Browse Topic: Lawn vehicles and equipment

Items (115)
A centrifugal clutch is used in many machines such as scooters, lawn mowers, outboard motor of boats, brush cutters, and so on. It may produce a shrill sound, similar to a brake squeal, when the clutch engages for starting. In this study, we have proved that this shrill sound, in another word, clutch squeal, is caused by the self-excited vibrations of the centrifugal clutch. And we have also clarified that the clutch squeal can be restrained by employing an asymmetrical shape for the clutch housing. The clutch squeal tends to occur when the centrifugal clutch becomes hot due to repetitive starting and stopping, which causes the friction coefficient of the friction material on the clutch shoe to increase. It is presumable that vibration on the clutch housing generated by the self-excited vibrations is the cause of the clutch squeal. In an attempt to clarify the cause of clutch squeal, we first measured the sound pressure of the clutch squeal and the vibration shapes of the clutch housing when the squeal occurred. Then, using the complex eigenvalue analysis, which is one of the finite element methods, we got unstable modes of the centrifugal clutch that could lead to self-excited vibrations. By conducting a comparative verification of each result, we have proved that the cause of clutch squeal is the higher frequency self-excited vibrations in the centrifugal clutch. And using the complex eigenvalue analysis, we gained the perspective that applying an asymmetric shape to the clutch housing is a prospective solution to restrain the generation of unstable modes, and this was verified by testing with an actual scooter.
Yamamoto, KoheiIwamoto, TatsuyaOtsuka, Takashi
Compact off-highway machines should be as maneuverable, versatile and energy-efficient as possible. Key to achieving these goals is the electronification of the working hydraulics. New mini excavators, wheel loaders and track loaders from the Eurocomach brand, which is part of the Italian Sampierana Group, demonstrates the improvements that can be gained by utilizing electrohydraulic pump control and software. Sampierana first launched the electronification of its working hydraulics on its six-ton mini excavators. “Our compact construction machines are used for a wide variety of jobs,” said Giuseppe Fabbri, technical manager at Sampierana. “Loading, excavating or digging should be very accurate or quick and productive to perform, as needed, and also support a wide range of tools - from shovels to hammers or mowers.”
Malimpensa, Mattia
Artificial intelligence (AI) has become prevalent in many fields in the modern world, ranging from vacuum cleaners to lawn mowers and commercial automobiles. These capabilities are continuing to evolve and become a part of more products and systems every day, with numerous potential benefits to humans. AI is of particular interest in autonomous vehicles (AVs), where the benefits include reduced cognitive workload, increased efficiency, and improved safety for human operators. Numerous investments from academia and industry have been made recently with the intent of improving the enabling technologies for AVs. Google and Tesla are two of the more well-known examples in industry, with Google developing a self-driving car and Tesla providing its Full Self-Driving (FSD) autopilot system. Ford and BMW are also working on their own AVs.
Much development in the automotive industry relates to the use of high-content ethanol blended fuels to reduce the emissions produced by on-road engines/vehicles. However, less research has been done on the effect of operating small off-road engines (SORE) on high-blend ethanol fuels without substantial modifications. Most manufacturers of such engines only certify proper operation on low content ethanol blends such as E10 (10% ethanol, 90% gasoline by volume). This paper focuses on the use of E77 fuel in a small off-road engine which is speed-governed. Such engines are commonly used in lawn mowers, small recreational vehicles, or other equipment. The exhaust emissions and performance of the engine were evaluated using the EPA 6-mode duty cycle for small recreational engines where testing and analysis followed the recommendations of SAE J1088. This test cycle consisted of operating the engine at steady state load points using a fixed engine speed. The performance of the engine was compared to a baseline, found using E10 fuel. Following this, the engine was tested using E77 fuel utilizing the original un-modified carburetor with the original size jet and modified jet openings to provide better fuel-air mixture when using the high-blend ethanol fuel. Details of the engine jet modifications and the resulting performance are provided.
