An ultra capacitor has been utilized as a back up power source to give the Honda fuel cell vehicle acceleration performance rivaling that of a conventional vehicle. To control the difference in voltage between the two power sources at system start-up or takeoff from idling stop, a VCU (Voltage and current Control Unit) has been set between the fuel cell and the high-voltage device for the traction motor. The VCU charges the ultra capacitor gradually by chopping control of the current from the fuel cell equalizing the voltage of the fuel cell and the ultra capacitor. This prevents the occurrence of over-current at system start-up or takeoff from idling stop. When the ultra capacitor is being charged with regenerated braking energy, chopping control of the current from the fuel cell by the VCU electrically separates the fuel cell and the ultra capacitor, and the current from the fuel cell is restricted. This enables the energy provided by regeneration to be utilized for charging the ultra capacitor.

Research on a micro gasturbine generator targeted for a compact distributed energy resource, which would contribute to the improvement of energy usage efficiency, has been conducted. While aiming at a low emission level by introducing a premixed lean burning method, the engine has achieved a generation efficiency of 30.8 and 26.7 percent at the engine and system end respectively by adopting a recuperator and by reducing the heat and mechanical loss specific to its compact structure. Electricity output from the high-speed generator is converted into commercial power and supplied in coordination to the power grid. The engine, inverter and other auxiliary devices have been arranged into one compact package, achieving the highest performance and ambience level in the class (of 40 kilowatts). Further modifications of the engine have improved the efficiency to 32.9 percent at the engine end.

The 4-stroke engine road racer, RC211V, has been developed with concept as “Launching of Honda’s own advanced technology in pursuit of speed and functionality”. Employing a light and compact 4-stroke V-type 5-cylinder engine for the first time in the world, it was aimed to realize linear torque characteristics, easy operational traction characteristics, high controllable handling by mass concentration and better turning ability than 2-stroke road racers. A semi dry sump crankcase utilizing the transmission room for oil tank, and pressure controllable fuel injection system were adopted to achieve the performance target of engine. In addition, the specified minimized weight, 145 kg, for 5-cylinder engine motorcycles was satisfied by employing of a new type of aluminum twin spar frame, a low gravity fuel tank and a Unit Pro-link suspension on the frame body and the suspension, as well as by weight reduction of each part.

The HRX217 lawnmower was developed for general consumer use based on the key concept of maximizing performance in both the bagging and mulching modes of operation. Performance has been increased by the development of a variable mowing system (VMS). The variable mowing system allows the customer to select either the bagging or mulching configuration for their lawnmower by easily rotating a lever. This gives the customer a never before achieved control on the performance of his/her lawnmower. Notably, this is done without the customer having to remove or replace any parts, or use any tools. The VMS technology was also achieved without an increase in cost to the customer over existing mulch plug technology. Lastly, the VMS significantly reduced the overall quantity of grass clippings collected in the bagging mode, therefore reducing the environmental impact of grass clipping disposal.

An experimental hydrogen refueling station using solar radiation has been built in order to propose a solution for energy and global environmental issues. The system total efficiency of 6.5% is achieved by using an electrolyzer with a newly composed catalyst. As a result, it is predicted that this would produce enough hydrogen to drive a fuel cell vehicle for 10 000 miles per year with 8kW capacity from photovoltaic modules. Also, CO₂ emissions for production of hydrogen per unit were reduced to one-fifth by employing a CIGS thin film compound photovoltaic module, as compared with a single-crystalline Si photovoltaic module. The hydrogen refueling station has enabled to demonstrate a form in which future hydrogen production may appear, as well as a design indicating the hydrogen society is coming closer.

Vehicles such as the new Honda Accord PZEV (Partial Zero Emission Vehicle) can help California and other regions achieve their air quality objectives. However, the potential impact of this technology upon air quality is not fully understood by regulators or by the general public, and it has not been accurately quantified. For this reason, Honda has initiated a research center at the University of California, Riverside, for the “Study of Extremely Low Emission Vehicles”(SELEV). There are three interrelated objectives for this center: (1) Measure the emissions of advancedtechnology vehicles under real-world conditions; (2) Build a database of vehicle population and activity; and (3) Use these data to develop air quality models that can accurately assess the impact of near-zero-emission vehicles.

