GB2342133A

GB2342133A - A pipe coupling

Info

Publication number: GB2342133A
Application number: GB9821297A
Authority: GB
Inventors: David Charles Harvey; Uwe Heyden; Hans Arthur Maria Joos
Original assignee: TI Group Automotive Systems Ltd
Current assignee: TI Group Automotive Systems Ltd
Priority date: 1998-10-01
Filing date: 1998-10-01
Publication date: 2000-04-05
Anticipated expiration: 2018-10-01
Also published as: ES2190717A1; SE0001783D0; GB2346942A; GB9821297D0; SE0001783L; SE522702C2; DE19982053T1; GB0005589D0; WO2000020790A1; GB2342133B

Abstract

A pipe coupling for use in a hydraulic system comprises a pipe 701 and a connector 702, the pipe is inserted a distance d into the connector 702 and a punch (304, figure 4B) forces a pipe portion 703 to expand into a cavity 704 of the connector thereby effecting a seal. The pipe may extend through the entire length of the connector (801, figure 8) or, alternatively, may be provided with dual flanges (905, 907, figure 9) and the connector (903, figure 9) radially crimped to effect a seal. Also a latch (1008, figure 10A or 1101, figure 11) may be utilised to seal the components, axial forces (1009, figure 10A or 1111 figure 11) forcing the latch (1008, figure 10A) or thinned portion (1110, figure 11) into a cavity (1006, figure 10A or 1102, figure 11). The male connector may be connected to a female connector (1202, figure 12) by a circlip (1203, figure 12).

Description

BUA-P101-GB 2342133 Pipe Connector The present invention relates to

connectors configured to be attached to fluid-conveying pipes.

Fluid-conveying pipes or tubes are used in many applications where it is desirable to transfer a fluid within a system or where the transfer of fluid is being used to convey force (as in brake or clutch applications) or thermal energy, as in refrigeration, air conditioning or heating applications etc. Within car engines for example, metal hydraulic pipes are used for the transfer of force, particularly in clutch systems and brake systems. Historically, pipes or tubes of this type were connected manually using screw threaded arrangements but more recently there has been a trend towards using snap fit connectors that are more easily assembled, particularly in environments such as modem engine cavities where working space is at a premium.

Connectors are known in which a male connector, having a defined outer profile, connects with a co-operating female connector and connectors of this type are widely used to the extent that the automotive industry would expect any new connector to be compatible with existing profiles.

Furthermore, these known connectors provide a very satisfactory hydraulic seal at the connector/connector interface. However, a problem with known connectors of this type is that their interaction in terms of the connector/pipe interface is less than ideal. Known connectors require a narrow flange to be formed at the end of a co-operating pipe, typically having a length of one point five millimetres on a six millimetre diameter pipe. This allows the end of the pipe to be crimped to the connector by applying compressive force to the connector end.

According to a first aspect of the present invention, there is provided a connector configured to be attached to a fluid conveying pipe, wherein said pipe is receivable within said connector such that the end of said pipe is displaced a significant distance into the connector, including means displaced BUA-PM-GB from the end of the pipe for securing the pipe to the connector.

In a preferred embodiment, the means for securing the pipe to the connector is displaced from the end of the connector. Preferably, the connector includes an internal cavity configured to facilitate radial expansion of the pipe so as to secure the pipe to the connector. The radial pipe expansion may be effected by the application of axial force to the pipe.

In a preferred embodiment, the connector includes an O-ring located between the end of the connector and the portion of the pipe secured to the connector.

In an alternative preferred embodiment, the securing means comprises a first flange at the end of the pipe, a second flange displaced from the end of the pipe and an O-ring positioned between said flanges.

In a third alternative preferred embodiment, the securing means includes a latch insertable between the pipe and the connector. The latch may be configured to snap-fit into a cavity within the connector or the latch may be configured to expand into a cavity within said connector. In a preferred embodiment, the latch includes a thinned portion arranged to expand upon the application of force upon said latch.

