FLUID CONNECTION UNIT

Description

[0001] The present invention relates to a fluid connection unit for connecting a fluid line to a fluid line connection. In the engine compartment of vehicles, for example, various components are connected to one another using rubber fluid lines. However, such rubber lines can have the disadvantage that they are not particularly resistant to external influences, such as mechanical stress. To prevent kinking of the rubber fluid lines, it is often necessary to manufacture the fluid lines in a pre-formed state according to their specific, predetermined intended use, i.e., to form bends in the fluid line during production. However, this severely limits the possible uses of a specific rubber fluid line, and it is necessary to produce a customized fluid line for each specific application using an associated special tool.

[0002] From document GB 2 032 030 A, which is considered the closest prior art, a fluid connection unit is known with an insert element having a projection with a locking flank configured to bear against a locking projection formed on the base body when the insert element is engaged with the receiving portion. Further reference is made to documents US 2016 / 369922 A1, IT MI20 121 068 A1, US 2020 / 248846 A1, and WO 2021 / 185419 A1, the latter being considered under Article 54(3) EPC.

[0003] It is therefore the object of the present invention to provide a fluid connection unit for connecting a fluid line to a fluid line connection, which also makes it possible to connect a corrugated pipe to an existing fluid line connection.

[0004] This object is achieved according to the present invention by a fluid connection unit according to claim 1.

[0005] It should be noted at this point that the "one axial end" of the base body and the "other axial end" of the base body represent two free ends of the fluid connection unit, which do not necessarily have to lie on the same axis.

[0006] A fluid line designed as a corrugated pipe can be connected to the connection piece of the base body, wherein the corrugated pipe does not have to consist exclusively of a sequence of wave troughs and wave crests, but can also comprise smooth sections, i.e. sections which have a substantially cylindrical shape over a predetermined area, and / or sections with increasing or decreasing diameter.

[0007] Advantageously, the insert element can have at least two, in particular at least four, radially outwardly projecting projections. A plurality of projections can have the advantage that sections of the base body can be arranged between the respective projections, viewed in a circumferential direction relative to an axis defined by the axial central connection opening, so that a rotational securing of the insert element relative to the base body can be achieved through engagement between the projections of the insert element and the base body.

[0008] The fluid connection unit according to the invention thus makes it possible to connect fluid lines, which are designed, for example, as corrugated pipes made of plastic, to existing components that are provided with a corresponding fluid line connection configured for connecting a rubber fluid line. The use of corrugated pipes as fluid lines can make it possible to produce cost-effective corrugated pipes that are straight in their main direction of extension and to provide the fluid lines with bends only during their respective use, depending on their intended purpose—i.e., to shape them into a desired fluid line path.

[0009] The two-part design of the insert element and the base body makes it possible to selectively connect the same base body to different insert elements that differ, for example, in the design of the axial central connection opening (e.g., different diameters), so that the fluid connection unit according to the invention can be configured for connection to differently designed fluid line connections. Because identically designed components of the fluid connection unit according to the invention can be used for different fluid line connections, the manufacturing costs of the fluid connection unit according to the invention can be significantly reduced.Of course, it is also conceivable that different base bodies fit a specific insert element, such as base bodies which differ in the design and / or orientation of the connecting piece, i.e. an angle which is formed between the connecting piece and the rest of the base body.

[0010] According to the present invention, the fluid connection unit further comprises a clamping element which is configured to engage with the receiving portion and, in a state engaged with the receiving portion, to exert a force on the at least one projection such that an inner wall defining the axial central connection opening of the insert element is preloaded radially inward. The clamping element can be substantially annular and made of an elastic material, in particular spring steel. By using the clamping element, a connection between the fluid connection unit and the fluid line connection can be reinforced, such that this connection can withstand higher pull-out forces, which are exerted, for example, due to a high fluid pressure of the fluid carried in the fluid line.

