Spiral Drill Research Articles

Smash-ridging cultivation improves crop production

Smash-ridging cultivation is an efficient farming method that was recently developed in China. The technique involves vertically cutting by using a spiral drill, causing the soil to ‘suspend’ as ridges, thereby breaking through the traditional plough pan, and thickening the plough layer up to 30–50 cm. Smash-ridging cultivation has effectively improved soil quality and has increased the water and nutrient retention capacity. Loose soil enables the plant’s root system to optimally develop and more efficiently absorb nutrients. This facilitates the growth of the above ground parts of plant, leading to a significant increase in crop yield. This method has been successfully applied on 40 crops and tested in 26 provinces. The yield increase within a single season ranges from 10.0% to 54.8%. This technique may have a positive and extensive impact on food safety and agricultural production in China and the rest of the world.

Ovrednotenje uporabnosti tehnološkega postopka izdelave spiralnih svedrov

The current world trends and the global market require production organizations to increase the quality while reducing the costs of their products. In most cases, traditional production technologies of spiral drill bits (SD) cannot meet these expectations, as they most often fulfil only one of the set requirements. Thus, the cost of a SD produced with the rolling technology is low, but its quality is also much lower than that of the drills produced with the grinding technology whose cost is also much higher. The grooves of the SDs produced with our new technological method have advantages over the grooves produced with the rolling technology or grinding technology, and the savings in the material and grinding wheel are higher compared to the SDs produced with the grinding technology. This paper presents an analysis of the application of this new technological process for producing SD grooves.

Research on drilling process technology and parameter optimization in soft coal seam

Due to the low firmness coefficient of soft coal seam and the influence of formation pressure and in-situ stress, it is easy to cause hole collapse in bedding drilling, resulting in low hole forming rate and insufficient hole forming depth, so the drilling technology needs to be improved. This paper focuses on the study of hole forming technology and parameters of bedding drilling in soft coal seam. The research results show that: the key to improve the construction efficiency of bedding drilling in soft coal seam is to improve the slag removal ability of drilling engineering, and the drilling technology of spiral drilling and pressure air slag removal is conducive to improve the drilling depth and drilling effect. The hole forming process and parameters of spiral drilling and pressure air slag removal are systematically described. The drill pipe speed, the coal conveying capacity in the hole, the minimum wind speed of pressure air slag removal and the air supply pressure of slag removal are determined. It is of great practical significance to develop and improve the drilling technology of bedding hole drilling in soft coal seam to improve the gas drainage capacity of coal mine and the drilling depth and rate of bedding hole drilling in soft coal seam.

МОДЕЛЬ ПРОГНОЗИРОВАНИЯ ОСЕВОЙ СИЛЫ РЕЗАНИЯ ПРИ СВЕРЛЕНИИ ОДНОНАПРАВЛЕННЫХ УГЛЕПЛАСТИКОВ С УЧЕТОМ ИЗНОСА РЕЖУЩЕГО ИНСТРУМЕНТА

One of the most important tasks in the production of carbon fiber products is to ensure the specified accuracy and quality of the drilled holes. A model for predicting the thrust force, taking into account the degree of tool wear, is proposed. First, the geometric characteristics of the wear of the spiral drill tool are analyzed. Further, the contact conditions between the drill and the carbon fiber are determined in accordance with the geometric characteristics of the tool wear. Based on the mechanics of the contact interaction of surfaces, the thrust forces of the main cutting edges and the chisel edge are modeled, taking into account the degree of tool wear. The results obtained are integrated into the thrust force prediction model. An example of an experimental study of the drilling carbon fiber is given. The results obtained show a fairly accurate prediction of the cutting force, taking into account the wear of the cutting tool.

