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Viewing 70801 to 70830 of 102495
1987-09-01
Technical Paper
871608
J. D. Summers, K. P. Self, G. L. McLaughlin
Tractive performance tests were performed with five I-3 traction implement tires on bermuda grass sod and McLain silt loam soil. Differences in the tires were lug angle, lug pattern and tire profile. Each tire was operated with three static loads and three inflation pressures. Net traction, towed force, load transfer, actual velocity and axle speed were measured. Pull-to-dynamic load ratio and wheel slip were calculated. Curves were fit to the data to describe tractive performance. Significant differences were found in the pull-to-dynamic load ratio of the five tires.
1987-09-01
Technical Paper
871609
R. W. Orme, J. S. Mutziger, E. L. Wegscheid
A STD Bus, PC-DOS based data acquisition system has been developed for collecting ride, function and fatigue data from field vehicles. The system is modular with a channel capacity of 8 to 32 channels when configured with a full set of conditioning modules. Several alternate storage media systems are available to provide efficient data storage and transfer to standard personal computer systems for analysis. A modest system extension expands the system to enable it to become a flexible development tool for closed-loop control concepts and algorithms.
1987-09-01
Technical Paper
871610
Takeyuki Kamimoto, Haruyuki Yokota, Haruki Kobayashi
The characteristics of diesel spray and flame in a quiescent atmosphere were studied as a function of injection pressure ranging from 30 to 110 MPa. Measurements included the spray form and Sauter mean diameter of a non-evaporating spray, the liquid phase penetration of an evaporating spray and the visualization of sooting zone in a flame. Experimental results show that high pressure injection improves the atomization and air entrainment of non-evaporating spray and that the liquid phase penetration of evaporating spray is hardly affected by injection pressure, demonstrating a promotion of evaporation with injection pressure. Visualization of the sooting zone in a flame made it clear that high pressure injection is advantageous in reducing soot formation and shortening the combustion duration.
1987-09-01
Technical Paper
871611
M. Takiguchi, P. Pichainarong, T. Matsushita, S. Furuhama
In high pressure hydrogen injection hot surface ignition engines under nearly all engine operating conditions combustion pressure vibration is generated just after ignition. As a result of many experimental investigations the true nature for the cause of this interesting phenomenon was found and are listed: (1) This phenomenon probably originates from the extremely high local rate of burning of the hydrogen-air mixture. (2) Accompaning the stronger combustion pressure vibration was an increase in engine vibration and noise with increase in NOx emission and higher piston temperature. (3) Longer ignition delay resulted in a steeper pressure-time diagram which resalted in a stronger combustion pressure vibration. (4) The phenomenon had negligible effect on engine performance. (5) The phenomenon can be prevented by premixing a ceratain quantity of hydrogen gas into the intake air stream. The result was a shortened ignition delay.
1987-09-01
Technical Paper
871604
Zhou Entao, Cao Xinmin, Zhou Shichang
Paper introduces a new type of small displacement sensor. It has the characteristics of high sensitivety, high pressure resistant, non-contact type etc. The sensor was used in measuring the displacement of the valve cone of a cartridge valve and the results were fairly satisfied.
1987-09-01
Technical Paper
871605
Russ Henke
The hybridization (1) of fluid power and microelectronics control technologies has created a dilemma for practitioners of both arts. On the one hand, we have tecnologists who have long treated fluid power applications on a “brute force” basis and are unaccustomed to the apparent finesse associated with microelectronics which are revolutionizing control in their domain. And on the other hand, we have microelectronics technologists who know almost nothing about the power transmission capabilities of fluid power-many of whom do not even care about its role as a basic productivity technology. The fundamental interfacing problem is getting these two groups to communicate, because microelectronic control of fluid power systems appears to be the wave of the future. It is likely that standard hydraulic or pneumatic energy trandsucing (2) components, in the classic sense of the term, will be “tailored” to specific applications by microelectronic controls superimposed on the power devices.
1987-09-01
Technical Paper
871606
Michael McKiernan, Thomas R. Lalk, Bill A. Stout, Stephen W. Searcy
The feasibility of using exhaust temperatures and injector nozzle needle lift duration to predict power output and fuel consumption of a diesel engine was investigated using an instrumented John Deere 4440 tractor. Using data obtained during a series of PTO dynamometer experiments, regression models were determined correlating the needle lift duration, exhaust temperatures, and engine speed with the parameters of interest. The models were subsequently tested under normal tractor operating conditions on a commercial farm. Fuel flow and engine power output were accurately predicted from engine speed and needle lift duration and both these variables could be measured using one needle lift sensor. Engine power estimation from exhaust temperature measurements proved unsatisfactory due to the slow speed of response to changes in engine load.
