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1
Content available The photogrammetric approach in conical picks wear rate evaluation
Krauze Krzysztof, Mucha Kamil, Wydro Tomasz, Pawlik Jan, Wróblewska-Pawlik Aleksandra
Production Engineering Archives
|
2023
|
Vol. 29, Iss. 4
413-420
EN
The cutting tools in mining industry are especially prone to rapid wear, since most of the rocks exhibit aggressive abrasion attributes. A typical representative of fast wearing mining end-tools is a conical pick (also known as tangential-rotary cutter). In order to decrease the premature deterioration, the manufacturers and users tend to enhance the lifespan of the tool by wide range of approaches, namely heat treatment, chemical treatment, burnishing, hard facing etc. In order to estimate the wear rate of a given pick one has to select appropriate procedure and method of evaluation. By this time, most commonly applied method is to estimate the wear rate basing on mass loss measurements of the tools being exploited with constant cutting parameters and fixed conditions. The Authors proposed also a new method of volumetric wear assessment, basing of three-dimensional photogrammetric scanning and compared the results with the outcome of traditional mass wear evaluation of the same sets of tools. Additionally, this paper contains recommendations regarding both approaches (volumetric and mass), especially focusing on the possibilities of the new method concerning measurements of the manufactured tool.
2
Content available Ocena jakości noży styczno-obrotowych oraz prognozowanie ich kosztów zużycia
Krauze Krzysztof, Mucha Kamil, Wydro Tomasz
Przegląd Górniczy
|
2020
|
T. 76, nr 9
1--9
PL
W chwili obecnej wybór, przez użytkownika, noża styczno-obrotowego polega na sprecyzowaniu jego parametrów geometrycznych i materiałowych, uwzględniających miejsce i warunki jego pracy. Następnie dokonuje się wyboru, zazwyczaj na podstawie tylko jednego kryterium, jakim jest cena. Tym samym na etapie zakupu, jak i eksploatacji, nie prowadzi się oceny jakości noży i ich przydatności do konkretnej maszyny i urabianego minerału. Dlatego powstała metoda pozwalająca przeprowadzić takie badania, w których dokonuje się pomiarów parametrów geometrycznych noża, ustala się rodzaje materiałów korpusu noża i wkładki WC oraz szybkość zużycia (intensywność) na stanowisku laboratoryjnym. Szybkość zużycia (intensywność) opisana jest za pomocą wskaźnika C2, którego wartość im jest mniejsza, tym nóż wolniej się zużywa. Wskaźnik C2 został wykorzystany do prognozowania zużycia noży i określenia ich ceny jednostkowej oraz kosztów eksploatacyjnych. Pozwala to na precyzyjne określenie wymagań inwestycyjnych i prawidłowy wybór noża.
EN
Currently, the user’s choice of a conical pick involves specifying its geometric and material parameters, taking into account the place and conditions of its work. The selection is then made, usually on the basis of solely one criterion, which is the price. Thus, at the stage of both purchase and operation, the quality of picks and their suitability for a specific machine and the processed mineral are not assessed. Therefore, a method was developed to enable conducting tests that determine the geometric parameters of a pick, the types of materials of the pick body and WC insert as well as the pick wear rate (intensity) in a laboratory workstation. The wear rate (intensity) is described by the C2 index - the smaller is its value, the slower is the pick’s wear. The C2 index has been used to forecast the wear of picks and to determine their unit price and operating costs. This allows for precise determination of investment requirements and a proper selection of the pick.
3
Content available Conical Picks for Undeground Mining
Bołoz Łukasz
New Trends in Production Engineering
|
2020
|
Vol. 3, Iss. 1
221--230
EN
Mechanical cutting in underground mining faces increasingly difficult challenges. Deteriorating working conditions result in the development of automation and robotization, and the insufficient durability of cutting tools remains a serious problem. In addition to drilling, the technology of cutting provides a huge market for tools. Currently, mainly conical picks are used in the process of cutting. The cutterheads of shearers are equipped with at least several dozen conical picks, which, due to their workability and abrasiveness, sometimes work for merely a few hours. Hence the interest of users and manufacturers in the development of tools with increased durability. The article briefly presents the applied solutions of conical picks, their construction, dimensions and materials used. Attention was paid to the issues related to the protection applied and its marking. A review and analysis of commonly known construction solutions for picks and holders have also been carried out, and proprietary patent pending solutions for the pick and holder have been presented.
