WO2011069937A1

WO2011069937A1 - Crimp coupling for a hose connection and method for producing a hose connection comprising a crimp coupling

Info

Publication number: WO2011069937A1
Application number: PCT/EP2010/068918
Authority: WO
Inventors: Josef Steinbeck; Carmen Drave; Stefan HÜBL; Jonathan Messerschmidt
Original assignee: Contitech Kühner Gmbh & Cie.Kg
Priority date: 2009-12-08
Filing date: 2010-12-06
Publication date: 2011-06-16
Also published as: EP2510271A1; EP2510271B1

Abstract

The invention relates to a crimp coupling for a hose connection, said coupling comprising a pipeline nipple for connecting a hose to which the hose is secured by means of a coaxial crimp ferrule that is deformed under radial pressure. A sealing ring is arranged in a circumferential recess of the nipple. The nipple (12) is produced using an axial non-cutting forming process and comprises a folded outer stop (14), which is adjoined by a flat support zone (15). The sealing ring is arranged in an inwardly directed bulge (17) in the nipple wall (18). The crimp ferrule (24) comprises a radial, circular ring-shaped wall (25), which abuts the stop collar (14) and is secured there by means of crimping. The crimp ferrule (24) comprises two radial press regions (33 and 35).

Description

description

Crimping coupling for a hose connection and method for producing a hose connection with a crimping coupling

The invention relates to a crimping coupling for a hose connection with a pipe nipple for connecting a hose and a coaxial, deformed under radial pressure ferrule, wherein in a circumferential recess of the nipple, a sealing ring is arranged.

For the production of rigid-flexible piping systems, which consist on the one hand of flexible hoses made of elastomeric material with or without an inner sealing foil of thermoplastic material as inner layer and on the other hand of tubes of metallic materials, e.g. Aluminum, and in particular be used in mobile air conditioning systems for motor vehicles, it is known to postpone the hose closely fitting on a nipple formed into the end of the tube and fix there with the aid of a ferrule. The tube is clamped between the ferrule and the nipple. To minimize leakage of the guided fluids throughout the life of the conduit system, in the area of engagement, i. the pinch zone, one or more sealing rings of one

Elastomer material between the nipple and the pushed hose.

When mounting the crimp, the ferrule is attached to the nipple in a separate process step after mounting the sealing rings in a separate process step with a front end on the nipple with distance to the free end of the nipple firmly or loosely or pushed loose fitting on the hose end. Then the tube is pushed onto the nipple and fixed by pressing the radial compression of the ferrule on the nipple.

From DE 91 02 495 U1 a crimp is known, which has two spaced apart on the circumference of the nipple arranged O-rings, which in each case one Semicircular cross-section having groove in the circumference of the nipple are arranged as a sealing seat. The preparation of these two grooves as sealing seats for the O-rings requires a radial shaping of the grooves via a machining process, such as screwing, and a subsequent deburring.

From DE 41 20 529 C2 a crimp is known, which has an arranged on the circumference of the nipple O-ring in an incorporated into the surface of the nipple groove. At intervals to the O-ring annular retaining ribs on the nipple are present, which are intended to prevent a redrawing of the hose from the nipple after pressing through the ferrule. The production of the groove as a sealing seat for the O-ring and the production of the retaining ribs require several separate mechanical processing steps, such as radial forming or machining processes, such as screwing and subsequent deburring. Machining processes involve the risk of chips being introduced into the pipeline, which in the worst case can lead to failure of the fluid system.

From US 4 522 435 a crimp is known, the crimp sleeve rests with a radially extending end wall against a compression collar on the nipple. On the

The circumference of the nipple is an O-ring arranged in a machined groove. At axial distances to the O-ring sawtooth-like annular ribs are provided on the nipple, which are to act against a withdrawal of the hose from the nipple after being pressed through the ferrule. The production of the groove as a sealing seat for the O-ring and the production of the annular ribs require several separate mechanical

Processing steps, such as radial forming or cutting processes, such as screwing and subsequent deburring.

From US 2004/0130148 A1 a crimp is known, the ferrule with the circular opening end of a radially extending end wall in a

annular, rectangular circumferential groove is inserted on the nipple. On the circumference of the nipple two O-rings are arranged in each case a groove incorporated by radial indenting the nipple wall. The preparation of the grooves as sealing seats for the O-rings and the production of the rectangular peripheral groove for the end wall of the ferrule requires a separate mechanical non-cutting processing steps, a radial forming the wall of the nipple. About suitable Rollpresswerkzeuge the wall of the nipple is pressed locally. This used double O-ring seal has the disadvantage that the circumferential groove and the grooves that make up the sealing seats, constrictions of the inner Cross-section, whereby pressure losses occur in the fluid circuit and the performance of the fluid system is reduced. In addition, the integration requires a relatively large amount of space.

