Fluid coupling for the fluidic connection of fluid lines

Description

[0001] The present invention relates to a fluid coupling which is configured to connect fluid lines to each other fluidically, wherein the fluid coupling comprises a first fluid connection which is configured to be fluidically connected to a first of the fluid lines, and a second fluid connection which is configured to be fluidically connected to a second of the fluid lines.

[0002] Document DE 91 09 526 U1, which is considered the closest prior art, discloses a fluid coupling comprising a first fluid connection, a second fluid connection, a core element, and shell elements, wherein the shell elements surround the core element. Reference is also made to documents DE 20 2006 019578 U1, DE 89 00 869 U1, and US 5 228 721 A.

[0003] Known fluid couplings often have a complex design in which sections of the coupling designed for fluid flow and sections designed for crimping a fluid line to the coupling are seamlessly integrated. This can result in very high complexity of the fluid coupling and the associated manufacturing costs, as well as very high demands on the materials used.

[0004] It is therefore the object of the present invention to provide a cost-effective and safe connection of fluid lines which can overcome the aforementioned disadvantages.

[0005] This problem is solved according to the invention by a fluid coupling which is designed to connect fluid lines to each other fluidically, wherein the fluid coupling comprises: a first fluid connection which is designed to be fluidically connected to a first of the fluid lines, a second fluid connection which is designed to be fluidically connected to a second of the fluid lines, and at least two shell elements, wherein the fluid connections are formed separately from one another, wherein the fluid connections are in fluidic communication with one another in order to fluidically connect the fluid lines connected to the fluid coupling, wherein the fluid connections are formed integrally on a common core element of the fluid coupling, wherein the at least two shell elements are configured to surround the core element at least at each of the first and second fluid connections on its respective radial outer side, wherein the fluid coupling further comprises a press sleeve for each fluid connection, which is configured to be received on a section of the at least two shell elements radially surrounding a respective fluid connection, wherein the respective press sleeve is further configured to be plastically deformed radially inwards by a force acting radially outwards on the press sleeve.so that a corresponding fluid line is permanently and non-destructively connected to its respective fluid connection.

[0006] By dividing the fluid coupling into the core element, whose primary function is to guide the fluid, and shell elements, whose primary function is to hold the press sleeves relative to the core element, the wall thickness of the core element can be significantly reduced compared to conventional fluid couplings (where a corresponding section is often referred to as a "support body" or "support element"). This allows for a larger inner diameter of the fluid connections and / or the core element, thereby improving the fluid flow characteristics through the fluid coupling.Furthermore, the aforementioned division of the fluid coupling into core elements and shell elements allows for the targeted selection of materials advantageous for the respective application, so that, despite a potentially increased material requirement due to the division of the fluid coupling, a cost reduction can still be achieved. In particular, a comparatively inexpensive material can be selected for the shell elements.

[0007] Furthermore, it should be noted that the expression "the at least two shell elements are arranged to surround the core element at least at each of the first and second fluid ports on its respective radial outer side" does not necessarily imply a complete surrounding of the respective fluid port by the shell elements, but may also imply a partial surrounding of the respective fluid port by the shell elements.

[0008] In order to secure each press sleeve in its position on the shell elements in the assembled state of the fluid coupling, at least one locking lug can be provided at the respective free end of the shell elements on which a press sleeve is arranged, which is designed to engage with the press sleeve arranged there.

[0009] In an exemplary embodiment of the fluid coupling according to the invention, it can additionally comprise a third fluid connection, which is configured to be fluidically connected to a third fluid line. Thus, the fluid coupling can function as a branch or as a merging element for the fluids carried therein. The first fluid connection or the axis of the associated fluid flow channel and / or the third fluid connection or the axis of the associated fluid flow channel can form an angle of essentially 90° with the second fluid connection or the axis of the associated fluid flow channel, wherein, in particular, the first fluid connection or the axis of the associated fluid flow channel can also form an angle of essentially 180° with the third fluid connection or the axis of the associated fluid flow channel.Based on the above-described arrangement of the fluid connections to each other, the fluid coupling and in particular the core element of the fluid coupling can essentially have a T-shape.

