链轮的火焰精密切割

链轮采用机械加工,不仅浪费时间、材料,而且成本高。为此,东德中央焊接研究所研制一种新式的、F02/ZIS391型光电火焰切割机,可用于链轮、齿轮、齿条、传动齿轮以及任意结构形状部件的切割。切口表面质量符合要求。试验得出,切割质量与下列主要参数有关:导轨精度;行走机构和控制方法;行程控制;样板的尺寸精度;切割机、样板及毛坯的安装精度;切口位置及其切割方向的选择;工件的几何形状和尺寸;切割长度;材质及材料厚度;切割气体种类、纯度、压力;切割速度;割咀距工件表面距离等等。 F02/ZIS391光电火焰切割机具有工作效率高、节省材料、设备费用低等优点。该切割机装有固定部件、割炬定心装置,以达到精密切割的目的。F02/ZIS391新式光电火焰切割机主要     

板坯火焰切割机故障分析及改造

某钢厂连铸车间K7043火焰切割机机械系统常见故障表现为提升机构传动箱体断裂;介质系统常见故障表现为管道元器件堵塞、切割枪堵塞;电气系统常见故障表现为编码器故障、电缆损坏、接近开关故障。对切割机常见故障进行分析,表明提升机构传动箱体断裂为箱体存在应力集中造成;管道元器件堵塞为煤气中焦油析出造成,切割枪嘴堵塞为切割热态板坯渣子飞溅堵塞造成;电气系统常见故障多由于切割机工况复杂造成。随后对火焰切割机进行了适应性改造,提升机构传动箱体应力集中现象得到消除,介质系统管路元器件堵塞情况得到改善,缩短了切割枪嘴更换时间,降低了电气元件故障率。对其实际运行情况进行观察,切割机故障率得到明显降低。     

基于离心力的新型铝铜管切割装置的设计

针对铝铜管成型后采取传统单向锯片切割存在弯曲和切口飞边的问题，设计一种新型切割装置。该装置利用离心力作为径向进给力，在圆周方向均匀排列3把圆切刀，并在切刀后面布置离心块。在离心块旋转产生的离心力作用下，3把圆切刀随回转盘旋转的同时作向心运动，从而对铝铜管进行环切。现场使用结果表明：铝铜管受力均匀，变形小，切口平整。     

超大厚度钢锭火焰切割机数控系统软件设计

超大厚度钢锭火焰切割机是为切割大型铸锻件而设计的专用高档数控设备.由于铸锻件毛坯表面为不规则多边形或近似圆形,在传统进行水口和冒口切割时需要不断手动调整割炬高度来保持割炬与工件之间的距离恒定以保证切割效果.为保证全时自动切割,系统运用激光测距传感器采集工件表面形状信息,以IMAC运动控制技术为基础,采用基于组件技术的CAD制图控件和面向对象的软件开发方法设计了一种专用数控系统,实现了手动、半自动和自动的高效切割.     

可控硅直流无级调速靠模氧气切割机

工作原理由可控硅对直流电动机进行无级调速,经蜗轮蜗杆传动而带动切割机主动轮,在固定轨道上拖动切割机,实现可逆切割。切割机架上可装4个割炬,可同时切割两块盖板或腹板。该架在固定滑道上沿靠模同时可做横向或纵向运动,实现半自动切割(直线或曲线)。技术指标 1.最大切割速度:1.5米/分 2.切割钢板厚度:不受限制 3.切割精度:可达?3 4.切割效率:提高3～4倍     

铸件飞边自动切割机

对于品种多、批量小的铸件生产来说,飞边切除这个工作被看作是实现铸造生产自动化的一个难题。东京大学工学部产业机械工学专业千千岩研究室研制出一种能自动切割任何形状铸件飞边的设备。这台设备的工作程序是:首先跟踪并记录飞边位置,然后,使切割机构按照记录切割飞边。现在,虽已有能切割任何形状铸件的飞边     

悬挂支架成形整形模

<正> 图1为独立悬挂支架,焊接于车架纵梁上,由 4.5mm厚20钢钢板压制而成,零件总长350mm,总高 285mm,最宽处(加上弯边)为140mm,最窄处(无弯边)为50mm。该零件无论从纵向、横向和高度方向都是变化的,长度方向(纵向)呈转角不一的W形。宽度方向(横向)为形状不同、宽度不等的     

土自动切割机

在轰轰烈烈的大闹技术革命高潮中,我厂交阻焊車間焊工尚仁荣和郑兴試制成功一台由留声机改装的自动切割机,如图所示。这种自动切割机使用方便,小巧灵活,不用电源,可以无級調速,割縫光滑美观,质量完全合乎要求,每摇一次发条可切割长度达3米左右。自动切割机由下列部件組成:小車傳动机构利用留     

