Design And Experimental Research In The Surface Finishing Device For Inner Hole

The research is supported by the nation science fund project (50675149) which research on "Theory and Technological Basis of. Liquid-Particle Two-Phase Compulsive Circumfluence Oriented Hole Surface Finishing". It mainly research in the inner surface finishing with grinding particles which is carried by compulsive circumfluence. Because the equipment of liquid-particle two-phase compulsive circumfluence is complicated and the closer space or circumfluence is needed, the higher locational precision between equipment and workpiece is needed. Meanwhile, the liquid has certain influence on environment, so the research improves this finishing method and proposes the grinding and finishing by means of grinding rods droved by motor which is based on centrifugal principle.Considering its difficulty to finish inner hole’s surface of deep hole, curved hole, stepped hole, etc., the difficult cleaning of inner wall for large-scale oil-pipes, and other problems, a inner hole’s surface finishing device with controllability and adaptability is put forward. The device is consist of two parts, a flexible finishing head which is designed based on the centrifugal principle and an automatic feeding device which is design based on the principle of screw gearing. By means of grinding rods, the flexible finishing head finishes surface of inner hole whose diameter is from165mm to230mm. With certain adaptive ability, automatic feeding device can reciprocate along axis of inner hole, whose diameter is ranging from234mm to254mm. Driven by automatic feeding device, the flexible finishing head finishes the surface of inner hole along axis of pipes. At the same time, under the control of commutator and speeder, the device can finish inner hole’s surface with different speed and different orientation.With theoretical analysis, the research confirms the stress state of grinding rods under different situations and calculates the minimum revolving speed for its grinding movement and its curve intensity. It also deduces, the relation revolving speed of the flexible finishing head and the grinding force between grinding rods and the inner wall of workpiece and the traction for finishing head’s feeding. Analyzing of automatic feeding device’s stress state, the study ensures the motor rate and the spring’s positive pressure which are satisfied to the traction that the flexible finishing head needed. The structural scheme of the inner hole’s surface finishing device is decided and is2-dimensional and3-dimensional modeled by means of AUTOCAD, PROE and other graphic software. The automatic feeding device and the finishing head are tested respectively. The flexible finishing head is fixed in the principle axis of bed to test finishing head’s different processing efficiency with different parameters, the influence of different particle size to finishing head’s processing performance and moving speed and traction of automatic feeding device via changing the feeding speed and revolving speed of the principle axis and analyze factors which influence the moving of automatic feeding device. The theoretical analysis and experiment of the finishing device for inner hole’s surface offer certain groundwork for further study on the finishing device.