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目前我国生产的普通电火花机床,一般只能作垂直方向的加工。因此在用垂直进给电火花加工两开模(哈夫模)、四开模时,合摸线不易找正,合模质量无法保证。而两开模约占型腔模具总数的三分之一。型腔侧壁有花纹的模具用电火花加工时,也受到一定的局限,使不少模具无法用电火花加工。 相似文献
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塑料压模是将酚醛塑料粉或玻璃纤维经称量后直接放入模具型腔,而后将模具闭合,在平板硫化机中加压加热,使酚醛塑料粉或玻璃纤维在加热和压力作用下充满模具并固化成型的模具。其关键零件被称作哈夫模芯的模具零件,一般是两瓣对称的锥体零件。下面以典型的线圈架塑料压模为例进行分析。 相似文献
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轴承毛坯锻造质量的好坏,与切料质量有关;而切料质量又与模具结构、切料方式、加热温度和棒料与料模之间的间隙等因素有关。 一般轴承锻造厂使用的切料模,下模多为套筒式,上 相似文献
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轴承保持架“工”字型冲孔凹模以及筐型冲孔凹模的模腔加工,过去一直采用传统的钳工开模子方法,工效低,模具质量不高,寿命短。采用新工艺和新装备(用一台斜度线架装置取代原来固定式线架,同时以一台Z80微机控制台与之配合,使其具备了斜度线切割功能)后,生产效率、模具质量和使用寿命都有较大的提高。文中对斜度线架装置的结构原理作了较详细的论述。附图4幅,表1个。 相似文献
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渗碳钢轴承套圈压力淬火工艺具有工艺流程短,生产效率高,以及淬火质量好等优点。对于该工艺的若干关键技术,如活动淬火模具结构,“模限”规律和压床调整等作了较详细的介绍。 相似文献
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分析了轿车车门变截面橡胶密封条的结构特点及成型工艺,详细介绍了注料式橡胶密封条接头模结构设计,重点阐述了分型面设计、模具型芯设计及其他结构细节上的设计,为类似密封条接头模设计提供了参考。 相似文献
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针对全塑料鼠标的注塑模设计,对零件结构进行了工艺分析。确定了分型面、浇注系统等,选择了注射机,计算了成型零部件的尺寸。采用点浇口,利用直导柱导向及推杆顶料方式,对模具的材料进行了选择。如此设计出的结构可确保模具工作运用可靠。 相似文献
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To develop the hydraulic mold oscillator in continuous casting machine, the guiding mechanism of mold was studied. The main
topics of this study were to design the guiding mechanism of mold which oscillates to prevent the sticking and to reduce the
friction resistant force between the solidified shell and mold on casting. We studied many guiding types to analyze the features
of worldwide mold oscillator and developed the new model of hydraulic mold oscillator. On the basis of the mold oscillating
experiment, the capability of guiding system was proofed by the position error measuring system. The experiment was carried
out up to 50–500 cpm frequencies and 2–10 mm stroke in the variable waveform and the casting results was analyzed by the oscillation
mark of slab surface which was formed unavoidably by oscillation. 相似文献
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文中针对铁路货车轴承压装设备进行分析,提出通用轴承压装机设计方案。压装机能实现60t/70t货车轴承的自动化压装控制和压装压力检测,准确得到所需的各种参数及压装力曲线。 相似文献
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The friction force developed in the demolding phase of the micro injection molding process is mainly determined by mold surface finish, which affects the tribological phenomena occurring at the polymer–tool interface. In this work, the effects on the ejection force of two cavity surfaces machined with different technologies (viz. micro milling and micro electro discharge machining), but with similar value of Ra, were investigated. The relations between different surface topography parameters and the ejection force were then analyzed, in order to identify the parameters that most appropriately describe the friction at the polymer–tool interface. The experimental results showed the strong interactions between the mold surface texture and the micro injection molding process parameters that promote the replication, such as mold temperature and holding pressure. The different machining technologies generated two mold textures that have a similar value of Ra, but their influence on friction can be properly described only using several other surface topography parameters. 相似文献
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许善新 《机械制造与自动化》2012,41(4):56-58
在深入剖析压铸机液压-肘杆式合模机构特点的基础上,提出采用液压-螺旋机构实现压铸机的合模、锁模和开模.在压铸机的后板上由液压马达经齿轮传动装置带动螺母转动,螺母中的螺杆直线移动,驱动中板作在一定长度范围内根据实际需要而变动的合模移动,合模后依靠螺旋机构自锁性能锁模,锁模力可精确控制;同时,还设计了双液压马达驱动系统,实现快速合模和开模以及低速大扭矩锁模;为了解决动模板移动时过约束的问题,提出了中板具有局部移动自由度的机械结构方案.这三个创新点大大简化了压铸机的整体结构,提高了压铸工作效率,避免了以前因锁模力控制不当引起的种种失效,如大杠拉断、头板与中板变形和断裂等.取消了以前换模具后或零部件温度变化后必须调整后板位置的烦琐工艺,简化了控制系统.本设计方案已申请专利,并在本公司的小型压铸机上试验成功. 相似文献
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分别介绍了依据圆柱体母线对板类及轴销类零件进行定位的两种钻模。这两种钻模均以偏心轮为直接夹紧元件,在夹紧过程中,同时利用偏心轮的正压力及摩擦力使工件在互相垂直的二个方向上均能获得可靠定位。由于定位支承元件和夹紧元件均为圆柱形体及其组合,使这两种钻模不仅结构上极为简约,且制造工艺性好。 相似文献
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On the instantaneous and average piston friction of swash plate type hydraulic axial piston machines 总被引:2,自引:0,他引:2
Piston friction is one of the important but complicated sources of energy loss of a hydraulic axial piston machine. In this
paper, two formulas are derived for estimating instantaneous piston friction force and average piston friction moment loss.
The derived formula can be applicable for piston guides with or without bushing as well as for axial piston machines of motoring
and pumping operations. Through the formula derivation, a typical curve shape of friction force found from several experimental
measurements during one revolution of a machine is clearly explained in this paper that it is mainly due to the equivalent
friction coefficient dependent on its angular position. Stribeck curve effect can easily be incorporated into the formula
by replacing outer and inner friction coefficients at both edges of a piston with the coefficient given by Manring (1999)
considering mixed/boundary lubrication effects. Novel feature of the derived formula is that it is represented only by physical
dimensions of a machine, hence it allows to estimate the piston friction force and loss moment of a machine without hardworking
experimental test. 相似文献
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改进推移控制回路是提高液压支架移架速度的主要措施之一。传统的推移控制回路无法满足实际工况中移架力应大于推溜力的要求 ,而目前普遍采用的浮动活塞式推移系统尽管解决了上述问题但仍存在很多不足之处。采用逻辑式差动阀控制回路 ,不但解决了上述问题 ,而且优于其它改进方法 ,获得了良好的效果 ,并在实践中得以验证 相似文献