This paper will detail the development and validation of an on-board system capable of determining massbased emissions, and the use of this system to prove that advanced-technology vehicles maintain their emission performance under real-world driving conditions. It will also be shown that data collected during this program can be used to improve the accuracy of emission inventory predictions. The preliminary, encouraging results of this program have been recognized by the California Air Resources Board (CARB), and some of the recent changes in the ZEV regulation reflect the realworld near-zero emission vehicle performance being confirmed in this research program. This program has also received the attention of the national media.

A VTEC rocker arm has been produced from aluminum die-cast materials to reduce weight and lower cost. The new arm, like the majority of rocker arms in use, employs a roller follower to reduce drive friction loss in the valve system. The VTEC connecting holes, in which strength must be guaranteed, were focused on to enable the shift to aluminum in the new VTEC mechanism. A coaxial roller structure with a hollow roller bearing shaft was adopted, allowing the roller shaft to be press-fit into place and ensuring sufficient strength and accuracy in the new rocker arm. As a result, both the weight and the cost of the new rocker arm have been reduced by more than 20% against the former forged steel arm. The new arm was then first mass-produced for use in the Fit.

An oil deterioration monitoring system has been developed to enable the necessary intervals between oil changes to be judged with greater accuracy. The system calculates oil life using an oil deterioration algorithm. When the figure reaches a predetermined value, the meter displays a recommendation for oil change. The algorithm first estimates oil temperature, a parameter of the oil deterioration coefficient. The coefficient and engine speed are then used to calculate how much of the oil’s usable life has been expended. The oil deterioration coefficient, which is dependent on oil temperature, was found from oil life in endurance tests conducted with oil at differing average temperatures. A market survey was conducted to verify the applicability of the measure to a variety of driving modes, and results were reflected in calculations of oil life. It has been demonstrated that this system is successful in enabling U.S. users to change their oil at more appropriate intervals.

An image inspection system has been developed to reduce the time expended on product inspection. This system has been designed for inspection of the elements utilized in CVT steel belts. Images from a CCD camera are automatically inspected on the basis of a quantified grading standard. In addition, a new element transport system which automatically sorts and arranges the elements according to the results of inspection of the images has been developed to specific elements to be sorted out. The use of this system for inspection of CVT elements has reduced the time required for inspection by more than half against the visual product inspection method.

The system, which efficiently adds up parts cost of one vehicle of motorcycle, amid the progress of model development from concept stage to mass production through prototype stage, has been developed. This is characterized by the capability of linlking cost and suppliers' information of mass-produced parts, and parts of new model of Development division, between Manufacturing BOM (Bill of Material) managed by Manufacturing division and Development BOM managed by Development division. This system has been developed with Java, one of the fundamental technologies of webifization. Moreover, such methods has been introduced as lowering the maintenance cost and the load on network, PC clients, to consider the overseas use. Consequently these made it easier to see the cost changes of a new model being developed, and helped to improve operation efficiency in calculating model cost in overseas offices as well as offices in Japan.

A DC brushless motor has been developed as the traction motor for the FCX, the world’s first commercially marketed fuel cell electric vehicle.

This motor is adopted a salient pole type surface permanent magnet (SPM) rotor, which enables both to produce reluctance torque and to minimize the use of magnets, for improving dynamic performance. The inductance value is set at the limit value of enabling output at the maximum rotor speed, which suppresses field-weakening current. The motor, therefore, achieves both high output and high efficiency. The utilization of the magnets enables continuous operation at the maximum rotor speed by suppressing eddy current loss by means of magnet surface insulation and magnet segmentation, and by raising the limit of irreversible demagnetization by means of high coercive force of the magnet material. Strength reliability at high rotor speed in consideration of degradation has been assured by applying the Weibull theory as a method of evaluating the strength of magnets which was formed of brittle material.

The employment of the methods described above has resulted in a maximum output of 60kW, a maximum torque of 272Nm, a maximum speed of 11,000rpm, and a continuous rated torque of 200Nm. In addition, the combined efficiency of the motor and inverter achieves 93% in average of LA4 mode.

