Manufacturing process of sand core of precoated sand for coupler knuckle of locomotive coupler

Abstract

The invention relates to the technical field of locomotive coupler knuckles, in particular to a manufacturing process of a sand core of of precoated sand for a coupler knuckle of a locomotive coupler. The manufacturing process comprises the following steps of: S1, determining a hot core box process to manufacture a core, namely aiming at the characteristic of long hardening time of alkali phenolic resin self-hardening sand, using the hot core box process in a coupler knuckle core manufacturing method, and using precoated sand as a core manufacturing material; and S2, designing a hot core box specific structure, specifically, a weight reduction cavity F-shaped sand core hot core box is used for discharging two sand cores from one core box, and a coupler knuckle pin hole sand core hot core box is used for discharging four sand cores from one core box. The manufacturing process is applied to locomotive coupler knuckle production, the core manufacturing efficiency of the sand core of the coupler knuckle is improved, the manufacturing cost is reduced, and extremely considerable economic benefits are created; in addition, after the manufacturing process is adopted, the casting defects of sand inclusion, cavity penetration, core expansion, air holding and the like of the coupler knuckle are obviously reduced, a large amount of waste loss and defective product rescue cost are saved, and along with popularization of the manufacturing process, other large-batch small castings can also refer to related technologies, so that the production efficiency and quality are improved.

Description

technical field [0001] The invention relates to the technical field of a locomotive coupler knuckle, in particular to a manufacturing process of a film-coated sand core for a locomotive coupler knuckle. Background technique [0002] The coupler knuckle is an important part of the coupler. The coupler is a new type of light-duty coupler product specially used for locomotives for traction of passenger vehicles, which is upgraded from the structure of the coupler for passenger cars. as attached figure 1 As shown, the hook-wrist connection profile of the knuckle is smaller, the internal weight-reducing cavity is narrow and long "F" shape and the cross-section is spindle-shaped, and the minimum section size of the tip is only 10mm; in addition, the knuckle pin hole of 178mm×φ44mm is placed After casting, the size becomes 178mm×φ30mm. The above two changes in structure and size make it extremely difficult to clean the inner cavity of the knuckle. [0003] The difficulty of san...

AI Technical Summary

Problems solved by technology

[0004] (1) Low core-making efficiency: Since the hardening time of alkali phenolic resin self-setting sand is 20 minutes, and a large number of manual core boxes cannot be equipped, the number of sand cores that can be produced per unit production time is fixed, that is, only one hour can be produced. There are 3 sand cores for the knuckle pin hole and 3 sand cores for the weight-reducing cavity, and only 24 knuckles can be produced per day, which seriously limits the production efficiency of the knuckle

[0005] (2) Poor compactness and strength of the sand core: In the manual core production process, the sanding force, sanding time, and sanding angle of each sand core cannot be accurately controlled, and the sand core’s compactness and strength are unstable. The naked eye cannot judge whether the sand core is qualified

After the castings are poured, casting defects such as sand inclusions and cavity penetrations caused by sand core damage are often found during the cleaning process, resulting in castings being scrapped

[0006] (3) The sand mixing ratio fluctuates greatly: all raw materials such as raw sand, binder, curing agent, etc. in the core sand mixing process are manually weighed by the operator using platform scales and balances, and the cumulative error of weighing equipment and personnel As a result, the proportion of core sand in each batch is inconsistent, and the quality of sand core is difficult to stabilize

After the casting is poured, there are often casting defects such as core swelling, pores, and air suffocation, which lead to the scrapping of the casting

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