Rotary Cutter Research Articles

Characterization of noise emitted by a low-profile tractor and its influence on the health of rural workers.

Noise is one of the main physical agents in the rural work environment and it can be harmful to the health of workers exposed to it. Thus, research on the spatialization of noise emitted by agricultural machinery can help minimize harmful health effects. This study sets out to evaluate the spatial distribution of the noise emitted by an agricultural tractor with and without the activation of a rotary cutter. A wave model geostatistical analysis was used to identify healthy working zones according to current legislation. The experiment was carried out using a 75 hp tractor at 2000 rpm with the rotary cutter on the on and off modes. A digital sound level meter was used to register noise in a regular 2.0 x 2.0 m sample mesh within a 10-meter radius. The semivariogram was adjusted using the weighted least squares method, wave model and kriging interpolation to obtain the maps. The magnitude and spatial structure of the noise emitted by the tractor were identified. The results show that the equipment produced noise levels above the limits recommended by Brazilian regulatory standard NR 15. Thus, both the machine operator and the workers involved in the operation should use Personal Protective Equipment.

Experimental Study on the Soil Conditioning Materials for EPB Shield Tunneling in Silty Sand

Earth pressure balance (EPB) shield tunneling in a silty sand stratum is frequently faced with the wear of rotary cutter disc, clogging, or even collapse of workface due to its noncohesive and discrete properties of silty sand material. Soil conditioning is an effective way to reduce the discrete and friction properties of silty sand and to increase its rheology and fluidity, thus improving the cutting performance of EPB machines. However, soil conditioning materials were generally prepared and injected based on past limited field experiences or lab tests which were far from reality. In this article, a ground suitability test system for simulating shield tunneling in a conditioned ground was specially developed and used in a series of tests to investigate the influences of key factors of soil conditioning on the shield cutting performance. In addition, a field experiment of shield tunneling in silty sand of Wuhan Metro was conducted for verification. The major findings were obtained as follows. (1) The proposed test system performed well in simulating and assessing the cutting performance of EPB shield in conditioned soils, and the test results agreed well with the field test. (2) The soil conditioning materials can significantly reduce the cutting torque of shield tunneling in silty sand by up to 60%–70%. (3) The optimal foam and slurry parameters are suggested in the paper for shield tunneling in silty sand, respectively. (4) The test results reveal that the slurry conditioning is better than the foam in decreasing the cutter torque in silty sand. To achieve the same effect of soil conditioning, the injection ratios of foam and slurry should be 45% and 10%, respectively, to achieve the torque reduction ratio of 60%. These findings can provide a practical reference for engineers to determine the best‐fit conditioning materials and construction parameters in the silty sand stratum.

DEVELOPMENT OF ELECTRONIC CAM MOTION CONTROL FOR SYNCHRONOUS CUTTING SYSTEM

Before the introduction of electronic motion controls, the traditional mechanical camwas the best approach to be used in applications that perform repetitive operations. Where theunique feature of the cam system is that the master-follower relationship is always repeated.When the electronic motion control system was introduced, the ability to duplicate the functionof the mechanical cam becomes possible by electronic control drives called electronic cams.Limitation of speed, accuracy, and random space are some of the problems faced by mechanicalcam. This study made a prototype of the high-speed rotary synchronous cutting system usingelectronic cam feature of motion controller Yaskawa MP-3000 Series with Sigma-7 servosystem. This study has obtained and analyzed a model of the high-speed rotary cutting system,successfully controlled the rotary cutter motion and proved an alternative cam motion operationwith electronic cam motion control. Performance and precision test for high-speed system needto be improved for the future study.

