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The main purpose of Formula SAE competition (hereafter called “FSAE”) is to let students learn the basic ability necessary for engineers through design, fabrication and test projects[1],[3],[5],[6],[7],[8],[9]. In this study the authors decided to adopt Honda CBR 600 RR which was an engine for motor cycles. Then the engine have strength enough for the light weight design[2],[4]. As the course of the competition consists of short straights and many corners for running within equal to or less than middle speed range, the engine must have excellent acceleration performance to reduce the lap times in the corners. The effective engine performance is necessary for the flat torque in all of engine speed range, especially in low engine speed range. As the regulation allows that a turbocharger is fitted to an engine, its introduction is effective for getting high torque in the low engine speed range.

This study refers to the dynamic stabilities of pitching and rolling of our manufactured Formula SAE vehicle by numerical analysis and dynamic experiments. Formula SAE Competitions are the events of design and manufacture of the Formula SAE vehicles for university students under the auspices of SAE (Society of Automotive Engineers in U.S.A.). This competition consists of static and dynamic events. The abilities for the engineering design, cost and presentation of the students are judged in the static events. The driving reliability and durability of the competition vehicle are judged in the dynamic events. For the higher winning prize at this competition, it is to get high score in not only the static events but also the dynamic events. The competition vehicle is required excellent acceleration performance, turning performance and durability in the dynamic events[1],[2],[3].

Formula SAE is one of the competitions of the manufacturing education for students, which is held by SAE. The competition consists of the static events and the dynamic events. The static events have three competitions of presentation, cost and design, and the dynamic events are acceleration, skid pad, autocross and endurance with fuel consumption. To get the higher rank in this competition, we must win the dynamic events with the high allotment points. For the purpose of the winning, we should have some advantages more than the other universities. We aimed at raising engine power and drivability. There are some ways to get engine power up such as the combustion improvement, the change of the cam profile and supercharging. We tried to install a commercial turbocharger to a normal aspirated multi-cylinder engine for Formula SAE under the SAE regulations.

The regulations of Formula SAE® competitions restrain design, tuning, and improvement on engine in order to keep safety on driving. The competitors have basically chosen a 600 cc, 4-stroke engine for motorcycle according to the regulations. Therefore, it is necessary for higher engine performance to improve combustion by investigation of air intake and exhaust component design while the regulation agreement is the most important factor. Recently, many competitors have been using a high performance Engine Control Unit (ECU) easy to suitably control the engine combustion. The competitors can focus on optimization of the intake and exhaust components using ECU. Best tuning of each component is very difficult work because the design factors of these components have complicated relations with engine performance. Here, our interest is a method to reduce the optimization time of the system.

The core education of the Faculty of Engineering at Kokushikan University is creative engineering education by manufacturing generally on the base of the result of development research. Some of the students of the Department of Mechanical Engineering and Applied Information Technology participate in the formula car program. They conceive, design, fabricate by themselves, and compete with small formula-style racing cars at the Formula SAE® (the Society of Automotive Engineers) Competition held annually in USA under the auspices of SAE. This program is planned in order to bring up the ability of settling and solving the problems through teamwork. In addition to the PBL education system, the authors refer to the result of the development research connected with this practical education in this paper.

The torsional vibration of diesel engines has become severer with the increase of exciting force by higher pressure. Therefore, the running crankshaft is highly stressed owing to the large torsional vibration. Then, torsional viscous fluid dampers of high performance have been employed in high mean effective pressure diesel engines as a measure for vibration reduction. As the dynamic characteristics of the dampers have such a great influence on the vibration of the engine crankshaft system that they cannot be ignored, the viscosity of the silicone oil and the peripheral and lateral gaps of the dampers are diversely varied in the experiment. As the equipment for the measurement of torsional vibration displacement, a phase-shaft type torsiograph equipment was adopted so as to make it easy to measure simultaneously angular displacements of the casing and the inertia ring.

The dynamic characteristics of conventional viscous-friction dampers are investigated in this paper by adopting simultaneous vibration measurement method at two points. The vibration displacements of the damper casing and the inertia ring can be simultaneously measured in this method. It has become possible that the more detailed dynamic characteristics of the viscous-friction damper can be grasped by the method. Especially, it is an effective method to grasp the behaviors of the inertia ring and the damper casing for clarifying the effect of the silicone fluid on the torsional vibration of crankshaft system. The damper casing was made of acrylic resin in order to measure the behavior of the inertia ring on engine operation. It is possible to measure the torsional vibration displacements waveforms by the optical signals from pulse tapes stuck in both peripheral sides of the damper casing and the inertia ring.

