带锥齿蜗轮蜗杆传动式消防水炮结构设计及流场仿真（英文）

通过理论计算设计一种带锥齿蜗轮蜗杆传动式消防水炮,详细介绍了所设计消防水炮的工作特点,重点阐述了消防水炮整体结构及关键部件的设计,并对消防水炮内流道流场特性进行了仿真分析。仿真结果与预期效果基本吻合体现出了设计的合理性,相关分析结果可为消防水炮结构设计和性能优化提供一定的参考。     

水力自摆式消防水炮的设计及流场仿真

在理论计算的基础上设计一种水力自摆式消防水炮,详细阐述水力自摆机构的工作原理及组成.利用Fluent流场仿真软件对该消防水炮内部流场特性进行了仿真,仿真结果表明所设计的消防水炮能满足其射程和流量的要求,同时也为其他规格和类型的消防水炮设计提供参考.     

采用阀控缸进行自动换向控制的移动式消防水炮动态特性研究(英文)

消防水炮是消防作战中主要灭火装备之一.设计了一种移动式消防水炮,采用阀控缸水力自动换向控制装置,利用自身水压力驱动水液压缸带动水炮炮头摆动,并采用机械反馈装置使炮头自动换向.采用Fluent流场仿真软件对水炮流道结构进行仿真分析.结果表明,所设计消防水炮水力学性能较好,结构设计比较合理.利用AMESim液压机械仿真软件对该水力自摆控制系统进行建模仿真分析.仿真结果表明,该水力自摆系统能够在水压力驱动下以一定的频率进行自动换向,并且在水压力升高的情况下,其摆动频率也会上升.实验验证该水炮能满足灭火覆盖范围和射程的要求,炮头自动换向频率也能满足设计要求.所设计的带阀控缸自摆装置的移动式消防水炮特别适用于无人操作、消防人员难以进入的消防场合.     

水力自摆移动式消防水炮结构设计及数值模拟研究

设计一种水力自摆移动式消防水炮,采用阀控缸系统作为水力自摆控制系统,利用自身水压力驱动水液压缸带动水炮炮头摆动,并采用机械反馈装置使其自动换向.采用Fluent流场仿真软件对水炮流道结构进行仿真,具体分析了不同进水口压力和不同炮身直径对出口速度的影响规律,结果表明:所设计的消防水炮水力学性能较好,结构比较合理.初步实验验证了该水炮能满足灭火覆盖范围和射程的要求.其相关结论也可为其他规格类型的消防水炮设计提供参考.     

消防水炮结构的设计及水射流特性的分析

消防水炮是消防作战中的主要装备。它能将水的静压能转化为动能,喷射出各种水流或水雾,用于灭火、冷却、隔热和排烟等消防作业。介绍了消防水炮的分类及工作特点,重点阐述了消防水炮整体结构及关键部件的设计,尤其对消防水炮的流道与喷嘴的结构进行了阐述,并对消防水炮水射流特性及影响射流的因素进行了详细分析。结果表明:消防水炮的结构及工作参数对其射流性能有很大影响;在一定压力范围内,消防水炮进出口截面不变,进口压力越大,消防水炮的流量也越大,可以提高水流出口速度来增加消防水炮的射程,扩大其保护范围。相关分析结果可为消防水炮结构设计和性能优化提供一定的参考。     

消防水炮喷嘴流场数值模拟研究

消防水炮是消灭大型火灾的关键工具,正在向大流量、远射程和高射高等方向发展。喷嘴作为消防水炮的核心部件之一,其设计直接决定射流性能的优劣。采用Fluent对3种不同内轮廓线结构的消防水炮喷嘴进行流场数值模拟,分析结构形式对射流压力、速度和湍动能的影响,从而确定消防水炮喷嘴的最佳内轮廓线结构。通过实验结果可知,在流量为40、50、60和80 L/s的情况下,采用正弦形式的喷嘴内轮廓曲线的射程高于国标规定射程15%以上。以上研究可为提高消防水炮射流性能提供参考。     

管廊消防巡检机器人设计与分析

针对综合管廊的安全运维与管理的需求,设计一种集巡检和消防灭火功能于一体的管廊消防巡检机器人。该机器人由机器人本体、灭火器、机械臂和智能检测系统构成。介绍了机器人的总体结构及功能,建立了机械臂的D-H坐标系,对机械臂进行正、逆运动学分析。运用蒙特卡洛法及MATLAB软件对机器人机械臂的工作空间进行仿真与分析,得到不同情况下的机械臂末端的工作空间,仿真结果验证了机械臂可灵活满足机器人的工作要求,为后续管廊消防巡检机器人的控制工作和优化设计奠定了基础。     

基于CFD的液氮消防喷嘴两相流数值分析

为了研究液氮消防喷嘴的射流特性,对氮气和水混合喷射的两相流喷嘴建立数学模型和几何模型,利用计算流体力学的方法对气液两相流射流流场的速度、压力、密度等物性参数进行数值模拟仿真分析。并改变喷嘴的入口、出口以及总长度等参数进行仿真,对比不同参数时的射流速度,从而得到喷嘴的最佳尺寸参数。压力仿真云图的结果表明,喷嘴弯折处易出现负压,因此在设计时应将喷嘴设计成曲线型。     

