Bullet train adopts duck bill
By Dennis Normile, Contributing Editor
Tokyo-Introduced in 1964, Japan's high-speed intercity train came to be known in English as the Bullet Train, thanks to the distinctive bullet-like nose of the first generation of trains. Known officially as the Shinkansen, which roughly translates as New Trunk Line, the trains have evolved over time but always tended to keep a more or less bullet-like nose. However, for the latest, and fastest, generation of Shinkansen, engineers started with a clean slate and ended up with a radical change to the nose of one of Japan's national symbols. The new 700 Series Shinkansen, which began running this spring at speeds of up to 180 mph between Tokyo and Fukuoka, on the westernmost main island of Kyushu, has a wide, flat nose that resembles a duck bill.
| To reduce bogie vibration, a microcomputer senses the degree of vibration and adjusts the force between bogie and car body accordingly.
The shape resulted from extensive computer simulation and wind tunnel testing of various shapes carried out by engineers for Central Japan Railway Company and West Japan Railway Company, the two train operators, with the cooperation of three rolling stock manufacturers--Kawasaki Heavy Industries Ltd., Hitachi Ltd., and Nippon Sharyo Ltd. The objective was to minimize the pressure waves formed ahead of and behind the fast-moving train to reduce air turbulence and cut the resulting drag, vibration, and noise.
Engineers found they could minimize the waves by increasing the size of the train at a constant rate from the very tip of the nose to the point at which the car reaches full size. Or, in simpler terms, a constant rate of change in cross-sectional area minimizes turbulence. Designers found it easier to achieve this constant rate of change in area with a duck's bill rather than with a bullet nose.
The nose job was just one of a number of minor improvements intended to make train operation more efficient and the ride smoother. For noise reduction, the cars have a double-skin structure in which a lightweight aluminum alloy is formed in an extrusion molding process. Nippon Light Metal Co., Sumitomo Light Metal Industries Ltd., and Kobe Steel Ltd. supply the extruded double-skin aluminum.
Cutting drag, noise, and vibration was extended to the pantograph, where a single arm supports the pantograph shoe, instead of the two arms used previously. The pantograph insulators also received aerodynamic covers. To ensure that the use of a single arm would not affect current collection, wind tunnel testing was carried out on full-scale models of the pantograph and the insulator housing.
A further effort to ensure a smooth ride comes from the introduction of a semi-active control system to reduce car sway. A sensor measuring the force of side-to-side acceleration attaches to the underside of the carriage floor. The signal is sent to a control device that adjusts the oil damper to four degrees of stiffness by controlling the opening diameters of three orifices within the damper. Kayaba Industry Co. supplies the dampers. Rion Electro Corp. makes the sensors.
Thanks to the nose job and other drag-reducing measures, including slight overall weight cuts in the cars, the Series 700 runs on 10% less power than previous Shinkansen.
Punctured tires run flat
By Roy O'Connor, Contributing Editor
Hanover, Germany-Continental AG's ContiSafetyRing (CSR) is for new vehicles as well as retrofit applications. A light metal ring with flexible support mounts on the rim, it enables the vehicle to drive on, even when air pressure is lost. The ring supports the tire to maintain maneuverability regardless of a sudden or slow pressure loss. This system allows motorists to continue for about 124 miles at speeds to 50 mph.
| New CSR enables the vehicle to drive another 124 miles after a puncture. The tire rests on a metal ring which has a flexible support, dispensing with the need
for a new rim.
| The ContiWheelSystem (CWS) replaces the steel cored tire bead to reduce tire weight and rolling resistance while enhancing ride comfort.
When the tire runs flat, the CSR alerts the driver with light vibrations and louder operation. The CSR is easy to fit and can be installed at the next tire change.
In a further development intended for new cars, Continental has designed a new tire/rim combination called the ContiWheelSystem, or CWS. The company claims it makes the spare wheel superfluous. For this design, the tire is lined with an outer chamber in the rim and fastened with a rubber filler ring. As a result, the tire can no longer become detached from the rim, even when deflated. When the tire loses pressure, an extra supporting element made of rubber and textile reinforcing materials takes the wheel load. This support is permanently connected to the wheel rim and is not removed or renewed during a tire change.
Andreas Esser, head of Business Fields Original Equipment Continental, believes that "spare wheels will soon be a thing of the past. Run-flat tire designs are becoming evermore safer, reliable, and affordable."
Chandra opens its eyes
By Rick DeMeis, Senior Editor
Cambridge, MA-Launched in July, the Chandra x-ray telescope is the latest of NASA's Great Observatories (see Design News 2/2/98, p. 66). Already, in just the telescope's checkout and calibration phase prior to extensive observations, the instrument is returning useful and spectacular views.
