12马力发动机是我国目前小型货运车普遍采用的动力。其曲轴箱是发动机中的关键零件,采用ZL105铝合金铸造。此件形状复杂、壁厚相差悬殊,在4kgf/cm~2压力下进行水压试验,5分钟不得有渗漏现象。 曲轴箱铸件的生产,我国主要有三种工艺方式:1.压力铸造、2.低压铸造、3.重力铸造。一般砂型重力铸造很难满足使用要求,故甚少采用。压铸生产率高,精度、光洁度高,但需要锁模力为630吨以上的压铸机,一般工厂不具备这种大型设备。另外,压铸件的气孔较难克服,压铸模制造费用也高,左、右曲轴箱两套压铸模至少需6万元。而我厂自制一台低压机连同保温炉 12 horsepower engine is currently the power of small trucks in our country. Its crankcase is the key part of the engine, using ZL105 aluminum alloy casting. This complex shape, wall thickness difference between the great, under 4kgf / cm ~ 2 pressure test under pressure, no leakage for 5 minutes. Crankcase casting production, China has three main processes: 1. Pressure casting, 2. Low-pressure casting, 3. Gravity casting. Gravimetric sand casting is generally difficult to meet the requirements, so rarely used. Die casting high productivity, precision, finish, but the need for a clamping force of 630 tons or more die-casting machine, the general factory does not have such large equipment. In addition, the stomata die-casting more difficult to overcome, die-casting mold manufacturing costs are high, left and right crankcase two sets of die casting at least 60,000 yuan. And I plant a low-pressure machine with holding furnace