[0011] Here, too, it is possible for a base body or insert element to be connected to different clamping elements, which differ, for example, in their thickness and / or material (metal, plastic, etc.). This allows different clamping and holding forces to be achieved between the insert element and the fluid line connection.

[0012] In this case, it is conceivable both for the at least one projection of the insert element to project radially outwards in such a way that it can come into contact with the clamping element, which is formed substantially smooth at least on its inner side, and for the clamping element to have projections projecting radially inwards in such a way that they can contact the insert element when the insert element is connected to the receiving section.

[0013] The base body can further comprise a further receiving portion configured to be engaged by the clamping element in an initial position thereof. This means that the fluid connection unit according to the invention can have the clamping element connected to the further receiving portion in its delivery state. After connecting the fluid connection unit to the corresponding fluid line connection, the clamping element can be easily displaced from the further receiving portion to the receiving portion in order to come into contact with the at least one projection of the insert element.

[0014] Advantageously, the fluid connection unit can further comprise a code section containing a code, wherein the code is suitable for identifying a fluid connection unit. The code section, in particular, contains a code unique to a respective fluid connection unit and is advantageously a machine-readable code, in particular a DMC and / or an RFID element. Thus, for quality assurance purposes, each fluid connection unit can be recorded and its use documented.

[0015] In particular, it may be appropriate for the code section to be arranged in the region of the further receiving section in such a way that the code is superimposed radially on the outside by the clamping element when the clamping element is in the state in which it is engaged with the further receiving section. In this way, the clamping element can prevent the code section from being read out in the as-delivered state of the fluid connection unit or in the state in which the fluid connection unit is not yet fully connected to the fluid line connection, thereby preventing a fluid connection unit from being documented as assembled even though the corresponding connection has not yet been correctly established. In the case of an optically readable code section, the clamping element can prevent reading out by being made of a non-transparent material, such as metal.In the case of an electromagnetically readable code section, the clamping element can prevent reading by being made of a shielding material, such as a metal.

[0016] The code section can be formed separately from the base body and connectable to the base body, in particular using adhesive, printing, and / or a form-fitting connection, such as latching. It should be noted that the "separate design" of the code section is not limited to a design as a separate component, but, as already mentioned above, can also be realized by printing the fluid connection unit with a corresponding code.

[0017] To prevent the clamping element from inadvertently detaching from the further receiving section and thereby, for example, releasing the code section, a retaining projection can be arranged between the receiving section and the further receiving section, which protrudes radially outward from the base body in such a way that the clamping element is prevented from being displaced from engagement with the further receiving section towards engagement with the receiving section without changing the diameter of the clamping element. To also secure the clamping element in the opposite direction, i.e., a direction away from the receiving section, the base body can also have at least one radially outwardly protruding section, for example, an increase in the outer diameter of the base body.

[0018] In particular, the locking projection can be connected to the remaining base body via webs, wherein a minimum radial extension of the webs is less than a minimum radial extension of the remaining locking projection. In other words, the radially inner sides of the webs define a smaller inner diameter than a radially inner surface of the locking projection. For example, the locking projection can be substantially annular, and the webs can extend from a radially inner surface of the annular locking projection in an axial direction across the receiving portion toward the further receiving portion, in particular as far as the retaining projection.

[0019] If the insert element is designed such that its outer surface is in contact with the radially inner surfaces of the webs when the insert element is connected to the base body, an arcuate gap can result between two adjacent webs, viewed in a circumferential direction of the fluid connection unit. If the fluid connection unit is then pushed onto a fluid line connection, the elastic material of the insert element can deflect into a respective arcuate gap. This simplifies the sliding on of the fluid connection unit, particularly in the case where the fluid line connection is not completely cylindrical on its outer surface.

[0020] Furthermore, an inner wall of the axial central connection opening of the insert element can have a plurality of recesses, which are recessed radially outward from a nominal diameter of the axial central connection opening and which extend in an axial direction relative to the connection opening, at least in sections, along the inner wall of the axial central connection opening of the insert element. These recesses, which can also be referred to as grooves, can reduce a friction surface between the insert element and the fluid line connection, so that sliding the fluid connection unit according to the invention onto a respective fluid line connection can be facilitated.

