Freeze-resistant quick-connect fittings

Abstract

A metallic fitting assembly employs a clip-to-body attachment for locking a tube end 12 of a fluid system component into the fitting assembly. The fitting assembly 10 includes: a fitting body 14 defining a fluid flow path 26 between a first end and a second end opposite the first end, the first end configured to receive a tube end 12 of a first fluid system component, the fitting body 14 defining a clip slot 34 adjacent the first end, the fitting body being made of a metal; and a clip 16, the clip being made of a metal. When the tube end 12 is inserted into the first end of the fitting body 14, the clip 16 is inserted through the clip slot 34 and around the tube end 12, thereby engaging the tube end 12 in a locked connection within the fitting body 14. The fitting body 14 includes a main body 28 and a ringed end 30 that defines a clip slot 34 between the main body 28 and the ringed end 30, the main body 28 and the ringed end 30 being attached to one another by a bridge 32. For freeze resistance, the ringed end 30 is configured to minimize distortion to 0.010 inches (0.25 mm) or less at a tensile load of 500 lbf (2200 Newtons). The ratio of the cross-sectional area of ​​the ringed end to the inner diameter of the fitting body may be 21% to 73%. The bridge 30 may have a width that is 20% to 70% of the outer diameter of the fitting body.

Description

Technical Field

[0001] Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 083,185, filed Sep. 25, 2020, and U.S. Provisional Patent Application No. 63 / 111,870, filed Nov. 10, 2020, the contents of which are incorporated herein by reference.

[0002] This application generally relates to quick-connect fittings for connecting components of fluid systems, such as quick-connect fittings for liquid fuel and vapor systems or exhaust systems, and particularly to freeze-resistant quick-connect fittings for use in low-temperature applications.

Background Art

[0003] Quick-connect fittings for connecting components of fluid systems are used in a variety of applications for the transfer of fluid through the system. Quick-connect fittings operate by joining the fitting to mating tube ends. One example is the use of quick-connect fittings for liquid fuel and vapor delivery systems and associated exhaust systems that conform to SAE J2044 standards. Exemplary applications include gasoline and diesel fuel delivery systems and associated venting or evaporative emissions systems. Thus, quick-connect fittings need to be able to operate under a variety of environmental and operating conditions, including a substantial range of operating and ambient temperatures and pressure conditions. For example, SAE J2044 describes temperature and pressure operating ranges for associated fuel delivery and exhaust systems.

Summary of the Invention

Problems to be Solved by the Invention

[0004] "Quick" connectors, as the name suggests, need to be relatively easy for operators to connect. However, conventional connectors often employ threaded components that need to be rotated relative to each other, which may require specialized tools. Furthermore, conventional quick connectors are often made from one or more thermoplastic components, which can make them unsuitable for diverse environmental and operating conditions. For example, when exposed to sub-zero conditions, the expansion of diesel exhaust fluid can cause thermoplastic connector components to crack or break. In addition, fuel delivery and exhaust systems may operate at high temperatures that can degrade thermoplastic components. Therefore, conventional quick connectors may be insufficient in terms of ease of connection and effectiveness across a variety of possible environmental and operating conditions.

[0005] In one application of quick-connect fittings, diesel after-treatment emission systems use liquid urea (a high-ammonia solution) to reduce nitrous oxide. Since the freezing point of these fluids is approximately 13°F, they can freeze in cold environmental conditions. When urea freezes, it expands, generating excessive force on the fluid transport hose and fittings. Conventional quick-connect fittings for such applications utilize plastic SAE J2044 connectors due to their chemical resistance, ease of use, and low cost. However, as mentioned above, such conventional plastic fittings are prone to failure due to the high tensile loads when the fluid freezes, making the configuration of conventional quick-connect fittings insufficient, especially for use in low-temperature conditions. [Means for solving the problem]

[0006] Therefore, there is a demand in the art for enhanced quick-connect fittings that are easy to connect and effective across a wide range of environmental and operating conditions, including temperature and pressure. In exemplary embodiments, the quick-connect fitting conforms to the SAE J2044 standard for liquid fuel and vapor delivery systems and associated exhaust systems. Embodiments of the present application employ an all-metal fitting design, the metal material having a yield strength of over 50 kpsi, and is suitable for operation at high temperatures (e.g., above 200°F) and low temperatures (e.g., below 13°F) below which liquid urea commonly used in diesel exhaust systems can freeze. This all-metal design significantly improves the durability and reliability of the fitting compared to conventional configurations and is particularly suitable under conditions where the delivered fluid may freeze and expand, potentially fracturing conventional thermoplastic fitting components. Thus, embodiments of the fitting of the present application are inherently freeze-resistant, thus overcoming the shortcomings of conventional configurations while still providing effective chemical resistance and ease of use.

[0007] In an exemplary embodiment, the quick-connect fitting includes a metal fitting body and a metal wire clip connector used to connect the fitting body to the end of a tube in a fluid system component. Using a wire clip as a connector reduces design complexity and cost, and improves ease of use for the user. Because the fitting body and the clip are made of metal, the user has design freedom regarding the design and configuration of the portion of the fitting body that attaches to a tube or hose. With conventional plastic materials, this design freedom is limited due to the relatively low strength of such plastic materials.

