Honda Date of issue: April 01, 2002
Introduction of Personal Watercrafts AquaTrax F-12/F-12X Installing a 4-Stroke Engine
The AquaTrax F-12 and F-12X Personal Watercraft (PWC) were developed with design goals of excellent driveability and environmental suitability superior to the existing 2-stroke engine PWCs. A 4-stroke engine and turbo charger were installed for the first time in PWCs. As a result, they passed the EPA 2006 emission regulation and the CARB 2004 emission regulation for the first time in PWCs, and driveability exceeded that of the existing 2-stroke engine PWCs. The turning ability of these PWC, like that of a motorcycle, was realized through a newly developed water jet pump suitable for the characteristics of a 4-stroke engine, and the hull bottom of Honda’s original shape. Thus, the level of existing PWCs was changed completely.
By Masahiko TSUCHIYA、Mamoru URAKI、Noboru YOKOYA、Takao KOCHI、Takaharu KUROSAKI、Hajime SHOGASE
Development of Honda Flagship Outboard Motor “BF225/200”
Honda has developed 225 and 200-horsepower outboard motors powered by a 3.5-liter V-type 6-cylinder (V6) engine, the largest such outboard motors in the world, as the flagship models in its 4-stroke outboard motor series. The BF225/200 models are the first 4-stroke outboard motors to use the VTEC (variable valve timing and lift electronic control system), a variable intake and O2 feedback system. The resulting engine performance also makes them the world’s first outboard motors in the 200-HP class to achieve emissions levels that satisfy the year 2008 values for marine engine exhaust emissions set by the California Air Resources Board (CARB). At the same time, they have achieved a highly balanced performance improvement, with a maximum torque that is 10% greater and fuel consumption that is approximately 15% lower than previous models. The adoption of non-chrome coating methods for exterior parts on these motors has achieved the environmental compliance while maintaining coating quality on a par with previous models. In terms of comfort, their low vibration and low noise place them at the top of their class. The out bank exhaust manifold design with the same construction as V6 automotive engines and the use of a plastic inlet manifold makes these models lightweight and compact enough to replace conventional 2-stroke outboard motors without requiring any modification to the boat. Honda has achieved these performance levels while maintaining high reliability and simultaneously reducing cost by standardization of basic specifications and communizing parts with it’s automotive V6 engines.
By Masaki TSUNODA、Kentaro FURUYA、Sadafumi SHIDARA、Masayuki OHSUMI、Makoto YONEZAWA、Ryuichi KIMATA
Introduction of CRF450R Equipped with 4-Stroke Engine
The first 4-stroke engine motocrosser (CRF450R) in Honda was developed focussing on the fastest motocrosser for all motocross races and to enable riding without stress according to the rider’s intention. The development targets were to obtain a linear characteristic in torque and traction, which was controlled easily by adopting the 4-stroke engine, and to achieve the equivalent power-weight ratio to the 2-stroke engine motocrosser of the same race class. A lightweight forged piston with an extremely short skirt, a valve train of SOHC 4-valve engine (UNICAM system), titanium inlet valves, and a separated lubrication system for both the crankcase and the transmission were adopted in the engine as means to get a liner characteristic in torque and high power. As a result, 29.5 kg of engine mass and 41 kW of maximum power were achieved. Engine startability via the kick-starter was also improved by adopting a newly developed auto-decompression system. A total vehicle mass of 102 kg was realized by lightening each part of the frame body and suspension through techniques such as a newly shaped aluminum frame and a titanium exhaust pipe.
By Kazuhiko GOGO、Yasuo SHIMURA、Norio HOSHI、Takanori OKUMA、Akifumi NOMURA
Development of Hybrid HS1390i Snow Thrower
Honda has developed the HS1390i hybrid snow thrower for general consumer use based on the key concept of enhanced handling and operability. The snow clearing system is driven by an engine that simultaneously generates power for two drive motors. Computer-controlled travel motion combined with automatic load sensitive speed control make travel motion and work smooth. Operator load has been reduced by mounting the driving levers on the driving system frame and placing the operating controls in a fixed location. In addition, the use of an electric operating system reduces the amount of force required to operate the various controls. Fuel consumption per volume of snow removed is also better than previous models, making this product strongly competitive in the market.
