淬硬齿轮的加工

毕业设计译文毕业设计译文 课题名称 课题名称 淬硬齿轮的加工淬硬齿轮的加工 专专 业 业 机械设计制造及其自动化机械设计制造及其自动化 班班 级 级 05 级级 6 班班 学学 号 号 06050619 姓姓 名 名 冯健均冯健均 指导教师 指导教师 王丽王丽 完成日期 完成日期 2009 04 20 吉林大学珠海学院机电工程系吉林大学珠海学院机电工程系 Hardened Gear Modern gear is the most common machines in a mechanical transmission the passing of the machine as a driving force and the main form of movement is an important foundation for machinery parts and components With the belt chain friction hydraulic mechanical transmission etc compared with the power range high transmission efficiency high circumferential speed transmission ratio accuracy long service life long size structure and other characteristics of small size Therefore it has become indispensable in many mechanical products of transmission parts gear drive machine is the modern machines is the most common form of mechanical transmission the passing of the machine as a driving force and the main form of movement is an important basis for mechanical products components With the belt chain friction hydraulic mechanical transmission etc compared with the power range high transmission efficiency high circumferential speed transmission ratio accuracy long service life long size structure and other characteristics of small size Therefore it has become indispensable in many mechanical products of the transmission components but also the proportion of machinery in the form of the largest transmission The design and manufacture of gear will have a direct impact on the level of mechanical performance and quality products As the gear in the industrial development in a prominent position with the result that gear is recognized as a symbol of industrialization The characteristics of gear In recent years although other mechanical components of the manufacturing technology and electric drive technology has made significant development but in the production of the dominant form of transmission is still a variety of gear Gear has the following advantages and disadvantages A Advantages 1 the instantaneous transmission ratio constant the higher the smooth working 2 the use of non circular gear the instantaneous transmission ratio changes may be required for design 3 changes in transmission ratio range in particular the use of planetary transmission the transmission ratio can be 100 200 single stage or slow down the growth rate for transmission 4 speed range gear from the circular speed V 0 1M S to reach 200m s or higher speed from n 1 r min to more than 20000r min 5 power transmission range high carrying capacity high speed gear transmission power of the transmission power can be achieved 50000kW or more low speed torque for heavy duty gear can reach more than 14 105N M 6 high transmission efficiency especially in high precision cylindrical gear pair and its efficiency can reach more than 0 99 7 structure such as the use of planetary gear drives differential gear drive less or harmonic drive the more narrow the parts can become a transmission line 8 easy to maintain B shortcomings 1 operate in vibration shock and noise and generate dynamic load 2 the role of non overload protection 3 The requirements of high precision gear tooth or tooth with special needs high precision machine tools special tools and measuring instruments to ensure that the complexity of manufacturing processes higher cost For power transmission gears and gear box the size requirements of smaller lower gear noise resulting in the demand for hardened gears and gear manufacturers to put forward a new method to explore the processing gear requirements Gear in the process of hardening heat treatment the materials and the stress changes in gear will usually have a deformation that is tooth teeth and pitch to the error This error will cause the tooth profile at the time of the transmission is incorrect mating thereby increasing the load resulting in gear noise Therefore after the hardening heat treatment of gear in general should be added finishing processes to work together Hardened gear finishing