[0010] Particularly in the case of a fluid coupling according to the invention with two fluid connections, a rotational locking mechanism for the core element relative to at least one shell element, and in particular both or all shell elements, can be provided. This rotational locking mechanism can be implemented, for example, by a corresponding projection on the core element which bears against at least one shell element.

[0011] Advantageously, the core element can have at least one recess, and in particular at least two recesses, on its outer surface, each configured to engage with a corresponding projection that protrudes from the inner surface of at least one shell element. In this way, the core element can be secured relative to the shell elements at least in an axial direction, with respect to a principal extension direction of the fluid flow channel of the core element, and in particular also in a rotational direction. Of course, it is also generally conceivable to completely or partially reverse the arrangement of the projection and recess, so that the core element has at least one projection on its outer surface and at least one shell element has at least one corresponding recess on its inner surface.

[0012] Here, at least one recess can be configured as a groove that completely circumferentially surrounds the outer surface of the core element. This allows the core element to be received in the shell elements in more than one relative position. For example, it is conceivable that the core element can be received in a first relative position and in a second relative position, which is rotated 180° around the axis of one of the fluid connections relative to the first relative position.

[0013] In this context, the projection, which is designed to engage with the corresponding recess of the core element in the assembled state of the fluid coupling, can also be distributed across the at least two shell elements such that the projection portions of the shell elements, in the assembled state of the fluid coupling, combine to form a projection that essentially encircles the core element completely. In other words, the projection can be distributed across at least two of the shell elements in such a way that the projection encircling the core element only becomes apparent in the assembled state of the fluid coupling or the shell elements.In this way, the core element can simply be inserted into one of the shell elements such that its recess (or, if applicable, its projection) engages with the projection (or, if applicable, a recess) of a shell element, and then at least one further shell element can be mounted. Thus, during the assembly of the fluid coupling, the core element is first secured to the first shell element, and then the at least one further shell element is secured to the core element, and consequently also the at least one further shell element relative to the first shell element.

[0014] In possible embodiments of the present invention, each of the fluid connections of the core element can have on its outer surface a plurality of rib-like projections which are designed to engage with the fluid line upon arrangement of a fluid line at the fluid connection and pressing of the crimp sleeve, in order to secure it against pull-out forces, and / or in a respective region of the at least two shell elements which radially surrounds a fluid connection, a plurality of rib-like projections can be arranged on an inner surface of the shell elements which are designed to engage with the fluid line upon arrangement of a fluid line at the fluid connection and pressing of the crimp sleeve, in order to secure it against pull-out forces.These rib-like protrusions can penetrate the material of the fluid line on its inside and / or outside during the crimping of the crimp sleeve and thus the fluid coupling with the fluid line, in order to improve the securing of the fluid line at the fluid coupling.

[0015] It can be advantageous that, viewed along the axis of the fluid flow channel of a respective fluid connection, the rib-like projections on the core element and the rib-like projections on the shell elements are arranged in an alternating, and in particular equally spaced, manner, that is to say, viewed along the aforementioned axis, over at least a part of the fluid connection, a rib-like projection on the core element, a rib-like projection on the shell elements, a rib-like projection on the core element, and so on, are always arranged alternately.

[0016] The respective fluid connections of the fluid coupling according to the invention for connection to a respective fluid line can be designed, in particular, such that they are free of separately designed or arranged sealing elements, such as O-rings. For such an O-ring-free connection between the fluid coupling and the fluid line, a radial deformation of the crimp sleeve without burr formation can be advantageous, since such burr formation can lead to localized leakage. A special type of crimping jaw can be used for this purpose, which can reduce or even prevent such burr formation.