For efficiency improvement and miniaturization of electric motor to be equipped in hybrid electric vehicle, lap winding was adopted as winding type of stator and reduction of thickness and loss of the motor was achieved. Three nozzles are utilized to wind from the outer circumference around I-shaped split cores, enabling the length of the braided winding overhang to be minimized, reducing the length of the winding. The use of multi-hole alignment nozzles and a jig for fixing the winding has increased the space factor. In addition, employing a two-step stamping process in which the first load is applied to increase the internal diameter and the second is applied in the axial direction has enabled the height of the winding overhang to be limited to 10mm. These have increased operation efficiency by 7%.

A homogeneous mixing and autoignition prevention of air and natural gas has been simultaneously obtained adopting a multi-venturi composed with a number of dispersely arranged venturi mixers set up as a premixed lean burn combustor. By applying the characteristics of the venturi mixers, a high accuracy prehension of the state of combustion was enabled, and the enlargement of the premixed combustion range was achieved. The combustor system above was installed on a micro-gas turbine, achieving an ultra low emission level of 3ppm (at 15 percent oxygen equivalent) NOx, CO and THC at 50 to 100 percent load.

The demand for reliable, low maintenance, oil-free micro-gasturbine imposes significant demands on the bearing system. The air foil bearing provides low power loss, adequate damping for supercritical operation and long life with oil-free. In this application, foil bearings support a 9.2kg, multi-component rotor operating at 77000rpm with a bending critical speed of approximately 42500rpm. Stable and reliable operation over full speed range on shaft system rig and microgasturbine has been demonstrated.

Soft switching inverter technology was examined as a means of increasing the efficiency and reducing the noise of the inverters used to drive motors in hybrid electric vehicles and fuel cell vehicles. From the various soft switching circuit topologies available, AC link inverters were selected as the research focus, because they can be used in high-power applications and require few additional circuit components. Specifically, single inductor auxiliary resonant AC link inverter was worked out to further reduce the number of inductors. Comparisons with hard switching inverters showed a 0.5% improvement in efficiency. In addition, conduction noise was reduced at almost all frequency bands and radiation noise was reduced at all frequency bands, and demonstrated maximum reductions of 10dB and 20dB respectively.

A 100 Wh flywheel battery was fabricated and demonstrated. Research was conducted on the element technologies of the battery, a carbon fiber reinforced plastic (CFRP) rotor and magnetic bearing control, with the following outcomes. Burst tests conducted on the rotor showed that its achieved strength was more than 80% of the theoretical strength. In addition, 25000 - 50000 rpm (operational speed range) cyclic stress tests carried out at ordinary temperatures demonstrated that the rotor is durable to 30000 cycles without fiber breaking or delamination. The digital processing technique of a speed tracking type band-stop filter for automatic balancing control of magnetic bearing was proposed. It was clarified that the stability of conical forward mode decreases by a gyroscopic effect as speed increases. The control method of magnetic bearing providing low-vibration and stable suspension up to the maximum operating speed of 50000 rpm was established.

The results described above confirm the feasibility of a safe and durable flywheel battery.

Improving engine cycle thermal efficiency is an effective way to increase engine torque and to reduce fuel consumption simultaneously. However, the extent of the improvement is limited by engine knock, which is more evident at low engine speeds when combustion flame propagation is relatively slow. In this paper, computational fluid dynamics (CFD) tools were applied to evaluate the potential for improvement of V6 engine, and effectiveness of various design concepts of engine water jacket by judging surface heat transfer coefficient under isothermal condition. Theoretical considerations were given to optimize the cooling efficiency. Consequentially, engine performance was carried out in base engine and a prototype engine, improvement of engine output and fuel economy was confirmed. Furthermore, a new CFD methodology was developed in which iterative coupling approach was taken to include combustion chamber, water jacket and solid components. Component temperatures were predicted explicitly and compared with measurement results.