By Jitsumi HANAFUSA、Tsutomu INUI、Takahiro YAMAMOTO、Tsutomu WAKITANI
Development of a New Power Train for the Civic Hybrid
The Civic Hybrid was developed as a compact passenger hybrid car that achieves both low fuel consumption and cleaner operation from the viewpoints of preserving the global environment and conserving resources. The engine has lean-burn countermeasures added to the base I-DSI 4-cylinder 1.3-liter SOHC 2-ignition plugs/cylinder engine mounted in the “Fit”. In addition, the cylinder idling system has been adopted to increase the regenerated energy during deceleration. The hybrid system is based on the Honda IMA system, and the maximum regenerative torque has been increased by approximately 30% by improving the magnetic circuits of an ultra-thin DC brushless motor and adopting a new rotor manufacturing method. Fuel economy is improved by a new hybrid power train incorporating a CVT that further improves transmission efficiency, thus achieving the low fuel consumption of 29.5 km/l in the 10-15 mode. New emission technologies applied are a new exhaust system with a NOx adsorption reduction type three way catalyst and air-fuel ratio control achieved 75% reduction from the 2000 emission standards in Japan. The power control unit, which is the IMA system control unit, was downsized and located behind the rear seat, thus ensuring comparable trunk capacity to the base vehicle of the Civic Ferio.
By Toshiaki KAKU、Toshiyuki SATO、Teruo WAKASHIRO、Masato MATSUKI、Toshihiro KAMIYAMA、Masahiro KANDA
Development of a 1.7 L CNG Engine for the 2001 Civic GX
Honda has upgraded the Civic GX, which has been in production since 1998, with a newly developed CNG engine for the 2001 model. Based on the gasoline engine in the 2001 model Civic, this CNG engine was given larger displacement and an improved air intake system for better torque at low to medium speeds. A layout that integrates the air intake system and the CNG regulator was adopted to make the power plant more compact. The new Civic GX is the world’s first vehicle to be qualified as an AT P-ZEV by the CARB. In order to satisfy the AT P-ZEV requirements, the vehicle was given the capability for quick light-off of the catalyst from a cold start, high-precision air-fuel ratio control, and reduced exhaust emissions. It has certified for Japan ULEV status. This model also achieved a 7% improvement in city driving fuel economy over the 1998 model by changing the transmission that is paired with the CNG engine from a 4AT to a CVT.
By Yuji YAMAMOTO、Takushi TODA、Masato MATSUKI、Tadanobu OHMORI
Research of Hydrostatic CVT for Passenger Vehicles
Hydraulic Continuously Variable Transmissions (“CVT”) have a large capacity for power transmission and have achieved proven results in industrial machines. Research was conducted on hydraulic CVT for use in passenger cars with large engine displacement, particularly in the areas of fuel economy performance, high-speed performance and quietness where passenger cars have higher demands compared to industrial machines. An HMT (Hydro Mechanical Transmission), which has the highest efficiency of all hydraulic CVT, was adopted to improve efficiency at cruising which greatly affects fuel economy when cruising at high speeds. In addition, the lock-up brake mechanism and the hydraulic pump and motor portions were improved to reduce agitation, resulting in a 6% improvement in efficiency when cruising at 50 mph. The hydraulic motor rotates at high speed during high-speed cruising, but centrifugal force has little effect and prospects for durability were obtained by adopting a bowl type slipper and improving the cooling method. A method for reducing noise was also derived by focusing on fluctuations of swash plate movement, which are correlated with noise.
