FREEZE-RESISTANT QUICK CONNECTION ACCESSORY.

Abstract

A metal fitting assembly employs a clip-on body connection to lock a tube end of a fluid system component to the fitting assembly. The fitting assembly includes a fitting body that defines a fluid flow path between a first end and a second end opposite the first end, wherein the first end is configured to receive a tube end from a first fluid system component, and the fitting body defines a clip groove adjacent to the first end, and the material of the fitting body includes metal; and a clip, also made of metal. When the tube end is inserted through the first end of the fitting body, the clip engages through the clip groove and around the tube end to engage the tube end in a connected state where the tube end is locked within the fitting body.The fitting body includes a main body and an annular end that defines the clip groove between the main body and the annular end, the main body and the annular end being joined together by a bridge. For freeze resistance, the annular end is configured to minimize distortion to 0.25 mm (0.010") or less under a tensile load of 2200 Newtons (500 lbf). The ratio of the cross-sectional area of ​​the annular end to the inside diameter of the fitting body can be from 21% to 73%. The bridge can have a width within a range of 20% to 70% of the outside diameter of the fitting body.

Description

This application claims the benefit of U.S. Provisional Application No. 63 / 083,185 filed on September 25, 2020, and U.S. Provisional Application No. 63 / 111,870 filed on November 10, 2020, the contents of which are incorporated herein by reference. FIELD OF INVENTION This application relates in general to quick-connect fittings for connecting components of a fluid system, for example, quick-connect fittings for steam and liquid fuel systems or emission systems, and in particular to freeze-resistant quick-connect fittings for use in low-temperature applications. BACKGROUND OF THE INVENTION Quick-connect fittings for connecting fluid system components are used in a variety of applications for fluid transfer. These fittings work by attaching to a coupling tube end. One example is their use in steam and liquid fuel delivery systems and related emission systems that comply with the SAE J2044 standard. Example applications include diesel and gasoline fuel delivery systems and their associated evaporative emission control or venting systems. Therefore, quick-connect fittings must be able to operate under a wide variety of environmental and operating conditions, including substantial ranges of ambient and operating pressure and temperature.For example, SAE J2044 establishes operating temperature and pressure ranges for associated emission and fuel delivery systems. As the nomenclature suggests, a quick-connect fitting should be relatively easy for an operator to connect. However, conventional fitting configurations often employ threaded components that must be twisted together, which may require special tools. Connection can therefore be difficult in confined spaces. Furthermore, conventional quick-connect fittings are often made of one or more thermoplastic components, which can struggle to withstand a wide range of environmental and operating conditions. For example, when exposed to sub-zero temperatures, expanding diesel exhaust fluid can crack or rupture the thermoplastic components of the fittings. Additionally, fuel delivery and exhaust systems can operate at high temperatures that can degrade the thermoplastic components of the fittings.Consequently, conventional quick-connect fittings can be deficient in terms of ease of connection and effectiveness across a wide range of potential environmental and operating conditions. In a quick-connect fitting application, diesel emissions aftertreatment systems use aqueous urea (high-ammonia solutions) for nitrous oxide reduction. These fluids have a freezing point of approximately -10.55°C (13°F), and therefore, ambient conditions in cold climates can cause the fluid to freeze. Frozen urea expands and produces excessive stress on the hoses and fluid-carrying fittings. Conventional quick-connect fittings in such applications use SAE J2044 plastic connectors due to their chemical compatibility, ease of use, and low cost.As mentioned earlier, such conventional plastic fittings are susceptible to failure due to high stress during a fluid freezing event, and therefore conventional quick-connect fitting configurations are particularly deficient for use in low-temperature conditions. BRIEF DESCRIPTION OF THE INVENTION There is a need in the art, therefore, for an improved quick-connect fitting that is easy to connect and effective under a wide range of environmental and operating conditions, such as temperature and pressure. In exemplary embodiments, the quick-connect fitting conforms to SAE J2044 standards for steam and liquid fuel delivery systems and related emission systems. The embodiments of the present application employ an all-metal fitting design; the metallic materials have a yield strength above 1034.21 MPa (50 kpsi) and are suitable for service at high temperatures (e.g., above 93.33°C (200°F)) and low temperatures below which aqueous urea commonly used in diesel emission systems can freeze (e.g., below -10.55°C (13°F)).The all-metal design greatly increases the durability and reliability of the fitting compared to conventional configurations and is particularly suitable in conditions where the conveyed fluids can freeze and fracture the components of conventional thermoplastic fittings due to expansion. The fitting designs described in this application are therefore essentially freeze-resistant and thus overcome the shortcomings of conventional configurations while also providing effective chemical resistance and ease of use. In typical designs, the quick-connect fitting includes a metal fitting body and a metal wire / cable clip connection component used to connect the fitting body to a tube end of a fluid system component. Using a wire clip as the connection component reduces design complexity and cost, and improves ease of use. With the fitting body and clip components constructed of metal, the user has design freedom in the design and construction of the portion of the fitting body that attaches to a tube or hose. Conventional plastic materials limit this design freedom due to their lower strength. The clip attaches to the body without threaded connections and therefore does not require rotating either of the fitting components (body or clip) for assembly. This improves ease of assembly and is particularly suitable for confined spaces where rotating components is difficult with typical