An LEV-II compliant catalytic system employing a low precious metal perovskite catalyst has been developed as part of research efforts to contribute to the preservation of the global environment and the conservation of natural resources. Conventional catalyst systems are effective in purifying exhaust gases, but the reduction of the large amounts of precious metals they employ (Pt, Rh, Pd, etc.) is desirable in order to conserve resources.

However, perovskite catalysts containing no precious metals have lower durability and purify exhaust emissions less effectively during warm-up than catalysts with a high precious metal content.

The research described in this paper combined a perovskite catalyst with Honda’s original high-accuracy A/F control and quick warm-up systems, enabling the LEV-II regulations to be cleared and achieving a level of performance with 2g of precious metal catalyst identical to that previously requiring 4g or more.

When AT clutches are utilized in torque-on-demand 4WD systems, in which rear wheel traction is controlled by pushing force from a wet multiple disc clutch, unusual noise is generated in some cases during turning or takeoff by continuous input of difference in speed. The status of lubrication in a clutch unit in isolation was analyzed to find the cause, and results showed that the lubrication flow rate to the clutch was low, and that the lubricant was not being uniformly supplied to every section. A test vehicle was set up to reproduce the conditions of the unit analysis, and the unusual noise occurring in the unit was effectively reproduced. It was determined that the noise is related to the ratio of porosity and the amount of deflection in friction materials. These results enabled the specifications of the lubricant to be improved. In addition, friction materials with increased porosity and deflection were developed to improve the oil retention characteristic in the clutch. Vehicle tests were repeated employing these measures, and no unusual noise was generated.

Waveforms of longitudinal vibration during acceleration in MT vehicles have been used to develop five evaluation indices corresponding to sensory evaluations. The mechanism of longitudinal vibration during acceleration was clarified in each part of the system through which it is transmitted: engine, drive train, tires, engine mounts and suspension. A simulation model was constructed employing design values as the main elements, enabling specifications to be tested in the initial development phase, before the construction of an actual vehicle. This method was utilized in the development of the new model Accord, enabling suspension characteristics and engine torque control, among other design elements, to be optimized at an early stage, and resulting in the reduction of development time by half.

The computer simulation of tilling force has been conducted to a compact walking tractor that equipped with driving wheels and a rotary shaft in its rear and its front respectively to estimate the effect which the tilling force having a down cut rotary and a coaxial counter rotating rotary cause to the behavior and the depth of the tractor. The tractor uses a down cut rotating tine that rotates to the same direction of the driving wheels, and the coaxial counter rotating tines that rotates on the same shaft simultaneously. Further, an actual machine test was conducted to examine the correlation between the estimation and the test result. It was demonstrated that by using the coaxial counter rotating rotary, the effect not only stabilize the behavior of the tractor but accomplish twice the depths of a normal rotary’s can be obtained.

Carbon adsorption was selected as a means of efficiently storing methane, the main component of natural gas. Simulations were first employed to determine an ideal adsorptive pore structure. The results of the simulations were established as a target in the manufacture of activated carbon, with coconut shell, coal and carbon nano-materials (Buckminsterfullerene, carbon nano-tubes) as starting materials. TEM analysis confirmed that the activated carbon produced in this research possessed the ideal pore structure established as a target. This activated carbon is capable of storing 0.155NL/cm³ of natural gas at low pressure (3.5MPa). This represents 77.5% of the capacity of high-pressure (20MPa) compressed natural gas (CNG) storage. The material’s storage capacity for adsorbed methane gas is in the world’s top class of presently reported figures.

In order to enhance engine performance of racing motorcycles, aiming increase of critical engine speed, a valve spring retainer made of lightweight powder aluminum alloy has been developed. The high strength abrasion resistance aluminum, “NCP 400” (Nano Crystal Powder metal with crystal grain size of 400nm), hard grains are blended with optimum amount to get abrasion resistance to Nano Crystal Powder aluminum alloy consisted of Nano-sized crystal grains, was created. Optimum temperature control and forging method for the material property established the warm-precision-closedforging technology that post-machining is unnecessary in parts manufacturing. Verification method of safety factor was set up, by which the load of retainer could be evaluated quantitatively based on the movement of valve train during operation.