By Akihito OKUDA、Mikihiro TAKANO、Kazuaki SAKAI、Tetsushi ASANO、Masashi TANAKA、Takashi IINO、Koichi FUSHIMI
The Development of a New Compact CVT for the Fit\Jazz
Honda has developed a new continuously variable transmission (CVT) for use with new-generation power plants, and this compact, lightweight CVT, known as the Multimatic S, has been installed on the Fit. The redesigned flywheel, oil pump, clutch, and transmission case used in this CVT reduce the number of parts by 15% while simultaneously lowering friction and improving transmission efficiency by 5% over the 1999 model Logo. The new electronic control also provides creep control optimized for cruising conditions and automated switching of the shift schedule. These have yielded both improved fuel economy and a feeling of responsiveness to a wide range of driver demands.
By Shuji ICHIJO、Makoto SUMI、Takashi HASEGAWA、Shuichi FUJIMOTO、Yukihiko FUKUSHIMA、Hisashi KUNII
Development of Engineering BOM Data Management System
A new engineering bill of material (BOM) system was developed in order to shorten the development cycle and improve BOM accuracy. This BOM can perform integrated management of basic product information of all vehicle models, all types, and combinations of frame, engine, transmission, and so on. It also improves drawing release efficiency and facilitates connection with other systems. Based on a commercially available product data management package, this system has a three-tier system architecture for easier data linkage, and it runs on the sophisticated Windows NT Server for improved operation performance.
This not only allows management of basic product information for all vehicle models, but also makes it possible to centrally manage information sharing and drawing data from the initial development stage through to mass production. Significant improvements have been made in the efficiency of design drawing release and reception work flow as a result.
ByMasataka YAMAMOTO、Hideyuki TANAKA、Wataru FUJITA
Technology for Applying Solid Lubricant to the Piston Skirt of Internal Combustion Engine and Its Effects
A molybdenum disulfide piston coating technique was developed using the Wonder Process Craft (WPC) processing method to apply high-purity molybdenum disulfide onto the sliding surface of the piston skirt for an internal combustion engine. This technique is a world first, and the pistons manufactured using this process gained the full effect of durability while also achieving significant reduction in sliding resistance at a low cost because the coating process does not require use of a binder. The technique is also noteworthy for making manufacturing easier, since it does not alter the dimensions, shape, or surface roughness of the base material. In addition, this piston manufacturing process uses compressed air and molybdenum disulfide powder. The molybdenum disulfide discharged from the process can also be recycled. Thus the process realizes zero waste and addresses the current need for environmentally friendlier technology.
by Hidemi OGIHARA
The Effect of Geometry on Stiffness and Deformation in Exhaust Manifold for In-line 4-Cylinder Engines
Investigations were conducted on a quasi quantitative analysis method for exhaust manifold stiffness and deformation that is useful when designing exhaust manifolds for in-line 4 cylinder engines. This method analyzes the exhaust manifold as a combination of beams, making it possible to obtain the effects of the dimensions and shapes of major parts of exhaust manifold on stiffness and deformation. These results clarified the effects of various exhaust manifold shape characteristics (aspect ratio, branch ratio, offset ratio) on non-dimensional stiffness, and also the effects of aspect ratio on the non-dimensional warping quantity. In addition, the effects of each of the aspect ratio, collective part different angle, branch ratio and offset ratio on non-dimensional stiffness and deformation when the dimensions and shape of each exhaust manifold part are changed could also be clarified by obtaining the degree of effects of each factor. The proposed method is effective for determining and investigating the validity of major approximate dimensions, particularly when designing new exhaust manifolds with limited outer dimensions. Exhaust manifolds can be efficiently developed by performing CAE calculations on exhaust manifold shapes that have been determined using this method.
By Masaru ENOMOTO
Study of Simulation Technology for Limit Drivability
Using conventional technology, it used to be difficult to calculate vehicle behavior in a limit handling situation by mechanical system analysis and predict that behavior with a high degree of accuracy. A method using tire modeling based on Magic Formula has been developed, which has been optimized for limit behavior, and accounts for lateral tire deflection. From a vehicle standpoint, a method using car modeling based on conventional vehicle model has been developed for improvement of the suspension rate and traction torque control. These measures have made it possible to perform mechanical system analysis calculation of vehicle handling behavior up to the limit. As a result, it has become possible to attain a high degree of accuracy in predicting vehicle limit behavior in turns, which is one of the dynamic characteristics for limit drivability.