1987-09-01
Technical Paper
871607
Leonard L. Bashford, Kenneth Von Bargen, James H. Esch
In order to evaluate tractor performance, axle torque and speed are required to calculate axle power. The ability to develop torque in drive axles of agricultural tractors is dependent on dynamic axle load, the tire-surface interface and surface conditions. The factor limiting tractive performance could be any one of the forementioned variables. In large four-wheel drive tractors, equal torques in the front and rear drive axles are desirable under normal tractor operations to insure favorable drive train life. Presented in this paper is a summary of axle torques observed during operation of front-wheel assist and four-wheel drive agricultural tractors during performance evaluations on several different soil surface conditions.
1987-09-01
Technical Paper
871616
Svend Henningsen
Tests were performed on a single-cylinder direct-injection (DI) research diesel engine to investigate the influence of elevated combustion-chamber temperature on combustion performance. The test program examined the low-heat-rejection (LHR) approach by removing the coolant but without employing heat-insulated parts. Heat-release characteristics calculated from pressure-time histories were correlated with measured exhaust emissions. It was found that increasing temperature level decreases the ignition delay and consequently decreases the fraction of total fuel that burns in the premixed-combustion phase. Exhaust hydrocarbon, NOx and particulate emission were found generally to increase with increasing temperature. The premixed-combustion fraction is concluded not to be the main source of the increased emissions.
1987-09-01
Technical Paper
871617
N. A. Henein, Yukio Akasaka
Diesel engines have to face the prospect of running on heavy and/or low cetane fuels in the future because of the expected changes in base stock and demand. The effect of physical properties and composition of fuels on the ignition delay and cetane rating is examined. The experiments were conducted on fuels having a very wide range of physical properties and C.N., in a CFR engine. The ignition delay is measured under the standard ASTM D-613 procedure and under varying needle opening pressures, and coolant temperatures. The ignition delay of some fuels is found to be dependent on the physical properties and composition of the fuels in addition to the cetane number. The cetane rating according to ASTM-D613 procedure is found to take place under hot engine conditions with a single stage ignition process. At lower compression ratios, a two stage ignition was observed.
1987-09-01
Technical Paper
871618
Hiroshi Takahashi, Toshio Ishida, Kaoru Sato
In order to meet the demands for reduced emissions and improved fuel consumption, a subport-type variable swirl system (Isuzu Variable Electronic Economy Swirl, or IVES) was developed by Isuzu for medium- and heavy-duty direct-injection-type diesel engines. The main characteristics of IVES are: (1) It is simple in structure and only minor changes to the cylinder head are required. (2) Modular design is possible for three different swept volume engines due to the use of a common actuator and sensor. (3) The problem of air flow coefficient drop when swirl is varied has been successfully eliminated.
1987-09-01
Technical Paper
871619
Sohair F. Rezeka, Mohamed N. Saeed
Dynamic modeling of a diesel injection system is imperative to identify the forces applied to the system's elements and determine the conditions under which the system will be stable. The results of dynamic modeling are especially important for injection systems with different operating modes. This work uses a five-degree-of-freedom system to represent a diesel unit injector. The Bondgraph Method was used for formulating the kinematic and dynamic equations. The inputs to the system were the velocity of the cam follower and the pressure force exerted by the fuel on the plunger. The coefficients of the system's characteristic equation were then determined. Routh's criteria were considered to identify the region of stability for the unit injector.
1987-09-01
Technical Paper
871612
Noboru Miyamoto, Zhixin Hou, Akira Harada, Hideyuki Ogawa, Tadashi Murayama
Experiments on a large number of soluble fuel additives were systematically conducted for diesel soot reduction. It was found that Ca and Ba were the most effective soot suppressors. The main determinants of soot reduction were: the metal mol-content of the fuel, the excess air factor, and the gas turbulence in the combustion chamber. The soot reduction ratio was expressed by an exponential function of the metal mol-content in the fuel, depending on the metal but independent of the metal compound. A rise in excess air factor or gas turbulence increased the value of a coefficient in the function, resulting in larger reductions in soot with the fuel additives. High-speed soot sampling from the cylinder showed that with the metal additive, the soot concentration in the combustion chamber was substantially reduced during the whole period of combustion. It is thought that the additive acts as a catalyst not only to improve soot oxidation but also to suppress soot formation.
1987-09-01
Technical Paper
871613
Yukio Matsui, Kunihiko Sugihara
The purpose of this paper is to clarify the mechanisms of unburnt hydrocarbon (HC) emissions from a small direct - injection (DI) diesel engine. HC emission levels of small DI diesel engines are considerably higher than those of corresponding indirect - injection (IDI) diesel engines, even when sacless injection nozzles that are effective in reducing HC emissions are installed on them. In this study, analytical engine tests were performed to evaluate the relative significance of various potential sources of HC emissions from a small DI diesel engine equipped with sacless type injectors.
