应用于经济型数控机床的“软撞块”回零技术

针对某型国产磨齿机的数控砂轮修整器进行了优化设计,创新性地提出了“软撞块”回零技术的概念及其技术方案,并在该样机上成功实现了对行程仅1.5 mm的轴向进给轴的回零动作控制。从而为经济型数控机床的超短行程数控轴的回零控制提供了一种简单,有效、可靠、零成本的全新解决方案。

气动回转冲击式螺丝刀撞块的制造

气动回转冲击式螺丝刀由于造价低廉,拧紧效率高,被大量应用于汽车装配等不同的行业中。由于它结构紧凑,零件小,因而承受冲击的零件如撞块等就易发生损坏。这样制造厂家就需提供大量的备件。

西门子软件撞块功能在数控机床位置确认中的应用

在数控机床的编程调试过程中,为了避免机床附件和工件的损坏,有时候需要确认某些轴的位置,比如在数控落地铣镗床的自动换刀工程中就需要确认Y、Z、W及主轴的位置；又如带有交换工作台的机床，在工作台交换过程中需要确认坐标轴的位置；机床增加保护区等同样需要坐标轴的位置确认。确认轴位置的方法有很多，主要有以下三种。

3号电动剪撞块装配固定方法的改进

1 设备简介中板厂3号电动剪板机,型号为Q11-25×3800,长6700毫米,宽3560毫米,高为5000毫米,重85吨。该机的任务是剪切钢板的头和尾。中板厂三辊劳特式轧机生产的每块钢板的平均重量约为1.5吨。每块钢板需剪切头尾各一次。

广佛线列车车门螺母副撞块异常磨耗的分析及处理

广佛线地铁列车车门的螺母副撞块发生多起异常磨耗,极易导致S1行程开关越过螺母副撞块使车门不能打开或关闭,为此设计了新型螺母副撞块,有效解决了问题。

斜井人车制动时间的数值解法

介绍了斜井人车的制动原理，提出了精确计算制动时间的数值方法，编制了计算软件，并以国产某斜井人车为例进行了计算。计算结果与实测值非常接近。利用本文方法及软件可分析各设计参数对制动时间的影响。

基于换向阀控制的往复运动的五回路设计

在方向控制回路的研究中,连续往复运动的实现有多种方式和方法,文中主要探讨用行程换向阀来进行连续往复回路控制的五种方法。

优化矿井斜井人车的结构有效提高其防坠性能

本文以现有矿井使用的XRC型插爪式斜井人车为例,对其存在的不合理的结构进行了改进,在有效提高了斜井人车的防坠安全可靠性的同时降低了人车的维护成本。从根本上解决了斜井人车存在的问题,有利于矿井安全、高效、快捷的提升作业。

数控机床参考点故障分析

参考点,是机床上的固定点,加工轴的测量系统以此为基准。数控机床一经制造,即可产生并确认机械零点所在,所有测量系统均可以以机械零点为出发点。机床参考点确定后,各工件坐标系也随之建立了。手动或自动回机床参考点时,首先,回归轴以正向快速移动,当行程开关(或接近开关)碰上(或接近)撞块(即参考点)时,开始减速运行。当走到相对编码器的零位时,回参考点电机停止,并将此零点作为机床的参考点,回参考点有故障时,都要根据这个原理进行排除。

专利

本实用新型涉及一种基于C型轨安装的可调式十字型重型限位开关，包括壳体。壳体内部置有撞块，撞块内部中心处安装有转轴，转轴一端伸出所述壳体的外部，转轴上安装有撞尺，撞尺在受力情况下能够旋转一定的角度，撞尺位于所述壳体的外部，转轴通过齿轮啮合于所述撞块上，撞块连接有复位弹簧。

五工位全自动数控专机电气设计与开发

五工位全自动数控专机由一个回转工作台、五个工作工位和两个传输机械手组成，是一台全自动加工以及全自动上下料的专机。整台设备使用六套FANUC Power Matei-MODELD数控系统，并由SIEMENSS7300PLC完成总控制，通过Profibus-DP总线把机床各个站点上的信号连接起来，并成功应用了数控系统在专机开发上的一些特殊功能。

