Pneumatic Drill Research Articles

The development of an ultrasonic vibration hand-held pneumatic drill for hole-machining on CFRP composite materials

Carbon fiber reinforced plastic (CFRP) composite materials are widely adopted for manufacturing aircraft. In aircraft assembly process, millions of bolt and rivet holes need to be machined on site, and most of them are drilled by manual operations with hand-held pneumatic drill. It is well known that unstable operations easily are caused in manual operations, which results in serious defects on CFRP materials. These defects drastically reduce fatigue resistance of aircraft. To improve the quality of drilling holes, an ultrasonic vibration hand-held pneumatic drill is developed in this study. The structure of this device was designed, and its vibration mode was analyzed with finite element method. A real ultrasonic vibration hand-held drill was produced and its vibration performance was measured. Drilling experiments on CFRP materials are implemented. The results show that, with the developed hand-held drill device, the shakes of hand decrease by 35–43% and thrust forces decrease by 23%. The defects of matrix resin peel-off and delamination during drilling process are significantly reduced. This study provides a novel equipment for drilling hole on aircraft assembly site.

The use of pneumatic dental drill in osteosynthesis in patients with fractures of the lower jaw

Nowadays the process of bone cutting and drilling is one of the important problems in maxillofacial surgery. Devices with a low power electric motor and an uncontrolled rotation speed of the work tool, as well as expensive devices such as Piezon-Master 400 are used to make holes during osteosynthesis, implantation and bone cutting in maxillofacial surgery. We have developed a special turbine pneumatic dental drill, which, can be an alternative to standard air turbine devices used in clinical practice when working on facial bones.

Analysis impact of construction site vibrations propagated through the ground on a selected residential building and its residents

An analysis of the harmful effects of vibrations generated as a result of works involving construction site equipment and propagated to an adjacent building and its users through the ground was carried out within the scope of this paper. Mechanical vibrations were generated during construction works by a pneumatic drill and a backhoe loader in the north east section of the 2nd line of the Warsaw Metro. The vibrations were assessed pursuant to the requirements specified in the Polish PN-B-02170:2016-12 standard and compared with the standard threshold values. The research methodology, taking into account a description and location of the measurement site and specification of the measurement apparatus, is also presented.

Improvement of drilling cutter design

The article describes the design of drilling cutters most commonly used in coal mines in Russia. The area of their application is given versus the type of a drilling machine and hardness of rocks. The implemented research aimed at finding the causes of failure of drilling cutters shows the types of breakdowns of drilling cutters and their causes. A review of the recommendations and modern engineering solutions on increase in the life of rotary drilling tools is given. Percentages of the cutter failure causes over the period from 2010 to 2014 are presented. The main failure cause of cutters is found to be the blunting of the blades of tungsten-cobalt cutting plates. The studies conducted earlier by the authors of the article indicate the possibility of extending the life of a drilling tool by reinforcing its cutting plates with superhard composite materials. In this connection, the use of composites based on cubic boron nitride has been proposed for creating cutting inserts for drilling cutters. The article also describes the study of rock drilling rates with various cutters mounted on hydraulic and pneumatic drilling machines. The obtained information can be used when planning drilling in coal mines. It is shown that the highest drilling rate can be achieved with hydraulic drilling machines equipped with triple cutters. It is found that with the growth of rock hardness on the scale of Professor M. M. Protodyakonov, reduction in the drilling rate of a hydraulic drilling rig with a three-blade cutter occurs more intensively than with a pneumatic drilling rig with a two-blade cutter. It is revealed that at the rock hardness of 10 on the Protodyakonov scale, drilling rates of different design cutters differ slightly. The study was supported by the President of the Russian Federation, Grant for Young Candidates of Sciences—MK-6689.2018.8.

РАЗРАБОТКА СИСТЕМ КОНТРОЛЯ ВЫСЕВА СЕМЯН ДЛЯ ЗЕРНОВЫХ СЕЯЛОК

The paper discusses technical aspects involved in developing seeding control systems for grain seeders and sowing machines. Construction and technological parameters of seeding control systems are based on the analysis of the available machinery. As a result an operation-performing unit was constructed and tested in field trials. The RatinalRose visual simulation environment was used to design the software of the seeding control system. The environment allowed for interpreting the volume concentration of particles. A procedure for collecting and presenting data was developed. COMPAS com106 puter program was used to create a 3D design of the sensor and measure its parameters, then the sensor case was made using a 3D printer. Field trials involved comparing 2 identical drills under identical conditions. The drill equipped with the seeding control system had better indices of time saving and efficiency (by 22 %). The study results allowed us to develop the software for the seeding control system and determine the optimal design and process parameters of the seeding control sensor for a pneumatic drill in order to reduce clogging in the seed pipes and improve the quality of seed distribution.

