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Composite bearings of PTFE as the base material have been widely used for automotive parts. However, in recent years, due to downsizing, faster sliding speeds, and tendency to increase the bearing load with high performance, particularly for boundary lubrication conditions, the PTFE-based composite bearing is often worn, making it difficult to apply to some applications. A high strength polymer was selected as an alternative to PTFE base material, and the mechanical properties and performance in a start-stop test, reciprocating sliding test and seizure test were evaluated. Focusing on the characteristics of high strength, by applying a PEEK resin, in each evaluation, it was confirmed that superior performance was achieved compared with a conventional PTFE based composite bearing. Presenter Yohei Takada, Daido Metal Co., Ltd.

Recently, automotive engines have been operating under harsh conditions of high-power, low viscosity oil and increase of start-stop (e.g. idling stop). In plain bearing used within engine, as oil film thickness decreases, the frequency of direct contacts on the sliding surfaces between the shaft and the bearing are gradually increasing. In fact, the plain bearings for engines would tend to be used under mixed lubrication and the contacts of the surface roughness asperities sometimes occur between the shaft and the bearing. As a result, the bearing wear on the sliding surfaces is accelerated by the contacts of the roughness asperities. In order to predict the bearing performance exactly, it is very important to understand the change progress of the geometric shape of sliding surfaces caused by the wear.

As the recent automotive engines are designed for higher performance, the rotating speed of the engines have been increased drastically. Therefore the engine bearings should be further improved to have better anti-seizure and wear properties under the high temperature at the high rotating speed. The authors have analyzed the necessary functions of the three layers copper-lead bearings at such operating conditions, and then improved and developed the overlay and the copper based bearing alloy with steel back. Physical and chemical properties for this new bearing were studied. Then the bearing performance tests were carried out including the high speed seizure tests and engine tests. From these test results, it was confirmed that this new bearing could be applied for the recent very high speed automotive engines.

A high reliability and low cost temperature sensor for motor vehicle has been developed. The principle of measuring temperature is based on the NTC thermistor. And novel production techniques for sealing and electric connection are presented.

This research proposes an automatic measuring method for the impulse noise of the valve system in engine production line. This research is composed of the following two parts. (1) The most suitable method for indicating the impulse noise of the valve system - the representative characteristic values - is selected from the general measuring methods for impulse noise. As the result, the crest factor in the frequency band above 1kHz became optimal. (2) By detailed sensory characteristic analysis it was found that impulse noise can be heard better with increasing frequency and that there is little influence in the frequency band with the same frequency as the background noise. Thus the crest factor was obtained for each frequency, and the sensory test for the impulse noise of the valve system is deduced by this linear coupling. As the result of multiple reguression analysis, a high accuracy prediction equetion with a multiple correlation coefficient of 0.91 has been obtained.

A new experimental method, that enables to estimate the body and driveline sensitivity to unit transmitting error of a hypoid gear for automotive rear axle gear noise, has been developed. Measurements were made by exciting the tooth of the drive-pinion gear and that of the ring gear separately using the special devices designed with regard to simulation of acceleration and deceleration. The characteristic of this method is to estimate the forces at the contact point of the gears. Estimation of these forces is carried out under the condition that the higher stiffness is provided by the tooth of the drive-pinion gear and that of the ring gear, compared with the stiffness of the driveshafts and that of the propeller shaft etc., and relative angular displacement of the torsional vibration between the teeth of the drive-pinion gear and those of the ring gear is constant.

The authors, et al. have succeeded in the practical application of the abradable flame spray coating, used in aircraft engines for the prevention of air leakage and the improvement of efficiency, to automobile turbochargers for the first time in the world. Two layers consisting of a bond coated layer and an abradable layer used to be coated by separate spray nozzles under the conventional technique. In this paper, equations of relations between various flame spray coating conditions and the quality of coated film, which were derived from measured results, will be described. Flame spray coating conditions, that allow the double layer coating by the same spray nozzle, have been determined for each layer. Temperatures and speeds of the flame were measured by means of two-color type high-speed cameras, and equations of their relations with the flame spray coating conditions are derived from the measured result.

This paper describes a new plastic coloring and forming system. The system greatly reduces the time and amount of raw materials necessary for color changes, and eliminates the need for manual cleaning during a color change. This system is well-suited for small-lot production with frequent color changes, as well as for automated production systems. The system is being used by auto parts makers, and is practical in a variety of other fields involved with the coloring and forming of plastics.

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.

Oil film thickness is one of the most important issues for optimization of bearing design. A technique has been developed to measure oil film thickness by noting the change in capacitance between the shaft and a thin-film electrode of several micrometers thickness formed on the surface of a bearing. The authors applied this technique to the main journals of an automobile engine and measured the oil film thickness up to maximum speed and full load. The oil film thickness became thinner with increased engine load, and then turned thicker with increased engine speed.

Fuel efficiency improvement measures are focusing on both cold and hot conditions to help reduce CO2 emissions. Recent technological trends for improving fuel economy such as hybrid vehicles (HVs), engine start and stop systems, and variable valve systems feature expanded use of low-temperature engine operation regions. Under cold conditions (oil temperature: approximately 30°C), fuel consumption is roughly 20% greater than under hot conditions (80°C). The main cause of the increased friction under cold conditions is increased oil viscosity. This research used the motoring slipping method to measure the effect of an improved crankshaft bearing, which accounts for a high proportion of friction under cold conditions. First, the effect of clearance was investigated. Although increasing the clearance helped to decrease friction due to the oil wedge effect, greater oil leakage reduced the oil film temperature increase generated by the friction.

