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Viewing 211 to 240 of 36595
1990-02-01
Technical Paper
900210
A. van Zanten, R. Erhardt, A. Lutz
The design of ABS- or vehicle control systems by means of computer simulation needs adequate tire models. Recordings of the wheel speed during ABS control show oscillations caused by the rapid pressure changes in the wheel brake cylinder. Investigations in lateral tire dynamics show a phase shift between the slip angle and the lateral tire force. These transients can not be explained by simulation if the usual stationary tire input-output behaviour is supposed. Thus the investigation of the oscillations requires a different approach to the modelling of the tire. In a first step measurements with an experimental car equipped with a computer for data acquisition and control and with various sensors - e.g. a Rotating Wheel Dynamometer - were carried out. The measurement results showed a correlation between the oscillations in the wheel speed and the braking force caused by the pressure pulses as well as high frequency oscillations in the lateral tire forces.
1990-02-01
Technical Paper
900264
William J. Fleming
Intense worldwide activity is currently focused on development of magnetostrictive torque sensors. The sensors are both non-contact and provide high sensitivity in combination with robustness. They are therefore prime candidates for use in torque-feedback closed-loop controls of automotive engines and transmissions. Previously, both linear and nonlinear analyses of the branch-design of magnetostrictive torque sensors were given. This paper goes beyond prior work to include cross-design and solenoidal-design sensors (designs that are more commonly used). For each sensor design: general models are derived, equivalent electrical and magnetic circuits are developed, and equations governing signal outputs are given. A comparison is done of magnetic circuit operating behavior for sensors designed to fit into the same space on a shaft made of maraging steel.
1990-02-01
Technical Paper
900260
Ronald S. Patrick, J. David Powell
A technique to estimate the in-cylinder air-fuel ratio (AFR) of a spark-ignition engine has been developed. This method uses cylinder pressure and temperature measurements taken during a single engine cycle to calculate the ratio of molecular weights before and after combustion (G-ratio). The G-ratio is uniquely related to the AFR of the cylinder charge. This method is suitable for use in closed-loop AFR control strategies. A G-ratio based AFR estimator was constructed using experimental measurements of cylinder pressure and intake and exhaust manifold gas temperatures. Its AFR estimation accuracy over the engine's steady-state operating range was 4.85% RMS based on a ten cycle average. The accuracy will improve substantially if in-cylinder temperature measurements can be made.
1990-02-01
Technical Paper
900256
Ken Naitoh, Hiroyuki Fujii, Tomonori Urushihara, Yasuo Takagi, Kunio Kuwahara
Computation of the three-dimensional flow in the intake ports and the cylinders of real engines, including moving valves and piston, has been carried out by solving the Navier-Stokes equations. No explicit turbulence models are used. An extended version of the SIMPLE and ICE method is employed to simulate density variations in engines, which are connected with compression rate, heat transfer, and compressibility. A third-order upwind scheme is combined with this method. Computational results show complex flow fields such as separated flows near the valve seat and small vortices of the order of the mesh size near the end of compression. These computational results are compared with the LDV measurements.
1990-02-01
Technical Paper
900254
M. Zellat, Th. Rolland, F. Poplow
: The three dimensional computer code KIVA is applied to calculate combustion in an IDI Diesel engine. The ignition delay is described by a four step kinetics model involving a generalized radical. The high temperature combustion phase is computed using a model due to Magnussen. The model of soot formation is due to Tesner. Finally, an extension of Magnussen' s combustion model allows one to describe soot formation in a turbulent environment. In the present computations, a classical k-ε turbulence model and the associated laws of the wall are incorporated. Comparisons between computational and experimental results are emphasized. The results under four engine operating conditions are found to be encouraging and give hope for the code being predictive soon. However, such aspects as e.g validation of the heat tansfer calculation at the walls and nitric oxide formation have not been taken into account thus far.
