海底石油管道切割绳锯机的设计及其试验研究

介绍了用于切割海底石油管道的金刚石串珠绳锯机组成和工作原理;进行了串珠绳锯机主要装置的结构设计;对串珠绳锯机的液压动力系统的技术参数进行了计算和确定。通过金刚石绳锯机切割海底石油管道的试验,对记录数据分析后得到了串珠绳锯切向切削力与进给速度、串珠绳的耐磨损率与切削速度、串珠绳的耐磨损率与进给速度等之间的关系。得出了用金刚石串珠绳锯机切割海底石油管道是行之有效的切割方法这样的结论。     

水下金刚石绳锯耐磨损率的实验研究

为了实现海底石油管道切割作业,采用均匀设计方法对水下金刚石绳锯串珠绳的耐磨损率影响进行了试验研究.使用MINITAB软件,建立了主要工艺参数对耐磨损率的多元线性回归方程,进行了回归分析,求得了绳锯耐磨损率较为精确的经验公式.进一步探讨了水下金刚石绳锯耐磨损率的工艺规律,为满足绳锯机设计要求和优化工艺参数提供了理论依据.     

金刚石串珠绳耐用度经验公式的实验研究

为了实现海底石油管道切割作业,采用均匀设计方法对水下金刚石绳锯串珠绳的耐用度进行了试验研究.使用MINITAB软件,建立了主要工艺参数对耐磨损率的多元线性回归方程,进行了回归分析,求得了绳锯耐磨损率较为精确的经验公式.进一步探讨了水下金刚石绳锯耐磨损率的工艺规律,为满足绳锯机设计要求,优化工艺参数提供了理论依据.     

单层输油管道切割试验

利用金刚石串珠绳切割单层输油管道的试验条件,分析了单层输油管道的结构特点和串珠绳切割管道钢管部分的面积和切口宽度变化规律。通过对单层输油管道切割试验验证了采用金刚石串珠绳切割单层输油管道的可行性,测定了绳锯机的工作效率,考察了设备工作稳定性,观测了液压系统的工作状况,明确了金刚石串珠绳切割单层输油管道的操作规程。通过相关技术参数的检测和分析,找到了合理的切割工艺参数,客观评价了串珠绳的使用情况。     

用于水下作业的锯绳张力检测系统

为了使金刚石串珠绳锯能够完成海底输油复合管道的切割作业,通过锯绳张力的检测可以监控切割状态,保证切削与进给运动处于协调状态。文中分析了锯绳切割时的受力状态,采用力合成法设计了张力传感器的机械结构,提出了上、下单片机通讯的水下锯绳张力的检测方案;设计了检测张力传感器,介绍了受力检测工作原理,对传感器进行了标定和精度分析;进行了锯绳水下切割管道张力检测试验,结果验证了锯绳水下张力检测方法的可行性、可靠性。     

锯切花岗石过程中金刚石串珠的磨损特性

通过跟踪烧结式金刚石绳锯切割花岗石过程中串珠直径磨损及串珠表面金刚石磨粒的磨损,研究串珠的磨损规律,并建立金刚石串珠的磨损模型。进行金刚石绳锯切割花岗石试验,试验结果表明,在金刚石串珠锯切过程中,单颗串珠沿其轴向出现不均匀磨损。串珠前端的磨损量会明显大于串珠中、后端磨损量,串珠后端的磨损也略大于串珠中端的磨损,串珠呈现腰鼓状磨损;串珠前端金刚石磨粒的平均出露高度高于串珠中、后端的磨粒平均出露高度,但在岩屑的磨蚀作用下,串珠前端的高出露金刚石磨粒容易产生非正常脱落。串珠磨损可分为腰鼓形状成形及腰鼓形状保持两个阶段。在切削负荷及岩屑磨蚀的共同作用下,串珠前、中、后三个部分在两个阶段的磨损表现各不相同。串珠前端是以岩屑磨蚀为主,而对于串珠中端,则是主要承受切削负荷。串珠后端两种作用的影响程度相对较弱。     

水下金刚石绳锯机技术方案分析与设计

介绍了金刚石绳锯机的基本组成和工作原理,通过对国外海洋工程施工中金刚石绳锯机作业技术方案的分析,设计了适于海底油气管道切割的水下金刚石绳锯机。针对丝杠在水下易腐蚀的缺点,提出了利用连通器原理对丝杠进行密封的方法。这种类型的水下金刚石绳锯机将在海底油气管道维修工程中发挥更有效的作用。     

水下金刚石绳锯机切割单层油气管道冲击特性研究

在分析了切割单层管道时串珠的运动过程后,建立了串珠与管壁冲击瞬间串珠绳内部各质点的运动方程。采用有限元瞬态动力学分析方法,仿真了串珠绳内部各质点的位移和速度的变化规律,并计算了冲击瞬间串珠绳轴线各处的附加动应力。试验研究表明：与切割复合管道相比,切割单层管道时,切割过程中发生了较剧烈的冲击,切割时间大大延长,切割后的断面水平度比较低;适当增加每米串珠绳上串珠个数可以减轻冲击作用。     