"We are astounded by these images," says Harvey Tananbaum, director of the Smithsonian Astrophysical Observatory's Chandra X-ray Observatory Center. He is referring to the first images received showing the remnants of the supernova Cassiopeia A, which exploded 320 years ago and was observed at the time from Earth. The images are detailed enough that they may indicate the collapsed neutron star or black hole at its center. The pictures also show material blasted out from the explosion crashing into surrounding matter at 10 million miles an hour, causing violent shock waves that generate the x-rays visible to Chandra. Resolution is of such high quality with the telescope, that when trained on what was thought to be a pin-point target quasar, it revealed the object to have an x-ray emitting jet 200,000 light years long.
Chandra was named after the late Nobel laureate Subrahmanyan Chandrasekhar. TRW (Redondo Beach, CA) is the prime contractor for the spacecraft.
By Charles J. Murray, Senior Regional Editor
Marysville, OH-For seismic exploration, giant vehicles known as vibrators provide the ground-pounding force by employing variable volume pumps and hydraulic strokers from Denison Hydraulics. The 25-ton vehicles, designed and built by Input/Output, Inc., Stafford, TX, produce 60,000 pounds of output force. Using hydraulics to send sound waves through the earth, engineers can map subsurface contours and identify likely petroleum sites.
New options for medical implants
By David J. Bak, International Editor
Lancashire, UK-Global availability of a biocompatible thermoplastic, said to be good for long-term medical implants, brings new possibilities to the health care industry. PEEK-OPTIMA LT, the newest member of the Victrix® PEEK™ polymer family of polyaryletherketone resins, offers several design advantages over glass, stainless steel, or titanium, as well as HDPE, Acetal, and Nylon. These include:
Stiff: PEEK polymer is twice as stiff as most engineering plastics with a flexural moduli ranging from 580 to 2,930 ksi.
| PEEK-OPTIMA LT polymer opens a wide range of implant possibilities to in-vivo medical designers.
The latter, says Kevin Jennings, Victrex marketing manager, is especially important in hip implants. Of particular interest, Jennings adds, is the capability to match the stiffness and impact performance of PEEK-OPTIMA LT with that of human bone via custom reinforcements. This allows the polymer implant to function in concert with surrounding skeletal structure.
PEEK-OPTIMA LT polymer can be manufactured into intricate designs and is easily processed into components ranging from micro-thin membranes such as heart valve components to injection moldings and extrusions in excess of 7.5 cm thick. Radiotranslucency, furthermore, permits complete implant inspection via X-ray and CT-scanning.
| PEEK polymer’s success with industrial applications such as bushing and wear surfaces for high-speed cutting tools, pumps, and gears translates to medical implant products.
Victrex claims complete material pedigree traceability and a "No Change" manufacturing guarantee for the new polymer. Potential applications: implants for the hip, knee, spine; dental prosthetics; and pacemaker components.
Medical materials of note
The Medical Design and Manufacturing Show in New York City, June '99, proved a good forum for the announcement of new medical grade materials. Sponsored by Cannon Communications, the annual show covers new product announcements critical to medical equipment design. These and the materials listed below were also be on display at Cannon's MedTech Show in Amsterdam, The Netherlands, September 21 to 23.
Vapor transmitter, viral barrier. Wound care, surgical gowns or drapes, and transdermal patches stand to benefit from an experimental polyurethane elastomer dubbed XUS63153. Developed by Dow Plastics, the new elastomer targets those applications that require high moisture vapor transmission coupled with a viral/bacterial barrier. It can be converted as blown film, cast film, and as extrusion or solution coating. As part of Dow's Pellethane™ thermoplastic polyurethane elastomer family, XUS63153 also offers high clarity, hydrolytic stability, tension and tear strength, abrasion resistance, and resistance to hydrocarbons and chemicals.
Lipid-resistant resin. Bayer Corp. announced a new name for what it claims as the world's first increased lipid-resistant polycarbonate material. Initially introduced in 1997 under the developmental name Makrolon® DPI-1805, the polycarbonate resin will now be referred to by its more commercial name: Makrolon® Rx-1805. The highly transparent material bonds easily with PVC tubing and helps alleviate cracking in high-stress medical device applications where there is contact with intravenous fluid products--particularly lipid emulsions. Less expensive than specialty polyurethane, polyetherimide, and polysulfone materials, the resin has been applied to tubing connectors, and stopcocks.
Thin foams. Thin versions of several standard PORON® urethane foam materials from Rogers Corp. meet stringent low outgassing and anti-fogging criteria, making them ideal for lens gaskets, bezel and instrument housing seals, and for components that protect equipment from breakage. They offer good resistance to ozone, UV light, and other environmental stressors and chemicals. Many versions meet UL ratings, including the UL-JMST2 Component-Gasket material rating, increasingly used by OEMs to specify gasket materials for electrical and electronic equipment. Some thin versions of standard PORON urethane foams are available with an integral (2 mil) PET film for support, which provides additional stability during the fabrication of close tolerance parts and remains with the component to ease assembly of the finished product.