By Yasuhiro MIYATANI、Yuji SATO、Shinta ARAI、Takayuki TOYOSHIMA
Establishment of a Development Method of a Water Jet Pump for 4-Stroke Personal Watercrafts
Honda’s first Water Jet Pump for a Personal Watercraft with a 4-stroke engine has been developed. In the development, correlation of the calculation results with the actual test results was verified, and design tools such as an examination method of intake shape optimization, a characteristic calculation method for various aerofoil shapes, and a prediction method of Water Jet Pump performance were established. Using these tools, two Water Jet Pumps that matched each of the 4-stroke engines with different output power have been developed.
By Masahiko TSUCHIYA、Takashi WATANABE、Tomohiro FUSE
Development of an Off-Throttle-Steer System for Personal Watercraft
Personal Watercrafts (PWC) are vehicles propelled by a water jet and steered by changing the direction of the water jet.
Because of the decreasing of the thrust when the throttle is fully closed during running, the steering force also decreases. This phenomenon is different from that of land vehicles. To minimize this, the Off-Throttle-Steer (OTS) System has been developed Basically, the system controls engine speeds using the signal of full steering, and also uses a throttle opening, a running speed of PWC predicted by engine speed, and a timer for determining the control timing as other control signals. Thus, a natural steering characteristic was obtained by balancing a turning characteristic at high speed and controllability at low speed.
By Mamoru URAKI、Takao KOCHI、Goro YAMASAKI、Hajime SHOGASE
Reliability of Lead-free solder for Automotive Electronic Devices and Its Applications
Although an Sn-Pb alloy is generally used for solder at present, environmental considerations have occasioned a search for lead-free solder alloys. The present research evaluated lead-free solder to determine whether it could replace Sn-Pb solder, beginning with the evaluation of the reliability of the solder joint. The evaluation examined reliability under five degradation modes: thermal fatigue, intermetallic compound layer, creep, vibration fatigue, and ionic migration. Lead-free Sn-Ag-Cu solder showed the longest life under thermal fatigue, which is the most crucial element in reliability, and it was confirmed to have reliability superior to Sn-Pb solder in the thermal environments encountered in ordinary use. The Sn-Ag-Cu solder was then put into use as a product in a keyless entry transmitter, where it was demonstrated to satisfy product quality and endurance quality requirements.
By Masato MORIYAMA、Junichi OHMURA、Tomoo WATANABE、Tsunehisa HATA
Development of Pb-free Free-cutting Steel Enabled to Omit Normalizing for Crankshafts
A Pb-free free-cutting steel for crankshafts was developed which resulted in the omission of the normalizing process. In order to omit the normalizing process, adequate hardness and fine microstructures, as obtained in normalized steel, must be achieved in the free-cutting steel after forging and air-cooling. These requirements were met by adjusting chemical composition of steel. A target was to achieve productivity of the developed steel based on Ca-S free-cutting steel, equal to that of the conventional Pb-S free-cutting steel. As a result of examining non-metallic inclusion’s composition, volume, shape and dispersion in the steel, it was found that the shape and dispersion contributed to an improvement in machinability. By manufacturing a crankshaft with this steel, the cost of the normalizing process was eliminated and the reduction of Pb by 13 g became possible for a motorcycle equipped with a 954 cm3 engine.
