Holding device, plug connection arrangement and cable system

Abstract

The invention relates to a holding device (16) comprising a C-shaped support section (17). The support section (17) is provided in a plug-in connection arrangement (7) for placement on the outer circumference of a connecting piece (3) and subsequently for gripping the outer circumference of the connecting piece (3). The support section (17) forms, at least partially, a support surface oriented in an axial direction, against which, in the plug-in connection arrangement (7), the holding device (16) is axially supported by the connecting piece (3) after gripping the outer circumference. Furthermore, at least one holding section (34, 35, 36) is provided, each extending axially from the support section (17).The at least one retaining section (34, 35, 36) extends inwards with one end facing away from the support section (17) transversely to the axial direction, wherein one end of each is provided in the plug connection arrangement (7) for gripping behind the pipe (2) after gripping the outer circumference of the connecting piece (3) and in the inserted state of a pipe end of a pipe (2).

Description

[0001] The invention relates to a holding device designed to prevent a pipe end inserted into a receiving opening of a connecting piece in a plug-in connection arrangement from migrating out of the receiving opening by means of a positive locking mechanism. The holding device comprises a support section that is C-shaped, wherein the support section is designed to rest on the outer circumference of the connecting piece in the plug-in connection arrangement and subsequently to grip the outer circumference of the connecting piece. The support section forms, at least partially, a support surface oriented in an axial direction, against which the holding device is axially supported by the connecting piece after gripping the outer circumference. The invention further relates to a plug-in connection arrangement and a piping system.

[0002] To secure pipes to connection fittings in piping systems, push-fit connections are sometimes used. In these connections, one end of the pipe is prevented from unintentionally slipping out after being inserted into a corresponding opening in the connection fitting. Often, a separate retaining device is provided, which usually prevents the pipe from slipping out by means of a positive locking mechanism.

[0003] WO 2005 / 045299 A1 discloses a push-fit connection arrangement in which a pipe is inserted with one end into a receiving opening of a connecting piece and, in this position, is positively prevented from unintentionally migrating out by a retaining device. For this purpose, the retaining device is positioned in a fastening position in which it engages the connecting piece with a C-shaped support section. Sections of the support section engage in recesses of the connecting piece, thus holding the retaining device in place by bearing against support shoulders defined by the recesses. Furthermore, sections of the retaining device extend into an interior space of the connecting piece and engage behind a shoulder of the inserted pipe end.This holds the pipe end inside the connection fitting in a position where the pipe end rests against a seal that is also included in the connection fitting.

[0004] Starting from the prior art described above, the object of the present invention is to create a holding device for a plug connection arrangement, wherein this holding device should enable a positive locking fixation of a pipe end in a connecting piece in a reliable and at the same time as compact a manner as possible.

[0005] This problem is solved starting from the preamble of claim 1 in conjunction with its characterizing features. The subsequent dependent claims each describe advantageous embodiments of the invention. A plug-in connection arrangement in which a holding device according to the invention is used is further the subject of claims 8 to 13. In addition, claims 14 and 15 each relate to a piping system for a hydraulic supply system.

[0006] According to the invention, a holding device, which is designed to prevent a pipe end inserted into a receiving opening of a connecting piece in a plug-in connection arrangement from migrating out of the receiving opening by means of a positive locking mechanism, comprises a support section which is C-shaped. The support section is designed in the plug-in connection arrangement to rest on and subsequently engage the outer circumference of the connecting piece, wherein the support section forms at least a portion of an axially oriented support surface against which the holding device is axially supported by the connecting piece in the plug-in connection arrangement.

[0007] The holding device according to the invention is thus designed to positively connect a pipe end and a connecting piece in a push-fit connection arrangement, in order to prevent the pipe end from migrating out of a receiving opening of the connecting piece. The holding device is designed to be placed on the outer circumference of the connecting piece to create this push-fit connection arrangement, whereby this placement is to be carried out on a support section which, in the holding device according to the invention, is C-shaped. Due to this design, when using the holding device according to the invention in a push-fit connection arrangement, the outer circumference of the connecting piece can be placed on this support section and subsequently gripped.

