RU2309573C2 - Rotary working tool for mower - Google Patents

Abstract

FIELD: agricultural engineering, in particular, technique used in mowers for mowing of natural and sown grasses.

SUBSTANCE: rotary working tool has rotor with vertical axis of rotation and cutting member made in the form of flat circular disk having sharpened outer edge and axially aligned with rotor. Disk is fixed at rotor lower base. Rotor is formed as hollow truncated cone with circular flange at its lower base and slotted hub at its upper base. Rotor has two curved plates arranged in inclined position on rotor surface, at an acute angle relative to direction and plane of rotation.

EFFECT: reduced specific consumption of power for mowing process, minimized time for maintenance of mower cutting members, and improved shearing quality.

2 cl, 3 dwg

Description

The invention relates to agricultural machinery and can be used in rotary mowers used for mowing natural and seeded grasses.

Known non-supportive rotary-disk working bodies of mowers, including a vertical drive shaft and a disk with articulated knives (N.I. Klenin, V.A. Sakun. Agricultural and reclamation machines. M .: Kolos, 1994, p.335-336) .

Known rotary mower KPH-2.1 (Mower rotary KPH-2.1. Technical description and instruction manual (TO). Lyubertsy production association "Plant named after Ukhtomsky. - M., 1985), as well as a mower rotary mounted KRN - 2.1 A manufactured by JSC "Lyubertsy Agricultural Engineering Plant" (Mounted rotary mower KRN-2.1 A. Operating Instructions. M., 2001). The working body of this mower includes a disc mounted on a vertical shaft with two pivotally mounted blade knives.

Non-supportive cutting of stems is carried out by plate knives mounted on rotors in pairs rotating at a speed of 65 m / s, and the mowed grass is picked up by knives and carried out of the cutting zone.

The disadvantages of these working bodies are:

- very large specific energy costs (exceeding 15-20 times the energy consumption with manual mowing);

- excessive grinding of stems, leading to losses of up to 10% of the crop of mowed herbs;

- intensive and uneven along the length of the blunting and wear of the cutting edges of the knives, requiring frequent, after 2-4 hours of operation of the mower, sharpening or replacing the knives, due to the high load per unit length of the cutting edge of the skin, since mowing the grass with one rotor is carried out by knife blades with a total length of 10-12 cm with a working width of 50 cm, and uneven wear does not allow for self-sharpening;

- the removal of mowed grass by rotating in a horizontal plane rotors is not effective enough for dense and high grass, as a result of which the mowed mass is subjected to additional grinding, which leads to increased energy consumption and yield loss;

- a rotating working body with knives has increased danger and requires special safety measures: fencing the tractor cab, removing people to a distance of at least 50 m from the working mower, and when the cutting apparatus is tilted to a horizon of 7 °, not less than 90-100 m.

Also known is the rotary cutting apparatus closest in purpose to the claimed invention to ensure an optimal cutting process and reduce energy consumption (AS USSR No. 1644778 published April 30, 91, Bull. No. 16).

The working body includes a vertical shaft and flexible cutting elements-knives fixed on its lower end, rotating in the horizontal plane in the form of separate plates-segments of variable height with variable stiffness along the length. The value of rigidity and the regularity of its change is established from the conditions of observing the identity of the sliding cutting modes of the proposed working body and the manual braid.

The main disadvantage of this working body is the impossibility of reproducing the conditions of a sliding cutting with a manual oblique while rotating curved knives and translational movement of the rotor. Manual slanting cutting is characterized by the ratio between the tangential movement of the blade S _T (blade length) and its normal movement S _H equal to S _T / S _H = 6, as well as the ratio of the corresponding speeds V _T / V _H = 10. To fulfill the first condition (S _Т / S _Н = 6) as applied to a curvilinear blade rotating at a constant angular velocity with the simultaneous translational movement of its rotation center (mower motion), it is necessary that the front edge of the blade in contact with the grass move in a direction perpendicular to the translational motion direction (equivalent blade length) was six times the translational movement of the mower. This is possible for blade points with a radius of rotation R equal to the value of the translational movement of the mower, provided that their circumferential movement is equal to 6R, which is 0.955 of the circumference of a radius of R, i.e. almost corresponds to one revolution of each point of the blade. Obviously, for curved blades in the form of spirals, this condition is not feasible, since all of their points have different radii of rotation and, accordingly, different peripheral speeds, and the scan length of any spiral inscribed in a circle with a central angle between the smallest and largest radii of its points equal to 2π, significantly less than the circumference. The length of the spiral inscribed in a circle of radius R is equal to the largest radius of the spiral, will be equal to the length of this circle only if the central angle between its smallest and largest radii exceeds 2π, i.e. the end of the spiral should overlap its initial section, and for this section the contact of the cutting edge with the grass stand is impossible.

