Method for casting ledges of middle troughs of scraper conveyer by V (vacuum) method

Abstract

The invention discloses a method for casting ledges of middle troughs of a scraper conveyer by the V (vacuum) method. A sand box adopts a vacuum sand box consisting of an upper sand box and a lower sand box which are combined with each other as well as independently-controlled vacuum chambers; a sucker with densely-arranged air suction holes is arranged on a concave-convex part of each model; a covering film on each model is required to be compacted; the surface of an EV film is coated with a zircon power fireproof coating which is 0.9-1.1 mm in thickness; the ramming time is 5-20 seconds; air exhaust holes are also formed at dry sand and pouring gates; the vacuum degree is always kept at 0.04-0.06 MPa in processes of rapping, assembling and pouring; the pouring is implemented by an inclined pouring manner within 60-70 seconds; after the pouring is finished, the vacuum degree is adjusted to be 0.02 MPa and is kept for 10-15 minutes; then negative pressure can be withdrawn to wait for falling of sand for box removal. By the technical measures, the ledges of the middle troughs with high quality and high yield can be cast by the V method.

Description

technical field [0001] The invention relates to a casting method, in particular to a method for casting a groove in the middle of a scraper conveyor using a V method. Background technique [0002] V-method casting is also known as negative pressure casting, which is named after the prefix "V" of the English word Vacuum (vacuum). Its biggest advantage over traditional sand casting is that it does not use adhesives. V-method casting uses a plastic film to seal the sand box, the air in the mold is drawn out by a vacuum pumping system, and the pressure difference between the inside and outside of the mold makes the dry sand dense to form the required cavity. After setting the core, closing the box, vacuuming, pouring, solidifying, and then releasing the negative pressure, the molding sand collapses and the casting is obtained. [0003] The process of V method molding is: [0004] 1. Place the pattern: put the pattern on the template, which has a large number of ventilation ho...

AI Technical Summary

Problems solved by technology

However, because the structure of the middle groove is too complicated, and the thickness varies from place to place, casting the middle groove with the ordinary V method has disadvantages such as large deformation and inability to cast.

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