REFLARE TOOL AND PROCESS
A flaring body has first and second opposing ends. A perimeter surface intersects the first end, and a flaring surface is located between the perimeter surface and the second end. The perimeter surface has a first cross-sectional profile with a first area, and the flaring surface having a second cross-sectional profile with a second area less than the first area. The perimeter surface and the flaring surface are joined by an inside, rounded corner. A crimping body has a top surface and an opposing bottom surface, and an interior surface that forms defines a passageway that connects said top and bottom surfaces. The interior surface has a third cross-sectional profile with a third area larger than the first area. The flaring body is slidably captureable in the passageway. The interior surface further has a crimping channel that extends along at least a portion thereof and terminates at the bottom surface.
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This application claims the benefit of U.S. Provisional Application Ser. No. 61/295,501, filed by Shailesh S. Manohar, et al., on Jan. 15, 2010, entitled “An Improved Heating Furnace for a HVAC System”, and incorporated herein by reference in its entirety. This application is related to U.S. application Ser. No. XX/XXX,XXX (attorney docket number P070075), filed by Donald N. Zimmer, et al. on ______, entitled “Heat Exchanger Expanded Overlap Joint”, commonly assigned with this application and incorporated herein by reference.
TECHNICAL FIELDThe present disclosure is directed in general to metal working, and more specifically, to metal joining.
BACKGROUNDIn some metal joining applications, a sheet metal flange is fastened to a port located in a panel or bulkhead. In some of these applications, the flange is formed of two halves, e.g. a clamshell, that have been formed separately and then joined. One flange half is typically abutted against the other flange half. If the flange is fastened to the port by flaring the flange, a gap typically forms between the flange halves. In some applications the resulting gap must be sealed to prevent leakage at the joint. The sealed gap may fail to prevent leakage when a sealant ages.
SUMMARYIn one aspect, the disclosure provides a reflare tool that includes a flaring body and a crimping body. The flaring body has a first end and a second opposing end. A perimeter surface intersects the first end, and a flaring surface is located between the perimeter surface and the second end. The perimeter surface has a first cross-sectional profile with a first area. The flaring surface has a second cross-sectional profile with a second area less than the first area. The perimeter surface and the flaring surface are joined by an inside, rounded corner. The crimping body has a top surface and an opposing bottom surface. An interior surface defines a passageway that connects the top and bottom surfaces, and has a third cross-sectional profile with a third area larger than the first area such that the flaring body is slidably captureable in the passageway. The interior surface further has a crimping channel extending along at least a portion thereof and terminating at the bottom surface.
In another aspect, a method is provided for forming a reflare tool. A flaring body is formed that has a first end and a second opposing end. A perimeter surface intersects the first end, and a flaring surface is located between the perimeter surface and the second end. The perimeter surface has a first cross-sectional profile with a first area. The flaring surface has a second cross-sectional profile with a second area less than the first area. An inside, rounded corner is formed between the perimeter surface and the flaring surface. A crimping body is formed that has a top surface and an opposing bottom surface. The crimping body includes an interior surface that defines a passageway that connects the top and bottom surfaces. The passageway has a third cross-sectional profile with a third area larger than the first area such that the flaring body is slidably captureable in the passageway. A crimping channel is formed that extends along at least a portion of the interior surface of the crimping body. The crimping channel terminates at the bottom surface of the crimping body.
In yet another aspect, a method of operating a reflare tool is provided. The method includes providing a port ring and a joint flange located within the port ring. The joint flange is flared by applying a first force to a first end of a flaring body having a second end opposing the first end. The flaring body includes a perimeter surface that intersects the first end, and a flaring surface located between the perimeter surface and the second end. The perimeter surface has a first cross-sectional profile with a first area. The flaring surface has a second cross-sectional profile with a second area less than the first area. The perimeter surface and the flaring surface are joined by an inside, rounded corner. The joint flange is crimped to the port ring by applying a second force to a top surface of a crimping body that has an opposing bottom surface. An interior surface defines a passageway connecting the top surface to the bottom surface. The interior surface has a third cross-sectional profile with a third area larger than the first area such that the flaring body is slidably captureable in the passageway. The interior surface also has a crimping channel extending along at least a portion thereof and terminating at the bottom surface.
Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Conventional fastening of crimped flange joints suffers from several significant deficiencies. Conventional crimping processes typically use several moving parts, adding complexity to the tooling and cost to the joining operation, and increasing the possibility of future failure of the joint. In some cases, such as when the crimped flange is a portion of a heat exchanger for a furnace or similar applications, exhaust gases produced by combustion of heating fuel may leak from a compromised conventional joint, creating a health or other risk to occupants of a heated building, e.g. For at least these reasons, a joint and joint crimping process is needed that reduces cost and increases reliability of the joint.
To address such deficiencies of conventional practice, the present disclosure describes novel and innovative embodiments of a flare-crimp joint between a flange and a panel port, a reflare tool to form the flare-crimp joint, and a method of forming the flare-crimp joint. Embodiments of the disclosure overcome the deficiencies of conventional practice in part by flaring and crimping the flange in a two-step operation that provides a metal-on-metal seal that remains leak-free. In some embodiments the seal flange includes overlapping flange halves that form a seam when flared and crimped by the disclosed flare and crimp tool. Such embodiments result in lower cost, greater manufacturing efficiency, and increased reliability and safety of flange seals.
Referring initially to
Turning to
Referring to
The crimping body 230 (
It is noted that while the profiles 250, 277 are circular in the illustrated embodiment, these profiles may in general be arbitrary as long as the flaring body 220 is slidably captureable within the passageway 270. For example, the passageway 270 may include a keyed portion, or the profiles 255, 277 may be elliptical.
While the port 120 and the port flange 140 are illustrated as being about circular, other shapes are within the scope of the disclosure, including oval, elliptical, square, triangular, etc. In some cases, it may be desirable to form the flare-crimp seal 170 without any gaps or breaks in the seal to ensure no leakage to or from the conduit 130. Such a seal is described in the 'XXX application (docket number P070075). In such cases, it is expected that a round or elliptical port 120 and port flange 140 will be more able than an opening with sharp corners to accommodate the stresses produced by the flare-crimp operation without compromising the seal formed by the port flange 140.
The cross-sectional profile of the flaring body 220 taken at the flaring surface 245 will typically be the same shape as the port 120 and the port flange 140. For example,
In a step 530, the crimping body 230 is formed. Again, the crimping body 230 may be formed using conventional tool materials and methods. The previously described features of the crimping body 230 are formed, including the passageway 270 in which the flaring body 220 is slideably capturable. In a step 540, the crimping channel 280 is formed. Optionally, the outside rounded corner 290 is formed.
Referring to
In a step 620, the flaring body 220 flares the port flange 140.
In a step 630, the crimping body 230 crimps the port flange 140 to the port ring 150. Referring to
Referring to
Referring back to
Turning now to
Referring initially to
Conventionally, a joint formed between a furnace heat exchanger and a panel port may present a risk of leakage of exhaust gases from the joint. Typically, two heat exchanger halves are joined such that two flange halves form butt joints where they meet. When the assembled flange is fastened to the panel port, the butt joints typically spread to form a gap. To ensure that exhaust does not leak from the joint, a sealant is typically used, adding to assembly cost and reducing reliability of the joint.
In embodiments represented by the flange 1120 and the port 1410, the overlap region 1310 forms a robust seal when the flange 1120 is joined to the port ring 1430 using a reflare tool of the disclosure, e.g. the reflare tool 210. Using an assembly method of the disclosure, e.g. the method 600, the flange 1120 is first flared by the flaring body 220, and then crimped to the port ring 1430 by the crimping body 230. The length of the overlap region 1310 may be determined to provide sufficient overlap between the flange halves 1230, 1240 in the overlap region such that no gap forms therebetween when the flange 1120 is flared and crimped. Pressure in the zone 1010 produced by the force F1 acting on the flaring surface 245 (
In some cases, it may be advantageous to limit the pressure formed at the overlap regions 1310 during the flaring and crimping operations. In such cases the flaring body 220 and the crimping body 230 may include notches at positions corresponding to the location of the overlap regions 1310. Referring to
Notably, the flare-crimp joint 1610 smoothly transitions from single-layer portions 1620, 1630 to double-layer portions (seams) 1640, 1650 that include two metal layers, e.g., the capturing tab 1320 and the terminating portion 1330. Advantageously, and in contrast to conventional practice, the flare-crimp joint 1610 does not include any sealant, and none is necessary. The flare-crimp joint 1610 forms a tight seal with the vest panel 1605, preventing leakage of exhaust gases, and obviating the need for any sealant.
Those skilled in the art to which this application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments.