According to a second aspect of the present invention, there is provided a method of attaching a connector to a fluid conveying pipe, comprising the steps of inserting a pipe into a connector such that the end of the pipe is displaced a significant distance into the connector; and applying force to the assembly so as secure the pipe to the connector at a position displaced from the end of the pipe.

Preferably, force is applied axially to the pipe so as to cause the pipe to expand into an expansion cavity within the connector.

The invention will now be described by way of example only, with reference to the accompanying drawings, in which:

Figure I shows a typical engine compartment of a motor vehicle having a hydraulic clutch system with male and female connectors; BUA-PM-GI3 3 Figure 2 shows a cross-section of the male and female connectors identified in Figure 1; Figures 3, 4A, 4B, and 5 detail procedures for applying a pipe to the male connector shown in Figure 2; Figure 6 shows a completed assembly, with a male connector attached to a pipe, fabricated in accordance with a procedure shown in Figures 3 to 5; Figure 7A details an engineering cross-section of the male terminated pipe shown in Figure 2 and Figure 78 details a similar male terminated pipe as shown in Figure 7A, modified slightly by having an extended connector; Figure 8 details a first alternative embodiment; Figure 9 details a second alternative embodiment; Figure 10A details a third alternative embodiment having a sphrig retaining latch and Figure 10B details the spring retaining latch identified in Figure 1 OA; Figure 11 details a fourth alternative embodiment; and Figure 12 shows a fully assembled male and female connector of the type identified in Figure 1.

The embodiments have been developed to provide improved assemblies for application as hydraulic parts in automotive clutch systems.

However, it must be emphasised that the embodiments and the embodied inventions may have application elsewhere in environments where fluid conveying pipes are required to be terminated.

A portion of an engine compartment of a motor vehicle is shown in Figure 1, having a clutch system 101. Hydraulic fluid is transported within the clutch system via metal pipes 102, 103 and connections between pipes are made by attaching a male connector 104 to a first pipe with a cooperating female connector 105 being attached to a co-operating pipe.

Male connector 104 and female connector 105 are detailed in crosssectionin Figure 2. The male connector 104 includes an 0-ring 201 to BUA-P101-GB 4 provide a hydraulic seal between its outer profile 202 and the corresponding inner profile 203 of the female connector 105. This interface is well known and tested within the automotive industry and embodiments disclosed herein, in terms of male connectors and female connectors, connect with known female and male connectors respectively, in addition to connecting with each other. Furthermore, connectors of this type may also be attached directly to engine components, or manufactured as an integral part of a component, allowing a suitably connected tube or pipe to be interfaced therewith.

The embodiment shown in Figure 2 represents a first preferred embodiment for attaching pipes (102, 103) to both the male and female connectors (104, 105). Unlike known connectors, configured to receive fluid conveying pipes, the pipe is receivable within the connector such that the end of the pipe is displaced a significant distance d into the connector. Thus, as shown in Figure 2, the pipes are not merely held at their ends 204 but actually enter within the connector for a significant portion of the connectors length; that is for a significant distance d as required by the present invention.

The pipes are held in place by arrangements for securing a pipe to a connector, wherein these securing arrangements are displaced from the end of the connector, thereby providing a more secure mechanical and hydraulic interface between the pipes 102, 103 and the connectors 104, 105.

In the embodiment shown in Figure 2, each connector includes an internal cavity. Male connector 104 is configured with an internal cavity 205, with its co-operating female connector 105 having a similar internal cavity 206. Hydraulic sealing between the male connector 104 and its cooperating pipe 102 is established by the provision of an O-ring 207, with a similar 0 ring 208 being provided within the female connector 105, to provide a hydraulic seal between a connector and its respective pipe.

During an assembly process, the internal cavities 205 and 206 facilitate radial expansion of a pipe so as to secure the pipe to its connector.

Thus, an assembly process is required so as to effect the radial expansion of BUA-P101-GB the pipe by mechanisms configured to apply an axial force. Procedures for applying pipe 102 to male connector 104 are illustrated in Figures 3, 4A, 4B and 5.

