A Study on Noise Test and Control of Combine Harvester

2014 ◽  
Vol 971-973 ◽  
pp. 324-328
Author(s):  
Yao Ming Li ◽  
Pan Sun

Faced at the present situation that the noise level of most combine harvesters was generally higher than the national standard limit in our country, experiments carried out to reduce the driver's ear noise, which chosen 4LZ-5.0E type tracked combine harvester as experimental prototype. The method of noise sources separation was used to test the whole machine on different working conditions. Based on the contribution analysis to obtain the contribution of main working parts for the driver's ear noise and identify the main noise sources. Through designing the reasonable structure of sound insulation for engine and installing the sound insulation plate on the left of driver, testing results showed that the noise of the driver's ear was reduced 3.1dB (A).

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Bing Yang ◽  
Yan Liu

A ring-plate-type cycloid speed reducer is one of the most important reducers owing to its low volume, compactness, smooth and high performance, and high reliability. The vibration and noise tests of the reducer prototype are completed using the HEAD acoustics multichannel noise test and analysis system. The characteristics of the vibration and noise are obtained based on coherence analysis and the noise sources are identified. The conclusions provide the bases for further noise research and control of the ring-plate-type cycloid reducer.


2011 ◽  
Vol 338 ◽  
pp. 259-262
Author(s):  
Hong Wang

As an important part of combines, hydraulic system has become one of the main symbols of representative of the technology level. As acreage is extensive in China, climate, soil and other environmental factors are big difference, and inter-regional economic conditions are unbalanced, China's combine harvesters have more varieties and strong regional. From the present situation of combines in china, the hydraulic systems were introduced, their characteristics were analyzed,. a reference was provided for OEMs to use the hydraulic system Practically and the development trends of combine harvester were pointed out.


Water Policy ◽  
2014 ◽  
Vol 17 (3) ◽  
pp. 423-440 ◽  
Author(s):  
Lei Wu ◽  
Tong Qi ◽  
Dan Li ◽  
Huijuan Yang ◽  
Guoqing Liu ◽  
...  

The surface water of 10 major river systems across China has been under intermediate pollution with striking eutrophication problems in major lakes (reservoirs). More data from the Ministry of Environmental Protection of China showed that underground water in 57% of monitoring sites across Chinese cities was polluted or extremely polluted. Rural water pollution, the rising number of incidents of industrial pollution, outdated sewerage systems, and the overuse of pesticides and chemical fertilizers also endanger the health of rural inhabitants in China. Nearly 0.2 billion rural residents could not use drinking water in accordance with the national standard, and there were reports of ‘cancer villages' and food-borne diseases (cancer village refers to a village where a certain proportion of its inhabitants suffer from the same kind of cancer or where there is a hike in cancer incidence in that area). This study aims to raise awareness of the prevention and control of water pollution and to propose a set of national research and policy initiatives for the future safety of the water environment in China.


1969 ◽  
Vol 34 ◽  
pp. 368-384 ◽  
Author(s):  
Sebastian Payne

In recent discussions of the origins and process of animal domestication (Reed, 1961, Zeuner, 1963), both authors rely on two kinds of evidence: on the one hand, the present distributions and characteristics of the different breeds of whatever animal is being discussed, together with its feral and wild relatives, and, on the other hand, the past record, given by literary and pictorial sources and the bones from archaeological and geological sites. Increased recognition of the limitations of the past record, whether in the accuracy of the information it appears to give (as in the case of pictorial sources), or in the certainty of the deductions we are at present capable of drawing from it (this applies especially to the osteological record), has led these authors to argue mainly from the present situation, using the past record to confirm or amplify the existing picture.Arguing from the present, many hypotheses about the origins and process of domestication are available. The only test we have, when attempting to choose between these, lies in the direct evidence of the past record. The past record, it is freely admitted, is very fragmentary: the information provided by the present situation is more exact, ranges over a much wider field, and is more open to test and control. Nevertheless, the past record, however imperfect it is, is the only direct evidence we have about the process of domestication.


