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земледелия, на вырубках и гарях совместно с семенами трав с обязательным предварительным рыхлением верхнего слоя почвы. Возможны другие варианты.
Библиографический список
1. Бартенев И.М., Родин С.А. Экологизация технологий и машин лесного комплекса. Пушкино: ВНИИЛМ, 2001. 88 с.
2. Бартенев И.М., Сухов И.В., Вершинин В.И. Технология сплошной обработки почвы под культуры дуба на вырубках // Лесное хоз-во. 1995. № 4. С. 42-43.
3. Белостоцкий Н.Н. О производстве культур саженцами с закрытой корневой системой // Лесное хоз-во и лесная пром-сть. 1979. № 3. С. 30-32.
4. Бирцева А.А. Густота посевов и качество посадочного материала с закры-
той корневой системой. Л., ЛенНИИЛХ, 1986. С.34-38.
5. Денисов С.А. Лесоведение. Естественное возобновление леса. Йошкар-Ола: МарГТУ, 2004. 67 с.
6. Жигунов А.В. Теория и практика выращивания посадочного материала с закрытой корневой системой. С.-Петер-бург: СПбНИИЛХ, 2000. 293 с.
7. Маркова И.А. Современные проблемы лесовыращивания. С.-Петербург. СПбГЛТА, 2008. 156 с.
8. Лесные культуры. Ускоренное выращивание / Е.М. Романов, Н.В. Еремин, Д.И. Мухортов [и др.]. Йошкар-Ола: МарГТУ, 2001. 156 с.
9. Сухов И.В., Кострыкин В.А., Казаков В.И. Технологии лесокультурных работ на вырубках. М., 2004. 150 с.
UDC 630.367
MACHINES FOR STUMPS EXTRACTION
post-graduate student of Forestry mechanization Department E. V. Pozdnyakov FSBEI HPE «Voronezh State Academy of Forestry and Technologies»
The working conditions of tractors and other forestry machinery, when planting forestry crops on the cutting plots, are much worse in comparison with those on the treeless areas, due to the presence of stumps, root systems and cutting remains. Moreover, in many regions it is necessary to process the soil as well as to fight against the fast-growing, uncontrolled vegetation for 10...20 years to make the culture growing successful. Therefore the technology of forestry crops
creation on the cutting plots should guarantee possibility of machinery application for the total vegetation period.
Creation of highly productive plantations on the cutting plots includes several basic technological operations common to different working conditions. The foresters combine these preparations into one group, defining them as preparatory activities on the cutting plot, stumps and trees extraction being the most labor-consuming among them [1].
Stump extraction can be carried out in four ways:
- by various machines, tools and devices;
- by means of explosion;
- with the help of fire;
- by destroying the stumps chemically, or infecting them by fungi cultures, provoking the wood decomposition.
These methods differ in their efficiency, and what is more important, they differently affect the state and structure of cutting plot ploughed horizon.
Thus, the stumps in the process of explosion are often split into parts, with their further ejection on the surface, while large roots remaining in the stump holes alongside with explosion craters block the village.
Stumps burning, chemical and biological methods have not become very popular in Russia [2].
At present mechanical method of stumps extraction remains the most widely used in forest planting. It is realized in the operations of rooting out, stump-decreasing and stump-eradicating [3].
Single-turn puller £-513A (fig. 1) with hydraulic control, installed on the tractor T-130, is one of the most popular pullers applied in home forest planting. These pullers are intended for rooting out forest vegetation and stumps, as well as rocks extraction from the soil up to 0,8 m deep and their further transportation outside the developed plot limits (40 m). The puller consists of multipurpose frame 2 and an earthboard 1 with four teeth 6. The earthboard, in its turn, has a view of box-section bridle 5 with the welded shoes intended for teeth assembling. The teeth are wedged in the shoes. Three bars covered by metal sheets 4 are welded over the bridle.
Radius seat for earthboard assembling on the ball head of multipurpose frame is welded in the earthboard bridle. Two cylinders 3 of hydraulic system assigned for lifting and lowering of working organ are mounted on the special perches. Maximum diameter of outrooted stumps is 45 cm. Puller efficiency is 0,11.. .0,17 hectare per hour.
The work of puller fl,-513A looks as follows: having approached a stump at the distance of 1.1,5 m, tractor operator lowers down the working organ by means of hydraulics and the extraction teeth deepen under the stump. The stump is extracted from the earth by the hydraulically lifted working organ in the moment of tractor's forwarding ahead. In
this moment the efforts from the stump extraction are passed to the tractor. Tractor running mechanism can spin during the stump extraction, tractors forepart bending ahead [4].
The lever pullers working limitation is in their necessity to stop at every stump, thus declining the total aggregate efficiency. Moreover to remove big stumps, the puller must approach the stump several times from different sides. This manipulation also negatively affects the aggregate efficiency and increases fuel consumption [2].
It's also important that all pullers form big craters and mix soil horizons, making the process of stump holes filling as well as off-soil stumps clearing very labor-consuming [1].
Machines of cutting-out type lack these limitations.
Cutter-out ^Kn-0,6 (fig. 2) with active tubular working organs is the most popular among cutting-out equipment. Application of active cutting working organs in the equipment of cutting-out type allows to cut-out stumps of any diameter by comparatively small efforts, making possible designing of less bulky and more maneuvering machines.
Fig. 2. Cutter-out ЯКП-0,6
Besides, sometimes the soil contains hard particles, and when the cutting tooth collides with them, it displaces these particles or gradually destroys them without working organ crash [2].