基于ADAMS的往复式切割机的柔性动力学分析

研究往复式切割机的传动效果,找到受力性能最好的曲柄、连杆长度关系,可提高收割机质量。参考往复式切割机刚性分析相关文献,联合Solid Works和ADAMS软件,对往复式收割机建模并进行了柔性分析。从仿真结果可知,与刚性机构相比,柔性机构存在启动冲击力,且相同结构的刚、柔机构惯性力也有区别。往复式切割机曲柄为38 mm时,应选择650 mm长度连杆,可使启动冲击力、惯性力及振动最小。     

激光切割机数控系统随动技术的研究

配备三菱M70数控系统的激光切割机切割头与板材之间必须保持一定距离。为实现激光切割头与板材间距离的自动调整与控制,提出采用随动技术驱动z轴的解决方案。在比较几种实现随动控制的方案的优缺点后,采用外部坐标系补偿的方案,给出系统硬件的配置并编制PLC程序。采用该技术能满足激光切割机的特殊要求,对该类型产品设计有指导意义。     

调直切断机切断系统设计与分析

针对广东省东莞某公司当前生产的高精度线材存在端部切口质量较差的问题,在分析现有锤击式调直切断机的基础上,针对其切断系统进行一种快换刀具切断模及切断液压系统的设计,并利用AMESim液压仿真软件对其切断效果进行仿真分析。结果表明:新的快换刀具切断模机构可有效解决切断时刀具口径与线材直径不一致而导致的线材端口质量问题;采用液压式代替锤击式的切断方式,通过液压夹紧机构使切断模切断线材时能随线材运动,可有效解决线材断面产生毛刺、弯曲变形、倾斜等缺陷问题。     

Virtual Design and Optimization of Machine Tool Spindles

An integrated digital model of spindle, tool holder, tool and cutting process is presented. The spindle is modeled using an in-house developed Finite Element system. The preload on the bearings and the influence of gyroscopic and centrifugal forces from all rotating parts due to speed are considered. The bearing stiffness, mode shapes, Frequency Response Function at any point on the spindle can be predicted. The static and dynamic deflections along the spindle shaft as well as contact forces on the bearings can be predicted with simulated cutting forces before physically building and testing the spindles. The spacing of the bearings are optimized to achieve either maximum dynamics stiffness or maximum chatter free depth of cut at the desired speed region for a given cutter geometry and work-piece material. It is possible to add constraints to model mounting of the spindle on the machine tool, as well as defining local springs and damping elements at any nodal point on the spindle. The model is verified experimentally.     

A fuzzy expert system for the design of machining operations

In this paper, a fuzzy expert system called Smart Assistant to Machinist, or SAM, is introduced. The system consists of four modules: a database, a cutter selection module, a cutting condition design module and a learning module. The database consists of four data files: work material data file, machine tool data file, machining plan data file (which defines desirable material removal rate, surface finish, cutting speed, feed, depth of cut, etc.) and cutter data file. The cutter selection module is developed based on fuzzy logic, in which the cutter selection is conducted in three steps. First, the input information is “fuzzyized” Next, using the fuzzy correlation functions, cutter grades and cutters are selected. Then, the selected grades and cutters are searched against the cutter data file to check the availability. The cutting condition design module is developed based on fuzzy non-linear programming and user interactive graphics. The learning module is developed so that users can fine-tune the fuzzy functions to further improve the performance of the system. The system has two distinct features: (1) it can select cutters and design cutting conditions based on partial and imprecise information, and (2) it selects commercial cutter products used on shop floors. The use of the system is demonstrated using two examples.     

Analytical modeling of acoustic emission for monitoring of peripheral milling process

This paper presents the development of an analytical model relating the acoustic emission (AE) energy content to the cutting process parameters in peripheral milling and the experimental verification of the effects of the cutting parameters on the AE energy measurement to assess the applicability of AE sensing to the monitoring of peripheral milling. The model consists of an oblique cutting component and a rubbing component. It includes the contribution from both the AE attributed to plastic deformation in the primary shear zone and the AE resulting from interfaces between chips and the rake faces of the cutting teeth, between the workpiece and the cutter periphery as well as between the cutter flank and the machined workpiece surface. The adoption of an effective shear angle and a mean fraction angle in the model formulation provides insight into the fundamental mechanism of the cutting process responsible for the generation of the acoustic emission. A numerical example following the model development and a series of peripheral milling tests show that the true mean square voltage of the AE signal from peripheral milling increases with the primary cutting parameters (cutter rotating speed, feedrate, axial and radial depths of cut). The result of this work suggests that the energy measurement of the AE signal can be effectively used for the monitoring of peripheral milling processes.     

