Honda Date of issue: Oct 01, 2000
Introduction of HONDA ASV-2 (Passenger cars)
In response to the Advanced Safety Vehicle Project Phase 2 (ASV-2) proposed by the Ministry of Transport, we have addressed the two topics below with reference to the results from analysis of actual traffic accident conditions. After selecting effective technologies, we fabricated test vehicles for each of the objectives and moved forward with the research.
• Safety-enhancement through the reduction of both driver operating burden and rear-end collision damage through driving and operational support using CCD camera, radars, and related technology (Honda ASV-2, Vehicle 1).
• Enhancement of visual recognition to thereby provide information on the presence of motorcycles and pedestrians through information and visual support using communications and control devices, infrared cameras, and other technology (Honda ASV-2, Vehicle 2).
Research is proceeding on installation and implementation of each system, taking the basic approach of developing systems that will not interfere with driving operations. The test results on these systems have shown that they can be expected to produce accident-reducing effects. Minister of Transport approval was granted and road tests are being conducted on some of these technologies.
By Nobuyoshi ASANUMA、Takayuki TSUJI、Makoto KAWAI、Akio TAKAHASHI
Introduction of Honda ASV-2 (Motorcycles)
For the Advanced Safety Vehicle Project Phase 2 (ASV-2) as conducted by the Ministry of Transport of Japan, two types of prototype “ASV motorcycles” were produced to promote studies on safety. The research topics for the two types of prototype “ASV motorcycles” were selected from two viewpoints:
• Active safety technologies:
(1) “Inter-vehicle communication system” which provides information on the mutual presence of motorcycles and automobiles.
(2) “Discharge headlight for motorcycles” taking into consideration the high voltage unit and optimizing light distribution.
(3) “TUFFUP tires” applied to minimize pressure leaks due to punctures of tubeless tires with a self-seal gel sealed in their double structure chambers.
(4) “Air pressure monitor system” which will display air pressure and give an alarm when certain conditions exist.
• Passive safety technologies:
(5) “Airbag system for motorcycles” including an airbag, inflator and sensor system.
(6) “Advanced safety helmet” to reduce brain damage resulting from rotational acceleration of the head.
It is believed that potential accident reduction effects may be anticipated through the application of these technologies.
By Kazumitsu KUSHIDA、Toshio YAMAGIWA、Kazuhiro YAMAMOTO、Satoshi IIJIMA、Shigeru KODAIRA
Research for Emissions Reduction Systems for Small Motorcycles
Emissions regulations for small motorcycles are becoming increasingly stringent every year in various countries throughout the world. Therefore, we conducted research on high-precision control of the air-fuel ratio with an emissions reduction system for small, fuel-injection motorcycles, in particular, for motorcycles equipped with a 100cm3 four-stroke engine. Fuel injection is controlled by two injection amount maps applied according to throttle opening, engine speed and intake pressure. The control index used in this control system maintains the engine intake pressure peak when the intake valve is open in order to eliminate the major impact of intake pressure fluctuation exhibited by single-cylinder engines. Moreover, O2 feedback control and three-way catalyst systems were applied for exhaust emissions purification, and a small, power-saving fuel pump was developed to improve fuel economy.
In addition, a control system to obtain excellent starting ability with a kick starter was also developed. By adopting these systems, hydrocarbons were decreased to about 1/30 of the regulation value provided in the European motorcycle emissions regulation “Directive 97/24/EC chapter 5” (EURO-1), and the fuel economy was improved by approximately 20% compared to the base engine.
By Shunji AKAMATSU、Shuichi ISHIDA、Akira HAMAUZU
Development of General Purpose V-Twin Cylinder Engine GCV530/520
A 90-degree V-twin OHC vertical shaft engine for riding mowers has been developed. The V-twin cylinder layout and the aluminum sintered alloy connecting rod enabled the offset between cylinders to be decreased, the weight of the reciprocating parts to be reduced and the vibration level to be reduced by 50% compared to conventional single cylinder engines. The OHC construction with built-in timing belts, plastic cam pulleys and a turbo shaped cooling fan facilitated a noise level reduction of 4 dB compared to conventional single cylinder engines. Further, ease of assembly was improved with the application of uni-block cylinders, common parts for both cylinders and sub-assembly constructions. The engine size and cost are comparable to those of conventional single cylinder engines.