Detergent additives in automotive gasoline fuel are mainly designed to reduce deposit formation on intake valves and fuel injectors, but it has been reported that some additives may contribute to CCD formation. Therefore, a standardized bench engine test method for CCDs needs to be developed in response to industry demands. Cooperative research between the Petroleum Association of Japan (PAJ) and the Japan Automobile Manufacturers Association, Inc. (JAMA), has led to the development of a 2.2L Honda engine dynamometer-based CCD test procedure to evaluate CCDs from fuel additives. Ten automobile manufacturers, nine petroleum companies and the Petroleum Energy Center joined the project, which underwent PAJ-JAMA round robin testing. This paper describes the CCD test development activities, which include the selection of an engine and the determination of the optimum test conditions and other test criteria.

Properties of engine bearings were investigated with different bearing materials and different HTHS viscosity oils by means of both an engine test and a rig test. The rig test well simulated the bearing wear which occurred in the engine test. Lead-bronze bearings with lead-tin-indium overlay gave the least amount of wear in operating under high speed and heavy load conditions even with low HTHS viscosity oil. Aluminum bearings without overlay gave good wear resistance in the case of no seizure occurrence. The wear amount of bearings were well correlated with HTHS viscosity, not with kinematic viscosity.

A new compact five-speed automatic transmission (A650E) has been developed for front engine rear wheel drive cars. The development of this transmission has been aimed at improving fuel consumption, power performance, engine noise reduction during highway cruising and smooth acceleration by employing a wide range of gearing and close gear ratios. Generally a five-speed automatic transmission is larger than a four-speed, because of additional friction elements and gears. This can result in a change in the floor panel of the car body. However, by removing a one-way clutch for second gear and employing a unique gear-train layout, this transmission has the same circumference and length as the conventional four-speed automatic transmission (A340E)(1).1 In order to reduce first or second gear noise, gear specification and supporting structures of planetary gears have been optimized by FEM analysis.

With the recent improvements in automotive engine performance, the operating conditions for the cylinder head gasket are becoming more critical. Today's cylinder head gasket is required not only to ensure high durability, but also to contribute to improving engine performance. This paper introduces a new metal cylinder head gasket consisting of two beaded plates and a thin sheet in-between. Because of the thin sheet, this gasket has several superior characteristics for open decked aluminum cylinder block engines. Sealability and durability were significantly improved.

Toyota has developed a new system, which uses integrated control of powertrain by PowerTrain Management (PTM), in order to improve driving comfort and reliability. This system is currently in use on Lexus's new LS460. This system is composed of 4 parts: a generation part, a mediating part, a modification part and a distribution part. In each part, processes are based on drive power and torque. In the generation part, requests from a programmed model driver, Driving Support Computer and Vehicle Dynamics Integrated Management (VDIM) are generated and expressed by drive power. In the mediating part, most suitable vehicle drive power was selected among the requests. In the modification part, the selected request is modified using a programmed powertrain model, which considers internal combustion engine condition and powertrain response and transmission's tolerance. In the distribution part, optimized engine torque and gear ratio are processed.

Toyota has developed the world's first 8-speed automatic transmission (AA80E) for RWD automobiles. The transmission will first be used in the all-new Lexus LS460. In addition, a novel control system has been developed to maximize the predictability, response, efficiency, and initial quality of the powertrain while utilizing the high number of gear steps.

A newly developed bearing is a lead-free aluminum alloy bearing with low frictional layer which consists of molybdenum disulfide in thicknesses of sub-micron levels on the bearing surface without required binders such as resin. The new bearing had a 50% lower static friction coefficient compared to the conventional aluminum alloy bearing, and exhibited comparable anti-seizure property and fatigue strength to the conventional bearing by evaluation of rig tests. These rig tests verified that the new bearing showed excellent frictional reduction properties. This paper describes details and performances of this newly developed bearing.

The purpose of this study is to analyze con-rod bearing lubrication under reduced oil supply rate conditions. An engine was modified to measure the oil supply rate to a con-rod big-end bearing. Then the effects of the oil supply rate on bearing temperatures and the contact between a journal and a bearing were investigated in order to analyze lubrication characteristics. The bearing temperatures increased in accordance with reduced oil supply rate. On the other hand, the contact frequency hardly changed under almost all conditions, but steeply increased near one-third of the standard oil supply rate at the highest speed of 5000 rpm in the experiments. The results show that the reduced oil supply rate decreases the cooling effect but the hydrodynamic lubrication was sufficiently achieved except the above-mentioned severe condition.

We urgently need to develop the next generation of automotive technology to support energy conservation and the global environment. For this we need an advancement of the Laboratory Automation System (LAS). However, restructuring the hardware and software of the LAS requires enormous amounts of time and costs. To solve the problems of the LAS development, we formed a user-vendor working group, which then established the common rules of LAS and IMACS (Integrated Measurement And Control System). IMACS are software-centered rules, characterized by the stratification of LAS and the interface called software parts. So far, we have integrated IMACS into five engineering fields. A total of 11 testing machine vendors participated in the development. We manufactured about 350 software parts and made their specifications openly available. As the next step, we are collecting software parts by deleting redundant functions.