金刚石串珠锯锯切工艺及磨损机理研究

在锯切试验基础上 ,研究了金刚石串珠锯锯切速度、进给速度与串珠绳磨损率、锯切力之间的关系 ,分析了金刚石串珠锯的磨损机理 ,并对实际锯切加工提出了建议。     

加工参量对金刚石绳锯切割振动特性的影响

利用六个激光位移传感器测量金刚石串珠绳切割花岗石过程中,加工弧区内串珠绳的振动信号,从频率和振幅两个方面分析了张紧力、导轮间距以及串珠绳直径等加工参量对串珠绳切割振动的影响。实验结果表明,加工弧区内串珠绳的振动频率主要由串珠绳线速度及单位长度串珠个数的乘积来决定,本实验中的加工参量对振动频率没有明显影响。随着张紧力减小和导轮间距的增加,弧区内串珠绳的振动幅度会随之增加;随着串珠直径的增加,相同加工参数条件下,串珠绳的振动幅值也有所增加。     

Research on electrochemical discharge-assisted diamond wire cutting of insulating ceramics

Insulating ceramics are difficult to cut because of their high hardness and brittleness properties. This research proposes an electrochemical discharge-assisted diamond wire method for cutting insulating ceramics. The high temperature generated from electrochemical discharge facilitates the spalling of ceramics by the moving diamond wire. Experimental results showed that the material removal rate (MRR) of the new cutting method increased compared with the conventional diamond wire cutting process. Besides, electrochemical discharge had limited influence on the surface roughness and the wear of diamond wire. Additionally, the influence of the process parameters (DC voltage, wire speed, and counterweight mass) on the MRR and surface roughness was analyzed through experiments. The results showed that the MRR and surface roughness initially increased and then decreased with the increasing DC voltage; however, the variation was little. The higher wire speed resulted in an increased MRR and had little influence on the surface roughness. The MRR and surface roughness increased with the increasing counterweight mass.     

Lubrication by Grinding Fluids at Normal and High Wheel Speeds

An investigation is described of the lubricating effects of various grinding fluids at both normal and high wheel speeds under geometrically similar conditions. Grinding fluids include air (dry), water, soluble oil in two concentrations, and cutting oil. Results indicate that the specific cutting energy and the attritious wear of the abrasive grains are reduced by lubrication, but the rubbing friction between the workpiece and the wear flats on the grains is not. With high wheel speed, the specific cutting energy is lower with all grinding fluids than with normal wheel speed, but the attritious wear rate is greater. These lubricating effects are related to results for G-ratio, surface finish, and burning conditions.     

A new sawing machine by diamond wire

Diamond wire is widely used for stone cutting; it is typically employed to extract a block in quarry and to square the block in a machining company. In particular, the frames to square or to cut the blocks present many technological limits, such as the high costs of the diamond wire, the frequent break of the diamond wire during cutting, the poor quality of cut surfaces, and the dangerous process and productivity lower than that of the same tool used in a quarry. The present work shows an innovative prototype machine to cut by a diamond wire which overcomes the aforementioned technological limits. The developed machine has a bridge frame among which two pulleys move the diamond wire as regards the stone block according with the feed speed. The diamond wire moves on the two pulleys with a cutting speed. A tensile force is applied to the wire that twists it during the contact with the stone, instead of keeping it along a straight direction parallel to the foundation of the machine. The twisting of the diamond wire makes the use of the wire itself more productive and safer, since the wear of each single bead during cutting is more uniform. Moreover, the resulting specific pressure acts on each bead along the arc of contact with the cut block and increases along the cutting direction from the entrance to the exit of the contact with the stone. The increasing of the specific pressure causes a bending of the diamond wire during the contact with the stone. The developed prototype was provided with a sensory system to measure both the cutting power and the tensile force of the diamond wire during experimental tests. In this way it was possible to verify the functionality of the prototype plant and, in the same time, to evaluate the productivity of the implemented cutting process.     

钎焊金刚石磨具加工石材时切削参数的试验研究

针对石材切削加工过程中切削参数的变化和选择,通过试验研究了磨削速度、进给速度和磨削深度对切削力的影响规律;研究了切削参数变化及磨削时间与刀具磨损之间的关系;显微观察了金刚石砂轮的磨损状况。试验结果表明,磨削力随着磨削深度和进给速度的增加而增大、随着磨削速度的增大而减小;在开始磨削至32延长米时,金刚石砂轮的磨损较大,在后续加工中砂轮磨损量随着磨削参数的增大而平缓增加,当加工到480延长米时,砂轮磨损量又明显增加。     

陶瓷轴向磨削加工实验分析及砂轮磨损研究

轴向磨削加工是以金刚石小砂轮的端部磨粒作为主切削刃来去除材料,用圆周部分内圆或外圆表面磨粒作为副切削刃对已加工圆柱面进行修磨的一种磨削加工技术。从轴向对工程陶瓷进行外圆或内孔加工时,一次切削的径向磨削深度(即背吃刀量)与进给速度分别可达5～10mm和200mm/min以上,实现了工程陶瓷外圆的高效低成本加工。利用该方法对陶瓷材料制成的发动机精密偶件出油阀套筒进行内孔加工,通过单因素试验,分析了不同参数组合下的砂轮磨损情况及各参数对砂轮磨损的影响,试验表明:砂轮磨损程度随磨削深度的增加而呈非线性增加;为使砂轮磨损最小化,主轴转速和工件转速应匹配,即二者的比值应控制在一定的范围内。