Bulldozer with a controlled middle knife

Contents

Introduction

1 Analysis of patent and scientific literature

1.1 Analysis of patent literature

1.2 Analysis of scientific literature

2 Justification of selected structure

2.1 Description of the selected structure

2.2 Advantage of development implementation

3 Calculation of basic parameters

3.1 Nominal pulling force, operating weight and main operating speeds of bulldozer

3.2 Substantiation of middle knife parameters

3.3 Length and height of dump

3.4 Traction calculation

3.5 Determination of forces in hydraulic cylinders

4 Strength calculation

4.1 Calculation of strength of slider displacement axis

4.2 Calculation of knife movement traction strength

5 Part Manufacturing Process

5.1 Part Assignment

5.1.1 Description of the structure and conditions of its operation in the mechanism

5.1.2 Part material, mechanical properties, type of heat treatment

5.2 Constructability Analysis

5.2.1 Selection of basing surfaces

5.2.2 Application of high-performance processing methods and reduction of labour input

5.2.3 Possibility to reduce metal consumption

5.3 Determination of part lot value

5.4 Selection of workpiece production method

5.5 Purpose of part manufacturing process route

5.6 Selection of equipment and accessories

5.7 Calculation of cutting modes

5.8 Calculation of time standards

6 Project safety and environmental friendliness

6.1 Prospects of BJD in the construction and road machinery and equipment industry

6.2 Analysis and identification of hazards during operation of bulldozer equipment

6.3 Development of technological and organizational solutions for elimination of identified hazards

6.4 Calculation of cabin heat balance

6.4.1 Calculation of cabin heat balance in summer period

6.4.2 Calculation of cabin heat balance in winter

6.5 Recommendations for safe operation of bulldozer equipment

6.6 Conclusion on the suitability of bulldozing equipment for use taking into account the requirements of BJD and ecology

7 Metrology and standardization

7.1 Main tasks of metrology

7.2 Main Standardization Tasks

7.3 Regulatory documents

8 Project Feasibility Study

8.1 Identification of design and operational advantages of new equipment and selection of basic equipment

8.2 Determination of annual operating capacity of equipment

8.3 Calculation of one-time capital costs

8.4 Determination of annual current consumer costs

8.5 Calculation of Economic Effect

List of sources used

Appendix A Specifications

Introduction

The development of new equipment and modernization becomes the main task set by operational organizations for machine-building enterprises.

To solve this problem, machines of increased unit power and productivity are developed and produced, and finally, machines that provide significant savings in fuel and other energy resources.

In order to increase the pace of work and set ourselves the task of using bulldozers of low capacity on soils of a high category, in order to increase the annual fund of work and thereby the annual productivity of both the machine itself and the fleet where this machine is operated.

Justification of selected design

2.1 Description of the selected structure

We take the design of the working equipment of the bulldozer with a controlled middle knife as the basic one (1) (Figure 2.1).

invention relates to bulldozer-type earth-moving transport machines whose dump tools are provided with cutting edge protruding in middle part.

Bulldozer working member consists of dump 1 with main knife 2 and casing 3. In the casing 3 there are vertical guides 4 parallel to the plane of the main knife 2. In the lower part of the dump, by means of vertical guides 4 of the casing 3, a middle retractable knife 6 is installed on the stiffening box 5. Horizontal guide 7, for example of tubular section, with stops 8, is installed on rear side of dump parallel to main knife. In horizontal guide 7 there installed is intermediate element made of horizontal rod 9, which slides along horizontal guide 7 by means of bushings 10.

The intermediate element is connected to the retractable knife 6 by means of inclined links 11, for example of rectangular cross-section, installed parallel to the plane of the main knife 2, hingedly connected on one side to the stiffness box 5 of the retractable knife 6, and on the other side to the bushings 10. Hydraulic cylinder of drive of middle retractable knife 6 is pivotally connected by housing 12 with rear side of dump 1, and by rod 13 - pivotally connected with horizontal tie-rod 9.