[0008] Clip-to-body attachments do not use screw connections, and therefore do not require rotation of any fitting component (body or clip) for assembly. This improves ease of assembly and is particularly suitable for confined spaces where it is difficult to achieve rotation of the components using typical tools. The clip can be removed with common hand tools such as a screwdriver or pliers that can push the clip out of the fitting body, so the configuration does not employ any dedicated removal parts added to the fitting, as is common in conventional configurations. The clip is lightweight and is held in place by the male end of the connected tube component. Therefore, the clip does not require any additional holding or interference from the fitting body to maintain the clip in place. In contrast, conventional fittings use a stainless steel piece punched inside the fitting body to assist in connecting the tube end, so the fitting body needs to be specially formed for assembly and holding the tube connection. Furthermore, the ease of removing the clip facilitates access to the internal components of the fitting, such as O-rings or other sealing components, thereby facilitating maintenance of the fitting. Conventional fittings have a stamped piece that is rolled into place by the fitting body, which hinders easy maintenance.

[0009] One aspect of the present invention is a metal fitting assembly, the metal fitting assembly being freeze-resistant, and employing a clip-to-body attachment for locking a tube end of a fluid system component to the fitting assembly. In an exemplary embodiment, the fitting assembly includes: a fitting body defining a fluid passage between a first end and a second end opposite to the first end, the first end being configured to receive a tube end of a first fluid system component, the fitting body defining a clip slot adjacent to the first end, the material of the fitting body being metal; and a clip, the material of the clip being metal. When inserting the tube end into the first end of the fitting body, the clip is inserted around the tube end through the clip slot, thereby engaging the tube end in a locked connection within the fitting body. The above-described joint body includes a main body and a ring-shaped end that defines the clip slot between the main body and the ring-shaped end, and the main body and the ring-shaped end are attached to each other by a bridge. For freeze resistance, the ring-shaped end is configured to minimize strain to 0.010 inches (0.25 mm) or less at a tensile load of 500 lbf (2200 Newtons). To minimize strain in this way, the ratio of the cross-sectional area of ​​the ring-shaped end to the inner diameter of the joint body is 21%. (mm 2 / mm) ~73% (mm 2 / mm) This is possible. The bridge may have a width of 20% to 70% of the outer diameter of the joint body.

[0010] The clip includes first and second opposing legs extending from a lateral segment, wherein in the connected state, the lateral segment extends across the bridge of the joint body, and the opposing legs extend through the clip slot. The first leg and the second leg each comprise: a first segment extending from the lateral segment; a second segment extending from the first segment away from the lateral segment, wherein the second segment of the first leg and the second segment of the second leg curve in opposite directions around a midpoint suitable for locking around the end of the tube; a third segment extending from the second segment away from the lateral segment; and a fourth segment extending from the third segment away from the lateral segment, wherein the fourth segment of the first leg and the fourth segment of the second leg each comprise a fourth segment flaring out in opposite directions from the third segment of the first leg and the third segment of the second leg. The first segment described above may extend approximately perpendicularly from the lateral segment such that the first segment of the first leg and the first segment of the second leg are parallel, and the third segment is aligned with the first segment.

[0011] These and further features of the present invention will become apparent with reference to the following description and accompanying drawings. In this description and drawings, certain embodiments of the present invention are disclosed in detail as illustrating some ways in which the principles of the present invention can be employed, but it will be understood that the scope of the present invention is not correspondingly limited thereto. Rather, the present invention includes all changes, modifications and equivalents within the spirit and scope of the accompanying claims. Features described and / or illustrated in reference to one embodiment can be used in the same or similar manner in one or more other embodiments, and / or in combination with or in place of features of the other embodiments described above. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a perspective view of an exemplary joint assembly according to the present application, which is shown connected to a tube end. [Figure 2] Figure 2 is a perspective view of the fitting assembly and tube end shown in Figure 1, with the individual components separated. [Figure 3] Figure 3 shows a top cross-sectional view of the joint body component of the joint assembly shown in Figure 1 in a separated state. [Figure 4] Figure 4 is a magnified view of the tube connection end portion of the joint body shown in Figure 3. [Figure 5] Figure 5 shows the joint body from Figure 3, further connected to the shell component. [Figure 6] Figure 6 is a side view of the clip component of the joint assembly shown in Figure 1 in a separated state. [Figure 7] Figure 7 is an end view of the clip component shown in Figure 6. [Figure 8] Figure 8 shows a non-limiting example of an enlarged view of the tube connection end portion of a fitting body, illustrated similarly to Figure 4, which is particularly suitable for providing freeze-resistant fittings for low-temperature applications. [Figure 9] Figure 9 shows a graph of the finite element analysis results for the joint body configuration corresponding to that shown in Figure 8. [Modes for carrying out the invention]

[0013] Embodiments of this application will now be described with reference to the drawings. In the drawings, similar reference numerals are used throughout to refer to similar elements. It will be understood that the drawings are not necessarily to exact scale.

[0014] Embodiments of this application provide an enhanced quick-connect fitting assembly that is easy to connect and effective across a wide range of environmental and operating conditions, including temperature and pressure. In exemplary embodiments, the quick-connect fitting assembly conforms to the SAE J2044 standard for liquid fuel and vapor delivery systems and associated discharge systems. Embodiments of this application employ an all-metal fitting assembly design, the metal material having a yield strength greater than 50 kpsi and suitable for operation at high temperatures (e.g., above 200°F). This all-metal design significantly improves the durability and reliability of the fitting compared to conventional configurations and is particularly suitable under conditions where the delivered fluid may freeze and expand, potentially fracturing conventional thermoplastic fitting components. Thus, embodiments of the fitting assembly of this disclosure are inherently freeze-resistant.

