JP2004502115A - Spin welded fluid connectors using metal tubes coated with plastic - Google Patents

Abstract

【Task】
A joint between the fluid connector body (42) and a metal tube (46) having an outer layer of plastic is formed by spin welding, and the portion of the connector body adapted to receive the tube is: An end face is provided for engaging the plastic outer surface of the mating conduit so as to form a continuous seal around the periphery between the fluid passageway in the connector body and the external environment. A flange (76) extending radially inward of the connector body extends into the internal passage at a location spaced from the end opening for receiving the metal tube in the connector body. This flange functions as an insertion restricting portion for the metal tube.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to fluid connectors and, in particular, to the sealing tubing end forms of such connectors, and further to effecting such interconnections. Related to the use of spin welding.
[0002]
[Prior art]
Rapid connection couplings have long been widely used in the US automotive industry. Such quick connectors may be applied in various forms, but are typically used in fuel systems and vapor recovery systems. The simplest and most cost-effective design is the plastic housing female type quick connector removably mated to the end of a metal male tube. The opposite end of the female housing most typically defines a stem having a member of an axially spaced barb formed on an outer peripheral surface thereof. On this, the tube end of a nylon or plastic tube is pressed. Such an arrangement is described in U.S. Patent No. 5,542,712, published August 6, 1996, entitled "Quick Connector Housing With Elongated Barb Design."
[0003]
[Problems to be solved by the invention]
In a fluid treatment system, it is inevitable that the connectors used will have properly interconnected female and male parts. A faulty connector will cause the connected system to leak fluid. This is particularly disadvantageous when the system is under pressure, and a leaking connector leaks pressurized fluid. In addition, recent federal legislation has mandated that the emission of hydrocarbons from automotive fuel and vapor recovery systems be significantly reduced. While conventional quick connectors are effective at mechanically maintaining the tube ends of the tubes in association with their associated connector bodies, they have not been able to adequately meet federal requirements. Absent. Also, the materials typically used, such as nylon 12, do not sufficiently prevent the penetration of hydrocarbons therethrough.
[0004]
This infiltration problem has been partially solved by the development of a co-extruded multilayer plastic tube having two or more different discrete layers, or a formation of plastic. One of these is specifically designed to provide an effective permeation layer and may avoid hydrocarbon emissions from the system. Generally, the most effective multilayer tubes use a relatively thick outer layer of a material that can withstand the external environment. The innermost layer is thin and is made of a material selected by its ability to prevent materials such as hydrocarbons, alcohols, and other materials in a mixture of fuels from defusing into the outer layer. It may also have a sufficient degree of electrical conductivity to dissipate the electrostatic charge generated by the flow of the fluid. Heretofore, it has been very difficult to obtain sufficient lamination properties between different polymer layers. Thus, it has been proposed to use one or more intermediate layers to adhere the inner and outer layers.
[0005]
The use of multi-layer tubing in fuel-related applications is dependent on the fuel and vapor of the system or a similarly harsh external environment, so that the end of the tubing, i. There is a problem because the (lamina) end of the laminate is necessarily exposed. Such exposure tends to reduce the adhesion between the various layers, resulting in delamination, i.e., separation of the layers, resulting in impaired system integrity, fuel contamination and further fluid flow. Cause blockage.
[0006]
A related problem is the dual aspect of commercially available quick connector devices: mass production and low selling prices, which often require the use of inexpensive, somewhat soft materials, and very little. It is caused by the complex contour of the extremely small inter-fitting components. These aspects generally increase the potential for misassembly. Mass production techniques, including automatic assembly, tend to exacerbate the problem of difficulty in finding component misassemblies or unacceptable dimensional tolerances. The accumulation of excessive dimensional tolerances can result in poor separation characteristics between the barbed stem and the plastic tubing, which can cause leakage. Misassemblies, such as those without an O-ring, can also cause leakage. In the case of multilayer tubing, dimensional and / or attachment issues can lead to mechanical delamination when inserting the tubing into a barbed stem. And a single-walled plastic tube or a multilayer structure with low hoop strength will loosen over time or at high temperatures, causing fluid leakage or weeping.
[0007]
[Means for Solving the Problems]
The present invention provides not only an assembly that overcomes the deficiencies of the prior art, but also a simple and inexpensive mechanically robust and environmentally resistant connection between the tube end of the tube and the connector body.
[0008]
The fluid connector of the present invention is designed for spin welding connections with metal tubes coated with plastic. The connector has a body with a through passage communicating a first opening adapted to receive a set of conduits with a second opening adapted to receive a tube. The end of the passage defines a surface at the second opening that sealingly engages the outer surface of the tube. This arrangement has the advantage of securely sealing the tube end with the connector body, preventing both fluid leakage and the ingress of contaminants from the environment.