Flame-resistant sponge. Rogers Corp. also displayed its PORON HT-800 silicone sponge materials, recognized by Underwriters Laboratories to meet requirements of the stringent UL94 V-O and 94HF-1 flame classifications. The PORON HT-800 line is characterized by temperature tolerance, allowing its use in sterilization processes and equipment. Even in harsh environments, the material maintains its resistance to compression set, as well as its sealability. High-temperature autoclave sterilization will not affect the silicone foams. Available in a wide range of thicknesses and firmnesses, PORON HT-800 silicone sponges are good for bezel gaskets for protecting electronic displays.
CAD/CAM news and updates
New versions, interfaces, and partnerships
By Katherine Tyrka, Contributing Editor
Paris-Following the launch of Pro/ENGINEER 2000i, Parametric Technology has now added Pro/MECHANICA 2000i to the PTC i-Series mechanical design automation suite. As with Pro/ENGINEER 2000i, Pro/MECHANICA offers a new Windows-based user interface, plus feature-based parametric modeling capabilities and support for Internet accessibility. Pro/MECHANICA 2000i also includes integrated design analysis.
Unigraphics Solutions' Parasolid V11 is now shipping. Key innovations include support for new parallel algorithms to deliver performance gains on SMP workstations, advances in core geometric modeling operations, and a new Parasolid Web Update Service. The Web Update Service allows customers to download Parasolid update packs directly from the site. Unigraphics Solutions has also launched Solid Edge V7, offering a new tubing design module called XpresRoute, plastics and sheet metal enhancements, and more than 250 other improvements.
Following the launch of a native Windows version of ME10 9.0 (CoCreate's 2D mechanical CAD application), and SolidDesigner 7.0, the company has also announced major development plans to extend OneSpace. CoCreate is developing a complete suite of OneSpace applications, due for a phased release during 2000. The applications will offer improvements to allow users to collaborate in real time via the Internet using native models from major CAD applications or in STEP and IGES formats, along with 2D data and text. Finally, CoCreate has launched Design Management, a module to assist ME10 and SolidDesigner users in managing 2D plans, 3D models, and assemblies.
Machine simulation. Spring Technologies has launched a new version of its machining simulation application for 2.5-to 5-axis milling. NCSIMUL V6.2 offers automatic creation of tool geometry either from decoding the NC program or directly from the CAD profile. The company has also recently launched ODM2, a PDM application using Oracle, Sybase, or SQLserver databases as well as Catiancs, an interface that allows users to import Catia models directly into NCSIMUL.
Both SDRC and CoCreate have announced interfaces to Pro/INTRALINK from Parametric Technology. SDRC's interface developed by Altair for the company's Metaphase Enterprise product data management software, and CoCreate's interface for WorkManager now allow users of these applications to access product change data from Pro/ENGINEER applications. CoCreate has also announced the development of an interface for Unigraphics, which should be available by the end of 1999.
Parametric Technology has announced partnerships with both Tecnomatix and CGTech. The Tecnomatix agreement is based on the integration of PTC's Windchill, the company's web-based PDM application, into Tecnomatix's Digital Factory, a PIM (product information management) application…The agreement with CGTech, a market leader in numerical control simulation and verification, will extend Pro/NC functionality with three new options based on CGTech's Vericut product line. addition, PTC has announced Vericut for Pro/ENGINEER, which will replace Pro/NC-Check, offering advanced features such as part rotation and multi-window display.
Other interfaces. Dassault Systemes will integrate SmarTeam into the next CATIA V5 release. Designed for the SME market, SmarTeam is the flagship Windows and web-centric product of Smart Solutions, recently acquired by Dassault Systemes…Camnetics Inc. has released GearTrax 99, an add-on drive component modeling software for SolidWorks 98Plus and beyond. Version 99 adds worm gear modeling to the existing features of spur/helical gears, bevel gears, chain sprockets, timing belt pulleys and belt pulleys.
Algor Inc. has introduced InCAD-plus technology that enables engineers to transfer solid model data seamlessly from Pro/ENGINEER Release 20 software for Windows NT workstations. InCAD-plus has an interface that connects Algor's entire range of finite element analysis (FEA) capabilities, including advanced Mechanical Event Simulation, directly to Pro/ENGINEER software from Parametric Technology Corp.
CATIA V4 release 2.0 now includes the CATIA AP203 STEP Interface, which has ISO 10303 (STEP) certification. SDRC has announced the MetaSTEP interface, which uses STEP guidelines for data interchange between CAD, PDM, and ERP systems.
Opening up their knowledge base to the world, think3 is offering a web-based customer care program. Accessible from the company web site at www.thinkthree.com, the program offers password-free technical articles, bug reports, and workarounds--all in easy-to-view multimedia formats.