Davis, GregoryMazzei, Arnaldo
With the growing increase in the use of lawn mowers, it is necessary to control the vibration and sound pressure levels to which operators are exposed during their workday. Noise hearing loss can affect individuals exposed to high Sound Pressure Levels (SPL). Workers using lawn mowers are part of this population. With regard to this equipment, another factor that must be considered is the occupational exposure of the vibration imposed on the operator. Occupational exposure to vibration in the hands and arms is associated with a variety of adverse effects on the health of the individual, being collectively known as the vibration syndrome in the hands and arms. Exposure to full body vibration for seated people is associated with an increased risk of degenerative injuries lumbar spine, disorders in the central nervous system, and possible damage to the digestive and genital / urinary systems. Therefore, the objective of this study is to evaluate the vibration and sound power level emitted by a tractor of this class, under different operating conditions, which are a combination of three parameters: vibration attenuators (engine block cushions), engine speed and a power take-off (PTO) of the tractor. The acoustics tests followed a methodology based on ISO 3744:2010 - “Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for essentially free field over reflecting plane”. The vibrations measurements are base on ISO:8041 “Human response to vibration - Measuring instrumentation”. From the obtained data, the occupational vibration indicators and sound power level were calculated, so that it was possible to compare the different conditions. When comparing the levels obtained in the tests with the ranges provided by the standards, it can be noted that for some conditions the levels of vibration exceeded the desired values, the same happens with noise.
Fiorentin, Thiago AntonioBeletatti, LucasPfleger, Murilo Henrique
A multi-position 4-stroke piston engine utilizing a novel rotary valve system was developed for handheld outdoor power equipment applications such as chainsaws, brush cutters, and string trimmers. The purpose of the project was to create a low-emission 4-stroke engine with 2-stroke performance levels including high RPM limits and power output. This was accomplished using a rotary valve system in lieu of the typical poppet valves of traditional 4-stroke engines. The prototype was then incorporated into a functional product for overall performance evaluation. Three prototype 45cc rotary valve engines were developed and tested in both real-world usage and on laboratory engine dynamometers to measure power output and emissions levels. The rotary valve system provided the ability to achieve high RPM limits without the risk of valve float, delivered improved volumetric efficiency, and exhibited lower vibration and noise levels with improved power density over traditional 4-stroke valvetrains. Additionally, the total valvetrain part count and complexity was greatly reduced over poppet valve cylinder head designs. This paper will discuss the goals of this exercise and the relative performance of the final prototypes.
Garrett, Norman H.Uddin, MesbahBergman, MikaelPurvis, GarrettVaseleniuck, DarrickCordier, Dan
The demands on improving the noise, vibration and harshness of the golf mowing machines are growing rapidly. Low frequency vibrations at the human touchpoints are one of the important factors leading to the discomfort of operators on these machines. In the present work, low frequency vibrations experienced by the operator of the golf mowing machine are reduced using finite element analysis (FEA) and validated by a physical test. Initially, testing observed high vibration at the command arm, where some of the operating controls are placed. FEA was carried out on a frame level assembly and the design was iterated to affect these vibration levels. The golf mowing machine considered in this work is powered by a gasoline engine, which is the source of excitation in the current scenario. The operational forces of the engine were measured by using blocked-force transfer path analysis at its mounts. The modal frequency response analysis used these calculated forces as an input excitation. The vibration levels predicted at the operator’s touchpoints through simulation showed a good match of the trend with the measured test response. The structural changes were done in simulation after studying modal participation factors for high vibration levels at a frequency of interest. Reductions in vibration levels at the command arm were validated through the test, which provided enhanced operator comfort.
Istalkar, DayanandHunt, Kevin
Illustrations used here are not intended to include all existing industrial or agricultural machines, or to be exactly descriptive of any particular machine. They have been picked to describe the principles to be used in applying this standard.