The invention has for its object to design a crimp of the type described above such that the production costs are minimized and a high tightness is achieved.

The object is achieved by the following features:

- The geometry of the nipple is made by an axial chipless forming process; - The nipple is in the pipe facing area with a folded, outer

Provided stop collar, followed by a flat contact zone connects;

- The support zone terminates at a compression collar with a smaller outer diameter, to which an inwardly directed bulge of the nipple wall connects, in which the sealing ring is arranged;

- Towards the free end of the nipple is a decreasing in diameter

Run-off zone arranged;

- In the ferrule a radial annular wall is arranged, which rests against the stop collar, on its other side of a flanged

End portion of the ferrule is included;

- The ferrule has between stop collar and Stauchbund close to

Stop collar on a first radial pressing area and in the region of the outlet zone on a second radial pressing area.

The crimped coupling according to the invention is characterized by a transmission of high holding forces of the hose connection in the axial and radial directions. There is a greater power transfer between pipe and integration in both the axial and in the radial direction possible. The axial force transmission takes place by the Umbordelung the Anschlagbundes with the end portion of the ferrule. The radial force transmission takes place by the flaring on the stop collar.

By the invention, a tight and tensile bonding of the hose is achieved in the crimp, so that even with only one sealing ring on the nipple the requirements are met, which is reflected in a shorter design of the crimp advantageously advantageous. In the invention, the minimum internal cross-section in the region of the integration can be increased by appropriately selected deformation of the pipe end to the nipple, whereby the flow conditions are optimized and the pressure losses are reduced.

In an advantageous embodiment of the invention, the bulge of the nipple wall for the sealing seat is formed in cross-section with an elongated footbed, in which a D-shaped sealing ring is arranged. This is wider in comparison to the classic O-ring, but has a lower height. As a result, the groove depth of the sealing seat can be smaller and the sealing surface is wider. The D-ring sits on the nipple better than the O-ring due to the wider contact surface.

In a further advantageous embodiment of the invention, the ferrule in the region of the sealing seat on a third radial pressing area. This third series of presses allows a clearly defined sealing force to be set over the sealing seat.

The invention also relates to a method for producing a hose connection with a crimp coupling.

In the invention, the nipple geometry of the hose binding is produced exclusively by an axial forming process, which takes place in two or three steps in one machine operation. There is no additional radial forming process (rollers) for introducing the sealing seat necessary. The complexity of the entire manufacturing process is at one

Minimum reduced. By avoiding machining process steps, potential problem areas, such as contamination by material particles, e.g. arising during cutting processes, already excluded by the process.

The assembly process is simplified by the automatic correct positioning of the ferrule on the stop collar. As a result, only one process step in the form of an axial forming process for pressing the integration is necessary.

The invention provides a crimp-type coupling with a robust, i. simple design created by a uniform compression process to form two compression collars on the pipe nipple.

Reference to the drawings, embodiments of the invention are explained in more detail below. It shows Figure 1 is a compressed hose connection with a nipple whose geometry is created by chipless, upsetting deformation, and with a hinged, deformed ferrule in longitudinal section.

Fig. 2 in a schematic detail view a half longitudinal section through a sealing seat having a nipple and loosely deferred, unpressed

Crimp sleeve omitting the hose end to be connected;

3 shows a schematic detail of a half longitudinal section through a compressed crimp with surrounding pressing tool.

Fig. 4 shows an embodiment of the nipple produced by upsetting with a smaller inner diameter in the contact zone of the hose than the

Inner diameter of the adjacent pipeline;

Fig. 5 shows an embodiment of the nipple produced by upsetting with the same inner diameter in the support zone of the hose as the

Inner diameter of the adjacent pipeline;

Fig. 6 shows an embodiment of the nipple made by upsetting with a larger inner diameter in the contact zone of the tube than the

Inner diameter of the adjacent pipeline;

7 is an external view of the crimping coupling with circumferentially extending straight pressing lines in the radial pressing areas;

Fig. 8 is an exterior view of the crimp with circumferentially extending

W-shaped or zig-zag shaped pressing line in a radial pressing area.

