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This paper proposes a new multi air gap motor with trench-shaped coil. The proposed motor has high torque without rare earth magnets compared to conventional single air gap motors due to its multiple air gap and ferrite permanent magnet (PM) assisted segment rotor poles. Firstly, the basic structure and features of proposed motor is shown: three stator cores, integrated a set of three phase windings, and an annular rotor core with magnetic saliency at three sides and ferrite magnets. Then, the performance of proposed new motor and well-known single air gap IPMSM with rare earth magnet are compared by FEA. Secondly, the simple winding method similar to the conventional motor is clarified. Next, practical design of the 3-D magnetic circuit with laminated steel is discussed. Eddy current generated by the magnetic flux passing through the laminated steel in the core stacking direction is focused, and methods for reducing eddy current loss are shown.

The need to improve fuel consumption by saving the weights of automobile parts is growing from the viewpoint of global warming mitigation. In the case of a throttle body for controlling the air flow volume into an engine, it is important to achieve a high dimensional accuracy of the valve-bore gap in the state of closed valve. In fact, most throttle bodies are made of precision-machined metal. Therefore, resin throttle bodies are drawing attention as a lightweight alternate. However, in comparison with metal throttle bodies, resin throttle bodies have two potential disadvantages that should be solved prior to productization. The first one is greater air leakage in the state of closed valve, and the second one is smaller heat conduction for unfreezing the valve in a frigid climate. We have developed an electronic resin throttle body that has overcome the above-mentioned disadvantages.

The hole diameter of injection nozzles in diesel engines has become smaller and the nozzle coking could potentially cause injection characteristics and emissions to deteriorate. In this research, engine tests with zinc-added fuels, deposit analyses, laboratory tests and numerical calculations were carried out to clarify the deposit formation mechanisms. In the initial phase of deposit formation, lower zinc carboxylate formed close to the nozzle hole outlet by reactions between zinc in the fuel and lower carboxylic acid in the combustion gas. In the subsequent growth phase, the main component changed to zinc carbonate close to nozzle hole inlet by reactions with CO₂ in the combustion gas. Metal components and combustion gases are essential elements in the composition of these deposits. One way of removing these deposits is to utilize cavitations inside the nozzle holes.

This paper presents the oil circulation behavior in a CO2 climate control system operating at low evaporating temperature down to -32°C. The increase of oil circulation ratio (OCR) from 0 to 6 wt.% during steady state conditions degrades the coefficient of performance and cooling capacity by 15% and 8%, respectively. The pressure drop across the heat exchangers increases, especially in the gas cooler. In low temperature CO2 systems some fluctuations of oil and refrigerant flow rates were observed during cyclic operations when the system did not equip the oil separator, but was observed only at high oil charge when the system did equip the oil separator. These instabilities lead to a periodic compressor performance fluctuation, which caused system performance degradations. Therefore, the use of an oil separator is recommended for the low temperature operation if an ordinary metering valve is adopted as an expansion device without any special control strategy.

CFD has been actively applied for developing automotive air conditioning system in recent years. In addition to automobile interior air conditioning, an automotive air conditioning system has the important function of providing a clear field of view by defogging (or defrosting) the windows. Although many CFD application methods have been reported for estimating windshield defogging pattern, few examples of simulation show accurate result of transient clearing pattern. To predict transient clearing pattern accurately, using a correct model of window glass fogging-clearing is important. As the result of our observation on fogged glass surfaces, fogging was found out to be an aggregation of water drops, so that new dropwise condensation-evaporation model was developed and applied. Transient defogging patterns were simulated with the CFD code including this model, and accuracy was verified on a simplified compartment model and actual automobiles.

The automotive industry has increasingly been focusing its efforts on vehicle part weight reduction, with the aim of improving fuel efficiency as an environmental protection measure. As part of these efforts, the industry has actively been developing plastic pulleys to replace conventional steel pulleys. Of the various pulleys used in vehicles, the air conditioner (A/C) compressor pulley is exposed to the harshest working environment. We therefore investigated towards development of a plastic pulley for A/C compressor application. Required material properties were first identified on the basis of required product characteristic values. As a result, a phenolic resin material was developed that is superior in heat resistance one of the most important properties among those identified. Using the material, we succeeded in developing an A/C compressor plastic pulley, achieving approximately 50% weight reduction compared to conventional steel pulleys.

In preparation for compliance with California's SULEV standard and Euro STAGE 4 standard, which will take effect in 2002 and 2005, respectively, we have developed a laminated planar oxygen sensor. The developed sensor has the following characteristics: high thermal conductivity and superior dielectric characteristic, due to direct joining of the heater element alumina substrate and the sensor element zirconia electrolyte; low heat stress at temperature rise, due to optimized heater design; superior sensor protection from water droplets, and improved sensor response, due to optimized arrangement of intake holes in the sensor cover. With these characteristics, the developed oxygen sensor can be activated in 10 seconds after cold start. This report describes the technologies we used to develop the early-activation oxygen sensor.