Cutter-out XKn-0,6 installed on the tractor T-150K is operated in the following way. The mill is positioned over the stump, then it is spinned up and lowered down by means of hydrocylinder. The cutting part of the mill cuts peripheral roots, spinning and deeping into the soil, then having cut in it with its grapples, it twists out the head root. Then the mill with the stump inside is extracted from soil with the help of hydrocy-linder. Nevertheless, this machine cannot work with different stumps diameters as well as with the stumps of sprouts type. Besides, the quality of its work depends on the physical and mechanical properties of soil [3].
A lot of existing cutters-out are unable to cut lower (vertical) roots, therefore after completing the stump extraction, it is necessary to apply additional equipment [2].
Stump-eradicators are the most efficient and ecologically friendly machines for stumps extraction, MYn-4 being the most well-known among them.
Eradicator MYn-4 (fig. 3) is intended for extraction of both stump overground part and trees of different species and dimensions by means of milling cut in the process of cutting plot preparation for the further forest planting or roads and cable constructions. This machine can be applied on the cutting plots cleared of the cutting remains and down timber.
Machine consists of frame mounted ahead of tractor T^T-55A, hinge boom 6,
1 2
Fig. 3. Stump-eradicator МУП-4
rotary working organ 1 with inclined turning axle, hydraulic cylinders 8, for moving the boom in vertical and horizontal planes, the train activating transfer box 3, the crankshaft 4, chained and hinged transmissions 5, center shaft 7 and reduction unit 2.
When this machine is used in the forest reconstruction works, stumpage overground part is extracted on the width of 2,4.4 m, depending on the applied technology.
In the process of work the aggregate is moving along the chosen route, stopping in front of the stumps on the distance equal to the boom reach. Then the tractor operator activates the drive of the working organ and brings the spinning mill (730 rpm) by means of hydraulic cylinder to side part of the stump about 5 cm above the ground surface, accomplishing its milling cut.
The splitters produce the cross-fibers cutting, contacting with the stump, while the second group of knives, in their turn, fulfills the parallel-to-grain shearing. Depending on the stump diameter and its condition, the tractor operator regulates the mill drive speed by a handle. Having fulfilled the milling cut, the boom with installed mill is lifted into the upper position by means of hydraulic system, then the aggregate proceeds to the following
stump.
The stump milling cut is fulfilled when the tractor stops. In this moment only a spinning mill is contacting with the stump. The stumps more than 40 cm high are mill cut in two stages, the machine efficiency being 80.100 stumps per hour [5].
Eradicator MYn-4 like other stump eradicators can level stumps only up to the level of ground surface, which is not enough for the adequate cutting plot preparation. The residuary stumpage underground part blocks up the efficient work of the ploughs, cultivators, disks and other tillage equipment. The tree-planting machines are in the worst situations because of the deeping (25.30 cm) of its shares. In the result the equipment experiences extra-loads. Therefore to counterbalance them, it is necessary to increase the mass of these machines as well as to use high-duty expensive materials. Moreover, the presence of underground stumpage part lowers the quality of forest cultural works.
Intensive cutting tools wear-out reduces the interval of cutting part sharpening and negatively affects the stump eradicators efficiency. It remains the main factor blocking the stump mill cutting below the ground surface.
Accordingly, to decrease the cutting tooth wear-out it is necessary to remove the upper soil layer around the stump.
References bibliographic
1. Сухов И.В. Подготовительные работы и обработка почвы под лесные культуры на вырубках: тексты лекций. Воронеж: ВГЛТА, 1998. 80 с.
2. Конструкции и параметры машин для расчистки лесных площадей / И.М. Бартенев, М.В. Драпалюк, П.И. Попиков [и др.]: монография. М.: Флинта: Наука, 2007. 208 с.
3. Беликов Е.В. Обоснование параметров фрезы с гидроприводом для понижения пней твердолиственных пород на лесных участках: дисс. ... канд. техн. наук. Воронеж: ВГЛТА, 2010. 171 с.
4. Свиридов Л.Т., Вершинин В.И. Технологии, машины и оборудование в лесном хозяйстве: учеб. пособие. Воронеж: ВГЛТА, 2002. 312 с.
5. Пошарников Ф.В. Технология и машины лесовосстановительных работ. Машины для расчистки лесных площадей: метод. указания к выполнению лаб. работ. Воронеж: ГОУ ВПО «ВГЛТА», 2007. 40 с.
УДК [630*:65.011.54]:621.825
НАДЕЖНОСТЬ РАБОТЫ ПРЕДОХРАНИТЕЛЕЙ РАБОЧИХ ОРГАНОВ ФРЕЗЕРНОЙ ЛЕСОХОЗЯЙСТВЕННОЙ МАШИНЫ С УПРУГИМИ НАЖИМНЫМИ
ЭЛЕМЕНТАМИ
кандидат технических наук, доцент, доцент кафедры деталей машин и инженерной графики
П. Н. Щеблыкин
кандидат технических наук, ассистент кафедры деталей машин и инженерной графики
Г. Н. Вахнина
кандидат технических наук, доцент, доцент кафедры деталей машин и инженерной графики
Р. Г. Боровиков
ФГБОУ ВПО «Воронежская государственная лесотехническая академия» [email protected], [email protected], [email protected]
О надежности фрикционных предохранителей судят по ресурсным испытаниям. Ресурс считается положительным, если число срабатываний было 5000 раз, а изменение момента срабатывания и износ фрикционного элемента при этом не превысили 10 % от первоначальных значений [1].
Ресурсные испытания предохранительных устройств характеризуются чис-
лом срабатывания. Их следует проводить до предельного состояния при установленном значении момента срабатывания. Предельное состояние предохранителей характеризуется:
- уменьшением момента срабатывания вследствие изнашивания элементов муфты в процессе испытаний;
- появлением значительных динами-
