Knowledge of Cutting Tools: Drill Technology _ Machining

Original Title: Knowledge of Cutting Tools: Drill Technology 1. Craft /Processing 1.1 Craft According to the diameter and total length of the designed drill bit, the alloy bar cutting machine or wire cutting equipment can be selected for fixed-length processing. For the bar cut to a fixed length, the two ends of the bar are flattened, which can be realized on a hand tool grinder. Chamfer or punch the ground end face of the alloy bar to prepare for grinding the outer diameter and shank of the drill bit, depending on whether the external grinding fixture is a male or female center. Expand the full text The excircle diameter of the drill bit, the outer diameter of the clearance part and the shank part are processed on a high-precision cylindrical grinder to ensure the design requirements of the outer diameter cylindricity, circular runout, surface finish and the like. In order to improve the machining efficiency on the CNC grinding machine, the drill point can be chamfered before the alloy bar is placed on the CNC grinding machine, for example, the drill point angle of 140 ° can be roughly ground to 142 ° during chamfering. After the chamfered alloy bar material is cleaned, the chamfered alloy bar material is transferred to a numerical control grinding machine process, and each part of the drill bit is processed on a five-axis numerical control grinding machine. If it is necessary to improve the finish of the chip groove and excircle of the drill, it can also be ground and polished with wool wheel and abrasive before or after the fifth step. Of course,mining dth bit, in this case, the drill needs to be processed in more steps. For the drill bit that has been processed to be qualified, it shall be marked by laser, and the content may be the company's brand LOGO and drill bit specifications and sizes. Package the marked drill bit, and then deliver it to a professional tool coating company for coating. Note 1. Uch as a drill chip groove. ,Borehole Drill Bits, or spiral shape or straight groove shape. This step also includes the negative chamfering of the peripheral cutting edge. Then, the cutting edge of the drill tip is processed, including the tooth clearance part of the drill tip and the relief angle part of the drill point. Then, the back part of the peripheral cutting edge is processed to grind out a certain amount of drop, so as to ensure that the contact surface between the outer diameter part and the hole wall of the workpiece is controlled in a certain proportion. 2. Machining of negative chamfering for the cutting edge of drill point ? It can be divided into CNC grinding machine processing or manual processing, which is different due to the different processes of each factory. 1.2 Processing problems When machining the excircle part of the drill bit on the cylindrical grinder, pay attention to whether the fixture fails and fully cool the alloy bar during machining, and maintain the good habit of measuring the outer diameter of the drill tip. Drill machining is carried out on the CNC grinding machine, and the programming is divided into two steps of rough and fine machining as far as possible, so as to avoid the existence of potential thermal cracks caused by too much grinding, DHD Drill bit ,overburden drilling systems, which will affect the service life of the tool. Use the material tray with reasonable design to carry out the handling of cutting tange from motorized to manual feed. 3. When drilling soft metals such as brass ? The clearance angle of the drill bit is too large, and the rake angle is not ground, so that the drill bit is automatically precessed. 4. Excessive sharpening of drill edge ? The phenomenon of chipping occurs, and the knife fails to retract quickly. Measures: 1. Shorten the cycle of changing tools . 2. Perfect installation and fixation For example, increase the support area, increase the clamping force. 3. Check the main shaft bearing and sliding groove . 4. Use high precision tool holder ,dth drill bits, such as a hydraulic tool holder. 5. Use a more ductile material . Copyright notice: Because some of the articles are from the Internet, and some of the articles are pushed without timely contact with the original author. If the above copyright issues are involved, please contact us to delete or deal with the original author. Return to Sohu to see more Responsible Editor:.
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