scholarly journals Experimental study of the characteristics of the circular saw cutting unit linear electric drive

2021 ◽  
Author(s):  
В.И. Мелехов ◽  
И.И. Соловьев ◽  
А.В. Емельянов ◽  
Е.В. Сазанова ◽  
Т.В. Тюрикова
Keyword(s):  
Mathematical Model ◽  
Electrical Conductivity ◽  
Short Circuit ◽  
High Productivity ◽  
Wood Processing ◽  
Circular Saw ◽  
Tractive Effort ◽  
Saw Blade ◽  
Circular Saws ◽  
Cutting Unit

Широкое применение круглопильных станков в лесопильной и деревообрабатывающей промышленности обусловлено их высокой производительностью, простотой, надежностью конструкции, низкой энергоемкостью. Для повышения полезного выхода пилопродукции применяют тонкие пилы. Существенным недостатком, ограничивающим использование таких пил, является их недостаточная жесткость и устойчивость во время работы. Для повышения изгибной жесткости круглой пилы применяются щелевые, роликовые, аэростатические и электромагнитные направляющие. Большинство направляющих создают сопротивление вращению диска пилы. К недостаткам круглопильных станков следует отнести механические потери при передаче крутящего момента от двигателя диску пилы. Колебания диска круглой пилы во время работы являются еще одним недостатком тонких круглых пил, которые снижают качество обработки древесины, приводят к поломкам пил и повышенному уровню шума. Для увеличения надежности узла резания, стабилизации диска пилы во время работы, уменьшения колебаний пильного диска предложено использовать линейный асинхронный дугостаторный двигатель (ЛАДД), ротором в котором является сама круглая пила. Для проверки разработанной математической модели ЛАДД с круглой пилой в качестве ротора была создана экспериментальная установка. Целью работы явилась экспериментальная оценка математической модели и анализ рабочих и механических характеристик ЛАДД, характеристики холостого хода и короткого замыкания двигателя, зависимости мощности и cos ϕ от скольжения. Экспериментально установлено влияние электропроводности диска пилы на эффективность ЛАДД. Для увеличения тягового усилия предложено нанести на боковые поверхности диска пилы материал с высокой электропроводностью (медь). Проведенный эксперимент показал существенное увеличение тягового усилия для диска пилы с покрытием медью. Установленная экспериментально величина магнитной индукции в воздушном зазоре ЛАДД показала корректное совпадение с результатами расчетов по разработанной математической модели. The circular saws are widespread in sawmill and woodworking industry due to their high productivity, simplicity, design reliability, and low energy consumption. Thin saws are used to increase the effective yield of sawn timber. The insufficient rigidity and stability during operation of such saws limit their use. Slotted, roller, aerostatic and electromagnetic guides are applied to increase the bending stiffness of a circular saw. Most such guides create resistance to the rotation of the saw blade. Mechanical losses during the torque transmission from the motor to the saw blade is one of the circular saws disadvantages. Another disadvantage of thin circular saws is vibration of the circular saw blade during operation, which reduce the quality of wood processing, lead to the saw crashes and increased noise levels. It is proposed to use a linear induction arc-stator motor (LIASM), implementing the circular saw is the rotor, to increase the reliability of the cutting unit, stabilize the saw blade during operation, and reduce the oscillations of the saw blade. The experimental setup was created to analyze the developed mathematical model of a LIASM with a circular saw as a rotor. The aim of the work is the experimental evaluation of the mathematical model and the analysis of operating and mechanical LIASM characteristics, idling and short-circuit characteristics of the motor, the dependence of power and cos ϕ on slip. The influence of the saw blade electrical conductivity on the efficiency of the LIASM has been experimentally established. It was proposed to apply a material with high electrical conductivity (copper) on the side surfaces of the saw blade to increase the tractive effort of the drive. The carried-out experiment showed a significant increase in the tractive effort for a copper-coated saw blade. The experimentally established values of the magnetic induction in the air gap of the LIASM showed good coincidence with the calculated results from the developed mathematical model.

The Mechanical Analysis of the Composite Reinforced Circular Saw Blade

2011 ◽  
Vol 228-229 ◽  
pp. 484-489
Author(s):  
Xiao Ling Wang ◽  
Zhong Jun Yin ◽  
Chao Zhang
Keyword(s):  
Volume Fraction ◽  
Mechanical Analysis ◽  
Loading Conditions ◽  
Circular Saw ◽  
Model And Simulation ◽  
Circular Saw Blade ◽  
Saw Blade ◽  
Reinforcement Model ◽  
Circular Saws ◽  
Composite Reinforcement

