piece is received into a receiving housing of a third component at a radial distance, forming the annular gap, and is positioned on one side, facing a fluid connection point, with a contact cone against the receiving housing and opens into a connecting chamfer of the fluid connection point with a predefinable projection, preferably with a predefinable conicity.Thus, when the connection housing is screwed into the receiving housing of a third-party component, the sleeve-shaped intermediate piece is inevitably engaged via the aforementioned locking connection until it can be supported against the end face of the fluid connection point in the receiving housing in a force-fit and form-fit manner. The stop formed in this way provides a defined torque for screwing in the connection housing, ensuring that the slotted filter nozzle is always reliably secured in the receiving housing. This defined securing torque is reliably achieved even after repeated installation and removal of the connection housing relative to the receiving housing.

[0015] In a further particularly preferred embodiment of the device according to the invention, the inner body has a projection, preferably obtained by embossing, to form the latching connection. This projection engages in an adjacent recess in the intermediate piece. In this way, a secure latching connection can be achieved by a simple embossing process on both the inside of the intermediate piece and on the outside of the cylindrical inner body in the area of ​​the latching connection to be made. Other latching connections are also possible, for example, where a nose-like projection of the intermediate piece engages in a corresponding annular recess in the inner body, forming a type of snap or latching connection.Preferably, the locking connection is designed such that it can be separated again if necessary, i.e., the sleeve-shaped hollow cylindrical intermediate piece can be pulled off the cylindrical inner body in this area. Preferably, both the embossed projection and the embossed recess are arranged circumferentially on the inner body and the intermediate piece, respectively. In another preferred embodiment of the device according to the invention, the inner body, as part of the connection housing, has an external thread in the direction of the other fluid connection point, the outer diameter of which is larger than the outer diameter of the intermediate piece. Preferably, the inner body has a shoulder at the transition to the external thread, against which the other free end face of the intermediate piece rests.The shoulder allows the clamping forces applied by means of the screw-in aid to be transferred from the connector to the intermediate piece in order to bring it securely into a final position in the receiving housing.

[0016] In a further preferred embodiment of the device according to the invention, one free end face of the inner body, which is opposite one fluid connection point, forms a plane that is arranged transversely to the central or longitudinal axis of the intermediate piece and limits the fluid connection point serving as the fluid inlet in the direction of the annular gap. In this way, precise control of the size of the annular gap is possible.

[0017] In a further preferred embodiment of the device according to the invention, the inner body has a screw-in aid for torque transmission in the direction of the other fluid connection point serving as the fluid outlet, preferably in the form of an internal hexagon. Preferably, an annular passage is provided between the nozzle or fluid channel and the screw-in aid within the inner body, the diameter of which is larger than the diameter of the fluid or nozzle channel and the diameter of the screw-in aid. Instead of an internal hexagon socket, an internal hexagon, preferably one according to ISO 10664, is used for the engagement of a corresponding actuating tool, which enables improved torque transmission for securing the connection piece in the receiving housing.In a further particularly preferred embodiment of the device according to the invention, the other fluid connection point widens outwards in the receiving housing, preferably conically, and thus enlarges the installation space in the connection housing to such an extent that the slotted filter nozzle can be inserted into the receiving housing as a whole by screwing it in. In this way, the slotted filter nozzle can be reliably inserted into the receiving housing of a complete hydraulic system with the third component from one side and subsequently operated fluidically.

[0018] The device according to the invention will now be explained in more detail with reference to an exemplary embodiment as shown in the drawing. The only [item] shown is...

[0019] The figure, in a general and not to scale representation, shows a longitudinal section through the slotted filter nozzle, which is inserted into an associated receiving housing of a third component, which is only partially shown.

