【摘要】 钎头、钎杆早期折断和胀裤是目前钎具寿命不高的主要原因。作者在模拟凿岩机工作条件的落锤试验台上,对六种介质(钢砧、坚硬铁矿、铅、橡胶、河沙以及悬空等)测定了钎头、钎杆的轴向应力和胀裤力。对于YT—25型凿岩机,钎杆中最大轴向应力可达5300～6000公斤/厘米~2。根据测定结果,本文提出了分析意见,为钎杆和针头选材和制订热处理工艺提供了依据。更多还原

【Abstract】 The short life of drill string is mainly caused by premature fracture of steel rod and the failure of tapered shank of bit due to expansion.In this paper, the determination of the longitudinal stresses of steel rods and the expansive loads acted upon the tapered shanks of bits is described. The determination is conducted in a series of drop-hammer tests in 6 different types of media, including steel anvil,hard taconite, lead block, rubber, sand and free air, under simulated working condition of a rock drill. For YT-25 drill, the max. longitudinal stress in drill steel amounts to 5300-6000kg/cm2. By analyzing the aforementioned measurements and computations, a theoretical basis for the selection of materials and heat-treatment procedures of drill steels and drill bits is proposed.更多还原