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This paper describes the Nippondenso in-line pump system designed for U.S. 1991 emissions regulation for medium duty diesel engines. With the combined use of the further improved in-line pump, NB-S and the multi-hole nozzle with a smaller orifice diameter, the required injection pressure of 100 MPa to 120 MPa at the nozzle can be achieved. However, some problems to be resolved exist in the subject fuel injection system: (1) secondary injection, (2) cavitation erosion of injection pipe, (3) higher pressure sealing of fuel, (4) undesirable fuel delivery curve vs. pump speed (called “Trumpet Shape” fuel delivery curve) Thus technical measures to cope with those problems are explained in details.

The purpose of this paper is to discuss injection rate control of the nozzle for direct injection engines. This paper will focus on fuel flow analysis of the nozzle, a key component of Fuel Injection Systems (FIS). The optimum designed nozzle improves fuel flow efficiency and controls injection rate. To meet emission regulations in 1990's, FIS are required to produce higher injection pressure and injection rate control which creates better fuel spray atomization and higher utilization of air. But the higher injection pressure makes injection rate control difficult. In particular, injection rate control by needle lift traveling control is difficult because fuel flow characteristics in the nozzle change with injection pressure and needle lift. Furthermore, the forced control of needle lift results in poor fuel spray atomization.

To meet the 1990s' requirements for diesel engines, the realization of innovative fuel injection system has been expected. Thus the fuel injection system named ECD-U2 was newly developed. ECD-U2 is the electronic unit injector system with high pressure common rail of which features are explained as follows; Fully electronic and flexible control in fuel quantity and injection timing. Adjustable injection rate shape Optimum injection pressure control Superior packageability and low drive torque loss. In this paper, design strategies, actual hardware configurations and some test results of ECD-U2 are described.

As a part of a project to develop high performance, compact and lightweight vehicle radiators, a highly corrosion resistive fin has been developed, especially for use in the salt-laden environment. It is a thin plate with a mutual diffusion layer of Cu-Zn formed on either surface. Owing to this composite structure, not only the corrosion resistance is double that of Cu-Sn alloy fins that are currently in use with a thickness over 20% smaller than the latter (38 μm vs 50 μm), but the corrosion of the bonding solder has been reduced to one half because the Cu-Zn diffused layer has brought about substantial reduction in the fin's surface potential.

The purpose of this paper is to discuss spray control of nozzle for heavy duty diesel engines. This paper will focus on fuel flow analysis of nozzle, key component of FIE (Fuel Injection Equipment). The optimum designed nozzle controls fuel flow and improves flow efficiency. FIE is required to produce higher injection pressure which creates better atomization and higher utilization of air. But the higher injection pressure results in increased pump driving torque, larger pump size and higher cost. To improve the fuel flow characteristic of nozzle, we analyzed it and developed a theoretical analysis method with computer model simulation to the optimum design nozzle. We also confirmed its effect by experiments.

This paper reports on research conducted at Nippondenso Co., Ltd. and Meiji University on nozzles for heavy duty diesel engines. It focuses on fuel flow analysis in the nozzle, a key component of Fuel Injection Systems (FIS). The optimum design nozzle improves fuel flow and spray characteristics. A newer and tougher emission regulation from the EPA for heavy duty diesel engines will be inevitable from 1998 onward. The goal of every company is to design new FIS in advance which meet the regulations of the future rather than paying for expensive developing costs after new laws have come into effect. To meet the regulation, requirements for FIS are higher injection pressure and injection rate control which create better fuel spray atomization and higher utilization of air. In particular, the nozzle must ensure that high injection pressure is effectively converted to fuel spray without pressure losses.

The smaller and lighter SV-06 sliding vane type compressor has been developed as the successor of the swash plate type 10P08 compressor for mini-car air conditioning applications. The SV-06 is the first vane type compressor in the world which utilizes an aluminum cylinder and rotor to achieve weight reduction. This was accomplished by introducing several new features to the design, such as a boron treated vane and smooth cylinder profile. Thinner vanes and a high performance oil separator were also introduced for compactness. This paper presents the many design features that allow small size and low weight while maintaining compressor performance and reliability, and focuses on the most important technology: (1) Abrasion Characteristics of Boron Treated Vane Against Al-Si Alloy (2) Oil Separator Performance