tools. The clip can be removed with common hand tools, such as a screwdriver or pliers that can fit the clip onto the fitting body. Therefore, this configuration does not require a dedicated removal component added to the fitting, as is common in conventional designs. The clip is lightweight and attaches to the male end of a connected tube component. Consequently, the clip does not require any additional retention or interference from the fitting body to hold it in place.In contrast, conventional fittings use stamped stainless steel parts within the fitting body to connect the tube end. Therefore, the fitting body must be specifically shaped to assemble and retain the tube connection. The ease of clip removal allows for easy access to the fitting's internal components, such as O-rings or other sealing elements, facilitating repair. Conventional fittings have stamped parts laminated into the fitting body, hindering easy maintenance. One aspect of the invention is a metal fitting assembly that is freeze-resistant and employs a clip-on body connection to lock a tube end of a fluid system component to the fitting assembly. In exemplary embodiments, the fitting assembly includes a connecting body that defines a fluid flow path between a first end and a second end opposite the first end, wherein the first end is configured to receive a tube end of a first fluid system component, and the fitting body defines a clip groove adjacent to the first end, and a material of the fitting body includes metal; and a clip wherein a material of the clip includes metal.When the tube end is inserted through the first end of the fitting body, the clip is inserted through the clip groove and around the tube end to engage the tube end in a connected state, locking it within the fitting body. The fitting body includes a main body and an annular end that defines the clip groove between the main body and the annular end. The main body and the annular end are joined together by a bridge. To be freeze-resistant, the annular end is configured to minimize distortion to 0.25 mm (0.010 in) or less under a tensile load of 2200 Newtons (500 lbf). To minimize distortion in this way, the ratio of the cross-sectional area of ​​the annular end to the inside diameter of the fitting body can range from 21% to 73%.The bridge can have a width within a range of 20% to 70% of the outer diameter of the fitting body. The clip includes first and second opposite legs extending from a cross segment, wherein in the connected state the cross segment extends through the accessory body bridge and the opposite legs extend through the clip slot.Each of the first and second legs may include a first segment extending from the cross segment; a second segment extending from the first segment in a direction away from the cross segment, wherein the second segment of the first leg and the second segment of the second leg are oppositely curved around a central point suitable for locking around the tube end; a third segment extending from the second segment in a direction away from the cross segment; and a fourth segment extending from the third segment in a direction away from the cross segment, wherein the fourth segment of the first leg and the fourth segment of the second leg are respectively flared in opposite directions from the third segment of the first leg and the third segment of the second leg.The first segments can extend from the transverse segment at substantially right angles so that the first segment of the first leg and the first segment of the second leg are parallel, and the third segments are aligned respectively with the first segments. These and other features of the present invention will be evident from the following description and accompanying drawings. In the description and drawings, particular embodiments of the invention have been described in detail as indicative of some of the ways in which the principles of the invention may be employed, but it is understood that the invention is not correspondingly limited in its scope. Rather, the invention includes all changes, modifications, and equivalents that fall within the spirit and terms of the appended claims. The features described and / or illustrated with respect to one embodiment may be used in the same or a similar manner in one or more embodiments and / or in combination with or instead of the features of the other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a drawing representing a perspective view of an exemplary accessory assembly according to the modalities of this application, showing the accessory assembly connected to one end of a tube. FIGURE 2 is a drawing that represents a perspective view of the fitting assembly and tube end of FIGURE 1 with the individual components separated. FIGURE 3 is a drawing that represents a top cross-sectional view of an accessory body component of the accessory assembly of FIGURE 1 in isolation. FIGURE 4 is a drawing that represents a close-up view of a portion of the connecting end of the tube of the fitting body of FIGURE 3. FIGURE 5 is a drawing that represents the accessory body of FIGURE 3 further connected to a housing component. FIGURE 6 is a drawing that represents a side view of a clip component of the accessory assembly in FIGURE 1 in isolation. FIGURE 7 is a drawing that represents an end view of the clip component of FIGURE 6. FIGURE 8 is a drawing that represents a non-limiting example of a close-up view of the tube-connecting end portion of the fitting body similar in shape to that depicted in FIGURE 4, which is particularly suitable for providing a freeze-resistant fitting for a low-temperature application. FIGURE 9 is a drawing showing a graphical representation of the finite element analysis results of an accessory body configuration comparable to that illustrated in FIGURE 8. DETAILED DESCRIPTION OF THE INVENTION The following sections of the present application will be described with reference to the drawings, where similar reference numbers are used to refer to similar elements throughout. It is understood that the FIGURES are not necessarily to scale. The embodiments of this application provide an improved quick-connect fitting assembly that is easy to connect and effective under a wide range of environmental and operating conditions, such as temperature and pressure. In exemplary embodiments, the quick-connect fitting assembly conforms to SAE J2044 standards for steam and liquid fuel delivery systems and related emission systems. The embodiments of this application employ an all-metal fitting assembly design; the metallic materials have a yield strength greater than 344.73 MPa (50 kpsi) and are suitable for high-temperature