Nodular cast iron integral type low-floor light rail gearbox and casting method thereof

Abstract

The invention relates to a nodular cast iron integral type low-floor light rail gearbox which comprises a sprue, a cross gate, a flat ingate and a water inlet side riser, and the sprue, the cross gate, the flat ingate, the water inlet side riser and a foamed ceramic filter form a four-stage filtering structure; exothermic and insulating risers are respectively arranged at the positions, close to the flat ingate, at the lower side of a window flange surface; exothermic and insulating risers are also arranged at the positions, at the highest position of the box body, of the upper side of the window flange surface; and the water inlet side riser is arranged at the outer side of a brake clamp mounting base, an annular joint rib plate is arranged at the inner side of the brake clamp mounting base, an exothermic and insulating riser is arranged on the brake clamp mounting base, and a chilling block is arranged at the side, deviating from the water inlet side riser, of the annular joint rib plate. The casting method comprises the steps of molding and core making; assembling of a mud core; core setting and box closing; a smelting process; spheroidizing, inoculating and pouring; and heat treatment. By means of the nodular cast iron integral type low-floor light rail gearbox and the casing method, various properties, sizes, appearances, magnetic particle flaw detection and radiographic inspection of the box body all meet the technical requirement indexes.

Description

technical field [0001] The invention relates to the technical field of metal casting, in particular to a nodular cast iron integral low-floor light rail gearbox and a casting method thereof. Background technique [0002] Low-floor light rail vehicle is a new type of transportation equipment in modern cities. Its notable features are low cost, energy saving and environmental protection. The track can be directly laid on the existing road, and the vehicle stops on the ground. The distance between the vehicle and the rail surface is less than 40 cm, which is convenient for travel. It is suitable for small and medium-sized cities and areas with relatively small traffic in large cities. According to the ratio of the low floor area of ​​the vehicle to the entire vehicle floor surface, it can be divided into two types: 70% and 100%. [0003] In the prior art, 70% of the models are low-floor light rail vehicles with nodular cast iron integral gearboxes. The box body is fully suspen...

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Problems solved by technology

[0004] 1. The box body integrates various structural functions such as gear box, motor mounting seat, and brake caliper mounting seat. The structure is complex, the formability is poor, and the dimensional accuracy is difficult to guarantee;

[0005] 2. The outline size of the main body is large, the flow of the pouring system is long, defects such as cold shut, cold beans, pores, and slag inclusions are prone to occur in thin-walled areas, and structural abnormalities such as graphite floating and spheroidization recession are prone to occur in thick-walled areas;

[0006] 3. The surface magnetic particle inspection cannot meet the requirements of Class 1 specified in EN 1369:1997, and the radiographic inspection cannot meet Class A, Class B, and Class 2 of Class C determined in ASTM E186; and there are four classes D, E, F, and G defect

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