基于Moldflow的排水泵过滤网注塑工艺优化与模具设计

利用Moldflow对塑料排水泵过滤网的注塑成型过程进行仿真,通过对其结构分析制定了合理的浇口位置和冷却水路。利用三因素三水平正交试验,研究了熔体温度(A)、充填压力(B)和开模时间(C)对于塑件翘曲变形的影响,得出较优的工艺参数组合为A_(1)B_(3)C_(3),即熔体温度220℃,充填压力80%,开模时间6 s,此时塑件的最大翘曲变形量为0.632 8 mm,与优化前相比降低了10.37%。最后依据Moldflow的分析结果,利用UG软件对注塑模具的结构进行了设计,根据塑件卡扣的结构特点,型腔采用整体式结构,型芯设计为组合式(主型芯+滑块)结构,并采用三组“斜导柱+滑块”式侧向抽芯机构解决脱模问题。为实现顺序脱模,借助尼龙塞以增加定模板与动模板之间的开模阻力,设计了内置式“小拉杆+拉杆套”结构的定距分型机构;考虑到塑件形状和模具结构与成本,设计了沿塑件侧壁轮廓排布的圆推杆脱模机构;为避免气纹、气穴等缺陷的形成,在型腔处设计了排气槽结构。该模具结构设计较为合理,可为其他结构相似塑件的模具设计提供有益参考和指导。

A combination of digital design and three-dimensional printing to assist treatment of thoracolumbar compression fractures using percutaneous kyphoplasty

Objective:To evaluate the clinical efficacy of the preoperative digita1 design combined with three dimensional(3D)printing models to assist percutaneous kyphoplasty(PKP)treatment for thoracolumbar compression frac tures.Methods:From January 2018 to August 2020,we obtained data of 99 patients diagnosed thoracolumbar compression fractures.These patients were divided into control group(n=50)underwent traditional PKP surgery,and observation group(n=49)underwent preoperative digital design combined with 3D printing model assisted PKP treatment.The clinical efficacy was evaluated with five parameters,including operation time,number of intraoperative radiographs,visual analogue scale(VAS)score,Cobb Angle change,and high compression rate of injured vertebrae.Results:There were statistically significant differences of operation time and number of intraoperative radio graphs between the two groups(P<0.05).For VAS score,Cobb Angle change and vertebral height compression rate,all of these three parameters were significantly improved when the patients accepted surgery teatment in two groups(P<0.05).However,there were no significant differences between control group and observation group for these three parameters either before or after surgery(P>0.05).Conclusions:Through the design of preoperative surgical guide plate and the application of 3D printing model to guide the operation,the precise design of preoperative surgical puncture site and puncture Angle of the injured vertebra was realized,the number of intraoperative radiographs was reduced,the operation time was shortened and the operation efficiency was improved.

Kansei Engineering Applied to the Form Design of Injection Molding Machines

This study investigated the relationship between a subject’s evaluation of injection molding machines (IMMs) and formal design features using Kansei engineering. This investigation used 12 word pairs to evaluate the IMM configurations and employed the semantic differential method to explore the perception of 60 interviewees of 12 examples. The relationship between product feature design and corresponding words was derived by multiple regression analysis. Factor analysis reveals that the 12 examples can be categorized as two styles—advanced style and succinct style. For the advanced style, an IMM should use a rectangular form for the clamping-unit cover and a full-cover for the injection-unit. For the succinct style, the IMM configuration should use a beveled form for the safety cover and a vertical rectangular form for the clamping-unit cover. Quantitative data and suggested guidelines for the relationship between design features and interviewee evaluations are useful to product designers when formulating design strategies.

Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

The Design of a Three-Dimensional Physical Modeling System for Real-Time Groundwater Flows

In the past decades,physical modeling has been widely used in hydrogeology for teaching,studying and exhibition purposes.Most of these models are used to illustrate hydrogeological profiles,but few can depict three-dimensional groundwater flows,making it impossible to validate groundwater flows simulated by numerical methods with physical modeling.

SAR regional all-azimuth observation orbit design for target 3D reconstruction

Three-dimensional(3D) synthetic aperture radar(SAR)extends the conventional 2D images into 3D features by several acquisitions in different aspects. Compared with 3D techniques via multiple observations in elevation, e.g. SAR interferometry(InSAR) and SAR tomography(TomoSAR), holographic SAR can retrieve 3D structure by observations in azimuth. This paper focuses on designing a novel type of orbit to achieve SAR regional all-azimuth observation(AAO) for embedded targets detection and holographic 3D reconstruction. The ground tracks of the AAO orbit separate the earth surface into grids. Target in these grids can be accessed with an azimuth angle span of360°, which is similar to the flight path of airborne circular SAR(CSAR). Inspired from the successive coverage orbits of optical sensors, several optimizations are made in the proposed method to ensure favorable grazing angles, the performance of 3D reconstruction, and long-term supervision for SAR sensors. Simulation experiments show the regional AAO can be completed within five hours. In addition, a second AAO of the same area can be duplicated in two days. Finally, an airborne SAR data process result is presented to illustrate the significance of AAO in 3D reconstruction.