From Fig. 1, a hose connection with a crimp coupling is apparent, which has a pipe 1 1, the end of which is provided with a molded nipple 12, the inner passage 13 is aligned with the pipe 1 1. The nipple geometry for the hose binding is by an axial forming process, preferably a

Upsetting presses, produced. The nipple 12 is in the pipe 1 1 facing area with a produced by the compression process, folded, outer

Stop collar 14 provided, to which a flat support zone 15 connects.

This support zone 15 terminates in a compression collar 16 smaller outer diameter, to which a formed with a cross-sectional elongated footbed 17 bulge 17 of the nipple wall 18 connects, which is a sealing seat 19 for a made of elastomeric,

permeationsarmem material (eg EPDM, HNBR) existing sealing ring 21, which is seen in cross-section D-shaped. The D-shaped sealing ring 21 is wider compared to the classic O-ring, but has a lower height. This can the groove depth of the sealing seat is lower and the sealing surface is wider. The D-ring sits on the nipple better than the O-ring due to the wider contact surface.

At this bulge 17 connects to the free end of the nipple 12 towards a decreasing in diameter outlet zone (Aufschieberampe) 22, by the sliding of the end of a flexible tube 23 is facilitated.

The between the nipple 12 and a coaxially arranged, radially deformed

Squeezing sleeve 24 clamped hose end 23 is located on the front side of a radial annular wall 25 of the ferrule 24 at.

The radial annular wall 25 of the ferrule 24 serves as

Positioning stop for the ferrule on the stop collar 14. On the other hand, the stop collar 14 of a bent end portion 26 of

Crimp sleeve 24 includes. The ferrule 24 is thereby positioned and fixed. The ferrule 24 is pressed radially inward in the region of the support zone 15 and in the region of the outlet zone 22, resulting in a sufficient clamping of the

Hose end 23 on the nipple 12 leads.

In Fig. 2, the nipple 12 and the over-pushed ferrule 24 are shown in the unpressed state and without inserted hose end.

The nipple 12 produced from the deformed tube end 1 1 is produced by an axial forming process (cold forming) in several stages. The essential

Features of the geometry of the nipple 12 thus created are the following:

- Stop collar 14 as a positioning stop for the undeformed ferrule 24 and to generate the counterforce for hanging (crimping) of the end portion 26 of the ferrule 24th

- Stauchbund 16 defines for a precise positioning of the sealing ring 21 and prevents displacement of the sealing ring 21 during the sliding of the tube 23rd

- Sealing seat 19 in the bulge 17, which is semicircular here, the nipple wall 18th

- Auslaufzone (Aufschieberampe) 22 expands the tube 23 to prevent during assembly a displacement of the sealing ring 21, which is an O-ring here.

The radial wall 25 in the ferrule 24 is on the one hand a mounting stop, which ensures compliance with the defined position of the ferrule 24 and on the other hand, the counter surface of the suspension is through which the radial power transmission is generated. In Fig. 3, the pressing tool 31 for pressing the ferrule 24 is shown schematically over the corresponding pressing portions of the crimped compression coupling. The pressing has different functional areas, which are realized by different stages on the pressing tool 31. The tool stage 32 forms the sealing and settling zone 33. The tool stage 34 forms the pressing portion 35 with the holding function for the tube 23. The tool stage 36 is rectangular or triangular and provides the beading of the end portion 26, through which the axial fixation of the ferrule 24 is reached.

In the pressing tool 31 nipple 12 and ferrule 24 are centered to each other and then the tube 23 is pushed onto the nipple 12. In one operation, the tube 23 is fastened with the pressing tool 31 by the compression of the ferrule 24 and the ferrule 24 additionally fixed to the nipple 12 of the pipe 1 1. The axial fixation of the ferrule is effected with the tool stage 36, by which the end portion 26 is crimped around the stop collar 14. This axial fixation significantly increases the pull-off forces of the compression coupling.

The radial fixation of the tube 23 is in the pressing areas 33 and 35

produced. It guarantees that no twist takes place between the nipple 12 and the hose 23. By pressing 35 of the ferrule 24 directly behind the compression collar 16, the holding force between the tube 23 and nipple 12 is additionally increased. The compression 33 has two functions. On the one hand, the area 33 of reassurance serves; the movements of the hose 23 are damped, and on the other hand, the area 33 of the first seal of the nipple 12 serves.

The nipple 12 can be designed differently. In the following, three variants will be described with reference to FIGS. 4 to 6.

Fig. 4: D1> D2: The diameter D2 in the nipple area 12 is smaller than that

Pipe outside diameter D1 of the pipe 1 1.

d1 »d2: The pipe inside diameter d1 is larger than the minimum

Inner diameter d2 in the nipple area 12.

