Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B31/00—Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor
  • B24B31/12—Accessories; Protective equipment or safety devices; Installations for exhaustion of dust or for sound absorption specially adapted for machines covered by group B24B31/00
  • B24B31/14—Abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B31/00—Machines or devices designed for polishing or abrading surfaces on work by means of tumbling apparatus or other apparatus in which the work and/or the abrasive material is loose; Accessories therefor
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/20—Antifreeze additives therefor, e.g. for radiator liquids

Definitions

• This invention relates to finishing of hard-surface articles such as metal, plastic, and ceramic parts, or the like. Typical of such workpieces are castings, forgings, stampings, and the like.
• finishing as used herein is used in a broad sense and is taken to mean any and all of the usual surface treatments such as polishing, grinding, descaling, bumishing, cleaning, or similar operations when implemented by vibration or tumbling.
• Such finishing methods generally involve the admixing of workpieces with solid abrasive media commonly referred to as chips" and thereafter subjecting the admixture of workpieces and chips to macroorbital motion by vibration or tumbling.
• the chips can be pebbles of natural stone, chunks of crushed rock, or shaped abrasive materials such as grains of aluminum oxide, silicon carbide,-diamond, sand, and the like, held together in a binding matrix. While various materials can be utilized as binders for the manufacture of shaped chips, one such material enjoying increasing acceptance and use in the finishing arts is ice. Chips containing abrasive grains in an ice matrix are disclosed in U.S. Pat. No. 3,324,605.
• the present invention contemplates providing finishing chips containing abrasive drains in an ice matrix, admixing workpieces to be finished with the finishing chips, imparting macroorbital motion to the resulting admixture, and circulating through the admixture a hydrocarbon-based liquid refrigerant chilled to a temperature below the melting temperature of the ice matrix.
• the finishing chips are manufactured by casting a slurry of mud-like consistency into a mold having a desired shape and which is submerged in a chilled liquid refrigerant bath. The same liquid refrigerant is then circulated from the bath through the admixture of workpieces and chips in the finishing machine.
• Chips that are employed in the finishing process can be of any desired shape depending on the finishing requirements for the particular workpieces. Suitable contours are those of a bar, nugget, cylinder, cone, cube, multi-faceted prism, tube, ring, star, and the like. Compared to the size of the abrasive grains in the chip, the chip is relatively large. Common chip sizes range from nuggets about one centimeter in diameter to prisms measuring about 5 centimeters on an edge.
• the abrasive grains can be dispersed uniformly through the ice matrix of the finishing chip, or the grains can be concentrated at surface, center, or a particular region of the chip, as desired.
• the finishing chips can be conveniently manufactured by admixing abrasive grains such as sand, aluminum oxide, silicon carbide, diamond, quartz, boron carbide, zircon, and the like, with water so as to form a slurry of mud-like consistency, casting the slurry into a mold having cavities of predetermined shape depending on the desired contour for the chip, and solidifying the cast slurry in the mold cavities by chilling to a temperature below the solidification temperature of the slurry. Upon solidification, the chips are ready for immediate use in a vibratory or tumbling finishing machine, or the chips can be stored under refrigeration for subsequent use.
• abrasive grains such as sand, aluminum oxide, silicon carbide, diamond, quartz, boron carbide, zircon, and the like
• Chilling of the slurry can be conveniently accomplished by immersing the mold into a bath of the hydrocarbon-based liquid refrigerant suitably cooled to a sufficiently low temperature. Also, the solidified chips can be dislodged from the mold while still submerged in the liquid refrigerant bath and stored there until used.
• Temperature control of the chips, and of the macroorbiting mass comprising workpieces and chips in the finishing machine, is achieved according to the present invention by circulating through the mass a suitably chilled hydrocarbon-based liquid refrigerant. It is essential that the refrigerant be circulated. Sludge buildup within the finishing chamber and caking of the individual chips is thereby minimized or prevented. Where the chips have been chilled during manufacture by immersion into a hydrocarbon-based liquid refrigerant bath, it is convenient to utilize the same refrigerant also during finishing by circulating the chilled hydrocarbon-based liquid from the bath through the admixture of chips and workpieces.
• the hydrocarbon-based liquid refrigerant can be present in the vibrating bowl in an amount up to about l5 percent by volume of the vibrating admixture and preferably in an amount of about 5 to about percent by volume of the vibrating admixture.
