Theoretical and experimental aspects of studying the disc working body of the feed chopper

The article discusses the issue of preparing stalk feed for feeding cattle in small-scale farming with an energy-saving technical means, a stalk chopper with a disk working body. A constructive-technological scheme of a disk working body of a grinder equipped with combined cutting segments is proposed. The main results of theoretical and experimental studies of the process of milling stem feed are presented.


Introduction
Agriculture is a large sector of the Russian economy, which needs to be developed through state support for personal subsidiary plots, small farms, and peasant farms. To solve this problem, it is necessary to provide the livestock sector with modern resource-saving technical means, especially in the conditions of small-scale farming, where the share of manual labor is especially high.
In the Krasnodar Territory, programs to support small businesses have been developed, grants and subsidies are allocated for the production of livestock products, the purchase of breeding animals and their raising.
Animal products, which are in great demand among most Russians, contain many micro and macro elements necessary for the human body. Meat, milk and eggs contain many vitamins that the body needs all year round. For example, vitamins of group B (B1, B5, B2, B6), PP, K, A, C, affect the functioning of the nervous, cardiovascular, endocrine and other systems [1].
The number of livestock of all cattle, all agricultural producers in farms by the end of September 528.4 thousand heads, including 209.9 thousand heads of cows. According to the survey, in the regions there are 626 thousand pigs, 220 thousand sheep and goats, and poultry about 26.7 million heads. The milk yield per cow in the months from January to September 2019 was 6,000 kg Milk, compared to last year, this figure increased by 2.7%.
Small business is a small enterprise of any form of ownership, characterized by a limited number of employees and occupying a small share in the overall activity, which is the basis for national or regional enterprises [1].
There are two main subjects of the IFC: • personal subsidiary farming is a form of non-entrepreneurial activity for the production and processing of agricultural products, carried out by the personal labor of a citizen and his family members; • peasant (farm) economy is an association of citizens who are related, have common ownership of property and jointly carry out production activities. The use of technical means for the preparation of feed in conditions with a high proportion of manual labor is associated with solving the problem of reducing labor and other costs of production.
When feeding animals, about 60% of the resources and time is spent on the preparation of feed [2], [3], [4], [5]. This process is the most time consuming and energy consuming, which also requires financial costs. When crushing feed, the machines use various working bodies in design, mainly knives that perform oblique and sliding cutting.
This working mechanism is less energy intensive than hammers and crushing. In order to minimize losses, it is necessary to use technical means in combination with various technical operations: loading feed, drying, grinding, mixing, etc.
Analysis of technical means according to literary sources showed the presence of such means. The main technical characteristics of such machines are performance and specific energy consumption. Table 1 shows the comparative characteristics of some feed grinders. Currently, a large number of studies have been carried out on the process of grinding stalk feed. But there is little research into the process of grinding stalk feed, proposed by a chopper with a disc working body, equipped with cutting segments of various types.

Materials and methods
In this work, the object of research is a stalk feed chopper, which has a disk working body. On the disk working body, there are different types of cutting segments that carry out sliding, oblique cutting. Since the solution to the issue of energy saving is relevant for the grinding process, the subject of research is IOP Conf. Series: Earth and Environmental Science 839 (2021) 042032 IOP Publishing doi:10.1088/1755-1315/839/4/042032 3 the dependence of specific energy consumption on the parameters of the grinder [1]: angular velocity of the grinding working body, the angle of inclination of the knives to the disk surface, and others. In the course of the research, tasks were set for the development of a structural and technological scheme of a stalk feed chopper, as well as theoretical and experimental studies to determine the productivity, specific energy consumption of the chopper, rational parameters of cutting segments. In theoretical studies, we used the mathematical apparatus of higher mathematics, theoretical mechanics, and experimental studies in accordance with existing methods and were based on planning a multifactor experiment.
A distinctive feature of the proposed technical means (figure 1) is a cone-type disk working body, equipped with combined cutting segments, which allows you to uniformly affect the material in longitudinal-transverse directions (multi-plane cutting); reduce the energy intensity of the process by cutting with sliding and transporting feed to feeders or bedding in stalls by air flow; improve the quality of grinding; increase operational reliability and service life. The working body of the chopper is coneshaped, on which the combined cutting segments are fixed. Rotating on a cone-shaped working disc, as the material is cut off, the lower part of the roll moves apart on a cone and multilevel cutting segments of various types 11, 12,13 cut the layers of feed in a spiral. The main factors on which the energy consumption of the feed grinding process depends are: type and moisture content of the material, cutting speed, sliding angle, type of cutting segment and its location, geometric parameters of the cutting segment, productivity and others. To highlight the significant factors, a one-factor screening experiment was carried out, which allows you to highlight the significantly influencing factors on the optimization of the grinding process (table  2). The value of the specific energy consumption of the process can be determined from the formula: . (1) Grinder capacity (t / h): For experimental studies, a laboratory sample of a stalk chopper was made. The diameter of the grinding bunker was 0.56 m, the diameter of the conical grinding working body was 0.45 m, the height of the bunker was 0.75 m, and the size of the grinding segments located along the perimeter of the grinding working body was 0.055 m. Bale size 50*50*70 cm with a weight of about 6 kg.
In the process of experimental research, it was necessary to establish the influence of "the designmode parameters of the grinder on the quality and energy indicators of the grinding process" [1].
The divergence of the results for the productivity and specific energy consumption of the grinder (figures 3, 4), obtained experimentally and theoretically, was determined according to Fisher's criterion and does not exceed 7%.
The models are adequate with a confidence level of 95%, and some of them with a confidence level of 90%. The correlation of the calculated values with the experimental data was higher than 0.9.