No machine can be made without holes. In order to connect parts, we need various sizes of screw holes, pin holes or rivet holes; in order to fix transmission parts, we need various installation holes; machine parts themselves also have many kinds of holes (such as oil holes, process holes, weight-reducing holes, etc.). [1] The operation of processing holes to meet the requirements is called hole processing.
Characteristics of Hole Processing Tools - Deep Hole Processing Manufacturers:
(1) Most of the hole-processing tools are fixed-size tools, and the dimensional and shape accuracy of the tool itself inevitably has an important impact on the hole-processing accuracy.
(2) Because of the limitation of the diameter of the hole, the cross-sectional dimension of the tool is smaller, which is characterized by the smaller cross-sectional dimension of the tool used to process small diameter holes and larger depth-to-diameter ratio (the ratio of depth to diameter) holes, so that the tool has poor rigidity, unstable cutting and is prone to vibration.
(3) Hole cutting tools are machined around the machined surface of the workpiece. Cutting is in a closed or semi-closed state, so it is difficult to remove chips, cutting fluid is not easy to enter the cutting area, and it is difficult to observe the actual situation in cutting, which will have a negative impact on the quality of the workpiece and tool life.
(4) There are many kinds and specifications of hole processing tools.
Processing methods for deep and slender holes:
Central hole - Drilling - reaming - reaming is mainly processed by special equipment and special auxiliary tooling. Deep hole processing refers to the ratio of hole depth to diameter L/d (> 5 holes). Modern deep hole processing. Its characteristics are high efficiency, good quality and low labor intensity. But for some small and medium-sized processing enterprises and individual processing households generally do not have the above equipment. Because it is poor and simple, it can only be adapted to local conditions. On ordinary machine tools, deep and slender holes are processed with simple tooling. As shown in Fig. 1, a dimension of thin holes with a cylindricity of 115 mm is machined. When drilling directly or with a bit, the heat generated by one-time cutting is large, and there is not enough time to eliminate the processing errors caused by thermal deformation and residual stress on the surface of the hole wall after drilling. It is not suitable for finishing reaming directly. Therefore, the roughness of the hole wall is larger. In order to reduce the influence of thermal deformation and residual stress on finishing and improve the accuracy of subsequent processing. Processing procedures are as follows: multiple hole enlargement and full pouring of coolant should be adopted to reduce the processing errors left by rough processing.