[0021] In this case, a respective recess of the connection opening of the insert element can be assigned to a respective web of the base body in such a way that a web and a recess are aligned so as to overlap one another, viewed in a radial direction. In this way, a reduced wall thickness of the insert element, i.e., a respective recess, is arranged in the region of an inner side of the webs, so that the force required for a correct connection of the fluid connection unit according to the invention to a respective fluid line connection can be further reduced.

[0022] The plurality of recesses can extend from the axial end of the insert element, which is assigned to the locking projection of the base body, along the inner wall of the axial central connection opening of the insert element up to a maximum point which, in a radial direction, is just overlaid by the at least one projection. In particular, the recesses of the inner wall of the insert element can end such that at least a portion of the at least one projection of the insert element, viewed in a radial direction, overlaps a portion of the inner wall of the insert element which is substantially cylindrical, i.e., is free of the recesses of the inner wall (grooves) over its entire circumference in the circumferential direction. This can ensure that the insert element, optionally in cooperation with the clamping element, can establish a sealing engagement with the fluid line connection.

[0023] Advantageously, the inner wall of the axial central connection opening of the insert element can have a circumferential groove. This groove can, for example, be designed as a counter-shape to a so-called "olive." Such an "olive" is a circumferential projection formed on the outside of a fluid line connection in the region of its free end.

[0024] This groove can be spaced apart from the plurality of recesses. This means that the recesses in the inner wall of the insert element do not extend to the groove, allowing large-area contact between the groove and the corresponding portion of the fluid line connection (e.g., the "olive").

[0025] Adjacent to the groove, in particular in a region between the groove and the end of the recesses, at least one sealing lip can be arranged, which protrudes circumferentially from the inner wall of the insert element radially inwards, advantageously obliquely.

[0026] The fluid connection unit may further comprise a sleeve unit configured to be arranged radially outside the connecting piece and to secure a connection of the connecting piece to the fluid line. The sleeve unit may reinforce and secure engagement of the fluid line with the connecting piece by reducing its diameter, for example, by shrinking or pressing.

[0027] In an advantageous embodiment, the at least one projection of the insert element can protrude further radially outward in the region of the receiving section than the base body. This means that the webs connecting the locking projection to the rest of the base body protrude less radially outward here, when viewed in the circumferential direction of the receiving section, than the projections of the insert element. As already mentioned above, an inner side of the clamping element can thus be designed to be substantially smooth.

[0028] Furthermore, pressure clamps can be provided on the projections of the insert element, wherein in particular a pressure clamp can be assigned to each projection. Preferably, a pressure clamp completely overlaps a projection radially outward. A pressure clamp can have a base section, which extends in the axial direction of the insert element and along the circumferential direction of the insert element, and two side sections, wherein the side sections extend in the axial direction of the insert element and essentially radially inward. The pressure clamps can thus be designed in particular in a U-shape. A respective side section can in particular engage with an undercut of a projection, for example with flanks of the projection that run essentially radially inward. In this case, a pressure clamp can enclose a respective projection at least partially or even completely.Alternatively or additionally, the pressure clips can be glued to the projections.

[0029] The pressure clamps can, for example, be attached to the projections after the insert element has been mounted on the base body and before a fluid connection is inserted into the insert element. By attaching the pressure clamps, in particular the outer diameter of the insert element of the fluid connection unit or of the projections thereof can be enlarged, whereby the clamping element can exert an increased contact force on the fluid connection inside the insert element. For this purpose, it can be advantageous for the pressure clamps to be made of a material that is stiffer than the material of the insert element, for example polyamide 6 or polypropylene or metal. Furthermore, by attaching the stiffer pressure clamps, it can be prevented that the clamping element contactes the webs of the base body during elastic deformation of the insert element and transmits force to them.Thus, the restoring force of the clamping element can be used essentially entirely as a contact force on the fluid connection.