Catia Version 5 Release 2 launched two ways
Catia Version 5 Release 2 is now available, and on two scalable middleware platforms designated as P1 and P2. With these two different platforms, Dassault Systemes is now offering Catia to both large companies with advanced design engineering needs, and to small and mid-sized businesses.
Catia P1 provides core modeling for small and mid-sized process-centric users, particularly useful to companies that are suppliers to other Catia-based companies and for companies who want to grow towards large-scale digital product definition. Available for Windows 95, 98, NT, and UNIX operating systems, the new release includes sixteen new products. Highlights include Interactive Drafting, Sheetmetal Design, Wireframe and Surface, Generative Shape Design, and a Catia Team PDM product for management of engineering data at the departmental or project level. Both P1 and P2 products are built on a common V5 architecture for seamless file exchanges.
Catia P2, for users who require advanced design engineering and Product, Process, and Resource modeling, includes 25 products, four of which are new for this release, and enhancements for existing products. Catia P2's extended set of solutions is based on knowledge engineering and hybrid modeling technology. The new release includes generative assembly structural analysis for stress or vibration behavior of assemblies at the design stage, and a new circuit board design product, to design circuit board assemblies in a mechanical design context.
Single-piece bus hails composites
By Norman Bartlett, Contributing Editor
Anniston, AL-Sides, roof, floor, and integral chassis are all one piece in the new CompoBus, launched by the North American Bus Industry (NABI). Key to CompoBus construction: a proprietary technique involving resin transfer under high vacuum. Called the Seeman Composite Resin Infusion Molding Process (SCRIMP), it is named after inventor Bill Seeman and licensed from TPI Composites (Warren, RI).
NABI's Model 40C-LFW CompoBus started life on its designer's computer screens under Pro-ENGINEER Advanced Designer CAD software. This provides both fast and accurate configuration design but also includes structural analysis of the design as it progresses. Finite element model methodologies were used to confirm the design's ability to withstand the stresses of bus operation.
The CAD system provides sizing of glass fiber laminate sections used as the first stage of the composite lay up. SCRIMP also permits other pre-formed parts to be included in the lay up such as local and secondary reinforcement stringers and formers. Metal mounting plates can be bonded onto or molded into parts.
Once the lay up is put under vacuum, the SCRIMP resin distribution system wets out laminates completely; any air between the glass fibers is driven out as the polyvinyl resin infuses the laminate. Standard tests from the ASTM (American Society for Testing and Materials) have shown the void content to be so low as to be undetectable.
The resulting structure comprises composite of consistent quality with about 70% fiber content and 30% resin. In many composites formed in conventional ways, these proportions are reversed. One benefit of low resin content is a high resistance to fire. In addition, the material exhibits high tensile strength and impact properties.
CompoBus's body shell accepts a rear-mounted power plant--Cummins or Detroit Diesel--using either diesel or natural gas fuel. An Allison or ZF transmission is specified, and Meritor axles complete the drive line. Predicted performance with this arrangement is superior to a bus with conventional body because of the reduction in weight. Less powerful engines can be used, thus reducing emissions.
Body shells can be furnished to meet operator requirements including as many as 40 passenger seats. Repair of small collision damage is easy; the damaged area is simply cut out and a replacement section bonded in place using hand lay up techniques.
Although the price of the body will initially be 20% more expensive than a metal equivalent, total life costs are expected to be more attractive. With much better fuel consumption and no corrosion problems, total operating costs are expected to be about 25% lower. First deliveries to American operators will take place in 2000. The price premium should decline as volume builds. The SCRIMP license permits sales to European operators but these are not expected until later.
Tight integration reduces lift-arm cost and complexity
Kansas City, MO-Engineers ask for a tight link between design and analysis, and vendors say they supply it--but when the pedal meets the metal, there is often another story to tell. However, with a little ingenuity, engineers can develop strategies to create this relationship, resulting in a better product.
The engineering consulting firm Intersecting Technology & Design Associates (ITD) knows this well. John Deere (Ankeny, IA) hired ITD to redesign a lift arm on a cotton-harvesting machine. John Deere's goal: lower production cost and reduce weight on a high-volume part.
A cotton harvester has two lift arms, one on either side of the machine. They connect the main frame of the machine to the lift frames, where the picking units are mounted. The arms and frames are cantilevered to one side and must resist twisting during operation.
To reduce production cost, the existing lift arm, a steel weldment consisting of 29 pieces and three subassemblies, was replaced with a single-piece, nodular iron casting for minimal machining. ITD engineers designed the part to be symmetrical so that a single pattern with movable inserts could be used to make the right and left hand parts. This also helped reduce tooling costs.
Throughout the short four-month development process, ITD communicated designs between John Deere and Voss Pattern Co. (Davenport, IA), the pattern maker, to ensure manufacturability. The result was a new lift arm that weighs 90 pounds less than its predecessor.
