1. Field of the Invention
The Field of Invention relates generally to flux and braze alloys, and specifically to flux coated braze alloy preforms.
2. Discussion of the Related Art
Flux is known in the art of brazing to remove oxides from the parent metal or alloy part and allow the filler metal to properly bond. Traditionally, flux has been applied to the parent part manually in the form of a paste or liquid just prior to brazing. Over time, various companies have produced filler metals that include a pre-applied flux. These filler metals with included flux eliminate the need for an operator to manually apply flux.
The manufacture of filler metals with pre-applied flux has been known as an expensive process as waste is often produced. The filler material is often dipped into a bath of flux which may result in excessive flux adhering to the filler material. This not only wastes precious flux material, but also requires extended cleaning operations following brazing as the excess flux leaves behind residue or an unsightly appearance. As the filler metal is immersed in a flux solution, it may contact other objects and the curing flux may join with the other object. Flux may also puddle or run off the part and produce overall inconsistent coatings.
Filler material is also often bent or shaped into various “preforms” such as a wire bent into a ring, helix, triangle, or any other shape. Applying flux to the preform after it is shaped extends the cycle time of production, while forming the wire into a preform following flux application often results in the flux chipping or cracking.
Additionally, many machines that apply flux to a filler metal or preform are unique to the individual part that is being treated. Oftentimes, expensive dies or machines are custom made for applying flux to a single part.
What is therefore needed is a way to apply flux to a filler metal, preform, or any object in a consistent manner. What is also needed is a way to apply the flux with minimal material handling. A way to apply a flux coating to any number of differently shaped parts with the same machine is hereby needed.
A method of applying a flux coating on a plurality of parts for a brazing operation may include tumbling the parts in a tumbling drum with a controlled atmosphere including a user-definable temperature and humidity within the tumbling drum. The parts may be cycled through a coating cycle within the drum. The cycle may include spraying a flux from at least one nozzle within the tumbling drum while the parts are tumbling for a user-defined period of time. The parts may ultimately be coated with flux with a uniform thickness within 2% to 4% of a desired thickness.
Following spraying, the parts may be tumbled for an additional user-defined period of time to cure the flux to a desired hardness. The coating cycle may then be repeated any number of times to build up a sufficient coating. The uniform thickness of the coating on the parts is thereby uniformly, incrementally increased with each coating cycle.
An alternative flux coating method for applying a flux coating on a plurality of parts for use for brazing may also include setting the parts on a conveyor that transports the parts into an enclosure with a plasma cleaning chamber to remove contaminants allowing a proper adhesion of the flux coating to the parts. The parts may then advance to a heating chamber to heat the parts with infrared light to promote better adhesion and curing of the flux. Following heating, the parts may advance to an ultrasonic flux spraying chamber where the parts may be sprayed with an ultrasonic sprayer configured to atomize a liquid flux solution and coat a single side of the parts with the flux coating, leaving an opposing side of the part free of the flux coating.
These and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
A clear conception of the advantages and features constituting the present invention and of the construction and operation of typical mechanisms provided with the present invention will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which:
In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the words “connected”, “attached”, or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments described in detail in the following description.
A process method for Flux Coating Braze preforms and Discrete parts.
A Spray Flux Coating and binder system for coating Braze preform and discrete parts.
Process Description:
The process consists of a totally enclosed rotating drum and spray mechanism using controlled heat and positive pressure to efficiently and economically flux coat a wide range of Braze preforms and cladded discrete parts.
Spray Flux Coating Description:
Spray Flux Coating formulation is designed to operate continuous and intermittent spray processes including fine micro spray systems. The coating consists of a compatible braze flux, adhesive resin, and Non VOC solvent carrier that is sprayed onto braze preforms and functional braze alloy cladded discrete components requiring braze flux. Physical functional properties of the resultant flux coating yields a controlled range of adhesive strength, durability, hardness, and flexibility to comply with designated handling requirements for packing and process loading. The operational or duty properties are constant with Flame, Induction, or Controlled atmosphere furnace requirements.
The Flux Coating Process:
Various manufacturers which produce HVAC components for automotive and commercial industries are eliminating in-house fluxing systems in favor of pre flux coated parts for improvements to overall cost, quality, output, environmental, and lean initiatives. Though some manufacturers opt to flux coat self-produced parts on site for practical reasons, there is a significant demand to outsource flux coated discrete A1 Clad parts. Improved cost, quality, and versatility may be achieved through binder technology and uniqueness of process, i.e., using the tumbling drum. The binder and process yield precision placement and loading of flux with virtually no waste or byproduct.
