The present disclosure is related to railcars, and more particularly to a system and method for manufacturing railcar yokes.
Railcar yokes are generally manufactured through a casting process with steel or other alloy. Conventional methods of manufacturing railcar yokes have included producing yoke castings in cavities formed across cope and drag mold portions of a casting box. The perimeter boundaries of each of these cavities are split between the cope and drag mold portions. As such, a traditional casting box cannot produce a yoke casting entirely in the cope mold portion and another yoke casting entirely in the drag mold portion.
The teachings of the present disclosure relate to a system and method for manufacturing railcar yokes. In accordance with one embodiment, a method for manufacturing railcar yokes includes providing a cope mold portion having internal walls defining at least in part perimeter boundaries of at least two upper yoke mold cavities. The method further comprises providing a drag mold portion having internal walls defining at least in part perimeter boundaries of at least two lower yoke mold cavities. A slab core is positioned within the drag mold portion. The slab core is configured to define at least in part perimeter boundaries of the at least two upper yoke mold cavities and the at least two lower yoke mold cavities. The cope and drag mold portions are closed with the slab core therebetween. The method also comprises at least partially filling the at least two upper and at least two lower yoke mold cavities with a molten alloy to form a first, second, third, and fourth yokes.
Technical advantages of particular embodiments may include using a slab core in a casting box to enable the production of separate and unique stackable cores, thereby optimizing the production.
Another technical advantage of particular embodiments includes vertically stacking yoke cavities within a casting box by positioning a slab core between the cope and drag mold portions. Accordingly, at least four yokes may be produced within the casting box at a time, which in turn reduces manufacturing costs and the amount of time and labor required to cast railcar yokes. Thus, the production of railcar yokes may be optimized.
Yet another technical advantage of particular embodiments includes vent slots in the cope and drag mold portions, which facilitate solidification of the molten alloy by allowing gases to escape from the casting box.
A further technical advantage of particular embodiments may include positioning chills within the head portions of the drag and cope molds to provide desired directional solidification of the molten alloy in the yoke cavities.
Other technical advantages will be readily apparent to one of ordinary skill in the art from the following figures, descriptions, and claims included herein. Moreover, while specific advantages have been enumerated above, certain embodiments of the invention may include all, some, or none of the enumerated advantages.
A more complete understanding of embodiments of the disclosure will be apparent from the detailed description taken in conjunction with the accompanying drawings in which:
Example embodiments and their advantages are best understood by referring to
Railcar yokes are generally manufactured through a casting process with steel or other alloy. Conventional methods of manufacturing railcar yokes have included producing yoke castings in cavities formed across cope and drag mold portions of a casting box. The perimeter boundaries of each of these cavities are split between the cope and drag mold portions. As such, a traditional casting box cannot produce a yoke casting entirely in the cope mold portion and another yoke casting entirely in the drag mold portion. The teachings of this disclosure recognize that it would be desirable to incorporate a non-metallic separator (e.g., a slab core) into a system and method for manufacturing railcar yokes to enable the production of separate and unique stackable cores, and to optimize the production of railcar yokes by creating yoke castings in the cope mold portions and other yoke castings in the drag mold portions, thereby doubling the production of railcar yokes within a casting box.
In general, manufacturing assembly 100 includes one or more non-metallic separators, such as one or more slab cores 106, that may be used to form multiple cavities within manufacturing assembly 100. Example slab cores 106 may comprise ceramic, fiber, graphite, plaster, sand, resin, any other refractory material, any other suitable material, and/or any combination of the preceding. In certain embodiments, slab cores 106 may be configured to define at least in part perimeter boundaries of at least four cavities. Additionally, the use of slab cores 106 may enable the production of separate and unique stackable cores within manufacturing assembly 100.
Slab cores 106 are typically positioned between drag mold 102 and cope mold 104 to separate the upper half of the casting box from the lower half of the casting box. This may allow yoke mold cavities to be vertically stacked within the casting box such that at least two yoke castings may be produced in the cope mold portion and at least two other yoke castings may be produced in the drag mold portion.
In an example embodiment, once slab cores 106 are in place, drag mold 102 and cope mold 104 may be brought together and closed along their parting line. As a result, two lower yoke cavities may be created between drag mold 102 and slab cores 106 and two upper yoke cavities may be created between cope mold 104 and slab cores 106. In other words, slab cores 106 separate drag mold 102 from cope mold 104 such that at least two yokes may be cast in drag mold 102 and at least two other yokes may be cast in cope mold 104. In certain embodiments, each cavity created in manufacturing assembly 100 may include a head portion for forming the head end section of a yoke casting, a strap portion for forming the strap sections of the yoke casting, and a butt portion for forming the butt end section of the yoke casting.