Latex Glove Samples Cutting System with Rotary Cutter Mechanism

In this study, it involves the protein determination of latex gloves for latex glove manufacturing industry. Natural rubber latex (NRL) gloves provide tactile properties, barrier protection, tear resistance, economy and comfort touch surface area which preferred by the medical field. However, there are more than 200 proteins in the NRL and 13 of them which are known to be allergens to human. In the manufacturing process of latex gloves, the Bradford reagent protein test method is used as a standard method for assessing protein levels for quality control. The current standard methods typically involve many procedures that manually operate which results in high processing time. Thus, new innovative design is needed and involved the cutting system that allows samples stamping and retrieved with less time consumption. The cutting machine can perform the automatic cutting of latex glove into several samples According to the current method, samples cutting process conducted by humans. Therefore, the new system is automated, which may only require an operator to place the glove at the input of the system and remove it at the end of the process. The new latex glove samples cutting system consists of Computer Numerical Control (CNC) moving mechanism with a 28 mm rotating rotary cutter as cutting die. Thus, the cutting system is able to shorten the processing time on protein determination

Percutaneous Vertebroplasty Using Rotary Cutter for Bone Metastases

Percutaneous Vertebroplasty Using Rotary Cutter for Bone Metastases

Shredding as simultaneous size-reduction and tribo-charging operation for improved performances of an electrostatic separation process for granular plastic wastes

Triboelectrostatic separation is a technology which allows the selective sorting of polymer materials based on their surface charging characteristics. Before they are subjected to electrostatic separation, the materials to be sorted are reduced to a proper size (typically less than 5 mm). The present paper aims to evaluate the possibility of using shredding as simultaneous size-reduction and tribo-charging operation and examine the effect of shredding and size reduction on triboelectric charging and electrostatic separation efficiency. The study was performed on typical pieces of PC-ABS and HIPS originating from waste electric and electronic equipment (WEEE). Experiments start by feeding equal quantities of plastic pieces into the shredder. The rotary cutters of the shredder stir the plastic pieces, a charge transfer occurs between the plastic particles by repeated collisions and rubbing against each other. After a certain time, a granular mixture was recovered from the shredder and immediately introduced in a roll type triboelectrostatic separator. The charge of the selectively sorted products was measured using a Faraday cage connected to an electrometer. Four screen mesh diameters were compared (2 mm, 3 mm, 5 mm, and 7 mm). The experimental results confirm that granules can get enough charge during shredding for being successfully sorted by the roll-type electrostatic separator. Particle size is definitively an important factor influencing the outcome of the triboelectrostatic separation. Fine shredding is not favorable, as it requires shredding for extended periods and favors the formation of particle agglomeration. High separation efficiency was obtained for relatively coarse particles.

Improving efficiency of machining the geometrically complex shaped surfaces by milling with a fixed shift of the cutting edge

In order to improve efficiency of machining by milling geometrically complex shaped surfaces, mainly the methods related to improvement of properties of the tool material, change of composition and properties of the tool surface layer, application of thin film coatings, reduction of roughness of the working surfaces and improvement of operating conditions of the tool using lubricant-cooling media are mainly used. Proceeding from the above stated, scientifically grounded technical and technological solutions consisting in development of a new highly effective method for machining geometrically complex shaped surfaces by means of disk rotary cutters with a reciprocatively rocking feed motion were studied and set forth in this work. This machining method can increase the period of durability of tools by 1.7 times and milling performance by 1.6 times by means of a fixed kinematic shift of the cutting edge relative to the machined surface. A mathematical apparatus of the method of milling with a fixed shift of the cutting edge was proposed. Analysis of this method with the help of numerical functions has enabled establishment of analytical dependences for determining thickness and volume of a unit cut-off layer. Thickness of the cut-off layer is mainly affected by feed per tooth, Sz, and the angle υ influences its volume which determines normal cutting conditions. A model of distribution of heat flows in the cutting wedge for the method of milling with a reciprocatively rocking feed motion taking into consideration the amplitude of rocking motion of the workpiece was studied. A temperature decrease to 330.2...395.5 °C was established, that is by 80.6...181.6 °C for the stamp steel 9CRSI and to 193.8...285 °С, that is, by 56.6...120.2 °C for steel 45 compared to conventional milling. It was found that total length of the cutting edge increases 2.4 times with 1.5 times temperature decrease