Beginning with
In order to control the atmosphere within the drum 17, a control panel 20 with a series of buttons and a monitor allows an operator to configure drum rotation speed and humidity within the drum 17, air temperature within the drum 17, and the amount of flux sprayed from nozzle 32, as seen in
Following completion of operation, the enclosure 12 and lid 14 may be pivoted about arm pivot 13 allowing an operator to dump the treated parts into the funnel 31 for collection into a vessel below the funnel 31.
Turning now to
After the brazing parts 34 are inserted into the drum 17, the drum sprayer is activated and the drum begins to rotate and tumble the brazing parts within. The humidity and temperature within the drum may be fine tuned to achieve the best adhesion and uniformity of atomized flux spray 30. The rotational speed of the drum may also be fine tuned to ensure optimal coating.
As the brazing parts 34 are tumbled, the sprayer 32 emits the atomized flux spray to evenly coat the brazing parts 34 with flux. The exhaust duct 24 draws out any overspray and prevents the atomized flux spray from adhering to the drum 17. The brazing parts 34 are coated with flux within 2% of the desired thickness. For example, if a 0.0050 in coating of flux is desired, the process is capable of producing a flux coating between 0.0051 in and 0.0049 in evenly and uniformly on hundreds, even thousands, of parts simultaneously.
Preferably, the sprayer does not spray the entire thickness of desired flux coating in one spray operation. Optimal results are achieved by spraying multiple coatings with a curing cycle between each spray cycle. The drum continuously rotates, agitating the brazing parts 34 during the curing cycle, and the sprayer 32 is deactivated. The temperature within the drum 17 preferably is 30-50 degrees Celsius; however, it may be adjusted for different flux coatings or different thickness of coatings. Due to the specific mixture of ingredients in the flux, the coating cures to a sufficient hardness and is durable to remain in tumbling in the drum without chipping or otherwise damaging the coating of flux. The flux formulation, including the binder, may also be adjusted for different-shaped parts. Different binders, formulations, and fluxes are shown in the following tables and examples.
As the drum 17 constantly tumbles the brazing parts 34, each part sees the same amount of spray time from the sprayer 32 and is uniformly coated. Due to the efficiency of the sprayer and the tumbling operation, 85% through 95% of the flux that is sprayed through the sprayer 32 is coated onto the brazing parts. This prevents waste and reduces manufacturing costs. Total flux coating time can vary depending on the desired thickness and the size of the parts to be coated. For example, some batches take as low as 15 minutes while others may take 25 hours. Additionally, once the drum sprayer 10 is loaded and set up, it may run unattended through multiple spray and curing cycles. This reduces labor costs and allows a single operator to run multiple machines at the same time.
Moving on to
In order to cut down even further on operator time,
An alternate embodiment of the invention may be seen in
The conveyor coater 49 allows for a part itself to be prepped for flux, and have flux applied directly to the part. This eliminates the need to apply any flux at all during assembly and manufacturing. Traditionally, flux is applied with a brush just prior to brazing. Alternatively, flux may be included inside the filler wire or coated on the filler wire. Either way, the flux must be applied at the brazing site. The conveyor coater 49 allows for batch treatment of many different parts of any size/dimension. The spray head may be located, or programmed to move, to the desired area and only spot-treat the desired areas with a flux coating. Additionally, multiple spray heads may be included to spray additional coatings. Metals or alloys may also be sprayed to eliminate the need for filler metals to be applied at the brazing site. There is no limitation on how many chambers the enclosure may include or how large the enclosure may be. Similarly, the parts do not necessarily need to be cleaned with the plasma cleaner 60 or heated with the infrared lamps 64. Any effective cleaning apparatus or heating apparatus may alternatively be used.
Looking at
Specific embodiments of the present invention will now be further described by the following, non-limiting examples which will serve to illustrate various features of significance. The examples are intended merely to facilitate an understanding of ways in which the present invention may be practiced and to further enable those of skill in the art to practice the present invention. Accordingly, the examples should not be construed as limiting the scope of the present invention.
FORMULA #8 REV 2
X6857
Alloy Code: 84-413
Description:
UT/ROTAMAT™ and spray gun compatible flux coating solution for applying a durable coating of flux loadings up to 0.015″ for hi-temp alloy braze washers. Surface enhancement is required for adhesion.
Formulation from Sub-Assembly Base:
This application claims the benefit of U.S. Application No. 61/829,109 filed May 30, 2013, the entirety of which is herein incorporated by reference.