2021 ◽  
Vol 64 (4) ◽  
pp. 1247-1258
Author(s):  
Yang Li ◽  
Lizhang Xu ◽  
Zhipeng Gao ◽  
En Lu ◽  
Yaoming Li

HighlightsThe relationship of vibration and header loss was studied by multi-point vibration measurement and loss collection test.There was an approximately linear positive correlation between total header vibration and total rapeseed header loss.The header frame was analyzed and optimized through modal simulation and testing.The total rapeseed header loss of the improved header was reduced by 33.2% to 46.9%.Abstract. In view of the current large rapeseed header losses of rape combine harvesters, the effects of the header on rapeseed header loss were studied from the perspective of vibration. First, the vibrations at various measuring points on the header during rape harvest were studied using a data acquisition and analysis system while performing collection tests of rapeseed header loss with the sample slot method. The relationships between total header vibration and total rapeseed header loss and between vertical cutter vibration and rapeseed vertical cutter loss were shown to have a positive correlation, and they all increased with the increase in engine speed. Vertical cutter loss accounted for 31.2% to 42.4% of the total rapeseed header loss. Modal analysis and optimization of the header frame were then performed by simulation and test. The natural frequencies of the first-order and second-order modes of the optimized header were increased, and the possibility of resonance with other working parts was eliminated. Finally, the improved header was tested during rape harvest. The results showed that the total vibration of the improved header was reduced by 19.9% to 43.9%, and the total rapeseed header loss was reduced by 33.2% to 46.9%. The vertical cutter vibration was reduced by 30.5% to 49.8%, and the rapeseed vertical cutter loss was reduced by 20.8% to 34.7%. In addition, the vibration and rapeseed loss of the improved header had relatively slow rates of increase with the increase in engine speed. The method of reducing rapeseed loss by reducing the header vibration achieved an obvious and positive effect. Keywords: Frame optimization, Modal analysis, Rape combine harvester, Rapeseed header loss, Vibration.


2020 ◽  
Vol 15 (01) ◽  
pp. 17-21
Author(s):  
J. Weinzierl ◽  
W. Wieland

In den Regelwerken zum passiven Schallschutz von Umfassungsbauteilen wird das erforderliche Schalldämm-Maß der Fassade als Einzahlwert entsprechend dem Bewertungsverfahren nach DIN EN ISO 717-1 [1] ermittelt. Um die spektrale Zusammensetzung verschiedener Lärmquellen und die frequenzabhängige Schalldämmung von Fassadenbauteilen zu berücksichtigen, werden in den einschlägigen Regelwerken Korrektursummanden bzw. Spektrum-Anpassungswerte verwendet. Im folgenden Beitrag wird der Einfluss verschiedener Außenlärmspektren und frequenz- abhängiger Schalldämm-Maße auf den Innenpegel diskutiert. Insbesondere werden die Unterschiede zwischen Holz- und Massivbauweise bezüglich des Schutzziels bzw. des Innenpegels betrachtet. Die Untersuchungen zeigen, dass keine generelle Differenzierung zwischen Leicht- und Massivbauweise erforderlich ist. Für hochschalldämmende Leichtbaukonstruktionen mit einem Ctr,50–5000 < –8 dB wird jedoch ein Korrekturterm für das erforderliche Fassaden-Schalldämm-Maß zur Sicherstellung des Schutzziels vorgeschlagen. &nbsp; &nbsp; Summary In the regulations for passive noise protection of surrounding components, the required sound reduction index of the facade is determined as a single value according to the assessment procedure according to DIN EN ISO 717-1 [1]. In order to take into account the spectral composition of different noise sources and the frequency-dependent sound insulation of facade components, correction summands or spectrum adaptation values are used in the relevant regulations. The following article discusses the influence of various outside noise spectra and frequency-dependent sound insulation measures on the inside level. In particular, the differences between wood and solid construction were considered with regard to the protection goal and the internal level. The investigations show that no general differentiation between lightweight and solid construction is necessary. For highly sound-insulating lightweight constructions with a Ctr, 50–5000 <-8 dB, however, a correction term for the required facade soundproofing dimension to ensure the protection goal is proposed. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;