The condition for compliance with the second ratio (V _T / V _H = 10) is determined from the equality:

2πRω = 10R,

whence the required number of revolutions of the blade at a translational speed of V _N = 10R m / s should be:

ω = 10R / 2πR = 1.59.

Thus, if more than one knife is installed on the rotor, only their ends will participate in the cutting process, and the work of curved knives will be similar to the work of straight knives of known mowers with repeated cutting of stems, intensive wear of the ends of the knives and other disadvantages noted above. Another significant drawback of the considered working body is the extreme complexity of the design.

The objective of the invention is to reduce specific energy consumption for mowing, reducing crop losses and reducing the time spent on maintenance of cutting tools of mower elements, as well as ensuring a high-quality cut.

The solution to this problem is achieved by the fact that the proposed rotary working body of the mower, including the rotor, made in the form of a hollow truncated cone with an annular flange on the lower base, with a spline hub at the upper base and two inclined curved plates located on the rotor surface mounted at an acute angle relative to directions and planes of rotation, as well as a cutting element made in the form of a flat annular disk with a pointed outer edge mounted coaxially with the rotor m and mounted on its flange, according to the invention, when rotated in a horizontal plane with simultaneous translational motion, it provides an energy-optimal sliding cutting mode, constant contact of the cutting edge with the grass stand, eliminating re-cutting of the stems, as well as effective removal of the beveled mass from the cutting zone with raising it above the rotor by rotating inclined plates. Reducing the time spent on servicing and replacing cutting elements is achieved by reducing the wear rate of the blade during operation by increasing the ratio of the length of its cutting edge to the working width of the mowing grass stand to 3.5, which is 15 times more than that of the known KRN-2.1 mower , and also due to the fact that due to the uniform wear of the proposed cutting element, it can be self-sharpening and maintain the specified optimal sharpening angle during operation.

The invention is illustrated by drawings, where in Fig.1 shows a General view of the rotary working body of the mower, Fig.2 is a section, side view, Fig.3 is a top view.

The working body contains a rotor 1 in the form of a hollow cone with a flange 2 and a spline hub 3; a cutting element 4 in the form of a flat ring with a pointed outer edge, mounted on the rotor flange 2 with screws 5; two curvilinear plates 6 mounted on the surface of the rotor obliquely, at an acute angle with respect to the direction and plane of rotation of the rotor, while the outer edges of the plates have a variable radius, decreasing in the opposite direction from the initial ρ ₀ equal to:

ρ ₀ = R-Δ,

where R is the radius of the cutting edge of the blade;

Δ is the gap (distance from the cutting edge to the beginning of the insert 6), Δ≈40-60 mm;

to a finite ρ _k equal to

ρ _k = ρ ₀ -S _0.5 ,

where S _0,5 - the value of the translational movement of the rotor for 0.5 rotor rotation, determined depending on the adopted ratio V _T / V _N (at V _T / V _N = 10, S _0.5 = 0.31R).

The rotary working body of the mower operates as follows.

During rotation of the rotor mounted on the drive shaft and simultaneous translational movement of the mower, the cutting element performs non-supportive sliding cutting of the stems during continuous contact with the grass stand, and the inclined plates mounted on its surface rotate along with the rotor and capture the cut grass and remove it from the cutting zone, lifting it above the rotor.

This method of removing mowed grass has an obvious advantage over that used in conventional rotary mowers by spreading the grass with knives in a horizontal plane, because the grass is not subjected to repeated cutting and does not interfere with the movement of the mower.

Claims (2)

1. The rotary working body of the mower, containing a rotor with a vertical axis of rotation, a cutting element, characterized in that the cutting element is made in the form of a flat annular disk with a pointed outer edge mounted coaxially with the rotor and mounted on its lower base, and the rotor is made in the form a hollow truncated cone with an annular flange on the lower base and a spline hub at the upper base and has two curvilinear plates mounted on the surface of the rotor obliquely at an acute angle relative to board and plane of rotation. 2. The rotary working body of the mower according to claim 1, characterized in that the outer edges of the curved plates mounted on the rotor have a variable radius that is smaller than the radius of the cutting edge of the disk cutting element and decreasing in the opposite direction of rotation.

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