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To examine factors influencing side impact compatibility, as a first step, car-to-car tests were conducted to investigate the effect of sill interaction. As a result, it was found that sill interaction had a less significant effect on side impact performance than reducing the load aligned with the dummy. In addition, a series of Mobile Deformable Barrier (MDB) tests were performed to corroborate the conclusions of the car-to-car tests. Comparison of the results of these MDB tests showed that the effect of reducing loading aligned with the driver dummy is more significant than that of engagement with the target car's sill, which is consistent with the car-to-car test results.

This paper investigates test procedures for vehicle frontal crash compatibility. Both Full Width Deformable Barrier (FWDB) tests and Moving Deformable Barrier (MDB) tests were studied to assess relevant factors of compatibility issues. The FWDB test with load cells was examined to evaluate the stiffness and interaction areas of vehicles (sometimes referred to as the “aggressivity” of vehicles). Compatibility metrics were computed using barrier load cell data and the output from the FWDB test was compared with that from the Full Width Rigid Barrier (FWRB) test. Since the results obtained from these two full width tests were considerably different, a full frontal vehicle-to-vehicle test was carried out to identify structural deformation modes. The results indicated that similar deformation modes were observed between the vehicle-to-vehicle test and the FWDB test.

New diesel particulate filter (DPF) by using nonwoven fabric made of silicon carbide (SiC) ceramic fiber and formed cylindrical shape with bellows folds has been developed. It has very high durability and excellent filtration performance. It has the unique filter structure that nonwoven cloth made of SiC fiber is held between two metal wire cloths in order to make the filter clogged by Particulate Matter (PM) regenerate. Urban buses equipped with this new DPF already run about 40,000km around Tokyo metropolitan and Kawasaki City area.

Recently further improvements of fuel economy and performance of truck diesel engines are required in the market. At the same time, countermeasures for exhaust emissions are requested as a clean air activity. So the improvement of performance and the reduction of emission are keysubjects today. As a countermeasure for both problems, the reduction of friction is effective. The authors took notice of the pumping loss, and analyzed the pumping loss at the gas exchange process and improved the performance by a multi valve intake & exhaust system. Particularly the multi valve system is effective on a higher boost and/or smaller sized engine because of its larger air and gas flow through the relatively small passage. And the reduction of the fuel rate resulted in better reliability with regard to thermal load and exhaust temperature.

The spark-assisted methanol engine has disadvantages like poor fuel economy especially at light load and low spark plug durability affected by combustion characteristics. Investigations of combustion characteristics of the spark ignition system and the autoignition system in the methanol engine and discharge characteristics of a spark plug are described in this paper. It is clear that effective autoignition was accomplished by increasing the compression ratio and adopting an EGR system in the spark-assisted methanol engine. This new improved methanol engine which is named HAMS achieved good fuel economy at light load, a low NOx emission and longer spark plug life. And a heat insulated piston with a stainless steel cap is being investigated for further improvement of autoignition combustion characteristics.

Gaseous emission measurements of a diesel engine including hydrocarbons (HC), carbon monoxide (CO), and oxide of nitrogen (NOx) are made in accordance with the procedures specified in the Federal Register. However, it is very difficult to maintain constantly the accuracy of these emission measurements due to failure of the emission analyzer. The authors have thus developed the Pre-Alarm Diagnostic System for a Diesel Emission Analyzer. Firstly, the authors have carried out analysis of all failure modes that are classified into initial failure, random failure and wearing-out failure, plus tolerance level for prediction of failures and method of predicting failures. Next, the authors have developed the Pre-Alarm Diagnostic System that is able to easily discover these failures before the exhaust emission test. In this system, 40 sensors, such as pressure, temperature, voltage etc, are laid in each pipe line of connection between exhaust emission sampling pump and analyzer.

For the 1990's diesel engines, particulate control has been an important problem. The purpose of this paper is to discuss emission control needs for heavy duty diesel truck engines for the 1990's. This paper will focus on the factors such as fuel injection pressure and fuel properties which most affect particulate emission. The characteristics of diesel spray in the atmosphere and also actual combustion of a turbocharged and charge-cooled H.D. D.I diesel engine were studied as a function of injection pressure ranging from 50 to 150 MPa. Experimental results show that high pressure injection improves the atomization and air entrainment. Though Bosch smoke level, fuel consumption and combustion period decreased with the rise of injection pressure, particulate emission in EPA transient test cycle did not decrease dut to an increase of SOF.

Considerable amount of research work on hydrogen fueled engines has been conducted for 17 years in Musashi Institute of Technology. The primary purpose of the research has been to develop a hydrogen powered autmobile, and in order to realized it, various innovations have been applied and tested. The newest outcome of this 17 years research was Musashi-7 Track, which demonstrated its performance in Innovation vehicle Design Competition held in Vancouver in July 1986. Musashi-7 Track was a modified medium duty truck, which was originally made by Hino Motors, and had a hydrogen powered engine. The track was equipped with 150 ℓ liquid hydrogen (LH2) tank and 8 MPa high pressure LH2 pump. The pump delivered 8 MPa high pressure hydrogen gas to the engine and the fuel was injected to a hot surface igniter in DI combustion chamber. This type of hydrogen enigne has following advantages. Firstly, fuel corrier weight and volume can be much smaller than those of metal-hydrides (MH).

In order to reduce particulate and NOx emission from the direct injection diesel engine, most researchers have been expecting the utilization of higher injection pressure and injection rate for improvement of diesel combustion. In the case of pump-line-nozzle system, the injection pipe line is very important with regard to the high injection pressure. Namely, the pipe line must be able to resist not only high pressure but also cavitation erosion. In this paper, the effect of high injection pressure, injection rate and sharp cutting at the end of fuel injection are discussed along with cavitation phenomena on the injection pipe line. And durability tests on the pipe line system under high injection pressure using a test rig are also described. Regarding durability tests, several measures have been taken for the injection pipe. As a result, the authors have found that the best solution for the injection pipe is a composite pipe made with SUS and steel.

The results of a systematic study on sources of particulate from direct injection diesel engine are presented. Particulates, divided between dry soot and soluble organic fraction were measured under a variety of steady state operating conditions from a D.I. diesel Engine. It was found that SOF (soluble organic fraction) was produced under light engine operation and dry soot was a function of engine load (increased with fuel flow rate). The soot formation and oxidation processes were studied by two methods: Direct photography and laser shadow-graphy.

A hydrogen powered vehicle system consisted of LH2 tank high pressure LH2 -pump, a device to inject hydrogen onto the hot surface, and ignitor in turbo-engine of CR 12:1 had been developed by Musashi Institute of Technology- Recently the authors applied this system to a medium duty truck produced by Hino Motors Ltd. Then following improvement were required. (1) Gas tightness and endurance of hydrogen injector were improved by the selection of material, size, finishing and by suppling a small amount of lubricating oil. (2) Mixture formation of the injected hydrogen with the compressed air was improved by tuning up the size and number of the nozzle holes and injection timing with the hydraulic pump and valve. (3) A small amount of hydrogen was supplied into the intake manifold. It reduced the combustion noise and also it recovered the evaporation loss in the LH2 -tank.