[0030] It is also conceivable, instead of using the pressure clamps, to manufacture the insert element using a multi-component injection molding process such that, in particular, each projection of the insert element can comprise a section of softer material and a section of stiffer material. For example, a projection can comprise a stiffer material radially outward and a softer material radially inward.

[0031] The present invention will be described in more detail below using an exemplary embodiment with reference to the accompanying drawings. It shows: Figure 1 is an exploded view of a first embodiment of a fluid connection unit according to the invention; Figure 2 is a perspective view of the first embodiment of the fluid connection unit according to Figure 1 in an assembled state; Figure 3 shows a side cross-sectional view of the first embodiment of the fluid connection unit; Figure 4 shows a side view of a second embodiment of a fluid connection unit according to the invention; Figure 5 shows a cross-sectional view of the second embodiment of the fluid connection unit according to the invention along the section line VV from Figure 4 and Figure 6 shows a cross-sectional view of a third embodiment of a fluid connection unit according to the invention along the section line VI-VI of Figure 4 .

[0032] In Figure 1 A fluid connection unit according to the invention is generally designated by the reference numeral 10. The fluid connection unit 10 comprises a base body 12, which is Figure 1end shown on the right comprises a connecting piece 14 to connect the base body 12 with a (in Figure 1 not shown) fluid line. On the connecting piece 14, a receiving groove 16 is arranged, which is designed to receive a sealing element 18 (see Figure 2 ) to seal against the fluid line.

[0033] The base body 12 comprises a receiving section 20 and a further receiving section 22, between which a retaining projection 24 is arranged, the radially outward extension of which is greater than that of the receiving section 20 or the further receiving section 22. In the embodiment shown here, four webs 26 are arranged in the receiving section 20, which connect the retaining projection 24 to a locking projection 28. It can be seen that the webs 26 are connected to the substantially annular locking projection 28 on a radially inner surface thereof, i.e., they protrude further radially inward than the locking projection 28.

[0034] In the area of ​​the further receiving section 22, a receiving surface 30 is provided, which is designed to be connected to a code section 32. A code is arranged on the code section 32, which can be read, for example, using an electronic reader.

[0035] In the illustrated embodiment, the fluid connection unit 10 further comprises a clamping element 34, which is designed here as an annular, resilient clamp. In the as-delivered state of the fluid connection unit 10 according to the invention, the clamping element 34 can be connected to the additional receiving section and held in place there by the retaining projection 24 and an enlargement of the outer diameter 36 of the base body 12. In this position, the clamping element 34 can cover / shield the code section 32 in such a way that it cannot be read.

[0036] Furthermore, the fluid connection unit 10 according to the invention comprises an insert element 38, which is made of an elastic material, namely rubber. The insert element 38 has projections 40 on its outer circumference, which project radially outward and are dimensioned such that they can engage in openings 42 formed in the receiving section 20 of the base body 12 between adjacent webs 26.

[0037] The insert element 38 has an axial central connection opening 44, which is designed to receive a fluid connection. On an inner wall of the insert element 38, which defines the axial central connection opening 44, a plurality of recesses 46 are arranged distributed in the circumferential direction, which are recessed radially outwardly from a nominal diameter of the axial central connection opening 44 and which extend in a groove-like manner from the Figure 1the left end of the insert element 38 extend in an axial direction, that is to say a direction substantially parallel to an axis X defined by the axial central connection opening 44 (see Figure 3 ).

[0038] As in Figure 2 As can be seen, the insert element 38 is rotationally secured and aligned relative to the base body 12 by the engagement of the projections 40 with the webs 26 of the base body 12 in such a way that a recess 46 is assigned radially inward to each web 26.