[0008] The support section of the holding device according to the invention is therefore designed in a C-shaped profile, so that the support section has at least a substantially curved shape with two free ends that form an opening between them. The outer circumference of the connecting piece is placed onto and gripped via this opening. Preferably, the support section is designed in the shape of an annular segment and serves to be placed onto the connecting piece, which is cylindrical at least in the area of ​​placement.

[0009] In addition to its function of positioning and gripping, the support section of the holding device according to the invention also serves to support the holding device against the connecting piece when used in a plug-in connection arrangement. For this purpose, the support section forms a support surface, at least in certain sections, which is oriented in an axial direction. After the outer circumference is positioned and gripped, contact is established between this support surface and the connecting piece. This results in axial support of the holding device against the connecting piece in the plug-in connection arrangement.

[0010] In the context of the holding device according to the invention, "axial" refers to an orientation in a longitudinal direction, which also corresponds to a depth direction of the C-shaped support section. In this respect, the support surface is formed, at least partially, on an axial end face of the C-shaped support section.

[0011] The invention now comprises the technical teaching that at least one retaining section is provided, which extends axially from the support section. The retaining section extends inwards with one end facing away from the support section, transversely to the axial direction, and each end is provided for engagement from behind on the side of the pipe in the plug-in connection arrangement after the outer circumference of the connecting piece has been gripped and the pipe end has been inserted.

[0012] In other words, the holding device according to the invention has at least one holding section which extends from the support section in the axial direction in which the support surface of the support section is also oriented. With one end facing away from the respective connection to the support section, the at least one holding section is guided transversely to the axial direction inwards, thus orienting itself with one end towards an inner region of the C-shaped support section. When the holding device is used in the plug-in connection arrangement, one end of each holding section is designed to allow the pipe to grip behind it.

[0013] This allows for the construction of a holding device which, in a plug-in connection arrangement, provides a reliable, positive-locking fixation of the pipe end in its inserted state within the receiving opening of the connecting piece. Due to the design of the holding device, it can, on the one hand, be supported by its support section on the connecting piece and grip it, and on the other hand, engage the pipe behind it via the at least one holding section, thus connecting the pipe end to the connecting piece in the inserted state. On the other hand, this fixation can be achieved in a compact manner with respect to the pipe in the radial direction by first connecting the at least one holding section axially to the support section and then extending inwards at one end perpendicular to this axial direction.Thus, the holding device according to the invention is designed to extend from the encompassed area of ​​the connecting piece beyond a connection end at which the receiving opening of the connecting piece opens and to engage behind the pipe there.

[0014] According to the invention, the at least one retaining section extends from the support section in the axial direction in which the support surface for bracing the retaining device on the connecting piece is also oriented. Thus, when the retaining device is used in a plug-in connection arrangement, the at least one retaining section extends, with respect to the connecting piece, from the area where the retaining device is mounted with the support section, towards the connection end where the receiving opening of the connecting piece opens and where the pipe is inserted into the connecting piece with its pipe end. With one end of each retaining section, which is directed inwards transversely to the axial direction, the at least one retaining section can then engage behind the pipe beyond the connection end of the connecting piece.

[0015] Preferably, the at least one retaining section is extended with one end transversely to the axial direction so far inwards that the end overlaps with an inner area formed by the C-shape of the support section. As a result, even when the retaining device is installed in the plug-in connection arrangement, the at least one retaining section projects radially with one end towards the receiving opening of the connector.

[0016] The holding device according to the invention is in particular designed as a single piece, so that the holding device consists of a piece forming the support section and the at least one holding section. Preferably, the holding device is made of a metallic material.

