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Viewing 70801 to 70830 of 110604
1991-11-01
Technical Paper
911311
A.M. Ibrahim, Y.M. Abdel-Rahim, I.G. Ibrahim
A comprehensive investigation of the chemical equilibrium thermodynamic properties (M, CP, h and s) of the products of combustion of ethanol-octane and methanol-octane blends in air is presented. Complete spectrums of fuel blends (ranging from pure octane C8H18 to pure ethanol C2H5 OH or methanol CH3OH), fuel-air mixtures (from very lean, ϕ = 0.15 to very rich, ϕ = 2.0) and combustion products temperature, T and pressure, P (in the ranges of 600-5000 K and .5-1000 ata) are examined. Mole fractions of the most important 16 product species are calculated and discussed. The extent of disscoiation and energy loss terms are defined, evaluated and discussed. The real gas effect on these properties in the low temperature range (600 - 2400 K) when evaluated by correlated equations of Ref. (1)* are found to be insignificant.
1991-11-01
Technical Paper
911312
Hans Holzleltner
Two-stroke racing engines are nowadays in a very high developed stage and are used specially in racing disciplines, where extremly high power to weight ratios are required. But the type of racing sometimes leads to a completely different demand in performance and power band. Two of this contrary applications are Kart and snowmobile racing. This investigation shows, why the demand is so different and what measures on the engines have to be taken, to accomplish this requirements.
1991-11-01
Technical Paper
911290
Katsuhiko Matsuo, Nobuyuki Tani
HST(Hydrostatic Transmission) of BANTAM DUTY series is newly developed compact and general purpose HST. This HST is constituted with axial piston pump & motor of maximum working pressure 14.7MPa has characteristics such as epochal compact, light weight, high efficiency, high reliability, and cost effective. The structure with 6 basic model series of 3 framesize enables it to be used as all kind of small vehicles. In this paper, we explain the basic design concept, technical characteristics of this BD series with applicable cases.
1991-11-01
Technical Paper
911289
Yutaka Furukawa, Eiichiro Ikeda
We have successfully developed a light-loading no-stage variable speed power transmission using V-belt for agricultual and general industrial machines enabling easier manipulation and faster transmission than conventional V-belt transmissions. This paper describes the fundamental operation principle of the transmission, and reports the results of the experimentl studies. The V-belt no-stage transmission is a power transmission which allows the ratio of the revolutions on the input axis to that on the output axis to be controlled with no stage by changeing the winding pitch diameter of a single V-belt put on a variable width (variable speed) pulley. The new transmission we have developed (called VSW-type transmission) is characterized by the linkage of the open/close of driving and driven pulleys with the fundament al principle to reduce operation load during ratio change.
1991-11-01
Technical Paper
911286
A.M. Ibrahim, Y.M. Abdel-Rahim, I.G. Ibrahim
The paper presents approximate formulations for the thermodynamic properties of combustion products of any specified hydrocarbon fuel (CcHhOoNn) in air as functions of fuel type, equivalence ratio, temperature and pressure. Real gas virial equations of state for product species are incorporated in the analysis and their effects are included in the formulations. Results of the paper are compared with other detailed chemical equilibrium calculations for three diverse fuels (octane C8H18, methanol CH3OH and coal CH.17O.05N.02) under different conditions with satisfactorily agreement.
1991-11-01
Technical Paper
911287
Domenico Laforgia
A mono-cylinder engine was built, because of its costs and the semplicity of designing, as flexible prototype. A scavenging system with four ports, two by two simmetrical, was chosen to respect the modern theory of scavenging optimization. The scavenging flow was supplied by a carter-pump; it has been used as first experimental solution. The prototype has been entirely realised and the following experimental measurements have been carried out: the pressure in combustion chamber, in carter pump, in pipes and injection system, as well as the fundamental parameters of engine functioning.
1991-11-01
Technical Paper
911294
Robert Craven, James E. Smith
Balancing to date, of the Stiller-Smith Mechanism, has been for a symmetric configuration. If two pistons are moved closer to the center of the engine to minimize spatial requirements and also reduce weight, then the mass center of the inner mechanism no longer travels in a circle about the center of the engine. It is shown how the overall balancing of the engine is not compromised using the example of a small 8-cylinder engine. The effects of the non-symmetry on the performance of the linear bearing is presented and the resulting additional engineering concerns are discussed.