In Figures 3, 4A and 5, male connector 103 is shown in exploded cross-section for illustrative purposes only and it should be appreciated that the male connector remains intact during the attachment process. Pipe 102 is secured by a clamp 301 so as to hold the pipe durling the attachment operation. Male connector 104 has O-ring 207 inserted within an O-dng cavity 302. Thereafter, pipe 102 is inserted within the axial bore 303 of the connector through O-ring 207, as illustrated in Figure 3.

Axial force is applied to end 204 of pipe 102 by a punch 304 configured to traverse axially towards pipe 102, in the direction of arrow 305, for a predetermined distance, thereby applying an appropriate force to effect the required expansion of the pipe. Punch 303 is supported, in a spHng loaded manner, within a punch holder 306. Punch holder 306 abuts against the connector 103 as the punch extends therethrough in a spdng loaded fashion.

On application of the required force by punch 304, pipe 102 expands into cavity 205 as illustrated in Figure 4A. In this way, the pipe 102 is mechanically secured within the connector 104, with hydraulic integdty being provided by O-ring 207. In addition to pipe 102 expanding into cavity 205, an overall radial expansion of pipe 102 occurs thereby increasing the overall interference of the outside surface of pipe 102 against the inside of bore 303.

The instant shown in exploded view in Figure 4A is also shown in cross section in Figure 4B. Force is applied by punch 304 which contacts against an end wall 401 of pipe 102. This causes an overall radial expansion of pipe 102 within bore 303 and, in particular, causes an expansion into cavity 205.

Thus, Figures 4A and 4B show the maximum extent of travel for punch 304 after the punch has made contact with pipe 102 and has continued to extend, thereby applying force to pipe 102 and causing the BUA-PI01-GB 6 radial expansion into cavity 205.

At a distance displaced from the end of the pipe and at a distance displaced from the end of the connector, the pipe 102 expands into cavity 205 under the influence of force supplied by punch 304. Additional further expansion also occurs to provide a tight interference fit within bore 303.

As shown in Figure 4B, connector 104 is held firmly against punch 301 by means of compression spring 407, with the punch having travelled in the direction of arrow 305 so as to effect the radial expansion of pipe 102 into bore 303 and into cavity 205.

Thereafter, as shown in Figure 5, punch 304 retracts in the direction indicated by arrow 501, thereby leaving pipe 102 with a radially expanded portion 502 held tight by expansion cavity 205. The resulting assembly, showing male connector 104 attached to pipe 102 is shown in Figure 6.

An engineering cross-section of a terminated pipe 701, with a male connector 702, is shown in Figure 7A. This shows that the pipe has undergone radial expansion at 703 so as to occupy the space of an internal cavity 704, thereby providing a secure mechanical attachment between the pipe 701 and the connector 702. Furthermore, hydraulic performance is enhanced by the provision of O-ring 705. This configuration avoids problems associated with creating a flange at the end of the pipe. Pipe 701 has been received within the connector 702 such that the end of the pipe is displaced by a significant distance d into the connector 702. Furthermore, cavity 704, displaced from end 706 of the connector, provides for securing the pipe 701 to the connector 702 by the creation of radially expanded portion 703.

The embodiment shown in Figure 7A may be modified slightly as shown in Figure 7B. In Figure 7B the connector body is extended at 710 so as to provide a greater degree of material between a rear end 711 of the connector and O-ring 705. However, such a modification does result in the connector body being made longer than its usually accepted size.

BUA-P101-GB 7 An alternative embodiment of the present invention is detailed in Figure 8. A similar procedure to that illustrated with respect to Figures 3, 4A, 4B and 5 is performed so as to provide expansion of a pipe 801 at expansion region 802 into an internal cavity 803. In this embodiment, a fluid conveying pipe 801 traverses the full length of the connector 804 such that, at the end of pipe 801 a flange 805 is created which then abuts against an O-ring 806.