Percutaneous Kyphoplasty Using Rotary Cutter in Osteoporotic Vertebral Fractures

Percutaneous Kyphoplasty Using Rotary Cutter in Osteoporotic Vertebral Fractures

Automatiс Operation of a Rotary Garden Cultivator

Abstract.The paper discusses the advantages of power-driven tillage tools as compared with machines with passive working elements, which provide for quick changing and controlling of the quality of soil crumbling, guided by the condition of the treated areas and the engine power of the power source used. (Research purpose) To develop a system for automatically maintaining the magnitude of a selected kinematic parameter during the operation of a rotary cultivator equipped with a hydraulic drive of working elements. (Materials and methods) The authors have conducted research involving patented materials on the use of automated process control systems for pre-sowing soil cultivation with tools featuring hydraulic actuators of working elements. (Results and discussion) It has been determined that the frequency comparison blocks may contain pulse shapers that are converted by the electronic control unit into a signal sent to a low-speed, high-torque adjustable motor of a Danfoss MGP-160 type. A system has been developed to automatically maintain the value of a selected kinematic parameter of a rotary cultivator by equipping its working elements with a hydraulic actuator with a two-stage hydraulic distributor controlled by an electronic unit that allows automatic adjustment of the required speed of the rotary drum cutters, optimal for the treated soil background. (Conclusions) The authors have identified a schematic diagram of an automated hydraulic drive of a rotary garden cultivator capable of tracking and adjusting the rotary drum speed.

Numerical and Analytical Calculations for Modeling and Designing Drilling Wicks or Rotary Cutters Based of Functionally Graded Materials

Drilling tools or drilling pipes, such as drill bit and mill drill, are often subjected to various forces, including essentially tangential forces, centered on their axis of rotation. The main objective of this work is to find analytical and numerical solutions of the distribution of stress field, deformation, and displacement, when such tools are subjected to such forces. It will be assumed that the instrument in the chosen model in this work is a rotating hollow cylinder constructed from a Functional Graded Material (FGM). Because of the graduation of the FGM, the mechanical and elastic properties such as Young’s modulus, density, and Poisson’s ratio vary in the radial direction according to a power law function. By choosing that the inhomogeneity parameter is between -0.5 and 0.5, we have established the differential equation which describes the equilibrium of the hollow cylinder in rotation under an axial load. The calculations performed have allowed finding an analytical solution which was compared with numerical solutions obtained by using the shooting method and the fourth-order Runge-Kutta algorithm. These analytical and numerical results have shown that the values of tangential stresses are greater than the radial stresses. The radial stresses and tangential and vertical stresses progressively increase with the axial force Fz. The force Fz affects more tangential stresses that the radial stresses. The tangential stress, tangential deformations, and displacements are higher on the inner walls of the cylinder than on the exterior surfaces. The results obtained are very important and can be applied in the modeling and designing wicks and drilling strawberries in order to reduce their rapid wear and damage.

Study on the overcut errors of milled freeform microarray related to cutter micro-cutting-edges

The microstructures need to be machined on macro freeform surface by the macro and micro tools in different conditions, respectively, thus leading to inefficiency and high cost. The micron-scale cutting-edges ground on rotary macro ball-end cutter is proposed to be replicated on the workpiece freeform surface through 5-axis milling, but it has not been clear about the geometrical relationship between the ground micro-cutting-edges and the milled freeform microstructures due to the overcut in linear and rotational linkages. Hence, the geometric model of milled freeform microarray is proposed by the geometric parameters of cutter micro-cutting-edges. The objective is to understand how the milled freeform microarray is formed in connection with the spatial overcut between cutter and workpiece in 5-axis movement. First, the diamond wheel micro-tip was employed to grind the integrated and smooth micro-cutting-edges on cutter surface; then the cutter was used to perform the 5-axis milling; finally, the milled freeform microarray with the height in 97 μm and the angle in 80.5° was evaluated. It is shown that the cutter micro-cutting-edge angle is equal to the wheel micro-tip angle in micro-grinding without any overcut, or it is dominated by wheel radius, wheel micro-tip angle, cutter radius, and cutting-edge position angle. In 5-axis milling, the freeform microarray angle is equal to the wheel micro-tip angle when the cutting-edge position angle is larger than a critical value, or it increases with decreasing the cutting-edge position angle due to the milling overcut. Moreover, the actual microarray height is smaller than the theoretical value due to the overcut of tool axis changing. The milling errors of freeform microarray height and angle averagely reached 5.2 μm and 2.2°, respectively. As a result, the freeform microarray may be designed by wheel micro-tip angle, micro-grinding variables, and milling variables.