Application of pneumatic directional drilling technology for soft-fragmentized coal seam in Qinglong Coal Mine

Application of pneumatic directional drilling technology for soft-fragmentized coal seam in Qinglong Coal Mine

Advanced Geological Prediction Technology Based on Tunnel Face Borehole Drilling

In the process of drilling, the drilling tool contacts with the rock and soil directly. The response information of the drilling tool reflects the mechanical properties of the rock and soil comprehensively. A large amount of geological data hidden in the response information of the drilling tool can be used to analyze and determine the mechanical parameters and spatial distribution of the rock and soil, thus providing an important reference index for the identification of the formation interface and the classification of the surrounding rock. At present, the response information of drilling tools in the field of geotechnical engineering has not been collected, resulting in a great waste of data resources. To make full use of the relevant parameter information in tunnel blasthole drilling, the relationship between the parameters and the quality of surrounding rock is collected and established, and in combination with the geological situation of the face, the level of surrounding rock in front of the face is predicted. The tunnel of Sandu high-speed rail in Guizhou Province is used to conduct research on advance geological prediction technology based on borehole drilling of tunnel face, and the following results are obtained. The drillability of rock is directly related to drilling speed V, vibration acceleration a, and vibration frequency f. Theoretical research on short-distance geological prediction of borehole drilling in tunnel face is completed on this basis. A set of while-drilling monitoring equipment is developed and applied to pneumatic rock drill. While-drilling equipment can collect the real-time data of drilling speed V and vibration acceleration a of the drilling machine. The data is collected based on the analysis of drilling rate V and vibration acceleration a. The quantitative relationship between rock mass level and drilling information is established. Through application in supporting engineering, a standard database of rock antidrilling coefficient of different levels of surrounding rock based on the rock type of quartz sandstone is preliminarily established. This database is better than the geological report of the excavation site.

The Effect of the Distribution Head Tilt and Diffuser Variants on the Evenness of Sowing Rye and Oat Seeds with a Pneumatic Seed Drill

Due to the sustainable development of agriculture machines with large working widths of 4–6 m or even 9–12 m are increasingly often used for agrotechnical operations. The sowing machinery whose working widths are much bigger than the width of the seed box is equipped with a pneumatic system for transporting seeds from the seed box to coulters. One of the structural elements that affect the sowing accuracy in such seed drills is the distribution head with a diffuser. This article is about research on the influence of the distribution head deviation from the vertical position and constructional variants of the diffuser (the number of diffusion rings and the configuration of their position in the diffuser pipe, which is the distance between them) on the accuracy of distribution of a stream of rye and oat seeds (a seed-and-air stream), which differ in physical characteristics. The main elements, i.e., the innovative stream distributor in the head and the diffusion rings were made using an original design and the rapid prototyping method. The research proved that a change of 0–10° in the angle of the distribution head deviation from the vertical position significantly affected the sowing quality of oat seeds only. The position (density) of the diffusion rings in the lower section of the diffuser (near the supply elbow) was the most effective for both oat and rye seeds, where the average values of the coefficient of variation were 5.31% and 4.62%, respectively. The research results can be used to redesign the construction of the diffuser of the seed drill distribution head so as to reduce the resistance of transport of the seed-and-air mixture in order to improve seed sowing evenness.

Новые метод и средство контроля качества работы пневматических высевающих аппаратов точного высева семян

Новые метод и средство контроля качества работы пневматических высевающих аппаратов точного высева семян

A stratigraphic sequence of six thousand years : Preliminary report on the rescue excavation at the site of the former Óbuda Distillery (BUSZESZ)

Árpád period pit houses with a stone oven, Roman period brick graves and public baths, debris from Middle Bronze Age buildings, an Early Bronze Age cemetery, and Late Copper Age clay pit complexes – the thousands of archaeological features that appeared one below the other in a several metres thick stratigraphic sequence, and the nearly thousand boxes of finds are only one side of the coin. The other is represented by the constant roar of the machines, the deafening noise and the dust clouds from the pneumatic drill, the rhythmical sound of the suburban railway, the hubbub of construction workers, and the tight archaeological deadlines. At the site of the former Óbuda Distillery, during the almost three years of test and rescue excavations, we have encountered nearly all known elements of urban archaeology. We also appreciate that, in spite of the difficulties, we were given a unique, extraordinary and perhaps unparalleled opportunity. The site, after all, lies at the edge of the historical cores of the Roman Military Town and medieval Óbuda. The excavation site is noteworthy not only in terms of its vertical but also its horizontal extent. Following the highly informative period of fieldwork, hopefully we can begin the analysis as soon as possible, through which we may understand, step by step, the significance of this special place, where, until now, there lay the stratigraphic sequence of six thousand years of human presence.