Claims
1. A reflare tool comprising:
- a flaring body having a first end, a second opposing end, a perimeter surface that intersects said first end, and a flaring surface located between said perimeter surface and said second end, said perimeter surface having a first cross-sectional profile with a first area, and said flaring surface having a second cross-sectional profile with a second area less than said first area, said perimeter surface and said flaring surface being joined by an inside, rounded corner; and
- a crimping body having a top surface, an opposing bottom surface, and an interior surface that defines a passageway that connects said top and bottom surfaces and has a third cross-sectional profile with a third area larger than said first area such that said flaring body is slidably captureable in said passageway, said interior surface further having a crimping channel extending along at least a portion thereof and terminating at said bottom surface.
2. The reflare tool as recited in claim 1, wherein said second cross-sectional profile includes one or more notches.
3. The reflare tool as recited in claim 1, wherein said crimping channel has a cross-sectional profile that is about circular.
4. The reflare tool as recited in claim 1, further comprising a source of a force applied to said first end that is able to apply a first force to said flaring body during said flaring and a different second force to said flaring body during said crimping.
5. The reflare tool as recited in claim 1, wherein said crimping channel includes a sloped channel sidewall.
6. The reflare tool as recited in claim 1, wherein said crimping body and said flaring body are formed from hardened tool steel.
7. The reflare tool as recited in claim 1, wherein said passageway includes a keyed portion.
8. A method of forming a reflare tool, comprising:
- forming a flaring body having a first end, a second opposing end, a perimeter surface that intersects said first end, and a flaring surface located between said perimeter surface and said second end, said perimeter surface having a first cross-sectional profile with a first area, and said flaring surface having a second cross-sectional profile with a second area less than said first area;
- forming an inside, rounded corner between said perimeter surface and said flaring surface;
- forming a crimping body having a top surface, an opposing bottom surface, and an interior surface that defines a passageway that connects said top and bottom surfaces and has a third cross-sectional profile with a third area larger than said first area such that said flaring body is slidably captureable in said passageway; and
- forming a crimping channel extending along at least a portion of said interior surface of said crimping body, and terminating at said bottom surface of said crimping body.
9. The method as recited in claim 8, wherein said second cross-sectional profile is about circular.
10. The method as recited in claim 8, wherein said crimping channel has a cross-sectional profile that is about circular.
11. The method as recited in claim 8, further comprising coupling to said flaring body a source of a first force, and coupling to said crimping body a source of a second force, wherein said first force can be applied independently of said first force.
12. The method as recited in claim 8, wherein said passageway includes a keyed portion.
13. The method as recited in claim 8, further comprising forming said crimping body and said flaring body from tool steel.
14. The method as recited in claim 8, further comprising forming said crimping channel with a sloped sidewall.
15. A method of operating a reflare tool, comprising:
- providing a port ring and a joint flange located within said port ring;
- flaring said joint flange by applying a first force to a first end of a flaring body having a second end opposing said first end, a perimeter surface that intersects said first end, and a flaring surface located between said perimeter surface and said second end, said perimeter surface having a first cross-sectional profile with a first area, and said flaring surface having a second cross-sectional profile with a second area less than said first area, said perimeter surface and said flaring surface being joined by an inside, rounded corner; and
- crimping said joint flange to said port ring by applying a second force to a top surface of a crimping body having an interior surface that defines a passageway connecting said top surface to an opposing bottom surface, said interior surface having a third cross-sectional profile with a third area larger than said first area such that said flaring body is slidably captureable in said passageway, said interior surface further having a crimping channel extending along at least a portion thereof and terminating at said bottom surface.
16. The method as recited in claim 15, further comprising compressing said joint flange and said port ring between said flaring surface and a channel sidewall of said crimping channel.
17. The method as recited in claim 15, wherein said second cross-sectional area is about circular.
18. The method as recited in claim 15, further comprising applying a first value of said first force to said flaring body during said flaring and a different second value of said first force to said flaring body during said crimping.
19. The method as recited in claim 15, wherein a flare-crimp joint formed by said flaring and crimping is sealant-free.
20. The method as recited in claim 15, wherein said joint flange is a portion of a furnace heat exchanger.
Type: Application
Filed: Jul 12, 2010
Publication Date: Jul 21, 2011
Applicant: Lennox Industries Inc. (Richardson, TX)
Inventors: Donald N. Zimmer (Marshalltown, IA), Randy D. Smith (Marshalltown, IA), Roger W. Vreeland (Marshalltown, IA)
Application Number: 12/834,660
International Classification: B21D 31/00 (20060101); B21K 5/20 (20060101);