IMPROVEMENT OF TECHNOLOGICAL PROCESS OF DRILLING THIN SHEET STEELS

This article considers the technological process of drilling holes in sheet metal. The existing typical technological process, with detailed analysis, provides grounds for substantiating the idea of an innovative solution. There is a connection between the improvement of economic indicators of this technological operation with the change of geometric parameters of the tool. The comparison of existing technological processes, operations, and transitions of production of round openings with the use of spiral drills is given. The traditional technique involves a clear sequence of the technological process with the use of tools for marking, kerning, and sequential use of screw drills of different diameters. Therefore, after the previous operation of marking the center of the two holes, perform the operation of kerning. The core (recess in the metal) prevents the deviation of the small diameter screw drill from the marking lines. After the above steps, the traditional technological process involves drilling a small diameter hole in order to direct the main tool in the right direction. To make the main hole perform special sharpening of the working part of the twist drill so that the diameter of the Central part of the tool is equal to the diameter of the first guide hole to avoid further displacement of the main hole and the next operation is to drill the hole to the desired diameter. As a result, the article raises the topic, given the widespread use of sheet metal, including in the agricultural sector, the feasibility of using an innovative idea to improve the technological process associated with the processing of sheet material, namely thin metal sheets. It is worth noting that for example, we consider a material that is characterized by its versatility, namely steel Ст 3. Despite the numerous sources devoted to the study of improving the drilling process, there are a number of issues, including the extension of this direction surfaces with a covering and without it, various thicknesses within the thin-walled hire. The most significant result of the improved technological process of drilling will be used in the system of efficient maintenance of agricultural machinery.

A retrospective case series report on a novel aggressively threaded and tapered implant

Background: Firm primary implant stability is considered as one determinant of success with implant therapy. A novel tapered implant with aggressive threading aiming at high primary stability, also in low bone densities, using a simplified drilling protocol has recently been developed. Aim/Hypothesis: To retrospectively evaluate the primary stability, clinical and radiographic performance of 25 tapered and aggressively threaded implants in 15 consecutive patients after one year of follow-up. Materials and Methods: The study comprised of the first 15 consecutive patients (13 female, 2 male) treated with 25 implants (Proactive Edge, Neoss AB, Gothenburg, Sweden) using a one-stage protocol and loaded for at least one year (Figures 1 and 2). Five implants had been placed in the mandible and 20 in the maxilla for seven single tooth replacements, seven partial bridges and one full bridge. Insertion torque/time curves were registered during placement with an Elcomed drilling unit (W&H Austria GmbH, Bürmoos, Austria). RFA measurements were taken after implant placement using a PenguinRFA instrument (IDSAB, Gothenburg, Sweden). The implants were either restored immediately (n = 5) or after 6 to 8 weeks of healing (n = 20). Marginal bone levels were evaluated in baseline and one-year intraoral radiographs. Results: All implants achieved firm primary stability as assessed with insertion torque (42.6 + 17.0 Ncm, range 13-80 Ncm) and RFA (76.9 + 3.7 ISQ, range 66-84 ISQ) measurements. Thirteen of the implants (all 3.5 mm in diameter) could be placed after the use of one spiral drill only. The remaining implants (4.0 mm, n = 10, 5.0 mm, n = 2) were placed after using two spiral drills. No implant was lost during the one-year of follow-up. The mean marginal bone resorption was 0.5 + 0.6 mm after one year. Conclusions and Clinical Implications: The present case series report showed that the novel implant and simplified drilling protocol resulted in firm primary implant stability. Promising clinical and radiographic outcomes were seen after one year. However, clinical studies including more patients and implants are needed. Keywords: dental implants, primary stability, clinical follow-up, case series Figure 1: The Neoss Proactive Edge implant in different diameters, Figure 2: Postoperative (left) and one-year (right) intraoral radiograph of one implant used for a maxillary molar replacement.

Exploring Deep‐Rock Mechanics through Mechanical Analysis of Hard‐Rock In Situ Coring System

Exploration of deep‐rock mechanics has a significant influence on the techniques of mining and rock mechanics. Rock coring technique is the basic method for all rock mechanics study. With the increase of the drilling depth and increasing strength of the hard rock, how to obtain high‐quality rock core through various coring techniques is an eternal work. Here an innovative method is applied to design the new coring system to maximize the efficiency of operation. The stress conditions or parameters of rock core in the coring are analyzed, and the mechanism of the core with in situ stress is shown in this paper. The conflict of the core and coring tool chamber is proposed for the innovative design. The innovative design method is fulfilled by the theory of inventive problem solving (TRIZ). An improved coring system for the full‐length core with in situ stress was obtained with the solutions of improved coring mechanism, cutting mechanism, and spiral drill pipe.