The bulldozer working member operates as follows.

When rod (13) of power cylinder (Figure 2.1) is retracted, horizontal rod (9) and bushings (10) connected to it are mixed along guide (7). Together with the bushings 10, the inclined rods 11 move in a plane parallel to the main knife, acting on the stiffening box 5 and causing it to move together with the retractable knife 6 along the guides 4 of the casing 3.

In the operating position of the retractable knife 6 (Figure 2.2), one of the ends (in this case, right) of the bushings 9 contacts the stops 8 of the horizontal guide 7, while an obtuse angle β≈95° is formed between each of the inclined rods 11 and the horizontal guide 7 on the side of the stops 8.

When digging the soil with a retractable knife, the digging force is perceived by the stiffening box 5 and transmitted to the inclined rods 11, compressing them and forcing them to turn clockwise (figure 2.2) relative to the hinge O (attachment of the inclined rods 11 to the bushings 10). The horizontal components of the forces transmitted from the stiffening box 5 to the inclined rods 11 press the sleeves 10 against the stops 8 and are received by the dump 1, thereby unloading the power cylinder rod 13.

It is possible to install the inclined rods 11 with respect to the stiffening box 5 and the horizontal rod 7 at right angles, however, in this case, when the hinges for attaching the inclined rods 11 to the stiffening box 5 and the bushings 10 are worn or inaccurate, folding of the inclined rods in one direction or another and corresponding loading of the power cylinder can occur. Therefore, in the proposed technical solution of the working member of the bulldozer, artificially in the working position of the retractable knife 6, a position of the inclined rods 11 is created in which a force is generated that presses one of the ends of the bushings 10 against the stops 8. Therefore, even when the above hinges are worn, loading of the power cylinder will not occur.

2.2 Advantage of development implementation

The advantage of introducing the proposed design with a controlled medium knife: an increase in the annual fund of work, an increase in annual productivity, the use of low unit capacity bulldozers on frozen soils and on soils of a high category.

Calculation of basic parameters

The main parameter of a caterpillar bulldozer is the nominal tractive force, which means the force developed by the base tractor on dense soil, taking into account its loading from the weight of the mounted equipment with a slip of not more than 7% and a speed of 2.5-3 km/h.

The main parameters of the bulldozer: the operational weight of the bulldozer; main operating speeds; specific forces on the cutting edge of the knife along the entire length of the dump, specific forces on the cutting edge of the middle knife of the dump, which determine the possibility of the bulldozer developing soils with different digging resistance.

Metrology and standardization

7.1 Main tasks of metrology

One of the existing factors that ensures the high quality of the obtained product is compliance with the specified accuracy of the product execution in the presence of mass production.

The desire to manage the quality of products requires the presence of knowledge and metrology, an analysis of the accuracy of its implementation and the possibility of its control. The unity of measurements in all sectors of the national economy is ensured by the state standardization system, which is responsible for metrological institutes and laboratories.

The most effective method of maintaining the unity of the measurement system is the use of standards.

According to GOST 1626370 "State Support System

Unity of measurements. Metrology, terms and definitions. " A standard is a measuring tool that ensures the reproduction and preservation of a unit in order to transfer its dimensions according to a verification scheme by a measuring tool. The standard is reproduced with the highest technological accuracy, sufficient at this stage of the development of science and technology.

The main tasks of metrology are:

the development of a general theory of measurements;

establishment of uniform physical quantities;

development of measurement methods and instruments;

setting of standards.

7.2 Main Standardization Tasks

Standardization - establishment and application of rules for the purpose of

Streamline activities in a particular area in favour of and with the participation of all stakeholders, in particular in compliance with operating conditions and safety requirements.

In the development of mechanical engineering, the organization of the production of machines and other products on the basis of interchangeability is of great importance. The standards are based on combining the achievements of science, technology, practical experience and determine the foundations not only of the present, but also of the future development of production.