Pipe 801 is secured in similar fashion to the securing clamp shown in Figure 4, whereafter a punch, similar to punch 304, is applied to the end of the pipe so as to force out flange 805. An advantage of the arrangement shown in Figure 8 is that the entire length 807 of the internal bore of the connector receives the fluid conveying pipe, which may be advantageous in some environments. However, it should be appreciated that the pipe would not extend through the entire distance of the female connector, although it would be displaced through the female connector by a significant distance, as required by the present invention.

A second alternative embodiment is detailed in Figure 9. In this example, a fluid-conveying pipe 901 has a trumpet-shaped flare 902 applied to its end, similar to the provision of a flange in known configurations.

However, in accordance with the present invention, the pipe 901 enters into a connector, such as male connector 903, by a significant distance.

Furthermore, the pipe is secured at a posibon displaced from its end.

A second flange 905 is formed in the pipe at a position displaced from flanged end 902 of the pipe and an O-ring 906 is located between end flange 902 and displaced flange 905.

End flange 902 abuts against an internal diameter 907 of the connector. Towards the end of the connector, the internal diameter 907 is enlarged to provide a circular opening 908 configured to receive pipe 901.

Thereafter, the ends 909 of the connector are crimped so as to mechanically secure pipe 901 within the connector 903.

BUA-P101-GB 8 A third alternative embodiment is illustrated in Figure IOA. A fluid conveying pipe 1001 is processed in a way substantially similar to the processing of pipe 901 shown in Figure 9. Thus, the pipe is provided with a flared end flange 1002, a displaced flange 1003 and an O-ring 1004 located between said flanges.

Male connector 1005 has a significantly larger opening 1006 at its receiving end, thereby providing a significant cavity 1007 behind flange 1003 after pipe 1001 has been located within the connector. During the fabrication process, a circular retaining latch 1008 is placed around pipe 1001 and after the pipe has been located within cavity 1006, force is applied axially, in a direction of arrow 1009, to the latch 1008 thereby forcing said latch into the space of cavity 1006 and mechanically securing pipe 1001 within the connector 1005.

Latch 1008 is shown in cross-section in Figure 10B. The latch includes a plurality of fingers 1011 extending radially outwards beyond the end of the connector. Spaces of substantially similar revolution are included between each of these fingers, thereby allowing the fingers to deform radially, as indicated by arrow 1012, under the application of radially applied force.

Thus, in response to radial force being applied to fingers 1011, it is possible for the latch to be displaced axially in the direction of arrow 1013, thereby locating the latch within cavity 1006 of the connector. Thereafter, the radial force applied to fingers 1012 is removed, resulting in said fingers expanding elastically radially outwards, thereby firmly locating the latch within the cavity and thus securing the pipe 1001 within connector 1005.

An advantage of the third alternative embodiment, shown in Figures IOA and IOB, is that it facilitates the manufacture of connectors using alternative materials, such as plastics, whereupon the latch 1008 may effectively snap fit within its expansion cavity 1006. The use of an expanding latch is also exploited in a fourth alternative embodiment.

BUA-P101-GB 9 In a fourth alternative embodiment, as shown in Figure 11, a circular latch 1101 is forced into an expansion cavity 1102, similar to cavity 704 shown in Figure 7A. A male connector 1103 is shown in Figure I I having an internal bore 1104 of substantially similar diameter to a fluid-conveying pipe 1105. At the end 1106 of the connector 1103, connectable to the fluid conveying pipe 1105, the internal bore 1107 of the connector is enlarged and said enlarged region includes the expansion cavity 1102.

Pipe 1105 has a folded flange 1108 configured to abut against the end 1109 of the enlarged bore 1107, at a point at which it reduces to the standard bore size. Latch 1101 is applied to pipe 1105 before flange 1108 is formed therein and after forming said flange, the pipe 1105 is inserted within the connector 1103. In this way, the inwardly facing flange 1108 abuts and provides good sealing characteristics at its interface with the connector.

Latch 1101 includes a thinned portion 1110, configured to align with expansion cavity 1102. With the pipe positioned within the connector, force is applied against the latch in the direction of arrow 1111, thereby forcing expansion of thinned portions 1110 within expansion cavity 1102, so as to secure pipe 1105 within connector 1103. Thus, the expansion of thinned portions 1110 represents a plastic deformation of the latch so as to occupy the space of cavity 1102.