By Akihisa SHINODA、Takashi SUZUKI、Yutaka TABATA、Hiroshi MORIYAMA
Development of a 1.5L Lean-burn Engine for the 2001 Civic
A 1.5L SOHC-VTEC lean burn engine designed for the 2001 model Civic achieves higher fuel economy (20km/liter based on the 10-15 mode) and an emissions reduction of 50% over the Japan 2000 emission standards. Engine friction is reduced and a newly designed intake-port and combustion chamber are utilized for improved combustion characteristics. In addition, a NOx adsorption reduction type three way catalyst is used with the new exhaust system to achieve low-emissions.
By Masato MATSUKI、Hideji OHURA、Yuusuke KINOSHITA、Katsushi WATANABE
Super Ultra Low Emission System for the Accord SULEV
We developed the Accord SULEV (Super Ultra Low Emissions Vehicle) in order to comply with California’s LEV-II SULEV regulations. The emissions system employed is characterized by applying only an under-floor catalyst to attain the super ultra low emissions levels through sophisticated control technology. The improved three-way catalyst achieves both high conversion efficiency and low back pressure while using the same amount of precious metal as was used in the Accord ULEV. (1)
To satisfy SULEV standards using only the under floor catalyst, we developed technologies to increase emissions temperatures by controlling the amount of intake air and the ignition timing before the catalyst is active. This promoted quick catalyst light-off and enabled us to obtain leaner air/fuel ratios when the engine is started than was possible with the previous catalyst system.
Also, in order to further improve the conversion performance of the catalyst once it is active, we developed a New Secondary O2 Feedback Control System. This is an extremely high precision system that identifies the dynamic changes of the catalyst in real time and utilizes a sliding mode controller mechanism to predict changes in the post-catalyst sensor output.
The implementation of these technologies makes it possible to achieve the most rigorous SULEV standards, with engine output performance equivalent to our ULEV vehicle.
By Yuji YASUI、Hiroshi KITAGAWA、Kazunori OKAMATSU、Toshihiro MIBE
Development of New 2.0L Lean-burn Engine
A new lean-burn engine was developed as a 4-cylinder power plant for Honda’s next generation 2L-class vehicle. New mechanisms, such as i-VTEC which combines variable valve timing and lift control and continuously variable camshaft phase control, are applied to this power plant. As a result, a 113kW maximum output and a 186Nm maximum torque were achieved while at the same time a 14.2km/L fuel economy in the 10•15 mode and a 50% reduction over the Japanese 2000 Emissions standards were realized. Further, improved assembly conditions were facilitated by decreasing the weight of the engine by 10kg and the length of the engine by 54mm.
By Tomonori NIIZATO、Aruto HAYASHI
Development of an Engine Performance Data Acquisition System
In response to the trend of complex engine control, we developed a new generation engine data acquisition system equipped with high precision analyzing capabilities. This system enables measurement data processing using the Windows operating system and is able to perform cylinder pressure analysis. Further, the system can be used with engine test cells and electronic control units (ECUs) with various specs. It can also be used for automatic testing.
This system allows for the effective use of existing equipment. It is a simple system using a personal computer to process the acquired data. Also, the system employs a real-time operating system to control timing and thereby enable simultaneous data acquisition and processing.
As a result, we were able to achieve stable data acquisition, improved analysis capabilities, and a reduction in analysis time.
By Keiichi NAGASHIMA、Nobuaki TAKAOKA、Yasuyuki KIMURA、Takeshi TADAKA、Kenichi HATAKEYAMA、Yoshio MAEDA
Development of a Compact CVT for a Hybrid Car – Insight
The continuously variable transmission (CVT) used in the Insight, a hybrid car, was developed using the basic construction of Honda’s conventional CVT but with the aim of lighter weight, smaller size, and greater efficiency. This CVT optimizes line hydraulic pressure by utilizing a direct control system for pulley hydraulic pressures and differentiated drive-driven pulley pistons. The mechanism also uses such means as lubricant pressure control to reduce friction in each part, expand the ratio range, and improve the efficiency of engine-motor cooperative control. Further, the utilization of such devices as a forward-reverse select mechanism that operates with a single-pinion planetary gear served to reduce the number of parts.
By Makoto SUMI、Shuichi FUJIMOTO、Hisashi KUNII、Shouji OHTA、Tetsuro YAMAGUCHI
Active Control System for Low Frequency Road Noise Combined with an Audio System
An active control system for low frequency road noise in automobiles combined with an audio system was developed as a commercial application for the first time in the world. The system was installed in a station wagon. The purpose of this paper is to provide an outline of the system and describe the newly developed cost reduction technology used therein. A major factor in the successful application of active noise control technology to a commercial product is reduced system cost. The methods used to reduce costs include utilization of feedback control, implementation by analogue circuits, and common use of audio system speakers. This system reduces low frequency road noise in the front seat by about 10 dB and improves the audio system listening experience while driving.
