RU2019939C1 - Working tool of soil-tilling machine - Google Patents

Abstract

FIELD: rototilling of soil. SUBSTANCE: working tool comprises cutter holder rotating around vertical axis, and cutter. Cutting edge of cutter extends along a helical curve disposed on cylindrical surface with a constant helix angle and its front lower curved end is directed forward along rotor rotation ω while cutter back side is turned relative to the perpendicular towards rotation radius to center through an angle exceeding 15 deg but smaller than 45 deg. EFFECT: reduced soil cutting force. 9 dwg

Description

 The invention relates to the field of agricultural engineering, in particular to tillage machines having a forced drive of working bodies rotating around a vertical axis.

 Known tillage machine with rotors rotating around a vertical axis. It consists of a gear-frame, inside of which a block of drive gears is installed. On their vertical axes, horizontal knife holders are mounted, at the edges of which vertical knives are mounted.

 The disadvantage of this machine is its high energy intensity due to a direct frontal impact with the front edge of the knives when they are working on the soil.

 The aim of the invention is to reduce the cutting force of the soil by making a knife with a curved front (lower) end forward along the direction of travel.

This goal is achieved by the fact that on the rotor of a tillage machine with a forced drive of the working bodies around a vertical axis, consisting of a knife holder and a knife in the form of a plate with front sharpening, the cutting edge of the knife is made according to a helical curve with a constant angle of elevation located on the cylindrical surface and the front lower the curved end is directed forward in the direction of rotation of the rotor, and the occipital (outer) edge of the knife is rotated relative to the perpendicular to the radius of rotation to the center by an angle of 15 ^about <φ <45 ^about .

A comparable analysis with the prototype allows us to conclude that the constructively proposed technical solution is new: the cutting edge of the knife is made according to a helical curve with a constant angle of elevation located on a cylindrical surface and the front lower curved end is directed forward in the direction of rotation of the rotor, and the occipital (outer) edge of the knife rotated relative to the perpendicular to the radius of rotation to the center at an angle of 15 ^about <φ <45 ^about . This new difference is significant, since it helps to reduce the efforts of cutting the soil, which is impossible to achieve in the work of its analogues.

 The search for analogues of devices in which vertical knives are made with the front lower end forward along the movement along a cylindrical surface did not reveal them. Thus, the claimed technical solution meets the criterion of "novelty" and the conclusion that the proposed solution meets the criterion of "significant differences" is reliable.

 In FIG. 1 shows a general view of a tillage machine; in FIG. 2-5 - rotor of a tillage machine; in FIG. 6 is a rotor diagram in axonometric projection; in FIG. 7 is a diagram of the operation of the cutting edge of a knife of a tillage machine; in FIG. 8 is a diagram for determining zones of mashing with the outer edge of a knife about an untreated monolith of a soil layer; in FIG. 9 is a diagram for determining the maximum angle between the absolute and peripheral speeds of a vertical knife when cutting off the formation from a soil monolith.

 The tillage machine (Fig. 1) contains an attachment 1, an upper gearbox 2, a main gearbox 3, through which drive shafts 5 are driven through a block of gears horizontally mounted in it 4. The drive shafts 5 are mounted on the shafts 5. vertical knives 7.

The aggregation of the tillage machine with the tractor is carried out using the attachment 1. The tractor power is transmitted through the power take-off shaft (PTO) to the upper gearbox 2 of the machine through a cardan drive (Fig. 1). Further, through a conical pair of the upper gearbox 2, the rotation is transmitted to the block of horizontally mounted and constantly engaged gears 4 of the main gearbox 3. Each of these gears 4 rotates the vertical drive shafts 5, at the ends of which the knife holders are horizontally mounted 6. At the ends of the knife holders 6 installed vertical knives 7. The rotation of the rotor (knife holder 6 and knife 7) on the tillage machine (Fig. 2, 3, 4, 5, 6) occurs around the vertical axis O-O. The designations in the figures are as follows: V — translational speed of the machine; ω is the angular velocity of rotation of the rotor; γ is the angle of elevation of the generatrix of the cutting edge of the knife; β is the angle (dull) cutting off the soil shavings from the monolith; N - height (vertical) of the cutting edge of the knife. The knife 7 is made in such a way that its cutting edge is made according to a helical curve with a constant angle of elevation located on a cylindrical surface and the front lower curved end is directed forward in the direction of rotation of the rotor, and the occipital (outer) face of the knife is turned relative to the perpendicular to the radius of rotation to the center at an angle of 15 ^about <φ <45 ^about .