1991-11-01
Technical Paper
911293
Kazuyuki Shiomi, Hiroshi Mizuguchi
This paper deals with a method of isolating vibration which can be applied to four - stroke, inline, two-cylinder engines with an even firing interval of 360°. This new method effectively isolates 1-st order vibration by positioning engine components and mountings in a way that provides the engine with an oscillation center without the use of additional balancer shafts. The conditions required for the existence of such an engine oscillation center, its movement and the effectiveness of this vibration isolation method are theoretically studied. This method will then be applied to a lawn tractor.
1991-11-01
Technical Paper
911292
Kenji Nishida, Hisao Fukunaga, Kiyoshi Kimura, Yoshimi Osanai
The centrifugal-weight-type V-belt automatic transmission is widely used for the light engines of scooters and agricultural machines, etc. for being compact, efficient and comparatively cheap. The operating section of this centrifugal weight, which contains the metal weight coated with thermoplastic resins in its movable pulley, is lubricated with grease to provide stability and life (reliability) for its operation. However, the grease filling work not only requires a substantial number of man-hours but also various seal parts to prevent, during running, the grease from being splashed about by the centrifugal force and dust particles from intruding. To overcome these restrictions, research has been conducted on how to free the centrifugal weight from the grease by experimenting with various self-lubricant resin compositions as the coating materials for this metal weight.
1991-11-01
Technical Paper
911291
Kichiji Misawa, Tomoaki Ishikawa
The first hydrostatic transmission (HST) installed on a walk - behind lawn mower was introduced 1989. The HST is tiny and efficient. The HST unit weighs 3.1 kg, has a pump displacement of 2 cm3 and a maximum overall efficiency of 72 percent. Since the driving direction is limited to forward, the hydraulic circuit can be simplified. The hydraulic circuit is integrated to the aluminum die-cast transmission case. Operation of both drive and shift levers are converted to the stroke of one single shift cable. This integral operation mechanism enhances such original HST's characteristics as starting with less shock and smooth shifting. Consequently, operational ease of the mower has been drastically upgraded in various locations, especially on inclined surfaces and narrow areas where this type of mower is frequently used.
1991-11-01
Technical Paper
911298
H. Ochiai, K. Hataura
Aluminum radiators using the Nocolok Brazing Process developed by Calsonic Corp. have been mounted on passenger cars since 1985 due to high performance, lightening, and high reliability compared with copper radiators. In this announcement, we will report about the development process of aluminum radiators to achieve weight reduction 30 percent compared with conventional copper radiators and better performance in actual use condition. In application of aluminum radiators by the Nocolok Brazing Process to agricultural machinery, we performed the followings; 1) Evaluation of corrosion resistance (inner, outer) in actual environment. 2) Evaluation of pressure resistance, and vibration resistance in actual working conditions and establishment of optimum mount system. 3) Evaluation of cooling system performance in actual working conditions by using dynamometer.
1991-11-01
Technical Paper
911297
Robert S. Freeland, Fred D. Tompkins, Luther R. Wilhelm, Joe R. Sarten
A tire impact test method was developed to measure the natural frequency of vibration for lawn and garden rear tractor tires. Data from the tests illustrate how a tractor chassis outfitted with a particular set of tires responded after its rear tires were impacted from free-fall. The vertical impact response of four different tire sets are presented. Two commercially-available tire sets vibrated primarily about 4.4 Hz, and to a lesser degree about 72.5 Hz. Two experimental tire sets had a lesser fundamental natural frequency of vibration (3.4 and 3.6 Hz), and also vibrated to a lesser degree about 72.5 Hz. The fundamental natural frequency of the commercial tires fell into the zone where human tolerance to vertical vibration is minimal. The fundamental natural frequency of the two experimental tire sets remained below this zone.
1991-11-01
Technical Paper
911296
Hiroe Nakagawa, Kenkichi Fujii, Mitsuo Yamane
A sealed nickel-zinc battery has been developed to replace the sealed lead-acid battery which was the only battery available for powering an electric undergrowth mower (or a shrub trimmer, or a shrub cutter). The sealed nickel-zinc battery weighs approximately 60% of the weight of the sealed lead-acid battery for a given energy stored, with battery discharge performance at a high current drain, particularly at a low temperature, coupled with a somewhat longer cycling life in a repeated use with a high current drain and charging with a charger exclusively designed for this battery. Unlike the other nickel-zinc battery, this sealed nickel-zinc battery does not use mercury as an additive to the zinc electrode, and so is environmentally benign.