Prediction Model of Drilling Performance for Percussive Rock Drilling Tool

This study suggests a method for quantitatively estimating the drilling performance of the down‐the‐hole (DTH) hammer during percussive drilling of rock surfaces. A pneumatic dynamic model of the DTH hammer was developed that considers the mass flow rate relations representing the orifice opening areas of the air tube, the piston, and bit flushing channels. A drill bit motion model was developed to represent the dynamics of a drill bit impacted by a dropped piston and explain the impact stress propagation and rock‐crushing mechanism. The rock‐crushing effect of the drill button bit was measured through a piston drop test. The pneumatic hammer model and drill bit motion model were then combined in a prediction model to determine the impact efficiency according to different rock types (i.e., soft, medium‐hard, and very hard). The drilling efficiency was defined as the input value of the prediction model, which was used to simulate the drilling performance of DTH hammers considering the rock type and dynamic effect of the drill bit. Finally, the simulation results were compared with the results of in situ drilling tests for verification.

Application example of pneumatic drill hammer in engineering

Application example of pneumatic drill hammer in engineering

Providing high speed drilling of boreholes with portable pneumatic rock drills in emergency situations

The existing portable pneumatic rock drills are the most suitable for drilling and blasting operations in emergency situations due to their small mass and mobility. However, their main disadvantage is the low drilling speed due to insufficient feed force, especially when drilling holes vertically down. As a result of the development of a mathematical model of the drilling process by portable perforators, it was proposed to use light feeders while maintaining the total mass, increasing the drilling speed up to 2 times.

Исследование распределения семян пневматическим высевающим аппаратом точного высева

Исследование распределения семян пневматическим высевающим аппаратом точного высева

User-Centred Design and Multi-Actor Approach in Agricultural Innovations – Case: Combi Drill Design

Abstract.The author has shown that modern technologies do not always meet the expectations of farmers, and this may adversely affect the pace of innovation. It has been confirmed that the developers of agricultural equipment do not clearly understand the context of the use of products and identified the need to use a multi-factor approach: therefore, partners possessing specific knowledge in different areas should join efforts in project activities at all stages of innovation. (Research purpose) To prove that a user-centered design and a multi-factor approach in the development of agricultural machinery increase their efficiency and accelerate the introduction of innovations. (Materials and methods) It is shown that Finnish research and development projects of agricultural machinery design involve numerous participants and end users. For example, the seven-metre-wide combi drill ‘Junkkari W700’ was designed by the Finnish manufacturer Junkkari Oy in close cooperation with end-users and researchers. As a result of the innovation process several benefits have been realized. The drill is easy to operate and service. The users appreciate the straight-forward construction and moderate cost of the drill as compared to competing pneumatic drills. The need for hydraulics is minimized and the row spacing and coulter design has been optimized so that economical tractors with moderate drawbar power can be used. The ISOBUS-based control electronics was designed to be fitted either in the existing tractor or, if ISOBUS is missing, with an optional cable-set and terminal. That enables the users to easily integrate the drill in existing machine chains, having either modern or older tractors, without extra tractor investments. Much attention was put on quality, e.g. individual feeders for every coulter give accurate dosage of seed and fertilizer. The prototyping together with end-users and researchers enabled Junkkari to speed up the innovation process. (Results and discussion) Several benefits proved to have been realized. First of all, the drill is easy to operate and service. The users appreciate the straight-forward construction and moderate cost of the drill as compared to competing pneumatic drills. The need for hydraulics is minimized and the row spacing and coulter design has been optimized so that economical tractors with moderate drawbar power can be used. The ISOBUS-based control electronics as well as an optional cable-set and terminal were designed to be fitted either in the existing tractor. That enables the users to easily integrate the drill in existing machine types, having either modern or older tractors, without extra tractor investments. The design quality was approved, e.g. individual feeders for every coulter give accurate metering of seeds and fertilizers. (Conclusions) The author proves that user-centered design and multi-factor approach methodologies have benefits both for the users and manufacturers. Swift innovation process saves resources and minimizes the need for excess iterations in the innovation process.