SUS301-EH is widely used as a material for exhaust system gaskets, however, at temperatures in excess of 400°C, it can not be used as gas-seal ability of the material declines due to its reduced hardness. The following methods were found to be effective in controlling the softening of stainless steel at high temperatures: (1) addition of N; (2) Stabilization of austenite structure; (3) addition of Mo. The addition of 0.5% N to austenitic stainless steel containing Mo has enabled the speed of softening at high temperatures to be significantly reduced, due to strain aging by solid N below 600°C and the combined effects of precipitation hardening and control of growth of recrystallized grains through the precipitation of fine Cr₂N on the dislocations and the grain boundary above 600°C. A high-heat-resistant spring material has been developed which shows no reduction in hardness up to at 600°C, which is higher by 200°C or more compared to conventional materials. The application of this material to exhaust gaskets has enabled the achievement of excellent seal performance even in tightened sections in hightemperature environments of 400°C and above, which was problematic for conventional gasket materials.

A high fatigue strength and wear resistance induction hardened crankshaft has been developed for diesel engines. Crankshafts for use in diesel engines must be engineered to tolerate the high loads generated by high in-cylinder pressures, and be capable of resisting wear caused by the carbon which collects in the lubricating oil as a combustion by-product. Simultaneous hardening of the shaft and the fillet has been adopted in the newly developed crankshaft to achieve high strength while reducing the number of production processes, resulting in the development of a crankshaft with excellent fatigue strength, resistance to wear, and mass producibility. A special material was developed for the crankshaft to enable the curvature occurring during induction hardening of the fillet to be easily corrected. In addition, control of inclusions in materials has enabled the lead component, conventionally added to increase machinability, to be removed without sacrificing workability.

Many different types of bolts are employed in automotive applications for a variety of different purposes and uses, and their strength generally ranges from 700 N/mm² to 1200 N/mm². The present increasing focus on increasing fuel economy to prevent global warming has led to the requirement to increase the strength of bolts in order to lower weight. However, increasing the tensile strength of conventional bolts increases the incidence of delayed fractures, and is therefore not suitable for mass-market vehicles. This project studied the use of high carbon steel rods, which are less susceptible to delayed fracture than conventional bolt materials, as a solution to this issue. The difficulty of heading when employing high carbon steel rods was solved by improving the material through the addition of the optimum amount of Cr, utilizing a new forming method in which the spindle is hardened during heading, and adopting a hexalobular shape with excellent formability. The application of these techniques made it possible to form bolts from high carbon steel rods, and has enabled the development of a 1 600 N/mm² class high-strength bolt. The new material and techniques have been used in the manufacture of the conrod bolts used in 2003 models, and have enabled the size of the bolts to be reduced from conventionally used M12 to M9, and the weight of individual bolt to be reduced by 80g.

An organ-type pedal attached to the floor by a pivot has been developed to increase the comfort of accelerator pedals. The trace of the new pedal is in the same phase as the motion of the sole of the human foot.

Tests on a plastic hinge structure for the pivot was conducted. Results showed that polyester elastomer possessed superior fatigue resistance, and this was therefore selected as the hinge material. Newly developed thin hinge has enabled the new pedal to equal conventional pedal structures in strength and durability. The hinge section was immersed in oil, grease and other chemical agents to test durability, and results showed no change in physical properties.

The connection of the pedal to the floor was also altered. The flexibility of the material has enabled snapfit assembly, and the connection is sufficiently strong to resist an extraction load of over 900N.

The steering wheel is the interior component which is touched with the highest frequency. To improve the feel of the steering wheel, this project developed a soft in-mold paint which enables a soft-feeling design to be added in the existing in-mold painting method. The target was to achieve the feel of aniline leather, which is the most pleasant leather to touch. Equipment measuring the sense of friction was utilized to obtain values for friction to which a standard deviation was applied, enabling measurement of softness and the sense of grip necessary for steering. The use of a combination of soft polyester resin and urethane resin beads in the paint mixture and a soft-type polyester-denatured hexamethylene diisocyanate (HMDI) as the hardener has given the paint a very soft feel.