1991-11-01
Technical Paper
911295
Manabu Furubayashi, Naoyuki Soma, Teruo Nakada, Mitsuo Iwahara
The authors developed a new method to calculate engine exciting forces by solving equations of motion using measured angular velocity fluctuation at the flywheel of the engine. Vibration response of a powerplant to the calculated engine exciting forces can be obtained by rigid body frequency response analysis with NASTRAN program using the measured value of the powerplant moment of inertia and the mount rubber characteristics. Calculated acceleration levels of a powerplant by this method were in close agreement with the measured ones. This method can be applied to estimate a powerplant vibration mode and levels when such parameters as engine mount locations are changed. As examples, the effect of reciprocating mass and cylinder-to-cylinder variation of fuel delivery were quantitatively discussed.
1991-11-01
Technical Paper
911302
Debra Sue Creasy, Yukio Ishiuchi, Masaru Fujisaki
There has been an on-going effort to localize Japanese-developed and -manufactured ATV parts in the U.S.A.. In order to achieve this goal, the differences between Japanese and American raw materials, quality control, and production methods were analyzed. The information acquired in each of these areas was utilized to solve the problems created by those differences. As a result, great steps have been taken in the local procurement of ATV parts. Initially, Japanese raw material was investigated. The results of this investigation, coupled with the technical requirements of the axle, were used in the selection of several potential U.S. raw materials. The adopted testing method, “Rotating Beam Bending Fatigue Testing,” was utilized to evaluate and determine which U.S. raw material was best qualified for this application.
1991-11-01
Technical Paper
911301
N. Takahashi, Y. Hiraguchi
Laser welding is frequently applied to process small precision parts since it has high power density and focuses beam spot size smaller. In an automobile industry, the laser welding has been put to practical use for welding of chassis because of its small weld distortion, the other hand, parts of motorcycle which are produced by laser welding are very few. Because most of the chassis and engine are made of aluminum alloys which are difficult to laser weld due to the low absorptivity of aluminum in the wavelength range of commercial laser welding system.(1)* However, the laser welding is applied for a part assembled with press-formed parts. Exhaust Ultimate Power Valve (EXUP), one of the exhaust system for 4-stroke motorcycles which has a precision valve system developed by Yamaha.(2)
1991-11-01
Technical Paper
911299
Kaoru Kito, Kenzo Kawakita, Hiroshi Furukawa
Conventional automotive batteries have been used in agricultural equipment. However, these batteries do not necessarily respond to what the user actually needs. The following complaints are often heard: * Engines do not start after long-term off-season storage. * Inconvenient services, such as recharging, are required. * These heavy batteries have no place to hold on to and is hard to carry. These problems occur simply because regular automotive batteries are applied. To create a truly appropriate battery for this application, some extensive study of actual use of batteries in agricultural equipment have been conducted. A sealed maintenance-free battery that is perfectly suited to this application, requires no service maintenance work, and results in no messy acid leakage was developed.
1991-11-01
Technical Paper
911270
Domenico Laforgia
A new and unique four-stroke i.c. engine without the conventional crankshaft is described. A lobe plate, which moves the piston according to predictable laws of motion, transforms reciprocating movements into rotative ones. The idea derives from the observation of the structure and functioning of pumps with axial plunger whose units plungerod, moving, holds closely to a plate whose angle of inclination determins the motion characteristics and the value of the stroke itself. The new solution introduces a more efficient method of transferring power from a piston to a driveshaft. A peculiar configuration of engine block has been designed, in which pistons, purposely designed, transmit power to a purposely shaped disk. Each piston follows the shape of this disk during the revolutions. The cam provides a broad range of engine displacements using only one block, varying only the piston laws of motion according to the different disks used.
1991-11-01
Technical Paper
911271
Swati Athavale, P.R. Sajanpawar
The paper describes some modelling aspects in finite element analysis of a small four stroke air cooled gasoline engine components subjected to thermal and mechanical loading. The authors have developed parametric model generator for connecting rod using isoparametric element. By discribing parameters numericaly the connecting rod finite element mesh is generated very quickly. It has a provision of inclusion of oil hole model also, which itself is parametric in nature. Authors have developed methodology based on ANSYS Finite element package to introduce inertia loading on connecting rod model. The concept of model generator has been extended for analysis of crankshaft for small gasoline engine. Based on results authors suggest that parametric software must have provision for local refining in finite element formulation so that using submodelling techniques stresses can be predicted accurately after convergence of results.