A highly corrosion resistant drawn cup type evaporator was developed. During the development of this evaporator, the corrosion characteristics of evaporators in the field were examined in detail. Profound understanding of the corrosion mechanism led to the development of a new, unique, corrosion test method which simulates the actual evaporator field service environment. The main factors involved in increasing the corrosion resistance of the brazing sheet are (1) reduction of iron and silicon content in the core alloy and, (2) addition of titanium to the core alloy. In the present alloy, titanium content varies lamellarly through the thickness of the core alloy. Regions of high titanium content have a more cathodic potential, thus causing corrosion to proceed along the low titanium content lamellae. Consequently, the reduced iron and silicon contents, and the titanium addition, have the net effect of reducing the pitting corrosion rate.

Extensive work was conducted to develop a corrosion resistant brazing sheet alloy and to apply it to a drawn cup type evaporator in automotive air conditioning system. The items to be investigated included the influence of chemical composition of the core alloy on corrosion resistance, suppression of erosion during the brazing cycle, and enhancement of the brazing sheet formability. Additional investigation was conducted to develop a new corrosion test method on the basis of better understanding of the mechanism of corrosion in the field and to evaluate the corrosion resistance of a evaporator fabricated from the new alloy. This paper, as Part 1, describes the results of alloy development from the metallurgical and electrochemical point of view.

The purpose of this study is to make clear the relationship between flow characteristics in the nozzle and injected spray characteristics. In this paper, we discuss the effect of the sac volume in the standard hole type nozzle on fuel flow and spray. The main object of this paper is to analyze fuel flow characteristics in the nozzle by using the enlarged model nozzles. Spray investigations confirmed that reducing the sac volume causes changes in the fuel injection direction at the initial stage of injection and in the spray penetration over consecutive injection. Flow investigations in the injection hole clarified that meandering the flow in the hole causes changes in the fuel injection direction. Flow investigations in the sac chamber clarified that separating the flow from the sac wall causes meandering the flow in the hole. Furthermore, the methods to restrain the flow in the sac chamber from separating from the sac wall were discussed.

In recent years, diesel engine exhaust gas regulations become more severe due to environmental concerns. Especially, particulate reduction is one of the biggest concern, and the reduction through high injection pressure has been studied.(1), (2) and (3) However, much is not yet known about the influence of changes in fuel flow inside the nozzle tip on atomization and engine performance, and there would exist a lot of room for exhaust gas reduction through the nozzle modification. In this research we found that changing the shape of the nozzle tip showed a remarkable difference in the smoke emission at low engine speed, analysis showed that difference in the flow rate at the nozzle orifice cause difference in the fuel spray droplet size and therefore the difference in the smoke emission.

The electricity stored in the battery is the only source of energy driving an electric vehicle (EV). Therefore, the target of the air conditioning system for EVs is to cool and heat the air in the cabin and demist the wind shield using a small power consumption. We have developed a dehumidifying heat pump system that consists of an interior unit constructed to separate the recirculation air flow and fresh air flow, an exterior unit capable of controlling the absorption and radiation of heat, and an inverter-controlled, electric-driven compressor. The results of an experiment using this system proved that it could provide comfortable cabin air and good visibility through the wind shield with small power consumption at ambient temperatures ranging from -10°C to 40°C.

Considerations have been made on using turbine pumps as in-tank fuel pumps for electronic fuel injection systems (EFI). Flow channel dimension values, which had not been previously used for these types of pumps, were found to be very suitable for use as a fuel pump. The oil film visualization method was used to observe the flow pattern within the pump, and the results served to improve the flow channel shape. This contributed to designing a compact and efficient high-pressure fuel pump.

During motor vehicle operation, the image processing and pattern recognition of various external visual information to assist human vision is an effective method to improve safety and driving comfort. Research into image processing and pattern recognition, supported by advancing device and computer technology, is entering the age of practical application. Against this background, we have developed a system to visually detect, recognize and transmit to the vehicle operator road signs, which are definable patterns, as the first step in the application of image processing and pattern recognition technology to the automotive sector. The major points of this system are as follow: 1. A color processing system was adopted which reduces the effects of brightness and shadow, and implemented in dedicated hardware. 2. The development of dedicated hardware for template matching enables the real-time extraction and processing of defined patterns within the image.