[0015] Figure 1 is a perspective view of an exemplary fitting assembly 10 according to this application, showing the fitting assembly 10 connected to a tube end 12. Figure 2 is a perspective view of the fitting assembly 10 and tube end 12 of Figure 1, with the individual components separated. In the exemplary embodiment, 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 tube end 12 of a fluid system component. Using the wire clip 16 as a connecting component reduces design complexity and cost and improves ease of use for the user.

[0016] In an exemplary embodiment, both the joint body 14 and the clip 16 are made of a material containing metal, and the material needs to be able to withstand a wide range of operating and environmental conditions, have a strength sufficient to withstand the operating pressure, and be non-corrosive, especially for use in fuel delivery and exhaust systems. Suitable materials include carbon-based or stainless steel materials, or brass, which meet the above physical requirements and are cost-effective. Plated steel materials, such as nickel-plated steel, may be used for specific applications, but plated steel can be relatively expensive and may not be easily used in certain corrosive environments. Since the joint body and the clip components are made of a material containing metal, the user has freedom in designing and configuring the portion of the joint body that is attached to the tube or hose. In conventional plastic materials, such freedom in design is limited due to the relatively low strength of such plastic materials. The fluid system components including the tube end 12 can be made of any suitable material as conventionally used in fluid flow systems, such as rigid plastic, steel or other metals, plastic-coated or plated steel, or other suitable materials commonly used for components of liquid systems.

[0017] As will be further detailed below, this clip-to-body attachment does not use screw connections, and therefore does not require rotation of any fitting component (body or clip) for assembly, which provides numerous advantages over conventional configurations. This clip-to-body attachment improves ease of assembly and is particularly suitable for confined spaces where it is difficult to achieve rotation of the components using typical tools. The clip 16 can be removed from the fitting body 14 with a common hand tool, such as a screwdriver or pliers that can push or "pop" the clip from the fitting body, so the configuration does not employ any dedicated removal parts added to the fitting body, as is common in conventional configurations. The clip 16 is lightweight yet effectively holds the male end of the connected tube component 12. Therefore, the fitting assembly does not require any additional retaining or interfering features incorporated into the fitting body to hold the clip in place. The ease of removal of clip 16 facilitates access to internal components of the fitting assembly, such as O-rings or other sealing parts, thereby facilitating maintenance of the fitting.

[0018] In contrast, conventional fittings typically use a stamped stainless steel piece inside the fitting body to assist in connecting and retaining the tube ends, requiring the fitting body to be specially formed for assembly and retention of the tube connection. Conventional fittings have a stamped metal J2044 connector or piece rolled into place by the fitting body, which hinders easy maintenance. Such all-metal rolled body designs cannot be disassembled with common hand tools. Many conventional configurations also use plastic spacers and plastic retainers for the O-ring. Embodiments of this application include only two retaining parts (body and clip) that accept the O-ring seal, which prevents the O-ring retaining parts from being pushed out when hard-freezing occurs due to the expansion of diesel exhaust fluid.

[0019] The joint body 14 includes a first end portion 18 and a second end portion 20 opposite to the first end portion 18. The first end portion 18 is configured to receive the tube end portion 12. As will be described in more detail below, when the tube end portion 12 is inserted into the first end portion 18 of the joint body 14, the clip 16 engages with the tube end portion 12 and the joint body 14 such that the tube end portion 12 is locked within the joint body 14, which is referred to as the connected state. In this example, the outer surface of the joint body 14 has a step, but the joint body 14 may be of any shape suitable for a particular application. In the example shown in FIGS. 1 and 2, the second end portion 20 of the joint body 14 is configured as a nipple for receiving a hose or similar component. The second end portion 20, which is a nipple, is configured to include a plurality of ribs 22. When the hose is pushed in to cover the second end portion 20, the ribs 22 assist in holding the hose to the joint assembly. In this example, the second end portion 20 is configured as a ribbed nipple for receiving a hose, but other types of fluid connections that may be suitable for any particular application may be employed as the second end portion 20.

[0020] FIG. 3 is a view showing a top cross-sectional view of the joint body component 14 of the joint assembly 10 of FIG. 1 in a separated state. FIG. 4 is a view showing an enlarged view of the tube connection end portion 24 of the joint body 14 of FIG. 3. Referring to FIGS. 1 to 4 together, the tube connection end portion 24 is positioned at the first end portion 18 of the joint body. The joint body 14 defines a fluid flow path 26 for allowing fluid to pass between the first end portion 18 and the second end portion 20. The joint body includes a main body 28 and a ring-shaped end portion 30 attached to the main body 28 via a bridge 32. The main body 28 and the ring-shaped end portion 30 define a clip slot 34 for receiving the clip 16, which can be most easily confirmed in the connected state shown in FIG. 1.