By Satoru SUWA、Atsushi AMATAKA
Development of a Titanium Material by Utilizing Off-Grade Titanium Sponge
A titanium alloy for forging and a pure titanium material for exhaust systems have been developed for the purpose of reducing the weight of a motorcycle frame and improving the engine performance. A feature of the material is the use of off-grade titanium sponge that includes many impurities for production of titanium ingot. Stable characteristics have been obtained by controlling oxygen equivalent after setting the volume of tolerable impurities by considering mechanical properties and productivity. In spite of low-cost, this material design provided the same design strength compared to the conventional material, and enabled production with existing equipment. Using this new material and changing the manufacturing and surface treatment process enabled us to provide titanium parts at a lower cost. This technology is a fundamental one for producing titanium raw material for motorcycles and automobile applications, and it is expected to apply to other titanium alloys.
By Yuji MARUI、Kyo TAKAHASHI、Toyotaka KINOSHITA
Weight Reduction with Plastic Foam for Structural Components of Vehicle
Focusing on absorbing energy in the side frames of a vehicle as compressive deformation occurs during a frontal impact, increased energy absorptance and weight reduction of the structural components of a body do occur by filling them with urethane foam. It was found that it is possible to achieve approximately 30% weight reduction by filling urethane foam and modifying cross-section structures while insuring flexural rigidity and absorbed energy equal to that of body frames. At the same time efforts were also made to construct CAE technology that enables investigation into a lightweight body frame structure filled with plastic foam. The difference in absorbed energy between CAE simulations and tests with an actual hybrid frame unit consisting of aluminum piping (shell element) filled with urethane foam (solid element) was approximately 10% while under 50% compressive deformation or more.
By Akifumi SONODA、Yasushi TOSHIMITSU
Development of New Pre-processor for Car Body Analysis
A new pre-processor was developed to shorten the finite element modeling process while improving calculation accuracy for car body analysis. The new pre-processor made it possible to create high quality models efficiently in a short time regardless of the skills and experience of the modeler. This was achieved by automatically identifying and correcting penetration and intersection between elements after division of a body in white into shell elements, automatically analyzing and converting spotwelds and other connection data into finite element data, assigning accurate material properties, automatically adding mass and incorporating dummies and barriers by compiling a material property, parts and mass database. In addition, the pre-processor was also given simple shape modification functions allowing model changes to be made in a short time when investigating specifications.
By Fumio NAKANO、Atsushi IWAMOTO、Kenji TAKADA、Norikazu MATSUURA
Research for Vibration Analysis with Full-Vehicle Model
Techniques of full vehicle analysis directed at all suspension and body-related parts were combined with test-based engineering and simulation techniques in a two-sided approach intended to develop a technology for reduction of floor and steering vibration. The test-based engineering clarified the mechanism of vibration initiation by means of full vehicle modal analysis, operational deflection shape analysis, and transfer path analysis implemented by excitation of the suspension.
Modifications were then made to an actual car based on the results obtained from analysis. The simulation techniques involved modeling of all the subject parts, and the creation of a finite element model (160,000 nodes) that matched the actual car with a high degree of accuracy. Sensitivity analysis was then applied to analyze the weak points, and calculations were made to implement modifications in the finite element model. Both the test-based engineering and the simulation techniques were confirmed to reduce vibration levels in the actual car, thus substantiating the validity of these analytical techniques.
By Toshiya YOKOI、Kengo OKAMURA、Masaki NAGAHISA、Jiro NINOMIYA
Development of Metal Pushing V-Belt for Continuously Variable Transmission
Metal pushing V-belt is the core technology of CVT. Up to the present, only Van Doorne’s Transmissie b. v. has engaged in the mass production of this component. As a result of knowledge obtained from ongoing analysis of the power transmission mechanism, newly conducted measurements of block compression force for slack string and numerical analysis, Honda is the first automotive manufacturer to have independently developed the metal pushing V-belt for mass production. This newly developed metal pushing V-belt features reduced pitch diameter and increased power transmission, to achieve compactness of the CVT and a wider ratio range.