4
Content available Conical Pick Production Process
Bołoz Łukasz, Kalukiewicz Antoni, Galecki Greg, Romanyshyn Liubomyr, Romanyshyn Tara, Barrionuevo-Giménez Rafael
New Trends in Production Engineering
|
2020
|
Vol. 3, Iss. 1
231--240
EN
One of the basic methods of mechanical rock mining is cutting, which faces increasingly difficult working conditions. Despite the rapid development of machines used in underground and opencast mining as well as in tunnel building, construction industry and road engineering, the problem of insufficient durability of mining tools remains unsolved. In addition to drilling and, to a lesser extent, planing, cutting provides a huge market for tools. Currently, the process of cutting is mainly based on conical picks. The cutterheads of cutting machines are equipped with several dozen, and frequently – more than one hundred conical picks, which, due to their workability and abrasiveness, sometimes work only a few hours. There is a market demand for over two hundred models of conical picks. This is due to the huge variety of shapes and sizes of picks as well as the methods of their mounting in the holder. The article briefly presents various solutions of conical picks, their construction, methods of protection, dimensions and materials used. Next, based on materials produced by ZWM Carbonex, the classic method of their manufacture using the turning technology has been described. The authors have also presented briefly the use of die forging for the large-scale production of picks, applied by Górnicza Fabryka Narzędzi Sp. z o.o.
5
Content available Evaluation of the Quality of Conical Picks and the Possibility of Predicting the Costs of Their Use
Krauze Krzysztof, Mucha Kamil, Wydro Tomasz
Multidisciplinary Aspects of Production Engineering
|
2020
|
Vol. 3, Iss. 1
491--504
EN
Currently, the user’s choice of a conical pick involves specifying its geometric and material parameters, taking into account the place and conditions of its work. The selection is then made, usually on the basis of solely one criterion, which is the price. Thus, at the stage of both purchase and operation, the quality of picks and their suitability for a specific machine and the processed mineral are not assessed. Therefore, a method was developed to enable conducting tests that determine the geometric parameters of a pick, the types of materials of the pick body and WC insert as well as the pick wear rate (intensity) in a laboratory workstation. The wear rate (intensity) is described by the C2 index – the smaller is its value, the slower is the pick’s wear. The C2 index has been used to forecast the wear of picks and to determine their unit price and operating costs. This allows for precise determination of investment requirements and a proper selection of the pick.
6
Content available Comprehensive tests of sintered carbides in the aspect of conical picks operational life
Grzegorzek Wojciech, Jaszczuk Marek
Mining Science
|
2020
|
Vol. 27
119--131
EN
The results of tests on the brittle fracture and abrasive wear of conical picks sintered carbides taking into account the size of tungsten carbide grains and the content of cobalt are presented. The tests were carried out on the innovative laboratory stand for tribological tests using the method for determination of resistance to edge fracture and abrasive wear. Test results have shown that an increase in the size of tungsten carbide grains, and thus an increase in the cobalt content, reduces the wear resistance and increases the resistance to brittle fracture. The results of the tests of sintered carbides inserts in the aspect of their durability are presented.
7
Content available Ocena jakości noży styczno-obrotowych na potrzeby zamówień publicznych
Bołoz Łukasz
Systemy Wspomagania w Inżynierii Produkcji
|
2019
|
Vol. 8, iss. 1
115--125
PL
W artykule przedstawiono wyniki badań jakości handlowych noży styczno-obrotowych na potrzeby realizacji procedur przetargowych zgodnie z prawem zamówień publicznych w Polsce. Przedstawione badania noży są jednymi z nielicznych, które w praktyce pozwalają na wybór oferty na podstawie obiektywnie wyznaczonych liczbowych wskaźników określających jakość produktu a nie jedynie na podstawie ceny. Dzięki temu zamawiający może decydować jaki udział w ocenie oferty stanowić ma cena a jaki jakość. Wymagane w przetargu parametry geometryczne oraz materiałowe, w przypadku braku spełnienia są podstawą do odrzucenia danej oferty noży. Parametrem liczbowym wpływającym na ocenę końcową oferty jest szybkość zużycia noży. Przedstawiono wyniki badań parametrów geometrycznych, materiałowych oraz szybkości zużycia 48 kompletów noży, przeprowadzone dla przetargu składającego się z 14 zadań. Przetarg przeprowadzono dla 6 kopalni podziemnych jednej ze spółek węglowych. Do wybranych zadań w przetargu swoją ofertę zgłosiło 5 producentów.