OPTC1, Personnel Protection (General)
The purpose of this SAE Recommended Practice is to provide a selection of disc wheels for industrial and agricultural application with a maximum of interchangeability. This is accomplished by establishing five groups of disc wheels, in each of which the hub mounting elements are common. These groups are designated 4 bolt, 5 in bolt circle; 5 bolt, 4.5 in bolt circle; 5 bolt, 5.5 in bolt circle; 6 bolt, 6 in bolt circle; and 8 bolt, 8 in bolt circle. Further, this document establishes an SAE part number and the maximum rated radial load for each standard wheel. In addition, the document requires the wheel manufacturer's name or trademark to be impression stamped on the wheel with location at the discretion of the manufacturer.
MTC8, Tire and Rim
The motorcycle terminology presented herein addresses two-wheel single track vehicles, as well as motorized three wheel cycles. Although two-wheeled, single track scooters and mopeds are similar to traditional motorcycles, they have many characteristics which differentiate them from motorcycles, and while some terms will apply, this Terminology addresses motorcycles specifically, unless otherwise noted. Likewise, some three wheel cycles may have some similar design features and share components with motorcycle, the dynamics and handling of three wheel vehicles differs from two wheel, single track motorcycles. The terminology presents definitions covering the following subjects: dynamics and handling of single track vehicles, motorcycle categories and types, motorcycle crash dynamics and technology, and in-depth crash investigations, motorcycle design and components, systems, and equipment, motorcycle operation, operational environments and hazards, rider protective equipment including helmets and clothing, rider behaviors, motorcycle safety, competitive motorcycle events and the specialized motorcycles used those events, key national motorcycle-related organization, selected phrases commonly used uniquely by motorcyclists, and related performance measures and selected test criteria. NOTE: Motorcycle emission terminology does not vary from automobile emission terminology and is not unique and therefore not included in this report.
Motorcycle Technical Steering Committee
Technology is continuously being developed to prevent self-driving vehicles from crashing. That technology could also be considered for other autonomous products. Collision avoidance in automated guided systems using a light detection and ranging (LIDAR) scanner has been studied for application in low-speed autonomous Honda Power Equipment products, such as self-driving lawn mowers. The automotive application of a LIDAR scanner for autonomous driving is used for obstacle detection and offline local area. Such delineations do not exist in areas where power equipment is used, such as grass fields; therefore, identifying object height and distance is a relatively new area. For this study, a small LIDAR scanner with a resolution of 0.01 m and a measurement range of 0.05 to 40.00 m was used on a Honda self-driving lawn mower. The measurement distance data was directly processed in the scanner, enabling the drive unit to obtain distance information during actual operation. Based on real-time data, collision avoidance and automated operation guidance could be achieved. Simplified object detection and an automated guided decision-making system were developed. System parameters were considered to optimize collision avoidance and the structure of the automated guided system. Field testing was performed at a dedicated test field facility, and the test condition was determined. Fences, tall grass, and ground levels were successfully classified during testing operation. Collision avoidance, running, and stop modes were identified by onboard LIDAR scan data. Based on the field test analysis, a developed autonomous system structure is suitable for lawn, snow, and future power equipment applications.
Hasegawa, ToshiyukiWians, Jeff
Farming has not been untouched by the IoT revolution. The relationships among field conditions, crops, and strategies for planting, irrigating, and harvesting are complex, yet vital for the success of the enterprise. Agricultural machines such as tractors, combines, mowers, and balers are key to smooth operations. Intelligent, addressable sensors on the machines and in the fields, enable farm managers to keep track of operations that are not only widely dispersed but also in motion.
The information in this SAE Recommended Practice has been compiled by Technical Committee 1 (Engine Lubrication) of the SAE Fuels and Lubricants Division. The intent is to provide those concerned with the design and maintenance of two-stroke-cycle engines with a better understanding of the properties of two-stroke-cycle lubricants. Reference is also made to test procedures which may be used to measure the chemical and physical characteristics of these lubricants.