By Tooru YAGASAKI、Hideaki AOYAMA、Yoshinari OKADA、Kazuo ISHII、Mamoru ARIKAWA、Toshihiro SAITO
Application of Metal Pushing V-Belt Stress Simulation with CVT Pulley Stiffness
A simulation method was developed allowing simultaneous evaluation of dynamic behavior and ring stress for the estimation of the durability of metal pushing V-belts for CVT’s. The high rotational speed range of the CVT is simulated utilizing the finite element method used in crash analysis. This paper focuses on dynamic behavior of the pulley, and the simulation method, which was modified to allow the pulley stiffness to be reflected. The pulley stiffness values are found by applying static loading to the three-dimensional FEM model. As a result, it is found that the flexional stiffness affects the ring impact stress at the pulley entrance and exit. Furthermore, the mechanism of contact between the ring edge and pulley surface or the element due to the ring misalignment caused by the pulley flexion is clarified. For the first time, these results make it possible to obtain design guidelines for the pulley stiffness that includes consideration of belt durability.
By Takemasa OKANO、Toshihiro SAITO
Development of a Spin Forming Procedure for CVT Pulley Covers
The metal pushing V-belt type continuously variable speed transmission (CVT) commonly has a hydraulic chamber that is formed by fastening together the movable pulley and pulley cover parts. The mechanism by which damage occurred to the pulley cover in the spin-formed fastening portion during development was clarified. In order to understand the damage mechanism, the area of the pulley cover subjected to spin forming was examined with a scanning electronic microscope. This revealed that voids had formed inside the examined area, as expected under the theory of ductile fracture, and it was confirmed that durability varied with the form of the voids. Quantitative treatment of the damage was made possible by numerical analysis of the mechanism of void formation using McClintock’s equation for damage evaluation. It was further confirmed that the results of this numerical analysis agreed with the results of durability tests of the pulley, verifying the validity of the analytical values.
By Toyoji HISATSUNE、Akihito OHASHI、Toshihiro SAITO
Optimisation of Transonic Gas Turbine Blades with Evolution Strategies
Evolution strategies belong to the class of evolutionary algorithms which are direct pseudo-stochastic search methods which mimic the principles of Neo-Darwinian evolution. They are known to be powerful optimisation techniques in particular for the solution of multi-modal, noisy and non-differentiable complex problems. For problems where a continuous representation is “natural”, like the geometry of gas turbine blades, evolution strategies are particularly suitable. Besides the choice of the search operators, the representation is one of the most crucial elements in optimisation. The advantages and disadvantages of different approaches are discussed in this work. Furthermore, to evaluate different geometric alternatives the fluid-dynamical properties of the blades have to be estimated. We propose a framework in which a Navier-Stokes solver and a neural network approximation model are combined. In this way, the computationally expensive evaluation of the fluid dynamics can be reduced while guaranteeing correct convergence of the optimisation algorithm. Finally, the optimisation results are discussed and the performance of the optimised and the original blades are compared both for the simulation method and for the transonic windtunnel experiment. In both results it can be seen, that a high performance increase is achieved.
By Bernhard SENDHOFF、Markus OLHOFER、Toshiyuki ARIMA、Toyotaka SONODA、Yaochu JIN
Development of a Simple Model for Simulation of Engine Gas Flow
An engine model allowing real-time computation and having a high degree of reusability was developed for application as a system design tool and as hardware in the loop system (HILS) for electronic control unit (ECU) development.
A distinctive feature of this model is that it is composed of simple models of engine parts. These parts are units in which the gases flow through the engine, they are modeled by applying the law of energy and mass conservation.
The model was installed in a rapid prototype system and used to conduct a comparison with an actual vehicle while it was in operation. The results of the comparison confirmed that the engine air inlet mass rate, the pressure, and temperature in the inlet and exhaust pipes could be predicted with acceptable accuracy.
By Satoshi YAMAGUCHI、Hiroshi KOBAYASHI、Fumitomo KATAKURA
Prediction of Chain Load in Timing Chain System
A chain load prediction technique was established to investigate timing chain durability under conditions of a variable valve lift timing mechanism and a continuously variable valve timing mechanism. Modeling a tensioner with a relief valve and valve train made it possible to predict the chain load at different relief pressures and valve timings. Furthermore, telemeter techniques were also developed enabling direct measurement of the chain load at high engine speeds, which was formerly impossible. The validity of the simulation was also verified using an actual engine. These developments made it possible to predict the chain load up to high engine speeds at different relief pressures and valve timings.
