The Hy-Wire Car
Cars are immensely complicated machines, but when you get down to it, they do an incredibly simple job. Most of the complex stuff in a car is dedicated to turning wheels, which grip the road to pull the car body and passengers along. The steering system tilts the wheels side to side to turn the car, and brake and acceleration systems control the speed of the wheels.
Given that the overall function of a car is so basic (it just needs to provide rotary motion to wheels), it seems a little strange that almost all cars have the same collection of complex devices crammed under the hood and the same general mass of mechanical and hydraulic linkages running throughout. Why do cars necessarily need a steering column, brake and acceleration pedals, a combustion engine, a catalytic converter and the rest of it?
According to many leading automotive engineers, they don't; and more to the point, in the near future, they won't. Most likely, a lot of us will be driving radically different cars within 20 years. And the difference won't just be under the hood -- owning and driving cars will change significantly, too.
In this article, we'll look at one interesting vision of the future, General Motor's remarkable concept car, the Hy-wire. GM may never actually sell the Hy-wire to the public, but it is certainly a good illustration of various ways cars might evolve in the near future.
Two basic elements largely dictate car design today: the internal combustion engine and mechanical and hydraulic linkages. If you've ever looked under the hood of a car, you know an internal combustion engine requires a lot of additional equipment to function correctly. No matter what else they do with a car, designers always have to make room for this equipment. The same goes for mechanical and hydraulic linkages. The basic idea of this system is that the driver maneuvers the various actuators in the car (the wheels, brakes, etc.) more or less directly, by manipulating driving controls connected to those actuators by shafts, gears and hydraulics. In a rack-and-pinion steering system, for example, turning the steering wheel rotates a shaft connected to a pinion gear, which moves a rack gear connected to the car's front wheels. In addition to restricting how the car is built, the linkage concept also dictates how we drive: The steering wheel, pedal and gear-shift system were all designed around the linkage idea
Thermal Barrier Coatings
Thermal Barrier Coatings
Heat engines are based on considering various factors such as durability, performance and efficiency with the objective of minimizing the life cycle cost. For example, the turbine inlet temperature of a gas turbine having advanced air cooling and improved component materials is about 1500oC. Metallic coatings were introduced to sustain these high temperatures. The trend for the most efficient gas turbines is to exploit more recent advances in material and cooling technology by going to engine operating cycles which employ a large fraction of the maximum turbine inlet temperature capability for the entire operating cycle. Thermal Barrier Coatings (TBC) performs the important function of insulating components such as gas turbine and aero engine parts operating at elevated temperatures.
Thermal barrier coatings (TBC) are layer systems deposited on thermally highly loaded metallic components, as for instance in gas turbines. TBC's are characterized by their low thermal conductivity, the coating bearing a large temperature gradient when exposed to heat flow. The most commonly used TBC material is Yttrium Stabilized Zirconia (YSZ), which exhibits resistance to thermal shock and thermal fatigue up to 1150oC. YSZ is generally deposited by plasma spraying and electron beam physical vapour deposition (EBPVD) processes. It can also be deposited by HVOF spraying for applications such as blade tip wear prevention, where the wear resistant properties of this material can also be used. The use of the TBC raises the process temperature and thus increases the efficiency.
Structure Of Thermal Barrier Coatings
Thermal Barrier Coating consists of two layers (duplex structure). The first layer, a metallic one, is called bond coat, whose function is to protect the basic material against oxidation and corrosion. The second layer is an oxide ceramic layer, which is glued or attached by a metallic bond coat to the super alloy. The oxide that is commonly used is Zirconia oxide (ZrO2) and Yttrium oxide (Y2O3). The metallic bond coat is an oxidation/hot corrosion resistant layer. The bond coat is empherically represented as MCrAlY alloy where
M - Metals like Ni, Co or Fe. Y - Reactive metals like Yttrium. CrAl - base metal.
