90°外圆弧通用切角模

<正> 在冲压生产中,经常有大量的经剪板下料的矩形板需要去除90°尖角,用手工去除费时、费力、工效很低。这就需要根据所下板料的大小,采用通用的切角模将板料的尖角切成不同大小的90°外圆弧。为此我们设     

具有弓形刀片的摆动剪板机

如果被剪板料的抗拉强度相当高而需要较大的剪切力时,必须使用适应于这一剪切力的大型机器来剪切。剪切板料开始时产生的较大抗力被剪板机床身承受而产生弹性变形。当板料被剪断时,床身又象弹簧一样恢复原状,从而使机器产生强烈的振动和相当大的噪声。为了减少这些毛病,通常采用倾斜安装的刀片,使剪切过程渐进,但容易使被剪下的板料产生     

剪板机剪切力与剪板断面形貌的关系浅析

通过观察剪板机剪板的断面形貌,分析剪板机的剪板过程,进而导出了一种剪切力的简易计算方法,该法计算结果与常用公式的计算结果近似,但方法更为简单,可作为设计计算的参考.     

QC11Y──16×2500剪板机可与国际先进产品媲美

ＱＣ１１Ｙ──１６×２５００剪板机可与国际先进产品媲美９月２５日，由江都机床总厂自行研制的ＱＣｌｌＹ—１６Ｘ２５００闸式剪板机在江都通过由机械工业部主持的部级鉴定，达到八十年代末国际同类产品先进水平。该机最大可剪板厚１６ｍｍ，最大可剪板宽２５００ｍｍ...     

QZ12K－6×3200型数控液压摆式剪板机

ＱＺ１２Ｋ－６×３２００型数控液压摆式剪板机ＱＺ１２Ｋ－６×３２００型数控液压摆式剪板机于１９９６年３月在浙江试制成功。该机可剪板厚６ｍｍ，可剪板宽３２００ｍｍ，数控轴数为１轴，后挡料最大距离６００ｍｍ，后挡料调节最大速度６ｍ／ｍｉｎ，后挡料调节定位...     

非均匀压边力板料粘性介质拉深成形的试验研究

本文提出非均匀压边力板料粘性介质拉深成形方法,这种方法采用一种介于液—固态之间的粘性介质作为凸模传力介质,通过控制板料局部压边力的不同,使板料可控制地流入凹模口,板料成形具有顺序性。给出了拉深件几何形状和厚度分布,试验结果表明：板料厚度的变化受板料流入凹模深度的影响,采用顺序成形可减小因深度的加大而引起的板料变薄     

双层摆梁的剪板机

法国普洛梅坎(Promecan)公司生产了一种新型的机械传动剪板机(图1)。其主要技术规格:被剪板厚×被剪板宽为4×3100毫米(剪切中碳钢或不锈钢板时为2.5×3100毫米),每分钟行程次数为90。当被剪板宽大于2米时,后挡料架的挡料长度为750毫米,而被剪板宽等于或小于2米时则剪切长度不受限制。机器的主要特点有:(1)采用双层摆梁结构,外梁作为压料梁,内梁作为刀架。内梁支承在外梁两侧臂上,由于内梁和外梁的摆动轴线离下刀刃的距离成一定的比例,因此在剪切过程中压料力始终与剪切力成一定的比例;     

拉深模激光毛化区域的研究

针对拉深件容易产生的起皱和拉裂缺陷进行分析,为提高板料的抗破裂性,讨论了利用激光毛化技术控制金属的流动,提高板料拉深成形性能.通过不同毛化区域对板料抗破裂性和模具使用寿命的影响进行分析,结合激光毛化表面摩擦磨损性能的试验研究,提出了拉深模激光毛化区域;同时,拉深模应对凸模进行毛化,以提高板料的拉深成形性能;若对凹模进行毛化,虽可提高模具使用寿命,但会降低板料的拉深成形性能.试验结果表明,对凸模进行毛化可增加拉深件危险断面的厚度,提高板料的拉深成形性能.     

研究单位夺边力值对板料成形性能的影响

主要介绍板料在拉深成形过程中单位压边力值对板料成形性能的影响。研究方法采用仿真技术,指出板料在成形过程中如按最初设定的单位压边力值进行成形,那么,板料成形过程中单位压边力值将逐渐增大,严重影响板料成形极限。如果采用控制板料在成形过程中压边圈下坯料的单位压边力值,将提高板料成形极限。其结论为生产现场提高板料成形性能和表面质量提供了一种可实施的方法。     

板料毛坯尺寸的优化及其CAD系统

设计的动态递归剪切新算法,实现了同尺寸矩形毛坯最优排样,当板料与毛坯尺寸相差较小时,较有优势。由此算法构成的最优排样CAD系统,可完成最优排样图形输出、板料的优选、板料按尺订货等分析。     

Investigation into thermal characteristics of linear hotwire cutting system for variable lamination manufacturing (VLM) process by using expandable polystyrene foam

The dimensional accuracy and efficiency of VLM-S, which is a new rapid prototyping process using hotwire cutter and expandable polystyrene (EPS) foam sheet, depends significantly on the thermal fields of EPS foam sheet when the hotwire cuts the sheet. The objective of this study is to investigate thermal effects of the hotwire cutting on the sheets and to find relationships between process parameters in order to obtain optimal conditions for hotwire cutting and improve dimensional accuracy of the process. Several experiments were performed to find the relationships between maximum cutting speed and heat input, and between cutting offset and heat input. Numerical analyses were carried out to investigate the influence of the cutting parameters on temperature distribution around the hotwire and to estimate the amount of the sheet melted away. Moreover, the size of the thermal front as the hotwire is about to lose its stiffness was predicted to propose the optimal cutting conditions. Based on the results, the optimal cutting conditions of the hotwire cutting system for cutting of an EPS foam sheet were found. In addition, the outcomes of the present study were reflected on the fabrication of a spanner shape and a clover punch shape.     