[0039] If the fluid connection unit 10 is pushed onto a corresponding fluid line connection, the elastic material of the insert element 38 can escape into an arcuate free space, which is left free on an inner side of the locking projection 28 between two respective adjacent webs 26, in particular when displacing it over a so-called "olive" of the fluid line connection.

[0040] In Figure 3 It can also be seen that the projections 40 of the insert element 38 have a locking flank 48 on a side facing the locking projection 28, which, in particular when the fluid connection unit 10 is connected to a respective fluid line connection, prevents the insert element 38 from becoming detached from the base body 12 through contact with the locking projection 28. On a side opposite the locking projection 28, the projections 40 of the insert element 38 have insertion flanks 50, which facilitate connecting the insert element 38 to the base body 12.

[0041] It is in Figure 3 It can also be seen that the groove-like recesses 46 still end in a region of the insert element 38 which is overlaid in a radial direction by the projections 40.

[0042] Furthermore, a groove 52 is arranged on the inner wall of the axial central connection opening 44 of the insert element 38, which groove is designed and constructed to engage with the "olive" of a fluid line connection.

[0043] In the area of ​​the connecting piece 14 of the base body 12, a sleeve unit 54 is arranged radially outwardly, which can secure a connection of the connecting piece 14 to the fluid line 56, for example by pressing.

[0044] In Figure 4 A second embodiment 10' of a fluid connection unit according to the invention is shown, which differs from the first embodiment 10 only in that the connecting piece 14 of the base body 12' is arranged thereon, forming an angle. Furthermore, it should be explicitly noted that all features, effects, and advantages of the first embodiment 10 can also be applied to the second embodiment 10', and vice versa.

[0045] As in Figure 4 indicated by the line VV, is in Figure 5 a sectional view through the receiving section 20 including the associated insert element 38 is shown. In Figure 5 It can be clearly seen that the projections 40 of the insert element 38 protrude further radially outwards than a maximum radial extension of the webs 26 of the base body 12 or 12'.

[0046] If the clamping element 34 is connected to the receiving section 20 after the fluid connection unit 10 or 10' has been completely connected to a respective fluid line connection, the resilient restoring force of the clamping element 34 exerts a force on the projections 40 of the insert element 38 such that the elastic material of the insert element 38 is urged radially inward and pressed onto the fluid line connection.

[0047] Furthermore, in Figure 6a third embodiment 10" of a fluid connection unit according to the invention is illustrated in a cross-sectional view. Analogous to the embodiment shown in Figure 5 In the sectional view of the second embodiment 10' shown in Figure 6 shown cross-section along the same section line Figure 4 . The line of sight is in Figure 6 but opposite to the direction of view Figure 5, namely in the direction of the connection opening 44 of the insert element 38. The third embodiment 10" of the fluid connection unit according to the invention differs from the first embodiment 10 and the second embodiment 10' only in that pressure clamps 58 are provided on the projections 40 of the insert element 38. In particular, a pressure clamp 58 is assigned to each projection 40. Furthermore, it should be explicitly pointed out that all features, effects and advantages of the first embodiment 10 and / or the second embodiment 10' can also be applied to the third embodiment 10", and vice versa.

[0048] A respective projection 40 is preferably completely overlapped radially outwardly by a pressure clamp 58. Furthermore, the pressure clamps 58 each have two radially inwardly extending side sections 60, which are designed to prevent the pressure clamp 58 from becoming detached from a respective projection 40. In this case, the pressure clamps 58 can be arranged in the Figure 6In the illustrated state, they generate a clamping force due to which the pressure clamps 58 can be firmly held on the projections 40. Alternatively or additionally, the pressure clamps 58 can be glued to the projections 40. The pressure clamps 58 can be substantially U-shaped, wherein a respective base section 62 of a pressure clamp 58 extends in the circumferential direction and the two side sections 60 of a pressure clamp 58, as legs of the U-shape, are arranged substantially at right angles to the base section 62, in particular extending radially inward. The free ends of the two side sections 60 of a pressure clamp 58 are spaced apart from one another, in particular in the circumferential direction, by a smaller distance than the maximum extension of a respective projection 40, viewed in the circumferential direction.