Manufacturing assembly 100 may also include a gating assembly 108, head cores 110, chills 112, and vents 114. Gating assembly 108 generally fits within drag mold 102 and receives the molten alloy for the yoke castings. In certain embodiments, gating assembly 108 may include ingates through which a liquid metal or alloy may enter the cavities. In the illustrated embodiment, manufacturing assembly 100 utilizes a top gating system that allows the molten alloy to enter at the top of manufacturing assembly 100 to promote directional solidification from the lower castings to the upper castings (e.g., the lower cavities are filled before the upper cavities are filled). Other embodiments may use other types of gating systems.
Head cores 110 are generally used to form head cavities in the yoke castings when the molten alloy solidifies around the cores. A head core 110 may comprise sand resin and/or any other suitable material. In certain embodiments, each head core 110 may form a portion of a boundary for a draft gear pocket of a yoke casting (which allows a yoke to receive a draft gear assembly that connects couplers of adjoining railcars).
Chills 112 may be utilized by manufacturing assembly 100 to provide desired directional solidification of the molten alloy in the cavities. In particular, chills 112 may facilitate solidification of the molten alloy by absorbing heat in certain portions of the cavities. Similarly, vents 114 also facilitate solidification of the molten alloy by allowing gases to escape from manufacturing assembly 100. Thus, chills 112 and vents 114 may be used to reduce the risk of undesirable holes or other voids being formed in the yoke castings.
Although
Furthermore, although drag mold 102, cope mold 104, slab cores 106, gating assembly 108, and head cores 110 are illustrated as being separate components from each other, in certain embodiments, drag mold 102, cope mold 104, slab cores 106, gating assembly 108, and/or head cores 110 may be integrated with any components of
As illustrated, drag mold 102 includes internal walls, formed of sand, that define at least in part perimeter boundaries of at least two yoke cavities, such as lower cavities 116, into which the molten alloy is poured and solidifies for manufacturing at least two yoke castings. Lower cavities 116 may be formed using a pattern and a high-pressure process. Each lower cavity 116 generally defines at least a portion of the exterior surfaces of a yoke casting. For example, a lower cavity 116 may correspond to the desired shape and configuration of a yoke to be cast in drag mold 102. In certain embodiments, each lower cavity 116 may include a head portion 120, a strap portion 122, and a butt portion 124. Although
Drag mold 102 may also include vents 114 to facilitate solidification of the molten alloy that is poured into lower cavities 116 for casting the at least two yokes. Vents 114 may be configured to allow gases produced during the manufacturing process to escape from the inside of manufacturing assembly 100. As such, gases may pass freely through vents 114 so that the gases may be transferred from inside to outside of manufacturing assembly 100, which may prevent holes from forming in the metal as it solidifies. In certain embodiments, vents 114 may refer to slots in drag mold 102. Although
In general, cope mold 104 includes internal walls, formed of sand, that define at least in part perimeter boundaries of at least two yoke cavities, such as upper cavities 118, into which the molten alloy is poured and solidifies for manufacturing at least two other yoke castings. Upper cavities 118 may be formed using a pattern and a high-pressure process. Each upper cavity 118 generally defines at least a portion of the exterior surfaces of a yoke casting. For example, an upper cavity 118 may correspond to the desired shape and configuration of a yoke to be cast in cope mold 104. In certain embodiments, each upper cavity 118 may include a head portion 120, a strap portion 122, and a butt portion 124. Although
Cope mold 104 may also include vents 114 to facilitate solidification of the molten alloy that is poured into upper cavities 118 for casting the at least two other yokes. Vents 114 may be configured to allow gases produced during the manufacturing process to escape the casting box, which may prevent holes from forming in the metal as it solidifies. As such, these gases are allowed to flow through vents 114 to the outside of manufacturing assembly 100. In certain embodiments, vents 114 may refer to slots in cope mold 104. Although
Slab core 106 is generally configured to separate cope and drag mold portions (e.g., separate cope mold 104 from drag mold 102), such that upper cavities 118 are isolated from lower cavities 116. By doing so, at least two yoke castings 130, such as yoke castings 130a and 130b, may be formed in portions of drag mold 102 while at least two other yoke castings 130, such as yoke castings 130c and 130d, may be formed in portions of cope mold 104.
Thus, the use of slab core 106 generally facilitates the production of separate and unique stackable cores. For example, a slab core 106 may allow for the vertical stacking of cavities within a manufacturing assembly 100. In such an example, upper cavities 118 may be stacked on top of lower cavities 116 with slab core 106 therebetween. Technical advantages of this embodiment include casting multiple yokes at a time using only one manufacturing assembly 100, which thereby reduces the cost and amount of time and labor required to cast railcar yokes.