[0009]
In one aspect, the invention is a fluid connector for a spin weld connection to a metal tube to which an outer layer of plastic is attached. The connector has a body defining a through passage communicating between a first opening adapted to receive a set of conduits and a second opening adapted to receive a tube.
[0010]
In another aspect, a fluid coupling has a connector body defining a through passage communicating between a first opening adapted to receive a conduit and a second opening opposite the first opening. An inner surface defining an inner weld surface is formed near the second opening of the body. The end of the metal tube has an outer plastic layer attached to it. This outer plastic layer is spin welded to the inner weld surface of the connector body.
[0011]
Preferably, the second opening defines an annular inner surface at one end of the through passage. A flange is positioned in the through passage spaced from the second opening and extends radially inward from the connector body into the through passage. The flange may be engaged with a tube tip.
[0012]
The spin-welded fluid connector of the present invention provides a secure and fully sealed connection between the end of the metal tube and the plastic connector body with a plastic outer layer attached to the metal tube. The present invention is provided by using a spin welding process in which the inner surface of a plastic connector body is spin-welded.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to FIGS. 1-4, a preferred embodiment of the present invention is described by taking an example of an application having a quick connector assembly, i.e., a fluid coupling 40, in which a connector 42 includes a metal tube. The end of member 44 and the plastic and metal tube end 46 are interconnected and preferably function to provide a fluid circuit for automotive applications.
[0014]
As best shown in FIG. 2, connector 42 has a generally tubular shape having a stepped bore 50 extending from first opening 52 to second opening 54. , A rigid shell plastic connector body 48 formed from glass filled nylon or other suitable material.
[0015]
The end of the metal tube member 44 extends into the lumen 50 through the first opening 52 as shown in FIG. An upset bead 56 axially spaced from the distal end 58 of the tube 44 removably engages a retainer 60 assembled with the body 48. An outer peripheral surface of the metal tube 44 is engaged with the main body 48 in the lumen 50 by a first elastic O-ring 62 and a second elastic O-ring 64 separated from each other by a spacer 66. , And is held in the position shown by a second spacer 68 and a top hat 70. As shown, a distal end 58 of the metal tube 44 can be inserted into the lumen 50 and mechanically engaged with the connector 42 without the use of tools or special assembly equipment. The end of the metal tube 44 can be removed from the connector 42 by elastically deforming the retainer 60.
[0016]
The intermediate step 72 in the lumen 50 of the connector body 48 is dimensioned to ensure a slip fit with the tip 58 of the metal tube 44 and establish intimate contact therewith. .
[0017]
A flange 77 is formed integrally with the main part of the connector main body 48, and extends axially to the left in FIG. The flange 77 terminates at a leading protrusion 80. This flange 77 is circular, concentric with the second opening 54 and defines an inner lumen 79.
[0018]
The plastic and metal tube end 46 preferably comprises a metal tube or conduit having a metal side wall 81 covered by an outer layer 82 of plastic material. This plastic outer layer 82 is firmly attached to the metal layer 81 by coextrusion and other known techniques.
[0019]
A special plastic and metal tube end 46 that is ideally suited for use in the present invention is a nylon 12 carbon steel (nylon) manufactured and sold by the assignee of the present invention under the trademark NYCLAD. It is a tube end made of 12-carbon steel. It will also be appreciated that other metal materials as well as other plastic materials can be used to practice the invention.
[0020]
Although the plastic outer layer 82 of the tube end 46 is described as a mono-wall layer, several different plastic layers are attached and connected to each other and to the metal tube end 81. It will be understood that a multi-layer structure consisting of at least two layers of plastic, with at least two layers of conductive material in between, can also be used for the tube end 46. Also, the innermost corner of the distal end 80 of the connector body 48 is lead-in to improve insertion of the tube end 46 into a lumen 79 near the extreme end of the connector body 48. It may be beveled or angled to give a profile.
[0021]
With reference to FIGS. 3 and 4, the spin welding process of attaching the plastic and metal tube ends 46 to the connector body 48 is described. As shown in FIG. 3, the tube end 46 is pre-positioned to be concentric with the second opening 54 and positioned slightly axially therefrom. The nominal outer diameter of the tube end 46 is slightly larger than the inner diameter of the leading projection 80, so that when the tube end 46 contacts the connector body 48, the two are pre-positioned and self-centered. To do so, the tip 96 first contacts the leading projection 80. This self-centering property also eliminates the need for guide mandrels during spin welding.
[0022]
An inner flange 76 is formed in the connector body 48 between the lumens 72 and 79. The flange 76 has a ring shape having a central aperture 78. The aperture 78 is in fluid communication with the stepped lumen 50 and the second opening 54. The flange 76 also serves as a restriction for the insertion of the plastic and metal tube end 46 into the through passage extending inward from the second opening 54. Preferably, the radial length of the flange 76 from the adjacent side wall of the connector body 48 has a dimension approximately equal to the thickness of the entire wall of the plastic and metal tube end 46.