As a result, pressure losses may occur in this variant. Of the

inventive advantage due to the structurally simple and safe design compensates for this disadvantage but in some simple applications.

Fig. 5: D1 = D2 The pipe outside diameter D1 and the diameter D2 of the nipple area are the same size. d1> d2 Thus, the minimum inner diameter d2 of the

Nipple area smaller than the pipe inside diameter d1. By means of this variant, the pressure losses associated with the known solutions of the prior art due to their strong cross-sectional reductions in the nipple are minimized. By increasing the minimum internal cross-section and a more advantageous flow pattern of the guided medium, the pressure losses can be reduced to the minimum value of a clean pipeline.

Fig. 6: D1 <D2 The pipe outside diameter D1 is smaller than that

Diameter D2 of the nipple area.

d1 = d2 inner diameter d1 and minimum

Inner diameter d2 of the nipple 12 are the same.

In this variant, no cross-sectional constrictions arise. It comes closest to the pressure losses of a clean pipeline. The press picture of the deformed ferrule 24 may be different. In FIGS. 7 and 8, two variants are shown, which differ in the realization of the pressing region 35 with the holding function.

In Fig. 7, the pressing portion 35 is realized with the holding function by a radially encircling line-shaped press row which lies between wall 25 and compression collar 16.

As a result, the holding force between the hose 23 and nipple 12 is realized.

In Fig. 8, the pressing portion 35 is obtained by press-fitting which is W-shaped around the circumference. As a result, the length of the press line is increased and the pressure is flat. The holding force between hose 23 and nipple 12 can be further increased.

LIST OF REFERENCE NUMBERS

11 nipples

12 pipeline

13 internal passage

14 stop collar

15 contact zone

16 compression collar

17 bulge

18 nipple wall

19 sealing seat

21 sealing ring

22 outlet zone (slide-on lamp)

23 hose

24 ferrule

25 radial wall

26 End section of ferrule

31 pressing tool

32 tool level

33 Sealing and calming zone

34 tool level

35 Pressing area holding function

36 tool level

Claims

claims

1 . Crimp coupling for a hose connection with a pipe nipple for connecting a hose and with a coaxial, under radial pressure on the

Hose deformed ferrule, wherein in a circumferential recess of the nipple, a sealing ring is arranged,

characterized by the following features:

- The geometry of the nipple (12) is made by an axial chipless forming process;

- The nipple (12) is in the pipeline (1 1) facing region with a folded, outer stop collar (14), to which a flat support zone (15) is connected;

- The support zone (15) ends at a compression collar (16) with a smaller

Outer diameter, which is followed by an inwardly directed bulge (17) of the nipple wall (18), in which the sealing ring (21) is arranged;

- To the free end of the nipple (12) towards a decreasing in diameter outlet zone (22) is arranged - in the ferrule (24) has a radial annular wall (25) is arranged; which abuts the stop collar (14) which is surrounded on its other side by a flanged end portion (26) of the ferrule (24);

- The ferrule (24) has between the stop collar (14) and compression collar (16) close to the stop collar (14) has a first radial pressing region (35) and in the region of

Outlet zone (22) has a second radial pressing region (33).

2. crimping coupling according to claim 1, characterized in that the bulge (17) of the nipple wall (18) for the sealing seat (19) is formed in cross-section with an elongated footbed in which a D-shaped sealing ring (21) is arranged.

3. crimping coupling according to claim 1 or 2, characterized in that the

Squeezing sleeve (24) in the region of the sealing seat (19) has a third radial pressing region (33).

4. A method for producing a crimping coupling for a hose connection with a pipe nipple for connecting a hose and with a coaxial, deformed under radial pressure on the tube ferrule, wherein in a

Circumferential recess of the nipple is arranged a sealing ring, according to the features of claim 1,

characterized by the following steps:

- The geometry of the nipple (12) is produced by an axial chipless forming process by which a stop collar (14) as a positioning stop for suspending the ferrule (24), a compression collar (16) for accurate positioning of the sealing ring of the hose (23) in compressed state, a bulge (17) of the nipple wall (18) are formed as a sealing seat and a discharge zone (22);

- In a radial pressing operation by the radial compression of the ferrule (24) of the hose (23) mounted on the nipple (12) and the ferrule (24) at the same time on the nipple (12) of the pipe (1 1) by crimping the end portion (26) fixed to the stop collar (14).