ZL50型装载机后车架镗夹具

ＺＬ５０（４０）型铰接式装载机后车架主要有三组孔系：连接前后车架的铰接孔;连接转向缸的后支座孔（转向孔）;连接副车架的支承架孔（支承孔）。如图１所示,三孔系间的精度要求是,转向孔组对铰接孔组的平行度０．１ｍｍ,铰接孔组对支承孔组的垂直度 ０．６ ｍｍ;孔组内部同轴度即两转向孔为 ０．０４ ｍｍ,两铰接孔为 ０．１５ ｍｍ。 后车架传统的加工方法是将副车架的支承架与转向缸后支座镗后焊接,整体组焊完后划线,在Ｔ６１１镗床上接线镗铰接孔。这种工艺流程的焊接变形大,没有统一的加工基准,使后车架各孔系的垂直度、…     

装载机后车架镗夹具设计与分析

铰接转向装载机后车架是整机的承载骨架，加工时主要考虑三组孔系：连接前后车架的铰接座孔（铰接孔），连接转向液压缸的后支座孔（转向孔），连接副车架支承架的支承架孔（连接孔）。孔系间的精度要求见图１，其中要求转向孔组对铰接孔组的平行度０．１ｍｍ，铰接孔组对连接孔组的垂直度０．６ｍｍ；孔组内部同轴度要求：两转向孔之间为Φ０．０４ｍｍ，两铰接孔为Φ０，１５ｍｍ。 一般对后车架的传统加工方法是：副车架支承架、转向液压缸后支座镗后焊接，整体组焊后划线，在Ｔ６１２镗床上按线镗铰接孔。这种工艺流程焊接变形大，没有…     

一种提高装载机前车架生产效率的工艺方法

前车架作为装载机大型关键核心结构件之一,是连接工作装置动臂(工作装置)、动臂油缸,转斗油缸、转向油缸、后车架、前车桥等的关键部件.因其组成零件多、结构复杂、各铰接孔的尺寸精度、表面粗糙度及空间形位误差要求高、制造工序多,生产周期长、大型镗床、铣床、钻床等加工设备占用量大等,一直是影响装载机产能的主要因素,本文介绍了一种可有效提高装载机前车架生产效率的工艺方法.     

平地机摆座合套孔钻孔工装设计与应用

平地机摆座的6组合套孔划线后在镗床上加工,孔距不能保证,且加工效率低.根据摆座的结构特点,设计装夹装置在钻床上加工,确保了合套孔的加工质量,提高了加工效率.     

高精度液压元件柱塞孔挤压成形工艺

某型号柱塞泵局部柱塞孔的结构,该类型孔具有孔径小、尺寸精度要求高、表面粗糙度极小的特点.该工件材料为HT300,以往采用的常规加工方法是先钻铰,最后钳工采用手工研磨孔的方法将孔加工成形,此方法虽基本上能满足孔的加工精度要求,但生产效率低,质量稳定性差,不利于实现批量化生产,为解决上述问题,我们在加工此孔时采用自制挤压刀挤压孔的新工艺方法,经实践证明,经挤压加工后孔的加工质量完全符合图纸精度要求,且加工效率得到大幅度提高.     

框架类零件同轴孔的加工

1问题的提出装载机上框架类零件如到车架支承架其上两孔的同轴度要求很高。如果其同轴度超差，造成此类零件及销轴偏磨，则会降低其使用寿命，严重影响产品的质量。因此这类零件的同轴度在加工过程中必须设法加以保证。2加工方法下面以副车架支承架为例（如图1），介绍几种框架类零部件通常采用的加工方法。（l）划线加工，即先划线，然后按线找正调头撞加工。这种加工方法效率较高，但由于找正时存在较大误差，故这种方法很难保证同轴度满足其设计要求。m用长螳杆与尾架联合螳孔。这种加工方法能保证被螳工件的同轴度，其缺点是螳杆较长、…     

保证加工精度的前车架镗铣胎

装载机前车架是安装各总成、部件的基础件，其加工精度将直接影响工作装置的稳定性和车架的使用寿命。其形位精度超差，轻则造成销轴偏磨、工作装置倾斜，重则损坏车架直至造成报废。因此，如何保证其形位尺寸的加工精度是一个亟待解决的问题。１加工方法分析下面以ＺＬ５０装载机前车架为例（图１），介绍几种常用的加工方法。（１）划线加工。即先划线，然后按线找正调头镗加工，这种加工方法效率较高，但存在缺陷较多，我公司生产的前车架原加工方法即采用这种方法，它主要存在以下缺陷：①前车架在Ｔ６１２镗床平台上是以填块定位进行镗…     