[0023]
As the tube end 46 is pushed axially into engagement with the connector body 48, the tube end 46 is firmly attached. Then, the connector 48 is attached, for example, by being appropriately pressed and rotated relatively thereto. Once a suitable speed difference has been established, the tube end 46 and the connector body 48 are moved until the tip 96 of the tube end 46 contacts the flange 76, i.e., all relative axial displacement and Until the end of the rotational displacement, they are pressed together in the axial direction, as shown by arrow 98.
[0024]
During the spin welding process, the outer surface 100 of the outer layer 82 of the tube end 46 frictionally engages the inner surface of the lumen portion 79 so that these surfaces melt, and the outer surface shown best in FIG. Establish welding zone 104.
[0025]
Various control perimeters in spin welding are generally known in other applications. These are not shown here for the sake of brevity, but are not shown in U.S. Pat. No. 2,933,428 to Mueller, U.S. Pat. No. 3,980,248 to Minoshima, and U.S. Pat. No. 152,855.
[0026]
It is desirable to use a material compatible with the plastic layer 82 and the connector body 82, particularly at the melting temperature, such that they mix as expected from the molten state established during the spin welding process as they solidify. This results in a weld with optimal structural integrity.
[0027]
FIG. 5 shows a modification of the quick connector body 48 according to another embodiment of the present invention. In this embodiment, the end lumen portion 79 'extending inwardly from the second opening 54 has a constant diameter and a smooth wall configuration, as shown in FIG. , Having a first converging tapered portion 84 extending from the flange 76. This portion 84 is steeper and extends to a second tapered portion 86 that terminates in the second opening 54 of the leading projection 80.
[0028]
During the spin welding process, the steep angle of the second tapered portion 86 creates relatively high friction at the tip 96 of the tube end 46, such that the end of the plastic outer layer 82 of the tube end 46 is A large amount of heat and rapid melting occurs at the ends of the connector body 48.
[0029]
As the tube end 46 and the connector body 48 continue to be advanced axially toward each other, the plastic outer layer 82 of the tube end 46 passes through a less steep first tapered portion 84. Both the first tapered portion 84 and the second tapered portion 86 of the connector body 48 provide a complete 360 ° annular seal between the outer plastic layer 82 of the tube end 46 and the connector body 48. Provides a welding area.
[0030]
Details of the construction and use of the double tapered portion of the connector body 48, as well as a further flush trap, are described in the "Spin Welded Fluid Connector" assigned to the same assignee as the present invention. No. 6,199,916, entitled US Pat.
[0031]
To ensure a sealed connection between the plastic coated metal tube and the plastic quick connector body, use spin welding, with the other end of this connector body at the end of another tube. Unique fluid connectors that have been sealingly connected have been disclosed. The unique quick connector and fluid coupling of the present invention ensures that the metal tubing is sealingly connected to the plastic connector body, providing a full 360 ° seal between the tubing and the connector body. It is made possible by a quick spin welding process.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a spin-welded fluid coupling of the present invention.
FIG. 2 is a longitudinal sectional view of the connector main body shown in FIG.
FIG. 3 is an enlarged exploded cross-sectional view of the fluid coupling of FIG. 1 prior to spin welding a tube end into a connector body.
FIG. 4 is a greatly enlarged sectional view of a connection portion of a pipe end portion which is spin-welded to a connector main body.
FIG. 5 is a greatly enlarged sectional view of a connection portion of a pipe end portion to be spin-welded to a modified aspect of a connector body.

Claims (8)

A fluid connector for a spin weld connection having a metal tube to which an outer layer of plastic is attached, the connector comprising:
A combination comprising a body defining a through passage communicating between a first opening adapted to receive a set of conduits and a second opening adapted to receive a metal tube. The combination of claim 1 wherein the second opening defines an annular inner surface at one end of the through passage. The combination of claim 1, further comprising a flange spaced within the through passage from the second opening, extending radially inward into the through passage, and engageable with a tip of a metal tube. The combination of claim 1 further comprising a retainer mounted to the connector body for releasable engagement with the abutment surface of the set of conduits. A connector body defining a through passage interconnecting a first opening adapted to receive the conduit and a second opening opposite the second opening defining an interior surface formed in the body; The inner surface defines an inner welding surface, and
A fluid tube further comprising a metal tube having an outer layer of plastic attached thereto, which is spin welded to a weld surface inside the connector body. The fluid coupling of claim 5, wherein the second opening defines an annular inner surface at one end of the through passage. The fluid cup of claim 5, further comprising a flange spaced within the through passage from the second opening, extending radially inward into the through passage, and engageable with a tip of a metal tube. ring. The fluid coupling of claim 5, further comprising a retainer mounted to the connector body for releasable engagement with the abutment surface of the conduit.

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