Vibration suppression methods at high performance drilling

This article discusses the possibility of suppressing vibrations when drilling holes with spiral drills. This article presents two methods of suppressing vibrations: modal analysis and modulation of cutting speed (changes in spindle speed - Spindle Speed Variation - SSV). There is a description of the considered methods with an indication of their advantages and disadvantages. The article also points out to experimental data that characterize the possibility of suppressing vibrations when drilling holes and a comparative analysis of various methods of suppressing vibrations when machining holes in samples of their structural steel. There is an assessment of the possibility of joint application of modal analysis methods and modulation of cutting speed during high-performance drilling.

Experimental and theoretical research on drilling epoxy granite using coated and uncoated carbide spiral drill bits

Hard materials with superior physical and mechanical properties, such as epoxy granite, are used in the base of machine tools and precision instruments, where vibration damping properties of epoxy granite has been used. However, epoxy granite drilling is still in its incipient stage of research, due to its heterogeneity, anisotropy and brittleness. The main objective of this study is to analyze the effects of the drilling process parameters, i.e. drilling forces and torques, wear and surface roughness during the drilling process of epoxy granite. It was studied diamond drill bits, twist drill bits with brazed carbide plates, spiral solid carbide drills (with different apex angles of 110°, 120° and 130°). Also were studied spiral solid carbide drill bits coated with (TiAl)N and solid carbide spiral drill bits coated with (TiAl)N + NbHfTi. The experimental data showed that, forces acting on the flank face are greater than the forces acting on rake face of the drill bits. It was also concluded that, coating the carbide spiral drill bits with (TiAl)N + NbHfTi has improved tool life in comparison with uncoated spiral solid carbide drill bits and the spiral solid carbide drill bits coated with (TiAl)N. Wear of uncoated drill bits takes place faster (1.5–2 times) than coated drill bits with (TiAl)N, and up to 3–4 times faster than the drill bits with (TiAl)N coating + NbHfTi treatment.

Application of Discrete Wavelet Decomposition in Monitoring of Hole-making Inconel 718

The paper describes an application of discrete wavelet decomposition of monitored signals from Profibus data originating from spindle and from the feed drive of machine tool. Discrete wavelet decomposition is a most efficient method to separate uniform signal pattern from disordered signal. It was demonstrated that - compared to the evolution of average spindle torque over the tool path - extracted signal variance from the spindle torque through application of wavelet transformation has a significantly higher correlation with maximum flank wear on the tool. Within the framework of tools and cutting conditions chosen in this work, this is true both for drilling with spiral drills and for finishing with face-cutting finishers.

Experiments for Selecting the Optimal Foam Drilling Fluid Formula

Drilling gas-drainage holes in soft coal seams is essential for preventing coal and gas explosions. After analyzing and summarizing the advantages and disadvantages of existing spiral drilling and wind-pressure drilling processes, a new technology of drilling in soft coal seams using a foam drilling fluid is proposed in this paper. Experiments were conducted to determine the optimal drilling fluid formula for drilling to depths greater than 200 m. The most effective foam stabilizers are selected and correlations of foam half-life and volume with stabilizer concentration were found. Based on an analysis and comparison of all drilling fluid formulas, the recommended additives are 5% K12 + 0.6% Sesbania powder + 1.0% Konjac powder or 5% K12 + 0.8% Sesbania powder + 1.0% HEC. In field tests, five holes deeper than 200 m were drilled successfully by using this formula.

