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【目的】以实验为基础,研究实木地板榫槽铣削加工中切削参数对切削力的影响,为不同切削工艺下加工参数的优化以及设置提供参考依据,达到提高加工质量、延长刀具寿命并用以指导生产的目的。【方法】以山毛榉材地板为试验材料,运用木材切削机理对切削速度、进给速度及切削宽度3个参数进行单因素试验,并采集切削过程中随着切削参数变化产生的切削力值,揭示在顺铣和逆铣方式下不同切削参数对实木地板榫槽铣削力的影响规律。【结果】在不同铣削方式下,随着切削速度的增大,XYZ方向的切削力总体呈降低趋势;随着进给速度和切削宽度的增大呈现升高的趋势,顺铣加工时XYZ 3个方向的铣削力变化相比逆铣加工的波动趋势小,稳定性要好。通过对铣削力回归模型进行方差分析,可知R2(Fdown)=0.9490,R2(Fup)=0.8516,均接近1,回归效果显著,验证了铣削力模型的合理性。【结论】通过对比相同切削参数在不同工艺条件下产生的切削力变化,可知顺铣加工稳定性高于逆铣加工。 相似文献
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Evgenii Sharapov Christian Brischke Holger Militz Elena Smirnova 《Wood material science & engineering》2020,15(4):198-204
ABSTRACT An IML-RESI PD 400 drilling tool and a standard spade drill bit (IML System GmbH, Wiesloch, Germany) were used to study the combined effect of wood moisture content (MC), drill bit rotational speed and feed rate on drilling resistance (DR) and feeding force (FF). Tests were made with Norway spruce (Picea abies (L.) Karst.) conditioned in a normal climate (20°C/65% RH), at 20°C/95% RH, vacuum-pressure impregnated in water, and oven-dried. Rotational speeds and feed rates had an impact on feed rate per cutting edge for the major cutting edge of the drill bit which was used for correlation with DR and FF for various MC. Impact of MC on DR and FF depended on rotational speeds and feed rates of the drill bit. For feed rates per cutting edge less than 0.09?mm, DR was higher for water saturated (WS) specimens. Negligible differences between DR for various MC were found for feed rates per cutting edge between 0.09 and 0.15?mm. DR was higher at low MC for feed rates per cutting edge which were higher than 0.15?mm. FF extremely increased in conditioned (20°C/95% RH) and WS specimens at feed rates per cutting edge less than 0.1?mm. 相似文献
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介绍几种表面涂层木工刀具的加工方法和使用状况,分析表面涂层刀具的切削特点和磨损形态,概述了国内外研究进展.研究成果表明,涂层处理可以延长刀具使用寿命,减少刃磨和换刀时间,提高生产效率和表面加工质量. 相似文献
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The measurement of wood surface roughness is performed once the machining process is completed. It requires considerable time since the measurement is performed at slow speed. The objective of this study was to develop a method to evaluate the surface roughness of paper birch wood while routing. For this purpose, a number of transducers were mounted on the router spindle and also in the proximity of the workpiece and cutting zone. Signals were acquired during a wide range of cutting conditions and analyzed. Statistical regression and artificial neural networks were employed to establish relationships between the signals and the actual cutting depth and surface roughness. The sensor selection and the feasibility of the sensor placement were determined. The models were subjected to a validation procedure to confirm their performance. The placement of the microphone at constant distance from the cutting zone was determined to be the most useful one. A model able to predict the surface roughness of routed paper birch wood regardless of the depth of cut was produced. The performance of the model was valid independently of the length of the workpiece. 相似文献
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The experimental results of orthogonal cutting of maple and the modeling of the cutting mechanics are presented. The tool cutting forces were measured for different feed rates. A set of equations relating the tangential and feed forces to the tool edge width and feed rate (chip thickness) to calculate the chip and edge cutting force coefficients was developed. Then the chip force and edge force coefficients were calculated from experimentally obtained cutting forces and were plotted in a polar-coordinate system with respect to the fiber orientation of the maple disk. The polar-coordinate presentation of the cutting force results and the calculated cutting force coefficients provides an excellent visual appreciation of the relation between the cutting forces and the wood fiber orientation. Chips were also collected from various sectors of the wood disk. This analysis further identified the effects of fiber orientation and cutting forces on the types of chip formed and hence the cutting mechanics involved. By applying the calculated cutting coefficients for each tool orientation (in respect to the grain) it is possible to predict the feed and tangential forces for any feed rates. There is good agreement between the predicted and measured cutting forces. 相似文献
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《Wood material science & engineering》2013,8(3):185-190
ABSTRACTThe aim of this paper is to study the effect of high moisture content in comparison to dry timber on the resulting cutting forces based on experimental small-scale chipping tests. Therefore, a wood chipper for single cuts is designed and different species of Austrian locally growing trees are utilized. The test specimens are investigated in almost dry and soaked wet conditions. The resistance of wood is measured utilizing a force sensor and the signal during the cutting process is subsequently analysed by two different methods. The results reveal that the mean value of the acting force during cutting is 38–81% minor compared to the maximum force. Even though the peak of the dynamically acting load is measured for just a comparably small time range, it reveals an impact on the fatigue behaviour of the tool as well as the tool supporting material. Hence, an approach of evaluated load spectra is applied to include the load distribution of the chipping process. The effect of dry and wet wood on the cutting resistance is examined, whereby wood exhibiting a high moisture content of 30–40% changes the acting load up to 98%, depending on the method of analysis. 相似文献
