Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D31/00—Cutting-off surplus material, e.g. gates; Cleaning and working on castings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
  • B23D79/00—Methods, machines, or devices not covered elsewhere, for working metal by removal of material
  • B23D79/005—Methods, machines, or devices not covered elsewhere, for working metal by removal of material for thermal deburring

Definitions

• thermal deburring also called thermochemical deburring
• the workpieces to be deburred are placed in a deburring chamber.
• Fuel gas and oxygen are introduced into the deburring chamber via metering valves.
• the gas mixture is ignited in the chamber by an electrical ignition device.
• hydrogen as the fuel gas
• the mixture burns to water, releasing heat. The process takes place within a few milliseconds. Due to the heat released, temperatures of approx. 3,000 ° C occur in the chamber.
• the deburring chamber is opened and the workpieces are replaced by new workpieces to be deburred.
• thermal deburring process results in a targeted removal of material from the workpiece to be deburred, especially on edges.
• a disadvantage here is also an unwanted, locally very differently strong removal on the surfaces forming the inner wall or; Split the deburring chamber.
• the deburring chamber according to the invention with the characterizing features of the main claim has the advantage that the tool costs for thermal deburring could be greatly reduced. Due to the separate design of the parts of the deburring chamber that are subject to different wear, smaller units can be replaced very easily and quickly. Since the deburring chambers work with considerable cycle times (e.g. 20 seconds), the deburring chamber walls are exposed to high thermal alternating loads, which can lead to cracking due to thermal shock and thus to a large reduction in the creep rupture strength. The inner walls of the deburring chamber are subjected to constant alternating stresses in rhythm with the cycle. The removal of deburring chamber parts can be up to one millimeter per 50,000 deburring cycles.
• the deburring chamber according to the invention is therefore built up in the area from easily exchangeable units which are subject to greater wear. These are in particular the inner walls of the deburring chamber.
• a particularly advantageous construction of the deburring chamber consists of a deburring chamber inner ring with an adapted deburring chamber upper part and an associated closing plate. These three matched parts limit the interior of the deburring chamber and represent the parts that are most susceptible to wear.
• the internal strength of the deburring chamber parts is designed in such a way that they can independently withstand the stresses during thermal deburring. For this purpose, a clearance fit is provided between the deburring chamber inner ring and the outer cooling ring in order to limit the constant temperature changes and thus the reduced creep resistance to the wearing part.
• This principle is also used for the top part of the deburring chamber, which has a slightly curved shape in the cold state and is form-fitting with the adapter located above when exposed to temperature.
• Another embodiment of the deburring chamber provides, however, that the inner ring is fitted into the surrounding cooling ring or an additional ring in such a way that the surrounding ring absorbs the forces and the inner ring is selected only according to wear considerations.
• FIG. 1 shows a schematic representation of a deburring chamber without an associated machine frame.
• the deburring chamber 10 is delimited by a deburring chamber inner ring 11, a deburring chamber upper part 12 and a closing plate 13 as deburring chamber walls.
• the chamber inner ring 11 is of a cooling ring 14 with cooling coils 15 surround.
• the ratio of the inner ring - wall thickness to the wall thickness of the cooling ring 14 is, for example, 2: 3. Due to the small wall thickness of the inside of the deburring chamber, a large temperature gradient in the walls is avoided. This results in a considerable reduction in the thermal stress. The durability of the parts can thus be increased significantly.
• the cooling ring 14 is made of a chrome nickel steel and is designed as a burst protection.
• the clearance fit between the inner ring 11 and the cooling ring 14 ensures that no operationally occurring loads can be transferred from the inner ring to the cooling ring.
• the cooling ring is therefore not subject to alternating stress, therefore it is not susceptible to wear and can therefore be used as a burst protection in terms of safety.
• the deburring chamber 10 is limited at the top by a deburring chamber upper part 12. Between the upper part 12 and the inner ring 11, a seal 16 is arranged such that it is not exposed to the direct temperature load.
• An adapter 17 is adapted to the deburring chamber upper part 12.
• the upper adapter 17 is designed similarly to the cooling ring 14. For this purpose, it is provided with cooling coils 18 which cool the upper part 12 of the deburring chamber.
• the deburring chamber upper part 12 is designed such that it has an inwardly curved shape when cold.
• the deburring chamber upper part 12 expands and lies in a form-fitting manner on the upper adapter 17 only when it is heated up during thermal deburring.
• the deburring chamber inner ring 11 and the deburring chamber upper part 12 are held together by means of a tie rod connection 19 between the upper adapter 17 and the cooling ring 14.
• the connection is preloaded by springs 20 to compensate for tolerances, strains and the setting process of the seal 16.
• the deburring chamber is supplied with fuel gas and oxygen through the gas connection 21.
• the lower region of the deburring chamber 10 is delimited by the closing plate 13, which connects to the inner ring 11 of the deburring chamber by means of a seal 22.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Optics & Photonics (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Crushing And Pulverization Processes (AREA)
• Furnace Housings, Linings, Walls, And Ceilings (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6707789

Family Applications (1)

Country Status (7)

Cited By (4)

Families Citing this family (8)

Citations (3)

Family Cites Families (3)

• 1979
  • 1979-09-27 DE DE19797927450U patent/DE7927450U1/de not_active Expired
• 1980
  • 1980-07-16 DE DE8080901459T patent/DE3065522D1/de not_active Expired
  • 1980-07-16 JP JP55501782A patent/JPH0122065B2/ja not_active Expired
  • 1980-07-16 US US06/253,843 patent/US4394007A/en not_active Expired - Lifetime
  • 1980-07-16 WO PCT/EP1980/000056 patent/WO1981000819A1/de active IP Right Grant
  • 1980-09-19 IT IT8022847U patent/IT8022847V0/it unknown
• 1981
  • 1981-04-08 EP EP80901459A patent/EP0036860B1/de not_active Expired
  • 1981-05-26 SU SU813288426A patent/SU1200847A3/ru active

Patent Citations (3)

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