The hole is used as the most common mechanical parts and the most commonly used features, plays a different role and use, a positioning hole, hole, hole, base assembly process hole, hole accuracy and requirements are different, in the application of advanced numerical control equipment at the same time, the traditional processing technology will be of great potential hole impact of hole machining process, tool, etc. also change, replaced by milling drilling, milling instead of hinges, replaced by milling boring are also generated, in improving the machining quality and production efficiency at the same time, we should continuously explore processing hole, looking for a new processing method, improve manufacturing the level of. This paper is based on the summary of the hole machining experience, trying to take this as an example, analysis and found that the general law of hole machining, the process of drilling, reaming, boring, milling, analysis of the pros and cons of each process, the process is intended to explore the high quality high precision processing, find out simple and feasible methods of technical analysis.

孔是机械零件上极为常见的特征，在许多类零件上都带有孔。据其使用特性及作用不同，加工时的尺寸精度及表面质量大不一样，然随着三轴联动数控铣床及加工中心的不断应用，孔的加工工艺也发生着重大的变化，孔的加工不再以钻削加工为主了，取而代之的是工艺集中的复合加工工艺，既便如此，也不能说一个高精度要求的孔的加工工艺是固定一尘不变的。北京机床研究所副总工艺师金福吉一针见血地指出：“我国孔加工的工艺跟质量落后发达国家30年一点也不为过，究其原因，就在于孔的加工工艺的落后。”实际上，孔的加工是刀具在工件内部进行，切屑的排除、散热、观察都比较困难，孔的大小又限制了刀具的大小，孔的精度也限制了刀具的精度等级，测量内孔的尺寸又不方便。由此可见，在传统孔加工工艺的基础上，急需新的孔加工工艺，这些均要求加工人员要重视孔的加工工艺和各种特点。

Holes are the most common feature of mechanical parts, with holes in many types of parts. According to the characteristics and function of different size, accuracy and surface quality when machining large are not the same, but with the continuous application of three axis CNC milling machine and machining center, machining holes have been changed, the machining of the hole drilling to no longer dominated, replaced by a composite processing the process of centralized process, even so, can not say that the processing technology of a high precision hole is fixed in the same. Beijing Machine Tool Research Institute Vice General Engineer Jin Fuji pointed out: "China's hole processing technology with the quality behind developed countries in 30 years is not an exaggeration, the reason lies in the process of the hole behind." In fact, the machining of the hole is a tool inside the workpiece, it is difficult to eliminate, heat dissipation, observation of the chip, the size of the hole and limit the size of the tool, the accuracy of the hole also limits the precision of cutting tool, measuring the pore size and is not convenient. Thus, on the basis of the traditional hole processing technology, new hole processing technology is urgently needed, which requires the processing staff to pay attention to the processing technology and characteristics of the hole.

一、钻削加工

Drilling

1.所用刀具

1. cutters

刀具有普通麻花钻、可转位浅孔钻、扁钻等。在加工中心上钻孔，大多数采用普通麻花钻。麻花钻有高速钢和硬质合金两种。麻花钻的组成，它主要由工作部分和柄部组成。工作部分包括切削部分和导向部分。

The utility model has an ordinary twist drill, an indexable shallow hole drill and a flat drill. Most of the drill holes in the machining center are made of plain twist drills. There are two kinds of twist drills: high speed steel and hard alloy. The composition of a twist drill is mainly composed of a work part and a handle part. The work section includes a cutting section and a guide portion.

麻花钻的切削部分有两个主切削刃、两个副切削刃和一个横刃。两个螺旋槽是切削流经的表面，为前刀面;与工件过渡表面(即孔底)相对的端部两曲面为主后刀面;与工件已加工表面(即孔壁)相对的两条刃带为副后刀面。前刀面与主后刀面的交线为主切削刃，前刀面与副后刀面的交线为副切削刃，两个主后刀面的交线为横刃。横刃与主切削刃在断面上投影间的夹角称为横刃斜角，横刃斜角Ψ=50°—55°;主切削刃上各点的前角、后角是变化的，外缘处前角约30°，钻心处前角接近0°，甚至是负值;两条主切削刃在与其平行的平面内的投影之间的夹角为顶角，标准麻花钻的顶角2ψ=118°。

The cutting part of a twist drill consists of two main cutting edges, two auxiliary cutting edges and a transverse blade. The two is a spiral groove surface cutting through the rake face and the workpiece surface; the transition (i.e., hole bottom) two surface opposite ends of the main flank; and the machined surface (i.e., hole wall) two blade with relatively minor flank. The intersection of the rake face and the main flank is the cutting edge, the intersection of the rake face and the vice flank is an auxiliary cutting edge, and the intersection line of the two main flank faces is a transverse blade. The main cutting edge and chisel edge projection in the section called the angle between the rake angle, rake angle is =50 degrees to 55 degrees; the main cutting edge on the front angle, the angle is changed, the outer edge of front angle of about 30 degrees, a former angle close to 0 degrees, even negative the angle between the projection; the two main cutting edge plane in parallel with the wrench, the standard twist drill angle 2 degrees w =118.