磁性辊轮驱动装置在切割生产线中的应用

随着汽车及机床行业的发展,板料涂油工艺在汽车零部件生产中应用广泛,从而导致板料在自动切割生产过程中极易打滑跑偏,无法保证传输精度,本文所阐述的磁性辊轮驱动装置从根本上有效解决了此问题,在切割生产线中有广泛的推广价值。     

Monitoring laser cut quality using acoustic emission

The paper presents results of an analysis of acoustic-emission (AE) signals obtained during laser cutting of a steel plates, which are frequently used in the production of automotive body components. In the course of laser cutting, continuous signals, which are related to the quality achieved of the laser cut, are measured. After laser cutting characteristic AE bursts in the specimen material, which are results of a thermal influence, can be detected. The presence of dross is an important indicator of poor quality of laser cutting. The investigation on laser cutting was conducted on an unalloyed steel DC04 sheet and on austenitic stainless steel X5CrNi18-10 sheet of 1.5 mm in thickness. The same physical mechanism in the cut formation at both steels, however, resulted in a considerable different cut quality, which was indicated by the AE signals captured after the cutting process.     

Improved corrosion protection of the cut edge of coil coated sheet

Coil coating is a process to apply organic coatings to sheet metal directly after the rolling process and before any further subsequent processing. Coil coated sheet metal has found a broad variety of applications in certain areas of the sheet metal industry, e.g. for household article casings or façade planking of buildings. However, the use of these materials is limited for a large extent of applications by its liability to corrosion of the bare cut edge which is not covered and thereby not protected by paint. A possible approach to this problem is to develop a procedure that can improve corrosion protection by the cutting process. By letting some of the surface coating flow into the cutting clearance and cover the bare cut edge, corrosion resistance can be enhanced. A different approach is to apply a corrosion inhibiting medium, e.g. UV-curing lacquer, onto the cut edge corrosion resistance can be significantly improved. To minimize process steps, this application can be integrated into the cutting process.     

Oscillation overlaid shearing of sheet

One of the most frequently used sheet metal processing methods is shearing. While using the shearing method a cut edge is usually created which often clearly fails to meet the desired quality. The optimum cut edge quality is as rectangular and as burr-free as possible. Trials made at the IFUM showed, that the quality of cut edges can be improved by overlaying the movement of the punch with an oscillation. Through different test rows the mechanism and impact of oscillation on the shearing process are investigated. This paper reports about tensile and friction tests made on sheet metal with oscillation overlay, high speed cutting tests and test series with a new designed tool which allows stamping sheet metal also with an oscillation overlay. The test series show, that oscillation can have an effect on the tensile strength, friction and work hardening of sheet metal and as a result on the cutting force and the cut edge quality.     

Development of a new sheet deposition type rapid prototyping system

Sheet deposition type rapid prototyping systems have many advantages: high build speed, low operating cost, large part size, no phase change, no need for support generation, etc. However, those sheet deposition type rapid prototyping systems generally require an additional post-processing step to remove excessive material. This post-processing step is generally time-consuming and labor-intensive as well. Especially, in case of parts with hollow cores and internal cavities, the removal of excessive materials can be an extremely demanding task.A new sheet deposition type rapid prototyping system that can minimize the post-processing is proposed. In the proposed system, the sheet is cut in two steps: the first before the shielding paper is peeled off and the second after peeling-off. The excessive area is removed during the peeling-off process after the first cutting. In this way, this system can reduce the post-processing time and cost as well as the limitation on the feasible geometric shapes compared to the conventional sheet deposition type systems.     

基于加工模拟技术的钣金切割成本估算模型研究

通过直接提取制件图形中的加工信息,基于加工知识库和加工模拟技术去估算加工工时,兼顾计算的科学性和制造工艺的不确定性,快速、合理估算钣金切割的制造成本.这一研究成果可作为生产成本的管理与市场报价的基础.     

实时功率控制在激光切割机的应用研究

利用光纤激光切割机进行板材切割的时候拐角处常有过烧的现象,这是由于激光切割尖角时,长时间加热带来热量积聚所造成的,为克服该缺点,本系统基于速度控制的激光功率控制,可有效降低烧角现象.实现结果表明该方法可以有效的提高零件的切割质量.     

Scaling laws for the laser-oxygen cutting of thick-sheet mild steel

The laws of scaling the laser-oxygen cutting of mild steel based on experimental optimization are proposed. The sheets from 5 to 25 mm are cut with the aid of CO₂ laser.It has been established that the minimal surface roughness is reached within the whole thickness range if the laser energy value per unit of the removed material and the power per sheet thickness unit are held constant. The results permit to determine the laser power and cutting speed values optimal for a certain sheet thickness. Within the range of large thicknesses, the conditions of cutting with minimal roughness are written as ratios between dimensionless variables. Evaluation of the maximum thickness of the sheet, at which the high-quality cutting is realizable, has been made.     

Influence of a defined pre-load on the stress state in the precision cutting process

Precision cutting is a single stroke shear cutting process to achieve a flush-cut amount between 60 and 90% of the sheet thickness by using a single-acting standard press. This paper presents a method to quantify the amount of required compression stresses based on theoretical and experimental precision cutting tests in which the stress state is overlaid by an additional radial pre-load on the strip. It was found that even a minimal pre-load of 30% of the yield stress can move the stress level to a state with lower tensile stress.