RU151655U1 - SPHERICAL SOIL PROCESSING DISC - Google Patents

Abstract

1. A spherical disk of a tillage implement having a cutting edge, slots and holes in the central part for mounting and fixing a bearing housing or an axis, characterized in that the slots are located on the disk within a circular ring, the outer diameter of which is the minimum diameter of the disk at which the permissible height of the ridges at the bottom of the furrow is maintained, and with an inner diameter equal to the diameter of the housing of the bearing assembly. 2. The disk according to claim 1, characterized in that the slots in the circular ring are made with the maximum possible total area, while maintaining the minimum required disk strength.

Description

The field of technology.

The proposed utility model is intended for use in tillage implements, where the working body is a spherical disk.

Prior art;

A disk is known (see German patent DE-OS No. 2828203) [1], containing a drop-shaped perforation located in a circle around the disk close to its perimeter and the base of the droplet turned to the edge of the disk. Such a disk should be buried more easily, but the resistance to sliding friction on the rest of the inner surface of the disk remains invariably large. There are no specific location coordinates and area of drop-shaped perforations.

The disk is spherical soil-cultivating (see patent on PM RU 78621 U1 MPK A01B 7/00 (2006.01)) [2], characterized in that the cuts in the disk sphere are made radially or at an angle to the radius of the disk, with the total disk area being 10- 30% of the disk area, the gaps between the disks form a system of spokes, the width of which is 0.7-1.5 of the average value of the width of the slot. Here, too, the main attention is paid to the total area of the slots with respect to the total area of the disk and the width of the gaps between the slots, i.e. knitting in relation to the average value of the width of the slot. However, it is impossible to make such a disk, since it does not contain a specific area for placing slots on the disk. Similar disadvantages are inherent in disk tools for disk harrows and other patents: US patent No. 4099576 [3], patent for the invention RU 2438282 [4].

Known disk spherical tillage tools (see patent for invention RU 2381639 C1 IPC A01B 15/16, A01B 23/06 (2006.01)) [5], selected as a prototype, where the spherical disk has slots and openings in the Central part for installation and mounting the bearing housing or axis, characterized in that the slots are made in the form of a curved quadrangle with radial sides made along a curve, for example, of a parabolic shape, and the curved radial sides with the convex side oriented in the direction of rotation of the disk. The disadvantage of such a disk is the lack of justification of the placement area and the area of the slots.

The technical result of the proposed utility model is the development of a disk with reasonable areas of placement and the total area of the slots, providing lower traction resistance and quality of soil cultivation - completeness of cutting the soil and destruction of weeds over the entire width of the soil till complete wear of the disk and increased passability of the disk implements when processing wet and waterlogged soils.

The above technical result is achieved by the fact that the slots of the disk are located in a strictly justified area, taking into account the wear of the disk during its operation, and the maximum permissible total area of the slots, at which the required disk strength is maintained, provides a higher throughput of the disk implements when processing wet and waterlogged soils without sticking and lower traction resistance.

Disclosure of a utility model.

The technical result is achieved by the fact that in the disk of a spherical tillage implement having a cutting edge, slots and holes in the central part for mounting and fixing the bearing housing or axis, according to a useful model, the slots are located on the disk within a circular ring whose outer diameter is the minimum diameter of the disk , at which the permissible height of the ridges at the bottom of the furrow is still preserved, and with an inner diameter equal to the diameter of the housing of the bearing assembly.

In this case, the slots in the circular ring are made with the maximum possible total area, while maintaining the minimum required disk strength.

A brief description of the drawings.

FIG. 1 is a diagram of stresses arising under the condition when soil is sliding along the material of the disk (steel) without sticking.

FIG. 2 is a diagram of stresses arising under the condition when soil sliding along the disk (steel) material is not observed.

FIG. 3a, 3b are diagrams of fragments of a spherical disk.

FIG. 4 is a diagram of slot distribution parameters.

FIG. 5 is a diagram of a spherical disk of a tillage implement.

Implementation of a utility model.

In more detail, the essence of the utility model can be explained as follows.

