A set of water powered excavation test system was developed for the comprehensive performance testing and evaluation of water powered percussive rock drill indoors. The whole system contains hydraulic power section, e...A set of water powered excavation test system was developed for the comprehensive performance testing and evaluation of water powered percussive rock drill indoors. The whole system contains hydraulic power section, electronic control system, test and data acquisition system, and assistant devices, such as guideway and drilling bench. Parameters of the water powered percussive rock drill can be obtained by analyzing testing data, which contain impact energy, front and back cavity pressure, pressure and flow in each working part, drilling velocity, frequency and energy efficiency etc. The system is applied to test the self-designed water powered percussive rock drill SYYG65. The parameters of water powered percussive rock drill with impact pressure of about 8.9 MPa are 58.93 J for impact energy, and 8.97% for energy efficiency, which prove the effectiveness of system.展开更多
High Speed Drilling Electrical Discharge Machining (HSDEDM) uses controlled electric sparks to erode the metal in a work-piece. Through the years, HSDEDM process has widely been used in high speed drilling and in manu...High Speed Drilling Electrical Discharge Machining (HSDEDM) uses controlled electric sparks to erode the metal in a work-piece. Through the years, HSDEDM process has widely been used in high speed drilling and in manufacturing large aspect ratio holes for hard-to-machine material. The power supplies of HSDEDM providing high power applica-tions can have different topologies. In this paper, a novel Pulsed-Width-Modulated (PWM) half-bridge HSDEDM power supply that achieves Zero-Voltage-Switching (ZVS) for switches and Zero-Current-Switching (ZCS) for the dis-charge gap has been developed. This power supply has excellent features that include minimal component count and inherent protection under short circuit conditions. This topology has an energy conservation feature and removes the need for output bulk capacitors and resistances. Energy used in the erosion process will be controlled by the switched IGBTs in the half-bridge network and be transferred to the gap between the tool and work-piece. The relative tool wear and machining speed of our proposed topology have been compared with that of a normal power supply with current limiting resistances.展开更多
A possibility of the efficient use of rotary percussive drilling to provide drilling smaller diameter holes(40–70 mm) both in mining and prospecting is disclosed herein. A new construction designed for the nipple thr...A possibility of the efficient use of rotary percussive drilling to provide drilling smaller diameter holes(40–70 mm) both in mining and prospecting is disclosed herein. A new construction designed for the nipple thread connection is described. The relative amplitude variation, change of power pulse time and energy in their propagation throughout the drilling tool are determined. A possibility of the efficient power pulse transfer along the drill string to the rock destruction tools with new nipple connections which allow automating the make-up and breakout system of drill pipe was supported by experiments.展开更多
A large number of pneumatic rock drills are being extensively used in a majority of mines in China nowadays, with a high noise level up to 125 dB(A) and large vibration and oil-fog on working-site, which can seriously...A large number of pneumatic rock drills are being extensively used in a majority of mines in China nowadays, with a high noise level up to 125 dB(A) and large vibration and oil-fog on working-site, which can seriously jeopardize manipulator’s body and mind. Aiming at improving drilling environment and labor safety condition, the production mechanism of noise of all sorts of rock drills including pneumatic hydraulic and water-powered rock drills and measures of reducing noise level of pneumatic rock drills in special were discussed and led to the conclusion of that the pneumatic rock drills should be eliminated step by step, the hydraulic rock drill should be developed at full speed and especially the water-powered rock drill should be studied and applied according to the situation of China. In addition, the reasons of why hydraulic rock drills have not yet been used extensively and spread wide areas in China were discussed. The main technical parameters of newly developed leg-supporting water-powered rock drill and the comparation of experimental data between pneumatic rock drill and hydraulic rock drill were listed. The experimental results show that water-powered rock drill possesses the same superior properties as hydraulic rock drill and its noise is less than 20 dB(A) than pneumatic rock drill and there is no oil-fog on the working-site and vibration is reduced largely; but its drilling speed is raised largely , its structure is simpler, and maintenance is convenient. Therefore, popularizing applying of water-powered rock drill will be an effective way of improving mine working environment according to the current situation of China.展开更多
现阶段我国节能减排的具体工作逐渐展开,机械设计中节能减排的研究方向主要围绕机械元件性能提升等方面开展。本文通过数字化平台实现无纸化高效设计,减少重复性开发,提升设计效率,达到减少碳排放的目标。动力头是旋挖钻机的核心部件,...现阶段我国节能减排的具体工作逐渐展开,机械设计中节能减排的研究方向主要围绕机械元件性能提升等方面开展。本文通过数字化平台实现无纸化高效设计,减少重复性开发,提升设计效率,达到减少碳排放的目标。动力头是旋挖钻机的核心部件,具有结构紧凑、噪声小和效率高的特点。针对动力头设计中计算复杂、效率低的问题,开发了旋挖钻机数字化设计平台系统,简化设计流程,缩短设计周期。系统基于Visual Studio 2019平台开发,采用MFC(Microsoft Foundation Classes)框架C++语言编写,将参数化设计、参数传递、参数化分析、工程图管理和数据库管理划分为不同的模块进行设计,实现了零部件参数化设计、有限元分析与工程图自动生成与管理功能的集成。通过调用APDL程序语言,将命令流整合进而构建了完整的有限元分析中的建模、分析、后处理的流程,将传统较为复杂的机械设计流程用程序编写的方式集成到平台,实现部分设计参数的平台自动选取。经验证,设计与测试结果一致,提高了数字化平台的自动化水平和设计效率,通过高效的设计流程实现节能减排的目标。展开更多
基金Project(2006AA06Z134) supported by the National High Technology Research and Development Program of ChinaProjects(50934006, 50904079) supported by the National Natural Science Foundation of China
文摘A set of water powered excavation test system was developed for the comprehensive performance testing and evaluation of water powered percussive rock drill indoors. The whole system contains hydraulic power section, electronic control system, test and data acquisition system, and assistant devices, such as guideway and drilling bench. Parameters of the water powered percussive rock drill can be obtained by analyzing testing data, which contain impact energy, front and back cavity pressure, pressure and flow in each working part, drilling velocity, frequency and energy efficiency etc. The system is applied to test the self-designed water powered percussive rock drill SYYG65. The parameters of water powered percussive rock drill with impact pressure of about 8.9 MPa are 58.93 J for impact energy, and 8.97% for energy efficiency, which prove the effectiveness of system.