By Toshio INOUE、Akira TAKAHASHI、Hisashi SANO、Tsuyoshi YAMASHITA、Dai ISHIHARA、Kenichi TERAI
Development of LCA Software for Automotive Parts
Conventional life cycle assessment (LCA) software was modified for application to automotive parts by adding an algorithm to determine end-of-life recycling paths identified and to calculate the environmental load for each of these paths. The software was tested in terms of its ability to calculate the environmental load in a bumper recycling system and results were confirmed to be equivalent to those calculated using a process analysis method. The software was applied to the LCA of rubber parts to compare the environmental load of the disposal of waste rubber in the factory process with that of recycling the rubber. Results showed that recycling waste rubber is effective in reducing the environmental load, but that it is very important to improve the quality of the recycled material and reduce the environmental load of the recycling process itself.
By Makoto IDA、Daisuke SUSA、Minoru MAKUTA
Optimization of Endmill Cutting Conditions for Nickel-Based Super Alloys
Parameter design based on the Taguchi Method was applied to the endmill cutting process for nickel-based super alloys rather than the conventional sequential methods or experimental design methods in order to optimize the cutting conditions.
“Machining transferability”, which compares the preset removal volume to the actual removed volume, was selected as the evaluation characteristic used in this method.
As a result, if an alloy is cut with the optimized conditions obtained with parameter design, an approximately 60% reduction in variations in machining transferability, in terms of the standard deviation, can be achieved as compared to the conventional conditions.
By Yasuhiko JINBU、Sachio KAJIURA、Kazuya KUWABARA
Technology for Reducing Engine Rubbing Resistance by Means of Surface Improvement
A surface modification method has been developed that uses shot peening to reduce the rubbing resistance on piston wear surfaces. This technique shoots roughly spherical ceramic bead having a central particle diameter of 40 μm with compressed air at a speed of 100 m/sec or more against the surface of the object to be processed. This peening treatment produces countless microscopic dimples that improve the oil retention capability of the treated surface and results in a 2–2.6% reduction of the lost output from an engine unit due to friction. Engine units with this treatment were subjected to an extended operation test to verify the sustainability of the effects from this treatment. The results showed that dimples remained on the parts even after an extended period of operation. The treatment was also proven to be effective in increasing the anti-seizure characteristics of the pistons.
By Shigemi KOBAYASHI、Hidemi OGIHARA、Hiroshi YAMADA、Tomoyuki KIDO、Masashi MURATA
Study of a Selective Catalytic Reduction Type Lean NOx Catalyst System
SCR (Selective Catalytic Reduction)-type Lean NOx catalyst ,which have continuously good activity of NOx reduction under the condition of excess oxygen, was focused for the NOx reduction in lean-burn exhaust gas.
In this study, the advancement of NOx conversion can be achieved by using Ir (iridium) catalyst. And the NOx selectivity, which in competitive HC oxidizing reaction, is improved by using new catalyst support.
Furthermore, the catalyst durability is improved by coating the material, which can convert NO to NO2, with the catalyst. The improved catalyst have good performance for practical use.
The improvement Ir catalyst showed the highest conversion in reduction of NOx (63%) on Japanese 10-15 mode, under the lean condition, with the engine controlling according to catalytic properties.
By Isao KOMORIYA、Ken OGAWA、Tomomi SUGIYAMA、Kazuhide TERADA、Takeshi NARISHIGE
Development of a Compact, Highly Efficient Traction Motor for Fuel Cell and Electric Vehicles
This paper describes the development of a compact, high-efficiency and high-power traction permanent magnet motor utilizing reluctance torque for electric vehicles.
The “Salient SPM” motor has salient between adjoining permanent magnets exposed on the rotor surface. This structure enabled magnet weight reduction by 35% compared with the interior permanent magnet (IPM) motor which generated equivalent torque.
Insulation between magnet and rotor yoke reduced the eddy current loss by up to 1 kW compared with a non-insulated motor.
As a result, maximum torque of 238 Nm and maximum power of 60 kW were obtained with this motor. The motor gave power density of 1.8 kW/kg, and torque density of 7 Nm/kg. At the same time, the overall motor-inverter efficiency reached 93% average drive efficiency when running in UDDS mode.