[0017] Furthermore, a stop can be provided on at least one of the shell elements, which is designed to limit the sliding of a respective fluid line onto a fluid connection, wherein in particular the stop for the fluid line can be designed on the projection for engagement with the core element, and / or a contact surface can be provided on at least one of the shell elements, which is designed to limit the sliding of a respective crimp sleeve onto the shell elements in the assembled state of the fluid coupling, wherein in particular a distance of the stop for the fluid line from an adjacent free end of the shell elements in the assembled state of the fluid coupling can be greater than a distance of the contact surface for the crimp sleeve from the same free end of the shell elements.It should be added that the respective distance from the stop or contact surface to the adjacent free end of the shell elements can advantageously be measured along a direction that is essentially parallel to a central axis of the fluid flow channel of the respective fluid connection. Firstly, the stop for the fluid line and the contact surface for the crimp sleeve provide a defined end position for the fluid line or crimp sleeve, respectively. Secondly, if the distance of the stop for the fluid line from the adjacent free end of the shell elements is greater than the distance of the contact surface for the crimp sleeve from the same free end of the shell elements, it can be ensured that the crimp sleeve, or the sections of the shell elements arranged radially within the crimp sleeve, engage completely with the fluid line when the crimp sleeve is crimped.

[0018] The contact surface for the crimp sleeve can also provide an alignment aid for the crimping jaw for crimping the crimp sleeve.

[0019] In particular, the at least two shell elements can comprise plastic, especially polybutylene terephthalate (PBT) and / or fiber-reinforced polymers such as polyamide and / or polypropylene, and / or the core element can comprise plastic, especially polyoxymethylene or cross-linked polyethylene. As mentioned at the outset, a highly functional material can thus be selected for the core element, which, for example, is particularly temperature-resistant and / or acid-resistant. For the shell elements, on the other hand, a material can be selected that, for example, can withstand high mechanical stresses (e.g., impacts).

[0020] Preferably, the at least two shell elements can be designed as identical shell elements to each other. This reduces the number of different components of the fluid coupling, which in turn reduces tooling and manufacturing costs. Furthermore, the arrangement of the shell elements on the core element can be interchangeable, which in turn reduces the probability of assembly errors during the assembly of the fluid coupling.

[0021] At least two shell elements can be free of mutually compatible locking elements designed to secure the shell elements to one another. In this case, the shell elements can be secured relative to each other by engaging with the core element relative to it.

[0022] Furthermore, the at least two shell elements of the fluid coupling, in their assembled state, can be essentially closed, with the exception of the areas of the shell elements that radially overlap the fluid connections. The term "essentially" here can explicitly include the possibility that a boundary region between two adjacent shell elements may have a narrow gap and thus may not be watertight. The remaining essentially closed design of the shell elements can protect the core element, in particular, from mechanical damage acting on the fluid coupling.

[0023] Within the scope of the present invention, a respective press sleeve can be designed as a substantially cylindrical metal sleeve. The cylindrical shape of the metal sleeve can, in particular, be circular.

[0024] Furthermore, a crimp sleeve can have a collar at at least one longitudinal end, and in particular at both longitudinal ends. Such a collar can be designed such that the wall thickness of the crimp sleeve remains approximately the same compared to the essentially cylindrical section of the crimp sleeve, but that the inner diameter of the crimp sleeve increases in the region of the collar. In other words, a collar can be formed by the crimp sleeve expanding radially outwards in the region of the collar, at least on its outer surface, and in particular also on its inner surface.

[0025] Alternatively, the crimp sleeve can be designed such that it has a substantially constant inner diameter from one longitudinal end to the other. This can further improve the engagement with a locking lug, which is arranged on a free end of a shell element, with a longitudinal end of the crimp sleeve, in order to secure the crimp sleeve against unintentional detachment from the shell elements.

[0026] Advantageously, the at least two shell elements can have a radially outward-extending bulge on their outer surfaces in a region located between the fluid connections. It is conceivable that the wall thickness in the area of ​​a bulge increases compared to adjacent sections of the corresponding shell element, or that the wall thickness in the area of ​​a bulge remains essentially the same compared to an adjacent section of the same shell element. Such a bulge can improve the mechanical stability, such as torsional stiffness, of the shell element. The bulge on the radially outer side of a shell element can approximately replicate the shape of the associated core element of the fluid head plug.For example, in the case of a T-shaped core element, a corresponding essentially T-shaped shell element may have an essentially T-shaped bulge.