Coatings are well established as an important underpinning technology for the manufacture of aeroengine and industrial turbines. Higher turbine combustion temperatures are desirable for increased engine efficiency and environmental reasons (reduction in pollutant emissions, particularly NOx), but place severe demands on the physical and chemical properties of the basic materials of fabrication.
In this context, MCrAlY coatings (where M = Co, Ni or Co/Ni) are widely applied to first and second stage turbine blades and nozzle guide vanes, where they may be used as corrosion resistant overlays or as bond-coats for use with thermal barrier coatings. In the first and second stage of a gas turbine, metal temperatures may exceed 850Ã‚Â°C, and two predominant corrosion mechanisms have been identified:
Accelerated high temperature oxidation (>950Ã‚Â°C) where reactions between the coating and oxidants in the gaseous phase produce oxides on the coating surface as well as internal penetration of oxides/sulphides within the coating, depending on the level of gas phase contaminants
Type I hot corrosion (850 - 950Ã‚Â°C) where corrosion occurs through reaction with salts deposited from the vapour phase (from impurities in the fuel). Molten sulphates flux the oxide scales, and non-protective scales, extensive internal suplhidation and a depletion zone of scale-forming elements characterize the microstructure.
Thermal shock on interfacial adhesion of thermally conditioned Glass fiber/epoxy composites
Thermal shock on interfacial adhesion of thermally conditioned Glass fiber/epoxy composites
The fiber/matrix adhesion is most likely to control the overall mechanical behavior of fiber-reinforced composites. An interfacial reaction may result in various morphological modifications to polymer matrix microstructure in proximity to the fiber surface. The interactions between fiber and polymer matrix during thermal conditioning and thermal shock are important phenomena.
Thermal stresses were built-up in glass fiber reinforced epoxy composites by up-thermal shock cycles (negative to positive temperature exposure) for different durations and also by down-thermal shock cycles (positive to negative temperature exposure). The concentration of thermal stresses often results in weaker fiber/matrix interface. A degradative effect was observed in both modes for short shock cycles and thereafter, an improvement in shear strength was measured. The effects were shown in two different crosshead speeds during short-beam shear test.
Differential thermal expansion is a prime cause of thermal shock in composite materials. Thermal expansion differences between fiber and matrix can contribute to stresses at the interface [1-5]. A very large thermal expansion mismatch may result in debonding at the fiber/matrix interface and/or a possible matrix cracking due to thermal stress [6-8]. The fiber/matrix interface is likely to affect the overall mechanical behavior of fiber-reinforced composites.
The performance of fiber reinforced composite is often controlled by the adhesion chemistry at the fiber/matrix interface. Thermal expansion coefficients of polymers are substantially greater compared to metals or ceramics. That is why failure of the bond between fiber and resin occurs under the influence of temperature gradient. The common reinforcement for polymer matrix is glass fiber. One of the disadvantages of glass fiber is poor adhesion to matrix resin.
The short beam shear (SBS) test results may reflect the tendency of the bond strength where only the bonding level is a variable . A large number of techniques have been reported for measuring interfacial adhesion in fiber reinforced polymer composites [10-16]. A need probably exists for an assessment of mechanical performance of such composite under the influence of thermal shock.
Thermal stresses caused by temperature gradient should be given special attention in many application areas. A better understanding of interfacial properties and characterization of interfacial adhesion strength can help in evaluating the mechanical behavior of fiber reinforced composite materials.
Total Productive Maintenance
Total Productive Maintenance
Maintenance has a far greater impact on corporate profitability than most managers are willing to consider, much less admit .And, as the competitive environment in the world continues to increase the pace, companies are looking for new strategies to save on costs, develop employees to face future challenges and bring about a new culture at work place. This has become imperative to stay in business and have an edge over the competition. In this situation, a number of strategies like Total Quality Management, Kaizen, quality circles, ISO certification, six sigma and Total productive Maintenance are available and it is the management choice to selectively implement these in their workplace.