利用组合机床镗"大小孔"的工艺探讨

在工程机械产品的大型焊接件中,由于结构上的需要,经常采用一种俗称“大小孔”的阶梯孔结构。以铰接式装载机后车架为例,介绍了两种在组合机床上镗削这种阶梯孔的方法:单向进刀加工法和双向进刀加工法;后者又分为三种实施方案:换装刀具法、十字滑台移动法和单向刀盘加工法。分析了各种方法的优缺点并指出,应根据工件的具体结构、尺寸精度要求、机床使用成本等方面综合考虑,选择一种较为合理的工艺方法。     

一种刮销端面的实用工具

1问题的提出 我厂装载机后车贺镗加工是在卧式镗床Ｔ612上完成的，在加工过程中存在如下问题：①需要刮削的四个端面间距尺寸(609)过长(图1)，刀杆伸出量过长；②刮削端面尺寸(ф145)较大，由于刀头切削部分伸出较长且受力杆刚度影响，刮削端面时切削力较大，产生切削颤动，刮出的表面粗糙，且两平行表面加工后产生内凹现象(见图2)，使装配后的连接盘无法压紧孔内的关节轴承，造成装载机在工作过程中关节轴承上下窜动，铰接销磨损严重，关节轴承碎裂现象时有发生，更甚者导致后车架铰接孔磨大，造成车架的报废。因此，保证后车架端面的刮削精度就成为亟待解决的问题。     

一种刮削端面的实用工具

1　问题的提出　　我厂装载机后车架镗加工是在卧式镗床T612上完成的，在加工过程中存在如下问题：① 需要刮削的四个端面间距尺寸（609）过大（图1），刀杆伸出量过长；② 刮削端面尺寸（Φ 145）较大，由于刀头切削部分伸出较长且受刀杆刚度影响，刮削端面时切削力较大，产生切削颤动，刮出的表面粗糙，且两平行表面加工后产生内凹现象（见图2），使装配后的连接盘无法压紧孔内的关节轴承，造成装载机在工作过程中关节轴承上下窜动，铰接销磨损严重，关节轴承碎裂现象时有发生，更甚者导致后车架铰接孔磨大，造成车架的报废。因此，保证…     

平地机后机架工况分析与试验测试

平地机后机架是整机的主要结构件,其整体刚强度决定了整机的应用范围及工作能力.通过分析计算得出了平地机后机架受力状况恶劣的两种实际工况,并运用有限元分析法,得出了恶劣工况下,后机架上的危险区域分布,最后用模拟工况试验的方法得出了不同工况下危险区域的应力数值,验证了分析计算结果,同时也为平地机后机架的结构设计提供了依据.     

Insights into the radial water jet drilling technology – Application in a quarry

In this context, we applied the radial water jet drilling (RJD) technology to drill five horizontal holes into a quarry wall of the Gildehaus quarry close to Bad Bentheim, Germany. For testing the state-of-the-art jetting technology, a jetting experiment was performed to investigate the influence of geological heterogeneity on the jetting performance and the hole geometry, the influence of nozzle geometry and jetting pressure on the rate of penetration, and the possibility of localising the jetting nozzle utilizing acoustic activity. It is observed that the jetted holes can intersect fractures under varying angles, and the jetted holes do not follow a straight path when jetting at ambient surface condition. Cuttings from the jetting process retrieved from the holes can be used to estimate the reservoir rock permeability. Within the quarry, we did not observe a change in the rate of penetration due to jetting pressure variations. Acoustic monitoring was partially successful in estimating the nozzle location. Although the experiments were performed at ambient surface conditions, the results can give recommendations for a downhole application in deep wells.     

旋挖钻机在岩溶地区桩基施工中的质量控制要点

旋挖钻机作为一种高效、环保的绿色桩工设备,近几年在岩溶地区桩基工程应用所占比重逐年提高。但由于岩溶地区地质复杂多变,地下岩面起伏大,溶洞、土洞发育且分布不规则,地下水丰富甚至发展为地下暗河、暗沟。使旋挖钻机在钻进的过程中易出现塌孔、斜孔、卡钻、漏浆、喷涌等质量安全事故。预防和处理这些事故是岩溶地区旋挖钻机施工关键。本文对岩溶地区某工程采用旋挖钻机施工过程中对预防和处理事故的措施进行分析、总结,供类似工程借鉴。     