[0021] To secure the tube end 12 to the fitting assembly 10, the tube end 12 is inserted into the first end 18 of the fitting body 14 toward the second end 20. The tube end 12 may include interaction feature portions 13, such as one or more ridges or protrusions 13, that can interact with the clip 16 (see the separated view in particular of Figure 2), and the tube end is inserted sufficiently so that any interaction feature portion 13 of the tube end 12 is positioned beyond the clip slot 34 relative to the first end 18 of the fitting body 14. Once the tube end is positioned in this manner, the clip 16 is inserted into the clip slot 34. Further details of the structure and operation of the clip 16 will be described below with reference to the following drawings. Generally, the clip 16 includes opposing legs 36, 38 extending from the lateral segment 40 (see Figures 1 and 2). The legs 36 and 38 form approximately right angles (e.g., 90° ± 10°) with the lateral segment 40 at the point where each leg is joined to the lateral segment. In the connection state shown in Figure 1, the lateral segment 40 extends across the bridge 32 of the joint body 14. Since the clip legs 36 and 38 extend through the clip slot 34, the clip is maintained in a predetermined position within the clip slot between the main body 28 and the ring-shaped end 30 of the joint body 14. The legs are configured to fit tightly to the outer surface of the tube end 12 with either interaction feature portion 13 of the tube end 12 spaced further apart from the first end 18 compared to the clip 16. In this way, the interaction of the clip legs 36 and 38 with the interaction feature portion (protrusion) 13 of the tube end 12 prevents the tube end from being pulled out of the joint body 14.

[0022] To form the clip slot 34 while providing a surface for supporting the clip 16, the bridge 32 is configured as a partial part of the fitting body 14 compared to the main body 28 and the ring-shaped end 30. In other words, the bridge 32 extends only to a width very small compared to the perimeter or outer circumference of the wider fitting body component, thereby allowing the clip 16 to be inserted into the clip slot 34 in a manner that locks the tube end 12 into the fitting body as described above. Therefore, if the fitting body is made of a plastic material, as is used in many conventional configurations, the bridge 32 may constitute a weak point in the fitting assembly that is prone to breakage. Since the fitting body 14, including the bridge 32, is made of a metallic material, the bridge 32 has sufficient strength to lock the tube end without being weak or prone to breakage. Therefore, conventional thermoplastic materials may be insufficiently strong to accommodate the clip-to-body attachment of the fitting assembly 10, in that a similar thermoplastic bridge may be prone to breakage by the forces associated with locking the tube end 12 with the clip 16.

[0023] Referring particularly to Figures 3 and 4, the inner diameter 41 of the joint body 14 may include one or more sealing grooves, which can be machined into the inner diameter of the joint body. In the illustrated example, two sealing grooves 42 and 44 are provided, each capable of accommodating a sealing element, such as an O-ring seal 43 or 45 (see Figure 5). These sealing elements seal the space between the outer surface of the connected tube end 12 and the inner diameter 41 of the joint body 14 against fluid leakage. In an alternative embodiment, the inner diameter 41 may be constant, and sealing is achieved by inserting a dedicated sealing element into the joint body. Such a sealing element may be configured as a press-fit frame made of a suitable rigid material, which incorporates one or more sealing components (e.g., O-ring seals) within the frame. Thus, such a sealing element is press-fitted into the joint body such that it provides a substantial seal between the outer surface of the tube end 12 and the inner diameter 41 of the joint body 14 against fluid leakage.

[0024] Figure 5 shows the fitting body 14 of Figure 3 connected to a shell component 46. The shell component 46 is used in particular in applications where the second end 20 of the fitting body is specifically configured as a ribbed nipple for receiving a hose. The shell component 46 may be made of a metallic material equivalent to that of the fitting body 14. The fitting body 14 includes a shoulder portion 48, and the shell component 46 includes an opposing shoulder portion 50, which interact with each other to hold the shell connected to the fitting body. During assembly, the opposing shoulder portions 48 and 50 are aligned by simply sliding the shell 46 on the fitting body 14. Figure 5 shows the initial state of assembly. In this initial state, the shell component 46 flares outward radially from the opposing shoulder portions 50, thereby defining a hose receiving space 52 between the ribbed surface of the nipple end 20 of the fitting body and the inner surface of the shell 46. Furthermore, the inner surface of the shell component 46 includes a plurality of fins 54.

[0025] To connect the hose to the fitting assembly 10, the hose (not shown) is pushed in so as to cover the ribbed, nipple-shaped second end 20 of the fitting body 14. This positions the hose within the hose receiving space 52 and partially holds it in place by the ribs 22. Next, using a suitable crimping tool known in the art, the shell component 46 is crimped onto the hose, and the return 54 bites into the outer surface of the hose, thereby forming a tight connection of the hose to the fitting assembly 10.

[0026] As described above, in order to fix the tube end 12 to the joint assembly 10, the tube end 12 is inserted into the first end 18 of the joint body 14, and the tube end is locked inside the joint body 14 using the clip 16. Figure 6 is a side view of the clip component 16 of the joint assembly 10 of Figure 1 in a separated state. As also described above, the clip 16 includes opposing legs 36, 38 that extend from the lateral segment 40. Furthermore, the legs 36, 38 form approximately right angles (e.g., 90° ± 10°) with the lateral segment 40 at the position where each leg is joined to the lateral segment.