Mechanics and dynamics of general milling cutters. Part II: inserted cutters

Inserted cutters are widely used in roughing and finishing of parts. The insert geometry and distribution of inserts on the cutter body vary significantly in industry depending on the application. This paper presents a generalized mathematical model of inserted cutters for the purpose of predicting cutting forces, vibrations, dimensional surface finish and stability lobes in milling. In this paper, the edge geometry is defined in the local coordinate system of each insert, and placed and oriented on the cutter body using the cutter's global coordinate system. The cutting edge locations are defined mathematically, and used in predicting the chip thickness distribution along the cutting zone. Each insert may have a different geometry, such as rectangular, convex triangular or a mathematically definable edge. Each insert can be placed on the cutter body mathematically by providing the coordinates of the insert center with respect to the cutter body center. The inserts can be oriented by rotating them around the cutter body, thus each insert may be assigned to have different lead and axial rake angles. By solving the mechanics and dynamics of cutting at each edge point, and integrating them over the contact zone, it is shown that the milling process can be predicted for any inserted cutter. A sample of inserted cutter modeling and analysis examples are provided with experimental verifications.     

利用大进给量铣削提升模具制造生产率的研究

大进给量统削(High Feed Cutting/HFC)工艺是一种以整个铁刀直径用全切削(α_e=D)的方式,同时采用较小的切削深度(即背吃刀量α_p)和很高的进给速度进行切削的高效切削工艺,有很高的材料切除率。其目的是显著缩短粗加工或半精加工的时间,因此,原则上大进给量铣削(HFC)是属于高效铣削(HPC)工艺的范围。常规的高效铣削(HPC)工艺是一种通过高的吃刀量(α_p,α_e)、高的进给速度(v_f)和切削速度(v_c)实现高材料切除率的切削工艺。而大进给量铣削(HFC)工艺,顾名思义,显然是专注于通过很高的进给速度实现工件多余材料去除效率,进而提高模具制造生产率的一种制造工艺。实现这种大进给量铣削工艺需要有特殊的刀具,为此,众多刀具供应商开发了具有能实现大进给量铣削的几何形状的刀具,以达到提高生产率的目的,其原理就是通过减小刀具主偏角进而增大刀具切削刃与工件接触长度来实现的。     

Fabrication of micro-electrodes by multi-EDM grinding process

In this study, a multi-EDM grinding process is adapted to fabricate micro-electrodes. Equipments such as a wire EDM machine and a traditional CNC-EDM machine are used for machining micro-electrodes. Rod electrodes of copper with diameter 3.0 mm were cut to be 0.15 mm on wire-EDM machine at first step. EDM grinding process was used to grind micro-electrodes to fine diameter bellow 20 μm on a CNC-EDM machine at second step. For EDM grinding, rotating mechanisms are mounted on both the WEDM machine and the CNC-EDM machine. A CCD camera is provided for viewing and for on-line dimensional controlling, when micro-electrodes were cutting. Fine electrodes could be processed to a smaller size using proposed two-steps EDM grinding process. Higher L/D ratio could be also achieved by this method. The processed fine electrodes can be used for drilling micro-holes, micro-deep holes, micro-milling, micro-punching, and manufacturing of micro-nozzles.     

石材桥式切割机数控系统的刀补研究

为了实现对石材轮廓的精确加工,不同刀具的刀补模块设计是开发数控系统的关键技术。通过对C机能刀补算法的研究,简述了刀补转接的几种类型及其判断算法,结合石材桥式切割机的加工特点,对锯刀、铣刀、磨刀的刀补算法进行了设计。采用PC+运动控制卡的硬件结构,以Visual C++作为开发软件,设计了石材桥式切割机的数控系统软件。运行石材桥式切割机的数控系统,对锯刀、铣刀、磨刀刀补进行仿真,并在工厂中进行加工测试。结果表明:该切割机能稳定运行,其刀补算法实现了自动刀具补偿功能。     

面向批量生产的复合装甲制孔工艺研究及装备设计

复合装甲由铝合金、纤维复合材料及工程陶瓷组合而成，具有良好的综合性能，但难以加工。论文基于复合装甲的破坏机理，分析了钻孔时几种典型加工缺陷及其产生原因，提出了充分冷却、施加预压力及控制切削力等对策，使用套料加工方式，采用合适的切削用量。确定刀具以人造金刚石为原料，烧结法制作，并给出了快速刃磨方法。设计了具备工件安装及提供预压应力双重功能的专用夹具，以及能够控制轴向切削力大小并实现较小进给量的专用机床。