Number | Name | Date | Kind |
---|---|---|---|
400869 | Norton et at | Apr 1880 | A |
1629748 | Stoody | May 1927 | A |
1968618 | Padgett et al. | Feb 1932 | A |
2499641 | Goody | Mar 1950 | A |
2958941 | Goerg | Nov 1960 | A |
3077131 | McShane | Feb 1963 | A |
3162551 | Short | Dec 1964 | A |
3542998 | Huff | Nov 1970 | A |
3619429 | Torigai et al. | Nov 1971 | A |
3620869 | Stump et al. | Nov 1971 | A |
3642998 | Jennings | Feb 1972 | A |
3935414 | Ballass et al. | Jan 1976 | A |
3967036 | Sadowski | Jun 1976 | A |
4041274 | Sadowski | Aug 1977 | A |
4301211 | Sloboda | Nov 1981 | A |
4379811 | Puschner et al. | Apr 1983 | A |
4447472 | Minnick et al. | May 1984 | A |
4493738 | Collier et al. | Jan 1985 | A |
4497849 | Hughes et al. | Feb 1985 | A |
4504007 | Anderson et al. | Mar 1985 | A |
4571352 | Aoki | Feb 1986 | A |
4587097 | Rabinkin et al. | May 1986 | A |
4624860 | Alber et al. | Nov 1986 | A |
4624866 | Cheng et al. | Nov 1986 | A |
4831701 | Yutaka | May 1989 | A |
5098010 | Carmichael et al. | Mar 1992 | A |
5316206 | Syslak et al. | May 1994 | A |
5368219 | Hogan et al. | Nov 1994 | A |
5418072 | Baldantoni et al. | May 1995 | A |
5450666 | Conn et al. | Sep 1995 | A |
5575933 | Ni | Nov 1996 | A |
5749971 | Ni | May 1998 | A |
5759707 | Belt et al. | Jun 1998 | A |
5781846 | Jossick | Jul 1998 | A |
5791005 | Grabowski et al. | Aug 1998 | A |
5903814 | Miura et al. | May 1999 | A |
6093761 | Schofalvi | Jul 2000 | A |
6204316 | Schofalvi | Mar 2001 | B1 |
6234381 | Hasegawa et al. | May 2001 | B1 |
6244397 | Kars | Jun 2001 | B1 |
6248860 | Sant'Angelo et al. | Jun 2001 | B1 |
6264062 | Lack et al. | Jul 2001 | B1 |
6277210 | Schuster | Aug 2001 | B1 |
6317913 | Kilmer et al. | Nov 2001 | B1 |
6344237 | Kilmer et al. | Feb 2002 | B1 |
6376585 | Schofalvi et al. | Apr 2002 | B1 |
6395223 | Schuster et al. | May 2002 | B1 |
6409074 | Katoh et al. | Jun 2002 | B1 |
6432221 | Seseke-Koyro et al. | Aug 2002 | B1 |
6497770 | Watsuji et al. | Dec 2002 | B2 |
6680359 | Schoenheider | Jan 2004 | B2 |
6713593 | Ree et al. | Mar 2004 | B2 |
6733598 | Swidersky et al. | May 2004 | B2 |
6830632 | Fuerstenau et al. | Dec 2004 | B1 |
6846862 | Schofalvi et al. | Jan 2005 | B2 |
6864346 | Schoenheider | Mar 2005 | B2 |
20020139519 | Hosoya et al. | Oct 2002 | A1 |
20030203137 | Teshima et al. | Oct 2003 | A1 |
20040009358 | Scott et al. | Jan 2004 | A1 |
20040016793 | Zhao et al. | Jan 2004 | A1 |
20040171721 | Esemplare | Sep 2004 | A1 |
20050008771 | Goto | Jan 2005 | A1 |
20050129855 | Kamata et al. | Jun 2005 | A1 |
20070093574 | Esemplare | Apr 2007 | A1 |
20070251602 | Gagnon et al. | Nov 2007 | A1 |
20100099806 | Houze et al. | Apr 2010 | A1 |
Number | Date | Country |
---|---|---|
7812546 | Nov 1977 | FR |
63303694 | Dec 1988 | JP |
WO9900444 | Jan 1999 | WO |
WO0039172 | Jul 2000 | WO |
WO0052228 | Sep 2000 | WO |
WO0064626 | Nov 2000 | WO |
WO0200569 | Jan 2002 | WO |
WO0231023 | Apr 2002 | WO |
WO03068447 | Aug 2003 | WO |
WO03089176 | Oct 2003 | WO |
WO2005061871 | Jul 2004 | WO |
WO2004094328 | Nov 2004 | WO |
Entry |
---|
“Rotamat Surface Preparation.” Mar. 16, 2010. <<http://web.archive.org/web/20100316101905/http://www.surfacepreparation.com/product/rotamat-parts-coating-system>>. |
Number | Date | Country | |
---|---|---|---|
20140374469 A1 | Dec 2014 | US |
Number | Date | Country | |
---|---|---|---|
61829109 | May 2013 | US |