1989-09-01
Technical Paper
891772
G. E. Roe, T. E. Thorpe
Motorcycles are prone to two basic steering instabilities, a low-speed high-frequency flapping of the handlebars (‘wobble’ or ‘flutter’) and a high-speed low-frequency snaking of the whole machine (‘weave’), both potentially dangerous. This investigation replaced the standard production frame of a large capacity machine with two new frames of ‘duplex’ tubular type. One supported the engine mass from below - a so-called ‘cradle’ frame - and the other from above. The stiffness characteristics of both experimental frames were calculated and optimised by Finite Element techniques. The resulting stability of the motorcycle was dramatically improved in each case, with the cradle frame showing superior flutter stability. Both frames also had excellent handling qualities. The frames were tested under a wide range of parameter variation and loading conditions. The loss of flutter stability on fitting a currently-fashionable smaller front wheel was viewed with some concern.
1989-09-01
Technical Paper
891773
John W. Zellner, Brian K. Kebschull, Tetsuo Tsuchida
A theoretical and experimental investigation of the effects of antilock braking (ALB) on motorcycle braking in a turn (BIT) is described. The analyses involved computer simulation of the dynamic interaction among rider, motorcycle, ALB, and roadway during BIT maneuvers; and instrumented full scale BIT tests with expert and novice riders. The analyses and full scale tests used an example all mechanical, independent front and rear ALB system. The results showed that ALB can help maintain motorcycle stability in straightline and gradual turns at high and excessive brake force levels. In more severe turns, the motorcycle can capsize at low brake force levels, below those which are typically needed to trigger ALB operation. As a consequence, from a fundamental standpoint, contemporary conventional ALB systems cannot be considered to influence or improve motorcycle stability during limit braking in moderate or near limit turns.
1989-09-01
Technical Paper
891775
Mitsuo Itoh, Gakurou Matsuda, Yoshinori Takano, Takafumi Michishita
The CAD/CAM system, named “SCADEM-2”, in Suzuki Motor Co., Ltd. Motorcycle Engineering Division was developed, based on the old system “SCADEM”. 3D CAD/CAM system “SCADEM-2” is more accessible for operating, more speedy for processing and more complete for generating figures than the old system. Since this system opened in 1987, has been popularly used by most designers of Motorcycle Engineering Division. It's main functions are Design (3D), Drafting (2D), Electrical Schematic, and FEM Processing.
1989-09-01
Technical Paper
891774
Shouichi Yoshimura, Shunji Asano, Toshitaka Kouga
In product development of motorcycles, application of CAN at the initial design stage is more necessary than ever to ensure the reliability of the product and also to shorten the lead time of product development. Finite element method (FEM) plays a crucial role in this respect. In the application of FEM to the development of small vehicles, such as motorcycles, analysis must he carried out in a short period and at a low cost. However, FEM requires complex operations and therefore, designers have been unable to use this method satisfactorily. In order to improve these matters, we have developed a system, called STAGE-FEM, which enable the engineers to make FEM models of components of motorcycle and to evaluate the analysis results easily.
1989-09-01
Technical Paper
891778
Ma Jie, Gu Hong-Zhong, Yin Zi-Jia
For the sake of avoiding real engine's test during designing of resonant system, a programme for optimization of resonant system's sizes has been compiled. To meet the resonant system's demands of operating in transient process another programme was set up which could simulate the instantaneous process of diesel engine with resonant inlet system, so that the instantaneous response of resonant systems in different size could be compared.
1989-09-01
Technical Paper
891776
Toshio Tsuta, Shozo Suehiro
CAET - I, which stands for Computer Aided Engineering System of Tansha (motorcycle), an efficient design system for frame structure in motorcycle has been developed, incorporating available computer systems for structural analysis and drawing system. As the first step, general methods of dynamic load estimations in motorcycle riding were studied, and computer simulation programs were developed. As the next step, a program was developed to enable the operator to proceed with analysis and design in the conversational mode. Related programs are also available to evaluate fatigue life of stress-concentrated parts such as pipe junctions, gusset corners, etc. All these programs are integrated in the CAET- I system, which easily produces precise initial design in a very short time.