By Hiroyuki SATOH、Tomoyuki ITOH、Kazuaki TAKIZAWA
Quantification of Static Seating Comfort of Motorcycle Seats
We established a posterior characteristics index (PCI) to quantitatively evaluate static seating comfort of motorcycle seats. This index expresses such characteristics as the shape and size of the posterior as well as the weight of a person. The static seating comfort of motorcycle seats was analyzed using the PCI and seated body pressure distribution data.
As a result, it was found that the contact surface area and level of surface area change in the body pressure distribution data obtained while the test subject was seated are effective indices for static seating comfort common to all test subjects.
By Mitsue KOYANO、Takeshi KIMISHIMA、Kengo NAKAYAMA
Reducing Vibration of A 2-Cylinder Outboard Motor by the Pendulum Motion Mount Method
First-order vibration, which an engine generates, has been isolated by applying the pendulum motion mount method to a 4-stroke 2-cylinder outboard motor. First, the vibration of the outboard motor was theoretically analyzed using a two-dimensional kinetic model. Through this analysis, the theory of isolating vibration using the pendulum motion mount method was established by finding the conditions which isolate vibration effectively. Next, this method was applied to the design of an outboard motor. The mount location was optimized in consideration of both the function and the vibration, and the mount structure was designed in consideration of endurance. The body of the outboard motor was designed by optimizing the vibratory characteristics in order to avoid the resonance. The experimental verification using the newly developed 4-stroke 2-cylinder small outboard motor revealed that the effectiveness of vibration reduction was equal to or better than that of an outboard motor equipped with a first-order balancer.
By Kazuyuki SHIOMI、Takeshi OKADA、Tetsuro IKENO、Michiharu OHKAWA
Development of a Vibration Prediction Technique for Automobile Exhaust Systems
A simulation technique that uses a finite element model for predicting vibration in the exhaust system was developed. The shapes of the flexible tube portions of the flexible joints, or vibration absorption joints, were faithfully modeled and the characteristics of the other parts were assigned numerical values. An accurate model of the ball joints was obtained by assigning numerical values to the dynamic properties of gaskets. The vibration force of the engine, which is the input for this system, was obtained using the sum of the inertial forces of the component parts and the rotational reaction force produced by cylinder combustion pressure. This made it possible to quantitatively predict the forces transmitted to the body from the exhaust hangers and to qualitatively understand exhaust system behavior. This in turn makes it possible to study the optimal locations for the exhaust hangers and the vibration absorption joints in the pre-development stages.
By Hideyuki YOSHIMOTO 、Masato SAKURAI、Hidekazu AKIYAMA、Hiroshi NAKAGAWA、Kazutoshi YUKI
Development of Simulation Technology for the Dynamic Behavior of Crankshaft Systems in Motorcycle Engines
In order to improve durability and marketability of an engine and reduce the development period, crankshaft system simulation technology was developed.
A crankshaft and a crankcase are modeled using the Finite Element Method (FEM). The models and a calculation model of the hydrodynamic reaction force of bearings are linked and the crankshaft behavior is calculated using numerical integration within the time domain. This simulation technology enabled accurate prediction of crankshaft behavior and stress through the high operating speeds that characterize motorcycle engines.
By Tadashi NIINO、Tatsuya IWAMOTO、Shingo UEDA
Establishment of Valve Displacement Measurement by Laser Equipment
In order to precisely analyze valve behavior of an automobile engine valve train, we applied a laser displacement meter. We were able to demonstrate that laser measurements are more precise and that lasers produce less noise than a conventional electro optical displacement transducer. However, when the laser method is applied, such problems as irregular reflection of noise on walls around the measured object, and digital conversion noise that is inherent to laser measurements, were encountered.
We resolved these problems and improved the laser measurement by changing the shape of the measured surface and the surrounding walls to decrease the noise, and through zero point shift of the input voltage.
As a result of reducing the noise, it became possible to precisely analyze valve behavior, and we isolated the rocker arm recollision with the valve due to the delay caused by the rocker arm inertia. Additionally, because the laser is more compact than the conventional optical instrument, it is possible to simultaneously measure multiple cylinders.
By Hisashi KANDA、Motoki TANAKA
Development of a Strength Prediction Technique for Automotive Exhaust Systems
A technique has been devised for predicting the strength of an automotive exhaust system in relation to the rotational force input from the torque reaction force of the engine.
Conventional static analysis conducted using the Finite Element Method (FEM) has been replaced by techniques for dynamic analysis that treat the force input accompanying large transient displacement as a forced displacement, and techniques that take into account the nonlinear nature of mounting rubbers, flexible joints, and so on. As a result, it has become possible to predict the strength of exhaust systems with greater accuracy, and to apply these techniques as development support tools.