Geothermal drilling in an Alpine karst aquifer and its impact on downstream springs – A case study from Finkenberg, Tyrol, Austria

A borehole heat exchanger array was installed in an Alpine karst aquifer for the first time in Europe. It is composed of nine 400 m deep boreholes in the dolomitic marble of the Hochstegen Formation. New approaches were developed for this unprecedented application and potential risks were checked throughout the sinking of the initial exploratory wellbore. As Finkenberg is located in a tourist area, drilling operations had to be executed within only a few weeks. Several springs downstream from the drilling site are sources of drinking water and tap water supply. Given that the degree and distribution of the Hochstegen Formation karstification was unknown, a spring monitoring program was mandatory in order to obtain drilling permission from public authorities. A practicable and affordable spring monitoring program including several physical and chemical parameters was developed and implemented to document the potential impact of the drilling activities on the spring water. A temporary and locally limited impact of the drilling works on groundwater quality was detected by turbidity measurements. This paper reports the implementation of geothermal drilling in a karst aquifer with a focus on karstification as well as planning, implementation and the results of the spring monitoring program. Such a program can be recommended for comparable projects or questions, adapting the characteristic parameters to be collected and the measurement intervals in consultation with the relevant authorities. It might also increase the chances of gaining approval for geothermal projects in karst and could enhance public acceptance. Key words: Pneumatic down hole hammer drilling, Borehole heat exchanger, Groundwater monitoring, Turbidity, Hochstegen Formation. Geotermalno vrtanje v alpskem kraskem vodonosniku in njegov vpliv na dolvodne izvire - studija primera Finkenberg, Tirolska, Avstrija V alpskem kraskem vodonosniku je bilo prvic v Evropi vzpostavljeno polje geosond. Vkljucuje devet 400 m globokih vrtin, izvrtanih v dolomitnem marmorju Hochstegenove formacije. Razvili smo nove pristope za to aplikacijo brez primere in potrdili morebitna tveganja v casu potopitve prvotne raziskovalne vrtine. Ker je studijsko obmocje Finkenberg na turisticnem obmocju, je bilo treba opraviti vrtanje v samo nekaj tednih. Vec izvirov od mesta vrtanja so viri oskrbe s pitno vodo. Glede na to, da stopnja in porazdelitev zakraselosti Hochstegenove formacije nista bili znani, je bilo treba za pridobitev dovoljenja za vrtanje nujno opazovati izvire. Da bi dokumentirali vpliv vrtanja na izvirsko vodo, je bilo pri spremljanju izvirov treba upostevati vec fizikalnih in kemijskih parametrov. Zaznali smo obcasen in lokalno omejen vpliv vrtanja na kakovost podzemne vode. V prispevku smo predstavili izvajanje geotermalnega vrtanja v kraskem vodonosniku s poudarkom na identifikaciji zakraselosti ter nacrtovanju ter na izvedbi in spremljanju kakovosti voda na izviru. Tak program se lahko uporabi pri primerljivih projektih ali iskanju odgovorov na podobna vprasanja s prilagojenim programom opazovanih parametrov in intervalov merjenja. Prav tako bi lahko povecal možnosti za pridobitev soglasja za geotermalne projekte na krasu in povecal ozavescenost javnosti. Kljucne besede: vrtanje s pnevmatskim kladivom, geosonda, spremljanje podzemne vode, motnost, Hochstegenova formacija. A borehole heat exchanger array was installed in an Alpinekarst aquifer for the first time in Europe. It is composed of nine400 m deep boreholes in the dolomitic marble of the HochstegenFormation. New approaches were developed for thisunprecedented application and potential risks were checkedthroughout the sinking of the initial exploratory wellbore. AsFinkenberg is located in a tourist area, drilling operations hadto be executed within only a few weeks. Several springs downstreamfrom the drilling site are sources of drinking water andtap water supply. Given that the degree and distribution of theHochstegen Formation karstification was unknown, a springmonitoring program was mandatory in order to obtain drillingpermission from public authorities. A practicable and affordablespring monitoring program including several physical andchemical parameters was developed and implemented to documentthe potential impact of the drilling activities on the springwater. A temporary and locally limited impact of the drillingworks on groundwater quality was detected by turbidity measurements.This paper reports the implementation of geothermaldrilling in a karst aquifer with a focus on karstification aswell as planning, implementation and the results of the springmonitoring program. Such a program can be recommended forcomparable projects or questions, adapting the characteristic

