1. Flat drill structure features: simple structure, convenient manufacturing, low cost, small axial size, good rigidity. Features of prefabricated flat drill: 1. Quick replacement of blade for in vitro regrinding, in order to save tool change time. 2. The blade material can be easily replaced to meet the requirements of different processing conditions. 3. Good rigidity of the tool bar, and the cutting fluid can be injected into the bar, which is conducive to improving the drilling efficiency and drill bit durability. The recommended geometric parameters of the flat drill are as follows: top Angle 2κr=90° ~ 140°; Front Angle γo=0° ~ 10°; Rear Angle ao=ao '=3° ~ 10°. ψ=55° ~ 60°; Width of edge belt bα1=0.2 ~ 0.5mm; The amount of inverted cone is 0.05-0.1mm to form the secondary declination Angle =2° ~ 5°. Two, reaming drill tool without cross edge, cutting conditions are better. And the number of teeth (usually 3 ~ 4), good orientation. The chip groove can be made shallow, the drill core is coarse, the strength and rigidity of the tool body is high, and the larger cutting quantity can be used when working. Countersinks are commonly used for machining countersinks, cone holes and countertops of various countersunk screws. Figure a shows flat sink drills with pilot pins for machining cylindrical countersinks. Figure b shows a 90° cone countersink with pilot posts for machining taper countersinks. For cone countersinks without pilot posts, there are three types of taper angles of 60°, 90° and 120° for machining center holes or hole mouth chamfering. Countersinks can be manufactured into high-speed steel countersinks, carbide countersinks and indexable countersinks. Twist drills are often converted into countersinks for use in small batch production of single pieces. 1. Through hole turning tool
5. Deep hole rolling tool Deep hole rolling machining is a kind of rolling extrusion machining method on the inner surface of deep hole with rolling tool on horizontal lathe. It is a high efficiency finishing method to improve the surface hardness of parts and reduce the surface roughness value. 1. Rolling processing principle Rolling processing is through the high hardness of ball (or roller), the surface of the parts of the extrusion, the workpiece surface plastic deformation, the micro uneven pressure light, extrusion, so as to improve the surface hardness and reduce the surface roughness value. Conical rollers are generally used for deep hole rolling. 2. The structure of the rolling head 3. The amount of rolling interference directly affects the surface roughness, too large is easy to make the workpiece surface "peeling". General steel rolling interference in 0.1 ~ 0.12mm. Feed rate: f =0.15 ~ 0.25mm/r Rolling speed: υ=60 ~ 80m/min Cutting fluid: use oil cooling lubricant, generally available kerosene and vulcanized oil mixture. (1) Before rolling, the hole should be finished by floating boring cutter, surface roughness Ra≤5μm. (2) Before rolling, the hole wall should be cleaned to remove oil and chips, otherwise the rolling will produce "pitting", affecting the surface roughness. (3) The number of rolling should not be more than 2 times, otherwise it will produce "peeling" phenomenon. (4) Cutting fluid must be filtered to ensure clean, no chips and debris. Six, hole processing composite tool concept: hole processing composite tool is two or more of the same or different kinds of hole processing tools combined into one special tool. ,
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