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Technical Paper

Study of Anti-Corrosive Property of Engine Coolant for Aluminum Cylinder Heads

Recently, use of aluminum engine parts has increased for fuel economy and power improvements. Aluminum cylinder heads, for example, are currently used in most engines. But, only low performance engine coolants are available for prevention of heat-transfer corrosion of aluminum cylinder heads. The authors have studied a laboratory test method that is able to accurately evaluate the performance of engine coolants for prevention of aluminum cylinder head corrosion. And we have developed the new test method by changing the test specimen temperature higher and the engine coolant temperature lower than the ASTM D4340 test. The new test has been confirmed engine bench test. We evaluated further the performance of many engine coolants of the world for prevention of aluminum cylinder head corrosion using the new test. We have known that there were a lot of poor performance engine coolants in the world.
Technical Paper

Experimental Study on Viscosity-Shear Characteristics of Lubricating Oils

The viscosity of automotive lubricants containing polymers decreases temporarily in the oil films of sliding parts with the increase in shear rate. This decrease sometimes causes surface damages such as bearing seizure and gear pitting. This paper describes the effect of polymers and base oils on viscosity under high shear rate conditions. The viscometer was newly developed to evaluate the viscosity at high shear rates. Shear rate can vary between 105 sec-1 and 106 sec-1. By using the viscometer, the effects of various factors such as polymer type, molecular weight, polar group and concentration on shear viscosity were investigated. The effects of polymer solubility and molecular weight distribution of base oils were also investigated.
Technical Paper

Investigation on Oxidation Stability of Engine Oils Using Laboratory Scale Simulator

The purposes of this paper are to develop a new laboratory oxidation stability testing method and to clarify factors relative to the viscosity increase of engine oil. Polymerized products, obtained from the oil after a JASO M333-93 engine test, were found to consist mainly of carboxyl, nitrate and nitro compounds and to increase the oil viscosity. A good similarity between the JASO M333-93 test and the laboratory simulation test was found for the polymerized products. The products were obtained not by heating oil only in air but by heating oil while supplying a synthetic blowby gas consisting of fuel pyrolysis products, NO, SO2 and air. The laboratory test has also revealed that the viscosity increase depends on oil quality, organic Fe content and hydrocarbon composition in the fuel. Moreover, it has been found that blowby gas and organic Fe accelerate ZnDTP consumption and that aromatics concentration in the fuel correlates with the viscosity increase of oil.
Technical Paper

Engine Testing Comparison of the Relative Oxidation Stability Performance of Two Engine Oils

The relative oxidation stability of two fully formulated engine oils was compared in three testing methods by following the increase in kinematic viscosity of the oil. The purpose of the study was to determine the cause of the completely opposite ranking of the oxidation stability of the two oils that was observed in the ASTM Sequence IIIE engine test and the JASO M333 93 engine test and to determine the degree of correlation the two engine tests had with the field. The study consisted of laboratory oxidation testing, engine testing and taxi field testing to cover the range of conditions from controlled oxidation to actual driving conditions.
Technical Paper

Development of Oxidation Catalyst for Diesel Engine

In developing an oxidation catalyst for reducing diesel particulates, it is necessary to balance two conflicting characteristics. One is high oxidizing activity so that the catalyst can reduce the Soluble Organic Fraction (SOF) efficiency even at low exhaust temperatures. The other is the suppression of sulphate formation at high exhaust temperatures. First it was studied that active metals and coating materials are given effects on the reduction of SOF, the formulation of sulphate and durability, by using catalysts equivalent in composition to the oxidation catalyst for gasoline-engines. Based on these findings, a two-stage catalyst wasdeveloped. It satisfies the two characteristics at a comparatively high levelby slecting materials and optimizing the catalyst composition.
Technical Paper

High Durability of Metal Support for Automotive Catalyst

A metal support for use in an automotive catalyst is exposed to the severe heat cycle brought about by the intermittent flow of a high temperature exhaust gas. Accordingly, the metal support must have high beat resistance(ex. oxidation resistance) and a rigid structure. Therefore, 20% chromium-5% aluminum ferritic stainless steel(containing small quantities of rare earth metals and titanium) is used as a highly beat resistant honeycomb foil in addition to a highly mechanical durable brazing honeycomb structure. This study examined the durability of a metal honeycomb installed in a gasoline engine. Both an engine bench durability test of a manifold converter type metal support which is connected directly to the exhaust manifold of the gasoline engine and a vehicle durability test of an under the floor type metal support were carried out to evaluate oxidation damage of the metal honeycomb as well as its mechanical durability.
Technical Paper

Development of Galvanized Aluminum Alloy Sheet for Body Panels with an Excellent Filiform Corrosion Resistance