What is TPM ?
Seiichi Nakajima (1988) has defined TPM as an innovative approach to maintenance that optimizes equipment effectiveness, eliminates breakdowns, and promotes autonomous maintenance by operators through day-to-day activities involving the total work force. Thus, TPM is not a specific maintenance policy, it is a culture, a philosophy and a new attitude towards maintenance. The salient features of TPM is the involvement of operators in carrying out autonomous maintenance by participating in cleaning, lubrication, minor repair, adjustments etc. The benefits of TPM can be very tangible. There are organizations, which through implementation of TPM have been able to increase the production volume by 50%. Reduce down time by 27% and rate of defective products by 80%. In addition to tangible benefits, TPM also various intangible benefits such as fostering of teamwork, increase morale, safety and nurturing the work force increased intellectual capabilities having the potential of meeting today's level of competition and challenges.
Evolution Of TPM
TPM descends from Japan and came into existence in the seventies. After Dr W Edward Deming made an impact in Japan through his teaching of quality, Japanese organization felt a need for autonomous maintenance and small group activities to support the quality movement. Today thousands of organizations all over the world are implementing TPM and about 100organisations are now doing it in India.
Total productive maintenance (TPM) is a proven strategy for medium to large industries to get superior business results and develop people skills to take on future business Challenges. Unlike ISO certification process, in TPM, focus is on maintaining the equipment and process in perfect condition- to get best quality products and involve all employees in Collectively carrying out loss elimination, using analytical problem solving tools. The fundamental belief is that if the equipment is maintained well and setting is done by a conscious, skilled operator, once can get the best quality product. The whole concept of TPM is built around this belief and hence the name total productive maintenance. However, this concept can be applied to places other than plant and equipment and instead we could name Total productive Management rather than just maintenance.
Welding technology has obtained access virtually to every branch of manufacturing; to name a few bridges, ships, rail road equipments, building constructions, boilers, pressure vessels, pipe lines, automobiles, aircrafts, launch vehicles, and nuclear power plants. Especially in India, welding technology needs constant upgrading, particularly in field of industrial and power generation boilers, high voltage generation equipment and transformers and in nuclear aero-space industry. Computers have already entered the field of welding and the situation today is that the welding engineer who has little or no computer skills will soon be hard-pressed to meet the welding challenges of our technological times. In order for the computer solution to be implemented, educational institutions cannot escape their share of responsibilities.
Automation and robotics are two closely related technologies. In an industrial context, we can define automation as a technology that is concerned with the use of mechanical, electronics and computer-based systems in the operation and control of production. Examples of this technology include transfer lines, mechanized assembly machines, feed back control systems, numerically controlled machine tools, and robots. Accordingly, robotics is a form of industrial automation.
There are three broad classes of industrial automation: fixed automaton, programmable automation, and flexible automation. Fixed automation is used when the volume of production is very high and it is therefore appropriate to design specialized equipment to process the product very efficiently and at high production rates. A good example of fixed automation can be found in the automobile industry, where highly integrated transfer lines consisting of several dozen work stations are used to perform machining operations on engine and transmission components.
The economics of fixed automation are such that the cost of the special equipment can be divided over a large number of units, and resulting unit cost are low relative to alternative methods of production. The risk encountered with fixed automation is this; since the initial investment cost is high, if the volume of production turns out to be lower than anticipated, then the unit costs become greater than anticipated. Another problem in fixed automation is that the equipment is specially designed to produce the one product, and after that products life cycle is finished, the equipment is likely to become obsolete. For products with short life cycle, the use of fixed automation represents a big gamble.
Programmable automation is used when the volume of production is relatively low and there are a variety of products to be made. In this case, the production equipment is designed to be adaptable to variations in product configuration. This adaptability feature is accomplished by operating the equipment under the control of "program" of instructions which has been prepared especially for the given product. The program is read into the production equipment, and the equipment performs the particular sequence of processing operations to make that product. In terms of economics, the cost of programmable equipment can be spread over a large number of products even though the products are different. Because of the programming feature, and the resulting adaptability of the equipment, many different and unique products can be made economically in small batches.