[0049] By attaching the pressure clamps 58, the embodiment 10" of the fluid connection unit has an increased outer diameter in the area of ​​the insert element 38 compared to the embodiments 10 and 10'. The pressure clamps 58 can in particular be made of a plastic that is stiffer than the material of the insert element 38, preferably polyamide 6 or polypropylene. If the fluid connection unit 10" is now in a state connected to a fluid connection, the resilient restoring force of the clamping element 34 (in Figure 6 not shown) exerts a force on the pressure clamps 58, which force is transferred from the pressure clamps 58 to the projections 40. Due to the increased outer diameter in the region of the insert element 38, the elastic material of the insert element 38 can be pushed further radially inward via the clamping element 34, and an increased contact force on the fluid connection can be generated.

[0050] Furthermore, by designing the radial extent of the side sections 60 of a pressure clamp 58, a distance between a respective free end of a side section 60 and an intermediate region 64 of the insert element 38 can be adjusted. This makes it possible to define the point at which a pressure clamp 58 is displaced radially inward until it strikes the intermediate region 64 of the insert element 38, i.e., comes into contact with it, whereby the restoring force of the clamping element 34 can then be transmitted to the insert element 38 via both the base section 62 and the side sections 60 of the pressure clamp 58. Furthermore, the U-shaped arrangement of the pressure clamps 58 can reduce the deformation of the elastic material of the insert element 38 in the circumferential direction.Overall, this can prevent the clamping element 34 from contacting the webs 26 during the elastic deformation of the insert element 38 and from transmitting force to these instead of to the insert element 38.

[0051] The attachment of the pressure clamps 58 to the projections 40 can be carried out by the side sections 60, which may initially be less bent with respect to the base section 62, only after contacting a projection 40 by a respective pressure clamp 58 in the Figure 6 shown state, wherein a respective side portion 60 can be bent in the direction of an undercut of a projection 40. Alternatively, the pressure clamps 58 can be manufactured in a U-shaped state and subsequently pressed onto the projections 40, wherein a higher elasticity of the material of the insert element 38 compared to the material of the pressure clamps 58 can be advantageous.

[0052] At this point, it should be noted that instead of subsequently attaching the pressure clamps 58 to the projections 40, it is also conceivable to manufacture the insert element 38 using a multi-component injection molding process, wherein, in particular, a projection 40 may comprise a section of softer material and a section of stiffer material. For example, a respective projection 40 may comprise a stiffer material radially outward and a softer material radially inward.

Claims

1. Fluid connection unit (10, 10', 10") for connecting a fluid line (56) to a fluid line connection of a higher-level assembly not belonging to the invention, comprising a base body (12, 12') which has a connection piece (14) at one axial end for connection to the fluid line (56) and which has a receiving section (20) at the other axial end, an insert element (38) comprising an elastic material consisting of rubber, having at least one projection (40) projecting radially outwards and defining an axial central connection opening (44) in its interior, wherein the insert element (38) is manufactured separately from the base body (12, 12') and can be connected to the base body (12, 12') in such a way that the at least one projection (40) projects into a respective corresponding opening (42) formed in the region of the receiving section (20), and wherein the at least one projection (40) has a blocking flank (48) which, together with the associated projection (40), extends in a substantially radial direction outwards and faces the axial end of the base body (12, 12') which is opposite the connection piece (14), wherein the blocking flank (48) is designed, in a state in which the insert element (38) is engaged with the receiving section (20), to bear against a blocking projection (28) which is formed on the base body (12, 12'). characterised in that the fluid connection unit (10, 10', 10") further comprises a clamping element (34) which is designed to engage with the receiving section (20) and, to exert force on the at least one projection (40) in a state of engagement with the receiving section (20) in such a way that an inner wall defining the axial central connection opening (44) of the insert element (38) is preloaded radially inwards.