1991-11-01
Technical Paper
911273
Mutumi Iwasa, Toru Saito
Authors have developed a function that automatically judges the relation among the individual adjoining surfaces constituting the frame body and make a finite-element model of a motorcycle frame body by generating a mesh with all the surfaces together. By integrating this function with the three-dimensional CAD system, a high-speed and simple auto-mesh system has been materialized. This has made it possible to substantially shorten the time required for preparation of a finite-element model and apply CAE at an early stage of design of complicated-shaped constructions.
1991-11-01
Technical Paper
911272
Kunio Noda, Nobushige Anzai, Manabu Furubayashi
Several techniques have thus far been scrutinized for the estimation of machine vibration originated with the engine. Nevertheless, there has existed no other way available than to conduct experiments to know the vibration level quantitatively, since such techniques available today are not accurate enough. Authors have thus pursued research and succeeded in working out a simulation method that is capable of estimating, at design stage, the vibration attributable to engine exciting force on machine structure, especially on the low frequency vibration, that in consequence caused the oft-occurrence of problems such as noise through the vibroaction of panels, as the engine is mounted on the vehicle frame via mounting rubbers. Authors then applied such method to selective engine mounts and validated a good agreement with the results obtained from the simulation and the life-test, even with the use of mount rubbers of varying characteristics.
1991-11-01
Technical Paper
911274
Yoshihiko Kawazoe, Shiping Zhang
It is the aim of this presentation to deal with an improved transfer matrix method for three dimensional vibration analysis of a reciprocating engine crankshaft system, so as to provide an efficient and convenient method for complex crankshaft system dynamic analysis. For different type of crankshafts, only the numbers and relative direction angles of the cylinders are required as input data besides the structural data. The theoretically predicted frequencies and mode shape agree well with the experimental results. In the case of dealt with a four-cylinder two-stroke small engine, five times exciting forces are of the most important which induce the crankshaft resonance. An effective and convenient general computer program for disign engineer to operate has been developed.
1991-11-01
Technical Paper
911275
Kunihiko Hosonuma, Yasuo Konishi, Yasushi Naitoh, Yoshinobu Yashiro, Hideaki Kawabe
Effect of base stock material, especially polybutene, on two-cycle engine oil performance was studied. At first, visible smoke tests were conducted, using test oils of different base stocks. Polybutene showed the best performance among the test oils. Then, piston detergency tests were performed. Test oil of higher molecular weight polybutene showed poorer results. In addition, piston deposits were analyzed and it was found that polybutene molecular weight was increased during the test. Piston detergency was discussed in relation with the increase in viscosity caused by increase in molecular weight. Finally, engine startability tests were carried out. Good correlation with viscosity was found only in test oils of same mineral base stock concentration. The increase in engine start torque was attributed to increase in polybutene viscosity caused by selective evaporation of the lower molecular weight portion.
1991-11-01
Technical Paper
911276
Shin-Tsun Lai, Jack P.M. Sheng, Cheng-Shyong Lin, Ron Sheng Lin, Chen-Yi Lin, Yo-Fu Shiau, Gibbs G.S. Huang
This paper discussed the results of the exhaust emission (HC, CO & Smoke) and lubricity of two stroke engines for motocycles. Three different displacements 150c.c., 125c.c. and 49c.c. air cooled type, two stroke engines were employed in this study. Results showed that the emission of HC and CO were not significantly changed by varying oil/fuel ratio, but the visible smoke could be reduced by leaner oil/fuel ratio. The HC and CO emission and visible smoke were reduced in the polybutene containing oils. Higher molecular weight polybutene were more effective for the reduction of smoke. In view of the lubricity performances, it was found that higher molecular weight polybutene caused the piston skirt scuffing and spark plug fouling problems, and also had a negative effect on piston cleanliness. The combination of low ash type additives with some ashless dispersants improved engine cleanliness and ring sticking.