[0020] The longitudinal section shown in the figure illustrates the essential components of the device as a whole, which is designed in the form of a slotted filter nozzle. The slotted filter nozzle has a concentrically stepped connection housing 10, which has a fluid connection point 16 or 18 on each of two opposite sides 12 and 14. An installation space 20 is enclosed between these points, into which an inner body 26, equipped with a nozzle 22 and a fluid or nozzle channel 24 connected thereto, is inserted. In the present embodiment, this inner body 26 is an integral part of the housing 10.In the direction of the fluid connection point 16, which serves as the fluid inlet, a preferably circumferential annular gap 28 is defined by the cylindrical inner body 26. This gap acts as a filter to prevent particulate contamination in the fluid, which, viewed in the direction of fluid flow, is supplied as a whole to the gap filter nozzle via the fluid inlet 16. To form this annular gap 18, the diameter of the inner body 26 is reduced at its left free end (as viewed in the figure) compared to the rest of the inner body 26, thus forming a kind of inlet stage 30.

[0021] The free radial gap width of the annular gap 28 and its axial installation length depend on the fluid used and, in particular, on the diameter ratios at the nozzle 22. Both the annular gap 28 and the nozzle 22 each form a hydraulic resistance that limits the free flow cross-section within the slotted filter nozzle. A hydraulic resistance can be formed by a throttle, an orifice, or a nozzle, with the technical term "throttle" often being a generic term encompassing both orifices and nozzles. In this respect, both nozzles and orifices, as simple flow control valves, are considered throttling devices. The difference between a nozzle and an orifice lies in the fact that the cross-sectional constriction is gradual in the nozzle to achieve a velocity change with minimal loss, whereas an orifice produces a more abrupt change in cross-section.The aperture therefore represents a cross-sectional constriction where the length of the opening is regularly smaller than its diameter. Given this, the nozzle designated 22 can also be considered an aperture.

[0022] With the specified orifices or nozzle geometries, turbulence arises even at low Reynolds numbers according to the principles of fluid mechanics, so that the flow rate depends only on the pressure gradient and essentially no longer on the viscosity of the fluid. Therefore, whenever a nozzle 22 and an associated slotted filter nozzle are mentioned below, this regularly includes an orifice or orifice geometry. As can also be seen from the figure, a fluid chamber 32, which is partially enlarged in diameter and results from a circumferential annular groove in the inner body 26 that adjoins the inlet stage 30, is located downstream of the annular gap 28 in the direction of fluid flow. The fluid chamber 32 is thus volumetrically larger than the fluid inlet volume limited by the annular gap 28.The annular fluid chamber 32 also extends axially parallel to a central or longitudinal axis 34 of the device over a greater axial length than the comparable axial length of the annular gap 28. The aforementioned orifice-shaped nozzle 22 opens into this fluid chamber 32, its other end exiting at a right angle into the fluid or nozzle channel 24, which is formed in the connection housing 10 with the inner body 26 in the form of a blind hole. The other end of the aforementioned nozzle channel 24 opens towards the second fluid connection point 18, which forms the fluid outlet.

[0023] Furthermore, a sleeve-shaped intermediate piece 36 is inserted into the installation space 20. As a component of the gap filter nozzle, its front free end face forms one side 12 of the connection housing 10. The inner circumference of this intermediate piece 36, in conjunction with the outer circumference of the inlet stage 30 as part of the inner body 26, defines the aforementioned annular gap 28. The inlet stage 30 is set back by a predefinable amount along its central or longitudinal axis 34 relative to the outermost end of the intermediate piece 36, which is inclined in this respect. The intermediate piece 36 is also connected to the inner body 26, and thus to the connection housing 10, at its other, opposite end region via a snap-fit ​​connection 38.

[0024] The sleeve-shaped intermediate piece 36 is received into a receiving housing 40 of a third component (not shown) at a radial distance, forming an annular gap 28, and is pressed against the receiving housing 40 on one side facing a fluid connection point 16 by means of a contact cone 42. Furthermore, the contact cone 42 projects with a predefinable radial overhang towards the inlet stage 30 of the inner body 26, simultaneously limiting the annular gap 28. In this respect, the contact cone 42 opens into a connecting chamfer 44 of the fluid connection point 16, which is formed by the receiving housing 40.The third component mentioned, with its receiving housing 40, can be part of a total hydraulic system (not shown) in order to prevent particle contamination from the connected hydraulic circuit by means of the slotted filter nozzle, whereby the slotted filter nozzle simultaneously provides a nozzle or aperture function for the fluid flow by means of the bore 22.

