过去我们制造的汽油机曲轴,加工后的形状像图1所表示那样,净重约2.9公斤。它是用手工锻造的,主要工序请看图2。这种锻造方法有很多缺点:劳动量大,材料消耗大,每根曲轴的材料消耗约为锻件净重的4倍;加热次数多,锻件质量低。如果采用模锻法,由于设备的能力不足,还有一些困难。根据计算,模锻曲轴所需要的设备至少要1.5吨锻锤,而正规生产却要3吨锻锤。当时我们考虑到:锻造力量的大小和锻造工艺很有关系, In the past we made the gasoline engine crankshaft, the shape after processing as shown in Figure 1, the net weight of about 2.9 kg. It is hand forged, the main process, see Figure 2. This forging method has many shortcomings: a large amount of labor, material consumption, each crankshaft material consumption is about 4 times the net weight of the forging; heating frequency, forgings of low quality. With the die-forging method, there are still some difficulties due to insufficient capacity of the equipment. According to calculations, the equipment required for forging the crankshaft at least 1.5 tons forging hammer, while the formal production has to 3 tons forging hammer. At that time, we considered: forging strength and forging process is closely related to the size,