挤压铸造液压阀体

Squeeze Casting for Valve Bodies

针对煤矿支护用45钢阀体(也叫双向柱头)消耗量大、规格单一、质量可靠性要求高的特点,采用挤压铸造技术进行生产,既可以满足使用要求又可以节约材料。其主要工艺方案是:垂直浇注、一模一件、双向对挤、侧压抽芯。试生产证明,使用专用涂料和带有冷却水系统的压头可以显著提高模具寿命;获得致密产品的主要工艺参数:浇注温度1510～1530℃,模具预热温度150～260℃,开始加压时间小于10s,比压150～200 MPa,持压时间8～12s。生产统计表明,其生产效率可达800件/天,工艺出品率高达85%左右,与圆钢车制相比单位成本降低20%～30%,具有良好的经济效果。

The valve body, also named reversible column heads, is an important parts widely used in hydraulic industry. Considering its large consumption, simple shapes and strict quality requirements, it is reasonable to produce valve bodies of carbon steel 45 with the squeeze casting process. The main technologies are that only one piece per mold, vertical pouring, up and down pressing and laterally pressing to form the perpendicularity and level holes respectively. It is proved that the mold＇s service life is evidently prolonged by using a special coating and a punch with cooling water systems. The main parameters obtaining sound products are. the pouring temperature 1 500-1 520 ℃, the mold preheating temperature 150-260 ℃, starting press time smaller than 10 s, specific pressure 150-200 MPa and holding for 8-12 s. It is proved that the productivity reaches 800 pieces per day and the materials yield reaches 85%, and accordingly the cost of the valve bodies is lowered by 20%-30% than that made by machining.