Fuels and Lubricants TC 1 Engine Lubrication
In the process of developing small general purpose engines, it is necessary to obtain accurate engine usage information. Commercially available measurement systems created for this purpose have unfavorable characteristics, including limited flexibility and large physical size. A compact data logging device was developed to overcome these limitations, and it was used on several lawn mowers. A microcontroller controls the data logger and acquires data. The data logger also includes a vacuum pressure sensor, tachometer input, thermocouple inputs, and a GPS (Global Positioning System) receiver. The GPS receiver is used to provide machine position and velocity data, which is synchronized with the other measurements. The housing is compact (54 mm x 124 mm x 100 mm), so it can be mounted on most small engine-powered products. Setup of the data logger requires no significant engine or machine modifications, which reduces the time required to instrument a product for testing. Since the data logger is simple and compact, it was possible to deploy several loggers concurrently in different geographic regions. The acquired data was used to quantify the engine loading, engine start cycles, accessory clutch cycles, and movement of the machine. These results are being used to precisely define the usage and durability requirements for small engines. In the future, work will be done to expand the data logger’s capability.
Bejcek, Andrew
In order to fulfill future regulations regarding emissions and CO2 reduction, the small engine market inclines to migrate from carburetor systems to cleaner, more efficient electronic ignition controls and electronic fuel injection systems. When implementing such mechatronic systems in small engine applications, one has to consider specific boundary conditions like the lack of relevant sensors, limited possibilities in terms of space and of course the necessity to keep the costs as low as possible. Especially in the non-road mobile machinery (NRMM) segment, the absence of sensors makes it difficult to apply standard electronic control systems, which are based on engine related input signals provided by sensors. One engine related signal, which is even provided by the simplest engine setup, is some form of the crankshaft speed since it is essential for the functionality of the engine. In this paper, the potential of an electronic ignition timing control system based on this signal as well as experimental experiments are presented. A single cylinder lawn mower SI engine is used for the experiments, since it is representative for basic NRMM engine configurations. Under the restriction that the speed regulating centrifugal governor should not be manipulated, the potential of the electronic ignition control has been investigated with the focus on engine performance and noise emissions under transient load conditions.
Zisser, MichaelSchacht, Hans-JuergenStelzl, ReinhardSchweighofer, BernhardWegleiter, HannesSchmidt, StephanTrentini, JakobBanzhaf, Jan-PhilippGegg, Tim
Two-stroke engine keep-clean data is presented to demonstrate the deposit removal capabilities of a premium fuel additive. In this testing, the fuel additive was added as a top-treatment to a 50:1 blended fuel-oil mixture. Engine testing was conducted on an EchoTM SRM-265 (25.4 cc) string trimmer run under a standardized test cycle. Test measurements included piston deposits, ring deposits, and exhaust port blockage. In addition, a more complete data set was analyzed and several variables were investigated including: different base gasoline fuels, ethanol level (E0 and E10), additive dose (none, low, and high), and fuel stabilizer dose (none and high). Post-test inspection of engine parts using fuel additives showed a high level of clean surfaces, which maintained the engine at its original performance.
Parker, GarrettBartley, StuartNicholls, Michael
Two-stroke engines are used in several purposes, such as lawn mowers, chainsaws, power generators and for motorcycles in some dirt tracks competitions. In addition, small Wankel engines are used in snowmobiles, motorized paragliders and range extenders. Both types of engines are known for the great power produced per displacement, ideal for the purposes aforementioned, but its bigger emissions due to lubricating oil mixed with fossil fuels, such as gasoline, do not pass legislation's standards, which limits their use. In order to reduce emissions, tests with ethanol and castor oil, eco-friendly fuel and lubricant, respectively, will be presented to adequate these organic compounds to the engine's operation.