service (e.g., above 93.33°C (200°F)).The all-metal design greatly increases the durability and reliability of the fitting compared to conventional configurations and is particularly suitable in conditions where the conveyed fluids can freeze and fracture the components of conventional thermoplastic fittings due to expansion. The fitting assembly configurations described herein are therefore essentially freeze-resistant. Figure 1 is a perspective view drawing of an exemplary fitting assembly 10 according to the embodiments of this application. The fitting assembly 10 is shown connected to a pipe end 12. Figure 2 is a perspective view drawing of the fitting assembly 10 and the pipe end 12 of Figure 1 with the individual components separated. In exemplary embodiments, the quick-connect fitting assembly 10 includes a fitting body 14 and a wire clip connecting component 16 used to connect the fitting body 14 to the pipe end 12 of a fluid system component. The use of the wire clip 16 as the connecting component reduces design complexity and cost and improves ease of use for the user. In typical designs, both the fitting body 14 and the clip 16 are made of a metal-containing material that must be able to withstand varying operating and environmental conditions, be strong enough to withstand operating pressures, and be non-corrosive, especially for use in fuel supply and exhaust systems. Suitable materials include carbon-based materials, stainless steel, or brass, which meet the physical requirements and are cost-effective. Plated steel materials, such as nickel-plated steel, can be used in certain applications, although plated steels can be more expensive and less suitable for certain corrosive environments. With the fitting body and clip components constructed of a metal-containing material, the user has design freedom in the design and construction of the portion of the fitting body that attaches to a tube or hose.Conventional plastic materials limit this design freedom due to their lower strength. The fluid system component that includes the tube end 12 can be made of any suitable material, as is conventional in fluid flow systems, such as rigid plastic, steel or other metal, plastic-coated or plated steel, or other suitable materials commonly used in fluid system components. As detailed below, the clip is attached to the body without threaded connections and therefore does not require rotating any fitting component (body or clip) for assembly, resulting in numerous advantages over conventional configurations. Attaching the clip to the body improves ease of assembly and is particularly suitable for confined spaces where rotating components is difficult with typical tools. The clip 16 can be removed from the fitting body 14 using common hand tools, such as a screwdriver or pliers, which can either insert or remove the clip from the fitting body. Therefore, this configuration does not employ a dedicated removal component added to the fitting body, as is common in conventional configurations. The clip 16 is lightweight yet effectively retained on the male end of the connected tube component 12.The accessory assembly, therefore, does not require any additional retention or interference features built into the accessory body to hold the clip in place. The ease of clip removal, in turn, allows easy access to the internal components of the accessory assembly, such as O-rings or other sealing components, enabling easy repair of the accessory. In contrast, conventional fittings typically employ stamped stainless steel parts within the fitting body to help connect and retain the tube end. Therefore, the fitting body must be specifically shaped to assemble and retain the tube connection. Conventional fittings have stamped metal J2044 connectors or parts rolled into place with the fitting body, hindering easy maintenance. Such all-metal, rolled body designs cannot be disassembled with common hand tools. Many conventional configurations also use plastic spacers and a plastic retainer for the O-rings.The modalities of the present application include only two retaining components (body and clip) that receive the O-ring seals, thus preventing the possibility of the O-ring retaining components coming out of place during a hard freeze due to the expansion of the diesel exhaust fluid. The fitting body 14 includes a first end 18 and a second end 20 opposite the first end 18. The first end 18 is configured to receive the tube end 12. As detailed below, when the tube end 12 is inserted through the first end 18 of the fitting body 14, the clip 16 engages with the tube end 12 and the fitting body 14, locking the tube end 12 within the fitting body 14, referred to as the connected state. In this example, an outer surface of the fitting body 14 is stepped, although the fitting body 14 can have any shape suitable for a particular application. In the example, as depicted in Figures 1 and 2, the second end 20 of the fitting body 14 is configured as a nozzle to receive a hose or similar component. The second end of the nozzle 20 is configured with a plurality of ribs 22.When a hose is pushed onto the second end 20, the ribs 22 help retain the hose in the fitting assembly. Although in this example the second end 20 is configured as a ribbed nozzle to receive a hose, other types of fluid connections can be used as the second end 20 as appropriate for any particular application. Figure 3 is a drawing that represents a top cross-sectional view of component 14 of the fitting body of fitting assembly 10 in Figure 1 in isolation. Figure 4 is a drawing that represents a close-up view of a pipe connection end portion 24 of fitting body 14 in Figure 3. Referring to Figures 1 through 4 in combination, the pipe connection end portion 24 is attached to the first end 18 of the fitting body. The fitting body 14 defines a fluid flow path 26 for the passage of a fluid between the first end 18 and the second end 20. The fitting body includes a main body 28 and an annular end 30 that is joined to the main body 28 via a bridge 32. The main body 28 and the annular end 30 define a clip slot 34 that receives the clip 16, as best seen in the connected state depicted in FIGURE 1. To secure the tube end 12 to the fitting assembly 10, the tube end 12 is inserted through the first end 18 of the fitting body 14 into the second end 20. The tube end 12 may include an interaction element / feature 13, such as one or more ridges or protrusions 13 (see particularly the separate view in FIGURE 2), which can interact with the clip 16. The tube end is inserted far enough so that any interaction element 13 of the tube end 12 is located beyond the clip slot 34 relative to the first