Geochemistry and Zircon U–Pb age of the Yao＇an pseudoleucite porphyry,Yunnan Province,China

The Yao'an Pb–Ag deposit, located in the Chuxiong Basin, western Yangtze Block, is an important component of the Jinshajiang–Ailaoshan alkaline porphyry–related polymetallic intrusive belt. This complex suite of rock bodies includes a vein of pseudoleucite porphyry within deposits of syenite porphyry and trachyte.The pseudoleucite is characterized by a variable greyish,greyish-white, and greyish-green porphyritic texture. Phenocrysts are mainly pseudoleucite with small amounts of alkali feldspar and biotite. In an intense event, leucite phenocrysts altered to orthoclase, kaolinite, and quartz.Both the pseudoleucite porphyry and the syenite porphyry samples were typical alkali-rich, K-rich, al-rich rocks with high LaN/YbNratios; enriched in light rare earth elements and large-ion lithophile elements, and depleted in high field strength elements; and with strongly negative Ta, Nb, and Ti(TNT) anomalies and slightly negative Eu anomalies—all characteristics of subduction-zone mantle-derived rock.We obtained a LA-ICP-MS zircon U–Pb age of 34.1 ± 0.3 Ma(MSWD = 2.4), which is younger than the established age of the Indian and Eurasian Plate collision.The magma derived from a Type-II enriched mantle formed in a post-collisional plate tectonic setting. The geochemical characteristics of the Yao'an pseudoleucite porphyry are powerful evidence that the porphyry'sdevelopment was closely linked to the Jinshajiang–Ailaoshan fault and to the Indian-Eurasian collision.

Collision Analysis of the Spar Upper Module Docking

In order to assess the possible collision effect, a numerical simulation for the upper module and spar platlbrm docking at the speed of 0.2 m/s was conducted by using the software ANSYS/LS-DYNA, and the time history of the collision force, energy absorption and structural defonamtion during the collision was described. The purpose was to ensure that the platlbrm was safely put into operation. Furthermore, this paper analyzes different initial velocities and angles on the Von Mises stress and collision resultant force during the docking collision. The results of this paper showed that the docking could be conducted with higher security. The data in this paper can provide useful references for the determination of the upper module＇s offshore hoisting scheme and practical construction by contrasting the numerical simulation results of the parameters on the docking collision.

The influence of Cretaceous paleolatitude variation of the Tethyan Himalaya on the India-Asia collision pattern

Identifying when, where, and how India and Asia collided is a prerequisite to better understand the evolution of the Himalayan-Tibetan Plateau. Whereas with essentially the same published paleomagnetic data, a large range of different India-Asia collision models have been proposed in the literature. Based upon the premise of a northwards-moving Indian plate during the Cretaceous times, we analyze the significant variations in relative paleolatitude produced by a nearly 90° counterclockwise(CCW)rotation of the plate itself during the Cretaceous. Interestingly, recent studies proposed a dual-collision process with a Greater India basin or post-Neo-Tethyan ocean for the India-Asia collision, mainly in the light of divergent Cretaceous paleolatitude differences of the Tethyan Himalaya between the observed values and expected ones computed from the apparent polar wander path of the Indian plate. However, we find that these varied paleolatitude differences are mainly resulted from a nearly 90° CCW rotation of a rigid/quasi-rigid Greater Indian plate during the Cretaceous. On the other hand, when the Indian craton and Tethyan Himalaya moved as two individual blocks rather than a united rigid/quasi-rigid Greater Indian plate before the India-Asia collision, current available Cretaceous paleomagnetic data permit only multiple paleogeographic solutions for the tectonic relationship between the Indian plate and the Tethyan Himalayan terrane. We therefore argue that the tectonic relationship between the Indian plate and the Tethyan Himalayan terrane cannot be uniquely constrained by current paleomagnetic data in the absence of sufficient geological evidence, and the so-called Greater India basin model is just one of the ideal scenarios.