[0027] According to the invention, the at least two shell elements have a plurality of resilient webs in the area designed to receive a respective press sleeve. In the assembled state of the fluid coupling, these webs can extend parallel to one another. These webs can extend at least over the axial length of the corresponding press sleeve. More preferably, the resilient webs or the slots that penetrate the shell elements and thus, viewed in a circumferential direction, define the successive resilient webs, can extend from the free end of the shell elements to at least the contact surface for the press sleeve, and in particular even through the contact surface for the press sleeve.In the event that the resilient webs or the slots arranged between them extend through the contact surface for the crimp sleeve, the sections of the slots located on the side of the crimp sleeve opposite the free end of the shell elements can form a viewing window. This window allows for external inspection to determine whether a fluid line has been inserted into the fluid coupling up to the designated stop. The slot(s) that separate adjacent webs relative to the central axis of the associated fluid connection in the circumferential direction can also be designed to reduce the crimping forces necessary for the radial deformation of the resilient webs and, consequently, the crimp sleeve attached to them.In particular, the slots of a single shell element can penetrate the shell element in a direction parallel to each other. This allows cores used in injection molding during manufacturing to be easily removed from the manufactured shell element in a parallel manner. The slots of the fluid coupling, which are associated with a respective fluid connection, can be designed so that, when the fluid connection is pressed into the fluid line, they are essentially flush against each other and, in particular, form a closed ring. This allows it to be seen from the outside whether the fluid coupling has been correctly pressed into the fluid line at that point.

[0028] The present invention will now be described using an exemplary embodiment with reference to the accompanying drawings. It illustrates: Figure 1 shows a perspective view of a shell element and a core element of a fluid coupling according to the invention; Figure 2 shows a side view of the shell element made of Figure 1 ; and Figure 3 shows a side cross-sectional view of a fluid coupling, which is attached to its in Figure 3 The right side is connected to a fluid line, but not crimped.

[0029] In Figure 1 A fluid coupling according to the invention is generally designated by reference numeral 10. The fluid coupling 10 comprises a core element 12 and a shell element 14. A first fluid connection 16, a second fluid connection 18, and a third fluid connection 20 are arranged on the core element 12, each defining a fluid flow channel inside, the fluid flow channels of the three fluid connections 16, 18, 20 being in fluidic communication with each other.

[0030] The three fluid connections 16, 18, 20 are each designed to connect to a corresponding fluid line 22 (see Figure 3 ) to be introduced. To assign a defined end position to the insertion of each fluid line 22, a stop 24 is provided in the area of ​​each fluid connection, which is designed to limit the sliding of each fluid line 22 onto a fluid connection 16, 18, 20. The stop 24 is designed here as a surface of a projection which extends radially inwards from an inner side of the shell element 14. Each projection 24 engages on its radially inner side with a corresponding recess 26, which is formed on the core element 12. The three recesses 26 are designed here as, with respect to an axis of a respective fluid connection (in Figure 1As an example, the central axis of the associated fluid flow channel at fluid connection 18 is marked with the reference symbol X), and a completely circumferential groove is formed. Thus, the core element 12 can be inserted into the shell element 14 and secured relative to it, at least translationally.

[0031] In Figure 1 It can also be seen that rib-like projections 28 are provided on an outside of each fluid connection 16, 18, 20, which are designed to engage with an inner wall of a fluid line 22 pushed onto it.

[0032] Furthermore, it can be seen that the shell element 14 also has rib-like projections 30 on its inner surface facing each fluid connection 16, 18, 20. These rib-like projections 30 of the shell element 14 are designed to allow for the crimping of a respective press sleeve 32 (see Figure 3 ) to engage with an outer side of a respective fluid line 22. It should be added at this point that the complete fluid coupling 10 according to Figures 1 to 3 furthermore, it comprises another (not shown) shell element, which in the exemplary embodiment of the Figures 1 to 3The shell element 14 shown there is identical and, after the arrangement of the core element 12 in the shell element 14, is placed onto the core element 12 in an analogous manner such that the projections 24 of the further shell element engage with the recesses 26 of the core element 12. Subsequently, a press sleeve 32 is pushed onto a region 34 of the shell formed by the two shell elements in the area of ​​each fluid connection 16, 18, 20. A contact surface 36 is provided at the end of region 34 opposite each free end of the shell element 14 in the area of ​​a fluid connection 16, 18, 20, against which the corresponding press sleeve 32 can rest in a defined end position.In this final position, a locking lug 38, which is arranged on the free end of a shell element 14, engages with a longitudinal end of the crimp sleeve 32 to secure the crimp sleeve 32 against unintentional detachment from the shell elements 14. The crimp sleeve 32 has a substantially constant inner diameter from one longitudinal end to the other.