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通过对超细木粉的形态分析,提出了超细木粉颗粒的粒径范围为600~1 500目;介绍了超细木粉加工设备的结构与原理,分析了制备超细木粉的粉碎过程及粉碎力,以及超细木粉的制备方法及所采用的设备对粉体产品的粒度大小、粉体形状及分散性等的影响。提出采用高速旋转搅拌式磨削粉碎方法,将粉碎设备与粉体分级设备连为一体,对未达到加工目数要求的颗粒进行循环式加工,提高了加工效率;在分级装置的不同位置安放两个转速不同的离心风机形成不规则的气流流场,能减少木粉收集时的颗粒团聚,提高了粒度分布的均匀性和木粉质量。 相似文献
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Jiri Pyörälä Ville Kankare Mikko Vastaranta Juha Rikala Markus Holopainen Marketta Sipi 《Scandinavian Journal of Forest Research》2018,33(3):291-298
While X-ray scanning is increasingly used to measure the interior quality of logs, terrestrial laser scanning (TLS) could be used to collect information on external tree characteristics. As branches are one key indicator of wood quality, we compared TLS and X-ray scanning data in deriving whorl locations and each whorl’s maximum branch and knot diameters for 162 Scots pine (Pinus sylvestris L.) log sections. The mean number of identified whorls per tree was 37.25 and 22.93 using X-ray and TLS data, respectively. The lowest TLS-derived whorl in each sample tree was an average 5.56?m higher than that of the X-ray data. Whorl-to-whorl mean distances and the means of the maximum branch and knot diameters in a whorl measured for each sample tree using TLS and X-ray data had mean differences of ?0.12?m and ?6.5?mm, respectively. One of the most utilized wood quality indicators, tree-specific maximum knot diameter measured by X-ray, had no statistically significant difference to the tree-specific maximum branch diameter measured from the TLS point cloud. It appears challenging to directly derive comparative branch structure information using TLS and X-ray. However, some features that are extractable from TLS point clouds are potential wood quality indicators. 相似文献
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The general aim of work reported here was to assist designers and operators of routers and similar tools for cutting wood-composite
boards, by providing a model predicting cutting force components from readily available material properties. This initial
study explored, for edge cutting, the variation within a single medium density fibre board across the thickness and in various
cutting directions in the plane of the board. Material properties of interest were specific gravity and friction coefficient.
In slow linear cutting on a modified milling machine, carbide router inserts cut the edges of layers cut from a medium density
fibre board. Specific gravity and coefficient of sliding friction were measured for each layer. Cuts were also made on full-thickness
edges in various directions in the plane of the board. Chip thickness was varied from 0.025 to 0.8 mm. Parallel and normal
force data and digital video images of chip formation were stored for analysis. Specific gravity increased as the fourth power
of the distance from the central plane to the surface. Friction coefficient values, estimated both from cutting forces and
from rubbing forces during return, varied about a value of 0.23, with no significant difference between layers. The values
for cutting force per mm width of cut increased progressively from the central plane to the surface, in a logarithmic relation
with specific gravity. The cutting forces did not vary with cutting direction in the plane of the board. For a sharp edge
with 32° rake angle cutting at chip thickness values above 0.1 mm, the normal force component was negative, indicating reduced
feed force and improved surface quality. With dulling, the threshold value of chip thickness for this increased. It is concluded
that elaboration of this approach would generate relationships suitable for incorporating in a useful general model. However,
it may be found that weight per unit area of board will suffice as a proxy for cutting resistance in modelling the cutting
of full-thickness edges.
Received 10 June 1999 相似文献
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微米长薄片木纤维切削加工功率的理论计算方法与效益分析 总被引:8,自引:2,他引:6
对传统纤维加工的功耗进行分析,将细胞学、超精加工理论、纤维学等一系列现代分析手段运用到木纤维的形成过程中,提出微米长薄片木纤维切削的概念,从而将微米长薄片木纤维的研究上升到微观结构,并通过对纤维形状的产生和切削力变化的分析,解释传统木纤维加工消耗的能源高、产生纤维质量差的本质原因.示例对微米长薄片木纤维的加工功率进行计算,将其与传统加工方法的功率进行对比,得出结论:以微米级机械法加工木纤维耗能远远低于热磨法,且可以加工出质量较高的微米级长丝木纤维. 相似文献
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This paper studies the problem of high energy waste in the course of the wood fiber processing in the wood-based panel industry.
In the light of the energy economy principle, the cutting theory on the micron and long-slice wood fiber was put forward.
In this paper, by means of analyzing the power waste in traditional processing, a series of analytical measures, such as,
cytology, super precision work theory and fiber processing, and so on were utilized in the micron wood fiber formation process,
and the cutting conception of the micron and long-slice wood fiber was put forward. Accordingly, the study of the micron and
long-slice wood fiber was put into the microstructure study. This paper scientifically explains the reasons why the traditional
wood fiber processing consumes more energy and the fiber quality low. In an example, the cutting power on the micron and long-slice
wood fiber was calculated, which was compared with the traditional cutting power. The result showed that the energy waste
by machining at micron is much lower than by heat grind and the high quality and long-slice wood fiber was gained. Thus, a
revolutionary step was taken in the paper-making and wood-based panel industry of China.
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Translated from Scientia Silvae Sinicae, 2006, 42(3): 44–46 [译自: 林业科学 2006, 42(3): 44–46] 相似文献
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作为一种主动无损检测方式, 声发射技术通过分析被测物体内部因能量变化所引发的弹性波的特征, 判断物体内部损伤程度并确定损伤位置。声发射技术为木材加工过程应力监测提供了一种主动无损检测模式, 但受木材自身各向异性等特点的限制, 目前声发射技术在木材工业中的应用尚处于探索阶段。为此, 文中重点介绍了目前声发射技术在木材切削加工、木材及木质结构、木材力学性能、木材干燥过程等木材加工过程的应用现状, 并在此基础上根据木材声发射信号特点, 提出一种基于LabView及高速采集设备的木材干燥过程声发射监测系统设计方案。 相似文献