Anatomy of composition and nature of plate convergence： Insights for alternative thoughts for terminal India-Eurasia collision

The pattern and timing of collision between India and Eurasia have long been a major concern of the international community. However, no consensus has been reached hitherto. To explore and resolve the disagreements in the Himalayan study,in this paper we begin with the methodology and basic principles for the anatomy of composition and nature of convergent margins,then followed by an effort to conduct a similar anatomy for the India-Eurasia collision. One of the most common patterns of plate convergence involves a passive continental margin, an active continental margin and intra-oceanic basins together with accreted terranes in between. The ultimate configuration and location of the terminal suture zone are controlled by the basal surface of the accretionary wedge, which may show fairly complex morphology with Z-shape and fluctuant geometry. One plausible method to determine the terminal suture zone is to dissect the compositions and structures of active continental margins. It requires a focus on various tectonic elements belonging to the upper plate, such as accretionary wedges, high-pressure(HP)-ultra-high-pressure(UHP) metamorphic rocks, Barrovian-type metamorphic rocks and basement nappes, together with superimposed forearc basins.Such geological records can define the extreme limits and the intervening surface separating active margin from the passive one,thus offering a general sketch for the surface trace of the terminal suture zone often with a cryptic feature. Furthermore, the occurrence of the cryptic suture zone in depth may be constrained by geophysical data, which, in combination with outcrop studies of HP-UHP metamorphic rocks, enables us to outline the terminal suture zone. The southern part of the Himalayan orogen records complicated temporal and spatial features, which are hard to be fully explained by the classic "two-plate-one-ocean" template,therefore re-anatomy of the compositions and nature for this region is necessitated. Taking advantage of the methodology and basic principles of plate convergence anatomy and synthesizing previous studies together with our recent research, we may gain new insights into the evolution of the Himalayan orogeny.(1) The Yarlung-Zangbo ophiolite is composed of multiple tectonic units rather than a single terminal suture zone, and a group of different tectonic units were juxtaposed against each other in the backstop of the Gangdese forearc.(2) The Tethyan Himalayan Sequence(THS) contains mélanges with typical block-in-matrix structures, uniform southwards paleocurrents and age spectra of detrital zircons typical of Eurasia continent. All of these facts indicate that the THS belonged to Eurasia plate before the terminal collision, emplaced in the forearc of the Gangdese arc.(3) The Greater Himalayan Crystalline Complex(GHC) and Lesser Himalayan Sequence(LHS) comprise complex components including eclogites emplaced into the GHC and the upper part of the LHS. Judging from the fact that HP-UHP metamorphic rocks are exhumed and emplaced in the upper plate, the GHC and the upper part of the LHS where eclogite occur should be assigned to the upper plate, lying above the terminal subduction zone surface. It is the very surface along which the continuous subduction of the India subcontinent occurred, therefore acting as the terminal, cryptic suture. From the suture further southward, the bulk rock associations of the LHS and Sub-Himalayan Sequence(Siwalik) show little affinity of mélange, probably belonging to the foreland system of the India plate. By the anatomy of tectonic features of all the tectonic units in the Himalayan orogen as well as the ages of the subduction-accretion related deformation, we conclude that the terminal India-Eurasia collision occurred after 14 Ma, the timing of the metamorphism of the eclogites emplaced into the upper plate. The development of rifts stretching in N-S direction in Tibet and tectonic events with the transition from sinistral to dextral movements in shear zones, such as the Ailaoshan fault in East Tibet, can coordinately reflect the scale and geodynamic influence of the India-Eurasia convergence zone.By conducting a detailed anatomy of the southern Himalayas, we propose a new model for the final collision-accretion of the Himalayan orogeny. Our study indicates that the anatomy of structures, composition, and tectonic nature is the key to a better understanding of orogenic belts, which may apply to all the orogenic belts around the world. We also point out that several important issues regarding the detailed anatomy of the structures, compositions and tectonic nature of the Himalayan orogeny in future.