Active noise control technology for booming noise has an issue in a balance between cost and performance, because it needs expensive high-performance processor as DSP for the purpose of many convolution operations. As a result, there are few applications of this type of technology to reduce booming noise.

The purpose of this paper is to propose a new algorithm significantly reducing the amount of arithmetic operations by focusing on the fact that booming noise is a narrow band noise. This algorithm enables us to employing inexpensive controller although adaptive signal processing is utilized. Also, the integration of this system with an audio system further improves the balance of cost and performance.

The system developed in this study has been applied in combination with an active control engine mount system to reduce booming noise generated in threecylinder operation by a new model vehicle fitted with a new V6 engine provided with cylinder on demand, resulting in the achievement of excellent fuel economy and NV performance.

An active control engine mount system has been developed to control noise and vibration in a completed vehicle employing a 3-liter V6 cylinder-on-demand engine. The research described in this paper focused on the fact that engine vibrations caused by fluctuations in torque can be estimated from fluctuations in crank revolution, and developed a new fixed feed forward control algorithm which does not employ sensors such as a load cell or an accelerometer. A higher responsive low-heat linear solenoid actuator has been developed for use in the system, and its unique coupling structure with an excitation plate inside the hydraulic engine mount makes it extremely reliable. The results show that noise and vibration performance at three-cylinder drive is equivalent to that obtained at full-cylinder drive.

Isolation rubber parts with hydro structures have low dynamic stiffness and high damping, and also allow high degrees of freedom in setting the required characteristics. The project discussed in this paper studied the methods of utilizing these advantages in suspension bushes in order to improve ride comfort and reduce road noise.

With regard to the harshness experienced when driving on a stepped road, the inputs are in phase for the left and right tires in the majority of cases, and this phenomenon formed the focus of this study. Hydro bushes with different characteristics for the right and left sides were used to generate phase differences in the transmission powers to the chassis, enabling the development of a method of countering the transmission powers on the left and right sides. This method has enabled the transmission powers in the chassis on stepped road to be reduced.

Tire vibration when driving on rough paved road is transmitted to the cabin through the suspension. It was discovered that considerations of the rubber bush in the suspension system as a spring element and a damping element, and of the arm as a rigid body element and a elastic element, were important factors in the reduction of road noise. Optimization of the hydro bushes on this basis enabled the level of road noise experienced in the cabin to be reduced.

Cabin noise originating in the power plant has been reduced by utilizing non-combination type dynamic dampers to reduce the absolute value of the complex spring coefficient of the engine mounts in the highfrequency range.

Development first employed simulations, which demonstrated the superiority of the non-combination type to the combination type dynamic dampers. Next, study focused on how best to exploit the structural characteristics of non-combination type dynamic dampers to enable them to be applied to the rubber parts of the engine mount. Single non-combination type dynamic damper units have been shown to control increases in the absolute spring coefficient caused by rubber surging and mount bracket resonance. Cabin noise in a completed vehicle has been also reduced. Finally, it has been confirmed that the targeted durability can be kept even with the use of the dynamic dampers on the rubber parts of the engine mount.

In a development of sound isolation type generators, three-division case object structure that has divided two cool zones and one hot zone was newly studied. This study was aimed at establishment of compatibility at high level between sound isolation and cooling capabilities that are in a trade-off relationship. Sound isolation of 12.1dB(A) was achieved according to this structure, securing the equivalent level of cooling capabilities to that of open frame type generators. As a result of adopting the new structure to the generators for domestic consumption for India, the Indian noise regulation phase II has been accomplished for the first time in the entire world.

Rectangular-shaped radiators for motorcycles have been used previously in many cases. According with the latest high-power engines, to use arbitrary-shaped radiators is increasing to get high heat radiation within limited space. This type radiator has different cooling tube length. It is more difficult to predict heat radiation amount for this type than rectangular type as velocity distribution is uneven. Moreover, analysis regarding heat radiation characteristics has not been done sufficiently and dependency of flow amount on heat radiation has been unclear. By combining calculations of threedimensional flow field and one-dimension heat radiation, a method that can predict heat radiation amount of arbitrary-shaped radiators easily and precisely has been constructed.