[0027] As shown in the example in Figure 6, legs 36 and 38 may each be divided into multiple segments, in the illustrated example, these segments are mirror images of each other, i.e., the segments of the first leg 36 are mirror images of the segments of the second leg 38. In one exemplary embodiment, the first segments 60a / 60b extend approximately perpendicularly from the lateral segment 40 as described above. Thus, 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 a direction away from the lateral segment 40. The second segments 62a / 62b are curved segments with a radius of curvature centered at the midpoint "+" identified in Figure 6, and are suitable for locking around a tube end 12 configured for any particular application. Therefore, 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 curves in opposite directions, and thus the second segments, when connected, collectively surround or enclose the tube end 12, thereby locking the tube end 12 within the joint body 14. The third segments 64a / 64b extend from the second segments in a direction away from the lateral segment 40, as described above, at approximately right angles to the lateral segment. Therefore, looking at 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 further essentially aligned with the first segments 60a / 60b. The fourth segment 66a / 66b extends from the third segment in a direction away from the lateral segment, and the fourth segment 66a / 66b flares outward relative to the third segment. Therefore, when the legs are viewed individually, the fourth segment 66a of the first leg 36 and the fourth segment 66b of the second leg 38 flare outward in opposite directions, moving away from each other. Any preferred angle can be used for this flare.Generally, the flare angle must be large enough to facilitate the expansion of the clip when it is pressed into place around the end of the tube for assembly. If this angle is too small, the tips of the clip legs may bite into the end of the tube and damage the male end of the tube.

[0028] Figure 7 is an end view of the clip component 16 of Figure 6. As shown in Figures 6 and 7, the flared fourth segments 66a and 66b terminate at the first clip end 70 and the second clip end 72, respectively. As shown in Figure 7, the clip legs 36 and 38 widen from the clip ends 70 and 72 toward the lateral segment 40.

[0029] Referring to Figures 1 and 2 in conjunction with Figures 6 and 7, the tube end 12 is connected to the joint assembly 10 as follows. As described above, the tube end 12 is fully inserted into the first end 18 of the joint body 14 toward the second end 20 such that the interaction feature portion (protrusion) 13 of the tube end is positioned beyond the clip slot 34 relative to the first end 18 of the joint body. Once the tube end is positioned in this manner, the clip 16 is inserted into the clip slot 34. The flared fourth segments 66a and 66b of the clip 16 assist in the insertion of the clip. The clip legs 36 and 38 act like springs, biasing them to their original positions as shown in the separated state in Figure 6. When the clip 16 is pushed into the clip slot 34 to the locked position, the pushing motion of the tube end 12 against the flared fourth segments 66a, 66b causes the clip legs 36, 38 to expand apart, thereby allowing the clip to be inserted around the tube end 12. As described above, the clip legs 36, 38 widen from the clip ends 70, 72 toward the lateral segment 40. This helps to expand the clip legs apart when the clip is inserted around the tube end 12 through the clip slot 34. The clip is inserted into the clip slot 34 until the tube end 32 comes to rest between the curved third segments 64a, 64b, and the bias of the clip 16 provides a tight hold on the tube end 12, and the interaction with the raised portion 13 of the tube end 12 locks the tube end in place. The lateral segment 40 interacting with the bridge 32 of the joint body 14 prevents further insertion of the clip 16 into the clip slot 34.

[0030] As described above, in the connection state shown in Figure 1, the lateral segment 40 of the clip 16 extends across the bridge 32 of the joint body 14. The clip 16 is maintained in place within the clip slot 34 between the main body 28 and the ring-shaped end 30 of the joint body 14, and the interaction between the interaction feature portion 13 of the tube end 12 and the clip legs 36, 38 prevents the tube end from being pulled out of the joint body 14. Furthermore, the clip legs 36, 38 are wider in the direction from the clip ends 70, 72 toward the lateral segment 40, and the lateral segment 40 is the widest part of the clip 16, so that the clip 16 is strongly held against the bridge 32 of the joint body 14, thereby eliminating breakage of the clip in the lateral segment when the clip interacts with the bridge 32 to lock the tube end in place.

[0031] The clip 16 can be removed from the fitting body 14 using a common hand tool, such as a screwdriver or pliers that can push or "pop" the clip out of the fitting body 14. In particular, the pushing motion of the tool can extend the legs 36 and 38 to separate against the biasing force of the clip, thereby allowing the legs to be pushed along the clip slot and beyond the tube end until the clip is removed. Therefore, this configuration does not employ a dedicated removal part added to the fitting body, as is common in conventional configurations. After the clip 16 is removed, the tube end 12 can be pulled out of the fitting body 14.

[0032] Figure 8 shows a non-limiting example of an enlarged view of the tube connection end portion 24 of the fitting body, illustrated similarly to Figure 4, which is particularly suitable for providing a freeze-resistant fitting configuration for low-temperature applications. It will be understood that Figure 8 shows a specific example and that variations may be adopted for specific applications. As mentioned above, in one application of quick-connect fittings, a diesel after-treatment emission system uses liquid urea (high ammonia solution) to reduce nitrous oxide. Since the freezing point of these fluids is approximately 13°F, these fluids can freeze in cold environmental conditions. When urea freezes, it expands, generating excessive force on the fluid transport hose and fitting, and the example in Figure 8 provides one configuration designed to be freeze-resistant to avoid fitting failure under such conditions.