Developing plate tectonics theory from oceanic subduction zones to collisional orogens

Crustal subduction and continental collision is the core of plate tectonics theory. Understanding the formation and evolution of continental collision orogens is a key to develop the theory of plate tectonics. Different types of subduction zones have been categorized based on the nature of subducted crust. Two types of collisional orogens, i.e. arc-continent and continent-continent collisional orogens, have been recognized based on the nature of collisional blocks and the composition of derivative rocks. Arc-continent collisional orogens contain both ancient and juvenile crustal rocks, and reworking of those rocks at the post-collisional stage generates magmatic rocks with different geochemical compositions. If an orogen is built by collision between two relatively old continental blocks, post-collisional magmatic rocks are only derived from reworking of the old crustal rocks. Collisional orogens undergo reactivation and reworking at action of lithosphere extension, with inheritance not only in the tectonic regime but also in the geochemical compositions of reworked products(i.e., magmatic rocks). In order to unravel basic principles for the evolution of continental tectonics at the post-collisional stages, it is necessary to investigate the reworking of orogenic belts in the post-collisional regime, to recognize physicochemical differences in deep continental collision zones, and to understand petrogenetic links between the nature of subducted crust and post-collisional magmatic rocks. Afterwards we are in a position to build the systematics of continental tectonics and thus to develop the plate tectonics theory.

Late Paleozoic reefs and their significance for tectonics and oil-gas exploration in the Hinggan-Inner Mongolia area

Many reefs of the Late Paleozoic have been discovered recently in the Hinggan-lnner Mongolia area. These reefs clearly are geographically extensive, and possess distinctive features and well-developed reef-facies. They have been found to contain five reef-building communities and were constructed in four periods. Colonial coral-algal reefs at Aohan and Chifeng represent a warm shallow-sea in the Carboniferous. Different reefs in the Xiwu Banner were formed in three periods： early Late Carboniferous, late Late Carboniferous and Early Permian. These reefs were built in warm sea conditions. Their buildup types include colonial coral frameworks, algae-buildings and lime-mud mounds. Bryozoan reefs in the Zhalaite and Dongwu banners were built in the late Middle Permian and thrived in a cold shallow-sea. All reefs grew independently on two kinds of sedimentary platforms, carbonate and carbonate-clastic mixed platforms. Four reef-forming periods occurred later from south to north, along a collisional course between the North China Plate and the Siberian Plate. These reefs can be arranged into three ＇reef-links＇ or reef zones that extend along plate margins. Among these, the Aohan-Chifeng reef-link indicates a northern margin of the North China Plate, the Zhalaite-Dongwu reef-link marks a southern margin of the Siberian Plate, and the Xiwu-Beishan reef-link reflects the former existence of some inter-plates. The strata of each reef-facies are thick and contain rich asphalt deposits. Overlapping and heteropic layers are very thick and contain dark oil/gas-rich horizons; TOC analyses verify that most of these are good hydrocarbon source rocks. This study shows that the study area is an excellent candidate for oil-gas exploration.

Mesozoic tectono-magmatic activities in South China:Retrospect and prospect

The South China Block was formed through the collisional orogeny between the Cathaysia Block and the Yangtze Block in the Early Neoproterozoic.The northern,western and southern sides of the South China Block were affected by disappearance of the Paleo-Tethyan Ocean during the Paleozoic.The southern and northern sides of the South China Block were respectively collided with the Indo-China Block and North China Block in the latest Paleozoic to form the basic framework of the Eastern China.The Eastern China has been affected by the westward subduction of the Pacific Plate since the Mesozoic.Therefore,the South China Block was influenced by the three major tectonic systems,leading to a superposed compound tectonics.The comparative study of the Mesozoic geology between the South China Block and its surrounding areas suggests that although the Mesozoic South China Block was adjacent to the subduction zone of the western Pacific,no juvenile arc-type crust has been found in the eastern margin.The main Mesozoic geology in South China is characterized by reworking of ancient continental margins to intracontinental tectonics,lacking oceanic arc basalts and continental arc andesites.Therefore,a key to understanding of the Mesozoic geology in South China is to determine the temporal-spatial distribution and tectonic evolution of Mesozoic magmatic rocks in this region.This paper presents a review on the tectonic evolution of the South China Block through summarizing the magmatic rock records from the compressional to extensional tectonic process with the transition at the three juncture zones and using the deformation and geophysic data from the deep part of the South China continental lithosphere.Our attempt is to promote the study of South China’s geology and to make it as a typical target for development of plate tectonic theory.