[0017] According to one embodiment of the invention, the support section comprises several segments that together define a first inner diameter of the C-shaped support section and whose end faces each form part of the support surface. Adjacent segments are connected to one another via an intermediate segment, on which at least one retaining section projects and which rests on a second inner diameter of the support section that is larger than the first inner diameter. Such a design of the retaining device has the advantage that a sufficiently large support surface can be formed via the segments to achieve axial support of the retaining device from the connecting piece.Since the at least one retaining section extends from the one segment which, compared to the segments defining the first inner diameter, lies on a larger, second inner diameter of the support section, the at least one retaining section can also be easily guided outside the connecting stub towards the pipe.

[0018] In a further development of the aforementioned embodiment, the free ends of the C-shape of the support section are also designed to curve outwards transversely to the axial direction. This advantageously simplifies the placement of the support section onto the connecting piece.

[0019] The support section is particularly preferably designed to be resilient and can be elastically expanded at the free ends of its C-shape. This allows the support section to expand elastically for insertion and gripping, so that its circumferential extent can be designed such that, when inserted, the support section easily encloses a significant portion of the outer circumference of the connecting piece. This ensures that the holding device remains reliably on the connecting piece. This variant is particularly well-suited for combination with the previous embodiment, in which the free ends are bent outwards transversely to the axial direction, as this simplifies the elastic expansion during insertion.

[0020] According to one embodiment of the invention, the at least one retaining section is connected to the support section by a first subsection, which extends axially from the support section and transitions into a second subsection. Furthermore, each second subsection extends inward from each first subsection, curved transversely to the axial direction, and transitions there into a third subsection, which extends transversely to the axial direction and forms one end of each. This allows for a suitable path for the at least one retaining section to be realized for gripping behind the pipe. Preferably, each third subsection is set back with respect to the axial extension of each second subsection in the direction of each first subsection.

[0021] In one embodiment of the invention, the at least one retaining section is designed to be resilient and can be elastically deflected outwards at one end transversely to the axial direction. This has the advantage that the at least one retaining section can be elastically moved to engage behind the pipe. In particular, this variant is combined with the resilient design of the support section, whereby the retaining device according to the invention is designed as a retaining clamp or clip, which, when placed in the fastening position, is clamped firmly on both the connecting piece and the pipe, thereby creating a positive-locking connection between the pipe and the connecting piece.

[0022] Particularly preferred in the holding device according to the invention are several holding sections, each of which connects to the C-shaped support section at circumferential intervals. Advantageously, this also allows the pipe to be engaged behind several sections of the holding device, so that, in the plug-in connection arrangement, reliable contact between the holding device and the pipe is established and the load is distributed across the several sections. The holding sections can have different extensions in the circumferential direction of the C-shaped support section or be designed with identical extensions.

[0023] The invention further relates to a plug-in connection arrangement in which a pipe is inserted with one pipe end into a receiving opening in an insertion direction, which, in the case of a connecting piece, opens at its connecting end. In addition, a retaining device according to one or more of the variants described above is provided, wherein this retaining device can be positioned in a fastening position in which the retaining device, with its support section, is placed on an outer circumference of the connecting piece and positively prevents the pipe end inserted into the receiving opening from migrating out of the receiving opening.In its fastening position, the holding device is supported on one side by its support section on a support shoulder, which is defined on the outer circumference of the connection stub pointing in the insertion direction, while on the other hand the holding device engages behind a shoulder with its at least one holding section on the side of the pipe, which is designed on the pipe pointing in the opposite direction of insertion.

[0024] The push-fit connection arrangement thus serves to fix the end of a pipe in the receiving opening of a connecting piece. For this fixing, a retaining device according to the invention is used within the push-fit connection arrangement, which prevents the pipe end from unintentionally migrating out of the receiving opening by means of a positive locking mechanism. Within the push-fit connection arrangement, the retaining device is supported on one side by a support shoulder on the connecting piece and engages behind a shoulder on the other side. The support shoulder is designed to point in the insertion direction of the pipe end into the receiving opening, while the shoulder is defined to point in the opposite direction. Thus, the retaining device holds the pipe end in its inserted state in the receiving opening by means of the support and engagement.