By Hiroshi NAKAGAWA、Ayumu ISHIZUKA、Youtarou UKAI、Takumi TAKAKAMO、Masahiko HIGUCHI
Development of a Long Life Continuously Variable Transmission Fluid
With the purposes of making the maintenance interval of continuously variable transmission (CVT) fluid as long as that of automatic transmission (AT) vehicles and of making its use common to AT vehicles, an ester friction modifier and high FW amide were used to develop a fluid that is optimally adjusted to friction characteristics by means of a metallic detergent. This fluid has at least 4 times the longevity of current products with respect to friction characteristics.
The initial vehicle quality such as the shift quality of AT vehicles, which is affected by the friction characteristics of a wet clutch transmission, and acceleration smoothness from stop of CVT vehicles are maintained by this new fluid, which has made it is possible to extend the maintenance intervals of CVT vehicles. Also, the extended maintenance schedule has occasioned improved convenience for the user and contributed to reduction in the amount of liquid waste disposal because of the reduced frequency of fluid change. Therefore, it is expected that this new fluid will contribute to the prevention of pollution of the global environment.
By Yasuo HIRAO、Takashi NAGASHIMA、Tomonori YAMANE、Junpei YOSHIDA
Development of a Long Life Engine Coolant
We have developed a long life engine coolant that has performance equivalent to current coolants with respect to impact on cooling system parts and anti-corrosion performance for extended metal life through the use of organic carboxylate, inorganic oxychloride inhibitors, and other compounds added in appropriate amounts.
Vehicles utilizing this coolant realized maintenance intervals more than two times longer than with current coolant. In addition, this maintenance reduction reduces the amount of coolant waste generated with regular replacement by approximately 70% or more, and makes it possible to reduce disposal costs and incineration volumes.
By Mitsuru OSAWA、Toshiro IJIMA、Takashi NAGASHIMA、Keizou FUKUDA
Development of a Lead-Free Fuel Tank
A hot dip Sn-Zn alloy (8% Zn) coated steel sheet having superior corrosion resistance, formability and processability was developed as a lead-free fuel tank. As soldering material, an Sn-Ag alloy (3.5% Ag) having low temperature soldering characteristics and superior galvanic corrosion characteristics with the coating was developed.
An issue in the production engineering area was that consecutive spot welding quantity declined to 1/2 the number of current welds. The cause was degradation of the electrode caused by an alloy reaction between the metallic electrode and the coated metal. The technical improvement measures to handle this were the surface contact resistance was controlled, the weld current was reduced, and the shape of the electrode tip was optimized.
This enabled attainment of processability equivalent to current levels using existing equipment, and development of a fuel tank having superior corrosive durability, formability and welding characteristics, and overall performance.
By Kazunori TAKIKAWA、Teruaki IZAKI、Yasuo TAKAHASHI、Masayuki NARITA、Yoichi MURAOKA、Yasuji MORIMOTO
Development of a Novel Bumper Adhesion Promoter
A new type of adhesion promoter for bumper painting was developed to eliminate conventional primer spray application. The importance of this new material allowed for reduced cost and improvement in process efficiency. The new adhesion promoter (HX) is a waterborne emulsion incorporating chlorinated polyolefin, a key enabler of adhesion of base coat to thermoplastic olefin. As a consequence of the material design, the adhesion promoter can be applied as a final rinse, resulting in the primer spray application to become unnecessary. Furthermore, the primer spray booth became available for additional topcoat application, increasing production volumes. Overall, this material has proven to meet rigorous testing, and has been successfully implemented in mass production.
By Corky KAMEI、Kazuo IGARASHI、Michael WISEMAN
Development of Weight Reduction Technology for Door Trim using Foamed PP
To reduce vehicle weight, a foaming PP resin was developed as a substrate for the injection molding of door trim. This material was formed by mixing a PP resin that acts as a base with a master batch of foaming agent. The PP resin used as the base is low viscosity to reduce the amount of the injected resin. Non-filled PP resin is also used to lower the specific gravity. Impact-resistance is improved by adding an elastomer. The foaming agent was selected after considering such factors as the uniformity of foam cells, effects on pollution, and the associated work environment. The ratio of foaming agent was selected for a balance between product stiffness and low-temperature impact-resistance. The result is a weight reduction of approximately 25% compared to conventional door-trim substrate material.
By Kenji HIKITA