A very small electric vehicle, powered with a proton exchange membrane fuel cell operating on reformed methanol, is planned and designed in this paper to solve social problems associated with air pollution and heavy traffic conditions. Next, the driving range is simulated by the experimental data of the output and the performance. The conclusions of this paper are as follows: (1) The power train employing the fuel cell and compact brushless DC motor serves to realize high efficiency and reduce weight for energy saving.

This is the study on the vibration characteristics of the fuel-injection pump body. Recently, refinement of the fuel spray is necessary in order to reduce the toxic substance, which is included in automotive exhaust gas of diesel engine for the automobile. To jet diesel fuel in higher pressure is a method for spraying the fuel more minute into a cylinder. However, this method causes the increase in respect of engine vibration and torque nonuniformity. The fuel-injection pump body receives not only this engine vibration by the method but also impact tute by the high-pressure injection. As this result, the sufficient performance cannot be demonstrated because large vibration deformations occur at the body and the camshaft of the fuel-injection pump. The vibration characteristics of the fuel-injection pump, which can reduce these vibration deformations, are necessary in order to lead to the performance.

Three types of cylinder head gaskets which were different in their structures and materials, were adopted for experimental study to describe cylinder head motions due to thermal cycle conditions. The experimental studies were conducted by measuring (1) the temperatures on the cylinder head gasket, the cylinder head, the cylinder block and head bolts,(2) the relative displacements of the cylinder head and block, (3) the axial tensions on the cylinder head bolts, and (4) the indicator diagram, on the engine testing with a specific thermal cycle. Following conclusions were obtained as the results; The effect of the change in circulating water temperature on the sealing function of cylinder head gaskets has become clear through this experimental study. The mutual relationship between the deflection of the cylinder head and the temperature at the gasket and its peripheral region, has been able to estimate sufficiently from the results of the measurement.

The production unit number of small diesel engine cars tends to decline except recreational vehicles in Japanese market in recent years, while the production unit number in Europe market keeps on increasing owing to the merits of the durability and the fuel consumption. The small diesel engines will have to be improved in the near future by solving major problems such as noise and vibration pollution, environmental pollution, improvement in performance of diesel engines, in order to expand the production of the engines. This paper refers to a basic study on the experimental and analytical methods for the reduction of resonant vibration in each vibration mode on some cylinder blocks of small high-speed diesel engines in rated engine speed range. Hammering test method, which is easy and useful for measuring frequency response functions, is carried out in the experiments.

The cheap and compact rubber dampers of shear-type have been widely employed as the torsional vibration control of the crankshaft system of high-speed, automobile diesel engines. The conventional rubber dampers have various rubber forms owing to the thorough investigation of optimum dampers in the design stage. Their rubber forms can be generally grouped into three classes such as the disk type, the bush type and the composite type. The disk type and the bush type rubber dampers are called “the basic-pattern rubber dampers” hereafter. The composite type rubber part is supposed to consist of the disk type and the bush type parts, regarded respectively as the basic patterns of the rubber part, at large. The dynamic characteristics of the vibration isolator rubber depend generally on temperature, frequency, strain amplitude, shape and size effects, so it is difficult to estimate accurately their characteristics.

Automotive diesel engines have been developed with the aim of achieving higher performance and lighter weight. Since the torsional vibration stresses of the crankshafts have become severer with increase of specific power, torsional vibration rubber dampers of shear-type have been widely used in order to reduce the vibrations. However, the dynamic characteristics of the dampers depend on amplitude, frequency, temperature and secular change effects. Therefore, the dynamic characteristics should be separately investigated with every influence factor. This indicates that it is difficult for the damper designers to predict the dynamic characteristics of the torsional vibration dampers in engine operation. This paper refers mainly to the dynamic characteristics of shear-type torsional rubber dampers with rubber vibration isolator hardened by secular change.