Air powered cars
Air powered cars
Have you been to the gas station this week? Considering that we live in a very mobile society, it's probably safe to assume that you have. While pumping gas, you've undoubtedly noticed how much the price of gas has soared in recent years. Gasoline which has been the main source of fuel for the history of cars, is becoming more and more expensive and impractical (especially from an environmental standpoint). These factors are leading car manufacturers to develop cars fueled by alternative energies. Two hybrid cars took to the road in 2000, and in three or four years fuel-cell-powered cars will roll onto the world's highways.
While gasoline prices in the United States have not yet reached their highest point ($2.66/gallon in 1980), they have climbed steeply in the past two years. In 1999, prices rose by 30 percent, and from December 1999 to October 2000, prices rose an additional 20 percent, according to the U.S. Bureau of Labor Statistics. In Europe, prices are even higher, costing more than $4 in countries like England and the Netherlands. But cost is not the only problem with using gasoline as our primary fuel. It is also damaging to the environment, and since it is not a renewable resource, it will eventually run out. One possible alternative is the air-powered car.
Air powered cars runs on compressed air instead of gasoline. This car is powered by a two cylinder compressed engine. This engine can run either on compressed air alone or act as an IC engine. Compressed air is stored in glass or fiber tanks at a pressure of 4351 psi.
Within the next two years, you could see the first air-powered vehicle motoring through your town. Most likely, it will be the e.Volution car that is being built by Zero Pollution Motors.
The cars have generated a lot of interest in recent years, and the Mexican government has already signed a deal to buy 40,000 e.Volutions to replace gasoline- and diesel-powered taxis in the heavily polluted Mexico City.
These new vehicles incorporate various innovative and novel systems such as storing energy in the form of compressed air, using new materials such as fiberglass to build the car and vegetable oil for the motor lubrication. Numerous innovations have been integrated in the engine design. As an example, there is a patented system of articulated conrods that allow the piston to pause at top dead center. The following graph indicates this movement of the piston in relation to the driving shaft rotation.
The car engine runs on compressed air and incorporates the three laws of thermodynamics.
1. The first law states that energy can neither be destroyed nor be wasted. 2. The second law describes the disorder within substances. The third law defines that only in crystals at 0o k, there is absolute disorder
The objective of the work describe in this paper is to develop an artificial hand aimed at replicating the appearance and performance of the natural hand the ultimate goal of this research is to obtain a complete functional substitution of the natural hand. This means that the artificial hand should be felt by the user as the part of his/her own body (extended physiological proprioception(EPP) ) and it should provide the user with the same functions of natural hand: tactile exploration, grasping , and manipulation ("cybernetic" prosthesis).
Commercially available prosthetic devices, as well as multifunctional hand designs have good (sometimes excellent) reliability and robustness, but their grasping capabilities can be improved. It has been demonstrated the methodologies and knowledge developed for robotic hands can be apologies and knowledge developed for robotic hands can be applied to the domain of prosthetics to augment final performance. The first significant example of an artificial hand designed according to a robotic approach is the Belgrade/USC Hand.
Afterwards, several robotic grippers and articulated hands have been developed, for example the Stanford/JPL hand and the Utah/MIT hand which have achieved excellent results. An accurate description and a comparative analysis of state of the art of artificial hands can be found in. These hands have achieved good performance in mimicking human capabilities, but they are complex devices requiring large controllers and their mass and size are not compatible with the strict requirements of prosthetic hands.
In fact, the artificial hands for prosthetics applications pose challenging specifications and problems, as is usually the case for devices to be used for functional replacement in clinical practice. These problems have forced the development of simple, robust, and reliable commercial prosthetic hands, as the Otto Brock Sensor Hand prostheses which is widely implanted and appreciated by users. The Otto Bock hand has only one degree of freedom(DOF), it can move the fingers at proportional speed from 15-130 mm/s and can generate grip force up to 100 N.