Lemos, Bernardo Luiz Harry DinizSalomão, Eduardo AbreuViana, Matheus Philipe RibeiroAmorim, Rogério Jorge
Google Earth is a geospatial browser produced by Google that allows interactive exploration of the world from data servers on the Internet. An integral part of Google Earth is a built-in “cache” that is stored locally on the user’s computer, and allows the user to later revisit previously viewed regions (even if the network link is disrupted or unavailable). The Google Earth cache is filled as the user interacts with Google Earth (i.e., flying and zooming the interface). The Google Earth Offline Cache Pre-loader (GEOCP) is a tool that allows users to specify a region to cache, and controls Google Earth to automatically and systematically fill the Google Earth cache. While connected to the Internet, the user specifies a latitude/longitude box, and a desired height above the ground. GEOCP then commands Google Earth to view the requested area in a lawnmower pattern, which has the side effect of bringing those areas into the Google Earth cache. When finished, the user is free to disconnect the network and continue to view the area.
Advances in unmanned underwater vehicles (UUVs) are providing government agencies and commercial organizations with new capabilities across a variety of mission requirements. However, many underwater vehicles only address specific criteria or support well-defined (and limited) niches. As an example, the Naval Sea Systems Command's (NAVSEA) Littoral Battlespace Sensing (LBS) system includes the LBS-G long-endurance glider to collect oceanographic data, but also needs the LBS-AUV for military applications.
This SAE Recommended Practice establishes the instrumentation and procedure to be used in measuring the operator ear sound level for engine powered equipment under 30 kW (40 bhp). The sound levels obtained by using this procedure are representative of the sound levels generated by the equipment under typical operating conditions. It is intended to include equipment such as lawn mowers, snow blowers, and tillers. It is not intended to include equipment designed primarily for operation on highways or within factories or buildings, or vehicles such as motorcycles, snowmobiles, and pleasure motorboats that are covered by other SAE Standards or Recommended Practices. This procedure does not cover handheld equipment such as chainsaws, leaf blowers, and trimmers. This SAE Recommended Practice may also be used when measuring the operator ear sound level of similar equipment powered by electricity or other power sources.
Small Engine and Powered Equipment Committee
Illustrations used here are not intended to include all existing industrial or agricultural machines, or to be exactly descriptive of any particular machine. They have been picked to describe the principles to be used in applying this standard.
OPTC1, Personnel Protection (General)
Developing countries, facing greater challenges related to air pollution, are enacting more stringent emission rules for small engines. Idle Air Control Valve [IACV] along with Electronic Fuel Injection [EFI] is widely used for emission control in the large engine automotive market. This combination is also considered as one of the best solutions to aid in reducing the tailpipe emissions from small engines. One regulatory board for small engine use in USA is the California Air Resource Board [CARB]. CARB has a separate small engine emission category for nonautomotive Small Off-Road Engine [SORE] consisting of off-road spark-ignition engines below 25 horsepower, including all small off-road engines such as lawn mowers, weed trimmers, garden and other maintenance utility equipment [1]. SORE emission regulations for the handheld equipment were initially implemented in 1995 with most recently Tier II reductions of exhaust emissions in 2010. The Gen_VII IACV was designed for use on smaller engines, such as in motorcycle applications (refer to Figure 1). The IACV is a stepper motor having a permanent magnet rotor integrated with a threaded drive mechanism that transforms rotary motion to linear motion. This actuator is a digitally controlled bi-polar, 2-phase, linear stepper motor designed to operate as an IACV. It's recommended to be electrically controlled using a full step bipolar L/R drive circuit operating from 7.5 to 14_Vdc. The IACV is required to work in extreme engine environments and has critical operational requirements. This paper presents some challenges and technical solutions in the design and implementation of this Gen_VII IACV. The development of the smaller Gen_VII stepper motor was a continuation of collaborative efforts from Continental location in Asia, Europe, and North America.
