Development of impact-type ripper with bulldozer dump based on T-130

Contents

1. INTRODUCTION

2. RIPPERS, THEIR CLASSIFICATION,

PURPOSE AND SCOPE

3. PATENT SEARCH

4. BULLDOZER RIPPER BASED ON T-

5. SELECTION AND CALCULATION OF BASIC PARAMETERS

6. TRACTION CALCULATION

7. STRENGTH CALCULATION OF RIPPER TOOTH STRUT

8. CALCULATION OF RIPPER CAPACITY

9. SAFETY PRECAUTIONS

10. LIST OF LITERATURE

APPLICATIONS

Rippers, their classification, purpose and scope

Mechanical rippers are designed for layer-by-layer separation of rock into separate pieces or blocks of such dimensions as are necessary for subsequent effective development, transportation or loading. Tillers are also used to remove boulders, stumps, etc.

Application of loosening units on preparation of permafrost rocks for excavation makes it possible to increase efficiency of use of bulldozers, scrapers, loaders, excavators, reduce cost of development of frozen rocks, increase safety of works. The cost of work when loosening frozen rocks with hinged rippers is several times lower than in the drilling and blasting method.

There are a large number of rippers of various structures, which can be divided into the following types: by type of traction - into hinged and trailed; on loosening depth - on looseners of general (for surface loosening to a depth of 500 mm) and special purpose (for loosening to more than 500 mm); in terms of engine power of the base tractor - on low-power rippers (less than 100 hp), medium power (100200 hp), powerful (200400 hp) and super-powerful (over 400 hp); according to the type of running device of the base tractor (tractor) - on rippers on caterpillar and pneumatic wheeler.

In addition, for the intended purpose, rippers are divided into auxiliary and main. Auxiliary rippers are mounted in the unit with the main equipment - loaders, staplers, auto graders or hung on bulldozer dumps. When developing high-strength soils, forming slopes, trenches and pits, dumps with loosening teeth or special dumps with built-in teeth are used. Structures of tooth fastening elements on dump of conventional design allow adjustment of tooth pitch depending on the type of work and properties of material to be destroyed.

Recently, special dumps equipped with ripping teeth built directly into the dumps have received increasing recognition. During planning work, the teeth are removed. The greatest depth of tillage of the teeth is 305 mm and the tillage angle is 40 °. Two types of replaceable tips borrowed from the hinged rear ripper are provided. The installation of teeth at the corners of the dump facilitates the loosening of materials at the joints of the ledges and slopes, where it is difficult to use the rippers of the rear location. The hydraulic drive allows the driver to control the teeth remotely without leaving the cab.

In some cases, in order to increase the efficiency of bulldozing equipment, rear loosening teeth are installed on the dump, which allow the development of high-strength soil on the idling of the tractor when moving backwards.

General-purpose rippers are equipped with one foot, and a special one - with one or three detachable teeth of a straight or curved shape. Curved teeth are used when loosening rocks to a depth of up to 800 mm. They provide loosening with less effort due to their ease of deepening. However, when they are used for loosening frozen and rocky rocks, jamming of broken blocks between the tooth and the loosener frame occurs, which leads to a significant increase in the resistance of rocks to loosening. Straight teeth do not have these disadvantages, so they are more preferred for loosening frozen rocks to a depth of more than 800 mm. Teeth with a slight bending of the working part are also used, which are easily embedded in the rock at the beginning of deepening and are suitable for loosening various rocks, but their most effective use in the development of rocks of medium strength. For heavy work, hinged rippers of special structures are created. They are distinguished by increased strength, increased tooth length and usually work with push tractors.

The most loaded element of the ripper working element is the struts with tips (teeth). Posts are made forged or cast.

Their service life on average does not exceed 2000 h. The structure of the working element is selected taking into account the physical and mechanical properties of the soil, as well as the type of ripper. When developing high-strength soils, most often straight posts with a slight bend in the lower part are used

One of the main force elements of the tooth of the ripper is a tip directly acting on the soil and contributing to its destruction. Significant dynamic loads on the working body predetect the creation of high-strength and simultaneously resistant to abrasive wear tips. The high strength of the tips, the preservation of long-term operability and fast deepness depend on the correct choice of rational parameters of the shape, material and manufacturing technology.

In order to prevent wear of the front working face of the post, especially in its lower part in contact with the rock, the working elements of the rippers are equipped with steel protective linings and removable, usually forged or cast, less often welded tips made of especially wear-resistant magnesium manganese or manganese nickel steels .

For loosening of frozen rocks, narrow self-rolling tips with a bent end of the VNIIstroidormash structure are most suitable. The section of the bent part of the tip is trough-shaped, which reduces its contact area with the rock and creates a large specific pressure on the rock at the time of deepening. As a result, a tooth provided with such a tip is well embedded in the frozen rock .

Bimetallic tips or wear-resistant surfacing may be used to provide self-stability. Bimetallic tip is welded from two parts: crown and sock. Toe is cooked from bimetallic sheet obtained by friction welding. The upper, more brittle layer of 3540 mm thick steel with additives of manganese, chromium, molybdenum and niobium after hardening and tempering has a hardness of HRC 5758. The lower layer is more ductile, the hardness of its HRC 3241. The durability of such tips is 3 times higher than cast ones.

According to the design, the tips are divided into composite and solid. Components include a crown and a shoe. They are used to develop weak abrasive rocks. The durability of the shoe ensures the replacement of 1020 tips. Solid tips have high strength characteristics. They are used in the development of heavy rock and frozen rocks.

General requirements for the design of the tip: easy penetration into the rock, good resistance to impact and abrasion, the ability to self-roll and form cracks in the rock.

The service life of tips used on the loosening of frozen and abrasive rocks is 410 hours, during the development of rocks such as sandstones, tuff, brown coals - 30-50 hours, during the loosening of limestones, shale - 100-120 hours. During the wear of the tip, the amount of repulsive reaction from the rocks increases sharply, the productivity of the loosener decreases and significant vibration loads occur, transmitted to the base tractor.

In recent years, the practice of mechanical tillage has used extenders installed on working bodies, which make it possible to more efficiently develop, reduce the energy indicators of the tillage process and wear and tear of working bodies. In this case, a furrow with a width significantly exceeding the width of the cutting edge of the tip is formed in the rock mass, which allows almost completely destroying the soil between neighboring furrows.

As practice shows, the use of wideners allows loosening of rock by a width of up to 76112 cm, increasing the productivity of the loosener by 22.5 times. The wideners provide a more stable motion of the tractor, facilitate its control and simultaneously crush the rock well.

The control of the working element of modern rippers is performed only by a hydraulic drive, consisting of an oil tank with a filter, hydraulic pump, distributor, working cylinders, steel and flexible pipelines, check and safety valves and coupling couplings. Unified three-position or four-position hydraulic distributors are used to control the unit.