In recent years, concern among car users regarding air quality has been steadily increasing. Pollen and diesel vehicle exhaust gases entering the cabin and smoke from fellow passengers not only reduce the quality of experience for everyone in the car, but are also harmful to the health. Therefore, we developed: 1 A low pressure loss, dust-removing, selectively deodorizing filter that effectively absorbs malodor from diesel vehicle exhaust gas, without affecting A/C performance. 2 An automatic intake door control system that excludes outside exhaust gas 3 An optic catalytic air purifier with germ removal and long life deodorizing functions. We here report on the system combining these functions.

In the field of automotive gasoline engines, new products aiming at greater fuel economy and cleaner exhaust gases are under development with the aim of preventing environmental destruction. Severe ignition environments such as lean combustion, stronger charge motion, and large quantities of EGR require ever greater combustion stability. In an effort to meet these requirements, an iridium plug has been developed that achieves high ignitability and long service life through reduction of its diameter, using a highly wear-resistant iridium alloy as the center electrode.(1)(2) Recently, direct injection engines have attracted attention. In stratified combustion, a feature of the direct injection engine, the introduction of rich air-fuel mixtures in the vicinity of the plug ignition region tends to cause carbon fouling. This necessitates plug carbon fouling resistance.

Recently, there is a need for new applications of pressure sensor, such as direct fuel injection systems for protecting the environment, or power assisted brake systems for improved driving safety. For these widening areas of application, pressure sensors with higher accuracy, a wider pressure-sensing range, and integration of sensor chip functions are required. This paper discusses our development of automotive semiconductor pressure sensors.

From the view of suppressing the global warming and environmental pollution, responding to the regulation of fuel consumption and exhaust gases along with lengthening the maintenance interval, are becoming more demanded. The development of a high-performance, long-life spark plug has become essential in response to these demands. While improved performance (high ignitability and low required voltage), the discharge part of the spark plug needs to be reduced in size. But, in the past this has been difficult because of the limitations of platinum alloys in terms of wear. Therefore, it has been quite difficult to achieve both smaller discharge parts and longer life. To dramatically improve wear resistance, we researched materials that are both resistant to oxidation and have a high melting point. This research resulted in our development of a new iridium alloy (Iridium-10wt%Rhodium).

By focusing on light weight and high coatability, a substrate has been successfully developed that has strong and stiff walls but does not sacrifice porosity. For increasing the isostatic strength, outermost cells of substrate are thickened more than inner cells. Furthermore, for preventing the front section of substrate from abrasion by strong deflected exhaust gas flow or contamination, only several millimeters of the front section are stiffened. This reinforced substrate is stronger and stiffer than the low porosity's one, and its coatability is as same as the current substrate.

The development of new systems to reduce exhaust gases is being investigated in response to OBD-II regulations and regulations all over the world relating to the introduction of low exhaust gas vehicles (LEV, ULEV, STEP3, STEP4). We have developed a highly responsive thermistor type catalyst temperature sensor that is very accurate, highly heat resistant, has a wide detection range, and that can be used in exhaust gas cleansing systems. The key technologies used in this new catalyst temperature sensor are: 1 Wide detection range: The thermistor is of a network construction that comprises a semi-conductor with a new Y-Cr-Mn perovskite crystal structure and an insulator. The temperature range can be set by changing the proportions of semi-conductor and insulator.

To improve the performance of the air conditioning evaporator, we have Introduced unique refrigerant circuit. This circuit has refrigerant paths for both upstream and downstream air, and these paths are overlapped to provide uniform temperature distribution at the cooling air side. In addition, the fin pitch has also been minimized by establishing a drainage improvement technology. These technologies have made a great contribution to minimizing the core depth of evaporators.

In recent years, the use of acrylic rubber has grown because of improved low temperature performance and heat resistance. Acrylicrubber is now being adopted as a replacementof NBR because it has good oil and heat resistance. One special feature inherent toacrylic rubber is that if it is in contact withmetal, upon heating, it will adhere to the metal. This adhesion would not be a problem with a fixed O-ring; however, in the case of an oilfilter (O/F) gasket which is regularly changed,the rubber which remains due to adhesion couldbe problematic for sealing. In the past, this problem was overcome by utilizing a coating, such as silicone, on the rubber surface, although this adds another step to the rubber process. Therefore, we developed a new method to prevent the adhesion of acrylic rubber by analyzing the mechanism by which the acrylic rubber adheres to a metal surface.

The recent progress of electronic control systems in vehicles is remarkable as evidenced by the development of electronic fuel injection systems,(EFI), automatic transmission control systems, and anti-lock brake systems,(ABS). The number of actuators for the systems has been increasing. Consequently, a need has been identified for a reduction in volume and number of the system actuators for control purposes. A composite magnetic material has been developed with the aim of miniaturizing magnetic solenoid valves for actuator applications. A composite magnetic material is such that both ferromagnetic and paramagnetic sections coexist within a single material, and can contribute to optimization of the magnetic circuit of a solenoid valve. This paper describes the development of a composite magnetic material, and its resultant characteristics.

The important problems to be tackled from the point of view of preventing global warming are to save the power consumption of car air conditioning systems and reducing the refrigerant used in those systems. Our approach to the task is to enhance system efficiency by utilizing sub-cooling at the outlet of the condenser and also to reduce the amount of refrigerant through a refrigerant behavior pattern analysis. This approach has created a simple system construction using an integrated condenser/receiver device.