ITD used Pro/ENGINEER and Pro/MECHANICA from Parametric Technologies Corp. (Waltham, MA). To achieve a good integration, Bird suggests two key elements: "First, follow good Pro/ENGINEER modeling practices," he says. This includes creating features in a logical order where finish features such as rounds and chamfers are pushed as far down on the model tree as possible; and the use of user-defined, copy, or pattern features rather than repeated features to create explicit relationships between similar features.
The second involves meshing the part incrementally as it is being built. This way, when a model doesn't mesh, it requires only a few hours of work to interrogate the problem. If you wait until the model is completed, "you would have no idea how many of the features are causing the problem," Bird explains.
Because the new arm would be a casting, ITD engineers included features such as internal ribs. As they designed the part, they kept in mind that the solid geometry would become the basis for the finite element model in Pro/MECHANICA. This is crucial, says Bird, to creating the seamless link between design and analysis that makes multiple design iterations feasible.
"When we designed this casting, we had the proper process in place to ensure that there were no problems when the CAD model was converted to a finite element mesh," he says. "That way, we weren't limited by problems with geometry that would have limited the number of designs we could evaluate."
ITD engineers evaluated 40 design iterations in all. It typically took them less than a week to make and test a significant change. They made minor changes daily. Major changes were analyzed for both stress and deflection in Pro/MECHANICA, as the deflection could not exceed that of the existing part.
Engineers worked with the pattern maker during this process to ensure the part was easy to cast. That meant avoiding overly heavy areas that would cause shrinkage; ensuring good dimensional control of the part; and making sure the part would fit into the flask sizes used by the target foundries.
Transfer of design geometry, analysis results, and other project information between ITD, Deere, and Voss Pattern Co. was handled through ITD's web site. Because everyone involved in the Deere lift arm redesign had access to all pertinent data through this web site, travel and face-to-face meetings were kept to a minimum.
"I suggested changes to the lift arm's shape that would make it easier to cast, and ITD evaluated my changes to make sure the part still met the functional requirements," says Dick Voss, owner of Voss Pattern Co. "The beauty of this approach is that when you have the final part, you know it will work." Total production cost savings for the part is expected to be $200,000 annually. ITD saved Deere an additional $100,000 during development by testing prototypes in software rather than building physical models
Contamination standards change hydraulic evaluation and reporting
By Bruce Wiebusch, Regional Editor
Milwaukee-The International Organization for Standardization (ISO) reports that experts from China, France, Germany, Italy, Japan, the Netherlands, the United Kingdom, and the United States joined forces to develop international standards that will change how people worldwide evaluate and report solid particulate contamination and filter performance in hydraulic systems. The report is the first of four key standards just published by ISO that address contamination issues.
ISO 11943:1999, a new standard, specifies a calibration and validation process that makes on-line automatic particle counting of suspended particles in hydraulic fluid more accurate and consistent. On-line particle counters sample hydraulic fluid directly from the line of an operating system and then return it, thereby eliminating the need for sample containers. "The standard provides particle count information more accurately and quickly," says Karen Boehme of the National Fluid Power Association.
The three other related international standards that will replace existing standards address calibration of automatic particle counters (ISO 11171), coding of the level of solid particulate contamination in hydraulic fluid (ISO 4406), and multi-pass testing of hydraulic filter elements (ISO 16889). ISO expects to publish the standards by the end of 1999.
ISO will also publish a technical report, ISO/TR 16386, that discusses the impact of these standards on how solid particulate contamination and hydraulic filter performance are evaluated and reported. The technical report provides guidance for those who use the standards as well as data resulting from their application.
One additional standard, ISO 2942, addresses contamination control in hydraulic systems. This standard focuses on the verification of fabrication integrity as well as the determination of first bubble points of hydraulic filter elements. Standard ISO 2942 was reviewed in the summer of 1999 and is currently undergoing additional review.
For more information on the ISO standards, contact Karen Boehme at the National Fluid Power Association; telephone (414) 778-3345, e-mail firstname.lastname@example.org.
Smart seats adjust for acceleration
By Roy O'Connor, Contributing Editor
Böblingen, Germany-Although auto-makers design car suspensions to handle fast driving, cornering at speed can still throw the driver and passengers sideways, pressing them uncomfortably to the edge of their seats. Sporty, bucket-shaped seats help prevent this, but many drivers feel too constrained. An alternative method of tackling this problem is to make the seat change its shape in response to car movements.
| Control system dynamically alters seat shape when car rounds curve.
Applying an electric motor control system from Valeo Auto-Electric, Lear Corp. dynamically alters seat shape when the car is being driven round a curve. The seat cushion, controlled by electronics integrated into the system, tilts slightly towards the center of the curve, reducing the effects of the inertial forces. The electronic system calculates the appropriate adjustment angle--as much as six degrees left or right--from the acceleration data.