Highly Accurate Hole Making Technology of Ti6Al4V by Orbital Drilling: Effect of Oil Mist

Ti6Al4V, which is one of difficult-to-cut metals, is widely used in an aircraft structure, parts of a gas turbine and medical equipment, and hole making operation of Ti6Al4V is needed to fasten the parts. When a conventional drilling by twist drill is applied to hole making of Ti6Al4V, it is very difficult to obtain highly accurate hole in diameter, roundness and inlet - outlet edge quality due to a cutting temperature increase caused by a small heat conductivity of Ti6Al4V.Recently, it is well-known that Orbital drilling, which is also called Circular milling, Planetary drilling or Spiral drilling, is superior to conventional drilling for hole making of Ti6Al4V. The author newly developed a hole making machine to enable orbital motion based on Double Eccentric Mechanism so that an endmill driven by one built-in AC motor can rotate clockwise on its own axis at high speed, simultaneously can revolve counter-clockwise on eccentric axis at low speed (Yagishita, 2015).This paper deals with highly accurate hole making technology of Ti6Al4V by employing the machine and a new type cemented carbide endmill having 6 blades. By supplying oil mist from the tip of endmill using a hole through spindle, it is ascertained that cooling by oil mist is strongly effective in order to improve the deviation of hole diameter and roundness, and also edge quality at inlet and outlet of hole.

Characteristic Analysis of Spiral Drilling and Simulation for Soft Rock Floor Rig

Characteristic Analysis of Spiral Drilling and Simulation for Soft Rock Floor Rig

A Spiral Microrobot Performing Navigating Linear and Drilling Motions by Magnetic Gradient and Rotating Uniform Magnetic Field for Applications in Unclogging Blocked Human Blood Vessels

This research proposes a navigating and drilling spiral microrobot actuated by a magnetic gradient and rotating uniform magnetic field to unclog blocked human blood vessels. The proposed spiral microrobot consists of a cylindrical body that contains a cylindrical magnet and spiral drilling blades on the shaft. The cylindrical magnet can rotate freely inside the magnet slot of the body and align in any direction by applying an external uniform magnetic field. The spiral microrobot is prototyped by 3-D printing technology with ultraviolet curable acrylic plastic, then demonstrated by various experiments. These experiments show that the proposed microrobot successfully performs navigating and drilling motions, thus validating the effectiveness of the proposed spiral microrobot.

An experimental evaluation of loads occurring during guided drilling for cochlear implantation.

During guided drilling for minimally invasive cochlear implantation and related applications, typically forces and torques act on the employed tool guides, which result from both the surgeon's interaction and the bone drilling process. Such loads propagate through the rigid mechanisms and result in deformations of compliant parts, which in turn affect the achievable accuracy. In this paper, the order of magnitude as well as the factors influencing such loads are studied experimentally to facilitate design and optimization of future drill guide prototypes. The experimental setup to evaluate the occurring loads comprises two six degree of freedom force/torque sensors: one mounted between a manually operated, linearly guided drill handpiece and one below the specimens into which the drilling is carried out. This setup is used to analyze the influences of drilling tool geometry, spindle speed as well as experience of the operator on the resulting loads. The results reveal that using a spiral drill results in lower process loads compared with a surgical Lindemann mill. Moreover, in this study, an experienced surgeon applied lower interaction forces compared with untrained volunteers. The measured values further indicate that both the intraoperative handling of the bone-attached drill guide as well as the tool removal after completing the hole can be expected to cause temporary load peaks which exceed the values acquired during the drilling procedure itself. The results obtained using the proposed experimental setup serve as realistic design criteria with respect to the development of future drill guide prototypes. Furthermore, the given values can be used to parameterize simulations for profound stiffness analyses of existing mechanisms.