[0025] In the push-fit connection arrangement, the connecting piece forms a connection for the pipe, for which purpose the connecting piece is provided with a receiving opening. The receiving opening opens at one end of the connecting piece, so that, when the pipe end is inserted, the receiving opening is spatially connected to an interior region of the pipe. Preferably, the receiving opening forms at least part of a conduit that, when the pipe end is inserted, can exchange fluid, i.e., gas or liquid, with the pipe. Within the scope of the invention, the connecting piece can be configured on a component to which the fluid is supplied via the pipe. Preferably, the connecting piece is a pipe section and, in addition to a cylindrical inner bore that defines the receiving opening, also has at least a substantially cylindrical outer contour.

[0026] The tube is preferably designed as a cylindrical tube, at least at its end, thus having a cylindrical outer contour in addition to a cylindrical inner bore. Within the scope of the invention, the tube can be designed as a single piece, but preferably it is composed of several parts, one of which forms the tube end. Most preferably, this part also defines a space that connects the tube ends and is open on one side, with the other part then closing this open side of the space by resting on top of the first part.

[0027] One possible embodiment of the plug-in connection arrangement is that the support shoulder is defined by a circumferential collar, wherein the at least one retaining section, in the mounting position of the retaining device, extends past the collar on the outside to the connection end of the connecting piece. Particularly preferably, the circumferential collar is formed by a groove with which the connecting piece is provided around its outer circumference and into which the retaining device, in its mounting position, is inserted with its support section.

[0028] Alternatively, but preferably in addition to the aforementioned embodiment, an embodiment of the plug-in connection arrangement is characterized by the shoulder defining a corresponding support area for each end of the at least one retaining section of the retaining device. In particular, each support area is defined by targeted material recesses or formed by material accumulations away from the support area. This allows for a clear orientation of the shoulder, and thus also of the rotor, relative to the retaining device, thereby simplifying the assembly of the plug-in connection arrangement. If the retaining device according to the invention also has several retaining sections, which are designed with different widths in the circumferential direction of the support section, a clear mounting position of the shoulder relative to the retaining device can also be defined by appropriately designing the corresponding support areas.

[0029] Preferably, the mounting of the holding device with its support section onto the outer circumference of the connecting piece takes place in a mounting direction oriented transversely to the insertion direction. The corresponding support areas on the shoulder are designed as pockets, each open in the opposite direction to the mounting direction. This ensures that, both when the holding device with its support section is mounted onto the outer circumference of the connecting piece and when the pipe end is inserted into the receiving opening, each individual mounting section of the holding device is inserted into its respective pocket by the pipe. This has the advantage of ensuring that the pipe and the holding device are correctly aligned with each other.

[0030] In a further development of the invention, each individual pocket is also limited on both sides in the circumferential direction of the heel, whereby a rotation protection is also achieved through the interaction of the heel and the holding device.

[0031] The invention further relates to a piping system for a hydraulic supply system, wherein this hydraulic supply system is in particular a supply system for an electrically driven vehicle drive axle. The piping system comprises at least one pipe, which is attached at at least one pipe end to an associated connecting piece in a plug-in connection arrangement, implemented according to one or more of the variants described above. The at least one pipe can be attached at each of its two pipe ends via such a plug-in connection arrangement.

[0032] Preferably, at least one pipe is attached at one end to a corresponding connection fitting via the push-fit connection arrangement, while the other end of at least one pipe is inserted into another corresponding connection fitting without any fastening. This is because the push-fit connection arrangement allows the corresponding pipe end to be easily held in place by the holding device according to the invention, thus reliably preventing the other, unsecured pipe end from slipping out. For this purpose, a sufficient insertion depth is preferably achieved at the unsecured pipe end.