"Six degrees tilt may not sound like very much," explains Alex Koblischke, designer of the Lear BKS system, "but on a country road with a 300 m-radius curve, and at a speed of 80 km/hr, the system compensates the lateral forces by up to 45%."
The lumbar region of the seat on the side remote from the center of the curve moves to provide support for the driver's back, while the back of the seat on the same side moves to support the shoulder region. Because the seat only alters shape when taking a curve, the driver sits comfortably with plenty of freedom of movement when traveling along the straight. Two motors from Valeo provide the seat movement--one tilts the seat cushion, the other changes curvature of the seat back.
| Lear’s acceleration compensated seats rely on added electromechanical components. Earlier pneumatic systems required bulky pumps and compressed air reservoirs.
|| Active seat control system has two major control loops—one for the seat cushion and one for the seat back. Position values are fed back to the control motor drives and to the microcontroller handling the data evaluation.
Regarding seat construction, Koblischke adds, "Basically, this system complements a conventional seat to maintain normal comfort when driving straight. This means that all driver-related settings like seat height, slope of seat back, and head rest remain unaffected."
Re-engineering shrinks cycle time
By Laurie Ann Toupin, Associate Editor
Yellow Springs, OH-Vernay Laboratories, manufacturer of precision-engineered fluid control products, used to take two years to bring a new part into production. After going through a major process re-engineering, the company now goes from design to manufacturing in three months.
Vernay's products--synthetic rubber valves and seals--are used by a variety of industries including automotive, electronics, appliance, and medical.
Their shortened design time was the result of several steps. First, the company adopted a universal tool system to accelerate tool production. In addition, the company installed Solid Edge from Unigraphics Solutions (St. Louis, MO). Previously, Vernay used 2D drawings to communicate design intent. People in analysis and manufacturing interpreted and recreated the information on the drawings for their own applications. Key to the re-engineering process was eliminating that duplication by creating a design once as a solid model and then re-using the data throughout development, says the company.
Vernay chose Solid Edge over a number of other PC-based solid modelers because "it's one of the most performance-minded packages on the market," says Richard Merriman, design engineering manager at Vernay. "Solid Edge requires fewer steps to perform an operation than the other programs we evaluated," Merriman explains. Vernay's management also believed that Solid Edge would be easy for people to learn. That has turned out to be true, according to Merriman.
Designers, for example, find that they can create solid 3D models of mold assemblies faster with Solid Edge than they could draw them in their previous 2D CAD system. The analyst shaves several days off his task by importing Solid Edge geometry directly into the FEMAP preprocessor from Enterprise Software Products rather than redrawing it. FEMAP, as a Solid Edge Voyager Partner application, provides an additional level of integration with the design geometry. Vernay uses two finite-element analysis programs, PowerSolver 6.0 from Aegis Software Inc. and CAEFEM from Concurrent Analysis Corp.
Toolmakers save several weeks by programming the mills, lathes, and EDM machines with the Mastercam computer-assisted manufacturing system (CAM) from Mastercam Corp. They import Solid Edge geometry directly into Mastercam, which is also a Solid Edge Voyager Partner application.
Vernay still produces hardcopy drawings for each new product, however, mainly for archival purposes and as a way to flag areas with tight tolerances. Engineers found that the process is more efficient if they create solid models first and then spin off drawings. "It is definitely faster to make drawings from a 3D model," says Merriman, "Especially when we have a large assembly drawing. When we change a component that is reflected on several sheets, we simply change the solid model and it updates all the views. With the old way, we had to physically change each view."
Merriman estimates the typical time required to design and create detailed drawings for new production jobs has dropped by 50%. "We've turned weeks into days and days into hours for most of the design jobs our department handles."
Motor controls manage massive concrete conveyor
Sandouping, China-Technicians from Ruggles Control Design (RCD), an Antioch, IL systems integrator, are completing final assembly on a motor control center (MCC) that they'll ship to the Three Gorges Dam project site in China's Hubei province. As the primary control contractor to Rotec Industries Inc. (Elmhurst, IL), RCD MCCs will control six Rotec concrete transporting and placing conveyor systems during dam construction.
As the largest hydroelectric project in history, the dam will stretch two miles across the Yangtze River. To this effect, MCCs must control nearly five kilometers (three miles) of movable conveyors, each system capable of delivering concrete at up to 420 cubic meters per hour. Controlled elements include motion, velocity, scales, and hopper gates for dispensing concrete onto the conveyor belts. Fifty-four motors of various power ratings and 89 miles of cable will be deployed for this portion of the dam's construction. Six batch plants at the site will continually dispense concrete on the conveyor systems for the next several years.