According to analysis of the state of art, the main problems to be solved in order to improve the performance of prosthetic hands are
1) lack of sensory information gives to the amputee;
2) lack of "natural" command interface;
3) limited grasping capabilities;
4) Unnatural movements of fingers during grasping.
In order to solve these problems, we are developing a biomechatronic hand, designed according to mechatronic concepts and intended to replicate as much as possible the architecture and the functional principles of the natural hand.
The first and second problems can be addressed by developing a "natural" interface between the peripheral nervous system (PNS) and the artificial device (i.e., a "natural" neural interface (NI) to record and stimulate the PNS in a selective way. The neural interface is the enabling technology for achieving ENG-based control of the prostheses, i.e., for providing the sensory connection between the artificial hand and the amputee. Sensory feedback can be restored by stimulating in an appropriate way user's afferent nerves after characterization of afferent PNS signals in response to mechanical and proprioceptive stimuli. The "biomechatronic" design process described above is illustrated in the scheme.
Computer Aided Process Planning (CAPP)
Computer Aided Process Planning (CAPP)
Technological advances are reshaping the face of manufacturing, creating paperless manufacturing environments in which computer automated process planning (CAPP) will play a preeminent role. The two reasons for this effect are: Costs are declining, which encourages partnerships between CAD and CAPP developers and access to manufacturing data is becoming easier to accomplish in multivendor environments. This is primarily due to increasing use of LANs; IGES and the like are facilitating transfer of data from one point to another on the network; and relational databases (RDBs) and associated structured query language (SQL) allow distributed data processing and data access. .
With the introduction of computers in design and manufacturing, the process planning part needed to be automated. The shop trained people who were familiar with the details of machining and other processes were gradually retiring and these people would be unavailable in the future to do process planning. An alternative way of accomplishing this function was needed and Computer Aided Process Planning (CAPP) was the alternative. Computer aided process planning was usually considered to be a part of computer aided manufacturing. However computer aided manufacturing was a stand alone system. Infact a synergy results when CAM is combined with CAD to create a CAD/CAM. In such a system CAPP becomes the direct connection between design and manufacturing.
Moreover, the reliable knowledge based computer-aided process planning application MetCAPP software looks for the least costly plan capable of producing the design and continuously generates and evaluates the plans until it is evident that non of the remaining plans will be any better than the best one seen so far. The goal is to find a useful reliable solution to a real manufacturing problem in a safer environment. If alternate plans exist, rating including safer conditions is used to select the best plans
COMPUTER AIDED DESIGN (CAD)
COMPUTER AIDED DESIGN (CAD)
A product must be defined before it can be manufactured. Computer Aided Design involves any type of design activity that makes use of the computer to develop, analyze or modify an engineering design. There are a number of fundamental reasons for implementing a computer aided design system.
a. Increase the productivity of the designer: This is accomplished by helping the designer to visualize the product and its component subassemblies and parts; and by reducing the time required in synthesizing, analyzing, and documenting the design. This productivity improvement translates not only into lower design cost but also into shorter project completion times. b. To improve the quality of the design: A CAD system permits a more thorough engineering analysis and a larger number of design alternatives can be investigated. Design errors are also reduced through the greater accuracy provided by the system. These factors lead to a better design.
c. To improve communications: Use of a CAD system provides better engineering drawings, more standardization in the drawings, better documentation of the design, fewer drawing error, and greater legibility.
d. To create a database for manufacturing: In the process of creating a the documentation for the product design (geometries and dimensions of the product and its components, material specification for components, bill of materials etc), much of the required data base to manufacture the product is also created.
Design usually involves both creative and repetitive tasks. The repetitive tasks within design are very appropriate for computerization.