Having attached a male connector to a pipe and having attached a female connector to a pipe, the connectors are assembled as shown in Figure 12. A male connector 1201 engages within a female connector 1202 and the connectors are then firmly held in place by means of a circlip 1203, arranged to enter receiving slots 1204 within the female connector 1202 so as to engage tightly against a slot machined within the male connector.

The improved arrangement for attaching pipes to connectors facilitates their rapid fabrication with fewer failures being produced. Furthermore, by facilitating a more secure attachment between pipes and their connectors, greater flexibility is achieved during the application of the systems within BUA-P101-GB manufacturing processes, reducing production costs and increasing overall productivity.

BUA-P101-GB

Claims

1. A connector configured to be attached to a fluid-conveying pipe, wherein said pipe is receivable within said connector such that the end of said pipe is displaced a significant distance into the connector, including means displaced from the end of the pipe for securing the pipe to the connector.

2. A connector according to claim 1, wherein said means for securing the pipe to the connector is displaced from the end of the connector.

3. A connector according to claim I or claim 2, wherein said connector includes an internal cavity configured to facilitate radial expansion of the pipe so as to secure said pipe to the connector.

4. A connector according to claim 3, wherein said radial pipe expansion is effected by the application of axial force to the pipe.

5. A connector according to any of claims I to 4, including an 0 ring located between the end of the connector and the portion of pipe secured to the connector.

6. A connector according to any of claims 1 to 5, configured to receive a pipe fabricated in mild steel.

7. A connector according to any of claims I to 6, wherein the pipe does not extend the full distance of the connector.

8. A connector according to any of claims 1 to 6, wherein the pipe extends the full distance of the connector.

BUA-P101-GB 12

9. A connector according to claim 1, wherein said securing means comprises a first flange at the end of the pipe, a second flange displaced from the end of the pipe and an O-ring positioned between said flanges.

10. A connector according to claim 1, wherein said securing means includes a latch insertable between said pipe and said connector.

11. A connector according to claim 10, wherein said latch is configured to snap-fit into a cavity within said connector.

12. A connector according to claim 10, wherein said latch is configured to expand into a cavity within said connector.

13. A connector according to claim 10, wherein said latch includes a thinned portion arranged to expand upon the application of the force to said latch.

14. A connector according to any of claims 1 to 13, having an outer profile (male) configured to co-operate with a similar (female) connector having a matching inner profile.

15. A method of attaching a connector to a fluid conveying pipe, comprising the steps of inserting a pipe into a connector such that the end of the pipe is displaced a significant distance into the connector; and applying force to the assembly so as to secure the pipe to the connector at a position displaced from the end of the pipe.

BUA-PIOI-GB 13

16. A method according to claim 15, wherein said force is applied axially to the pipe so as to cause said pipe to expand into an expansion cavity within the connector.

17. A method according to claim 15 or claim 16, wherein the connector includes an O-ring and said pipe is inserted through said O- ring before said force is applied.

18. A method according to claim 15, wherein said force is applied to a latch restrained axially along said pipe.

19. A method according to claim 18, wherein said latch snap-fits into a cavity within said connector.

20. A method according to claim 18, wherein said latch expands within to an expansion cavity.

21. A connector configured to be attached to a fluid conveying pipe, substantially as herein described with reference to Figures 2, 3, 4A, 4B or 5; or with reference to Figure 7A; or with reference to Figures 7A and 7B; or with reference to Figure 8; or with reference to Figure 9; or with reference to Figures IOA and IOB; or with reference to Figure 11.

22. A method of attaching a connector to a fluid conveying pipe as herein described, with reference to Figures 2, 3, 4A, 4B or 5; or with reference to Figure 7A; or with reference to Figures 7A and 7B; or with reference to Figure 8; or with reference to Figure 9; or with reference to Figures IOA and IOB; or with reference to Figure 11.