1989-09-01
Technical Paper
891784
Fumikazu Kimura, Tetsuya Kokudai
Motorcycles arrange the radiator in front of the engine. So, the size of radiator is not wider than the width of engine or the width of frame. We design the motorcycle similar to road-racer. We hope that the width of radiator is as narrow as possible, because motorcycle can run as fast as possible. So, it is necessary that the width of engine and frame is narrow as much as we can, and the width of radiator is limited. But for the water-cooled engine, the temperature of coolant has better be low so as to product the effective combustion. So, it is necessary that the width of radiator has better be wide, but it contradict the above. “U-Shaped Radiator” solves the above problem. The structure is that radiator bends U-form in the front of motorcycle. Now we can improve the cooling performance (+30%) in comparison with the same width radiator.
1989-09-01
Technical Paper
891789
Jerry E. Kashmerick
The emergence of numerous new products plus higher product and quality standards on existing products, has focused increased attention on effective gasketed joint sealing. Asbestos free materials added additional difficulties in achieving functional and cost effect solutions. Careful attention in product design and product manufacturing concerning gasket requirements, can reduce overall product testing and evaluation times and costs. Static testing on product hardware can be used to evaluate the distribution of sealing loads at installation, and over time. Dynamic testing is required for final verification of gasket joints. These can include a variety of tests ranging fro m customer endurance and durability tests to special tests more unique to the gasket industry for accelerating gasket testing and evaluation. The purpose of this paper is to provide information with regard to selecting and evaluating gaskets for small engines.
1989-09-01
Technical Paper
891786
Atsuo Ohta, Tetsuo Yamagata
In this paper, the results of analysis of reverse traveling of mortorcycle are described together with the characteristics of its structure and of the control system of reverse system mounted on a mas-production model of mortorcycle. Traveling of simulation and traveling experiments have been performed to comprehend the kinetic characteristics in reverse traveling of mortorcycle in developing reverse system for mortorcycle, and setting of an appropriate range of reverse traveling speed was made. Then in order that the vehicle speed be controled within the range of such set speed, and electric mortor has been chosen as the power source for its easy access in controlling, and it has been so decided that the mortor is controlled by a micro-computer. The control also includes switching control of mortor current, logical control that restricts reverse traveling and failsafe control.
1989-09-01
Technical Paper
891754
Hidetaka Kobayashi, Hideyuki Azegami, Akiyoshi Okitsu
The objectives of the present paper are to propose a variance evaluation method for modal parameters identified by the least, squares method with an experimental transfer-function, and to show that the evaluated variance can be used to optimize the accuracy of the parameters by selection of proper excitation type, weighting function and so on. The variance of the modal parameters was evaluated by a first order approximation and the discrete values of the experimental transfer functions as were modeled as stochastic variables. Also, the variance of the transfer function was evaluated using the coherence function based on a theory of statistical error. Application of this method to a simple beam made of acrylic resin showed that the variances can be used to optimize the accuracy of the modal parameters. Furthermore, results for the cowling of an outboard motor show that the proposed method is applicable to actual structures.
1989-09-01
Technical Paper
891757
Hiroaki Otani, Masaki Okazaki
In the case of small outboard motors, intake noise is the main sound source. Consequently, intake silencer improvement is a significant factor in the development of outboard motors. A theoretical simulation was developed to aid the design of improved silencers. This simulation was based on the one-dimensional transfer matrix method (2,3)* and was validated by measurements recorded from a 2-channel FFT experimental testing apparatus. The resonance and anti-resonance characteristics of the measured and calculated results showed good consistency. The simulation technique was utilized to develop an improved configuration and evaluation on a running engine indicated a significant noise reduction. This study has demonstrated that the simulation technique is an effective silencer development method.
1989-09-01
Technical Paper
891759
Sarim N. J. Al-Zubaidy
The detailed shape of any centrifugal impeller channels may be determined by using either of two general approaches, namely the direct and the indirect design approach. A radial flow centrifugal impeller that satisfies specified duties has been designed for a prescribed space rate of deceleration using the direct approach- The same duty has also been met by an impeller designed using the indirect approach (both impellers have the same principal dimensions). For the sake of comparison, provision has been made regarding the impeller that was designed using the indirect procedure to ensure a resulting rate of deceleration similar to the prescribed schedule for the direct approach. This was achieved by systematic adjustments of the detailed geometry of the impeller. It does seem that the direct approach is less time consuming and less expensive in terms of computational costs than the indirect approach.