When treating the soil with disk harrows and cultivators, boundary surfaces arise between the soil and the internal sphere of the working bodies, and more specifically, between the soil and steel, and also between adjacent soil bodies - between a thin layer of soil adhering to the working body and a layer of soil moving along the inner sphere of the disk (Fig. 1 and 2). In the general case, with such relative displacements, stresses arise that act across the interface between two bodies, the soil layer, on the material of the inner sphere of the disk, i.e. o steel and a layer of soil about soil adhering to the surface of the inner sphere of the disk. The normal component of this stress causes sliding friction forces, the tangential component of which is the shear stress due to friction (A. Kulen, X. Kuipers, Modern Agricultural Mechanics. M., Agropromizdat, 1986, pp. 132-133).

According to the conclusion of A. Kulen and H. Kuipers, the dependence of soil and material characteristics from the conditions of soil sticking to the disk can be expressed by expressing the normal component a _{p of the} total stress R.

where a is adhesion;

c is cohesion;

φ is the angle of internal friction;

- оэффициент трения почвы о материал диска (сталь). Следовательно продвижению почвы без налипания будет способствовать возрастание σ_n. Поэтому в этой связи целесообразно применение дисков с прорезями, которые увеличивают σ_n, так как

, где S - общая площадь контакта почвы с поверхностью внутренней сферы диска, P_n - нормальная составляющая общего напряжения P.

- coefficient of soil friction on the disk material (steel). Therefore, the advancement of soil without sticking will be promoted by an increase in σ _n . Therefore, in this regard, it is advisable to use discs with slots that increase σ _n , since

where S is the total area of contact of the soil with the surface of the inner sphere of the disk, P _n is the normal component of the total stress P.

Friction of the soil when it glides along the working surface and adhesion are different phenomena, but they occur simultaneously. We note in this case that if the resistance to sliding friction does not depend on the area of their contact with each other i.e. F = fN, then the slip resistance from adhesion depends on the area of their contact S. The total slip resistance T caused by them is characterized by the following equation (see N.I. Klenin, V.A. Sakun. Agricultural and reclamation machines. M., Kolos, 1994, p. 17-19).

where F is the resistance of the soil to slip on steel (on the surface of the inner sphere of the disk);

T _np is the resistance to sliding of the attachment;

p _o - coefficient of tangential forces of specific adhesion in the absence of normal pressure;

f is the coefficient of sliding friction;

S is the area of contact of the soil with the surface of the inner sphere of the disk;

p is the coefficient of tangential forces of specific adhesion caused by normal pressure.

An analysis of expression (2) also shows that the total resistance T can be reduced by reducing the area of possible adhesion. Therefore, from the point of view of reducing traction resistance, it is necessary to increase the area of the slots of the surface of the spherical disk, and at the same time, the limit of increasing the cut-out area can only be the preservation of the required disk strength.

The disk of a tillage implement wears out during operation and its diameter decreases. It is also known that the radius of the disk R _{dmin is} less than which it is impossible to provide the required height of the ridges at the bottom of the furrow h _n when processing adjacent soil strips with disks located in the transverse direction in one of the different rows at a distance b and known angles of attack α and inclination angle β are determined by the expression (FN Kanarev. Rotary tillage machines and implements. M., Engineering, 1983, p. 87.) (Fig. 3a, 3b):

Example. With values: b = 80 mm, h _n = 40 mm, α = 18 °, β = 10 °, we obtain R _dmin = 226.5 mm or the diameter of the disk D _dmin = 453 mm.

If disks with a diameter of D = 560 mm are installed on a disk harrow, then after wear to a diameter of D = 453 mm, they cannot be used further, since the combing at the bottom of the furrow h _n will already begin to go beyond the permissible value h _n = 40 mm and even further whole unprocessed stripes will appear. Therefore, the permissible disk diameter D _dmin is the first limitation.

The second limitation is caused only by design features. This is the diameter of the housing D _{to the} bearing assembly, to which the disk is mounted and covers part of its area.

Thus, the slots can only be located within the circular ring (M.Ya. Vygodsky. Handbook of elementary mathematics. M., Nauka, 1975, p. 297) with a center coinciding with the center of the disk, with an external diameter D _dmin defined by the initial requirements for the combing of the bottom of the furrow h _n and the inner diameter And _to equal to the diameter of the bearing assembly to which the disk is attached (Fig. 4).