Structural Design and Optimization of Comb-type Electric Bicycle Three-dimensional Parking Garage

With the reduction of urban land, the three-dimensional garage is increasingly built with its advantages of saving land. But the current three-dimensional garage is built for the car. It is hardly stereo parking garage for electric bicycles. This paper designed a hollow tower electric bicycle stereo parking garage with fork comb structure, based on the analysis of the characteristics of electric bicycles and the characteristics of existing three-dimensional garages. A fixed comb is mounted on the garage frame. The movable comb is mounted on the middle lift mechanism of the garage. The access of the vehicle is achieved by the exchange of the comb. The key comb structure was modeled using SolidWorks software and the stress distribution of the structure was analyzed. It was optimized by MATLAB software. The result shows that this structure can improve access efficiency. The quality of the comb structure can be minimized under the constraints of strength requirements.

Design of an Acoustic Levitator for Three-Dimensional Manipulation of Numerous Particles

We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-air.By changing the phase difference of transducer arrays,three-dimensional manipulation of particles is successfully realized.Moreover,the relationship between the translation of particles and the phase difference is experimentally investigated,and the result is in agreement with the theoretical calculation.This design can expand the application of acoustic levitation in many fields,such as biomedicine,ultrasonic motor and new materials processing.

Three-dimensional global interconnect based on a design window

Based on a stochastic wire length distributed model, the interconnect distribution of a three-dimensional integrated circuit （3D IC） is predicted exactly. Using the results of this model, a global interconnect design window for a giga-scale system-on-chip （SOC） is established by evaluating the constraints of 1） wiring resource, 2） wiring bandwidth, and 3） wiring noise. In comparison to a two-dimensional integrated circuit （2D IC） in a 130-nm and 45-nm technology node, the design window expands for a 3D IC to improve the design reliability and system performance, further supporting 3D IC application in future integrated circuit design.

基于Moldflow优化的计算机CPU涡轮风扇模具设计

结合CPU涡轮风扇的注射成型要求,采用CAE辅助分析优化得到了塑件的成型方案为1模1腔、正面中心轴顶端进浇模腔布局,单点热嘴环形热浇口浇注。利用分层抽芯的方法将单个涡轮叶槽的脱模采用上、中、下3层滑块的顺序实施抽芯的方法进行侧抽芯脱模,从而得到整个涡轮风扇叶槽的所需脱模机构为27个滑块机构,分别为上层9个上滑块机构、中层9个中滑块机构、下层9个下滑块机构。根据滑块机构的抽芯驱动需要,将模具的整体结构采用一种假三板模结构,分3次开模,第一次开模用作下层9个滑块机构的侧抽芯驱动;第二次开模用作上层9个滑块机构的侧抽芯驱动;第三次开模用作塑件的完全脱模,第三次开模打开后,随着中层9个油缸驱动9个中滑块侧抽芯动作的完成,塑件自动脱落而实现完全脱模。结合涡轮风扇叶槽难以脱模的实践难题,设计了3层滑块机构按序抽芯,根据模具开模提供的驱动进行设计,有效地解决了涡轮风扇塑件的成型难题,机构动作可靠,生产效率较高。

Application of Digital Technology in Road and Bridge Design

With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to today’s digital software design era.Early designers relied on hand-drawn paper design forms which was time-consuming and error-prone.Digital support for road and bridge design not only saves the design time but the design quality has also achieved a qualitative leap.This paper engages in the application of digital technology in road and bridge design,to provide technical reference for China’s road and bridge engineering design units,to promote the popularity of Civil3D and other advanced design software in the field of engineering design and development,ultimately contributing to the sustainable development of China’s road and bridge engineering.

Set up the Mechanical Curriculum System Based on Three-Dimensional Design

The changes of design methods and manufacturing techniques have brought new requirements for engineers in enterprises, and therefore brought a challenge to the traditional teaching system of mechanical major courses. A new teaching system based on three-dimensional design to cultivate modern engineers with solid specialty bases and high creativity in a wide range of fields is presented.