process can be divided into two types one is the use of non forming the cutting edge such as grinding gear the other which is formed with cutting edge gear such as hardened HRC48 53 Hobbing processing This article will focus on the hardware used for processing hobbing cutting edge carbide tools forming the finishing process Today s carbide materials coatings and hobbing machine tool technology has hardened roller gear technology plus workers have been significantly improved especially in the processing of less than or equal to the small and medium sized module 12DP gear they can afford the hardware generated by cutting the course of the great cutting force The selection of carbide hob Carbide hob species in the material specifications there has been major progress Ultra fine fine medium or large carbide particles have a product now In addition the carbide hob blank forming process technology have been significantly improved such as hot isostatic pressing HIP process the process under high temperature and high pressure an increase of the intrinsic combination of cemented carbide blank and increased hard flexural strength alloy In accordance with the provisions of ISO the entity applications carbide material can be divided into a number of different categories gear cutting tool is divided into K type and P type K type carbide have higher wear resistance P type is more good high temperature red hardness Grades K and P in the cemented carbide grades in each of the particle structure cemented carbide grades are different from the ultra fine particles and other particles Each brand has its own applications this is the structure and the associated particles In general the soft Hobbing K analog performance than P type K type carbide can be micro structure of the particles particle size less than 0 5 m and P type is not In the wear areas K type toughness better and live longer Hob grinding and renovation of the re Hob processing after a certain number of workpieces the blunt cutting edge change at this time must be re grinding After grinding the hob must maintain the original geometry cutting edge must be sharp the metallographic structure of the tool can not be due to overheating and damage grinding Therefore should be used for grinding carbide hob an oil based coolant it can not respond to chlorine and sulfur The hob scraper re grinding after the coating is not as rough for the physical hardware of the hob as an important roll Hob grinding carbide coating it is recommended that pre treatment to its edge Hob will be re grinding cutting surface to remove the original coating which will reduce the tool life Tool can be re painted the Usually for the TiN coating can be coated 3 to 4 times TiALN for TiCN and coating since the coating itself has a lot of internal stress so it is difficult to cutting edge in the re coating Through several TiN coating after coating will produce the level of non uniform conditions and the tendency of stratification off so must remove the original coating There are two ways to remove the cutting tool coatings chemical and physical retreat retreat Tu Tu Tu retired chemical removal of coatings on cemented carbide cutting tools is a delicate process requiring considerable operator proficiency Tu retreat over the chemical will not only remove the coating but also to wash soluble cobalt binder damage the microstructure of carbide materials Cutting edge of micro damage will have a jagged surface In addition James should be back on the hob axis and Taiwan with holes and marks for protection against damage Tu to the physical it must be carried out by the original tool manufacturer which involves the whole of the hob tooth re grinding Although the chemicals to be much more expensive back James but the hob is a new quality and life can be guaranteed The requirements of the hobbing machine In order to give full play to the hard alloy and the benefits of coating technology hobbing machine should be improved accordingly At present all the advanced