F1 Track Design and Safety
F1 Track Design and Safety
Success is all about being in the right place at the right time Â¦.. and the axiom is a guiding principle for designers of motorsport circuits. To avoid problems you need know where and when things are likely to go wrong before cars turn a wheel -and anticipating accidents is a science.
Take barriers, for example .there is little point erecting them in the wrong place -but predicting the right place is a black art. The FIA has developed bespoke software, the Circuit and Safety Analysis System (CSAS), to predict problemareas on F1 circuits. Where and when cars leave circuits is due to the complex interaction between their design, the driver's reaction and the specific configuration of the track, and the CSAS allows the input of many variables-lap speeds ,engine power curves, car weight changes, aerodynamic characteristics etc -to predict how cars may leave the circuit at particular places. The variables are complex. The impact point of a car continuing in a straight line at a corner is easy to predict, but if the driver has any remaining control and alters the car's trajectory, or if a mechanical fault introduces fresh variables, its final destination is tricky to model. Modern tyre barriers are built of road tyres with plastic tubes sandwiched between them. The side facing the track is covered with conveyor belting to prevent wheels becoming snagged and distorting the barrier. The whole provides a deformable 'cushion' a principle that has found its way to civilian roads. Barriers made of air filled cells, currently under investigation may be the final answer. Another important safety factor is the road surface. Racing circuits are at the cutting edge of surface technology, experimenting with new materials for optimum performance.
Circuit and Safety Analysis System (CSAS)
Predicting the trajectory and velocity of a racing car when it is driven at the limit within the confines of a racing track, is now the subject of a great deal of analytical work by almost all teams involved in racing at all levels. However, predicting the trajectory and velocity of a car once the driver has lost control of it has not been something the teams have devoted a great deal of time to. This can now also be analyzed though in the same sort of detail, to assess the safety features of the circuits on which it is raced. The two tasks are very different, and the FIA had to start almost from scratch when it set out to develop software for its Circuit and Safety Analysis System (CSAS).
The last two decades have seen a steady build up of the R&D effort going into vehicle dynamics modeling, particularly by those teams that design and develop cars as well as race them. The pace of development has been set by the availability of powerful PC's, the generation of vehicle and component data, and the supply of suitably qualified graduates to carry out the work. Their task is to be able to model and predict the effects of every nuance of aerodynamic, tire, engine, damper etc., characteristic on the speed of their car at every point on a given circuit. The detail in the model will only be limited by available dynamic characteristics and track data, and will require a driver model to complete the picture. However, they are only interested in the performance of the car while the tires are in contact with the tarmac, and the driver is operating them at or below their peaks.
Everyday radios, newspapers, televisions and the internet warn us of energy exhaustion, atmospheric pollution and hostile climatic conditions. After few hundred years of industrial development, we are facing these global problems while at the same time we maintain a high standard of living. The most important problem we are faced with is whether we should continue "developing" or "die".
Coal, petroleum, natural gas, water and nuclear energy are the five main energy sources that have played important roles and have been widely used by human beings.
The United Nations Energy Organization names all of them "elementary energies", as well as "conventional energies". Electricity is merely a "second energy" derived from these sources. At present, the energy consumed all over the world almost completely relies on the supply of the five main energy sources. The consumption of petroleum constitutes approximately 60 percent of energy used from all sources, so it is the major consumer of energy.
Statistics show that, the daily consumption of petroleum all over the world today is 40 million barrels, of which about 50 percent is for automobile use. That is to say, auto petroleum constitutes about 35 percent of the whole petroleum consumption. In accordance with this calculation, daily consumption of petroleum by automobiles all over the world is over two million tonnes. At the same time as these fuels are burnt, poisonous materials such as 500 million tonnes of carbon monoxides (CO), 100 million tonnes of hydrocarbons (HC), 550 million tonnes of carbon ©, 50 million tonnes of nitrogen oxides (NOx) are emitted into the atmosphere every year, severely polluting the atmosphere. At the same time large quantities of carbon dioxide (CO2) gases, resulting from burning, have also taken the major responsibility for the "green house effect".