[0033] An advantageous embodiment of the invention, which is explained below, is illustrated in the drawings. It shows: Fig. 1 a perspective view in the area of ​​a piping system with a plug connection arrangement according to the invention; Fig. 2 a sectional view in the area of ​​the plug connection arrangement from Fig. 1; Fig. 3 another sectional view in the area of ​​the plug connection arrangement Fig. 1; and Fig. 4 a perspective view of a holding device of the plug connection arrangement from the Fig. 1 to 3, according to a preferred embodiment of the invention.

[0034] Out of Fig. Figure 1 shows a perspective view of a portion of a piping system 1, which is part of a hydraulic supply system for an electrically driven vehicle drive axle. This hydraulic supply system is designed to supply components of the vehicle drive axle with hydraulic fluid, in particular oil. The piping system 1 is shown in the area of ​​a pipe 2, through which a connection is established between two connection points in the form of connection ports 3 and 4 within the hydraulic supply system. Connection port 3 specifically represents the connection of a heat exchanger of the hydraulic supply system.

[0035] The pipe 2 is inserted into the piping system 1 with each pipe end 5 or 6 into the respective connection fitting 3 or 4, wherein the pipe end 6 is merely inserted into the connection fitting 4, while the connection fitting 3 provides a fixation of the inserted pipe end 5 in a plug connection arrangement 7, which is implemented here according to a preferred embodiment of the invention.

[0036] The piping system 1 is located in the Fig. 2 and Fig. 3 each shown in section in the area of ​​the plug connection arrangement 7, wherein in particular in Fig. As can be seen in Figure 2, the pipe 2 is inserted with its pipe end 5 into a receiving opening 8, which opens at the connection fitting 3 at its connection end 9 and which is designed as a receiving bore. As can also be seen in particular from Fig. As can be seen from Figure 2, the pipe 2 is designed in multiple parts, with the pipe ends 5 and 6 each being formed on a first part 10, to which a second, lid-like part 11 is attached. The first part 10 and the second part 11 of the pipe 2 together define a conduit volume of the pipe 2 connecting the pipe ends 5 and 6.

[0037] Part 10 of the tube 2 forms the tube end 5 as a hollow cylindrical thickening 12, with which the tube 2 is inserted into the receiving opening 8 and in whose outer surface a circumferential groove 13 is also provided. A sealing ring 14 is received in this groove 13, which bears against both a groove base and an inner wall of the receiving opening 8, thereby sealing any gap between the receiving opening 8 and the tube end 5. The insertion depth of the tube end 5 into the receiving opening 8 is limited by a stop 15 on the receiving opening 8, against which the tube end 5 rests.

[0038] In the plug connection arrangement 7, an unintentional migration of the tube end 5 out of the receiving opening 8 is prevented by a retaining device 16, which is implemented according to a preferred embodiment of the invention and apart from the Fig. 1 to 3 also individually from a perspective in Fig. 4 is shown. As is particularly evident in Fig. As can be seen in Figure 4, this holding device 16 comprises a C-shaped support section 17, the C-shape of which is defined by segments 18 to 24. The segments 18, 20, 22, and 24 together define a first inner diameter 25 of the support section 17 and each have an end face 26, 27, 28, and 29, respectively. The end faces 26 to 29 on segments 18, 20, 22, and 24 are designed to point in an axial direction 30, which is Fig. 4 is indicated by an arrow.

[0039] Compared to segments 18, 20, 22, and 24, segments 19, 21, and 23 of the support section 17 are offset further outwards and define a second inner diameter 31 of the support section 17, this second inner diameter 31 being larger than the first inner diameter 25. Segment 19 connects segments 18 and 20, while segments 20 and 22 are connected to each other via the intermediate segment 21, and segments 22 and 24 are connected to each other via the intermediate segment 23.