RCD designed the control system based on the Totally Integrated Automation concept from the Industrial Systems Division of Atlanta-based Siemens Energy & Automation Inc. Comprised of SIMATIC brand controls and instrumentation, each MCC uses a S7-416 programmable logic controller (PLC) as a central controller, along with Siemens' SIMOVERT Midi Master Vector drives, SAMMS electronic overload relays, trip units, Sentron SBA 800 enclosed case circuit breakers, and SIKUSTART soft starters. Communications back to the main PLCs is with Profibus, and optical fiber links the MCCs together to provide information to operator consoles.
These consoles on each MCC use industrial PCs, standard operator panels with membrane keypads, and NT-based HMI software developed by RCD with Visual Basic. In addition to basic graphical information (with both English and Chinese commands), operators will also be able to view an on-screen window with live motion video of the conveyor belts.
After the concrete finally stops flowing sometime around 2009, the dam will create a reservoir approximately 400 miles long. Designed to generate 18,000 megawatts of electricity for use in rural Chinese provinces, the dam will also provide flood management and improved navigation for the upper Yangtze.
Pilots test hybrid helicopter
By Benjamin B. Ames, Associate Editor
Olney, TX-Test pilots have been putting a hybrid helicopter-airplane through its paces in recent weeks. The CarterCopter is a fixed-wing aircraft still in development that its designers claim will be able to fly 230 mph at sea level and use its rotor for vertical takeoff and landing (see Design News, 1/8/96, p. 68). The five-seat craft avoids rotor stability problems at high speed by powering the rotor only prior to takeoff, then putting it in autorotation during flight, like a gyrocopter. The high-inertia, bearingless, two-bladed rotor has a continuous composite structure, comprising blades and hub. With its freewheeling rotor, the craft's thrust comes from a conventionally-mounted GM V6 pusher-propeller engine, allowing designers to claim a top speed of 400 mph at 50,000 feet and a range of 2,000 miles.
Airplane enthusiasts at the EAA AirVenture '99 conference in Oshkosh, WI, this July got to see the CarterCopter on the ground, but not in demonstration flight. The plane flew most recently on June 11, when it performed a 4 minute, 13 second flight pattern moving 116 mph at an altitude of 400 feet. It flew six more similar flights the next day.
The CarterCopter has three patents pending and 11 approved, including a high-inertia rotor blade, rotor rpm control and stability, a high tail boom design that protects the prop tip in a wheels-up landing, and shock-absorbing landing gear. Company founder and president Jay Carter Jr., a private pilot since 1967, worked at Bell Helicopter before starting his own business, designing a steam-powered car and manufacturing and installing wind turbines.
Engine has only 3 moving parts
By Jean Gonzalez, Western Regional Editor
Riverside, CA-University of California Riverside will evaluate a new internal combustion engine, which weighs just 120 pounds and contains three major moving parts. The OX2 engine is said to produce the same torque as a 3.8-liter V6 found in most cars today.
UCR’s College of Engineering-Center for Environmental Research and Technology (CE-CERT) will test the power, torque, emissions and fuel usage of the OX2 engine. Advanced Engine Technologies (Albuquerque, NM) licensed the OX2 engine technology to commercialize it with the backing of racing greats Carroll Shelby and Bobby Allison.
| Weighing just 120 lb with three major moving parts, the OX2 engine produces the same torque as a V6.
The engine is an 8-cylinder barrel configuration, using a stationary head and cam plate, and rotating cylinder block and piston plates. The OX2 measures 12 inches in diameter and 10 inches wide. It operates on a full four-stroke system, however it uses porting rather than valves. It has no camshaft, no distributor, no oil pump, and no water pump.
The OX2 has only three major moving parts, however it has eight pistons. Each cylinder fires twice per revolution, and two cylinders fire simultaneously, resulting in four times the output per revolution of a conventional four-stroke engine at the same displacement. Rev for rev, the OX2 can produce more torque and horsepower than a 350 cubic inch conventional engine, claims Advanced Engine Technologies. The engine can run on any combustible gas or liquid as fuel.
According to Advanced Engine Technologies’ Greg Howland, the direct-drive engine requires no transmission to reduce rpms down to manageable rates, and idles at 100 rpm. "The exhaust temperature is so low that you could hold your hand over the exhaust pipe all day and the output is lukewarm, " says Howland.
"If the performance figures are correct, the OX2 engine is the most significant advancement in combustion engine technology that I have seen in my lifetime," says Carroll Shelby. Shelby says he has witnessed a demonstration of the engine producing 170 ft.-lb. of torque at 1,250 rpm.
2003: Gullwing returns
By Kenneth O. Gibbs Jr.
Stuttgart, Germany-DaimlerChrysler and McLaren Cars Ltd. have partnered to revive and reinvent the legendary Silver Arrow with the Mercedes-Benz Vision SLR, scheduled for launch in 2003. Jurgen Hubbert, board member of DaimlerChrysler responsible for passenger cars, promises the SLR will be "an incomparable combination of the brands characteristic design, and unparalleled safety, quality, and performance..."