[0033] Referring to the example in Figure 8, D1 refers to the inner diameter of the joint body 14, which again includes the main body 28 and the ring-shaped end 30 connected by the bridge 32. D2 refers to the outer diameter of the joint body 14. W1 refers to the longitudinal dimension of the ring-shaped end 30 (i.e., the dimension in the direction of fluid flow), and W2 refers to the width dimension of the ring-shaped end 30 perpendicular to W1 (i.e., the dimension perpendicular to the direction of fluid flow). Therefore, the cross-sectional area of ​​the ring-shaped end 30 is W1 × W2. W3 refers to the width dimension of the bridge 32, and S1 refers to the longitudinal dimension (in the direction of fluid flow) of the clip slot 34 defined between the main body 28 and the ring-shaped end 30. For illustrative purposes, the dimensions in Figure 8 are given in inches.

[0034] The SAE J2044 / J2045 specification requires a minimum tensile strength of 450 N or 101 lbf at 23°C (room temperature). However, field performance and laboratory testing have determined that this specification is insufficient to prevent fitting failure due to fluid freezing. Laboratory testing has determined that a fitting tensile strength of at least 500 lbf (2200 Newtons) is preferable to prevent freezing failure that occurs with more than 5% strain in glass-filled polymer plastic fittings. To design a fitting body that meets the conditions for being considered freeze-resistant, the following design elements are optimized according to the embodiments of this application: (1) Fitting material - The fitting material is selected with sufficient strength to prevent freezing failure and for chemical resistance to corrosion that may be problematic, for example, in diesel exhaust treatment systems. (2) Fitting diameter - The inner and outer diameters of the fitting body are selected with respect to appropriate sizing and engagement with the dimensions of the corresponding SAE J2044 tube stub, and are kept to a minimum to provide the maximum spacing for installation. (3) Bridge structure - The bridge (element 32 in the figure) is constructed to meet the strength requirements necessary for freeze resistance. (4) Ring-shaped end - The ring-shaped end (element 30 in the figure), which is subjected to the concentration of tensile load when freezing occurs or during tensile testing, is constructed to meet the strength requirements necessary for freeze resistance.

[0035] Regarding fitting materials, stainless steel is a suitable material choice because it is resistant to corrosion and degradation from urea solutions and has sufficient strength to prevent deformation under much higher loads than conventional glass-filled (15-30%) plastics (polyamide, PPA). Brass and plated carbon steel may not be suitable for diesel exhaust system applications due to their low corrosion resistance to urea, but they may be usable for freeze resistance in other applications where corrosion is not a concern. The properties of stainless steel materials are generally as follows: modulus of elasticity: 28,000 ksi, tensile strength: 73,000 psi, yield strength: 31,000 psi. In contrast, the properties of a typical nylon 12-30% glass-filled polymer are: modulus of elasticity: 942 ksi, tensile breaking strength: 17,400 psi, and break strain: only 5%. Such properties are generally insufficient to provide the freeze resistance mentioned above.

[0036] Regarding the inner and outer diameters of the fittings, for specific uses in accordance with the J2044 specification, the outer diameter D2 of the fitting is limited to the range of 1 / 2” (12.7 mm) to 3 / 4” (19 mm) to meet the size requirements for the dimensions of the corresponding SAE J2044 tube stub, maintain a small profile to facilitate installation, and prevent congestion when installing two or more fittings side by side. The most commonly used SAE J2044 tube stub sizes include diameters of 1 / 4” (6.3 mm), 5 / 16” (7.9 mm), and 3 / 8” (9.5 mm), and the aforementioned range of outer diameter D2 is sized to accommodate the corresponding tube stub sizes. The inner diameter of the fitting is selected in accordance with the specific SAE J2044 tube stub size used and the correspondingly specified bead diameter, as is known in the art. Generally, as is known in the art, the inner diameter D1 is equal to the bead diameter + 0.015” (0.4 mm) to 0.039” (1 mm) for sufficient clearance for mounting and insertion.

[0037] Regarding the bridge configuration, in the exemplary embodiment, the bridge width W3 is such that the outer diameter D of the joint body allows for proper spacing and alignment of the wire clips 16 to provide effective engagement with the SAE J2044 male tube stub. 2 It is within the range of 20% to 70%. Outer diameter D of the joint body 2 A bridge width W3 of less than approximately 20% of the outer diameter of the joint body D cannot provide sufficient tensile strength to be freeze-resistant. 2 A bridge width W3 greater than approximately 70% of the width cannot provide sufficient spacing for the effective installation of the wire clip 16. For example, for a fitting designed for SAE J2044 3 / 8” tube stub, the bridge width W3 would be (2.7mm)0.100” to (9.6mm)0.375”.

[0038] Regarding the ring-shaped end configuration, finite element analysis (FEA) and laboratory testing have determined that the ring-shaped end experiences the highest level of strain or deformation during freezing. Therefore, to prevent breakage or significant strain during freezing, the ring-shaped end is configured to minimize strain to 0.010” (0.25 mm) or less at a target tensile load of 500 lbf (2200 Newtons) that occurs during urea freezing. To meet this requirement, the ring-shaped end is 2.9 mm in diameter relative to a 3 / 8” SAE J2044 male stub. 2Alternatively, it is configured to have a minimum cross-sectional area (W1 × W2) of 0.0045 square inches. By minimizing the deformation of the joint to 0.010” (0.25 mm) or less, the joint can maintain the functional requirements of sealing, as well as the ability to disconnect and reassemble the joint for maintenance and / or repair of the system. More generally, when normalizing the cross-sectional area of ​​the ring-shaped end to the inner diameter D1 of the joint, the ratio of the cross-sectional area of ​​the ring-shaped end to the inner diameter D1 of the joint body must be between 21% and 73%. For example, applying such normalization to a 3 / 8” SAE J2044 male stub yields a minimum ratio of 0.212, i.e., 2.9 / 13.7. To avoid problems related to joint installation while maintaining these ratio parameters, the longitudinal dimension W1 of the ring-shaped end may be limited to approximately 0.400” or 10 mm, thereby sizing the width dimension W2 to achieve the maximum area (W1 × W2) / D1 ratio of 0.729 = 10 / 13.7.