1989-09-01
Technical Paper
891760
Junichi Kagawa, Hiroshi Kato
The latest engine development trends have blended the consumers demands for high performance and horsepower output with Governmental regulations for fuel efficiency and emission reductions. As a result of this, it has become increasingly common to use a four valve per cylinder design. One application in particular is a four-stroke cycle engine for motorcycles. In order to incorporate all of these elements into one design, space constraints being considered, spark plugs of a reduced size were developed. To this end, compact spark plugs attain the following advantages over the conventionally sized plugs: 1) Improved volumetric efficiency due to an increase in valve diameters and a reduction in valve arrangement angles. 2) Improved rigidity of the material in the area between the threaded plug hole and the valve seat.
1989-09-01
Technical Paper
891765
Manabu Furubayashi, Yoshihiro Tadaki, Masaharu Uchida
This report describes the process and the result of captioned development. At first, the process of understanding the end user's requirement for farm tractors are described, then the technical factors for fulfilling the requirement are described. By these process we have achieved to satisfy the OEM requirement in many aspects especially the highest torque and horsepower among 1.5L class diesel engines.
1989-09-01
Technical Paper
891764
Ernst Hatz
MOTORENFABRIK HATZ in West Germany has been manufacturing air-cooled and water-cooled diesel engines for the last 78 years. Our single-cylinder, 70 Series, has met with worldwide success. Our new single-cylinder line. SUPRA, builds on that success and introduces several unique features including a new mass balancing system, both clockwise and counterclockwise rotation, and encapsulation for noise reduction. This paper describes the overall design features of the SUPRA including the unencapsulated as well as the encapsulated design.
1989-09-01
Technical Paper
891766
Hirotaka Nakajima, Tadao Okazaki, Masaaki Michizoe, Akira Hayatani
Abstract With a drastic advance of computing software and hardware, recently, simulation techniques play snore important role in development and design of diesel engines. Especially, Finite Element Method (FEM) is indispensable for design of diesel engine components, as a tool of optimizing each part and selecting the Materials. Meanwhile, it is one of the greatest theme for all engine designers to raise compactability and high-performance of small engines. At the same time, we have to respond to social needs, that is safety, reliability, durability, and comfortability, for reduction of noise and vibration. Moreover, for design of engine components, we always try to reduce a period of development and make more economical components because we have to consider those cost. To meet this severe requirement, it is needed not to apply the simulation techniques just as they are, but to establish the higher and more useful ones.
1989-09-01
Technical Paper
891767
Jack M. O'Leary, George W. Gatecliff
A computer program capable of predicting cyclic engine bearing forces, and dynamic unbalance in a single cylinder engine is used to evaluate and optimize counterweight size and angular location. The program requires inertial, geometric and locational input for each of the moving parts in the slider-crank mechanism. This information together with a cylinder pressure history allows calculation of dynamic bearing forces. The vector addition of these bearing forces with cylinder pressure force and cylinder side wall force determines the net unbalanced force produced by a single cylinder engine. The program evaluates means of reducing unbalance forces by simulating the addition of eccentric masses attached to the crankshaft and/or other shafts rotating at the same speed. Rotating mass can be added at any location along the crankshaft or any other parallel shaft rotating in the same (forward) or opposite (counter) direction.
1989-09-01
Technical Paper
891770
Kouichirou Kurata, Masahiro Nishikawa, Jumpei Abe
A structural analysis for the connecting rod was performed in consideration of bearing crush, oil clearance and initial deformation of the big end bore caused by tightening force of the rod bolts. This analysis enabled to calculate not only the bearing pressure distribution but also the three-dimensional stress state with accuracy. A new fatigue criterion for multi-axial out-of-phase stress was proposed by using mean stress tensor and alternating stress tensor of complex number in this study. This criterion was developed to improve the classical multi-axial “yield criteria”. This criterion is simple, comprehensive and suitable for the evaluation of three-dimensional FEM results. The connecting rods exhibiting high reliability under severe conditions were investigated through the stress analysis and the new evaluation criterion.