A state of the art manufacturing facility under construction in Woking, England will produce the SLR, which will feature much of the technology currently found in the world championship Formula One McLaren Mercedes. The V8 naturally aspirated engine from the S-class has been enhanced for the SLR to give zero to 60-mph acceleration in 4.2 seconds, and a top speed of 199 mph. Carbon fiber and other high performance materials used in the chassis result in the 3,080 lb target weight, but still ensure rigidity and occupant protection.
Other technology. Xenon adaptive headlights let drivers adjust beam intensity, and the lights automatically follow the steering angle and can swivel in all directions. Beam screens ensure the prescribed range of the beam when dipped, but automatically fold away when high beam is engaged. Cornering, and winding roads activate high-powered LED's integrated into the side flanks for increased visibility.
The normal brake servo unit is replaced with an electro-hydraulic brake (EHB) system with integrated sensors, digital data network, high-pressure reservoir, and wheel-pressure modulators that calculate and apply brake power to wheels individually. The new system builds up pressure noticeably faster than conventional brake systems, and automatically adjusts brake pressure when it recognizes reductions in brake action from fading.
If this car drives as good as it looks, the Vision SLR may be the vision for the future.
A sport wagon for the stealth conscious
By John Lewis, Northeast Technical Editor
Newton, MA-On my third pass by, I finally spot the BMW 528i wagon nosed into its parking space. From behind, it's not what I expect. Cloaked by a discrete rear spoiler, roof rails, and a sloped one-piece, lift-up tailgate, the wagon blends right in with the other cars around it. The front of the car, though, sports the more familiar look of a luxury BMW.
It's all luxury on the inside too. The smell of leather engulfs me. Once nestled in the electrically adjustable seat, I put the clutch in and turn the key. I can hardly tell it's running. Revving the engine produces a pleasant grumble from below.
Price as tested:
To say my first stop at the garage exit was abrupt is an understatement. What I considered to be only a slight touch of the brake pedal brought the car to a hasty, but certain stop. Once accustomed to the brake action, however, the driver can stop the car on a dime.
In contrast, on the open road this car wants to go fast. Persistently urging me for more, the aluminum-block six-cylinder engine has plenty of power. I can't imagine what the eight-cylinder 540i is like. Shift-lever action is even and precise, but with a rather long stroke.
The front suspension's coil, strut, antiroll-bar, and gas-shock design provides tight, but smoothly exact steering. A 4-link, coil-spring rear suspension and traction control maintains dynamic equilibrium and balance. This stealthy sled has a sense of poise that stirs self-assurance in almost any driving situation and its visually unassuming nature helps push limits without detection.
Although this wagon has more storage space than a sedan, I wouldn't call it a station wagon. Four adults can ride in comfort. But with two children and Labrador retriever in back, the car fills to capacity pretty fast.
Linear motors drive car
By Roy O'Connor, Contributing Editor
Bielefeld, Germany-Although many electric car designs use asynchronous motors for the power unit, they are normally conventional rotary motors. Now, the Fachhochschule Bielefeld has developed a drive for electric cars based on linear motors. The linear motor configuration is intended to save weight, thereby increasing trip efficiency.
| Wheel rim and asynchronous linear motor rotor form a single unit; a strengthened rim counteracts the high lateral forces created by the linear motor. In its simplest form, the rotor is a copper ring supported on an iron ring, which is laminated to reduce eddy currents. If first and last pole pitches in the stator windings overlap to produce a full stator, the design approaches that of a conventional motor.
Electric cars suffer from the disadvantage that batteries have an energy density much less than that of gasoline--a 300 kg lead-acid battery being roughly equivalent to two liters of gas. Not only that, a recharge or "tank-filling" takes about ten hours. Stored electrical energy, consequently, must be used very efficiently. That is why designers look for ways of reducing vehicle weight so that less energy is needed to bring the vehicle up to speed.
One way is to replace the centrally driven motor with four motors, each directly driving a wheel. This gets rid of a large number of mechanical components needed to transmit torque to the four wheels, including couplings, gears, drive shafts, and differentials. Each directly coupled motor, however, increases the unsprung mass, i.e., those parts of the vehicle which follow the road contours. This means that some of the weight lost must be offset by the extra weight of stronger suspension components.
Because there is no direct mechanical connection between the rotor and stator in the linear drive, the stator can be fitted on the sprung chassis. As a result, the linear configuration enables the rotor/wheel assembly to move vertically on a sprung axle with respect to the stator for a true independent suspension.
"The only parts which rotate with this electric car drive system are the wheels themselves," says Klaus Hofer, professor of Electrical Engineering at FH Bielefeld. "Friction and vibration losses associated with rotating parts have been reduced to an absolute minimum.