gear hobbing machine according to the design of high speed hobbing the hob hobbing machine speed of more than 3000r min usually 5000r min the workpiece spindle speed to match speed with the hob In addition the machine has a very high dynamic stiffness and thermal stiffness Hobbing advanced design features some of the key as follows the use of composite resin bed in order to improve the machine s dynamic and static properties the high speed device with constant temperature hob spindle box high speed spindle workpiece can be dry and wet two kinds Hobbing technology with the number of photoelectric sensor driven systems linear rolling guide system high speed automatic feeding 2 3 seconds an area of compact in accordance with ergonomics design maintenance convenience Scraping technology used Whether it is mechanical or CNC hobbing machine can be carried out of the scrape on condition that the machine must be equipped with the workpiece to the tool drive system of automatic synchronization This allows the shaving process more economical with automatic up and down on the machine tool feed system is also very important Electronic non contact system on the issue of an analog pulse sensor to measure the tool spindle the workpiece spindle and gear position CNC machine tool controller for processing of these pulses and then the main axis of the workpiece relative to the location of the tool be adjusted so that the workpiece cutting hob tooth and the relative position of the correct relationship Scraping technology used in the coolant has many advantages in the shaving process providing coolant lubrication generated as a result of shaving is not a normal chip temperature control is extremely important The smaller chip 刮下 thin unlike the normal knife cuttings can be taken away as many calories so scrape coolant can be used to control the tool workpiece and machine tool system temperature coolant can chip and the workpiece from the tool away improved precision surface roughness increased tool life In the green rolling cut process the correct choice of tooth thickness margin is very important Choice recommend Shun hobbing milling because it receives the most thick chips which help to control the dynamic state of cutting process and improve tool life Experience has shown that cutting speed can be more than 200m min feed rate depends on the choice of surface finish to be achieved The typical range of feed 0 5 1 25mm r Tool displacement channeling knife method is also very important because only a rough scrape part of cutting edge cross section to withstand wear and tear In contrast in the green cutting process the finishing tool to assume a major part of the processing volume This means that when the scraper blade channeling volume should be greater such as 12 48DP gear for every blade of channeling 0 3 0 4mm Hob scraper selection Carbide hob scraper is divided into two categories 10DP or greater for the hob modulus are usually designed to have a negative cutting angle in front of the former when the cutting edge hardened when exposed to quenching reduces the the impact of hard alloy materials modulus for smaller gear you do not have a negative anterior horn Negative anterior horn of the shortcomings of the hob is difficult grinding Hob diameter decreased after grinding in order to get the correct angle on the negative before the bias should change the volume wheel When shaving the big modulus gear the tooth top outer diameter and is usually not part of the tooth root was Hobbing and asked tooth to tooth root have a smooth transition Shen to be cut and complete the transition radius to improve the tooth root bending strength modulus for large gear hob scraper ideal should be a flange For small modulus gear processing should be a standard hob Radial standard carbide hob anterior horn processing known as the re rolling cemented carbide hob cut rather than scrape which refers to the use of a negative anterior horn hob Hobbing hardware technical requirements and