end 18 of the fitting body 14. Once the tube end is positioned as such, the clip 16 is inserted through the clip slot 34. Further details of the structure and operation of the clip 16 are described below in relation to the subsequent figures.In general, clip 16 includes opposing legs 36 and 38 extending from a cross segment 40 (see FIGURES 1 and 2). Legs 36 and 38 form substantially right angles (e.g., 90°±10°) with the cross segment 40 where the respective legs and the cross segment meet. In the connected state as shown in FIGURE 1, the cross segment 40 extends through the bridge 32 of the fitting body 14. The clip legs 36 and 38 extend through the clip groove 34, and the clip is thus held in place within the clip groove between the main body 28 and the annular end 30 of the fitting body 14. The legs are configured for a tight fit against an outer surface of the tube end 12, with any interacting element 13 of the tube end 12 being farthest from the first end 18 relative to the clip 16.In this way, the interaction of the clip legs 36 and 38 against the interaction element (crest) 13 of the tube end 12 prevents the tube end from coming out of the fitting body 14. To form the clip groove 34 while providing a surface to support the clip 16, the bridge 32 is configured as a partial portion of the fitting body 14 relative to the main body 28 and the annular end 30. In other words, the bridge 32 extends substantially less than the circumference or perimeter of the wider fitting body components to allow the clip 16 to be inserted through the clip groove 34 so that it locks the tube end 12 within the fitting body as described above. The bridge 32 could therefore potentially constitute a weak point and a potential failure point in the fitting assembly if the fitting body were made of a plastic material such as that used in many conventional configurations.Because the fitting body 14, including the bridge 32, is made of a metal-based material, the bridge 32 is strong enough to allow the tube end to be locked without weakness or failure. Consequently, conventional thermoplastic materials may have insufficient strength to accommodate the clip's attachment to the fitting assembly body 10, as an analogous thermoplastic bridge could break under the forces associated with locking the tube end 12 with the clip 16. With particular reference to FIGURES 3 and 4, an inner diameter 41 of the fitting body 14 may include one or more sealing grooves machined into the inner diameter of the fitting body. In the illustrated example, two sealing grooves 42 and 44 are provided, and each sealing groove may receive a respective sealing element, such as O-rings 43 and 45 (see FIGURE 5). The sealing elements prevent fluid leakage between an outer surface of the pipe end 12 and the inner diameter 41 of the fitting body 14 in the connected state. Alternatively, the inner diameter 41 may be constant, and sealing is achieved by inserting a dedicated sealing element into the fitting body.A sealing element of this type can be configured as a press-fit frame made of a suitable rigid material, incorporating one or more sealing components (e.g., O-rings) within the frame. This sealing element is therefore press-fitted into the fitting body in such a way that it provides a comparable seal against fluid leakage between an outer surface of the tube end 12 and the inner diameter 41 of the fitting body 14. Figure 5 is a drawing depicting the fitting body 14 of Figure 3 further connected to a housing component 46. The housing component 46 is particularly used in applications where the second end 20 of the fitting body is specifically configured as a ribbed fitting to receive a hose. The housing component 46 may be made of metal-based materials, unlike the fitting body 14. The fitting body 14 includes a shoulder 48, and the housing component 46 includes an opposing shoulder 50, which interact with each other to retain the housing connected to the fitting body. During assembly, the housing 46 simply slides onto the fitting body 14 to align the opposing shoulders 48 and 50. Figure 5 illustrates an initial assembly state.In this initial state, the housing component 46 widens radially outwards from the opposite shoulder 50, so that the ribbed surface of the nozzle end 20 of the fitting body and an inner surface of the housing 46 define a hose receiving space 52. In addition, the inner surface of the housing component 46 includes a plurality of prongs 54. To connect a hose to the fitting assembly 10, the hose (not shown) is forced over the second end of the ribbed nozzle 20 of the fitting body 14. The hose is therefore located within the hose receiving space 52 and is partially retained by the ribs 22. The housing component 46 is then crimped onto the hose using a suitable crimping tool, as known in the art, and the prongs 54 bite into the outer surface of the hose to form a tight connection of the hose with the fitting assembly 10. As mentioned previously, to secure the pipe end 12 to the fitting assembly 10, the pipe end 12 is inserted through the first end 18 of the fitting body 14, and the clip 16 is used to lock the pipe end within the fitting body 14. Figure 6 is a drawing depicting a side view of the clip component 16 of the isolated fitting assembly 10 in Figure 1. As also mentioned previously, the clip 16 includes opposing legs 36 and 38 extending from a cross segment 40. Furthermore, legs 36 and 38 form substantially right angles (e.g., 90° ± 10°) with the cross segment 40 where the respective legs and the cross segment meet. As illustrated in the example in FIGURE 6, each of legs 36 and 38 can be divided into a plurality of segments, and in the example shown, the segments are mirror images of each other; that is, the segments of the first leg 36 are mirror images of the segments of the second leg 38. In one exemplary configuration, the first segments 60a / 60b extend from the transverse segment 40 at the substantially right angle mentioned above. Consequently, looking at the legs individually, the first segment 60a of the first leg 36 and the first segment 60b of the second leg 38 are essentially parallel to each other. The second segments 62a / 62b extend from the first segments 60a / 60b in the opposite direction to the transverse segment 40.The second segments 62a / 62b are curved segments having a radius of curvature around a central point “+” identified in FIGURE 6, suitable for locking around the tube end 12 configured for any particular application. Accordingly, looking at the legs individually, the second segment 62a of the first leg 36 and the second segment 62b of the second leg 38 have opposite curvatures so that together the second segments