Hole Making Machine Based on Double Eccentric Mechanism for CFRP/TiAl6V4 Stacks

Construction parts consisting of 2-layer composite materials made of carbon fiber reinforced plastic (CFRP) laminates and TiAl6V4 still need to be machined, whereby drill holes are frequently manufactured. Recently, it is well-known that Orbital drilling, which is also called Circular milling, Planetary drilling or Spiral drilling, is superior to conventional drilling for hole making of CFRP/TiAl6V4 stacks. The author newly developed hole making machine based on Double Eccentric Mechanism so that a cutting tool driven by one built-in air motor can rotate clockwise on its own axis at high speed, simultaneously can revolve counter-clockwise on eccentric axis at low speed (Yagishita, 2012). The driving mechanism of the machine is entirely different in that respect both high speed rotation and low speed revolution of cutting tool can be created by one built-in air motor from Novator's mechanism (PCT/SE2008/050719) which needs two driving sources.The purpose of this paper is that by replacing a built-in air motor used in the previous hole making machine with a built-in AC motor it is achieved to lighten the weight of the machine and also to be handy by applying electric control device. After that hole making tests are executed to CFRP/TiAl6V4 stacks by using a new type cemented carbide endmill having 6 blades.

РАЗРАБОТКА СХЕМЫ БАЗЫ ДАННЫХ СПИРАЛЬНЫХ СВЕРЛ И ОСНОВНЫХ ТИПОВ ФРЕЗ

РАЗРАБОТКА СХЕМЫ БАЗЫ ДАННЫХ СПИРАЛЬНЫХ СВЕРЛ И ОСНОВНЫХ ТИПОВ ФРЕЗ

The elimination of coal and gas outburst disasters by ultrathin protective seam drilling combined with stress-relief gas drainage in Xinggong coalfield

The No. 21 coal seam in Xinggong coalfield belongs to all-layer structured soft coal, with poor permeability and high frequency of coal and gas outbursts. Considering the gas geological condition and gas occurrence regularity of the No. 21 coal seam in Xinggong coalfield, an important technology has been developed for the elimination of coal and gas outburst disasters by ultrathin protective seam drilling combined with stress-relief gas drainage. Ultrathin protective seam with thickness of 0.3–0.5 m was drilled using spiral drilling machine in the field, with improved extraction of stress-relief gas of the No. 21 seam. And the changes of roof and floor displacement and coal seam permeability were systematically studied during the drilling process, together with the flow and drainage rules of stress-relief gas of the No. 21 coal seam. The above results show that after the use of ultrathin protective seam drilling combined with stress-relief gas drainage, gas pressure of the No. 21 seam decreased from 1.2 MPa to 0.15 MPa, with the gas content from 16 m3/t to 4.66 m3/t. The permeability of coal seam increased from 0.0012 mD to 0.4732 mD, nearly 400 times. Coal and gas outburst dangers were completely eliminated of the No. 21 coal seam, and the mining with high safety and efficiency of Xinggong coalfield was successfully realized.

Three Edged Drill vs. Double - Edged Drill in Aluminium Parts Drilling

This paper proposes an answer to a question like "it is better to use something new or use what we already know is a relatively recent technique novelty, which is found in tools manufacturer’s catalogues but still very rarely used, almost unknown in current industrial practice: spiral drill with three cutting edges. To give an endorsed answer, it starts machining a concrete case of a part of aluminium and research, based on a minimal experimental program, the processing with new drilling tool compared with the known helical drill. Answer the question initially is not simple, nor one given in few words and none with the high degree of generality, but one nuanced, depending on the performance indicators considered to be of interest and closeness of experimental working conditions than those found in current industrial environment. Helpful for the formulation and presenting the response is the processing of experimental data in the form of calculations, graphs and summary of the rejection’s causes. In this way, the concluding elements stand out more obvious and a number of partial answers can be formulated and justified recommendations can be done regarding: which of drills, where and in which conditions provides the best quality of machined hole, the best chip fragmentation and with the best ratio: price / quality / operation.

Improvement and Application Technology of Long Bedding Borehole Rig in Rockburst Seam at Headentry and Tailentry

Advantages, disadvantages, and drilling adaptability of several rigs earlier used in domestic coal mine are analyzed. CMS1-800/30 crawler jumbo is reconstructed from standing pillar rig according to specific condition of long bedding borehole at coal face which possesses rockburst trend. Wide blade spiral drill pipe and Φ65mm diamond compact bit are used to drill long bedding borehole at headentry and tailentry. Drilling efficiency of long bedding borehole is greatly improved, and effect of relieving stress is very good. Safe and quick mining is ensured, and economic benefit is remarkable.