1991-11-01
Technical Paper
911277
Mineo Kagaya, Mitsuaki Ishimaru, Hiroaki Ishii, Noboru Ishida
This paper describes a study of the effects of two cycle engine oil composition on biodegradability and engine performance. With increasing interest in environmental protection, it becomes important to develop an oil that would not harm the environment. Desirable requirement was the development of a biodegradable oil with performance suitable for outboard engines, motorcycles, chain saws, and all other types of two-cycle engines. In addition to biodegradability, two key points for the development of this oil were the selection of a base oil that provided outstanding thermal stability and the blending of ashless dispersants that offered excellent high-temperature cleanliness. The developed oil which is formulated with properly selected esters and dispersants showed better performance than current biodegradable oils in every practical use.
1991-11-01
Technical Paper
911278
A.J. Kiehn, G.E. Mackisoc, J.R. Wilson
In a variety of liquid and air cooled, gasoline 2-Cycle Engines, testing has suggested that performance of can be significantly influenced by the components used in 2-Cycle lubricants. A blend of anti-scuff, deposit control, and combustion modification additives in combination with carefully selected base oils is needed to produce an optimum 2-Cycle lubricant. Research has shown that Bright Stock, while being an excellent anti-scuff agent increases engine deposits and exhaust smoke. Use of polybutene (polyisobutylene) polymers or synthetic anti-scuff agents in place of Bright Stock has been found to be an effective means of controlling smoke while maintaining good anti-scuff performance. Use of polybutenes, however, may cause the formation of sticky deposits. Development of a synthetic, low smoke, high performance 2-Cycle Oil is reviewed. Incorporation of a combustion modifier in 2-Cycle Oils is also reviewed.
1991-11-01
Technical Paper
911279
Hirotsugu Okuse, Fukumitsu Kitauchi, Kozo Hashimoto
The running conditions of the connecting rod bearings for two-cycle engines have been made more critical recently than they were before, even after the rolling bearings, especially, the needle roller bearings were introduced for them. The bearing performance has to meet the running conditions reliably, which are even less lubrication, high temperature and high speed. This paper discusses the characteristics of the needle roller bearings based on the bearing test results, and two-cycle engine firing test results from a bearing manufacture's viewpoint, and also the development of the connecting rod large-end bearings to improve rotation speed and anti-seizure.
1991-11-01
Technical Paper
911280
Yoshinobu Yashiro, Kunio Takahashi
Two-stroke gasoline engine is lightweight, compact and has numerous advantages. However, because of its inherent engine configuration, engine oil is used as once-through system and is discarded, resulting in exhaust smoke in some occasions. In order to reduce the exhaust smoke, it is imperative to make improvement not only in engine itself but also in oil used. No standard method was available to evaluate engine smoke performance. This study was initiated to devise a simple evaluation method. In two studies reported here, evaluation of oil alone and evaluation of oil performance in actual engines are given. Following two facts were found as a result. The first item is the fact that oil can be evaluated by any actual engine performance evaluation method once the engine used and the method used are specified. The simplest and the most accurate method among the actual engine performance methods is the method to use the small two-stroke electric generator.
1991-11-01
Technical Paper
911281
Junichi Sagawa, Yukio Ikeda, Tohru Onuki
In recent high speed gasoline engines, piston's aluminum sticking to compresson rings has been an important issue for engine performance. To investigate the mechanism of aluminum sticking and evaluate sticking characteristics of piston/ring material and surface coatings, an aluminum sticking rig tester was developed and applied to duplicate the sticking phenomenon. Engine tests were also carried out based upon the result of rig test and the aluminum layer stuck to ring side face was metallurgically analysed by Electron Probe Micro Analyser. Among many surface coatings of piston rings including phosphate coatings, chromium plate, iron plate and MoS2 coating, it was demonstrated that MoS2 coating is very effective to prevent aluminum sticking at engine break in.
1991-11-01
Technical Paper
911282
Tomomi Machii, Minoru Hirahara
As the material for the swing arms of motorcycles, aluminum is becoming popular to reduce their weight in recent years. Usually their cast body and pipe arms are welded together. The new “weld-free swing arms” introduced in this paper, the adhesive and bolts are adopted for joining, and forged arms are used instead of the pipe. As advantages of forged arms, engineers are capable to design freely and styling designers to take fine key elements in consideration. The adhesive coupling has many advantages listed below: * Better appearance: No welding bead * Cost reduction: Less man hour and simplified jigs * Improved dimensional precision: No thermal strain caused by welding * Improved swing arm performance: Light and strong * Upgraded work environment Elimination of unpleasant elements * Easy work: No special skills * Predictable strength: No variation by welder's skill