2. Fluid connection unit (10, 10', 10") according to claim 1, characterised in that the base body (12, 12') further comprises a further receiving section (22) which is designed to be engaged by the clamping element (34) in an initial position thereof.

3. Fluid connection unit (10, 10', 10") according to any one of the preceding claims, characterised in that the fluid connection unit (10, 10', 10') further comprises a code section (32) containing a code, wherein the code is suitable for identifying a fluid connection unit (10, 10', 10'), wherein the code section (32) in particular contains a code that is unique for a respective fluid connection unit (10, 10', 10') and is advantageously a machine-readable code, in particular a DMC and / or an RFID element.

4. Fluid connection unit (10, 10', 10") according to any of the preceding claims 2 or 3, characterised in that the code section (32) is arranged in the region of the further receiving section (22) in such a way that, when the clamping element (34) is engaged with the further receiving section (22), the code is radially superimposed on the clamping element (34) on the outside.

5. Fluid connection unit (10, 10', 10") according to any of the preceding claims 3 or 4, characterised in that the code section (32) is formed separately from the base body (12, 12') and can be connected to the base body (12, 12'), in particular by means of adhesive bonding, printing and / or a form-fitting connection, such as locking.

6. Fluid connection unit (10, 10', 10") according to any one of the preceding claims, insofar as dependent on claim 2 characterised in that a retaining projection (24) is arranged between the receiving section (20) and the further receiving section (22), which protrudes radially outwards from the base body (12, 12') in such a way that the clamping element (34) is prevented from being displaced out of engagement with the further receiving section (22) in the direction of engagement with the receiving section (20) without changing the diameter of the clamping element (34).

7. Fluid connection unit (10, 10', 10") according to any one of the preceding claims, characterised in that the locking projection (28) is connected to the remaining base body (12, 12') via bridges (26), wherein a minimum radial extension of the bridges (26) is less than a minimum radial extension of the remaining locking projection (28).

8. Fluid connection unit (10, 10', 10") according to any one of the preceding claims, characterised in that an inner wall of the axial central connection opening (44) of the insert element (38) has a plurality of recesses (46) which are recessed radially outwardly from a nominal diameter of the axial central connection opening (44) and which extend in an axial direction relative to the connection opening (44) at least in sections along the inner wall of the axial central connection opening (44) of the insert element (38).

9. Fluid connection unit (10, 10', 10") according to any of the preceding claims 7 or 8, characterised in that a respective recess (46) of the connection opening (44) of the insert element (38) is assigned to a respective bridge (26) of the base body (12, 12') in such a way that a bridge (26) and a recess (46), viewed in a radial direction, are aligned so as to overlap each other.

10. Fluid connection unit (10, 10', 10") according to claim 8 or 9, characterised in that the majority of recesses (46) extend from the axial end of the insert element (38) which is assigned to the locking projection (28) of the base body (12, 12'), extend along the inner wall of the axial central connection opening (44) of the insert element (38) to a maximum point, which in a radial direction, is just superimposed by the at least one projection (40).

11. Fluid connection unit (10, 10', 10") according to any one of the preceding claims, characterised in that the inner wall of the axial central connection opening (44) of the insert element (38) has a groove (52) running in the circumferential direction.

12. Fluid connection unit (10, 10', 10") according to claim 11 or any of the preceding claims 8 to 10, characterised in that the groove (52) is spaced apart from the plurality of recesses (46).

13. Fluid connection unit (10, 10', 10") according to any one of the preceding claims, characterised in that the fluid connection unit (10, 10', 10") further comprises a sleeve unit (54) which is designed to be arranged radially outside the connection piece (14) and to secure a connection between the connection piece (14) and the fluid line (56).

14. Fluid connection unit (10, 10', 10") according to any one of the preceding claims, characterised in that the at least one projection (40) of the insert element (38) in the region of the receiving section (20) projects further radially outwards than the base body (12, 12').