Filiform corrosion phenomenon and its prevention method for 5000 series aluminum alloy sheet have been investigated. The painted aluminum alloy sheets were subject significantly to filiform corrosion caused by formation of a mottled and coarse zinc phosphate film during chemical conversion process. On the other hand, galvanized aluminum alloy sheet showed an uniform and fine phosphate film in a brief time and the filiform corrosion resistance was improved markedly. The test results of press-forming and corrosion for the prototype engine hoods made of this newly developed galvanized sheets have revealed a good formability and an excellent filiform corrosion resistance.
Technical Paper

Poisoning Deactivations of Automotive Catalysts by Lead and Phosphorus

The deactivation process of automotive catalysts by lead and phosphoruos were studied. The accelerated poisoning test were performed. The activity evaluation and characterisation of poisoned pellet oxidation catalysts showed the following origin of poisoning deactivations. Lead interacts with active materials and phosphorus covers over catalysts to reduce these catalytic performance. In the case of phosphorus and lead co-existence, the activity decreases rapidly because leadphosphate plugges pores of the support. In monolithic catalysts, highly axial distributions of poisons was obserbed. This characteristic distribution is advantageous for the durability of the catalyst.
Technical Paper

Properties of Zn-Fe Alloy Electroplated Steel Sheets

We have taken notice of Zn-Fe alloy electroplating with an eye to developing new corrosion-resistant steel sheets for automotive use with both cosmetic corrosion resistance and perforating corrosion resistance, and as a result of investigations into its paintability and corrosion resistance over the whole range of its compositions, we have come to a conclusion that steel sheets with two-layer Zn-Fe alloy electroplating that consists of a thin upper layer with a 75 to 85% Fe content and a lower layer with a 10 to 20% Fe content is the best choice.
Technical Paper

Analysis of the Deterioration of Nylon-66 Immersed in GTL Diesel Fuel Part 1. Analysis and Test of Nylon and GTL Diesel Fuel Before and After Immersion

The effect of GTL diesel fuel on organic materials used in fuel delivery systems of vehicles was investigated. Specimens made from 16 kinds of organic materials were immersed in GTL diesel fuels synthesized at Refinery-A and Refinery-B (referred to as GTL-A and GTL-B, respectively) and then subjected to tensile testing. The tensile test results revealed that elongation of the nylon sample immersed in GTL-A was extremely small, about 4% of that of untreated nylon. In the light of this finding, the GTL diesel fuels and nylons before and after immersion test were analyzed in detail using about 20 analysis methods to determine the cause for poor elongation. The following points were found. (1) GTL-A consisted of low molecular-weight paraffins. (2) GTL-A had low molecular-weight i-paraffins. (3) The nylon immersed in GTL-A contained low molecular-weight paraffins. (4) The paraffins in the nylon immersed in GTL-A were richer in i-paraffins than the original GTL-A.
Technical Paper

Analysis of the Deterioration of Nylon-66 Immersed in GTL Diesel Fuel Part 2. Analysis of Model Fuel and Nylon Before and After Immersion

In a previous paper (Part 1 of this series), nylon-66 specimens were immersed in two GTL diesel fuels (GTL-A and GTL-B) and then subjected to tensile testing. The tensile test results revealed that the elongation of the specimen immersed in GTL-A was dramatically reduced. The GTL diesel fuels and nylon specimens before and after immersion were analyzed to determine the cause of the decline in elongation. It was found that the poor elongation was caused by penetration and oxidation of low molecular-weight paraffins and that the ease of penetration and oxidation of paraffin depended on the structure of paraffin. In this paper, the low molecular-weight paraffins detected in GTL-A were mixed to produce model fuels. Then, pieces of nylon cut from the tensile test specimen, were immersed in the model fuels. In addition, partial oxidation products of the paraffin (alcohol, aldehyde or ketone and acid) were used in immersion tests of the nylon pieces.
Technical Paper

Development of Pitting Resistant Steel for Gears

Newly designed gears are subject to higher loads that demand a steel that is capable of greater pitting resistance. The application of shot peening to gears has been increasing to improve tooth root strength, but pitting resistance had not been necessarily high. This study examines the effect of alloying additions mainly on tempering resistance and the formation of a non-martensitic layer. The developed high Si-Mo type steel shows excellent pitting resistance, even in shot peened gears, as compared to that of conventional steels due to high tempering resistance and the thin, uniform non-martensitic layer. This new steel is of practical use in some multi-speed automatic transmission gears.
Technical Paper

High-Reliability Low-Cost Gold Plating Connector

The authors developed a high-reliability low-cost gold-plated connector for automobiles. The connector is covered with three plated layers, nickel, palladium-nickel alloy, and gold. The three-layer plating helps to reduce the required thickness of gold. This paper describes the reasons why palladium-nickel plating was adopted and compares the corrosion resistance, oxidation resistance and wear resistance of three-layer-plated materials with those of conventional gold-plated materials. In addition, the characterisitics of three-layer-plated connectors were compared with those of conventional gold-plated connectors. It was found that the reliability of three-layer-plated connectors was as high as that of conventional gold-plated connectors.
Technical Paper

