Generally, drills with a diameter of more than 1 mm are called small hole drills, and drills with a diameter of less than 1 mm are called micro-hole drills. The processing of micro-holes is very difficult, which is a recognized processing problem at home and abroad. According to the processing principle, the processing methods of micro-hole drilling can be divided into two categories: mechanical processing and special processing. According to statistics, according to the basic conditions such as different micro-holes to be processed, precision, surface roughness, size and shape, there are about 50 types. A method of machining microholes, such as chemical, laser, twist drill, plasma beam and abrasive.
1. Għodda għażla ħiliet
(1) The geometric shape of the micro drill is mostly a stepped drill, li can effectively increase the rigidity of the tool, prevent the cutting part from swinging, and facilitate manufacturing and clamping.
(2) The precision requirements of the tool holder and chuck are high, għax any radial runout error will have a great impact on the micro drill.
(3) The matrix material of the micro-drill is mostly cobalt-containing powder high-speed steel and cemented carbide, and some have a composite structure, such as adding diamond and cubic boron oxide to the front of the drill, and coating the outside of the the tool with TiC and PCD coatings.
(4) The general drilling depth of micro-drills is 10 to 15 times the diameter, and the roundness error of the aperture can be controlled within 0.0025mm.
2. Kif biex tuża l-għodda l-għodda
(1) Matul mikro-toqba tħaffir, peress li ċ-ċipep iffurmati huma żgħar jew even trab, il qtugħ sħana introdotta f' iċ-ċipep is mhux ħafna, u żejt mist u kkompressat arja jista' be użat biex assist in chip tneħħija u tkessiħ of the drill bit.
(2) When the micro-hole drill is drilling drilling the workpiece, the feed rate at the beginning the cut is far lower than the normal feed rate of the subsequent cut into the workpiece. For example, when processing titanium alloys and high-temperature alloys, the initial feed rate is 0.0}02mm. The normal feed rate is 0.005mm.
(3) Meta mikro-tħaffir partijiet, it it is best to cut into the workpiece at a vertical angle.
(4) The feed axis of the machine tool must have sufficient sensitivity and small enough resolution. The spindle has high precision, good rigidity, good stability, and low vibration. Dynamic balance testing must be done before processing.
5) Meta tħaffir ma mikro-drills, the "pecking" tħaffir metodu is ġeneralment użat.
6) Il mikro-drill must be selected to match the material to be processed, the geometry of the drill tip should be selected according the material to be processed, and reasonable cutting parameters should be formulated in order to give full play to the massimu l-massimu ipproċessar effiċjenza tal-mikro-drill.