The operation of the proposed knife on a tillage machine is shown schematically in FIG. 7 and 8 and occurs as follows. In the initial position (Fig. 7), the cutting edge of the knife occupies the position 1-1 _in ^I (a). In a plane parallel to the direction of translational motion (perpendicular to the field surface) and passing through the axis of rotation of the rotor - O (hereinafter referred to as the vertical plane), the cutting edge of the knife is only at its lower point - 1 ^II (s). Subsequently, when the knife’s cutting edge is rotated through an angle α / 4 where α is the angle of the knife’s solution, the plane angle (top view) between the radii drawn through the O-O axis of rotation, the upper (1) and lower (1 _g ^I ) points of the cutting the edge of the knife (Fig. 6 b), it is shifted in the direction of translational motion - V and occupies the position: 2 ^I -2d ^II - 2, that is, it is shifted in the direction of translational motion by a distance l ₁ = L / 4 where L is the total displacement in the direction of translational movement of the upper point of the cut soil chips with respect to the lower one and occupies the position 2 ^I -2 _in ^II - 2, with otorom the cutting edge of the knife passes through the specified vertical plane at point 2 _in ^II at a height h = H / 4 from the lower point of the cutting edge of the knife. The point of intersection of the vertical plane with the cutting edge of the knife will be T. 2 ^II (the procedure for determining this point is indicated in the figure by thin lines with arrows that go from points 2 _to ^II and 2 _g ^II ).

2;

3 и

4= α она аналогично изложенному будет смещаться в направлении поступательного движения на расстоянии 2l₁, 3l₁ и 4l₁=L (c), а режущая кромка ножа будет проходить через указанную плоскость в точках 3_в, 4_в и 5_в на высоте 2h, 3h и 4h=H (a). Точками пересечения интересующей плоскости (с) режущей кромкой ножа будут точки 3^II , 4^II и 5 (с аналогичным указанным построением).With further rotation of the cutting edge of the knife step by step at an angle

2;

3 and

4 = α, in the same way as described above, it will shift in the direction of translational movement at a distance of 2l ₁ , 3l ₁ and 4l ₁ = L (c), and the cutting edge of the knife will pass through the indicated plane at points 3 _in , 4 _in and 5 _in at a height of 2h , 3h and 4h = H (a). The intersection points of the plane of interest (c) with the cutting edge of the knife will be points 3 ^II , 4 ^II and 5 (with the same construction indicated).

Connecting the points (1 ^II - 2 ^II - 3 ^II - 4 ^II -5) between the passage of the cutting edge of the knife through the monolith of the formation, we determine the trajectory of movement (straight inclined line) of the considered cutting edge of the knife in the vertical plane of interest to us. The reservoir is then determined by the indicated inclined line 1 ^II -5 (s), i.e. it is not cut out, is not hollowed out of the monolith (as in the prototype), which is an energy-intensive process, but is cut off when the knife smoothly enters the monolith and the chip is inclined obliquely (with an obtuse angle β — the angle between the horizontal bottom line of the treated formation and the cut-off line from the monolith ) With this cutting off of the formation from the monolith, the cutting force, as is known, decreases by 20-25% (A.S. Buryakov et al. Shchelivanie soil inclined racks. M: Agriculture. 1987, N 2, p. 32-35).

 When the knife moves in the soil, the correct location of the occipital (outer) edge of the knife also matters. In FIG. Figure 8 shows that when the knife is located perpendicular to the radius of rotation (in the figure, the contours of the knife are represented by dashed lines) and when it moves along a complex path formed from simultaneous translational and rotational movements, the occipital edge of the knife is rubbed (crammed) into the untreated layer. This naturally dramatically increases the energy intensity of the tillage process. In order to prevent this from happening, it is necessary to turn the occipital face of the knife relative to the perpendicular to the radius of rotation to the center by a certain angle β.

