含水率对木质材料切削力影响的研究

采用硬质合金锯齿刀具分别对三种实木(杉木、樟子松、水曲柳)和两种人造板(中密度纤维板、刨花板)进行闭式切削实验,研究不同含水率对木质材料切削力的影响。实验结果表明:含水率对木质材料切削力的影响显著。随着含水率的增加,杉木的主切削力和法向力都呈减小趋势,而樟子松和水曲柳的主切削力皆为先增大后减小,当接近纤维饱和点含水率时主切削力达到最大。对人造板,在5%～18%含水率范围内,随着含水率的增加,主切削力和法向力都不断增大。     

切削参数对竹材切削力影响的研究

研究了竹材切削不同刀具前角、切削量与切削速度对切削力的影响.刀具前角对主切削力的影响较为显著,随刀具前角的增大,所需主切削力明显减小.主切削力与切削量成正相关关系.切削速度对切削力的影响不大.     

基于ABAQUS的高温合金GH4169切削力仿真研究

为了研究镍基高温合金加工中切削用量对切削力的影响,课题组借助高温合金的材料本构模型、失效准则、切削过程中的切屑分离准则和摩擦模型,利用ABAQUS有限元分析软件建立了镍基高温合金的二维切削仿真模型,分别以切削速度、切削深度和进给量为单一变量,探究切削力的变化规律。结果表明:切削力随切削速度的增加而减小,并趋于稳定状态;切削力随着进给量和切削深度的增大而增大;相较于切削速度,进给量和切削深度对切削力的影响更大。     

椭圆活塞切削力的影响因素研究

文章对不同刀具前角、不同切削速度、不同切削深度、不同刀具刃口钝圆半径以及不同频率对工件应力应变及切削力的影响进行了仿真研究,分析了在不同参数影响下主切削力和背吃刀力的变化情况。     

木材切削原理与刀具 三

2.5切削力与切削功率2.5.1切削力的分量 象任何力一样,切削力也可以分解。通常将切削力沿垂直于木材平面和平行于木材平面两个方向分解,也就是沿刀刃与木材相对运动的方向分解,垂直于切削速度方向的分力,称为法向力,平行于切削速度方向的分力,称为主切削力F_c,大多数情况下法向力是压向木材表面称为压力(“ ”),有时法向力将木材拉离加工表面,称为拉力(“-”)。     

竹材物理性质对切削力影响的研究

经切削实验研究了竹材不同切面、密度与含水率对切削力的影响。结果表明:竹黄部位微管束分布较疏,所需主切削力较小,竹青部位微管束分布密集,主切削力较大;端面切削主切削力最大,纵向切削次之,横向切削最小;竹材密度对切削力有明显影响,且呈正相关关系;随着含水率的增加,竹材韧性增大,所需主切削力增加。当含水率超过33.6%之后,随含水率的进一步增加,竹材软化作用明显,主切削力缓慢下降。     

微织构超硬刀具切削粉末冶金的切削力研究

文章主要研究微织构超硬PCBN刀具车削粉末冶金材料时,切削速度和织构参数对切削力的影响,通过四因素四水平的正交试验,得到了在润滑条件下,切削速度v、凹坑直径d、凹坑深度h和面积密度w四个参数对三个切削分力和切削合力的影响关系,d和h对切削力的影响更大,微织构的引入对进给抗力F_X和切深抗力F_Y的影响大于主切削力F_Z,得到了织构参数对切削力的影响关系,对微织构超硬PCBN刀具切削粉末冶金材料的织构设计具有一定参考意义。     

PcBN刀具硬态干切削条件对切屑形貌的影响

通过对PcBN刀具硬态干切削GCr15轴承钢的试验研究,观察分析研究了不同切削条件对切屑形貌的影响。结果表明,随着切削速度的增加,切屑锯齿化程度也越高,当切削速度大于200m/min时,切屑类似于挤裂状;随着进给量的增加,切屑的锯齿化程度越来越明显,且在进给量达到0.5mm/r时,切削产生严重变形;随着背吃刀量的增加,切屑的卷曲程度越大,但对锯齿化影响并不大,但当背吃刀量为0.05mm时,切削基本呈带状。     

不同密度和厚度对蓖麻秆刨花板性能的影响研究

在蓖麻秆刨花板最佳工艺条件下,研究了不同厚度和密度对板材性能的影响,结果表明,当板材的厚度为10mm时,板材的各项性能随板材密度的增加而增大,当板材的密度大于0.64g/cm3时,板材的各项性能除吸水厚度膨胀率以外,其余各项性能均可满足国家普通刨花板标准对室内装饰和家具用材的要求。在设定板材密度一定的情况下,板材性能随厚度的增加而先增加后减小。     