In certain embodiments, the lower yoke castings (e.g., yoke castings 130a and 130b) may be positioned in a first direction, while the upper yoke castings (e.g., yoke castings 130c and 130d) may be positioned in a second direction. The second direction may be a direction opposite from the first direction.
According to the illustrated embodiment, positioning slab core 106 between drag and cope molds 102 and 104 may result in two or more parting lines. For example, a parting line 135 may be formed between drag mold 102 and the bottom of slab core 106, and a parting line 140 may be formed between cope mold 104 and the top of slab core 106. In certain embodiments, parting line 135 and/or parting line 140 may be offset.
In certain embodiments, the bottom side of slab core 106 may define at least in part perimeter boundaries of at least two lower yoke cavities, such as lower cavities 116. Additionally, the top side of slab core 106 may be configured to define at least in part perimeter boundaries of at least two upper yoke cavities, such as upper cavities 118. In certain embodiments, slab core 106 may include head portions, strap portions, and butt portions for each of the respective cavities, such as head portions 120, strap portions 122, and butt portions 124 of
In an example embodiment, at least two head cores 110 may first be placed in an appropriate location within drag mold 102. For example, a head core 110a may be positioned within a portion of drag mold 102 and another head core 110 (e.g., a head core located under slab core 106b) may be positioned within another portion of drag mold 102.
Slab cores 106 may then be positioned within drag mold 102 to form lower cavities 116. For example, slab cores 106a and 106d may be positioned within drag mold 102 to form lower cavity 116a, while slab cores 106b and 106c may be positioned within drag mold 102 to form lower cavity 116b. In such an example, slab core 106a and slab core 106b may be aligned with and/or coupled to head core 110a and another head core 110, respectively.
After slab cores 106 are placed within drag mold 102, at least two other head cores 110 may be positioned within drag mold 102 and/or coupled to slab cores 106. For example, head cores 110c and 110d may be coupled to the top of slab cores 106c and 106d, respectively.
Next, gating assembly 108 may be positioned within drag mold 102. In certain embodiments, gating assembly 108 may be inserted between slab cores 106a and 106d and slab cores 106b and 106c. Once slab cores 106, gating assembly 108, and head cores 110 have been placed within drag mold 102, cope mold 104 may be aligned with and coupled to drag mold 102 to close manufacturing assembly 100 and form upper cavities 118.
Although
In certain embodiments, gating assembly 108 includes a sprue 145. Gating assembly 108 may receive the molten alloy for the yoke castings via sprue 145. In certain embodiments, gating assembly 108 may include ingates through which the molten alloy may enter the cavities. In certain embodiments, gating assembly 108 may be coupled to one or more riser sleeves. A riser sleeve may insulate a riser portion that is formed from solidification of the liquid alloy after it flows down through lower cavities 116 and upper cavities 118.
Although particular examples of a gating assembly 108 have been described, this disclosure contemplates any suitable gating assembly 108 comprising any suitable components, according to particular needs. Also, gating assembly 108 may be separate from or integral to any component of manufacturing assembly 100.
When manufacturing the yoke castings, the molten alloy flows down through sprue 145 and enters lower cavities 116 and upper cavities 118 after flowing through ingates of gating assembly 108. The alloy flows out to lower cavities 116 and then back up into upper cavities 118. In certain embodiments, after flowing into upper cavities 118, the alloy may flow back up through one or more riser sleeves.
Although
In the illustrated embodiment, chills 112 are positioned within drag mold 102 and/or cope mold 104 in a butterfly placement. The present disclosure contemplates that chills 112 may be positioned anywhere and in any placement within drag mold 102 and/or cope mold 104. In certain embodiments, chills 112 may be permanent in drag mold 102 and/or cope mold 104 and thus reusable for casting multiple yokes in the same molds.
In certain embodiments, chills 112 may assist in providing a desired directional solidification by helping to ensure that the liquid alloy solidifies from the outside of the cavities towards the inside. In certain embodiments, chills 112 may cause the molten alloy to solidify first in the head portion of the cavities (e.g., a head portion 120 of a lower cavity 116 and/or an upper cavity 118 of
Although
In certain embodiments, a reservoir, such as a riser sleeve, may be attached to a gating assembly 208 to prevent voids from forming in yoke castings 200 as the metal alloy shrinks upon cooling. Thus, in embodiments where manufacturing assembly 100 includes one or more riser sleeves, one or more riser portions 210 (e.g., riser portions 210a, 210b, and 210c) may be formed from solidification of the liquid alloy after it flows down through lower cavities 116, then upper cavities 118, and back up through the riser sleeves. In certain embodiments, these riser portions may be coupled to yoke castings 200.