encompass or surround and thus lock the tube end 12 within the fitting body 14 when it is in the connected state. The third segments 64a / 64b extend from the second segments in a direction away from the cross segment 40 and also at substantially right angles to the aforementioned cross segment.Therefore, considering the legs individually, the third segment 64a of the first leg 36 and the third segment 64b of the second leg 38 are essentially parallel to each other, and are also essentially aligned with the first segments 60a / 60b. The fourth segments 66a / 66b extend from the third segments in a direction away from the transverse segment, and the fourth segments 66a / 66b are flared outwards relative to the third segments. Consequently, considering the legs individually, the fourth segment 66a of the first leg 36 and the fourth segment 66b of the second leg 38 flare in opposite directions and away from each other. Any suitable angle of flare may be used.In general, the flare angle should be large enough to promote the extension of the clip when it is pressed into place around the end of the tube for mounting, as too small an angle can cause the legs to damage the male end of the tube if the tips of the clip legs dig into the tube end. FIGURE 7 is a drawing representing an end view of clip component 16 of FIGURE 6. As shown in FIGURES 6 and 7, the quarter and flared segments 66a and 66b terminate respectively at a first clip end 70 and a second clip end 72. As shown in FIGURE 7, the clip legs 36 and 38 flare from the clip ends 70 and 12 toward the cross segment 40. Referring to FIGURES 1 and 2 in combination with FIGURES 6 and 7, the tube end 12 is connected to the fitting assembly 10 as follows. As mentioned previously, the tube end 12 is inserted through the first end 18 of the fitting body 14 into the second end 20 far enough so that the interaction element (ridge) 13 of the tube end is located beyond the clip groove 34 relative to the first end 18 of the fitting body. Once the tube end is positioned as such, the clip 16 is inserted through the clip groove 34. The flared quarter segments 66a and 66b of the clip 16 assist in clip insertion. The clip legs 36 and 38 act as a spring that deflects into a native position, as illustrated in the isolated view of FIGURE 6.As clip 16 is pressed through clip slot 34 into a locked position, a wedging action of tube end 12 against the flared quarter segments 66a and 66b separates clip legs 36 and 38 so that the clip can be inserted around the tube end. 12 As mentioned above, the legs of clip 36 and 38 widen from the ends of clip 70 and 72 toward the cross segment 40. This helps to separate the legs of the clip as the clip is inserted through the clip slot 34 and around the end of tube 12. The clip is inserted through the clip slot 34 until the end of tube 32 rests between the third curved segments 64a and 64b, and the angle of clip 16 provides a firm grip on the end of tube 12, with the interaction with the ridge 13 of the end of tube 12 locking the end of tube 12 in place.The cross segment 40 that interacts against the bridge 32 of the accessory body 14 prevents further insertion of the clip 16 through the clip sliding groove 34. As mentioned previously, in the connected state as shown in FIGURE 1, the cross segment 40 of clip 16 extends across the bridge 32 of the fitting body 14. Clip 16 is held in place within the clip groove 34 between the main body 28 and the annular end 30 of the fitting body 14, and the interaction of the interaction element 13 of the tube end 12 with the clip legs 36 and 38 prevents the tube end from coming out of the fitting body 14. Furthermore, the widening of the clip legs 36 and 38 in a direction from the clip ends 70 and 72 toward the cross segment 40, with the cross segment 40 being the widest portion of clip 16, results in a strong clamping of clip 16 against the bridge 32 of the fitting body 14 to prevent the clip from breaking at the cross segment when the clip interacts against the bridge 32 to lock the tube end in place. place. Clip 16 can be removed from the fitting body 14 using common hand tools, such as a screwdriver or pliers, which can wedge or pry the clip out of the fitting body 14. Specifically, a wedging action of the tool can separate legs 36 and 38 against clip deflection, and the legs can be pushed past the tube end along the clip groove until the clip is removed. Therefore, the configuration does not employ a dedicated removal component added to the fitting body as is common in conventional configurations. Once clip 16 is removed, the tube end 12 can be pulled out of the fitting body 14. Figure 8 is a drawing that represents a non-limiting example of a close-up view of a 24-tube fitting body end portion similar to that shown in Figure 4, and is particularly suitable for providing a freeze-resistant fitting configuration for a low-temperature application. It will be appreciated that Figure 8 represents a particular example, and suitable variations may be employed for particular applications. As mentioned earlier, in a quick-connect fitting application, diesel emissions aftertreatment systems use aqueous urea (high-ammonia solutions) for nitrous oxide reduction. These fluids have a freezing point of approximately -10.55°C (13°F), and therefore, ambient conditions in cold climates can cause the fluid to freeze.Frozen urea expands and produces excessive forces on fluid transport hoses and fittings, and the example in FIGURE 8 provides a configuration designed to be freeze-resistant to prevent fitting failure under such conditions. Referring to the example in FIGURE 8, D1 indicates an inside diameter of the fitting body 14, which again includes the main body 28 and the annular end 30 connected by the bridge 32. D2 indicates an outside diameter of the fitting body 14. W1 denotes a longitudinal dimension of the annular end 30 (i.e., the dimension in the direction of fluid flow), and W2 denotes a width dimension of the annular end 30 perpendicular to W1 (i.e., the dimension perpendicular to the direction of fluid flow). Consequently, the annular end 30 has a cross-sectional area of ​​W1 x W2. W3 denotes a width dimension of the bridge 32, and S1 denotes a longitudinal dimension (in the direction of fluid flow) of the clip groove 34 defined between the main body 28 and the annular end 30. The dimensions in the example are shown in inches in FIGURE 8 for illustrative purposes. The SAE J2044 / J2045 specifications require a minimum tensile strength of 450 N (101 lbf) at 23°C (ambient temperature). However, field performance and laboratory testing have determined that this specification is inadequate to prevent fitting failure due to fluid freezing. Laboratory testing has determined that a fitting tensile strength of at least 2200 Newtons (500 lbf) is preferred to prevent freeze failure, which typically occurs with plastic fitting distortion exceeding 5% in glass-filled polymers. To design a fitting body that meets the conditions to be considered freeze-resistant, the following design elements are optimized according to the modalities of this application.