, при направлении последней строго перпендикулярно направлению поступательной скорости - V_п. Поворот затылочной кромки ножа относительно перпендикуляра к радиусу вращения на угол

позволяет располагаться его наружной кромке параллельно направлению абсолютной скорости - V_a(т.е. практически параллельно траектории движения). Угол

равен
V_п=V_o ˙t_g

,

= arctg

При работе машин указанного типа, как известно, при малых поступательных скоростях (0,5-1,2 м/с) окружная скорость составляет 3-6 м/с, а при больших поступательных скоростях (1,2-2,5 м/с) окружная скорость находится в пределах 6-12 м/с. Отсюда искомый угол равен 6-23^о.As seen in FIG. 9, the angle φ between the direction of the absolute speed of the knife - V _a (which forms the path of the knife) and the direction of the peripheral speed - V _o has the maximum value

, when the direction of the latter is strictly perpendicular to the direction of translational speed - V _p . Rotation of the occipital edge of the knife relative to the perpendicular to the radius of rotation by an angle

allows its outer edge to be parallel to the direction of absolute speed - V _a (i.e., almost parallel to the trajectory of movement). Angle

is equal to
V _p = V _o ˙t _g

,

= arctg

When operating machines of this type, as you know, at low translational speeds (0.5-1.2 m / s), the peripheral speed is 3-6 m / s, and at high translational speeds (1.2-2.5 m / c) peripheral speed is in the range of 6-12 m / s. Hence, the desired angle is 6-23 ^about .

(чтобы не было частичного затирания задней частью наружной грани ножа о монолит почвы). Следовательно, для работы ножа без затирания о монолит почвы (без непроизводительных затрат) его затылочная (наружная) грань должна быть повернута относительно перпендикуляра к радиусу вращения до центра на угол 15^о< φ <45^о.Given that the path of the knife (cutting edge) along the entire length relative to the center of rotation is a concave line with varying curvature (Fig. 8), then the angle φ should be 10-20 ^about more than the angle

(so that there is no partial rubbing with the back of the outer edge of the knife on the monolith of soil). Therefore, for the knife to work without rubbing against the soil monolith (without unproductive costs), its occipital (outer) face must be rotated relative to the perpendicular to the radius of rotation to the center by an angle of 15 ^about <φ <45 ^about .

For a tillage machine with forced drive of working bodies around a vertical axis when working on medium-mechanical soils and a processing depth of 10-15 cm, the main parameters of the knife (Fig. 4 is an enlarged view of the knife in the knife holder in Fig. 3) will be as follows: knife width B = 40-70 mm, the thickness of the knife b = 15-25 mm and the angle of sharpening of the knife blade ε = 25-50 ^about .

 The application of the proposed constructive solution in a tillage machine will significantly reduce the energy consumption of tillage in comparison with the prototype. Along with this, this shape of the knife will contribute to the self-cleaning of the working body, which is made possible by lifting weeds located on the cutting edge of the knife from the lower layers to the upper. With constant weeding of these weeds with an oncoming processed layer, they (weeds) will rise along the indicated cutting edge of the knife (made along a helical curve with a constant angle of elevation and located on a cylindrical surface) from the lower layers to the upper ones, which will lead to self-cleaning of the working part of the knife, to weed removal of the entire working body. All this (reducing the efforts of cutting the soil, improving the self-cleaning of the working body) will allow 15-20% to increase labor productivity, reduce fuel consumption.

Claims (1)

A WORKING BODY OF A SOIL PROCESSING MACHINE having a forced drive to rotate around a vertical axis and comprising a knife holder and a knife in the form of a top-down plate with a front cutting edge, characterized in that the cutting edge of the knife is directed along a helical line having a constant elevation angle located on a cylindrical surface, the lower end of the specified cutting edge is shifted forward relative to its upper end in the direction of rotation of the working body, and the rear corner of the knife cutting has a value of Shua 15 ^o, but less than 45 ^o.

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