2013 ◽  
Vol 753-755 ◽  
pp. 1382-1385
Author(s):  
Xin Wang ◽  
Han Fu ◽  
Du Chen ◽  
Shu Mao Wang

Harvesting speed is a key factor that influences working quality, utilization and harvest efficiency of the working process of grain combine harvester. In order to solve multi-objective control and poor anti-interference ability of measurement system in combine harvester, this paper uses optimization theory and error analysis theory to integrate analyze multi-source disturbance of data which is acquired in measurement and control system. The optimum working state control algorithm which proposes by this paper has better robust and anti-interference features, and what is more, it can be targeted by low yield loss, high productivity and low power cost. It provides theoretical basis and data support for the domestic agricultural harvesting machine, which also is an effective means to heighten the automatic level of the agricultural information technology. Keywords: Grain Combine harvester; Multiple control strategy; Anti-interference ability


2019 ◽  
Vol 49 (2) ◽  
pp. 85-93 ◽  
Author(s):  
G. E. Chepurin ◽  
A. P. Tsegelnik

The paper presents substantiation of the rational use of combine harvesters’nominal throughput when threshing grain crops with the yield ranging from 0.8 to 5.0 t/ha and over. The main factors that determine nominal throughput of combine harvesters and their operational indicators are identified. The structure andcontents of thetechnological passport of combine harvesters are substantiated, and the algorithm of effective determination of their key operational indicators, based on the passport, are developed. These indicators depend on harvesting technology, grain crop yield, the share of non-grain part in the threshed grain bulk, the coverage of swath headers and direct-cut headers, and the operating speed of combine harvesters. The definition of the term “technological passport of the combine harvester” is given. Maximum and minimum allowable grain crop yield is established for the rational load of combine harvesters threshing at the standard operating speed of7.5 km/hrecommended by the Ministry of Agriculture of theRussian Federation. The existing methods make it possible to determine the operational efficiency of high-performance machinery by operational costs. However, they do not take into account the shortage of human resources when determining production cost of the threshed grain. As a result of the research conducted, the algorithm and techniques of determination of actual grain cost when harvesting grain crops by direct combining and swath harvesting methods are developed taking into account the need in combines of an i-class and combine operators. Production cost of grain threshed on the area of1000 hectarescalculated by the techniques developed, allows to define the minimum estimated and actual grain cost for an i-class combine harvester by direct combining and swath harvesting methods.


2020 ◽  
Vol 12 (1) ◽  
pp. 38-54
Author(s):  
Bikash Adhikari ◽  
Anmol Parajuli ◽  
Prakash Adhikari

Ponds in Kathmandu were constructed to feed the sub surface aquifers of stone spouts and dug wells at all seasons. The study focuses on how the ponds have been saved, reduced in size or completely lost. The causes behind the degradation of ponds are forces of intervention and disturbances that lead to the loss of the originality, quality and quantity of ponds throughout its timeline. Out of eight existing ponds in the study area, 10 samples were taken from eight different ponds for quality assessment. The historical significances and status, uses as of 2019 are tabulated based on field survey. The paper focuses on the study of pH, Total Solids, Electrical Conductivity, Ammonia, Nitrate, Phosphate, Ammonia, Dissolved Oxygen, Biological Oxygen Demand, Total Organic Matter, Chlorophyll, E. Coli, and dimensions of existing ponds. The physical, social stresses and lack of regular inspection of ponds have contributed to their degradation. However, the existing ponds require sustainable management. Proper safeguarding mechanism should be developed for the regular aeration of water in the ponds such as fountains so that the ponds have more dissolved oxygen eliminating faulty smell and control fish death.


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