In certain embodiments, the riser sleeves may allow for more even distribution of the molten alloy during solidification and may increase the likelihood of avoiding casting irregularities, for example, by reducing porosity in sections of the cavities. In such embodiments, riser portions 210 that remain after removing yoke castings 200 from manufacturing assembly 100 may be machined away. For example, riser portions 210 may be removed by being struck with a hammer or other instrument.
The method begins at step 302 where a cope mold portion, such as cope mold 104, is provided. Cope mold 104 may include internal walls that define at least in part perimeter boundaries of at least two upper yoke mold cavities, such as part of upper cavities 118. In certain embodiments, cope mold 104 may also include vent slots, such as vents 114.
A drag mold portion, such as drag mold 102, may be provided at step 304. Drag mold 102 may include internal walls that define at least in part perimeter boundaries of at least two lower yoke mold cavities, such as part of lower cavities 116. In certain embodiments, drag mold 102 may also include vent slots, such as vents 114.
At step 306, a slab core, such as a slab core 106, is positioned within drag mold 102. Slab core 106 is generally configured to define at least in part perimeter boundaries of two upper yoke mold cavities, such as part of upper cavities 118, and at least in part perimeter boundaries of two lower yoke mold cavities, such as lower cavities 116. Slab core 106 may also be configured to separate drag mold 102 and cope mold 104 such that lower cavities 116 are separated from upper cavities 118. As such, at least two yoke castings 200 may be produced between drag mold 102 and slab core 106 and at least two other yoke castings 200 may be produced between cope mold 104 and slab core 106. In certain embodiments, positioning slab core 106 within drag mold 102 creates lower cavities 116. These cavities may correspond to the desired shape and configuration of two yokes to be cast between drag mold 102 and slab core 106.
In certain embodiments, one or more internal cores may be inserted in lower cavities 116 or coupled to each other and/or drag mold 102 to form various openings or cavities of one or more yoke castings 200. For example, before slab core 106 is positioned within drag mold 102, two head cores 110 may be placed at an appropriate location within drag mold 102. In particular, each head core 110 may be positioned within a respective head portion 120 of drag mold 102. Each head core 110 is generally configured to form a head cavity within a yoke casting 200.
At step 308, cope mold 104 and drag mold 102 may be closed with slab core 106 (and head cores 110) therebetween. The closing of cope mold 104 and drag mold 102 may create upper cavities 118. These cavities may correspond to the desired shape and configuration of two yokes to be cast between cope mold 104 and slab core 106.
In certain embodiments, one or more internal cores may be inserted in upper cavities 118 or coupled to each other, cope mold 102 and/or slab core 106 to form various openings or cavities of one or more yoke castings 200. For example, before closing cope mold 104 and drag mold 102, two other head cores 110 may be placed at an appropriate location within drag mold 102 and/or on top of slab core 106. In particular, each other head core 110 may be positioned within a respective head portion 120 of slab core 106. Each head core 110 may be configured to form a head cavity within a yoke casting 200.
In certain embodiments, a gating assembly, such as gating assembly 108, may be positioned within drag mold 102 before cope mold 104 and drag mold 102 are closed. Gating assembly 108 may be configured to allow the molten alloy to first enter lower cavities 116 and then enter upper cavities 118.
At step 310, lower cavities 116 and upper cavities 118 are at least partially filled, using any suitable machinery, with a molten alloy which solidifies to form the yoke castings, such as yoke castings 200. In certain embodiments, lower cavities 116 are filled with the molten alloy prior to the molten alloy flowing into upper cavities 118. For example, the molten alloy may enter and fill lower cavities 116 before entering and filling upper cavities 118. After these cavities are filled with a molten alloy, the alloy eventually cools and solidifies into yoke castings 200 having one or more features described above with respect to
In certain embodiments, once the yokes are cast, the cores and molds may be removed leaving yoke castings 200. Yoke castings 200 may undergo a metal finishing process that includes removing any riser portions, such as riser portions 210 of
Once the method at least partially fills lower cavities 116 and upper cavities 118, the method ends.
Some of the steps illustrated in
Teachings of the present disclosure may be satisfactorily used to manufacture railcar yokes. Modifications, additions, or omissions may be made to the systems described herein without departing from the scope of the invention. The components may be integrated or separated. As used in this document, “each” refers to each member of a set or each member of a subset of a set.
Modifications, additions, or omissions may be made to the methods described herein without departing from the scope of the invention. For example, the steps may be combined, modified, or deleted where appropriate, and additional steps may be added. Additionally, the steps may be performed in any suitable order without departing from the scope of the present disclosure.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, variations, substitutions, transformations, modifications, and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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Entry |
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PCT Notification of Transmittal of the International Search Report and the Written Opinion of the International Searching Authority, or the Declaration for International application No. PCT/US2015/062909—Mar. 8, 2016. |
Number | Date | Country | |
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20160151834 A1 | Jun 2016 | US |