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

Pro/MoldDesign在模具零件设计中的应用

介绍了利用Pro/MoldDesign进行模具设计的基本流程,并以手机外壳零件为例,利用现有的三维零件模型创建参照零件和工件、模型的检验(拔模和厚度检验等)、分形线/面的创建,模具体积块的创建及模拟打开过程,对建模过程中的软件操作进行了简要的分析,实现了Pro/E软件在复杂型面模具设计与制造中的应用。为利用现有实体模型设计生成模具提供了一种切实可行的模具设计方案。

基于Moldflow和UG的活动盖板数值仿真分析及模具设计

目的为了提高开模成功率,提出一种数值仿真与模具设计相结合的方法,使模具关键参数的设计具有科学依据。方法根据经验设计几种进浇方案,然后从模流分析仿真结果中选出一种较好的方案作为预选方案;对预选方案的重要参数进行验证,如缩水性、填充时间、填充等值线、流动前沿温度、熔接痕和气穴等,在验证通过后,使用三维设计软件UG进行模具设计。结果进浇方案2的翘曲变形量较小,为0.61mm,可作为预选方案。对方案2进行验证可知,产品无缩水情况,填充均匀,熔体流动前沿速度一致,没有出现流痕和虎皮纹现象,熔接痕出现在非外观表面且数量较少,气穴仅出现在产品边缘。待模具冷却系统设计完毕后进行仿真分析,结果表明,凸凹模模温温差小于10℃,产品内应力较小,无翘曲变形风险,方案2可作为最终方案。结论提出的数值仿真与模具设计相结合的方法,准确预测了产品成型质量,为模具设计提供了科学依据,极大提高了开模一次性成功率。

基于Pro／MOLDESIGN及NC的不规则破孔壳体件塑料模成型零件快速设计与制造

应用Pro／MOLDESIGN和NC模块实现了不规则破孔壳体件塑料模具成型．零件的快速设计与制造，从而缩短模具开发周期，降低开发成本。开模仿真结果验证了模具设计的合理性。

基于MoldFlow的鼠标上盖注射模设计

鼠标上盖为外观件,属薄壁壳体类塑件,注射成型质量较难控制。在结构分析的基础上,对模具进行整体设计,分析了模具工作过程,设计了斜顶机构、司筒机构,有利于实现上盖背面卡扣、柱体的脱模,设计了潜伏式浇口,避免出现浇口痕迹。并对浇注系统、推出机构及冷却系统的设计进行了分析。在设计过程中使用了MoldFlow软件对结构进行分析,对设计方案进行数据分析、对比,迅速得出优化的模具设计方案,省去了试模过程,有效地提高了模具设计效率和设计质量。

Three-dimensional(3D) Printing Technology Assisted by Minimally Invasive Surgery for Pubic Rami Fractures

The feasibility of three-dimensional (3D) printing technology cgmbined with minimally invasive surgery in the treatment of pubic rami fractures was explored.From August 2015 to October 2017,a series of 30 patients who underwent surgical stabilization of their anterior pelvic ring (all utilizing the 3D printing technology)by one surgeon at a single hospital were studied.The minimally invasive incisions were made through anterior inferior cilia spine and pubic nodule.Data collected included the operative duration,the blood loss,the damage of the important tissue,the biographic union and therecovery of the function after the operation.Measurements on inlet and outlet pelvic cardiograph were made immediately post-operation and at all follow-up clinic visits.The scores of reduction and function were measured during follow-up.Results showed that the wounds of 30 patients were healed in the first stage,and there was no injury of important structures such as blood vessels and nerves.According to the Matta criteria,excellent effectiveness was obtained in 22 cases and good in 8 cases.According to the functional evaluation criteria of Majeed,excellent effectiveness was obtained in 21 cases and good in 9 cases.It was suggested that the 3D printing technology assisted by minimally invasive surgery can better evaluate the pelvic fracture before operation,which was helpful in plate modeling, and can shorten surgery duration and reduce intraoperative blood loss and complications. The positioning accuracy was improved,and better surgical result was finally achieved.

Three-Dimensional Ocean Sensor Networks:A Survey

The past decade has seen a growing interest in ocean sensor networks because of their wide applications in marine research,oceanography,ocean monitoring,offshore exploration,and defense or homeland security.Ocean sensor networks are generally formed with various ocean sensors,autonomous underwater vehicles,surface stations,and research vessels.To make ocean sensor network applications viable,efficient communication among all devices and components is crucial.Due to the unique characteristics of underwater acoustic channels and the complex deployment environment in three dimensional(3D) ocean spaces,new efficient and reliable communication and networking protocols are needed in design of ocean sensor networks.In this paper,we aim to provide an overview of the most recent advances in network design principles for 3D ocean sensor networks,with focuses on deployment,localization,topology design,and position-based routing in 3D ocean spaces.

The Simulation and Optimization of Aspheric Plastic Lens Injection Molding

For the purpose of reducing the volumetric shrinkage and volumetric shrinkage variation, the process in injection molding of aspheric plastic lens was simulated, and several process parameters which include holding pressure, melt temperature, mold temperature, fill time, holding pressure time and cooling time were optimized by using an orthogonal experimental design method. Finally, the optimum process parameters and the influence degree of process parameters on the average volumetric shrinkage and the volumetric shrinkage variation are obtained.