The unknown characteristics of the bending vibration coupled with torsional vibration (hereafter called“coupled torsional, bending vibration”) are investigated from the experimental and analytical viewpoints. The torsional and bending vibration stresses of the crankshafts of a 6 cylinder, in - line engine and an 8 cylinder, V - type engine are measured first in order to investigate experimentally the characteristics of the coupled torsional - bending vibrations. Next, the displacements, moments and stresses of the torsional and bending vibrations of the above - mentioned crankshaft are calculated by 3 dimensional, forced vibration analysis of the crankshafting of the V 8 engine using the transfer matrix method, which has been developed by the authors. Finally, the experimental results are compared with the corresponding calculated results and the characteristics of the bending vibration stresses coupled with the large torsional vibrations are made clear.

The dynamic characteristics of the rubber dampers of compression type have been investigated in comparison with the conventional rubber dampers of shear type. The compression - type damper has been designed so as to produce compression force on the rubber part when torsional torque acts upon it. This research report proposes the design method of the new compression - type rubber dampers. The new rubber dampers have been fabricated on an experimental basis in accordance with the design method formulated by us. With the new dampers equipped in a 6 - cylinder, in - line diesel engine, the dynamic characteristics of stiffness and damping have been examined through experiments. In comparison of the experimental results between the new compression - type rubber damper and the conventional shear - type rubber damper, it has been revealed that the compression - type rubber damper has some advantageous characteristics.

It is the purpose of this paper to make clear the effect of typical torsional viscous-friction damper on the reduction of the axial, torsional and two directions of lateral vibrations from the analytical and experimental points of view. At first, a typical type of the torsional viscous-friction damper is fitted to a high-speed diesel engine and the axial, torsional and two directions of lateral vibration displacements at the pulley end are measured in order to investigate the effect of the damper on the reduction of these vibrations in the three dimensional space of the engine shaftings from the experimental point of view. Next, the characteristics of the axial, torsional and two directions of lateral vibrations of the engine shaftings are investigated by three dimensional analysis of forced vibration by the transfer matrix method, which has been developed by the authors.

This paper refers to a numerical computation for vibration displacements and stresses of a crankshaft with a shear type rubber torsional damper by the three dimensional transfer matrix method. The accuracy of this computation method is confirmed by comparing computed results with measured ones. Especially, in this work, the numerical computation method is proposed to compute the vibration displacements and stresses by means of replacing the rubber part of rubber torsional damper with a spring-dashpot model. Then dynamic characteristics are estimated by the complex torsional stiffness derived from a three-element Maxwell model. As a result the torsional vibration stress and bending vibration stress and vibration displacements (angular and lateral displacements) can be computed with an adequate accuracy. This computation method is applicable to predicting the conditions of vibration displacements and stresses, and will contribute to optimum design of the crankshaft.

Described herein is an experimental and theoretical study of the dynamic properties of torsional viscous-friction dampers for use on Diesel engines and the characteristics of torsional vibration of the engine shaftings. At first, three kinds of dampers are fitted to a 14.3 liter, V-type, 8-cylinder Diesel engine and the torsional vibration displacements at the pulley are measured in order to investigate the characteristics of torsional vibration of the shaftings with the damper. The kinematic viscosity of silicone oil is diversely varied in this experiment. It is confirmed that an optimum viscosity exists for each damper from an experimental viewpoint. Next, the dynamic properties of the dampers and the characteristics of torsional vibrations of the engine shaftings are investigated by 3 dimensional analysis of forced vibration by the transfer matrix method, which has been developed by the authors.

A numerical simulation method by transfer matrix method is proposed to compute the vibration stress waveforms of a V-type, 8 cylinder diesel engine crankshaft in this work. This method will be able to predict the conditions of vibration stresses and be useful to design a crankshaft. The accuracy of this numerical method is confirmed by comparing the simulation results of the computation with the measured data. As a result of the comparisons with the measured data, it has been assured that the vibration stress waveforms can be computed with adequate accuracy by considering from 0.5-th to either 10-th or 12-th order per 0.5-th order harmonic components of exciting forces for a 4-cycle engine.

This paper refers to a numerical calculation method, in which the transition matrix method is employed. The method estimates torsional vibration amplitude of a crankshaft with a rubber damper by taking the dynamic characteristics of the rubber part into consideration. Firstly, the rubber part is replaced with a three-elemental Maxwell model, which is determined by the results of static tests, such as stress relaxation test, creep test and static torsional test. The basic data used for the determination of the element values on the Maxwell model are obtained by these tests. Secondly, the vibration system of a crankshaft with a rubber damper is replaced with a linear lumped model, in which the torsional stiffness and damping coefficient of the damper rubber part are decided by using the element values of the Maxwell model.