[0039] Using FEA, the design parameters were investigated to equally determine the effectiveness of the multiple configurations described above. Figure 9 shows a graph of the FEA results, and the results are listed in the table below. Using these FEA results, the ring-shaped end maintains the highest level of strain during the application of tensile load. By repeating the FEA, 500 lbf (2200 Newtons) Under the load (0.25mm) The cross-sectional area dimensions of a ring-shaped end made of stainless steel that can withstand a displacement of 0.010” were determined. These FEA results indicate that the optimal ring cross-sectional area for achieving a freeze-resistant configuration is the same as that of the joint body. Inside 21% as a ratio to diameter D1 (mm 2 / mm) This proves that it must be at least that much.

[0040] [Table 1]

[0041] One aspect of the present invention is a metal fitting assembly, the metal fitting assembly being freeze-resistant, and employing a clip-to-body attachment for locking a tube end of a fluid system component to the fitting assembly. In an exemplary embodiment, the fitting assembly includes: a fitting body defining a fluid passage between a first end and a second end opposite to the first end, the first end being configured to receive a tube end of a first fluid system component, the fitting body defining a clip slot adjacent to the first end, the material of the fitting body being metal; and a clip, the material of the clip being metal. When inserting the tube end into the first end of the fitting body, the clip is inserted around the tube end through the clip slot, thereby engaging the tube end in a locked connection within the fitting body. The above-described joint body includes a main body and a ring-shaped end that defines the clip slot between the main body and the ring-shaped end, the joint body further includes a bridge, and the main body and the ring-shaped end are attached to each other by the bridge. For freeze resistance, the ring-shaped end is configured to minimize strain to 0.010 inches (0.25 mm) or less at a tensile load of 500 lbf (2200 Newtons). The above-described joint assembly may include one or more of the following features individually or in combination.

[0042] In one exemplary embodiment of the above joint assembly, the ratio of the cross-sectional area of ​​the ring-shaped end to the inner diameter of the joint body is 21% to 73%.

[0043] In one exemplary embodiment of the above fitting assembly, the fitting assembly is configured to connect to a 3 / 8” SAE J2044 male stub, and the ratio of the cross-sectional area of ​​the ring-shaped end to the inner diameter of the fitting body has a minimum ratio of 0.212 and a maximum ratio of 0.729.

[0044] In one exemplary embodiment of the above joint assembly, the ring-shaped end has a longitudinal dimension of 0.400” (10 mm).

[0045] In one exemplary embodiment of the above joint assembly, the bridge has a width of 20% to 70% of the outer diameter of the joint body.

[0046] In one exemplary embodiment of the joint assembly described above, the clip includes first and second opposing legs extending from a lateral segment, wherein in the connected state, the lateral segment extends across the bridge of the joint body, and the opposing legs extend through the clip slot.

[0047] In one exemplary embodiment of the joint assembly described above, the opposing first leg and second leg of the clip each comprise: a first segment extending from the lateral segment; a second segment extending from the first segment away from the lateral segment, wherein the second segment of the first leg and the second segment of the second leg curve in opposite directions around a midpoint suitable for locking around the end of the tube; a third segment extending from the second segment away from the lateral segment; and a fourth segment extending from the third segment away from the lateral segment, wherein the fourth segment of the first leg and the fourth segment of the second leg each flare out in opposite directions from the third segment of the first leg and the third segment of the second leg.

[0048] In one exemplary embodiment of the joint assembly described above, the first segment extends substantially perpendicularly from the lateral segment such that the first segment of the first leg and the first segment of the second leg are parallel, and the third segment is aligned with the first segment.

[0049] In one exemplary embodiment of the joint assembly described above, the first leg terminates at a first clip end, the second leg terminates at a second clip end, and the first and second legs widen from the first and second clip ends toward the lateral segment.

[0050] In one exemplary embodiment of the joint assembly described above, the segment of the first leg is a mirror image of the segment of the second leg.

[0051] In one exemplary embodiment of the above fitting assembly, the fitting body and / or the clip are made of stainless steel.

[0052] In one exemplary embodiment of the above joint assembly, the joint assembly conforms to the SAE J2044 standard.

[0053] In one exemplary embodiment of the above-described joint assembly, the joint assembly further includes a sealing element that provides a seal to the outer surface of the tube end in the connected state.

[0054] In one exemplary embodiment of the above joint assembly, the inner diameter of the sealing body includes a groove, and the sealing element is an O-ring seal positioned within the groove.

[0055] In one exemplary embodiment of the above joint assembly, the metal materials of the joint body and the clip have a yield strength greater than 50 kpsi.

[0056] In one exemplary embodiment of the above-described joint assembly, the second end of the joint body is configured to connect to a second component of the fluid system.

[0057] In one exemplary embodiment of the above fitting assembly, the second end of the fitting body is a ribbed nipple configured to receive a hose.