PY160平地机后桥半轴断裂故障分析

通过对PY160平地机后桥半轴进行室内台架疲劳试验,并对试样断口进行分析,得出PY160平地机后桥半轴易断裂故障的原因,提出了合理有效的改进措施。     

The return of drilling fluid in large diameter horizontal directional drilling boreholes

The return of drilling fluid (drilling mud) in large diameter horizontal directional drilling (HDD) boreholes is a very important issue related to mud pressure, cuttings transport and pull back force, but this problem has not been fully solved in previous research due to the complexity and uncertainty of downhole conditions. The calculation methods of mud pressure loss in the borehole annulus are briefly introduced and the equation using a Power Law model is adopted to study the drilling mud return. A typical reaming hierarchy of a large diameter HDD project has been used to study the return direction of drilling mud and volumes of drilling mud return to the exit and entry points. The research results disclosed that the drilling mud can return to both exit and entry points at the same time, with a large majority of the drilling fluid returning to the exit point if the reamer is closer to the exit point, and vice versa. A parametric study has been conducted to find out the effect of changing parameters in the calculation equation on the drilling fluid return. The drilling mud return for those boreholes with the exit point and entry point located at different elevations has also been discussed. Finally, different types of reamers and other factors such as borehole collapse and borehole shape were taken into the consideration of drilling mud return.     

预应力锚索在边坡加固工程中的应用

介绍使用预应力锚索加固大型边坡工程的实例。加固施工采用由瑞典Ａｔ－ｌａｓ公司ＭａｓｔａｎｇＡ－６６全自动、全方位、全液压钻机，干法造孔钻进时效达到百米，有效地控制了施工中孔壁坍塌和边坡失稳。钻孔的偏斜度低于３％，保证了锚固应力达到设计要求的最大值     

Modeling of annular fluid pressures in horizontal boring

Horizontal directional drilling (HDD) is minimally-intrusive construction method for installing underground utilities and pipelines. Today, HDD is becoming widely accepted as a cost-effective alternative to traditional open-cut construction. The occurrence of hydraulic fracturing, resulting in the migration of drilling fluid to the surface, has placed the HDD process under scrutiny, especially when considered for projects in environmentally sensitive areas. Hydraulic fracturing results when fluidic pressure within the borehole exceeds the shear strength or undrained cohesion of the strata. Models have been developed to predict borehole pressures; however, there is only limited information available on the properties of drilling returns obtained during HDD installations. A research program was undertaken to determine flow characteristics for drilling returns under a variety of soil conditions and bore penetration rates. Soil samples were gathered based on the Unified Soil Classification System (USCS) and their rheological properties were obtained for different drilling fluids and slurry densities. Presented in this paper is a methodology for predicting borehole fluid pressures over a wide range of project parameters that can be used as a guide to minimize the occurrence of hydraulic fracturing.     

桥墩开孔支承的有限元分析及局部补强

针对客运专线建设标准大大提高的现状,简要叙述了移动模架原位现浇箱梁的施工,提出了利用有限元分析软件分析桥墩开孔的支承应力及采取相应技术措施的方法,以保证施工顺利进行。     

大直径锚索孔钻进的新方法

在高边坡复杂地层施工大吨位锚索孔存在一些困难。本文介绍一种以潜孔锤跟管钻进和孔底扩孔相结合的施工方法，该方法可用较轻型的钻机钻进较大的锚孔。     

Automatic monitoring of rotary-percussive drilling for ground characterization—illustrated by a case example in Hong Kong

In mountainous regions comprising weathered soils and rocks, it is important to delineate the spatial distributions of geomaterials with different weathering and decomposition grades in depth. This paper presents a methodology to cost-effectively and accurately identify the subsurface zones of volcanic weathering. The methodology consists of in situ digital monitoring and a number of associated data analysis methods. The in situ digital technique is the drilling process monitor. It can automatically, objectively and continuously measure and record parameters associated with the full drilling process of a rotary-percussion drilling machine when it is being used to drill a production hole (such as probe holes and soil nail holes) in the ground. The data analysis methods are used to identify relevant factual data from the full drilling process data for zoning. The calculations are simple and straightforward tasks. Factual data presented in the paper illustrate that the proposed methodology can be a simple and cost-effective tool to record and utilize by-products of current normal drilling practice for ground investigation, geotechnical design and verifications, drilling construction management, as well as drilling quality control. The proposed methodology offers great potential in furthering the geotechnical knowledge and engineering practice in Hong Kong and many other mountainous regions comprising weathered soils and rocks. There is also significant potential for other applications in civil and mining engineering through estimation of the mechanical properties of rock from the monitored drilling data.