Development of New Manual Transmission Gear Oil for Fuel Economy

We developed a new Manual Transmission Gear Oil (MTF) named LV for improved fuel economy and CO2 reduction. MTF LV is a low viscosity fluid to reduce stir losses at lower temperatures. In general, low viscosity fluids can cause metal fatigue, wear and seizure. The MTF LV was designed to overcome these problems by maintaining the oil film thickness after it is deteriorated and improving the wear characteristics with additives. As a result, the MTF LV provides equal or better durability than the current MTF. In addition, it also has good performance at low temperatures, better shift feeling characteristics, and improved oxidation stability.
Journal Article

FAME Blended Diesel Fuel Impacts on Engine/Vehicle Systems

The impact of fatty acid methyl ester (FAME) blended diesel fuel on engine/vehicle systems was comprehensively investigated by vehicle, laboratory and engine tests. In this study, 20% FAME blended fuel (B20) was mainly used and soy bean oil methyl ester (SME) was primarily selected as the FAME. Vehicle testing with long-term fuel storage in vehicle fuel tanks was conducted, considering the most severe conditions in market use. Laboratory and engine tests were also conducted to better understand the vehicle test results. In the vehicle test, engine startability, idle roughness and fuel injection control were evaluated using nine vehicles with plastic or metal fuel tanks. All vehicles showed no problems up to 7 months. While five vehicles with plastic fuel tank did not show any problems throughout the test period up to 18 months, four vehicles with metal fuel tanks experienced malfunctions in engine start or fuel injection control following 8, 13, 13 and 18 months respectively.
Journal Article

Development of an On-Board PM Sensor for the OBD System Based on an Electrochemical Polarization

An on-board particulate matter (PM) sensor, consisting of a gas-permeable electrochemical cell with a porous yttria-stabilized zirconia solid oxide electrolyte, was developed to assist the on-board diagnostics (OBD) system of a vehicle. Exhaust is pumped from the anode side to the cathode side and PM deposited on the anode is instantly oxidized by the catalytic effects of the metal component of the electrode at temperatures higher than 350°C. The PM oxidation reaction occurs at the three-phase boundary between the anode, electrolyte and gas phase, and causes a slight change in the bulk average oxygen concentration, which produces electrochemical polarization by the difference in oxygen partial pressures between the anode and cathode. The developed PM sensor has a detection limit of 2 mg/m₃, at which level will enable PM detection in the OBD system according to the EURO VI regulation.
Journal Article

Experimental Study of the Impact of Diesel/Biodiesel Blends Oxidation on the Fuel Injection System

The stability of Diesel/Biodiesel blends can play an important role in deposits formation inside the fuel injection system (FIS). The impact of the stability of FAME/Diesel fuel blends on lacquer deposits formation and on the behavior and reliability of the FIS was investigated using blends of Rapeseed and Soybean methyl esters (RME, SME) and conventional Diesel fuel (volume fractions of RME and SME range from 0 to 20%v/v). Fuels were aged under accelerated conditions and tested on an injection test rig according to an operating cycle developed to provoke injector needle blocking. The soaking duration was found to affect injector fouling. A relationship between the injector fouling tendency and the fuel stability was established. Under current test condition, injectors fouling increased with fuel oxidation measured with Total-Acid-Number.
Journal Article

Analysis of Oxidative Deterioration of Biodiesel Fuel

Methyl esters of saturated/unsaturated higher aliphatic acids (FAMEs) and a FAME of waste cooking oil (WCOME) were heated at 120°C in an air gas flow. The samples were analyzed before and after heating, using six different methods including electrospray ionization mass spectrometry. As a result, the samples after heating were found to contain low molecular weight aliphatic compounds and oligomers of the FAME. Based on the chemical structure of these oxidation products, reaction schemes were proposed for the deterioration of FAMEs. In addition, two unsaturated FAMEs containing 2,6-di-t-butyl-p-cresol (BHT) were similarly heated and analyzed to examine the effect of BHT on the oxidation of these FAME.
Technical Paper

Next Generation High Performance ATF for Slip-Controlled Automatic Transmission

A slip-controlled lock-up clutch system Is very efficient in improving the fuel economy of automatic transmission (AT) equipped vehicles. However, a special automatic transmission fluid (ATF) which combines an anti-shudder property with high torque capacity is required for this system. In this study, we established additive technology for ATF having a sufficient anti-shudder property and high torque capacity. Based on the technology, new ATF: ATF-T4 was developed. It was confirmed in actual AT tests that ATF-T4 has excellent anti-shudder durability and high torque capacity. Furthermore, ATF-T4 has good SAE No. 2 friction characteristics, oxidation stability, compatibility with materials (elastomers, nylons, etc.) and viscosity at low temperatures.