椭圆振动车削TC4的切屑形态和切削力研究

为探究超声椭圆振动车削钛合金TC4过程中振幅、频率和刀尖圆角半径对切屑和切削力的影响,课题组通过建立有限元模型,将常规切削(CC)和椭圆振动切削(EVC)钛合金TC4过程进行对比研究。首先对所用超声椭圆振动的运动特性进行推导,确定刀屑接触率;其次通过理论分析,将切屑和切削力相结合,建立切削力模型;最后分别研究不同频率、振幅对超声椭圆振动切削稳定过程时的切屑形态、切削力和切削温度的影响。研究结果表明:椭圆振动切削过程刀具和切屑间存在周期性地分离,可以用刀屑接触率ts表示;在一定的范围内,增加振动幅值、振动频率以及刀尖圆角半径可以减小切屑厚度,降低切削力; EVC方式下可以选择合理的参数来降低切削力,并可以通过测量宏观切屑厚度来预测切削力,更好地指导生产加工。     

Effects of cutting parameters on cutting forces and surface quality of black spruce cants

The effects of rake angle, cutting direction, and depth of cut on cutting forces and surface quality of black spruce were evaluated. Cutting forces were measured during cutting at four rake angles (35°, 45°, 55° and 65°), four cutting directions (0°–90°, 15°–75°, 30°–60°, and 45°–45°), and three depths of cut (1, 2, and 3 mm). Torn grain, waviness, and roughness were evaluated. The results showed that as rake angle increased, cutting forces, torn grain, waviness, and roughness decreased. The lowest cutting forces and the best surface quality were obtained with 65° of rake angle. At this angle, cutting forces and surface quality were more affected by depth of cut than by cutting direction variations. Thus, as depth of cut decreased, the effects of cutting orientation on the cutting forces and surface quality decreased. The application of these results to the canting work of a chipper-canter is analyzed.     

Parallel and normal cutting forces in peripheral milling of wood

In this paper, the parallel and normal cutting forces on the tip of the tool are examined when altering a number of parameters in peripheral milling. The parameters studied are rake angle, chip thickness and upward/downward milling. The evaluation of the forces has been performed during cutting of the chip and the variation in the forces has been recorded. In this way, important information can be obtained in order to arrive at cutting data and tool geometries that will reduce surface defects such as torn and raised grain. In the past, very few investigations have been carried out on peripheral milling, probably because of the difficulties of measurement. Nowadays, however, new measuring techniques and equipment make it possible to measure cutting forces even in standard milling machines. In this work, a sensor was placed under the workpiece to measure the forces in three directions at frequencies up to 7000 Hz. To obtain detailed data, a plastic material was used so that the cutting (revolution) speed could be kept at a minimum, thereby maximizing the number of readouts per incision. The results show how the normal force (the force component perpendicular to the workpiece) varies during the cut and how it is dependent on the examined parameters. This force changes from negative to positive during the cut. When altering the machining parameters, the normal force changes in both direction and magnitude. The other force component, the parallel force, also shows a dependence on the parameters. The objective of this research is to find parameters that minimize the normal forces in order to avoid damage to the wood.     

Microbevel for cemented tungsten carbide wood cutting tools

The microbevel method for increasing the rake angle of carbide tools was investigated. Relationship between the microbevel width, angle and the fracture of the cutting edge was established for cutting dry western hemlock knots. Also wear rate of microbevelled tool was investigated. Relatively small microbevel widths at a 30° bevel angle completely prevented edge and corner breakage of carbide tools with rake angles up to 50. Unbevelled carbide tools failed at rake angles larger than 30°. Tool life was not affected by the microbevel.     

沙生灌木切削特性与采伐机具的研究

对内蒙古西部地区的沙生灌木资源状况及其采伐现状进行了调查研究,对柠条材的锯切力进行了测试,分析了锯切功率,并设计了以小四轮拖拉机为动力源的沙生灌木采伐机具。     

仿生切削机切削力与切片形态的试验分析

利用电测应变法对一种仿生切削刀具不同切削角度下的切削力和切片形状进行试验研究.试验时,在下切刀的切面上粘贴箔金属应变片,通过静态标定和动态切削信号的采集与分析,测得其切削力大小,并对切削力试验和切片形态进行了分析.     

Study on the normal component force in oblique cutting of wood

Based on a series of experiments, the relationships between normal component forces and oblique angles of cutting edge, and normal rake angles in oblique cutting of wood were studied. The experiments consist both of the 90°-0° and the 0°–90° oblique cutting situation. Each type of experiment includes two wood species and two kinds of thickness. Through the experiments, the rules of the effect of oblique angles of cutting edge and normal rake angles on normal component force were found out. The calculation methods of normal component force were studied by mathematical analysis.     

金刚石复合片刀具磨损机理研究

选用平均粒度10微米的金刚石复合片制成刀具,对高硅铝合金（Al-30wt%Si）进行切削实验。通过扫描电子显微镜分析了工件的形貌以及金刚石刀具前后刀面磨损的微观形貌。其磨损程度与切削路程为线性关系,金刚石刀具的磨损主要是后刀面机械摩擦磨损以及前刀面的粘接磨损,而没有出现像立方氮化硼刀具的化学磨损以及月牙洼磨损。     

纺织用裁条机的研制

介绍了研发的纺织用裁条机设备的工作原理和结构,给出了采用的工艺参数,分析了设备的技术特点和创新点.优点是布条边缘裁切整齐,无打折、跑偏现象,裁切力均匀,减少了人工动作,且能连续进行裁切.