Thinner saw blades cannot resist large lateral cutting forces due to their lower stiffness. In this paper we propose a composite reinforcement method to improve the mechanical properties of circular saw blades. We analyze and simulate the stress and strain fields of our proposed reinforced circular saws by Finite element method. Our analytical results contain not only influences of reinforcing parameters but also loading conditions on the lateral stiffness and the natural frequency of composite saw blades. Here the reinforcing parameters include: 1) the reinforcement location on circular saw blades, 2) the volume fraction of the reinforcements, 3) the number of the reinforcements; and loading conditions include: 1) the cutting force, 2) the rotational speed. Our composite reinforcement model and simulation results can contribute to a better design of circular saw blades.

scholarly journals Analysis of cutting conditions in the process of cross-cutting wood by circular saws

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 1029-1041
Author(s):  
Ján Kováč ◽  
Pavol Harvánek ◽  
Jozef Krilek ◽  
Tomáš Kuvik ◽  
Ján Melicherčík
Keyword(s):  
Wood Species ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Steel ◽  
Rake Angle ◽  
Cutting Conditions ◽  
Sintered Carbide ◽  
Circular Saw ◽  
Saw Blade ◽  
Circular Saws

An analysis was conducted of the effects of cutting conditions in the cross-cutting of wood using circular saws. Gradual wear of the saw blade cutting wedges impacted the entire cutting process. Two different types of circular saw blades were used. One blade type featured sintered carbide tips and 54 saw blade teeth, whereas the other had high-speed steel with 56 teeth; both saw-blades were 600 mm in diameter with a rake angle of 20°. The two wood species were spruce (Picea abies) and beech (Fagus sylvatica). During sawing, the timber was fed at a velocity of vf = 6 and 12 m·min-1. The cutting speed (vc) was set at 60 m·s-1, 70 m·s-1 and 80 m·s-1. The saw blades were coated with three types of PVD coatings. The least energy intensive saw blade was a sintered carbide-free saw blade with a coating (AlTiN) at a displacement speed of 12 m·min-1 and cutting speed of 60 m·s-1 with a power of 1310,63 W. Any change of a saw blade considerably affected torque for all the wood species, so a particular type of saw blade will always have an impact on torque. Other parameters distinctively and individually influenced the process of wood sawing.

A Simulation Model for Analysis of Roll Tensioning of Circular Saw Blade

2014 ◽  
Vol 1018 ◽  
pp. 57-66 ◽  
Author(s):  
Uwe Heisel ◽  
Thomas Stehle ◽  
Hadi Ghassemi
Keyword(s):  
Simulation Model ◽  
Dynamic Behavior ◽  
Dynamic Properties ◽  
Life Time ◽  
Noise Emission ◽  
Hand Tools ◽  
Circular Saw ◽  
Circular Saw Blade ◽  
Saw Blade ◽  
Circular Saws

Circular saw blades are very widespread in wood machining. They are used in different batches and sizes and in large quantities from hand tools to large machining centers. Because of this huge range of applications the circular saws have gained great importance in the industry. The rising request to improve the cutting quality, reduce the noise emission and increase the life time requires improvement measures for the dynamic behavior of the circular saw blade. The roll tensioning of the circular saw blade has been empirically established as an elegant solution to improve the static and dynamic properties of the circular saw blade. However, there are several influencing parameters for this process that have not yet been studied scientifically accurate. A scientific and economical solution for the study of various roll tensioning parameters is a simulation model based on finite elements method (FEM) that analyzes the effects on the dynamic behavior of circular saw blade. In this work, a simulation model for roll tensioning of circular saw blades is presented. With this simulation model, the residual stresses induced by the roll tensioning can be calculated. This is very relevant for the changing of dynamic properties of the circular saw blade, such as the shifting of eigenvalues and reduction of side run out. Furthermore, this simulation model allows the investigation of various roll tensioning parameters. This investigation helps to gain a better understanding of the relationship between roll tensioning and improvement of dynamic behavior of circular saw blades. Furthermore, it helps to find the optimization potential of the roll tensioning process which is one of the most important parts of the production line of circular saw blades.

Feedback Control of Saw Blade Temperature With Induction Heating

1978 ◽  
Vol 100 (2) ◽  
pp. 119-126 ◽  
Author(s):  
C. D. Mote ◽  
S. Holo̸yen
Keyword(s):  
Induction Heating ◽  
Effective Means ◽  
Coil Design ◽  
Transient Heating ◽  
Circular Saw ◽  
Steady State Temperature ◽  
Saw Blade ◽  
Circular Saws ◽  
Axisymmetric Temperature ◽  
Basic Induction

Control of the axisymmetric temperature distribution in a circular saw has been shown to be an effective means of reducing blade vibrations. Theoretical and supporting experimental analyses of a basic induction heating coil design are presented here. An IR thermometer was designed to measure the blade temperature. Transient heating, transient cooling and steady state temperature experiments on circular saws were conducted both in the laboratory and in production. The true set point temperature was maintained to within 2 C.