Pneumatic rock drill vs. electric rotary hammer drill: Productivity, vibration, dust, and noise when drilling into concrete

ObjectivesBoth pneumatic rock drills and electric rotary hammer drills are used for drilling large holes (e.g., 10–20 mm diameter) into concrete for structural upgrades to buildings, highways, bridges, and airport tarmacs. However, little is known about the differences in productivity, and exposures to noise, handle vibration, and dust between the two types of drills. The aim of this study was to compare these outcomes with similar mass electric rotary and pneumatic rock drills drilling into concrete block on a test bench system. MethodThree experiments were conducted on a test bench system to compare an electric (8.3 kg) and pneumatic drill (8.6 kg) on (1) noise and handle vibration, (2) respirable silica dust, and (3) drilling productivity. The test bench system repeatedly drilled 19 mm diameter x 100 mm depth holes into cured concrete block while the respective exposure levels were measured following ISO standards. ResultsProductivity levels were similar between the electric and the pneumatic drill (9.09 mm/s vs. 8.69 mm/s ROP; p = 0.15). However, peak noise (LPeak: 117.7 vs. 139.4 dBC; p = 0.001), weighted total handle vibration (ahw: 7.15 vs. 39.14 m/s2; p = 0.002), and respirable silica dust levels (0.55 vs. 22.23 mg/m3; p = 0.003) were significantly lower for the electric than the pneumatic drill. DiscussionWhile there were no differences in drilling productivity between an electric and pneumatic drill of similar mass, there were substantial differences in exposure levels of noise, handle vibration, and respirable silica dust. Structural contractors should switch from pneumatic rock drills to electric rotary hammer drills for structural drilling into concrete in order to reduce worker exposures to the hazards of noise, hand vibration, and silica dust.

Reducing pollutant drift from a pneumatic maize seed drill using exhaust air into the fertilizer system

In recent years, serious environmental issues have resulted from the dispersal of pesticides during maize seeding, especially when performed with pneumatic drills. This phenomenon can be detrimental to insects because the products used to dress maize seeds contain pesticides. In this experiment, the conveying of exhaust air into the fertilizer hoses was tested as a potential solution to reduce the dispersion of seed dust. The use of exhaust air through the fertilizer system created a dust drift reduction of 68%, about 20% lower than dual pipe deflectors (specific devices developed to reduce dust drift). In addition, conveying the exhaust air into the fertilizer system reduced the pressure-level into the seeding element by 5 kPa, but this did not interfere with the seeding quality as the vacuum level (58 kPa) was greater than the minimum value required to perform a good quality maize seeding (40 kPa). The conveying of the exhaust air into the fertilizer system demonstrates how the drift of potentially harmful substances can be reduced during sowing of pesticide-dressed maize seeds using pneumatic drills. In fact, this system showed dust drift mitigation performance similar to devices set up especially for this purpose.

Importance of early adjustment of rotary-percussion drilling tool to mineral mining conditions

The authors discuss the technical and economic criteria for the evaluationof efficient application of rotary-percussion drilling tools. The determinants of efficiency of downhole pneumatic drilling hammers are identified. The authors set conditions of high-velocity hole-making and find maximum indices of long-term performance for downhole pneumatic rotary-percussion drilling tools.

Pneumatically Powered Drilling of Carbon Fibre Composites Using Synthetic Biodegradable Lubricating Oil: An Experimental Study

Carbon fibre composites are a key component of aircraft structures because of their enhanced material properties such as favourable strength to weight ratios when compared to metal alloys. During the assembly process of an aircraft, carbon fibre components are joined to other structures using rivets, bolts, and fasteners, and as part of the joining process, the components will need to be machined or drilled. Unlike metal alloys, composites are sensitive to heat and are vulnerable to internal structural damage from machining tools. They are also susceptible to a reduction in strength when fibres are exposed to moisture. In the machining process, carbon fibre composites may be drilled using oils to lubricate carbide machining tools. In this study, a description of the experimental apparatus is provided along with an investigation to determine the influence synthetic biodegradable lubricating oil has on drill rotational speed, drilling load, and drilling temperature when using a pneumatic drill to machine carbon fibre composite material.