1987-09-01
Technical Paper
871614
Tadakazu Shiozaki, Takayuki Suzuki, Takashi Suzuki, Takeshi Matsumoto, Keizo Sugao
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.
1987-09-01
Technical Paper
871615
Gerhard Jahns, Klaus-Jürgen Förster, Paul W. Claar
An analytical technique is described to predict the performance of diesel engines. A set of equations are developed from an actual engine test or a performance map to predict fuel consumption as a function of engine speed and torque. The methodology uses a two-dimensional polynomial to predict fuel consumption as a function of engine speed and torque requiring nine engine specific coefficients or a one-dimensional polynomial as a function of engine torque requiring three coefficients only.
1987-09-01
Technical Paper
871549
Paul J. Steel
Quality management is rapidly-becoming accepted as a business strategy which extends across all disciplines or an organization. To accomplish this end, the process of evaluating needs, planning approaches, developing methods and implementating the resulting system has emerged as a challenge to companies in the western world. So, most companies have opted for short term approaches that have largely resulted in dismal outcomes. This paper deals with a systems management proceeds which extends from the identification of customer driven quality needs through the actual implementation of an integrated quality system targeted at these needs. Simply stated, the integrated quality system is the systems management process of doing what companies have wanted to do, but have been unable to do to improve their quality.
1987-09-01
Technical Paper
871522
Rafael Garcia, Ralph Mitchell, Tim Ford, James E. Watson, Richard L. Sauer, Duane L. Pierson
In 1985, the Man-Systems Division at the Johnson Space Center initiated a program for the development of a whole body shower suitable for operation in a microgravity environment. Supporting this development effort has been a systematic research program focused on four critical aspects of the design (i.e., human factors engineering, biomedical, mechanical, and electrical) and on the interfaces between the whole body shower system and the other systems to be aboard the Space Station (e.g., the water reclamation and air revitalization systems). A series of tests has been conducted to help define the design requirements for the whole body shower. Crew interface research has identified major design parameters related to enclosure configurations, consumable quantities, operation timelines, displays and controls, and shower and cleanup protocols.
1987-09-01
Technical Paper
871659
Phuoc Tran, Takashi Yamamoto, Yasukazu Baba, Mitsuru Hoshi
Influences of oil-flow and oil temperature on frictional torques of whole engine and main lubricating components were determined by motoring method. Oil-flow rate, temperature and pressure in main lubricating pathes were directly measured under the same conditions. Oil-flow rate and frictional coefficient of crankshaft system were estimated by theoretically analysing Reynolds’ equation. Experimental data were discussed based on oil-flow analyses in lubricating system. Engine frictional torque becomes smallest when the engine is supplied with an optimum oil-flow rate, 2.5 - 3.5 1/min where the ratio of oil-flow rate is 10 - 20 % in crankshaft system, 30 - 40 % in a piston-connecting rod system, and 50 - 60 % in valve system. The optimum oil-flow rate which minimises the frictional torque is 1 - 2 1/min for crankshaft and piston-connecting rod systems, and 3-4. 1/min for a valve system.
1987-09-01
Technical Paper
871660
Paul W. Claar, Pradip N. Sheth
A modal analysis methodology is presented for multi-degree-of-freedom articulated machinery and vehicles. The analytical technique formulates the eigenvalue problem for linearized, constrained dynamical systems during steady-state motion or at a static equilibrium position. The technique is implemented into a computer simulation program to compute the system modal properties. The system eigenvalues and eigenvectors are combined with the system geometrical transformation data to yield the system transfer function ratios for the generalized coordinates and points of interest, as well as the mode shapes. In turn, the frequency response magnitudes and phase angle shifts for a specified frequency range are computed from the system transfer functions.
1987-09-01
Technical Paper
871658
Chen Changyou, F. J. Wallace
As a predictive model for the uniflow scavenging process, a phenomenological model has been suggested. Based on jet mixing and propagation, this model can give an approximate description of velocity and concentration fields, thus obviating the uncertainty of the thermodynamic models. The unsteady jet model is soundly founded on the conservation laws of mass, momentum and energy for compressible flow. A comparison between the computational and experimental results of an opposed-piston two-stroke engine demonstrates good agreement. The experimental work on a simple water rig has been done. It also validates that the unsteady jet model is satisfactory.