Dian, HongKun, ChenTao, ChengWeldon, CraigChristiaens, AloisJie, Ren
This paper introduces a research project on a spark ignition engine used in non-road applications. The aim is to illustrate the present situation as basis for comparison and to identify possible improvement potential in terms of performance, efficiency or exhaust and noise emissions. The study is carried out in two steps. First a standard walk-behind lawn mower is equipped with measuring instrumentation for recording the cutting forces and the engine variables during real world operation. The tests are carried out on three different lawn types and two different blade types are investigated. Consequently, in a second step the engine is analysed on the engine test bench in stationary and transient operating mode. A complete engine mapping is done regarding all relevant variables. Additionally to the outdoor tests, fuel consumption and engine out emissions are measured on the engine dynamometer. The recorded data enables a detailed analysis of the engine behaviour. Furthermore the load spectrum during real world operation is diagrammed and the most frequent load and speed points of the engine on the different lawn types are identified. Moreover the flyweight governor system and, closely connected with it, the carburettor behaviour of the engine is observed under transient conditions.
Edtmayer, HermannTrattner, AlexanderSchmidt, StephanKirchberger, RolandTrentini, JakobWeiglhofer, Johann
This SAE Standard applies to self-propelled off-road work machines. Included are the following categories: Earthmoving Implements and Attachments Forestry Road Building and Maintenance Specialized Mining Powered Industrial Trucks This SAE Standard does not apply to Agricultural Tractors as defined in ANSI/ASAE S390 although some SAE standards are also applicable to Agricultural Tractors. NOTE: Most standards relating to agricultural tractors and implements are developed by ASABE.
Machine Technical Steering Committee
Biomechanical Analysis of a Complex Dynamic Task via Integrated Motion Capture and 3DSSPP2009-01-22896/9/2009
Determining the biomechanical demand of tasks that involve a wide range of postures typically requires the use of motion capture techniques to accurately measure the range of body positions throughout the task. Although there is obviously motion involved in such tasks, a biomechanical analysis can be performed using quasi-static methods provided the tasks do not involve significant accelerations. One commercial software tool for performing such analyses is the Three Dimensional Static Strength Predictor Program (3DSSPP) produced by the University of Michigan. While the postural data obtained via motion capture methods can be manually input into 3DSSPP, this typically involves either the use of a two-dimensional projection of the three-dimensional visual image to estimate the joint angles, or the user may perform a visual comparison of an actual image of the task with the 3DSSPP image to obtain matching postures in the two programs. However, an automated data transfer method from the motion capture software to 3DSSPP is both more efficient and accurate. This paper presents an integrated method of motion capture and biomechanical analysis utilizing a software script for converting the data from version 1.1 of the Cortex motion capture software to a batch file for direct input into 3DSSPP. The application of this direct data input method was demonstrated by using it to analyze the physical demands of pulling the starter cord on two different models of lawn mowers.
Freyder, Dawn R.Metzler, Sandra A.Eiselstein, NickGreaves, John
This SAE Standard establishes performance criteria for towed, semi-mounted, or mounted and arm type rotary mowers with one or more blade assemblies of 77.5 cm blade tip circle diameter or over, mounted on a propelling tractor or machine of at least 15 kW, intended for marketing as industrial mowing equipment and designed for cutting grass and other growth in public use areas such as parks, cemeteries, and along roadways and highways. The use of the word “industrial” is not to be confused with “in-plant industrial equipment.” This document does not apply to: a Turf care equipment primarily designed for personal use, consumption, or enjoyment of a consumer in or around a permanent or temporary household or residence. b Equipment designed primarily for agricultural purposes but which may be used for industrial use. c Self-powered or self-propelled mowers or mowing machines.
OPTC1, Personnel Protection (General)
Illustrations used here are not intended to include all existing industrial or agricultural machines, or to be exactly descriptive of any particular machine. They have been picked to describe the principles to be used in applying this standard.