[0058] In one exemplary embodiment of the fitting assembly described above, the fitting assembly further includes a shell connected to the second end of the fitting body, the nipple and the shell defining a space for receiving the hose, and the shell being crimped around the hose to connect the hose to the fitting assembly.

[0059] While the present invention has been illustrated and described in relation to one or more specific embodiments, it will be apparent to those skilled in the art, upon reading and understanding this specification and the accompanying drawings, that equivalent alternative and modified forms can be conceived. In particular with respect to the elements described herein (parts, assemblies, devices, components, etc.), the terms used in describing these elements (including references to “means”) are intended, unless otherwise indicated, to correspond to any element that performs a specified function of the element described, even if it is an element that is not structurally equivalent to a disclosed structure that performs that function in one or more exemplary embodiments of the present invention illustrated herein. Furthermore, while certain features of the present invention have been described above with reference to only one or more of the exemplary embodiments, such features can also be combined with one or more features of other embodiments where necessary and advantageous for any or a particular application.

Claims

1. A freeze-resistant quick-connection assembly for connecting components of a fluid system, wherein the assembly comprises: A joint body defining a fluid flow path between a first end and a second end opposite to the first end, wherein the first end is configured to receive a tube end of a first fluid system component, the joint body defines a clip slot adjacent to the first end, and the material of the joint body includes metal; and A clip, wherein the material of the clip includes metal, and when inserting the tube end into the first end of the joint body, the clip is inserted around the tube end through the clip slot, thereby engaging the tube end in a locked connection state within the joint body. Equipped with, The joint body comprises a main body and a ring-shaped end that defines the clip slot between the main body and the ring-shaped end, the joint body further comprises a bridge, and the main body and the ring-shaped end are attached to each other by the bridge; The ring-shaped end is configured to minimize strain to 0.25 mm or less under a tensile load of 2200 Newtons. A freeze-resistant quick fitting assembly in which the ratio of the cross-sectional area (mm²) of the ring-shaped end to the inner diameter (mm) of the fitting body is 21% to 73% (mm² / mm).

2. The freeze-resistant quick fitting assembly according to claim 1, wherein the freeze-resistant quick fitting assembly is configured to connect to a male tube stub conforming to the 9.5 mm SAE J2044 standard, and the ratio of the cross-sectional area of ​​the ring-shaped end to the inner diameter of the fitting body has a minimum ratio of 0.212 and a maximum ratio of 0.

729.

3. The freeze-resistant quick joint assembly according to claim 2, wherein the ring-shaped end has a longitudinal dimension of 10 mm.

4. The freeze-resistant quick joint assembly according to any one of claims 1 to 3, wherein the bridge has a width of 20% to 70% of the outer diameter of the joint body.

5. The freeze-resistant quick-fit assembly according to any one of claims 1 to 4, wherein the clip includes first and second opposing legs extending from a lateral segment, and in the connected state, the lateral segment extends across the bridge of the fitting body, and the opposing legs extend through the clip slot.

6. The opposing first and second legs of the clip are, respectively: A first segment extending from the aforementioned lateral segment; A second segment extending from the first segment in a direction away from the lateral segment, wherein the second segment of the first leg and the second segment of the second leg are curved in opposite directions around a midpoint suitable for locking around the end of the tube; A third segment extending from the second segment in a direction away from the lateral segment; and A fourth segment extending from the third segment in a direction away from the lateral segment, wherein the fourth segment of the first leg and the fourth segment of the second leg flares out in the opposite direction from the third segment of the first leg and the third segment of the second leg. The freeze-resistant quick fitting assembly according to claim 5, comprising:

7. The freeze-resistant quick joint assembly according to claim 6, wherein the first segment extends substantially perpendicularly from the lateral segment such that the first segment of the first leg and the first segment of the second leg are parallel, and the third segment is aligned with the first segment.

8. The freeze-resistant quick-fit assembly according to any one of claims 5 to 7, wherein the first leg terminates at a first clip end, the second leg terminates at a second clip end, and the first leg and the second leg widen toward the lateral segment from the first clip end and the second clip end.

9. The freeze-resistant quick-connect assembly according to any one of claims 6 to 8, wherein the segment of the first leg is a mirror image of the segment of the second leg.

10. The freeze-resistant quick fitting assembly according to any one of claims 1 to 9, wherein the fitting body and / or the clip are made of stainless steel.

11. The freeze-resistant quick fitting assembly according to any one of claims 1 to 10, further comprising a sealing element for sealing the outer surface of the tube end in the connected state.

12. The freeze-resistant quick fitting assembly according to claim 11, wherein the inner diameter of the fitting body includes a groove, and the sealing element is an O-ring seal positioned within the groove.

13. The freeze-resistant quick fitting assembly according to any one of claims 1 to 12, wherein the metal material of the fitting body and the clip has a yield strength greater than 344.75 MPa.

14. The freeze-resistant quick fitting assembly according to any one of claims 1 to 13, wherein the second end of the fitting body is configured to connect to a second component of the fluid system.

15. The freeze-resistant quick fitting assembly according to claim 14, wherein the second end of the fitting body is a ribbed nipple configured to receive a hose.

16. The freeze-resistant quick fitting assembly according to claim 15, further comprising a shell connected to the second end of the fitting body, wherein the nipple and the shell define a space for receiving the hose, and the shell is crimped around the hose to connect the hose to the fitting assembly.

Images