我厂生产135系列柴油机连杆大小端孔的精度和形位公差要求很高(大端孔径为ф102_0~(+0.021),小端孔为,中心距为280±0.015,两端孔中心线在同一平面的平行度为0.05/150,歪扭度为0.09/150)。为保证加工后连杆达到产品图纸要求,我们设计了精镗夹具(图1)。夹具体设有连杆大端孔的定位心轴3(图3),其直径为,在距外圆8毫米处铣去与推杆2的轴 I plant production 135 series diesel engine connecting rod end hole precision and shape tolerance requirements are high (large end diameter ф102_0 ~ (+0.021), the small end of the hole, the center distance of 280 ± 0.015, both ends of the hole centerline in Parallelism of the same plane is 0.05 / 150, crookedness is 0.09 / 150). In order to ensure that after processing rod to meet product drawings, we designed the fine boring fixture (Figure 1). The clamp is provided with a positioning mandrel 3 (FIG. 3) with a large end hole of the connecting rod with a diameter of 8 mm from the outer circle and milling the shaft with the push rod 2