1989-09-01
Technical Paper
891750
Vinay Harne, S. R. Marathe
In Two Stroke Spark Ignition engines the thermal efficiency increases with increase in compression ratio. Also, with higher compression ratios the Ican burning limit increases because of the reduction in initial combustion period. Under part throttle conditions the fuel economy can be improved with higher compression ratios. However, this is often associated with problems of knocking and roughness. The paper describes a new type of cylinder head design which allows operating at high compression ratios under part load conditions and at lower compression ratios under full throttle condition. This paper begins by discussing the necessity for developing an automatic variable compression ratio engine (AVCR engine) and continues with the explanation of working of an experimental engine developed by TVS Suzuki Ltd. The mathematical model for theoretical prediction of the pressure crank angle diagram is then explained.
1989-09-01
Technical Paper
891865
T. A. Carlson, A. L. Humke, W. A. Schmitt, M. R. Vandendriessche
The Deere 4.5 liter turbocharged diesel engine is the first engine model in the 300 Series family to be updated with an evolutionary series of design improvements. Features include a new cylinder head for improved engine breathing, as well as significant improvements previously introduced on selected models in the current 300 Series engine family. This paper will highlight some of the component design changes that have resulted in improved performance, reduced heat rejection, improved gasketed joint integrity, and component standardization that provides increased engine value to the customer.
1989-09-01
Technical Paper
891860
Arthur Akers, Su-Chen Jonathon Lin
This paper presents a mathematical model of an axial piston pump/two-stage electrohydraulic controller combination. The controller uses swashplate position feedback and has been specially designed so that it is of low-to-moderate cost and so that it can respond quickly to control changes. The first stage of the controller makes use of a squeeze film damper and is dynamically stable. The model may be used for design purposes inasmuch as geometry and operating conditions can be varied over wide limits and the resulting dynamical behavior evaluated. Calculation of the dynamic response to a control current for the operating conditions and geometry of the valve shows close agreement with experiment.
1989-09-01
Technical Paper
891861
K. A. Edge, K. R. A. Figueredo
An experimental investigation into model reference adaptive control of an electro-hydraulic servo-mechanism is reported. The servo-system consisted of a zero-lapped servo-valve and asymmetric actuator positioning a load of 890 kg. Parallel model reference adaptive control was employed with the desired level of system performance being specified in terms of a reference model transfer function. The performance of the basic scheme is enhanced by the introduction of a novel integral-action controller and typical performance characteristics with and without the controller are presented. The ability of the adaptive controller to maintain a consistent level of performance when subjected to a pseudo-random control signal is also discussed.
1989-09-01
Technical Paper
891862
P. Gill, P. R. Ukrainetz, R. T. Burton
The rapid advances in computer technology over the past decade have provided the Fluid Power industry with a means of integrating modern control concepts with high performance hydraulic devices such as servo valves. One such concept, pulse width modulation (PWM), has been around for several decades, but it has been only recently that the full potential of the technique has been realized from an application's point of view. This paper shall consider the use of pulse width modulation techniques as a means of driving a two-stage flapper type servovalve and load. This work presents both analytical and experimental open loop responses of the valve and load under conditions in which variations from an operating point are substantial. The effects of signal filtration of the modulated input are traced through the valve and load by placing the modulation signal at various locations in the valve.
1989-09-01
Technical Paper
891848
John Rothwell
Flexible automation can succeed only when design and manufacturing join forces in the fight for competitive advantage. Our world-class products need the advantages of superior quality, lower production costs, improved market introduction and on time customer delivery. The integration of product and process design is essential in order to remain a survivor in todays highly competitive world markets. Utilizing the latest in manufacturing weapons such as CAD/CAM, MCAE and CIM can be the key to success in the war for global competitive advantage.
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