文摘High Speed Drilling Electrical Discharge Machining (HSDEDM) uses controlled electric sparks to erode the metal in a work-piece. Through the years, HSDEDM process has widely been used in high speed drilling and in manufacturing large aspect ratio holes for hard-to-machine material. The power supplies of HSDEDM providing high power applica-tions can have different topologies. In this paper, a novel Pulsed-Width-Modulated (PWM) half-bridge HSDEDM power supply that achieves Zero-Voltage-Switching (ZVS) for switches and Zero-Current-Switching (ZCS) for the dis-charge gap has been developed. This power supply has excellent features that include minimal component count and inherent protection under short circuit conditions. This topology has an energy conservation feature and removes the need for output bulk capacitors and resistances. Energy used in the erosion process will be controlled by the switched IGBTs in the half-bridge network and be transferred to the gap between the tool and work-piece. The relative tool wear and machining speed of our proposed topology have been compared with that of a normal power supply with current limiting resistances.
基金supported by the research Grant within the framework of the Federal Target Program ‘Scientific and Academic Staff of Innovative Russia’ during the years of 2009–2013competitive activity 1.3.1. ‘Research conducted by young researchers, Ph.D. holders’, the project theme ‘Research of power pulse interaction in a drilling tool and in rock mass in underground borehole drilling’
文摘A possibility of the efficient use of rotary percussive drilling to provide drilling smaller diameter holes(40–70 mm) both in mining and prospecting is disclosed herein. A new construction designed for the nipple thread connection is described. The relative amplitude variation, change of power pulse time and energy in their propagation throughout the drilling tool are determined. A possibility of the efficient power pulse transfer along the drill string to the rock destruction tools with new nipple connections which allow automating the make-up and breakout system of drill pipe was supported by experiments.
文摘A large number of pneumatic rock drills are being extensively used in a majority of mines in China nowadays, with a high noise level up to 125 dB(A) and large vibration and oil-fog on working-site, which can seriously jeopardize manipulator’s body and mind. Aiming at improving drilling environment and labor safety condition, the production mechanism of noise of all sorts of rock drills including pneumatic hydraulic and water-powered rock drills and measures of reducing noise level of pneumatic rock drills in special were discussed and led to the conclusion of that the pneumatic rock drills should be eliminated step by step, the hydraulic rock drill should be developed at full speed and especially the water-powered rock drill should be studied and applied according to the situation of China. In addition, the reasons of why hydraulic rock drills have not yet been used extensively and spread wide areas in China were discussed. The main technical parameters of newly developed leg-supporting water-powered rock drill and the comparation of experimental data between pneumatic rock drill and hydraulic rock drill were listed. The experimental results show that water-powered rock drill possesses the same superior properties as hydraulic rock drill and its noise is less than 20 dB(A) than pneumatic rock drill and there is no oil-fog on the working-site and vibration is reduced largely; but its drilling speed is raised largely , its structure is simpler, and maintenance is convenient. Therefore, popularizing applying of water-powered rock drill will be an effective way of improving mine working environment according to the current situation of China.
文摘现阶段我国节能减排的具体工作逐渐展开,机械设计中节能减排的研究方向主要围绕机械元件性能提升等方面开展。本文通过数字化平台实现无纸化高效设计,减少重复性开发,提升设计效率,达到减少碳排放的目标。动力头是旋挖钻机的核心部件,具有结构紧凑、噪声小和效率高的特点。针对动力头设计中计算复杂、效率低的问题,开发了旋挖钻机数字化设计平台系统,简化设计流程,缩短设计周期。系统基于Visual Studio 2019平台开发,采用MFC(Microsoft Foundation Classes)框架C++语言编写,将参数化设计、参数传递、参数化分析、工程图管理和数据库管理划分为不同的模块进行设计,实现了零部件参数化设计、有限元分析与工程图自动生成与管理功能的集成。通过调用APDL程序语言,将命令流整合进而构建了完整的有限元分析中的建模、分析、后处理的流程,将传统较为复杂的机械设计流程用程序编写的方式集成到平台,实现部分设计参数的平台自动选取。经验证,设计与测试结果一致,提高了数字化平台的自动化水平和设计效率,通过高效的设计流程实现节能减排的目标。
