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1. In normal use, the piston rod bears alternating loads and the device rubs its surface back and forth, so high hardness and wear resistance are required at this location.
2. The product structure is relatively simple, but with a large aspect ratio, it belongs to the slender shaft category and has poor rigidity. In order to ensure machining accuracy, rough and fine turning should be separated, and both rough and fine turning should use a tool holder to reduce the deformation of the workpiece during processing. When machining the threads at both ends, a center holder should be used.
3. When selecting the positioning reference, in order to ensure the coaxiality tolerance of the components and the mutual position accuracy of each part, the machining process adopts two central hole positioning, in accordance with the principle of unified reference.
4. When grinding the outer circular surface, the workpiece is prone to deformation of the tool and elasticity, which affects the accuracy of the piston rod. Therefore, during processing, the center hole should be polished and kept clean. The tightness between it and the top should be appropriate, and good lubrication should be ensured. General selection of grinding wheel: abrasive white alumina (WA), particle size 60 #, hardness medium soft or medium to ceramic bonding agent. In addition, the width of the grinding wheel should be narrow to reduce radial grinding force. During processing, attention should be paid to the selection of grinding amount, especially the grinding depth should be small.
5. When grinding the outer circle and the 1:20 taper, the two processes need to be carried out separately. When grinding the 1:20 taper, the test piece must be ground first, and only after the test piece is qualified can the workpiece be officially ground.
6. In order to ensure the stability of the machining accuracy of the piston rod, manual straightening is not allowed throughout the entire machining process.