(1) Fitting Material: The fitting material is selected for its strength to prevent freeze-thaw failure and its chemical resistance to corrosion, which can be a problem, for example, in diesel emission treatment systems. (2) Fitting Diameter: The inside and outside diameters of the fitting body are selected for the appropriate size and match the corresponding SAE J2044 pipe end dimensions and minimized to provide maximum space for installation.(3) Bridge configuration: The bridge (element 32 in the figures) is configured to meet the strength requirements necessary to be freeze-resistant; (4) Annular end: The annular end (element 30 in the figures), which receives the focus of the tensile load during a freeze-up event or a tensile test, is configured to meet the strength requirements necessary to be freeze-resistant. Regarding the fitting material, stainless steel is a suitable choice because it resists corrosion and degradation from urea solutions and has sufficient strength to prevent distortion under much higher loads compared to conventional glass-filled plastics (15-30%) (polyamides, PPA). Brass and plated carbon steel may not be suitable for diesel emission system applications due to their poor resistance to urea corrosion, but they could potentially be used for freeze resistance in other applications that may not present corrosion problems. The material properties of stainless steel are generally approximately as follows: modulus: 193053.2 MPa (28000 ksi), tensile strength: 503.31 MPa (73000 psi), and yield strength: 213.73 MPa (31000 psi).In contrast, a typical 12-30% nylon fiberglass-filled polymer has the following properties: modulus: 6494.86 MPa (942 ksi) and a tensile strength of 119968.78 MPa (17400 psi) with only 5% deformation at break. Such properties would generally not be sufficient to provide such freeze resistance. Regarding the fitting's inside and outside diameters, for specific applications according to J2044, the fitting's outside diameter D2 is restricted to a range between 12.7 mm (1 / 2") and 19 mm (3 / 4") to match the size requirements for the corresponding SAE J2044 pipe fitting dimensions and to maintain a small profile for ease of installation and to prevent crowding when two or more fittings are installed side-by-side. The SAE J2044 pipe fitting sizes primarily used include 6.3 mm (1 / 1"), 7.9 mm (5 / 16"), and 9.5 mm (3 / 8") in diameter(s), and the reference range of the D2 outside diameter is sized to accommodate a corresponding pipe fitting size. The fitting's inside diameter is selected in relation to the specific SAE J2044 pipe fitting size being used and the corresponding specified stub diameter, as known in the art.In general, as is known in the art, the inner diameter D1 is equal to the bead diameter plus 0.4mm (0.015”) to 1mm (0.039”) to obtain sufficient clearance for assembly and insertion. Regarding the bridge configuration, in typical designs, the bridge width W3 is within a range of 20% to 70% of the fitting body's outside diameter D1 to allow for proper spacing and alignment of the wire clip 16 to provide an effective coupling with the SAE J2044 male pipe fitting. A bridge width W3 less than 20% of the fitting body's outside diameter D1 may not provide sufficient tensile strength to be freeze-resistant, and a bridge width W3 greater than approximately 70% of the fitting body's outside diameter D1 may not provide sufficient clearance for effective installation of the wire clip 16. For example, for a fitting designed for a 9.5 mm (3 / 8") SAE J2044 pipe fitting, the bridge width W3 would be between 2.7 mm (0.100") and 9.6 mm (0.375"). Regarding the annular end configuration, finite element analysis (FEA) and laboratory testing have determined that the annular end experiences the highest level of distortion or deformation during a freeze-thaw event. Consequently, to prevent significant failure or distortion during a freeze-thaw event, the annular end is configured to minimize distortion to 0.25 mm (0.010 in) or less at the target tensile load of 2200 Newtons (500 lbf) that occurs during a urea freeze-thaw event. To meet this requirement, the ring end is configured to have a minimum cross-sectional area (W1 x W2) of 2.9 mm² (0.0045 sq in) for a 9.5 mm (3 / 8 in) SAE J2044 male fitting. Minimizing fitting distortion to 0.25 mm (0.010 in).A diameter of 0.010” or less allows the fitting to maintain the functional sealing requirements and the ability to detach and reassemble the fitting for system maintenance and / or repair. More generally, when normalizing the cross-sectional area of ​​the annular end relative to the fitting's inside diameter D1, the ratio of the annular end cross-sectional area to the fitting body's inside diameter D1 should be between 21% and 73%. For example, applying this normalization to a 9.5 mm (3 / 8”) SAE J2044 male fitting results in a minimum ratio of 0.212 or 2.9 / 13.7. To avoid fitting installation problems while meeting these ratio parameters, the longitudinal dimension W1 of the annular end can be restricted to approximately 10 mm (0.400”), and this results in the width dimension W2 being sized to achieve a maximum area ratio (W1xW2) / D1 of 0.729 = 10 / 13.7. The design parameters were investigated using FEA to determine the effectiveness of configurations comparable to those previously established. Figure 9 is a drawing showing a graphical representation of the FEA results, which are presented in the following table. As shown by the FEA results, the annular end experiences the highest level of distortion during tensile loading. FEA iterations were performed to determine the cross-sectional area dimension of the stainless steel annular end required to withstand a displacement of 0.25 mm (0.010 in) under a load of 2200 Newtons (500 lbf). The FEA results verify that a suitable ring cross-sectional area should be 21% or more of the outside diameter of the fitting body D1 to achieve a freeze-resistant configuration. Case 1 2 3 4 5 6 7 8 Size SAE 3 / 8 3 / 8 3 / 8 3 / 8 3 / 8 3 / 8 3 / 8 3 / 8 D1 13.7mm 13.7mm 13.7mm 13.7mm 13.7mm 13.7mm 13.7mm 13.7mm W / in. .050 1.27 .050 1.27 .075 1.9 .089 2.25 .100 2.5 .125 3.2 .083 2.1 .150 3.8 W2 (inches / mm) .050 1.27 .050 1.27 .075 .050 1.27 .050 1.27 .050 1.27 .075 1.9 .050 