Asansör kılavuz ray bağlantı elemanlarının deneysel gerilme analizi
Elevator guide rail anchor elements experimental stress analysis
Yazar: MEHMET ALTUNTAŞ
Danışman: PROF. DR. CEVAT ERDEM İMRAK
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Makine Mühendisliği Ana Bilim Dalı
Derece: Yüksek Lisans, 2012
Konu: Makine Mühendisliği = Mechanical Engineering
Dizin: Asansör = Elevator ; Asansör kabinleri = Elevator cabins

Özet:
Asansörler, günlük hayatımızda düşey taşımada kullandığımız vazgeçilmez transport araçlarıdır. Son yıllarda da çok katlı binaların artmasıyla asansörlere olan ihtiyaç artmıştır. Yaygın olarak kullanılmaya başlanan bu transport araçlar insan taşımada da kullanıldığı için güvenli sistemlere sahip olmak zorundadır. Bu transport araçlarının en önemli parçaları kılavuz raylar ve bunları birbirine bağlanması sağlayan bağlama elemanlarıdır.Kılavuz raylar birbirlerine bağlantı levhaları ve cıvatalar yardımıyla uç uca eklenmekte ve duvar yüzeyine konsollar aracılığı ile sabitlenmektedir. Konsollar ve raylar arasındaki bağlantı ise ray sabitleme tırnakları ile sağlanmaktadır. Asansörün güvenli çalışmasını sağlamak için kılavuz raylar, kılavuz ray bağlantıları ve tespit yerleri bunları etkileyen yüklere ve kuvvetlere yeterince dayanım göstermelidir.Cıvatalar ve tırnaklar yapıya göre çok küçük ve basit yapılar olarak görünsede yapının birarada durmasını sağlayan çok önemli parçalardır ve bundan dolayı güvenlik açısından bu parçaların standartlara uygun kalitede üretilmelidir.Asansörlerde güvenlik tertibatı devreye girdiğinde raylara dolayısıyla tırnaklara ve cıvatalara binen yükler maksimum düzeye ulaşır. Bu kısa süreli yüklemeler sonucu cıvatalarda ve tırnaklarda oluşan yüksek gerilmeler deformasyonlara hatta kopmalara neden olabilir. Bilindiği gibi böyle durumlarda en büyük hasar en küçük ve önemsiz olarak düşülen parçalarda meydana gelir.Literatürde kılavuz raylarla ve konsollarıyla alakalı olarak çalışmalar olduğu halde bu rayları birarada tutan ve onlarla aynı yüklere maruz kalan tırnaklar ve cıvatalar hakkında çalışma mevcut değildir.Bu çalışmada kılavuz ray bağlantı elemanı olarak kullanılan cıvataların ve tırnakların mekanik özelliklerini incelemek için çekme ve kesme deneyi yapılmıştır. Deneyin yapılabilmesi için BS A 305 - ISO 7961 standartlarından yararlanılarak çeşitli aparat tasarımları düşünüldü. Ayrıca aparatlar çekme deneyi yapılacak makinenin çenelerine uygun olacak şekilde tasarlandı. Daha sonra, düşünülen aparatlar bilgisayar ortamında tasarlandı ve imal edildi. Çekme ve kesme deneyleri değişik çaplardaki cıvatalarla ve tırnaklarla yapılmıştır.Deneylerde, cıvatalar ve tırnaklar kopma noktalarına kadar yüklenmiştir. Deneylerden elde edilen sonuçların yanı sıra karşılaştırma yapabilmek için cıvataların ve tırnakların gerilmelerinin matematiksel hesapları yapılmıştır. İki taraftan her deney için gelen sonuçlar karşılaştırılmış ve yorumlanmıştır.

Abstract:
Elevators are indispensable transportation vehicles which we use vertical transport in our daily life. In recent years, increasing the multi-storied buildings increases need for elevators. We use it for people, cargo, goods tranpotation and so it has widespread applications. With incresing elevators, elevator safety issues considerably come into prominence. Because elevators are mostly used for human transportation.Primitive elevators which were operated by human, animal and water power were used in as early as the 3rd century BC. From about the middle of the 19th century, elevators worked with help of steam engine and were used for conveying goods in factories, mines, warehouses. In 1823, two architects who are called Burton and Hormer built an elevator which was ?ascending room? as they were called it. This crude elevator was used for lifting tourists to a platform for a panorama view of London. In 1835, architects Frost and Stutt built an elevator which was called ?Teagle?, a belt-driven, counter-weighted and steam-driven elevator was developed in England.In 1853, American inventor Elisha Otis developed hoist which was equipped with safety device to prevent falling. In 1853, Elisha Otis started to manufacture elevators and patented) a steam elevator in 1861. Actually, he did not invent first elevator he invent a brake system which was used in modern elevator firstly. Finally, Electric elevators came into to use toward the end of the 19th century. The first one was built by the German inventor Werner von Siemens in 1880. And then with passing the electrical system, development of elevator system speed up.Elevator systems consist of many parts and safety factor come into prominence for these parts when people transport from one place to another place. Guide rails which take place in structure of elevator and defination of elevator are the most important element for safety of elevator systems. Guide rails are single element which has own standart. Guide rails guide the counterweight and car in vertical movement seperately , minimize horizontal movement, stop the car in case of working the parachute system, protect the vertical direction of the counterweight and car and are used to prevent to rotate. At the same time, elements of parachute system which are used to keep car are on the guide rails. And so guide rails are vital element for elevator systems.Guide rails attach together end to end with aid of the fishplates and bolts, and are anchored to wall with brackets. Connections between guide rails and brackets are provided by clips. To provide the safe operation of the elevator, guide rails, fishplates, brackets, bolts, clips have enough strenght against to loads and forces which affect these elements. And because of these elements which we use should be manufactured according to the standarts.In here, as we saw, working security of elevator is vital because of transporting people. And so every elements which we use are very important. All of elements have high strenght and high factor of safety. In literature,although there are some defination of guide rails and brackets, there are no study about bolts and clips which keep together and sustain same loads these guide rails.In this study, tensile and shear tests are performed to examine mechanical properties of bolts and clips which are used guide rail anchor