The second important parameter of the proposed spherical disk of the tillage implement, as shown in the description, are directly cuts. The very statement that the larger the total area of all the slots, the less will be the adhesion of the soil and traction resistance - this is already a parameter. But since it is impossible to completely cut out the circular ring, the statement of the imposition of the condition for ensuring sufficient strength in the area of the slots is an additional parameter for limiting the area of all slots.

None of the listed patents identified from the prior art have sufficiently clear definitions and starting recommendations for the location of the slots. This can lead to insufficient use of the efficiency potential of the working body with excessive removal of the beginning of the slots from the blade of the disk due to a decrease in the total area of the slots or to a decrease in the allowable wear of the disk if the slots start to be made in the disk closer to the blade of the disk than D _dmin . With regard to increasing the degree of crumbling of the soil with discs with slots, such results are not recorded in the literature and the authors themselves do not provide any evidence on this subject. Our long-term observations show that sticking to the surface of the disc is not observed at the depth of cultivation. At this depth, the inner surface of the disc is always clean, the paint has been erased and the surface of the disc even shines. This is explained by the fact that at the depth of processing of still intact dense soil, normal pressure on the surface of the disk is increased, which leads to an increase in resistance to sliding friction and, therefore, to the cleansing of adhering soil. With further advancement of the cut soil layer along the surface of the disk, the soil gradually loosens, its normal pressure decreases, and the friction of soil sliding on steel also decreases to a value that is not able to clean off the adhering soil. Therefore, on the disk, the volume of adhering soil to the center grows. This indicates the need to reduce the area of contact of the soil with the inner surface of the disk, primarily not in the depth zone, but with the rest of the inner sphere of the disk.

The disk works as follows. With the progressive movement of the disk harrow, disk working bodies are buried in the soil. At the same time, disks installed at an angle of attack shift a dense layer of soil at the same time perceiving pressure on the surface of the inner sphere of the disk at the site of penetration. With a sufficient amount of normal soil pressure at the depth of its processing, only resistance to sliding friction of the soil appears, while the adhering soil is cleared off with an increased value of sliding friction. Moreover, the value of this force fN is greater than the friction force of the soil layer on adhering soil p _o S + pNS, when it becomes necessary to overcome the internal bonds of the soil. With further advancement of the formation due to a decrease in the total area of the support of the formation by the size of the area of the slots, the specific normal pressure on the inner surface increases, which eliminates the buildup of soil on the rest of the disk. This indicates the need to maximize the area of the slots while maintaining the required strength of the disk.

On the figure. 5 is a schematic drawing of a spherical disk of a tillage implement. The disk has a mounting hole 1 and mounting holes 2 for mounting the bearing housing. The disk is equipped with slots 3 located on a circular ring with an outer diameter of D _dmin - the diameter of the disk, less than which the traction resistance increases, the height of the bottom of the furrow is violated; D _d - the diameter of the disk; D _to - the diameter of the housing of the bearing unit, providing cleaning of the disk from soil adhering to the disk and maintaining the required strength.

The location of the disk slots on the circular ring with the recommended parameters of the external and internal diameters will reduce the traction resistance of the disk and increase the permeability of the disk implements when processing wet and waterlogged soils, reduce traction resistance, and stable cutting of soil and weeds over the entire width of the soil treatment, i.e. will ensure the achievement of the technical result.

The invention is industrially applicable and can be manufactured in the factory.

INFORMATION SOURCES.

1. German patent DE-OS No. 2828203.

2. Patent for PM RU No. 78621. DISC SPHERICAL SOIL PROCESSING TOOLS. Published on December 10th, 2008.

3. US patent No. 4099576.

4. Patent for invention RU 2438282 WORKING BODY OF DISK WEAPONS. Published on January 10th, 2012.

5. Patent for invention RU 2381639 DISK SPHERICAL SOIL PROCESSING TOOLS. Published 02/20/2010 - the closest analogue.

Claims (2)

1. A spherical disk of a tillage implement having a cutting edge, slots and holes in the central part for mounting and fixing a bearing housing or an axis, characterized in that the slots are located on the disk within a circular ring, the outer diameter of which is the minimum diameter of the disk at which the permissible height of the ridges at the bottom of the furrow is maintained, and an inner diameter equal to the diameter of the housing of the bearing assembly. 2. The disk according to claim 1, characterized in that the slots in the circular ring are made with the maximum possible total area, while maintaining the minimum required disk strength.

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