Atmospheric scientists now believe that carbon dioxide is responsible for about half the total "green house effect". Therefore, automobiles have to be deemed as the major energy consumer and atmosphere's contaminator. Also, this situation is fast growing with more than 50 million vehicles to be produced annually all over the world and place into the market. However, at is estimate that petroleum reserve in the globe will last for only 38 years . The situation is really very grim.
Addressing such problems is what a Green engine does or tries to do. The Green engine as it is named for the time being, is a six phase engine, which has a very low exhaust emission, higher efficiency, low vibrations etc. Apart from these features, is its uniqueness to adapt to any fuel which is also well burnt. Needless to say, if implemented will serve the purpose to a large extent.
Compared to conventional piston engines, operated on four phases, the Green engine is an actual six phase internal combustion engine with much higher expansion ratio. Thus it has six independent or separate working processes: intake, compression, mixing, combustion, power and exhaust, resulting in the high air charge rate. Satisfactory air-fuel mixing, complete burning, high combustion efficiency and full expansion. The most important characteristic is the expansion ratio being much bigger than the compression ratio.
Head And Neck Support (HANS)
Head And Neck Support (HANS)
Only recently has the racing industry acknowledged that the number one cause of racing-related fatalities is basilar skull fractures from excessive head motions and neck loading. Racing legend Dale Earnhardt's death proved to the racing world and the general public that what appears to be a low impact crash can be fatal. Under development and extensively tested for over a decade, there is a device that can reduce the risk of serious injury or even death to the driver in such a crash. It is the Head And Neck Support (HANS) device.
The HANS, head and neck support was invented by Dr. Robert Hubbard, a biomechanical engineering Professor at Michigan State University. Many debilitating or fatal head and neck injuries could be prevented using this system. In 2000, compact versions of HANS (Figure 2) were developed for CART, IRL, F1, NASCAR, NHRA, ASA, Sports cars, Power Boating and many other racing series. Extensive testing has proven that HANS consistently reduces the injury potential from head motions and neck loads.
The latest example of the engineers' efforts to make Grand Prix racing as safe as possible is the new Head And Neck Support (HANS). The system is easy to use and extremely effective. It prevents over-extension of the driver's neck region in the event of extreme deceleration. It is designed to 'complete' driver head protection, covering the one aspect to be still exposed.
Forward movement of the head and neck has, until now, been the only unrestrained area in driver impact safety. Extensive research and testing has resulted in what experts now believe to be a practical solution to the issue.
HANS features a carbon fibre collar connected securely to the upper body, with straps attaching it to the helmet. The four main parts of the system are:
1. Support brace- rests on shoulders.
2. Padding- is 'fine tuned' for both comfort and fit.
3. Tethers-high strength Nomex tethers secure helmet to support brace.
4. Anchoring- complete system is secured by standard 75mm shoulder straps.
The fundamental purpose of the system is to effectively form a single 'body' of the head and torso.
By purposely directing the loads experienced following impact, the driver's helmet is able to assist in dissipating the loads. HANS is intended to prevent driver's head from being thrown forward in an accident, a common 'whiplash' situation which could lead to an over extension of the spinal column.
Hydro Forming uses water pressure to form complex shapes from sheet or tube material. The pressure may go up about 60,000 psi depending on the component.
As the automobile industry strives to make car lighter, stronger and more fuel efficient, it will continue to drive hydro forming applications. Some automobile parts such as structural chassis, instrument panel beam, engine cradles and radiator closures are becoming standard hydro formed parts.
The capability of hydro forming can be more fully used to create complicated parts. Using a single hydro formed item to replace several individual parts eliminate welding or hole punching, simplifies assembly and reduce inventory.