[0033] To enable or facilitate the crimping of a respective press sleeve 32 and thus the engagement of the respective area 34 of the shell element 14 with the fluid line 22, each area 34 of the shell element 14 is divided into resilient webs 40, which are separated from each other by slots 42. In this respect, Figure 1It can also be seen that the slots 42 penetrate the wall of the shell element 14 in a parallel manner, that is, the surfaces of the material of the shell element 14 bounding the slots 42 are aligned parallel to each other (see also Figure 2 ). This design of the slots 42 can enable the individual resilient webs 40 to be in contact with each other at least at their free ends when the fluid coupling 10 is compressed with a respective fluid line 22, meaning that the slots 42 are then closed there.

[0034] In Figure 2 It can also be seen that in an area 44, which extends between the areas 34 of the shell element 14, a bulge 46 is arranged, at which the wall of the shell element 14 extends radially outwards (in Figure 2 protrudes into the plane of the leaf). Figure 2In the illustrated embodiment, the wall thickness of the shell element 14 in the area of ​​the bulge 46 can remain essentially the same compared to adjacent sections of the area 44.

[0035] In Figure 3 The fluid coupling 10 according to the invention is shown as a side cross-sectional view in the unpressed state, but with a fluid line 22 arranged at the second fluid connection 18. Figure 3 , as well as in Figure 2It can be seen that the slots 42 extend from the free ends of the areas 34 of the shell element 14 through the contact surface 36 for the crimp sleeve 32 and that the slots 42 are directly adjacent to or terminate at a respective projection / stop for the fluid line 24. That is, in this embodiment, each projection 24 is located further away from the associated free end of the area 34 than the corresponding contact surface 36. In this way, a viewing window 48 is formed, which is not obstructed by the respective crimp sleeve 32, through which a user of the fluid coupling 10 can see whether the respective fluid line 22 has been inserted correctly up to the projection 24 or not.

Claims

1. Fluid coupling (10) which is configured to fluidically connect fluid lines (22) to each other, wherein the fluid coupling (10) comprises: - a first fluid connection (16) which is configured to be fluidically connected to a first of the fluid lines, - a second fluid connection (18) which is configured to be fluidically connected to a second of the fluid lines (22), and - at least two shell elements (14), wherein the fluid connections (16, 18, 20) are formed separately from each other, wherein the fluid connections (16, 18, 20) are fluidically connected to each other in order to fluidically connect the fluid lines (22) which are connected to the fluid coupling (10) to each other, wherein the fluid connections (16, 18, 20) are formed integrally on a common core element (12) of the fluid coupling (10), wherein the at least two shell elements (14) are configured to surround the core element (12) at each of the first and second fluid connections (16, 18) at the respective radial outer side thereof, characterized in that the fluid coupling (10) further comprises for each fluid connection (16, 18, 20) a pressing sleeve (32) which is configured to be received at a portion (34), which surrounds a respective fluid connection (16, 18, 20) radially at the outer side, of the at least two shell elements (14), wherein the respective pressing sleeve (32) is further configured to be plastically deformed in a radially inward direction in response to a force acting radially outwards on the pressing sleeve (32) so that a corresponding fluid line (22) is connected in a non-releasable non-destructive manner to the respective associated fluid connection (16, 18, 20), and wherein the at least two shell elements (14) in the region which is configured to receive a respective pressing sleeve (32) have a plurality of resilient webs (40), wherein the webs (40) in the mounted state of the fluid coupling (10) extend in particular parallel to each other.