By Hitoshi SUGAWARA、Hiroshi TAKAGISHI
Development of Gear Train Behavioral Analysis Technologies Considered Nonlinear Elements
It has been identified that the rotation behavior of gears is influenced by housing deformation, radial clearance, tooth elastic deformation, etc., in the modeling process of the behavior calculation model of a gear train in motorcycle engines. To maintain a high level of accuracy, influence factors were converted to the stiffness components in the rotational direction, and were built in the rotational transfer model of the gear train. Furthermore, a behavior calculation model of a crankshaft was combined as a drive excitation source of the behavior calculation model of gear train. Time domain numerical integration method was used for calculation of the transient response that changes widely by engine speed change. A jump phenomenon of response behavior of the driven gear was predicted that is a characteristic of a non-linear response. The calculation result accuracy was confirmed through correlation with an actual test engine. It was understood that this behavior calculation of gear trains could be used as a technological tool for engine development.
By Tadashi NIINO、Mitsuyoshi KAMIYA、Shingo UEDA、Tatsuo SUZUKI
Quantification of Luxury and Sporty Car Interior Sounds Perceived by the General Public in Different Markets
Sensory evaluation tests were conducted to clarify differences in Japanese, German, and American perception of car interior sounds. The results of statistical analysis indicate that perceptions can be classified under two major categories: Luxury and Sporty, and that car interior sounds can be represented by these two axes. Further analysis of the sensory evaluation tests showed that sound preferences could also be described by these same categories. It is seen that even people with different preferences could have the same perception of luxury and sporty sounds. By country, a sporty acceleration sound was most preferred by Japanese, American, and German subjects, respectively. An application was developed that is capable of computing objective values for luxury and sporty sounds.
By Junji YOSHIDA、Kousuke NOUMURA
Research of Semi Solid Casting of Iron
One result of the research on semi solid casting of iron is the development of parts having qualities that combine the superior material properties of iron with the dimensional accuracy of aluminum die-cast parts. In addition, this manufacturing method also improves the factory environment by eliminating the need for sand molds, and it utilizes the same equipment and facilities in an Al-thixo casting plant. To establish this technology, research was conducted on iron material (composition iron-carbon-silicon), molding methods using optimal billet heating speeds and copper die materials, and methods for the continuous casting of raw material billets for Fe-thixo casting. This manufacturing method was studied with an oil pump cover, in which the oil pump is directly driven by the engine crankshaft, and the same dimensional accuracy was obtained as the conventional aluminum die-cast product. Furthermore, an improvement in the volume efficiency of the oil pump was also confirmed due to the stiffness improvement and clearance reduction effects.
By Hiroaki UENO、Isamu TAKAGI、Masayuki TSUCHIYA
Development of Sinter Diffusion Bonding for Rotor Core of Hybrid Car
This research focused on composite technology to bond materials for rotor cores, which require both magnetic properties and mechanical properties at once, and analyzed diffusion bonding of sintered material and the bonding area as a factor affecting it.
As a result, it was determined that the strength of the bonding zone depends on the bonding area, and diffusion bonding was verified as an applicable technique for bonding magnetic material and structural material, which are different materials. This report describes the establishment of a sinter diffusion bonding technique that provides satisfactory bonding strength. This was accomplished by improving the bonding area through application of pressure by press fitting of the inner and outer components, which was in addition to the difference in thermal expansion of the sintered material. Application of the developed material to rotor cores for use in hybrid cars has made it possible to achieve both functionality and strength, to significantly improve productivity, and to reduce costs by 50%.
By Toshiyasu KOMATSU、Satoru SHINZAKI、Kazuo ASAKA、Youichi NAKAHARA