element. Various equipment designs are thought with utilizing from standart BS A 305 to perform the experiment. In addition to this, tensile testing equipments are designed to be appropriate for machine?s gribbes. And then equipments which are thought is designed in computer and manufactured. Tensile and shear tests are performed with bolts and clips which are different diameter. In experiments, bolts and clips are loaded until fracture points. Besides, the results which are gained from experiments to compare stress calculations of bolts and clips. The results which are gained from stress calculations and experiments are compared and interpreted.At the beginning of everything, we researched this topic and found some working about bolts, but these were not made for elevetor litereture. And there is no investigation and experiment about clips. This is a very big emptiness for elevator literature. And then we searched patent for two topics and found some patent for bolts, but there is no patent or referans about tensile or shear testing about clips. We take the British Standart for bolt about tensile and shear testing system and then we decided to use it for clips. Because clips seem to be bolts so their behavior are same. From there, started our study for experiment.In the first part, we search some knowledge about elevtor and components. Since ancient times, we had been using the elevator system and with increasing the highrise building, elevator start to be requisite thing for people life. This part we give some information about elevator classification and to consist of many components.In the second part, we research the guide rail in detail, because guide rails are the most important components for elevators and bolts and clips which we investigate are on guide rails. Guide rails must have strong structure, because it bears all the loads and forces of elevator. In this part, we search the types of guide rails and according to the processing there are two types guide rails which we have. They are called call-drawn and machined guide rails. And then shown the materials of guide rails and its characteristics. Found some standarts about it, and they have many processing and their processings are sensitive. Besides this, given the physical attributes and dimansions tables of the guide rails.In this part in addition, given some information about fishplates and then passed from here to clips and bolts. Because bolts which are used on the fishplates are as important as others which are used on the guide rails brackets. Because they are sustained same forces and loads at the guide rails brackets. And then given how to anchor the guide rails brackets for wall. It is important for loads and forces, because according to this, forces and moments changes. In here, bolts occupy important place, because this small parts bears on all loads and forces of elevator.In the third part, research the bolts and clips in detail. Firstly, start the bolts and given some informations about history of the bolts. And realise that, for many years, people use it. Archimedes studied this topics and developed various principles about water screw. Screw threads and metric screws standardized 18th and 19th centuries. In this part in addition, description of bolts and part of bolts are shown and materials of bolts are given. An then class of strenght are investigated and it is very important part, because in here, there are affecting factors of fracture of bolts. At the standart, observed how to encode class of bolts on the bolt head. Fracture points are gained from this code. Then investigated how to manufacture the bolts and almost bolts passing ten stages to finish. These stages are shown in detail. And then types of bolts are shown. In here, as we saw, bolts are diversified according to their heads.In here, in addition to this, informations about clips are given. Three types of clips extensively in market. Clips have different structure and dimensions, according to the bolts. They are manufactured with aid of the casting, because they have complicated structure. In market, there are five types clips and they are encoded T1,T2,T3,T4,T5, but first letter T can change according to the company.In the fourth part, mentioned how to design the equipments, the calculations and preparing the experiments.Firstly, according to standart TS EN 81-1, calculated guide rails stress. While calculated different types loads are used. In here, gained some results for three axes and Z axis is the most loaded axis among the three axes. And from here, understood that mostly shear stress occupied.Secondly, equipments are designed according to the standart and machine. For tensile experiment in standart, shown to make between two plates. In here, plates thicknesses are very important, because these plates should not bend or be deformed. To provide that, thickness of plates should be at half of diameter of bolts or clips at least. And plates material should be bigger than 43 HRC. Thinking machining, equipments are designed cylindrical. Besides this, heads of equipments are designed according to the gribbes of machine. And, part where bolts and clips are fixed is designed channel-shaped. Furthermore, designing of equipments are easy, because equipments are symmetrical.Thirdly, for shear experiment in standart, three parts are designed. And then shear experiments are made with pressing and this changed the structure. For this experiment, thicker materials are used. Equipment consist of three parts. From these parts bottom and upper parts are manufactured single. But connector, for 12mm and 16mm, one each are manufactured.Plates material should be 60-62 HRC at least.Fourtly, fracture points of bolts and clips are calculated. Tensile stress calculation is simple because fracture strenght is known but shear fracture strenght is not known and various coefficients are used to approach.Fifthly, load speed of experiment is taken from standart. And five experiments are performed for every dimensions of bolts and clips. Forces and strokes are taken from computer to compare with calculeted results. And gained reults from computer compared with results which are calculated according to the TS EN 81-1.Besides this, all of the ezperiments are recorded by camera.