EN
The article presents the results of a study on the quality of conical picks for the purposes of tender procedures in accordance with the public procurement law in Poland. The pick studies presented here are one of the few that in practice allow the selection of an offer based on objectively determined numerical indicators defining the quality of the product and not only on the basis of price. Thanks to this, the contracting party can decide the relevance of price and quality in their evaluation of a pick. The geometrical and material parameters required in a tender, if not met, are the basis for rejecting a given offer of picks. The numerical parameter influencing the final evaluation of the offer is the picks' rate of wear. The article presents the results of studies on geometric parameters, material parameters and the rate of wear of 48 sets of picks conducted for a tender consisting of 14 tasks. The tender was conducted for 6 underground mines of a coal company. Five producers submitted their offers for selected tasks in the tender.
8
Content available Sposoby zwiększania trwałości noży styczno-obrotowych
Bołoz Łukasz
Przegląd Górniczy
|
2019
|
T. 75, nr 9
28--34
PL
Noże styczno-obrotowe są to narzędzia skrawające stosowane w wielu branżach, zwłaszcza górniczej, drogowej i budowlanej. Kontakt z urabianą calizną powoduje ich ciągłe zużycie. W artykule omówiono rozwiązania konstrukcyjne noży styczno-obrotowych, ich budowę, wymiary oraz stosowane materiały. Opisano zabiegi techniczne stosowane w celu zwiększenie ich trwałości, jak również regeneracji. Omówiono również autorskie, objęte zgłoszeniem o patent na wynalazek, sposoby wydłużenia czasu pracy noży w trudnych warunkach. Pierwsze z tych rozwiązań dotyczy zapewnienia niezakłóconego ruchu obrotowego noża w uchwycie. Zastrzeżenia patentowe obejmują nowatorskie łożyskowanie obrotowe dodatkowej tulei zintegrowanej z uchwytem, która umożliwia ciągły obrót noża. Uchwyt przeznaczony jest do mocowania klasycznych noży handlowych. Wymiana noża odbywa się bez ingerencji w węzeł łożyskowy. Drugie rozwiązanie dotyczy sposobu zabezpieczenia części roboczej noża za pomocą specjalnego elementu z materiału trudnościeralnego. Element ten stanowi ostrze noża o geometrii odbiegającej od standardowo stosowanych słupków z węglików spiekanych. W rozwiązaniu tym ostrze ma kształt odpowiadający formie zużycia noża styczno-obrotowego, przez co jego stalowy korpus nie zużywa się.
EN
Conical picks are cutting tools used in many branches, in particular in the mining, road construction and building branch. Contact with the excavated face causes their constant wear, which is an unfavourable but unavoidable process. In the article various solutions of conical picks, their construction, dimensions and materials used have been discussed. Technical procedures applied to increase the durability of conical picks and their regeneration as well as methods of extending the life of picks working in difficult conditions have been presented. Two author’s methods of extending the life of picks working in difficult conditions, covered by a patent application, have also been presented. The first solution involves ensuring an uninterrupted rotational movement of the pick in the holder. Patent claims include an innovative method of equipping the additional sleeve integrated with the holder with a rotational bearing, which enables a continuous rotation of the commercial pick. The pick replacement does not require interfering with the bearing assembly. The second solution concerns the manner of protecting the working part of the pick by means of a special element made of an abrasion resisting material. This element is the pick tip, the geometry of which varies from the commonly applied posts made of sintered carbide. In this solution, the tip has a shape corresponding to the form of conical pick’s wear, which causes that its steel body does not wear.