1987-09-01
Technical Paper
871657
Chen Changyou, F. J. Wallace
As a non-predictive model of the scavenging process, a generalized thermodynamic model has been suggested. This model can give a thermodynamic description for any possible scavenging process. Having specified a history of the scavenging process, this model is suitable for all scavenging systems including cross, loop and uniflow scavenging schemes. For the simplified isobaric and isochoric model with respectively constant coefficients of intake and discharge proportions during different scavengine phases, analytical solutions for this model have been obtained. From these, all existing models with the isobaric and isochoric assumptions can be derived.
1987-09-01
Technical Paper
871663
Donald H. Lenhert, Maarten van Swaay
Recent trends toward the application of microprocessor technology for the control of hydraulic systems have made it necessary for the Hydraulic Control Specialists to expand their skills to include this new technology. This paper has been written to introduce designers of Hydraulic Systems to the basic functional building blocks, so that they may understand and then utilize this relatively new technology. After a brief introduction and a comparison of the relative merits of analog and digital systems, the paper proceeds with a review of terminology. Then basic hardware and software components of a typical computer system are described. Finally, a typical semiconductor microcomputer is discussed, with emphasis on voltage, current levels and underlying logic.
1987-09-01
Technical Paper
871664
Russ Henke
The intent of this paper is to provide hydraulic and electronic technologists an overview of the load-control-power loop intrinsic to hybrid microcomputer-hydraulic systems. This paper shows the relationships between machine loads, load variables,-interfacing loads with control systems by means of sensors/transducers; how to achieve sensor compatibility with the microcomputer; how signals are passed to and from the control computer; interfacing analog and digital signals with fluid power control components; fluid power actuator-load interaction.
1987-09-01
Technical Paper
871662
Jack Birch
The two dimensional curve fitting technique presented in this paper shows how a smooth curve can pass exactly through the input data points. The mathematical analysis is given with supporting figures. An example is supplied for application to a Monte Carlo based Automotive Assembly Variation Analysis.
1987-09-01
Technical Paper
871661
Paul W. Claar, Liansuo Xie
A computer methodology is presented that relates the dynamic response of a geometrically constrained, articulated mechanical system to changes in the design variables. The purpose of the methodology is to obtain the optimum design under dynamic conditions. The methodology finds the eigensolution to the linearized system equations of motion and then computes the rates of change of the eigenvalues and eigenvectors with respect to the system design variables. The design is modified to improve the system dynamic characteristics based on the sensitivity of the design variables changes. This methodology is demonstrated by evaluating the sensitivity of the natural frequencies and modes of vibration for an agricultural tractor-trailer system with changes to vehicle parameters for reduced ride vibration levels.
1987-09-01
Technical Paper
871668
George F. Alexander
The D8N track type tractor at 213 kW (285 horsepower) was developed to provide a machine with large tractor features, yet carefully sized to be transported easily. In addition to incorporating the design features of Caterpillar's other large elevated sprocket tractors, the D8N has been equipped with a unique new steering system that represents the latest advancement in crawler tractors: powered differential steering. This paper discusses the design features of the tractor and its new steering system.
1987-09-01
Technical Paper
871667
Rick Hall
The application of technology, through computer-aided engineering (CAE) concepts, to the design, development and manufacture of new products is exemplified in the new J I Case Model 688 hydraulic excavator. Computer-aided design (CAD), computer-aided testing (CAT) and computer-aided manufacturing (CAM) techniques were employed in developing the new product to meet ever-increasing industry demands placed on manufacturers for reliability, durability, serviceability, efficiency and operator comfort. This paper discusses and summarizes this development history.
1987-09-01
Technical Paper
871666
Walter H. Trask, Tom Crane, Randy Stemp
The LTL-900 Transi-Lift crane features front and rear crawler-mounted load platforms connected with a hoist-supporting five foot diameter pipe section. The pin-together main boom is available in lengths up to 400 feet and completely disassembles for ease of transport to and from the jobsite. The crane requires three operators and can hoist, boom, swing and travel simultaneously with maximum loads. Upending, moving and setting large refinery vessels is facilitated by the mobility of the crawler-supported crane on unprepared surfaces. Up to 1000 tons of 36 ton concrete beams or equivalent are required as counterweight to develop the ANSI B30.5 approved capacities.
1987-09-01
Technical Paper
871672
Bert-Inge Bertilsson, Lars Gustavsson
The paper presents the development and experiences of the multifuel TM101G engine. The standard TD101G engine, which is a turbocharged, direct injection engine with a displacement of 9.6 litres, was modified and equipped with two separate injection systems. Diesel fuel was used to ignite the alcohol. Performance and endurance tests were carried out, together with emission measurements. Twenty trucks and buses run on methanol or ethanol were involved in a field test. Fuel consumption and oil analyses were followed up.