hardware scrape or cut carbide hob rolling again almost the same as the technical requirements the only difference is the use of the channeling strategy shift different knives Hard roll the chip removal required to spend a lot of energy The final energy into heat Try to remove these vital heat Every processing of a workpiece the hob bit channeling a full pitch When the hob bit channeling from start to finish after the hob should be moved to a location away from the original amount of the parts of bias The amount of bias depends on the hob of the design and application and its purpose is to contribute to hob wear the uniform Another difference is that the clamping system used As the great cutting force workpiece clamping fixture must be safe Processing results show that the same helical gear hobbing with carbide hard roll again the high quality of its gear tooth AGMA10 close to level and the tooth pitch to more than AGMA12 level wide roll hardened rough hardware of the helical gear plus workers and its very high precision gears tooth profile accuracy AGMA10 level and the tooth pitch to AGMA12 level can be achieved 360 毕业设计网 Conclusion At present many economists have explored ways to quench processing gear including the choice of materials soft processing methods heat treatment and hard finishing process so that spread of hardened gears to meet the high quality of the hardened gear gear requirements From one entity to carry out full Hardened Hardened workpiece rough greens plus is a new work process Rigid because of a better quality machine tools and cemented carbide tool material and coating to cut hardened roller to become an effective processing method From the factory the practical application of results show that the hardened Gear Hobbing hard roll process has broad application prospects 淬硬齿轮的加工淬硬齿轮的加工 齿轮传动是近代机器中最常见的一种机械传动 是传递机器动力和运动的 一种主要形式 是机械产品的重要基础零部件 它与带 链 摩擦 液压等机 械传动相比 具有功率范围大 传动效率高 圆周速度高 传动比准确 使用 寿命长 结构尺寸长 结构尺寸小等一系列特点 因此 它已成为许多机械产 品不可缺少的传动部件 也是机器中齿轮传动是近代机器中最常见的一种机械 传动 是传递机器动力和运动的一种主要形式 是机械产品的重要基础零部件 它与带 链 摩擦 液压等机械传动相比 具有功率范围大 传动效率高 圆 周速度高 传动比准确 使用寿命长 结构尺寸长 结构尺寸小等一系列特点 因此 它已成为许多机械产品不可缺少的传动部件 也是机器中所占比重最大 的传动形式 齿轮的设计与制造水平将直接影响到机械产品的性能和质量 由 于齿轮在工业发展中的突出地位 致使齿轮被公认为工业化的一种象征 齿轮传动的特点 近几年来 虽然其他机械部件的制造技术与电传动技术有了较大的发展 但在 生产中占主导地位的传动形式仍为各种齿轮传动 齿轮传动有以下优缺点 A 优点 1 瞬时传动比恒定 工作平稳性较高 2 采用非圆齿轮 瞬时传动比可按所需变化规律设计 3 传动比变化范围大 特别是采用行星传动时 传动比可到 100 200 单级 适用于减速或增速传动 4 速度范围大 齿轮的圆周速度可从 V 0 1M S 达到 200m s 或更高 转速 可从 n 1 r min 到 20000r min 以上 5 传递功率范围大 承载能力高 高速齿轮的传动功率的传动功率可达到 50000kW 或更大 低速重载齿轮的转矩可达到 14 105N M 以上 6 传动效率高 特别是精度较高的圆柱齿轮副 其效率可达 0 99 以上 7 结构紧凑 如使用行星传动 少齿差传动 或谐波齿轮传动 可使部件更 为缩小 成为同轴线传动 8 维护简便 B 缺点 1 运转中振动 冲击和噪声 并产生动载荷 2 无过载保护作用 3 要求齿轮的切齿精度较高或具有特殊齿形时 需要高精度机床 特殊刀具 和测量仪器来保证 制造工艺复杂 成本较高 用于动力传动的齿轮和齿轮箱 其尺寸要求更小 齿轮传动的噪音更低 从而导致对淬硬齿轮的需求 也给齿轮制造厂家提出了探索齿轮加工新方法的 要求 齿轮在淬硬热处理过程中 其材料组织及应力的改变 通常会使齿轮产生 变形 即齿形 齿向及齿距误差 这此误差将引起齿廓在传动时的不正确啮合 从而加大了载荷 产生齿轮噪音 因此 淬硬齿轮在热处理后 一般应添加一 道精加工工序 淬硬齿轮精加工工艺可分为两类 一类是采用非成形的切削刃 如齿轮磨 削加工 另一类则是具有成形的切削刃如淬硬齿轮 HRC48 53 滚削加工 本文将集中讨论用于硬滚齿加工的硬质合金刀具成形切削刃的精加工过程 当今的硬质合金材料 刀具涂层和滚齿机技术的发展 已使淬硬齿轮滚切加工 技术有了显著的提高 特别是在加工小于或等于 12DP 的中小模数齿轮时 可承 受硬切削过程中所产生的极大的切削力 硬质合金滚刀的选取硬质合金滚刀的选取 硬质合金滚刀在材料的品种规格上有很大进展 超细 细 中等或大颗粒 的硬质合金现在都有产品 此外 硬质合金滚刀毛坯的成形工艺技术也有了显 著提高 如采用热等静压 HIP 工艺 该工艺在高压高温下 增加了硬质合金毛 坯的内在结合力 提高了硬质合金的抗弯强度 按照 ISO 的规定 实体硬质合 金材料可按应用场合的不同分为若干类 齿轮切削刀具分为 K 类和 P 类 K 类 硬质合金有更高的耐磨性 P 类则有更好的高温红硬性 在 K 牌号和 P 牌号硬 质合金中 每种牌号硬质合金的颗粒结构是不同的 从中等颗粒到超细颗粒 每种牌号都有其应用场合 这是和颗粒结构相关联的 一般来说 对于软滚削 K 类比 P 类的性能要好 K 类硬质合金能得到微米级的颗粒结构 粒度小于 0 5 m 而 P 类则不行 在磨耗方面 K 类韧性更好 寿命更长 滚刀的重新刃磨和翻新滚刀的重新刃磨和翻新 滚刀加工一定数量的工件后 其切削刃变钝 此时必须重新刃磨 刃磨后 的滚刀必须保持原有的几何形状 切削刃必须锋利 刀具的金相结构绝不可因 磨削过热而受破坏 因而在刃磨硬质合金滚刀时应采用一种油基冷却液 它对 氯和硫不起反应 对于刮削滚刀 刃磨后的重新涂层并不象用于实体毛坯硬滚 的滚刀那样重要 硬质合金滚刀刃磨后涂层前 建议对其刃口进行预处理 滚刀的重新刃磨将会除去切削表面的原有涂层 这会减少刀具寿命 刀具 是可以重涂的 通常对于 TiN 涂层 可涂 3 4 次 对于 TiCN 和 TiALN 涂层而 言 由于涂层本身有很大的内应力 所以在切削刃上难以再重新涂层 通过几 次涂覆 TiN 涂层后 会产生高低不均匀的状况 并有分层脱落的倾向 所以原 有涂层必须去除 目前有两种方法可去除刀具涂层 化学退涂和物理退涂 用化学退涂去除 硬质合金刀具上的涂层是一种精细工艺 要求操作者有相当的熟练程度 过度 的化学退涂不仅将涂层去掉 而且还将溶洗钴结合剂 损坏硬质合金材料的微 观结构 切削刃的微观损坏将产生锯齿状表面 此外 在退涂时必须对滚刀轴 台 内孔及标志进行保护 以免损坏 而物理去涂 则必须由原刀具制造厂来 进行 它涉及到整把滚刀齿形的重新