[0040] The support section 17 of the holding device 16 is designed to be spring-like, wherein the free ends 32 and 33 connecting to the segments 18 and 24 are bent outwards transversely to the axial direction 30, and the support section 17 can be elastically expanded at the ends 32 and 33.

[0041] As also in Fig. As can be seen in Figure 4, the holding device 16 has several holding sections 34, 35, and 36, each extending from the support section 17 in the axial direction 30. Holding section 34 projects from segment 19, holding section 35 projects from segment 21, and holding section 36 projects from segment 23. Each of the holding sections 34, 35, and 36 has a first subsection 37, 38, and 39, respectively, which extends essentially straight in the axial direction 30 from the corresponding segment 19, 21, and 23, respectively, and transitions on a side facing away from the corresponding segment 19, 21, and 23 into a second subsection 40, 41, and 42 of the respective holding section 34, 35, and 36, respectively. Each of these second subsections 40, 41, or 42 is curved inwards transversely to the axial direction 30 and connects the respective first subsection 37, 38, or 32.39 with a third subsection 43, 44, or 45, respectively. In the case of the respective holding section 34, 35, or 36, this third subsection 43, 44, or 45 extends essentially straight transversely to the axial direction 30 inwards and forms an end 46, 47, or 48 of the respective holding section 34, 35, or 36, respectively.

[0042] The retaining sections 34 to 36 of the retaining device 16 are also designed to be resilient, such that their ends 46 to 48 can be deflected elastically outwards transversely to the axial direction 30. Furthermore, the retaining sections 34 to 36 are integrally formed with the support section 17, so that the retaining device 16 is a single-piece component. Preferably, the retaining device 16 is made of metal, for example, spring steel.

[0043] To form the plug connection arrangement 7, the holding device 16 is laterally placed on an outer circumference of the connecting stub 3 in a mounting direction 49, wherein the mounting direction 49 is in Fig. 2 is indicated and perpendicular to one also in Fig. The insertion direction 50 shown in Figure 2 runs into which the pipe 2 is inserted with its pipe end 5 into the receiving opening 8. During placement, the holding device 16 engages the connecting piece 3 with its support section 17 at a groove 51, which is provided on the outer circumference of the connecting piece 3 and which forms a circumferential collar 52 of the connecting piece 3 at its connecting end 9. During placement, the support section 17 of the holding device 16 is elastically expanded, with this elastic expansion being facilitated by the curved ends 32 and 33 of the support section 17. As shown in particular in Fig. As can be seen in Figure 3, the support section 17 of the holding device 16 projects into the groove 51 with segments 18, 20, 22 and 24, whereby the support section 17 can subsequently be supported on a support shoulder 52 via the end faces 26 to 29, which is defined by the collar 52 pointing in the direction of insertion 50.

[0044] When the retaining device 16 is placed onto the connecting piece 3, its retaining sections 34 to 36 engage a shoulder 54 of the inserted pipe end 5. This shoulder 54 is designed to point away from the insertion direction 50 at the thickening 12. As can be seen in particular from Fig.As can be seen in Figure 3, corresponding pockets 55, 56, and 57 are defined at the shoulder 54 for the retaining sections 34 to 36 of the retaining device 16. These pockets are bounded circumferentially by webs 58 and 59, 59 and 60, and 60 and 61, respectively. The pockets 55 to 57 are oriented by the webs 58 to 61 from their openings such that the retaining sections 34 to 36 of the retaining device 16 can slide into their respective pockets 55, 56, and 57 with elastic deflection when placed onto the connecting piece 3. After this sliding, the retaining sections 34 to 36 then engage behind the shoulder 54 of the pipe end 5 with their respective ends 46 to 48.

[0045] On one side of the step 54 facing away from the pocket 56, a further rib 62 is provided between the webs 58 and 61, which ensures that the pipe 2 with the pipe end 5 cannot be fixed in the connecting piece 3 via the retaining device 16 rotated by 180°.