1.27 (CS) Cross section (inches / mm) 0.0025 3.2 0.0062 5 4.1 0.0062 3 4.0 0.0075 4.8 W3 (inches / mm) 0.110 (30 % R) .225 (60 % R) .225 (60 % R) .225 (60 % R) 25.25 R. (60 % R) .225 (60 % R) .225 (60 % R) Ratio: CS / D1 (%) 11.7 % 11.7 % 17.5 % 21.2 % 23.4 % 29.9 % 29.2 % 35 min.0 % SAE (749 % N. Ibf) 0.0097 0.0059 0.0025 0.0019 0.0015 0.0010 0.0014 0.0007 889.64N (200 Ibf) 0.0195 0.0119 0.0050 0.0029 0.0029 0.0028 0.0015 2224.11N (500 Ibf) 0.0125 .0097 0.0073 0.0052 0.0070 0.0039 4448.22N (1000 Ibf) 0.0104 0.01040 807 One aspect of the invention is a metal fitting assembly that is freeze-resistant and employs a clip-on body connection to lock a tube end of a fluid system component to the fitting assembly. In exemplary embodiments, the fitting assembly includes a connecting body that defines a fluid flow path between a first end and a second end opposite the first end, wherein the first end is configured to receive a tube end of a first fluid system component, and the fitting body defines a clip groove adjacent to the first end, and a material of the fitting body includes metal; and a clip wherein a material of the clip includes metal.When the tube end is inserted through the first end of the fitting body, the clip is inserted through the clip groove and around the tube end to engage the tube end in a connected state, locking it within the fitting body. The fitting body includes a main body and an annular end that defines the clip groove between the main body and the annular end. The fitting body also includes a bridge, and the main body and annular end are joined together by the bridge. To be freeze-resistant, the annular end is configured to minimize distortion to 0.25 mm (0.010 in) or less under a tensile load of 2200 Newtons (500 lbf). The fitting assembly may include one or more of the following features, either individually or in combination. In one example embodiment of the fitting assembly, the ratio of the cross-sectional area of ​​the annular end to the inside diameter of the fitting body is 21% to 73%. In one example embodiment of the fitting assembly, the fitting assembly is configured to connect to a 9.5mm (3 / 8”) SAE J2044 male terminal, and the ratio of the annular end cross-sectional area to the fitting body inside diameter has a minimum ratio of 0.212 and a maximum ratio of 0.729. In an exemplary form of accessory assembly, the end of the ring has a longitudinal dimension of 10mm (0.400”). In an exemplary form of accessory assembly, the bridge has a width within a range of 20% to 70% of the outside diameter of the accessory body. In an exemplary embodiment of the accessory assembly, the clip includes first and second opposite legs extending from a cross segment, where in the connected state the cross segment extends through the accessory body bridge and the opposite legs extend through the clip slot. In an exemplary embodiment of the accessory assembly, each of the first and second opposite legs of the clip comprises: a first segment extending from the cross segment; a second segment extending from the first segment in a direction away from the cross segment, wherein the second segment of the first leg and the second segment of the second leg are oppositely curved around a central point suitable for locking around the tube end; a third segment extending from the second segment in a direction away from the cross segment; and a fourth segment extending from the third segment in a direction away from the cross segment, and the fourth segment of the first leg and the fourth segment of the second leg respectively are flared in opposite directions from the third segment of the first leg and the third segment of the second leg. In an exemplary form of accessory assembly, the first segments extend from the cross segment at substantially right angles, so that the first segment of the first leg and the first segment of the second leg are parallel, and the third segments are respectively aligned with the first segments. In an exemplary embodiment of the accessory assembly, the first leg terminates in a first clip end and the second leg terminates in a second clip end, and the first and second legs widen from the first and second clip ends toward the cross segment. In an exemplary form of accessory assembly, the segments of the first leg are a mirror image of the segments of the second leg. In an exemplary form of accessory assembly, the accessory body and / or clip are made of stainless steel. In an exemplary form of accessory assembly, the accessory assembly complies with SAE J2044 standards. In an exemplary embodiment of the fitting assembly, the fitting assembly further includes a sealing element that seals against an outer surface of the tube end in the connected state. In one exemplary embodiment of the fitting assembly, an inner diameter of the sealing body includes a groove, and the sealing element is an O-ring that is placed inside the groove. In an exemplary form of accessory assembly, the metallic materials of the accessory body and clip have a yield strength exceeding 1034.21 MPa (50 kpsi). In an exemplary form of accessory assembly, the second end of the accessory body is configured to connect to a second fluid system component. In an exemplary form of accessory assembly, the second end of the accessory body is a ribbed nozzle configured to receive a hose. In an exemplary form of the fitting assembly, the fitting assembly further includes a housing that is connected to the second end of the fitting body, where the nozzle and housing define a space to receive the hose, and the housing is crimped around the hose to connect the hose to the fitting assembly. Although the invention has been shown and described with respect to a particular embodiment or embodiments, it is evident that other individuals skilled in the art will devise equivalent alterations and modifications after reading and understanding this specification and the accompanying drawings. In particular, with respect to the various functions performed by the elements described above (components, assemblies, devices, compositions, etc.), the terms (including a reference to a means) used to describe these elements are intended, unless otherwise indicated, to correspond to any element that performs the specified function of the described element (i.e., is functionally equivalent), even if it is not structurally equivalent to the described structure that performs the function in the exemplary embodiment or embodiments of the invention illustrated herein.Furthermore, although a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more features of the other embodiments, as desired and advantageous for any given or particular application.

