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Aluminum Honeycomb Sandwiches and Extrusions have been applied to a platform for convertibles. The platform, composed of a dashpanel and floor panels (honeycomb sandwiches) and a framework (extrusions), has a much more lightweight and rigid structure than other conventional convertible bodies-in-white. This improves remarkably vibrational behavior and handling characteristics, which deteriorate in a convertible, in the case of a prototype.

The U.S. Federal Emission Standards ruled that particulate emissions from '87 models should be no more than 0.20 g/mile for passenger cars and 0.26 g/mile for light-duty trucks. A complete ceramic swirl chamber with a heat insulating air gap has been developed to meet the above standards without sacrificing fuel economy or power output. The whole process by which the ceramic swirl chamber was developed will be described: optimization of materials, design, manufacturing, and the method and system of quality control. The results of long term durability tests will be described, which demonstrate the chamber's excellent reliability.

Disk brake rotors require reduced unsprung weight and improved cooling ability for improved fade performance. Automotive brake rotors made from aluminum metal matrix composites (MMC) were evaluated by dynamometer and vehicle tests for the required improvement. The friction and wear performance and the thermal response during fade stops were compared with those of commercially produced gray cast iron (GCI) rotors. It was proved that MMC is a very effective material to replace GCI for brake rotor application, as it reduces unsprung weight and decreases maximum operation temperature of the brake system.

Magnesium has the lowest specific gravity of all metals used for structural members. The application of magnesium for a road wheel leads to improved vehicle handling and drivability because of the reduction of an unsprung weight. The authors have developed new magnesium alloy which shows excellent mechanical properties and attained a magnesium forged road wheel that is 30% lighter than aluminum wheels.

A method was studied for simultaneous zinc phosphating on aluminum and steel surfaces to obtain high corrosion resistance on aluminum surfaces, which conventional phosphatic processing could not provide with sufficient corrosion resistance. Since aluminum is protected by an oxide film on its surface, it has poor processability with zinc phosphating solutions applied to steel. An appropriate quantity of fluoride was therefore added to improve processing, and the coating film, aluminum composition and surface conditions were optimized to suppress filiform corrosion, which is characterized by string-like blisters of paint film starting from a paint defect. In addition, in view of the actual production environment, the corrosion resistance of the ground area made for readjustment after stamping was studied for the optimization of the processing solution.

While basic automobile performance is improving along with the growth of higher value-added features, rapidly increasing use of electrical and electronics systems with complex wire harnesses is becoming a problem. This is bringing the automotive distributed control multiplex system to commercial reality. At present, standardization of protocols is under deliberation by SAE and ISO, and several protocols are being considered as candidates. To select a multiplex LSI having an optional protocol, we have established a method to evaluate automotive distributed control multiplex system from the standpoint of users. The method will permit comparison of various multiplex LSIs including physical layers and their protocols' performance/reliability, while helping clarify their features and areas of applications. It is our hope that through this activity of ours, we will be able to make some contribution to global standardization in the field.

New material and processing technologies were developed for main components of the rotary engine to establish its reliability and durability. The components discussed in this paper are the rotor housing, side housing, and sealing elements. Also described are the material and processing technologies which resolved problems about their strength, rigidity, wear, etc.

The “R26B” 4-rotor rotary engine is a powerplant that brought a Mazda racing car to victory in the 1991 Le Mans 24-hour endurance race. This engine was developed to achieve high levels of power output, fuel efficiency, and reliability, as required of endurance racing engines. This paper describes the basic structure of the engine, including a 3-piece eccentric shaft that represents a major technological achievement incorporated in the engine, as well as other technological innovations employed for the enhancement of the engine's power output and reliability, and for reducing its fuel consumption. These innovations include a telescopic intake manifold system, peripheral port injection, 3-plug ignition system, 2-piece ceramic apex seal, and a cermet coating on the rubbed surfaces of the housings.