2. Fluid coupling (10) according to claim 1, characterized in that the core element (12) has on the outer side thereof at least one recess (26), in particular at least two recesses (26), which is / are configured to engage with a matching projection (24) which protrudes from an inner side of at least one shell element (14).

3. Fluid coupling (10) according to the preceding claim, characterized in that the at least one recess (26) is in the form of a groove which extends completely around the outer side of the core element (12).

4. Fluid coupling (10) according to claim 2 or 3, characterized in that the projection (24) which is configured to engage with the associated recess (26) of the core element (12) in the mounted state of the fluid coupling (10) is formed to be divided in such a manner over the at least two shell elements (14) that the projection portions of the shell elements (14) in the mounted state of the fluid coupling (10) complement each other to form a projection (24) which extends substantially completely around the core element (12).

5. Fluid coupling (10) according to any one of the preceding claims, characterized in that each of the fluid connections (16, 18, 20) of the core element (12) has at the outer side thereof a plurality of rib-like protrusions (28) which are configured, in response to an arrangement of a fluid line (22) on the fluid connection (16, 18, 20) and a pressing of the pressing sleeve (32), to move into engagement with the fluid line (22) in order to secure it against extraction forces, and / or in that in a respective region (34) of the at least two shell elements (14), which surrounds a fluid connection (16, 18, 20) radially at the outer side, there is arranged on an inner side of the shell elements (14) a plurality of rib-like protrusions (30) which are configured, in response to an arrangement of a fluid line (22) on the fluid connection (16, 18, 20) and a pressing of the pressing sleeve (32), to move into engagement with the fluid line (22), in order to secure it against extraction forces.

6. Fluid coupling (10) according to any one of the preceding claims, where applicable according to claim 2 or claim 4, characterized in that on at least one of the shell elements (14) there is provided a stop (24) which is configured to limit pushing of a respective fluid line (22) onto a fluid connection (16, 18, 20), wherein in particular the stop (24) for the fluid line (22) on the projection (24) is formed for engagement with the core element (12), and / or in that on at least one of the shell elements (14) there is provided a contact face (36) which is configured to limit pushing of a respective pressing sleeve (32) onto the shell elements (14) in the mounted state of the fluid coupling (10), wherein in particular a spacing of the stop (24) for the fluid line (22) from an adjacent free end of the shell elements (14) in the mounted state of the fluid coupling (10) is greater than a spacing of the contact face (36) for the pressing sleeve (32) from the same free end of the shell elements (14).

7. Fluid coupling (10) according to any one of the preceding claims, characterized in that the at least two shell elements (14) comprise plastics material, in particular polybutylene terephthalate (PBT) and / or fibre-reinforced polymers, such as polyamide and / or polypropylene, and / or in that the core element (12) comprises plastics material, in particular polyoxymethylene (POM) or cross-linked polyethylene (PE-Xc).

8. Fluid coupling (10) according to any one of the preceding claims, characterized in that the at least two shell elements (14) are in the form of mutually identical shell elements (14).

9. Fluid coupling (10) according to any one of the preceding claims, characterized in that the at least two shell elements (14) are free from mutually compatible locking elements which are configured to secure the shell elements (14) to each other.

10. Fluid coupling (10) according to any one of the preceding claims, characterized in that the at least two shell elements (14) in the mounted state of the fluid coupling (10), with the exception of the regions (34) of the shell elements (14) which radially overlap the fluid connections (16, 18, 20) at the outer side, are formed to be substantially closed.

11. Fluid coupling (10) according to any one of the preceding claims, characterized in that a respective pressing sleeve (32) is in the form of a substantially cylindrical metal sleeve.

12. Fluid coupling (10) according to any one of the preceding claims, characterized in that a respective pressing sleeve (32) has a collar at least at one longitudinal end, in particular at both longitudinal ends.

13. Fluid coupling (10) according to any one of the preceding claims, characterized in that the at least two shell elements (14) have at the outer sides thereof in a region (44) which is arranged between the fluid connections (16, 18) a protuberance (46) extending radially outward.

14. Fluid coupling (10) according to any one of the preceding claims, characterized in that the webs (40) in the mounted state of the fluid coupling (10) extend parallel to each other.