[0025] For a precise fit of the intermediate piece 36 into the corresponding receiving housing 40, an annular space 46 is created between these components, forming a radial distance and thus compensating for tolerances between the components. To form the aforementioned snap-fit ​​connection, the inner body 26 has a projection on its outer circumference that engages in an adjacent recess in the intermediate piece 36. The resulting geometric change in the associated metallic components can be caused by embossing.In order for the intermediate piece 36 to be able to overcome the embossed projection of the inner body 26 more or less without difficulty when moving together, the intermediate piece 46 has a conical insertion ramp 50 at its other free end, which abuts a projecting shoulder 48 in the connecting housing 10. This ramp forms a kind of truncated cone on the inner circumference with a taper oriented towards the entry step 30, thus enabling the intermediate piece 36 to widen in this area so that the projection on the inner body 26 can be overcome, with the proviso that the locking connection 38 with the associated adjacent recess in the intermediate piece 36 is subsequently formed.

[0026] If necessary, the intermediate piece 36 can be pulled off the connection housing 10 with the inner body 26, although this requires an opposing force to release the locking connection 38. Furthermore, in an initial state, a gap (not shown) may exist in the area of ​​the shoulder 48 between the connection housing 10 and the adjacent free end face of the intermediate piece 36. This gap serves as additional compensation for play or tolerances and is eliminated as soon as the connection housing 10 is fully screwed into the receiving housing 40 and the intermediate piece 36 reaches its front stop position in the receiving housing 40 via the contact cone 42.Preferably, both the projection and the recess of which the locking connection 38 consists are arranged circumferentially on the outer circumference of the inner body 26 and on the inner circumference of the intermediate piece 36, which is designed as a hollow cylinder, has a uniform wall thickness and, in the fixed state, terminates on its outer circumference at least with the shoulder 48 of the connection housing 10.

[0027] It is understood that other types of connections are also possible for connecting the inner body 26 with the intermediate piece 36.

[0028] As can be further seen from the figure, the inner body 26, which merges seamlessly into the connection housing 10, has an external thread 52 in the direction of the other fluid connection point 18, the outer diameter of which is in any case larger than the outer diameter of the intermediate piece 36. This external thread 52 begins at the outlet of the shoulder 48 and extends to the rear second side 14 of the connection housing 10. Furthermore, one free end face of the inner body 26, which is opposite one fluid connection point 16, forms a plane 54. This plane, arranged transversely to the central or longitudinal axis 34 of the intermediate piece 36, defines a fluid connection point 16 serving as a fluid inlet in the direction of the annular gap 28. This plane 54 is part of the inlet stage 30, which may be provided with a marking 56 for improved identification of the respective gap filter nozzle to be used in conjunction with the required installation direction.

[0029] The inner body 28, or the connection housing 10, has a screw-in aid 58 for torque transmission of an actuating tool (not shown) in the direction of the other fluid connection point 18, which serves as a fluid outlet. The screw-in aid 58 is preferably designed in the form of a so-called internal hexagon socket. This type of screw-in aid 58 is also known under the trademark TORX. In particular, a standardized internal hexagon socket with the standard designation ISO 10664 is used as the screw-in aid 58 in the present case. To facilitate the engagement of an actuating tool (not shown) with the screw-in aid 58, an annular passage 60 is provided between the nozzle or fluid channel 24 and the screw-in aid 58 within the inner body 26 as part of the connection housing 10. The diameter of this passage 60 is larger than the diameter of the nozzle channel 24 and larger than the diameter of the screw-in aid 58.In this way, the actuating tool has a free tool run-out at its free end face when engaging the screw-in aid 58, in the form of the aforementioned through-hole 60. Other screw-in aids are also possible here, for example in the form of an internal hexagon socket recess (not shown), and the like. However, the use of an internal hexagon socket enables improved torque transmission from the actuating tool via the connecting housing 10 with the inner body 26 into the intermediate piece 36, which must be brought into contact with the connecting chamfer 44 in the receiving housing 40 without play at its free end face.