• the liquid refrigerant In addition to chilling the finishing chips, the liquid refrigerant also exerts an influence on the type of finish that can be produced on the workpieces and thus additionally functions as a finishing compound. For example, a more viscous refrigerant liquid will produce a finer finish; however, the cutting rate will be somewhat reduced.
• the solvent action of the liquid refrigerant aids in removing oils, cutting fluids, and similar substances that may be present on the workpieces as well as performs the function of carrying away fines generated by the abrasive action of the chips during the finishing process.
• the degreasing and/or detergent properties of the liquid refrigerant in general, will exert an influence on the type of finish that can be obtained.
• Hydrocarbon-based liquid refrigerants suitable for practicing the present invention are those which are liquids below the freezing point of water and within the temperature range of the finishing process.
• Such liquid refrigerants can be liquid hydrocarbons such as naphtha, kerosene, mineral spirits (Stoddard Solvent), and the like, and halogenated liquid hydrocarbons such as l,l,l-trichloroethane, methyl chloride, methylene chloride, carbon tetrachloride, trichloromonofluoromethane, dichlorodifluoromethane, dichloromonofluoromethane, monochlorodifluoromethane, trichlorotrifluoroethane, dichlorotetrafiuoroethane, and the like.
• the liquid hydrocarbon refrigerants particularly preferred are naphtha and mineral spirits i.e., Stoddard Solvent.
• halogenated liquid hydrocarbons particularly preferred is l, l
• the liquid refrigerant can be chilled in any convenient manner such as by cooling coils or similar heat exchange means.
• the refrigerant can be introduced into the finishing chamber such as a vibrating bowl through a spray header or similar liquid distributing means situated above the bowl and drained therefrom through a suitable drain means or near the bottom of the vibrating bowl.
• Suitable apparatus arrangement for circulation of the refrigerant liquid is shown in US Pat. No. 3,161,997.
• EXAMPLE l Sand castings of aluminum are admixed in the finishing chamber of a tub-type vibratory finishing machine with finishing chips containing finely divided silicone dioxide particles suspended in an ice matrix. A macroorbital motion is then imparted to the admixture for about 45 minutes by suitably vibrating the finishing chamber.
• EXAMPLE ll The finishing chamber of a toroidal bowl-type vibratory finishing machine is filled with finishing chips con taining finely-divided silicon dioxide particles suspended in an ice matrix. The finishing chips are then permitted to stand at ambient temperature. After about 4 to 6 hours the chips have melted and a mud cake is formed in the finishing chamber which is difficult to clean out and which clogs up the finishing chamber drain.
• a method of finishing workpieces in a finishing machine which comprises admixing said workpieces with chips containing abrasive grains in an ice matrix, imparting macroorbital motion to the resulting admixture, and circulating through the admixture a liquid refrigerant comprising a material selected from the group consisting of hydrocarbons and halogenated hydrocarbons chilled to a temperature below the melting temperature of the ice matrix.
• liquid refrigerant is mineral spirits.
• liquid refrigerant is a halogentated hydrocarbon.
• a method of finishing workpieces in a finishing machine which comprises admixing abrasive grains and water so as to form a slurry of mud-like consistency
• liquid refrigerant comprising a material selected from the group consisting of hydrocarbons and halogenated hydrocarbons chilled to a temperature below the solidification temperature of the slurry; recovering the solid chips from said bath; admixing the recovered chips with workpieces to be 6 finished; imparting macroorbital motion to the resulting admixture; and circulating the chilled liquid refrigerant from the bath through the vibrating admixture.
• the liquid refrigerant is mineral spirits.
• liquid refrigerant is a halogenated hydrocarbon.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Combustion & Propulsion (AREA)
• Thermal Sciences (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
• Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
• Auxiliary Devices For Machine Tools (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=22659156

Family Applications (1)

Country Status (7)

Cited By (5)

Citations (2)

• 1971
  • 1971-09-13 US US00180088A patent/US3745722A/en not_active Expired - Lifetime
• 1972
  • 1972-09-08 DE DE2244093A patent/DE2244093A1/de active Pending
  • 1972-09-12 GB GB4233372A patent/GB1361529A/en not_active Expired
  • 1972-09-12 FR FR7232273A patent/FR2153968A5/fr not_active Expired
  • 1972-09-12 NL NL7212377A patent/NL7212377A/xx unknown
  • 1972-09-12 IT IT29068/72A patent/IT967361B/it active
  • 1972-09-12 JP JP47091005A patent/JPS4836796A/ja active Pending

Patent Citations (2)

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