Mazda has developed new-generation V6 engines. The new V6 series comprises 2.5-litre, 2.0-litre and 1.8-litre engines. The development objective was to ensure high output performance for excellent “acceleration and top-end feel”, while satisfying “Clean & Economy” requirements. The engines also had to have a pleasant sound. Mazda selected for these engines a short stroke, 60° V-shaped 24 valve DOHC with an aluminum cylinder block. Various techniques are adopted as follows: Combustion improvement and optimization of control to achieve high fuel economy and low emissions Improvement of volumetric efficiency, inertia reduction of rotating parts and optimization of control to achieve excellent “acceleration and top-end feel” Adoption of a high-rigidity, two-piece cylinder block and crankshaft and weight reduction of reciprocating parts to achieve a pleasant engine sound Material changes and elimination of dead space to achieve a compact, lightweight engine

The Wankel rotary engine is more compact than conventional piston engines, but its oil and fuel consumption must be reduced to satisfy emission standards and customer expectations. A key step toward this goal is to develop a better understanding of the apex seal lubrication to reduce oil injection while reducing friction and maintaining adequate wear. This paper presents an apex seal dynamics model capable of estimating relative wear and predicting friction, by modeling the gas and oil flows at the seal interfaces with the rotor housing and groove flanks. Model predictions show that a thin oil film can reduce wear and friction, but to a limited extent as the apex seal running face profile is sharp due to the engine kinematics.

The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. A model of the oil seals is developed to calculate internal oil consumption (oil leakage from the crankcase through the oil seals) as a function of engine geometry and operating conditions. The deformation of the oil seals trying to conform to housing distortion is calculated to balance spring force, O-ring and groove friction, and asperity contact and hydrodynamic pressure at the interface. A control volume approach is used to track the oil over a cycle on the seals, the rotor and the housing as the seals are moving following the eccentric rotation of the rotor. The dominant cause of internal oil consumption is the non-conformability of the oil seals to the housing distortion generating net outward scraping, particularly next to the intake and exhaust port where the housing distortion valleys are deep and narrow.

At present, various communication protocols for an automotive distributed control multiplex system that aims at solving wire complexity and meeting the requirements of high reliability and open system flexibility have been proposed and installed in production cars. The requirements for an automotive distributed multiplex system, especially reliability, flexibility, and economy have been analyzed in detail, and as a result a new communication protocol based on SAE J-1850 has been developed. This paper describes the design philosophy and technical features of the protocol, named PALNET (Protocol for Automotive Local area Network) and the result of evaluation with the experimental system. PALNET covers moderate speed signals in vehicle electrical and electronic system. Main technical features of PALNET are as follows. Introduction of a new acknowledgement method named ANC (Acknowledgement for Network Control) secures high reliability of data communication.

Spot friction welding (SFW) is a cost-effective spot joining technology for aluminum sheets compared with resistance spot welding (RSW) [1]. In this study, coated mild steel was spot friction welded to 6000 series aluminum using a tool with shoulder diameter of 10 mm and welding conditions of 1500-2000 rpm and time of 5 s. Testing showed that tensile shear strength increased as the solidus temperature of the coating on the steel decreased. Microstructure characterizations of steel/Al joint interfaces showed that zinc from the coatings was incorporated into the stir nuggets and that intermetallic phases may have formed but not in continuous layers. Some Al-Zn oxides that appeared to be amorphous were also found in the joint interfaces.

Today, most widely used synchronizer rings (SNRs) are made of brass (brass SNR). The development of superior SNR to brass SNR has been required for both shift feeling and durability, which are two important requirements for SNRs. Carbon-based friction material (carbon material) is selected to develop superior friction material to brass because carbon material is one of the most durable materials for an application of clutch and brake. Carbon material is placed on the friction surface of SNR (carbon SNR). The structure of carbon material, kinds of raw materials and their combination ratio are selected and optimized. The carbon SNR is confirmed to have higher performance than brass SNR for both shift feeling and durability. At present, our carbon SNRs have been introduced into pickup trucks and SUVs in USA.

The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. In order to better understand oil transport, a laser induced fluorescence technique is used to visualize oil motion on the side of the rotor during engine operation. Oil transport from both metered oil and internal oil is observed. Starting from inside, oil accumulates in the rotor land during inward motion of the rotor created by its eccentric motion. Oil seals are then scraping the oil outward due to seal-housing clearance asymmetry between inward and outward motion. Cut-off seal does not provide an additional barrier to internal oil consumption. Internal oil then mixes with metered oil brought to the side of the rotor by gas leakage. Oil is finally pushed outward by centrifugal force, passes the side seals, and is thrown off in the combustion chamber.