The Improvement of the Rotary Tillers’ Blade Design and Analysis

As we know ,The shape of the rotary tiller blade ,Parameter and materials directly influences the Mechanical property of the rotary blade and then influence the rotary cultivator’s work efficiency And energy consumption[1] .Based on compared with china and foreign countries’ rotary tillage cutter Arrangement and analysis of advantages and disadvantages ,Slightly improved the structure of the Existing rotary tillage blade in the laboratory ,Analyzed the force of rotary tillage blade during the Working process ,Simulated the real working condition and make the load to the rotary blade then Analyzed the stress-strain from the rotary blade’s surface .Based on the collected data we can give Some advice to the designer like what we should focus on addition and consideration when we need To design rotary blade .Which provided the theoretical basis to the rotary blade structural Optimization in the future.

Theoretical study of cut area of reduction of large surfaces of rotation parts on machines with rotary cutters “Extra”

Large parts can be treated without disassembling machines using “Extra”, having technological and design challenges, which differ from the challenges in the processing of these components on the stationary machine. Extension machines are used to restore large parts up to the condition allowing one to use them in a production environment. To achieve the desired accuracy and surface roughness parameters, the surface after rotary grinding becomes recoverable, which greatly increases complexity. In order to improve production efficiency and productivity of the process, the qualitative rotary processing of the machined surface is applied. The rotary cutting process includes a continuous change of the cutting edge surfaces. The kinematic parameters of a rotary cutting define its main features and patterns, the cutting operation of the rotary cutting instrument.

A post-processing study on aluminum surface by fiber laser: Removing face milling patterns

The face milling process of the metal surface is a well-known machining process of using rotary cutters to remove material from a workpiece. Flat metal surfaces can be produced by a face milling process. However, in practice, visible, traced marks following the motion of points on the cutter’s face are usually apparent. In this study, it was shown that milled patterns can be removed by means of 20 W fiber laser on the aluminum surface (AA7075). Experimental results also showed that roughened and hydrophobic surface can be produced with optimized laser parameters. It is a new approach to remove the patterns from the metal surface and can be explained through roughening by re-melting instead of ablation. The new method is a strong candidate to replace sandblasting the metal surface. It is also cheap and environmentally friendly.

Possible ways to expand range of rock strength, destroyed by cutter bit

The strength analysis of the rotary tangential cutter in the conditions of rock destruction has shown that the stresses in the most dangerous section of the tool (at the junction of the head and shank of the holder) are distributed, mainly, near the surface. This makes it possible to increase the overall strength of the tool by making its holder in the form of a bimetallic construction, the shell of which is made of high-strength material, and the core of a highly viscous, not necessarily durable material. By the example of the RKS-2 it is shown that the use of a bimetallic holder extends the range of tool work on rocks with a strength up to f = 8.

Shape optimization of generic rotary tool for five-axis flank milling

This paper presents an approach to optimize the shape of a general rotary cutter for five-axis flank milling of ruled and non-ruled surfaces. Based on the observation that tool shape optimization is equivalent to repositioning the control points of its B-spline meridian, the optimization of tool surface is reduced to that of a B-spline curve. Then, the meridian of rotary tool surface is represented by cubic B-spline curve, and it is used to obtain the analytic tool envelope surface. Subsequently, the flank milling error is measured by the distance between a point sampled from envelope surface and the design surface. On this basis, shape optimization of a general rotary cutter is formulated as an optimization problem from the perspective of approximating the tool envelope surface to the designed surface. Two examples are given to confirm the validity of the proposed method. The approach also applied to multi-pass five-axis flank milling.