室内大空间喷水灭火系统自动寻的关键技术分析

随着我国社会经济的飞速发展,大空间建筑室内火灾预防和处置问题日益突出,传统消防灭火装备相对滞后,无法满足大空间建筑室内消防灭火的的要求。为此,设计了一种室内大空间自动寻的喷水灭火系统,该系统采用蜗轮蜗杆传动和齿轮传动两级传动方式实现水平和俯仰方向运动,利用火灾探测器进行火灾实时监测,16位单片机SPCE061A作为主控制器,根据火灾探测器信号控制传动机构完成火灾的空间定位。建立了水流轨迹方程并进行了仿真分析,具体分析了工作压力、俯仰角度及安装高度对水流射程及落地速度的影响。仿真和现场测试表明,所设计的喷水灭火系统具有低报错率,火灾监测和定位方法简便可行,运行稳定、及时、准确的特点,能满足大空间火灾的预防和处置要求。     

新型消防机器人悬挂系统建模与仿真分析

为提高消防机器人的平稳性和可靠性,利用动力学软件ADAMS建立某新型消防机器人单轮悬挂系统动力学模型。基于履带式移动机器人动力学与冲击碰撞原理,在MATLAB/Simulink中建立随机路面激励模型,简化平面数学模型建立基础,并对单轮悬挂系统进行参数化分析。在D级随机仿真路面条件下进行运动学分析与动力学仿真分析,研究扭杆-液气减振器对消防机器人悬挂系统性能影响。结果表明:扭杆-液气减振器悬挂系统模型简单、平稳、可靠,具有非线性、变阻尼等特性。     

渐开线塑料齿轮模具设计技术

介绍了渐开线塑料齿轮注塑模具设计的关键技术。着重对齿轮模具的型腔设计、浇口设计及材料选用等方面进行了详细阐述,对渐开线塑料齿轮的模具设计进行了分析。结果表明,齿轮精度高,啮合情况好。     

Cutting force model for gear honing

In gear honing the low robustness of the process is a challenge in process design. The forces resulting from the machining interact with the dynamic behavior of the system which influences the quality of the workpiece and the tool life. Due to these reasons, the process forces during gear honing must be determined locally and temporally resolved. Therefore, a force model was derived and parameterized with gear honing analogy trials. This force model was combined with a process simulation for gear honing and an analytical calculation of the velocities. The model for gear honing was validated with gear honing trials.     

纯滚动单圆弧齿轮的模态分析

纯滚动单圆弧齿轮是一种新型的圆弧齿轮,为了研究其振动特性,利用Pro/E建立纯滚动单圆弧齿轮的三维实体模型,然后导入到ANSYS中对该齿轮进行模态分析,分别得到纯滚动凸圆弧齿轮和凹圆弧齿轮的固有频率、振型及临界转速;讨论了不同齿数、模数、螺旋角情况下齿轮的固有频率,讨论结果为纯滚动单圆弧齿轮的优化设计和动态响应分析研究提供基础。     

Development of an on-line tool-life monitoring system using acoustic emission signals in gear shaping

Sensing techniques for monitoring machining processes have been one of the focuses of research on process automation. This paper presents the development of on-line tool-life monitoring system for gear shaping that uses acoustic emission (AE). Characteristics of the AE signals are related to the cutting condition, tool material and tool geometry in the cutting of metals. The relationship between AE signal and tool wear was investigated experimentally. Experiments were carried out on the gear shaping of SCM 420 material with a pinion cutter having 44 teeth. Root-mean-square (RMS) AE voltages increase regularly according to tool wear. It is suggested that the maximum value of RMS AE voltage is an effective parameter to monitor tool life. In this study, not only the acquisition method of AE signals for rotating objects but also the signal-processing technique were developed in order to realize the in-process monitoring system for gear shaping. The on-line tool-life monitoring system developed has been successfully applied to gear machining processes.     

变位齿轮泵基本参数的可视化计算

齿轮变位后齿轮泵的设计，若按常规方法进行，不仅步骤繁琐、计算工作量大，而且容易出错。为解决此问题，本文开发了基于Visual Basic可视化编程语言的齿轮泵基本参数计算软件，利用该软件可以方便地对齿轮泵进行交互式、系列化设计，对于加快齿轮泵的技术革新、提高企业产品的变型开发能力具有现实意义。     

Shrink fit design for precision gear forging dies

The usual way to shrink fit design for precision forging of gear dies is to use thick wall cylinder theory (analytical approach) assuming that bore diameter is equal to pitch diameter by neglecting actual gear tooth shape. For more accurate determination, finite element method (FEM) can be used. The actual stresses predicted by FEM are much higher than the analytical approach, so that the design of the gear shaped die is beyond the capability of the analytical approach. In this paper, analytical approach for dies with gear teeth is modified using FEM solution sets. FEM analyses results are verified by experiments. During experiments cylinder approach is observed to be inadequate for forging loads. An easy to use set of formula and nomograms for determination of sizes of die and ring, and radial interference are presented. The solution set is verified with experiments. Proposed equations can safely be used for shrink fit design of precision forging gear dies.     

Analysis of the influence of gear dimensions on cutting speed and contact conditions during the gear honing process

In many cases, gear honing represents a cost-efficient process for gear manufacturers. Another advantage of gear honing is the generation of a surface structure on the tooth flank which improves the noise behavior of the gear. Previous research activities have resulted in reliable gear honing processes, particularly for automotive gears with a tip diameter of up to 150 mm. Problems occur, however, when honing larger gears with a tip diameter of more than 150 mm, thereby rendering a robust manufacturing process is difficult. In the course of this paper, an analysis will be carried out of the geometrical and kinematic conditions that will lead to a better understanding of the process. The aim of this report is to provide an overview of the current basic conditions of the gear honing process. Theoretical studies are conducted to identify differences in gear honing processes with various tip diameters. This analysis forms the basis for optimizing process design, with the aim of generating a cost-efficient gear honing operation for gears with a tip diameter of more than 150 mm.