Grab Excavator - Drawings

Introduction

Excavators are excavators designed for digging and moving soil. All excavators, depending on the use of working time for digging soil into two groups: continuous - multi-oar and periodic - single-bucket. Single bucket excavators are more common due to their versatility. Hydraulic excavators have structural, technological and economic advantages over a mechanically driven excavator. The design of the excavator with hydraulic drive, unlike cable machines, allows not only to increase the productivity of excavators of similar sizes, but also to a significant extent to mechanize the performance of the above-mentioned earthworks. The latter relates in particular to excavators-planners with telescopic working equipment and excavators with a tracking control system.

Hydraulic mounted excavators began to be produced in the United States in the late 40s, and then in England. In Germany, hydraulic drive was used in the 1950s for both hinged and full-turn excavators.

The number of different types of replaceable working equipment and working tools (buckets of different shape and purpose) of hydraulic excavators is constantly increasing. This makes it possible to expand the field of application of excavators and, using specific qualities of machines with hydraulic drive and their working equipment, to mechanize the performance of a number of works in construction .

The grapher is designed for the development of soils located both below and above the excavator parking level, for loading and unloading loose materials and crushed rocks, as well as for digging deep wells and pits, cleaning ponds and channels.

On excavators with hydraulic drive rigidly suspended grabbers are installed, which are fixed on handles of reverse shovel instead of ladle. The main advantage of a rigidly suspended grab over a rope is that they can create the necessary pressure on the ground during a crash, that is, regardless of the mass of the grab, they can successfully develop dense soils.

Chapter 1 Overview of literary and patent sources on the subject of the diploma project.

The main parts of the construction excavators are a caterpillar or pneumatic wheeled running device, a rotary platform (with a power plant, mechanisms, a control system and a driver's cab located on it) and replaceable working equipment. Rotary platform rests on running device through unified roller support-turning circle and can rotate relative to it in horizontal plane.

The working cycle of a single bucket excavator during soil development consists of the following sequential operations: digging soil (filling the bucket with soil), lifting the bucket with soil from the bottomhole, turning the bucket to the point of unloading, unloading soil from the bucket to the dump or to vehicles, turning the empty bucket to the bottomhole and lowering it to the initial position for the next digging operation. During operation, individual cycle operations can be combined (for example, lifting or lowering a bucket with turning it into a bottomhole), which allows you to reduce the duration of the cycle.

. Economic part

Introduction

Methodological guidelines on feasibility studies are devoted to the calculation of the economic part of diploma projects of students of the SDM specialty.

The guidelines include two sections with examples of calculations and the use of computer technologies. The first section presents the method of calculation of technical and economic parameters of manipulator operating equipment on the basis of a single-bucket excavator. In the second part the method of calculation of economic parameters of repair and operation base is given. The method of calculating the first section has versatility; to the extent that it is applicable for the feasibility of any mechanical systems: benches, hinged equipment, machines, devices, etc. According to the method of the second section, calculations, in addition to repair and operational bases, can be carried out for the maintenance station and factories for the overhaul of construction and road machines.

For this section of the diploma project, students perform one graphic sheet of the A1 format, in the second they give a table of calculated technical and economic indicators.

Purpose of work

Practical application of students' knowledge in the theoretical disciplines "Economics of SDM production" and "Informatics."

4.1 Feasibility Studies of New Equipment Using Single Bucket Excavator Manipulator

Manipulator on the basis of hydraulic excavator EO3323 includes two handles installed on the boom of the excavator and driven by hydraulic motors. Replaceable working equipment is installed on the flange of the handle of the working equipment; pneumatic hammer, cutter, glue grip, gripper. Currently, manipulators based on the EO3323 excavator with a turning drive, working elements and a handle using a hydraulic cylinder are used. The use of hydraulic cylinders for turning the working members limits the angle of their rotation, which narrows the application area and the working tool processing area from one position of the base machine. The use of hydraulic motors for these purposes allows increasing the performance of the manipulator. As the basic version (BT), we use a manipulator on the EO3323PEZ excavator.

Technical characteristics of basic equipment (WT)

1. Basic machine EO4321.

2. Engine power 80.W.

3.Hourly fuel consumption, kg/h 15.0.

4. Crankshaft nominal speed ,

rpm - 1700.

5.Nominal pressure of hydraulic system, MPa - 25.

6. Mass of the base machine, t - 9.

7. Mass of working equipment, kg - 128.

8. Operation cycle time, s - 76.

9. Wholesale price of working equipment, thousand, catfish - 26.25.

Technical characteristics of the designed manipulator (NT)

1. Base machine EO-4321

2. Engine power 80 kW

3.Hourly fuel consumption, kg/h 15.0.

4. Crankshaft nominal speed ,

vol ./min1 700.

5.Nominal pressure of hydraulic system, MPa - 25.

6. Mass of the base machine, t - 9.

7. Mass of working equipment, kg - 128.

8.Time of manipulator operation cycle from one unit

excavator, s - 45.

9. Number of maintenance personnel, people - 1.

4.2 Feasibility Studies

Capital expenditures for basic equipment are determined at a wholesale price of 30 = 25 thousand som:

3k = 3oKb = 25∙1,05 = 26.25 thousand soms,

where KB is the transportation and installation cost factor, KB 1.05.

4.3 Calculation of current annual costs

The current annual costs include the cost of electricity during the year, the cost of salaries of workers, the working fluid of the hydraulic system and gear oil, maintenance and maintenance, and overhaul.

Conclusion

During the work on the diploma project, issues related to the design of a new and improvement of existing equipment were studied, a number of sources with patent literature related to construction and road equipment were considered. Thus, all the work done can be presented in the following form:

• review of literature and patent sources;

• calculation of digging forces by the working body

• power drive calculation

• handle hydraulic cylinder

• calculation of the main parameters of the excavator.

• determination of single bucket excavator performance.

• excavator traction calculation

It was also necessary to draw out the general view of the grab excavator, the assembly drawing of the working equipment and the assembly drawing of the working tool.

During the diploma project, the following values ​ ​ of the designed excavator were obtained:

1. Required tractive force W = 44.4 kN;

2. Engine power N = 58 kW;

3. Capacity P = 21 m3/h.