OPTC1, Personnel Protection (General)
Two-stroke engines have been normally used for power equipment such as bush cutters and lawn mowers because of their compactness and cost-performance. However, their exhaust smoke is often put in question for causing a poor working environment. Therefore, it is important to develop an environmentally friendly two-stroke engine oil. In this paper, the development of a two-stroke engine oil with low smoke performance and its evaluation results are reported. If dilution ratio of a two-stroke engine oil with gasoline is increased in order to reduce the exhaust smoke, the lubricity becomes poor because of the decrease of base oil ratio in the oil. A two-stroke engine oil that copes with both low exhaust smoke and anti-seizure performance for pistons, has been developed by using a carefully selected polymer ester. The oil showed excellent anti-seizure performance in actual engine tests. In addition, it was also confirmed that it had better low smoke performance than commercially available engine oils using an exhaust smoke test with an actual bush cutter.
KASAI, MoritsuguISHIKAWA, MotoharuNAKAJIMA, KatsuhikoMATSUOKA, Takeshi
This paper discusses an evaporative emissions control system which significantly reduces diurnal evaporative emissions in walk behind lawnmower engines equipped with float carburetors. The system also maintains engine startability, run quality, and a simplistic user interface. The system consists of low-permeation fuel line and a multi-layer fuel tank using an EVOH barrier as well as a carbon canister integrated in the lawnmower's push-handle and an Automatic Bowl Drain System (ABDS). A prototype of the system resulted in a 90% reduction in diurnal evaporative emissions when compared to a pre-regulation walk behind lawnmower using the CARB TP-902 sealed housing for evaporative determination test. This paper demonstrates a practical solution to reduce diurnal evaporative emissions and hydrocarbon running losses below the level emitted from a state of the art, float carbureted, walk behind lawnmower engine.
Bejcek, Andrew
This SAE Recommended Practice establishes the test procedures, performance requirements, and criteria necessary to evaluate minimum safety and reliability requirements of a children's snowmobile as identified in 1.2.
Snowmobile Technical Committee
Illustrations used here are not intended to include all existing industrial or agricultural machines, or to be exactly descriptive of any particular machine. They have been picked to describe the principles to be used in applying this standard.
OPTC1, Personnel Protection (General)
An Experimental Survey on the Emissions Characteristics of Non-Road Small S.I. Engines in China2003-32-00369/16/2003
There are not emission legislations for non-road small spark ignition engines in China so far. To formulate an appropriate one, an experimental investigation was firstly carried out in order to point out the state of the art of the exhaust emissions of non-road small spark ignition engines in China. 17 different engines were selected as representative of the most common non-road small spark ignition engines in China, including lawn mowers, generator and chain saws. Fourteen engines are four stroke and three engines are two stroke. All of them were not equipped with catalytic converter. After a run-in period, exhaust emissions such as HC, CO, CO2, NOX were measured according to different test cycles. Besides these, exhaust temperature, A/F in the exhaust and fuel consumption were also measured. The exhaust analyzers are HFID for HC, CLD for NOX, NDIR for CO and CO2. The specific exhaust emissions obtained under different test cycles were then compared with the EPA phase 2 limitations. It was concluded that non-handheld engines had more difficulty in complying with the corresponding limitations than handheld engines. For non-handheld engines, HC+NOX emission was the main problem. Finally, a four-stroke non-handheld engine was selected to do further research, to reduce its higher HC+NOX emission, different measures such as carburetor tuning, second air supply and catalytic converter were tried and favorable results were achieved. The specific exhaust emissions of CO, HC+NOX were reduced by 49.2% and 46.6% respectively.
Bin, JiaManqun, LinXicheng, YanYabing, Jing
This SAE Standard establishes performance criteria for towed, semi-mounted, or mounted and arm type rotary mowers with one or more blade assemblies of 77.5 cm blade tip circle diameter or over, mounted on a propelling tractor or machine of at least 15 kW, intended for marketing as industrial mowing equipment and designed for cutting grass and other growth in public use areas such as parks, cemeteries, and along roadways and highways. The use of the word “industrial” is not to be confused with “in-plant industrial equipment.” This document does not apply to: a Turf care equipment primarily designed for personal use, consumption, or enjoyment of a consumer in or around a permanent or temporary household or residence. b Equipment designed primarily for agricultural purposes but which may be used for industrial use. c Self-powered or self-propelled mowers or mowing machines.