Active Vibration Control with State Feedback in Woodcutting

2003 ◽  
Vol 9 (6) ◽  
pp. 645-664 ◽  
Author(s):  
Y. Chen ◽  
X. G. Wang ◽  
C. Sun ◽  
F. Devine ◽  
C. W. De Silva
Keyword(s):  
Active Control ◽  
Active Vibration Control ◽  
Raw Material ◽  
Linear Quadratic ◽  
Blade Vibration ◽  
Wood Processing ◽  
Lqg Control ◽  
Active Vibration ◽  
Saw Blade ◽  
Circular Saws

Circular saws are widely used in wood processing for applications ranging from primary lumber manufacturing to furniture industry and home workshops. They directly contribute to production problems such as poor cutting accuracy, poor surface quality, short tool life, high noise levels, and excessive raw material wastage. Vibration of the saw blade during woodcutting has been identified as a key reason for poor wood recovery. In fact, about 12% of the raw material in woodcutting ends up as sawdust due to excessive sawing gap. Efficient wood sawing is being pursued with the objective of mitigating these problems; particularly, to reduce saw blade vibration and sawdust. In this paper, we present active control of saw blade vibration using linear quadratic Gaussian (LQG) control. We outline a test rig that has been developed for our experimental investigation. The system configuration is described and the control problem is formulated. The experimental procedure for identification of a system model is described. The implementation of the LQG control scheme is outlined, and typical results from the experimental control system are presented and discussed. The developed controller is shown to be very effective in the present application, as evident from the results that have been obtained. In particular, the amplitude of the saw blade vibration has been reduced by 66% on average using active control, compared to cases with no control. Also, the cutting gap (kerf) has been reduced by 25%, from 2.00 mm to 1.50 mm, through active control. In terms of 1995 prices, this would correspond to an increased revenue of $640,000 per year for a mill producing 100 MM fbm of lumber annually.

scholarly journals Reducing the Energy Consumption of Circular Saws in the Cutting Process of Plywood

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 55
Author(s):  
Jozef Fekiač ◽  
Ján Svoreň ◽  
Jozef Gáborík ◽  
Miroslav Němec
Keyword(s):  
Energy Consumption ◽  
Surface Temperature ◽  
Cutting Conditions ◽  
Cutting Process ◽  
Feed Speed ◽  
Cutting Power ◽  
Wood Processing ◽  
Circular Saw ◽  
Circular Saw Blade ◽  
Saw Blade

Cutting, as the most widely used machining process, is applied in both primary and secondary wood processing. Optimum cutting conditions that result in the high quality of the machined surface and low energy consumption are crucial for wood processing. The effects of the feed speed, cutting speed and average chip thickness on the energy consumption and surface temperature of a circular saw blade during the cutting process of two types of plywood with a thickness of h = 14 mm is described in this paper. In experimental measurements, two circular saw blades with cutting tungsten carbide inserts for wood were used as tools. One circular saw blade was standard, and was not surface treated (CSB1), and second circular saw blade (CSB2) differed by the powder coating surface and the length of the cutting edge. In the experiment, the energy consumption and the surface temperature of the circular saw blade was measured in order to find the optimal cutting conditions for the most energy-efficient cutting process. The results show that the cutting power and the surface temperature of the circular saw blade increased when the feed speed increased. The investigated values of the surface-treated circular saw blade were lower compared to the values of the standard circular saw blade. When comparing the lightweight plywood with the classic plywood, experimentally obtained cutting power values of the circular saw were made 19% lower on average by using the circular saw blade CSB1. When using the CSB2 circular saw blade, these values of the cutting power of the circular saw were 22% lower on average. The surface temperature of the circular saw blade is the highest on the outer edge (tooth root area 31.7 °C) and decreases towards the center of the circular saw blade. There must be a reasonable compromise between machine productivity and energy consumption.

scholarly journals COMPARISON OF SAW BLADE NATURAL FREQUENCIES AND CRITICAL SPEEDS USING CSAW AND FINITE ELEMENT ANALYSIS

2011 ◽  
Author(s):  
J. Poirier ◽  
P. Radziszewski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Saw Blade ◽  
Circular Saws ◽  
The Finite Element Model ◽  
Element Method

The natural frequencies of circular saws limit the operating speeds of the saws. Current industry methods of increasing natural frequency include pretensioning, where plastic deformation is induced into the saw. To better model the saw, the finite element model is compared to current software for steel saws; C-SAW, a software program that calculates frequencies for stiffened circular saws. Using C-SAW and the finite element method the results are compared and the finite element method is validated for steel saws.

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