The investigation of the influence of thermomechanical treatment of the material of rotary cutter bit toolholders on its hardness

The causes of failure of the tangential rotary cutter bits of the road header during stonedrift in rocks of medium strength are analyzed in the article. It was revealed that the most typical cause of failure of cutter bits is premature wear of the toolholder (body) of the cutter bit. It is well known that the most effective way to improve the wear resistance is to increase hardness. The influence of the thermomechanical treatment of the material of the cutter bit toolholder on its hardness is studied. It was established that the thermomechanical treatment of the cutter bit toolholder material results in the increase of its hardness. It was found that the increase of material hardness is proportional to the increase of material strain intensity during thermomechanical treatment. It was concluded that the use of thermomechanical treatment can lead to the increase of both the hardness and wear resistance of the cutter bit material.

Taguchi-based robust design for the footwear outsole pelletizing machine cutter

Purpose This study attempts to find out the optimum condition of the rotary cutter making pellet in the footwear outsole process. The pellets are used in the process of outsole rubber fabrication to reduce cycle time and save raw material. Methods Computer simulations are used to analyze the maximum stress in the rotary cutter after designing a variety of cutter shapes. Taguchi method is used to identify the robust condition of the cutter. In L18 orthogonal array, the control factors such as knife width, twisted angle, number of knives, diameter, knife depth and supported angle are considered and noise factors like assembly tolerance and amount of antifriction are allocated. Results It is found that the most important factors to reduce maximum stress in the cutter are supported angle and diameter. Using Tacuchi's results, we can reduce 70% cycle time and 9% raw material compared to the traditional method using cutting die. Conclusion When designing the rotary cutter, the best conditions are the diameter at its maximum allowable value and supported angle in the boundary of machine inner space. Key words: Robust Design, SN(signal to noise) Ratio, Taguchi Method, CAE(Computer Aided Engineering)

Design of Electrolytic Strengthening Machine for Cutting Edge of Cutter

Many studies have proved the service life of cutter can be prolonged by electrolytic strengthening. Based on the theory of electrolytic strengthening technology, this paper introduced and developed prototype equipment for strengthening cutting edge of rotary cutter and put forward a calculation method of total electric quantity consumption during the electrolysis suitable for microcontroller. The M8 high-speed steel tap is taken as a strengthening example. After finished the strengthening process that it clearly see the results of the surface of tap was obviously polished by observing the micrograph. This equipment improves the reliability of electrolytic strengthening and the cost is relatively cheap.

Chondrocyte survival in osteochondral transplant cylinders depends on the harvesting technique.

In autologous osteochondral transplantation, the edges of the harvested plug are particularly susceptible to mechanical or thermal damage to the chondrocytes. We hypothesised that the applied harvesting device has an impact on chondrocyte vitality. Both knees of five blackhead sheep (ten knees) underwent open osteochondral plug harvesting with three different circular harvesting devices (osteoarticular transfer system harvester [OATS;diameter 8mm; Arthrex, Munich, Germany], diamond cutter [DC; diameter 8.35mm; Karl Storz, Tuttlingen, Germany] and hollow reamer with cutting crown [HRCC; diameter 7mm; Dannoritzer, Tuttlingen, Germany]) from distinctly assigned anatomical sites of the knee joint. The rotary cutters (DC and HRCC) were either used with (+) or without cooling (-). Surgical cuts of the cartilage with a scalpel blade were chosen as control method. After cryotomy cutting, chondrocyte vitality was assessed using fluorescence microscopy and a Live/Dead assay. There were distinct patterns of chondrocyte vitality, with reproducible accumulations of dead chondrocytes along the harvesting edge. No statistical difference in chondrocyte survivorship was seen between the OATS technique and the control method, or between the HRCC+ technique and the control method (P > 0.05). The DC+, HRCC- and DC- techniques yielded significantly lower chondrocyte survival rates compared with the control method (P < 0.05). Chondrocyte survival in osteochondral cylinders depends on the applied harvesting technique. The use of rotary cutters without cooling yielded worst results, while the traditional OATS punch and rotary cutters with cooling achieved comparable rates of chondrocyte vitality.