OPTC1, Personnel Protection (General)
As long as people need to he in a machine to run a machine, operator stations will continue to become more operator-friendly. There have been obvious changes in off-highway vehicles over the last 100, or even 200 or more, years. For power, the equipment has evolved from horses to steam to gasoline then to primarily diesel. As far as a first step toward operator comfort, the wheels changed from wood to steel to steel rims with hard rubber casings then to pneumatic tires in the early part of the 20th century, which helped abate “the eyes of the operator rolling inside his head,” to paraphrase how one historian described the off-highway operator environment on The History Channel during a documentary on the history of the truck. Keeping in mind the revolutions mentioned above, it was not that long ago when off-highway operators were constantly exposed to the elements, and certainly, depending on the options afforded or desired by the consumer, some still are. However, whether the operator is snug inside a tinted-glass cab with environment control while listening to satellite radio or not, a comfortable seat is a must.
Broge, Jean L.
Since 1974, KUBOTA “B-Series Compact Tractors” have gained a high reputation all over the world mainly for their compact body sizes and versatile performances in mowing, transporting and landscaping. Recently KUBOTA developed the new B-Series Tractors, which consists of five models with PTO power ranging from 9.3 to 16.4 kW (12.5 to 22 HP) as shown in Table 1. Recently, models equipped with hydrostatic transmissions (HST) account for the majority of the 9 to 16 kW (12 to 22 HP) range tractor sales, because of ease of operation and higher operating efficiency. Accordingly we have equipped all five models with HST, while making the manual transmission available on only one model. We have increased the PTO horsepower to more than 14.9 kW (20 HP), while maintaining the compact body size. At the same time, we have added new features to enhance performance of the tractors' three major uses, front loader, mid mount mower, and rear implement operations. This paper discusses the technologies incorporated in the development of the higher horsepower models, the B2710 and B2910, as well as new features added.
Nishino, AkifumiTakekata, MitsuhiroMaezawa, KiyoshigeNakanishi, Kiyokazu
Results Of Temperature Controlled Autoignition Combustion Over The Hydrocarbons Emissions And Fuel Consumption At Light Loads In A 50 cm3 Two-Stroke Engine2001-01-185712/1/2001
Nowdays in the field of internal combustion engines research there is an important interest on a new combustion process that promise great advances in the reduction of fuel consumption and exhaust emissions. This paper describes the successful application of The Temperature Controlled Autoignition Combustion on a small (50 cm3) two-stroke engine tested under laboratory conditions. The engine is a commercial model, used to power scooters, chainsaws and lawn mowers. The paper also details the experimental setup, the particular problems associated to the small size of the engine, the operational conditions and the engine modifications required to make possible a stable and uniform Temperature Controlled Autoignition Combustion at light loads. Also the characteristics of new data acquisition software specially designed and tailored for this study are described. One of he weak points of this kind of engines is the strong irregularity from cycle to cycle that appears when operated at partial loads, which produce high unburned hydrocarbons emissions and a considerably increase in fuel consumption. As the experiment confirms, the Temperature Controlled Autoignition Combustion greatly improves this instability problem. Statistic study is presented to support this. As a result of the great number of test at different conditions the authors were able to determine the ranges of relevant parameters (air/fuel ratio, exhaust temperature, chamber wall temperature, etc.) in which it is feasible to run the engine under Temperature Controlled Autoignition Combustion . The results and curves obtained experimentally shows an important reduction in fuel consumption and exhaust emission of unburned hydrocarbons Finally, a discussion of the results is presented.
Sánchez, Carmen BarriosKindelan, Jesús Casanova
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