[0030] As can be further seen from the figure, the other fluid connection point 18 widens outwards towards the receiving housing 40, preferably in the form of a conical extension 62. This enlarges the installation space 20 in the connection housing 10 to such an extent that the entire slotted filter nozzle can be screwed into the receiving housing 40. Overall, this results in a progressively wider flow space from the nozzle 22 towards the outlet extension 62, which improves the flow characteristics, particularly by making it unobstructed. Finally, it should be mentioned that the threaded section 64, formed by the external thread 52 of the connection housing 10 and the corresponding internal thread 66 of the receiving housing 40, is shown in the figure only as an example and not according to standards. This is due to a simplified representation to avoid unnecessarily cluttering the figure with details.

Claims

P a t e n t a n s p r ü c h e 1. Device, in particular in the form of a gap filter nozzle, with a connection housing (10) which has a fluid connection point (16, 18) on each of two opposite sides (12, 14) and which comprises an installation space (20) in between, into which an inner body (26) provided with a nozzle (22) and a nozzle channel (24) connected thereto is inserted, which in the direction of one (16) of the two fluid connection points (16, 18) defines an annular gap (28) which serves as a kind of filter to prevent particulate contamination in the fluid, and to which a fluid chamber (32) adjoins in the direction of fluid flow, in the direction of which the nozzle (22) opens in the inner body (26), which is fluid-carrying connected to the other fluid connection point (18) of the connection housing (10) via the nozzle channel (24), characterized in that a sleeve-shaped intermediate piece (36) is inserted into the installation space (20),which limits the annular gap (28) with the inner body (26) and which is connected to the inner body (26), preferably via a snap connection (38).

2. Device according to claim 1, characterized in that the sleeve-shaped intermediate piece (36) is received into a receiving housing (40) of a third component at a radial distance, forming the annular gap (28), and is positioned on one side facing a fluid connection point (16) with a contact cone (42) against the receiving housing (40) and opens into a connecting chamfer (44) of a fluid connection point (16) with a predefinable projection, preferably with a predefinable conicity.

3. Device according to claim 1 or 2, characterized in that, for forming the locking connection (38), at least the inner body (26) has a projection, preferably obtained by embossing, which engages in an adjacent recess in the intermediate piece (36).

4. Device according to one of the preceding claims, characterized in that both the projection and the recess are arranged circumferentially on the inner body (26) or on the intermediate piece (36).

5. Device according to one of the preceding claims, characterized in that the inner body (26) as part of the connection housing (10) has an external thread (52) in the direction of the other fluid connection point (18), the outer diameter of which is larger than the outer diameter of the intermediate piece (36).

6. Device according to one of the preceding claims, characterized in that the inner body (26) has a shoulder (48) at the point of transition to the external thread (52), against which the other free end face of the intermediate piece (36) rests.

7. Device according to one of the preceding claims, characterized in that the one free end face of the inner body (26), which is opposite the one fluid connection point (16), forms a plane (54) which is arranged transversely to a central or longitudinal axis (34) of the intermediate piece (36) and limits the one fluid connection point (16) serving as a fluid inlet in the direction of the annular gap (28).

8. Device according to one of the preceding claims, characterized in that the inner body has a screw-in aid (58) for torque transmission in the direction of the other fluid connection point (18) serving as fluid outlet, preferably in the form of an internal hexagon. cdh / 131996AA / O 17 9. Device according to one of the preceding claims, characterized in that an annular passageway (60) is provided between the nozzle channel (24) and the screw-in aid (58) within the inner body (26), the diameter of which is larger than the diameter of the nozzle channel (24) and than the diameter of the screw-in aid (58).

10. Device according to one of the preceding claims, characterized in that the other fluid connection point (18) widens outwards in the receiving housing (40), preferably conically (62), and increases the installation space (20) in the connection housing (10) outwards in such a way that the insertion of the slotted filter nozzle into the receiving housing (40) by screwing it in is made possible.

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