Claims

1. An accessory assembly for connecting components of a fluid system, the accessory assembly being characterized in that it comprises: an accessory body defining a fluid flow path between a first end and a second end opposite the first end, wherein the first end is configured to receive a tube end of a first fluid system component, and the accessory body defines a clip groove adjacent to the first end, and a material of the accessory body includes metal; and a clip wherein a material of the clip includes metal, and when the tube end is inserted through the first end of the accessory body, the clip is inserted through the clip groove and around the tube end to engage the tube end in a connected state in which the tube end is locked within the accessory body;wherein the accessory body includes a main body and an annular end defining the clip groove between the main body and the annular end, the accessory body further includes a bridge, and the main body and the annular end are joined together by the bridge; and wherein the annular end is configured to minimize distortion to 0.25 mm (0.010”) or less at a tensile load of 2200 Newtons (500 lbf).

2. The accessory assembly according to claim 1, characterized in that the ratio between the cross-sectional area of ​​the annular end and the inner diameter of the accessory body ranges from 21% to 73%.

3. The fitting assembly according to claim 2, characterized in that the fitting assembly is configured to connect to a 9.5mm (3 / 8”) SAE J2044 male terminal, and the ratio between the cross-sectional area of ​​the annular end and the inside diameter of the fitting body has a minimum ratio of 0.212 and a maximum ratio of 0.

729.

4. The accessory assembly according to claim 3, characterized in that the annular end has a longitudinal dimension of 10mm (0.400”).

5. The accessory assembly according to any of claims 1 to 4, characterized in that the bridge has a width within a range of 20% to 70% of the outside diameter of the accessory body.

6. The accessory assembly according to any of claims 1 to 5, characterized in that the clip includes first and second opposite legs extending from a cross segment, wherein in the connected state, the cross segment extends through the bridge of the accessory body and the opposite legs extend through the clip slot.

7. The accessory assembly according to claim 6, characterized in that each of the first and second opposite legs of the clip comprises: a first segment extending from the cross segment; a second segment extending from the first segment in a direction away from the cross segment, wherein the second segment of the first leg and the second segment of the second leg are oppositely curved about a center point suitable for locking around the tube end; a third segment extending from the second segment in a direction away from the cross segment; and a fourth segment extending from the third segment in a direction away from the cross segment, and the fourth segment of the first leg and the fourth segment of the second leg are respectively flared in opposite directions from the third segment of the first leg and the third segment of the second leg.

8. The accessory assembly according to claim 7, characterized in that the first segments extend from the cross segment at substantially right angles, such that the first segment of the first leg and the first segment of the second leg are parallel, and the third segments are respectively aligned with the first segments 9. The accessory assembly according to any of claims 6 to 8, characterized in that the first leg terminates in a first clip end and the second leg terminates in a second clip end, and the first and second legs widen from the first and second clip ends into the cross segment.

10. The accessory assembly according to any of claims 7 to 9, characterized in that the segments of the first leg are a mirror image of the segments of the second leg.

11. The accessory assembly according to any of claims 1 to 10, characterized in that the accessory body and / or the clip are made of stainless steel.

12. The accessory assembly according to any of claims 1 to 11, characterized in that the accessory assembly conforms to SAE J2044 standards.

13. The fitting assembly according to any of claims 1 to 12, characterized in that it further comprises a sealing element that seals against an outer surface of the tube end in the connected state.

14. The accessory assembly according to claim 13, characterized in that an inner diameter of the sealing body includes a groove, and the sealing element is an O-ring that is placed inside the groove.

15. The accessory assembly according to any of claims 1 to 14, characterized in that the metallic materials of the accessory body and the clip have a yield strength greater than 1034.21 MPa (50 kpsi).

16. The accessory assembly according to any of claims 1 to 15, characterized in that the second end of the accessory body is configured to connect to a second fluid system component.

17. The accessory assembly according to claim 16, characterized in that the second end of the accessory body is a ribbed nozzle configured to receive a hose.

18. The accessory assembly according to claim 17, characterized in that it further comprises a housing that is connected to the second end of the accessory body, wherein the nozzle and the housing define a space for receiving the hose, and the housing is folded around the hose to connect the hose to the accessory assembly.

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