麻花钻导向部分其导向、修光、排屑和输送切削液作用，也是切削部分的后备。

The guiding part of the twist drill is the guiding, trimming, chip removing and conveying cutting fluid. It is also the backup of the cutting part.

根据柄部不同，麻花钻有莫氏锥柄和圆柱柄两种。直径为8—80mm的麻花钻多为莫氏锥柄，可直接装在带有莫氏锥孔的刀柄内，刀具长度不能调节。直径0.1—20mm的麻花钻多为圆柱柄，可装在钻夹头刀柄上。中等尺寸麻花钻两种形式均可选用。

There are two kinds of twist drills: Morse taper shank and cylindrical shank according to the shank. The diameter is 8 80mm for Morse taper shank twist drill, can be directly installed in the handle with Morse taper, tool length can not be adjusted. 0.1 to 20mm diameter twist drills are mostly cylindrical and can be mounted on the handle of the drill chuck. Medium size twist drills are available in either of two forms.

2.工艺特性

2. process characteristics

钻削为孔加工中必不可少的粗加工阶段，该阶段主要考虑的是材料的去除，这一过程主要靠机床主轴的轴向应力进行切削的，所以说切屑是挤出来的，因此，以钻为主的粗加工就会有切屑缠绕与孔内壁处变形大这一结果，在这一过程中重点考虑的是解决钻尖的冷却与切屑的缠绕，也就是说，以钻为主的加工考虑的就是效率，而对孔而言，无法保证孔的加工质量，即便是用钻头自小而大扩孔，亦不能解决挤压造成的变形问题。可以这么说用钻头以钻削加工为主，仅用于粗加工和半精加工阶段，不允许用此工序完成一个孔的精加工。这一阶段钻头的选用一般都要小于孔的尺寸，一旦选用和孔尺寸一致大小的钻头，该孔的加工势必报废。

Drilling for rough machining stage essential in hole machining, the main consideration is the removal of materials, this process mainly depends on the axial stress of machine tool spindle cutting, so that the chip is squeezed out, therefore, will be based on drilling rough machining with cutting around with this result the hole inner wall deformation, considering the key in this process is to solve the winding drill cooling and chip, that is to say, the drill processing to consider is the efficiency of hole, can not guarantee the quality of hole, even a bit from and reaming, also cannot resolve the problem of deformation squeeze caused by the. It can be said that the drill is mainly used for drilling and is only used in rough and semi finishing stage. This process is not allowed to finish the finishing of one hole. In this stage, the selection of the drill bit is usually smaller than the size of the hole. Once the size of the drill is the same size as the hole size, the processing of the hole is bound to be scrapped.

二、铰削加工

Two 、 reaming

1.所用刀具

1. cutters

机用铰刀。通用标准机用铰刀。

Machine reamer. Universal standard machine reamer.

铰刀工作部分包括切削部分与校准部分。切削部分为锥形，担负主要切削工作。切削部分的主偏角为5°—15°，前角一般为0°，后角一般为5°—8°。校准部分的作用是校正孔径、修光孔壁和导向。为此，这一部分带有很窄的刃带(γo=0°，αo=0°)。校准部分包括圆柱部分和倒锥部分。圆柱部分保证铰刀直径和便于测量，倒锥部分可减少铰刀与孔壁的摩擦和减少孔径扩大量。

The work part of the reamer includes the cutting part and the calibration part. The cutting part is taper and bears the main cutting work. The main deflection angle of the cutting part is 5 degrees to 15 degrees, the front angle is generally 0 degrees, and the back angle is generally 5 degrees to 8 degrees. The function of the calibration section is to calibrate the aperture, trim the hole wall and guide. For this reason, this part has a very narrow blade band (o=0 o=0). The calibration section comprises a cylindrical portion and an inverted cone portion. The cylindrical part ensures the diameter of the reamer and is easy to measure, and the inverted cone part can reduce the friction between the reamer and the hole wall and reduce the aperture enlargement.

标准铰刀有4—12齿。铰刀的齿数除了与铰刀直径有关外，主要根据加工精度的要求选择

Standard reamers have 4 - 12 teeth. In addition to the diameter of the reamer, the number of teeth in the reamer is mainly selected according to the requirements of machining accuracy