9
Content available The new method for assessing rock abrasivity in terms of wear of conical picks
Mucha Kamil
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
186--194
EN
During the exploitation of mineral raw materials, a cutting tool is an element that is directly in contact with the unmined stone being cut. The most commonly used cutting tools include conical picks. The increasing pressure to reduce mining costs causes an increasing demand for affordable and reliable ways to increase the reliability of mining machines. Abrasive wear is the most common process affecting the wear of shearer picks, hence a good and simple laboratory method for assessing rocks abrasivity is needed. The new method was developed in the aspect of selection of conical picks with appropriate protection of the pick working part, increasing its durability. The method involves the assessment of mass abrasive wear of a standard steel pin and rock sample, and the determination of the abrasivity index Wz of the tested rock, as the ratio of the mass loss of the steel pin to the mass loss of the rock sample. The article presents the procedure of conducting tests, construction of a laboratory test stand and the use of the developed method to assess the abrasivity of gangue rocks occurring in the currently cut tunnel excavations of Polish hard coal mines.
10
Content available Directions for increasing conical picks’ durability
Bołoz Łukasz
New Trends in Production Engineering
|
2019
|
Vol. 2, Iss. 1
277--286
EN
Conical picks are cutting tools used in many branches, in particular in the mining, road construction and building branch. Contact with the excavated face causes their constant wear, which is an unfavorable but unavoidable process. Milling heads of working machines are equipped with several dozen conical picks, and mining in abrasive or hardly accessible rocks can reduce their life to a few hours. It is in the interest of both users and producers to increase their durability, as tools replacement, apart from purchase and logistic costs, results in machine downtimes. In the article various solutions of conical picks, their construction, dimensions and materials used have been discussed. Technical procedures applied to increase the durability of conical picks and their regeneration as well as methods of extending the life of picks working in difficult conditions have been presented. Two author’s methods of extending the life of picks working in difficult conditions, covered by a patent application, have also been presented. The first solution involves ensuring an uninterrupted rotational movement of the pick in the holder. Patent claims include an innovative method of equipping the additional sleeve integrated with the holder with a rotational bearing, which enables a continuous rotation of the pick. The tool equipped with a bearing generates much lower movement resistance than the standard mounting. The holder is designed to mount classic commercial picks. What is important, the pick replacement does not require interfering with the bearing assembly. The second solution concerns the manner of protecting the working part of the pick by means of a special element made of an abrasion resisting material. This element is the pick tip, the geometry of which varies from the commonly applied posts made of sintered carbide. In this solution, the tip has a shape corresponding to the form of conical pick’s wear, which causes that its steel body does not wear. Moreover, there is a possibility of applying a mobile, rotational mounting of the tip to the body.
11
Content available Results of a study on the quality of conical picks for public procurement purposes
Bołoz Ł.
New Trends in Production Engineering
|
2018
|
Vol. 1, Iss. 1
687-693
EN
The article presents the results of a study on the quality of conical picks for the purposes of tender procedures in accordance with the public procurement law in Poland. The pick studies presented here are one of the few that in practice allow the selection of an offer based on objectively determined numerical indicators defining the quality of the product and not only on the basis of price. Thanks to this, the contracting party can decide the relevance of price and quality in their evaluation of a pick. The geometrical and material parameters required in a tender, if not met, are the basis for rejecting a given offer of picks. The numerical parameter influencing the final evaluation of the offer is the picks' rate of wear. Conical picks are tools for mining minerals, rocks, asphalt or concrete. They are used in many industries, especially in mining, construction and road engineering. In difficult working conditions, the durability of knives is limited to as little as several hours. Several dozen picks work on a cutting unit at the same time, and taking into account the price of a knife which oscillates around several dozen euros, significant operating costs are incurred. Therefore, the selection of tools with an optimum price-quality ratio is crucial. The article presents the results of studies on geometric parameters, material parameters and the rate of wear of 48 sets of picks conducted for a tender consisting of 14 tasks. The tender was conducted for 6 underground mines of a coal company. Five producers submitted their offers for selected tasks in the tender.
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