Põllumajandusmasinate katsestend
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Kuupäev
2018
Kättesaadav alates
Autorid
Kelgo, Kaspar
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Tänapäeva põllumajandus- ja metsandusvaldkond on väga mitmekesise tehnikatasemega
ning igapäevaga toodetakse üha rohkem eriseadmeid ning töömasinaid, mis aitavad kaasa
valdkondade arengule. Suurenevate tootmismahtude tõttu valmistatakse järjest suuremaid
ja raskemaid seadmeid, et optimeerida tööjõudlust ning vähendada ajakulu. Suurte
tootmismahtude tõttu on tootmisettevõtetel vajalik kasutada eriseadmeid ja katsestende,
mille abil koostada või katsetada toodetud töömasinaid ja –seadmeid, et veenduda
tootmiskvaliteedis ning tagada seadmete töökindlus. Kirjeldatud eriseadmete puhul on
tegemist seadmetega, mis juhivad ja käitavad töömasinat nii nagu traktor, kuid seadmete
ja katsestendide parameetrid ja abisüsteemid on kohandatud tootmisettevõttele sobilikuks.
Suurte ja raskete seadmete kasutusele võtmisega kaasneb aga piirang seadmete
käitamiseks kasutatavate traktorite rakendamisel. Raskemate töömasinate kasutamine
vajab ka suurema massiga traktorite kasutamist, et säilitada traktori juhtimiseks ja
kasutamiseks vajalikud tingimused. Põhiline probleem on suurte seadmete tõstmisel ja
transportimisel, nimelt seadme suure massi tõttu võib traktori kaalujaotus muutuda sellisel
viisil, et traktori ratastel väheneb haardevõime pinnasega. Haardevõime taastamiseks
kasutatakse erinevaid traktori massi suurendavaid lahendusi, kuid see suurendab ka
traktori rehvide ja muude tugiosade koormusi. Täpsemalt suurenevad pinnasesurve ning
koormus rehvidele ja telgedele ning väheneb traktori kasutusmugavus.
Käesoleva töö raames on uuritud töömasina ja –seadme tõstemisel tekkivaid koormusi
traktori rippsüsteemis ning lisaks on uuritud kaalujaotuse muutumist. Leitud koormuste ja
muutuste põhjal töötati välja matemaatilised seosed ja võrrandid, mida saab rakendada
katsestendide abisüsteemides ning täiendavalt ka töömasinate ja –seadmete
projekteerimisel, et arvestada seadme massist ja raskuskeskme asukohast tulenevat
kaalujaotuse ja koormuste muutumist. Käesolevas töös on projekteeritud katsestend, mille
abil saab katsestada põllu- ja metsatöömasinaid ning lisaks on katsestend varustatud
abisüsteemidega, mis rakendavad antud töös leitud kaalujaotuse ja rippsüsteemi
matemaatilisi seoseid.
Nowadays agricultural and forestry field has a varied technical level and new work machines and special devices that are made daily and are helping to develop those fields. Due to increasing production volumes larger and heavier machines are produced in order to optimize performance and decrease time consumption. In turn larger production volumes lead companies to a need of using special equipment and test benches, which help to construct or test produced machines and devices in order to insure and verify their production quality and reliability. Described special devices are devices that control the machine like a tractor, while its parameters and support systems are designed for the company. Using big and heavy equipment leads to limitations in what tractors can be used for a specific device. Heavier equipment needs heavier tractors in order to maintain necessary conditions needed for steering and using the tractor. The main problem is lifting and transporting heavy devices. Namely the weight balance of the tractor and device can change in a way that the wheels of the tractor can lose grip with the ground. In order to restore grip, different weight adding solutions are used, however adding extra weight also strains tyres and other parts. Namely the surface pressure and strain on the tyres and axles increases which leads to decreasing usability of the tractor. This thesis researches strains in tractors three-point linkage and the change in weight balance when lifting work machines and other devices. Mathematical relations and equations were made based on found loads and changes in weight balance which can be used by the support system of the test bench and also before designing work machines and devices so the designer can take the weight, the shift in weight balance and the changes in loads into account. This thesis designs a test bench which helps to test agricultural and forestry equipment. Moreover the test bench is equipped with support systems that implement the mathematical relations made in this thesis.
Nowadays agricultural and forestry field has a varied technical level and new work machines and special devices that are made daily and are helping to develop those fields. Due to increasing production volumes larger and heavier machines are produced in order to optimize performance and decrease time consumption. In turn larger production volumes lead companies to a need of using special equipment and test benches, which help to construct or test produced machines and devices in order to insure and verify their production quality and reliability. Described special devices are devices that control the machine like a tractor, while its parameters and support systems are designed for the company. Using big and heavy equipment leads to limitations in what tractors can be used for a specific device. Heavier equipment needs heavier tractors in order to maintain necessary conditions needed for steering and using the tractor. The main problem is lifting and transporting heavy devices. Namely the weight balance of the tractor and device can change in a way that the wheels of the tractor can lose grip with the ground. In order to restore grip, different weight adding solutions are used, however adding extra weight also strains tyres and other parts. Namely the surface pressure and strain on the tyres and axles increases which leads to decreasing usability of the tractor. This thesis researches strains in tractors three-point linkage and the change in weight balance when lifting work machines and other devices. Mathematical relations and equations were made based on found loads and changes in weight balance which can be used by the support system of the test bench and also before designing work machines and devices so the designer can take the weight, the shift in weight balance and the changes in loads into account. This thesis designs a test bench which helps to test agricultural and forestry equipment. Moreover the test bench is equipped with support systems that implement the mathematical relations made in this thesis.
Kirjeldus
Magistritöö
Tootmistehnika õppekaval
Märksõnad
magistritööd, traktor, tootmine, optimeerimine, põllumajandusmasinad