[0046] The retaining device 16 prevents the pipe end 5 from unintentionally migrating out of the connection stub 3 by, on the one hand, the contact of the end faces 26 to 29 with the support shoulder 53 and, on the other hand, by the engagement of the shoulder 54 with the retaining sections 34 to 36 in a form-fitting manner. The retaining device 16 with its retaining sections 34 to 36 is guided along the outside of the collar 52 of the connection stub 3, beyond its connection end 9, and then inwards, thus ensuring a particularly compact fixation of the pipe end 5 to the connection stub 3. Reference sign 1. Piping system 2 pipes 3 connection spigots 4 connection spigots 5 pipe ends 6 Pipe ends 7 Plug connection arrangement 8 Inlet opening 9 End of connection Part 10 Part 11 12 Thickening 13 Nut 14 Sealing ring 15 strikes 16 Holding device 17 Support section 18 segments 19 segments 20 segments 21 Segment 22 segments 23 Segment 24 segments 25 inner diameter 26 Front surface 27 Front surface 28 Front surface 29 Front surface 30 axial direction 31 inner diameter 32 End 33 End 34 Stop section 35 Stop section 36 Stop section 37 Subsection 38 Subsection 39 Subsection 40 Subsection 41 Subsection 42 Subsection 43 Subsection 44 Subsection 45 Subsection 46 End 47 End 48 End 49 Direction of placement 50 Insertion direction 51 Nut 52 Bund 53 Supporting shoulder Paragraph 54 55 bags 56 bags 57 bags 58 Bridge 59 Bridge 60 Bridge 61 Bridge 62 Bridge QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2005 / 045299 A1

[0003]