Taking Advantage Of Hydro Forming
When considering hydro forming, companies need to ask whether this technology will make a part cheaper to produce. The real question is whether you can refine the entire manufacturing process to take advantage of hydroforming that is when it really makes. Instead of looking at a single competent to determine whether it can be hydro formed , companied need to look at a product through whole process, from material to assembly , to determine what savings can be achieved . For e.g. Hydro forming often reduces number of pieces or the amount of floor space used or eliminates the need for welding stations.
Methods Of Hydro Forming
Tube Hydro forming
Straight, pre bent and or performed tubes are formed by internal water pressure with additional application of compressive mechanical forces. In this method the tube in placed in die and as press clamps the die valves, low pressure fluid in introduced into tube to pre form it.
One the maximum clamping pressure in achieved, the fluid pressure inside the tube in increased so that tube bulges to take internal shape of the die. Simultaneously additional cylinders axially compress the tube to prevent thinning and brushing swing expansion.
Skid Steer Loader and Multiterrain Loader
Skid Steer Loader and Multiterrain Loader
Skid-steer loaders began catching on in the construction field in the 1980s because they offered contractors a way to automate functions that had previously been performed by manual labor.
Those were small, inexpensive machines that improved labor productivity and reduced work-related injuries. Their small size and maneuverability allows them to operate in tight spaces. Their light weight allows them to be towed behind a full-size pickup truck, and the wide array of work-tools makes them very flexible. They were utility machines, used for odd jobs ranging from work site clean up to small scale digging, lifting, and loading. In most cases, they logged far fewer hours of usage each year than backhoe loaders and wheel loaders, but they were cheap, and so easy to operate that anyone on a job site could deploy them with very little training.
Since then, the category has become wildly popular in all avenues of construction. They are the best-selling type of construction equipment in North America, with annual sales exceeding 50,000 units. They still tend to be low-hour machines, but, thanks to a virtually unlimited variety of attachments, skid-steer loaders can handle a huge array of small-scale jobs, from general earthmoving and material handling to post hole digging and landscaping to pavement milling and demolition.
As the machine has grown in popularity, it has become one of the hottest rental items in North America. Equipment rental houses consume roughly one-third of the new units sold each year, and most stock a wide array of attachments, too. The ready availability of rental attachments - especially high-ticket, specialty items like planers, vibratory rollers, tillers, and snow blowers and pushers - has turned the machines potential for versatility into a cost-effective reality.
As the skid-steer has become more popular in construction, the average size of the machine has grown, too. In the mid-1980s, the most popular operating load class was 900 to 1,350 pounds. By the mid-1990s, the 1,350 to 1,750 pound class was the most popular. Today, the over-1,750-pound classifications are the fastest growing.
Larger machines have dominated new product introductions, too, though our survey of recent new product announcements has turned up a spate of compact and sub-compact introductions, too. The smallest of these are ride-behind models aimed mainly at the consumer rental trade, but they are also used in landscaping and other types of light construction essentially to automate jobs that would otherwise be done by laborers with shovels.
Road contractors and government highway departments should find the new super-duty class of skid-steer loaders especially interesting. These units have retained the skid-steer's traditional simplicity of operation and compact packaging, while also boasting power and weight specifications that let them perform many of the tasks done by backhoe loaders and compact wheel loaders. Nearly all boast high-pressure, high-flow hydraulic systems to run the most sophisticated hydraulic attachments. They also feature substantial break-out force ratings for serious loading and substantial lifting capacities for material handling.
The skid-steer loader represents an interesting alternative for fleets that have low- hour backhoe loaders in inventory. Led by Bobcat, Gehl, Mustang, and other companies that make skid-steers but not backhoe loaders, skid-steer marketers have been pushing the proposition that it is more cost effective to replace a backhoe loader with a skid-steer and a mini-excavator. The rationale: for about the same amount of money, you can get more hours of utilization because you have two machines that can be working simultaneously at different jobs.