Claims

[1] Holding device (16) which is designed to prevent a pipe end (5) of a pipe (2) inserted into a receiving opening (8) of a connecting piece (3) in a plug-in connection arrangement (7) from moving out of the receiving opening (8) in a form-fitting manner, and which comprises a support section (17) which is C-shaped, wherein the support section (17) is provided in the plug-in connection arrangement (7) for being placed on an outer circumference of the connecting piece (3) and subsequently for gripping the outer circumference of the connecting piece (3), and wherein the support section (17) forms at least partially a support surface oriented in an axial direction (30), on which, in the plug-in connection arrangement (7), the holding device (16) is axially supported by the connecting piece (3) after gripping the outer circumference of the connecting piece (3), characterized by, that at least one retaining section (34, 35, 36) is provided, which extends from the support section (17) in the axial direction (30), and that the at least one retaining section (34, 35, 36) has one end (46, 47, 48) facing away from the support section (17) and extends inwards transversely to the axial direction (30), wherein each end (46, 47, 48) is provided in the plug connection arrangement (7) for engagement behind the pipe (2) after the outer circumference of the connecting piece (3) has been engaged and in the inserted state of the pipe end (5). [2] Holding device (16) according to claim 1, characterized by, that the support section (17) has several segments (18, 20, 22, 24) which together define a first inner diameter (25) of the C-shaped support section (17) and which, with end faces (26, 27, 28, 29), each form part of the support surface, wherein adjacent segments (18, 20; 20, 22; 22, 24) are connected to each other via an intermediate segment (19, 21, 23) on which the at least one retaining section (34, 35, 36) is projecting and which lies on a second inner diameter (31) of the support section (17) which is larger than the first inner diameter (25). [3] Holding device (16) according to claim 2, characterized by , that the free ends (32, 33) of the C-shape of the support section (17) are each designed to curve outwards transversely to the axial direction (30). [4] Holding device (16) according to one of claims 1 to 3, characterized by, that the support section (17) is designed to be resilient and is elastically expandable at the free ends (32, 33) of its C-shape. [5] Holding device (16) according to any of the preceding claims, characterized by , that the at least one retaining section (34, 35, 36) is connected to the support section (17) by a first subsection (37, 38, 39) which extends from the support section (17) in the axial direction (30) and transitions into a second subsection (40, 41, 42) in each case, wherein each second subsection (40, 41, 42) extends from each first subsection (37, 38, 39) in a curved direction inwards and transitions there into a third subsection (43, 44, 45) which extends inwards in each case transversely to the axial direction (30) and forms one end (46, 47, 48) in each case. [6] Holding device (16) according to any of the preceding claims, characterized by, that the at least one retaining section (34, 35, 36) is designed to be resilient and that each of its ends (46, 47, 48) can be deflected elastically outwards transversely to the axial direction (30). [7] Holding device (16) according to one of the preceding claims, characterized by , that several holding sections (34, 35, 36) are provided, each of which connects to the C-shaped support section (17) at circumferential intervals. [8] Plug connection arrangement (7) in which a tube (2) with a tube end (5) is inserted in an insertion direction (50) into a receiving opening (8) which opens at the connection end (9) of a connecting piece (3), wherein a retaining device (16) according to one of claims 1 to 7 is provided, which can be placed in a fastening position in which the retaining device (16) with its support section (17) is placed on an outer circumference of the connecting piece (3) and prevents the tube end (5) inserted into the receiving opening (8) from moving out of the receiving opening (8) by means of a positive locking mechanism, for this purpose the retaining device (16) in its fastening position is supported on the one hand by its support section (17) on a support shoulder (53) which is defined on the outer circumference of the connecting piece (3) pointing in the insertion direction (50), and on the other hand with its at least one retaining section (34, 35, 36) on the side of the Rohrs (2) refers to paragraph (54),which is designed to point towards the pipe (2) in the opposite direction to the insertion direction (50). [9] Plug connection arrangement (7) according to claim 8, characterized by , that the support shoulder (53) is defined by a circumferential collar (52), wherein the at least one retaining section (34, 35, 36) in the fastening position of the retaining device (16) is led outside the collar (52) to the connecting end (9) of the connecting stub (3). [10] Plug connection arrangement (7) according to claim 9, characterized by , that the circumferential collar (52) is formed by a groove (51) with which the connecting piece (3) is provided around its outer circumference and into which the retaining device (16) is inserted in its fastening position with its support section (17). [11] Plug connection arrangement (7) according to one of claims 8 to 10, characterized by, that paragraph (54) defines a corresponding support area for each end (46, 47, 48) of the at least one holding section (34, 35, 36) of the holding device (16). [12] Plug connection arrangement (7) according to claim 11 and with a holding device (16) according to claim 7, characterized by, that the placement of the holding device (16) with its support section (17) on the outer circumference of the connecting piece (3) takes place in a placement direction (49) oriented transversely to the insertion direction (50), wherein the associated support areas on the shoulder (54) are designed as pockets (55, 56, 57), which are each designed to be open in the opposite direction to the placement direction (49), so that when the holding device (16) with its support section (17) is placed on the outer circumference of the connecting piece (3) and when the pipe end (5) is inserted into the receiving opening (8), each individual holding section (34, 35, 36) of the holding device (16) is inserted into the respective pocket (55, 56, 57) from the pipe (2). [13] Plug connection arrangement (7) according to claim 12, characterized by , that each individual pocket (55, 56, 57) is limited on both sides in the circumferential direction of the paragraph (54). [14] Conduit system (1) for a hydraulic supply system, in particular for an electrically driven motor vehicle drive axle, comprising at least one pipe (2) which is attached at at least one pipe end (5) to each associated connection nozzle (3) in each plug connection arrangement (7) according to one or more of claims 8 to 13. [15] Conduit system (1) according to claim 14, characterized by , that the at least one pipe (2) is attached at one pipe end (5) to an associated connection fitting (3) via the plug connection arrangement (7), whereas the at least one pipe (2) is inserted with its other pipe end (6) into another associated connection fitting (4) without attachment.

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