Development of the design of the rock conductor

Contents

Contents

1. Designing the Assembly Process

1.1. The purpose of the unit in the machine, a brief description of its design and revision of the drawings according to the current GOST

1.2. Analysis of assembly specifications with development of inspection diagrams according to specified requirements

1.3. Technological analysis of the assembly design with calculation of processability indicators

1.4. Select Methods to Achieve Assembly Accuracy

1.5. Development of the process diagram of the assembly and its explanations

1.6. Development of the process of assembly with filling of maps, technical normalization of time by elements

2. Part Manufacturing Process Design

2.1. Assignment of the part in the unit, revision of the drawing according to the current GOST, analysis of technical requirements, identification of technological tasks arising during manufacture and development of inspection schemes according to the specified requirements

2.2. Process analysis of part design with determination of processability indicators

2.3. Selecting a Workpiece Manufacturing Method and Sketching

2.4. Develop a route for machining the main surfaces of a part

2.5. Technical normalization of specified operations with calculation of basic time

3. Fixture Design and Calculation

3.1. Development of fixture diagram

3.2. Selection of mounting, clamping and other components

3.3. Drawing up a diagram of the forces acting on the workpiece and calculation of the clamping device

3.4. Purpose of technical requirements for accessory ensuring specified accuracy

LIST OF LITERATURE

Application

Development of technological processes of assembly of "Filter" assembly, manufacturing of "Flange" part; development of routing process of manufacturing and assembly of "Hull" part; development of the design of the device "Rock conductor."

Designing the Assembly Process

1.1. The purpose of the unit in the machine, a brief description of its design and revision of the drawings according to the current GOST

The purpose of the node in the machine, a brief description of its design.

The filter is a part of the block of the pump TsNG1/20 and serves for purification of pumped liquid. It is an assembly unit, which includes: welded body (3), filtering element (2), cover (1), spring (14), plug (9), set of gaskets (6,7,8). The filter is installed in the suction pipeline in front of the pump.

1.2. Analysis of assembly specifications with development of inspection diagrams according to specified requirements

Analysis of assembly specifications.

The specifications for this part will be as follows:

- test for strength and density with hydraulic pressure of 6 kgf/cm2 not less than 10 min. Leak and weaving are not allowed;

- test for tightness with pneumatic pressure of 4 kgf/cm2. Air is not allowed to pass.

Development of inspection schemes according to the specified requirements.

Since the main process requirements are strength, density and tightness tests, the test benches are required for these tests. During the tests, it is necessary to monitor visually or with the help of sensors the presence of leaks, sweating and air flow.

1.3. Technological analysis of the assembly design with calculation of processability indicators

Process analysis of the assembly design.

The constructability analysis shall be carried out according to the following parameters:

- ease of assembly

The filter includes several assembly units, which facilitates the assembly process.

- assembly tool access

Access to the assembly tool is easy because the assembly of parts is simple and the connection locations are easily accessible.

- assembly control

No special measuring tools are required.

- standard items in the assembly unit

The filter unit does not use standard products

Calculation of processability indicators.

1. Assembly factor.

Formula for calculation:

Conclusion: the design is not technological for serial production conditions, since almost all parts of the assembly unit are not standard.

1.4. Select Methods to Achieve Assembly Accuracy

The required accuracy of mating parts during assembly is provided by adjustment and individual fitting.

1.5. Development of the process diagram of the assembly and its explanations

The process diagram of the assembly is shown in Figure 1.

1.6. Process of assembly of product or assembly unit

specifying assembly equipment, accessories and tools

Normalization of assembly operations time

The task of time rationing occurs at various stages of the design of the assembly process.

When developing route technology, time standards are established for all operations of the technological process, revealing their structure and content. For mass production, when rationing, aggregate standards are used, for mass production, the calculation and analytical method of rationing is used.

When developing operating technology in mass production, the previously established time standards are corrected after individual changes are made to the content of operations (reduction and overlap of unit time elements, change in the structure of operations). Adjusted time standards are linked to the pace of work.

Unit time for assembly operation is determined by formula:

tpc = ∑top+ tobs + totd

where ∑top is the sum of the operational time for all assembly transitions in a given operation;

tobs - time of organizational service;

totd - time to rest.

Time values ​ ​ are taken according to standards.

The content of operations and time standards are developed in detail during automation of assembly processes, during multi-machine maintenance, as well as when using robots at the main assembly operations.

Part Manufacturing Process Design

2.1. Assignment of the part in the unit, revision of the drawing according to the current GOST, analysis of technical requirements, identification of technological tasks arising during manufacture and development of inspection schemes according to the specified requirements

Assigns a part to a subassembly.

The flange part is a part of the filter assembly. The flange is designed for reliable attachment of the filter to other parts by means of screw or stud connection.

Rework of the drawing according to the current GOST.

The operating drawing of the flange with all technical requirements according to the current GOST is shown in Figure 2.

Analysis of technical requirements.

a) limit deviations of dimensions and surface roughness:

- diameter 45 mm. is performed on the 9th quota with the main

deviation h;

- diameter 28 mm. is performed on the 9th quota with the main

deviation h;

- diameter 70 mm. is performed on the 9th quota with the main

deviation h;

- diameter 115 mm. is performed on the 9th quota with the main

deviation h;

- diameter 40 mm. is performed on the 9th quota with the main

deviation h;

- all surfaces are made with roughness Ra = 12.5 μm,

stern of the right end of the part, which is performed from

roughness Ra = 6.3 μm

b) material:

the used material steel 12X18H10T.

c) production type:

mass production.

Identification of technological tasks arising during manufacture.

You can use a single turn to create the contour of a part. To obtain the necessary accuracy and roughness, a finishing turn must be carried out.

2.2. Process analysis of part design with determination of processability indicators

Process analysis of part design.

We will evaluate the workability of the part design according to the following parameters:

- surface shape

A flange consists of simple geometric surfaces, such as cylindrical and planar surfaces.

- ease of handling

There are no hard to reach places, so the supply of tools is not difficult.

-Conformance of surface and roughness

All specified values of quotas and roughness correspond to each other.

The technological and measuring bases are convenient, which facilitates the orientation of the workpiece in the working space of the machine and the measurement.

The control operation is performed using standard tools, so you do not need to develop new tools.

Determination of processability indicators.

1. Material Utilization Factor (CIM).

Formula for calculation:

4. The unification factor of the part.

Formula for calculation:

2.3. Selecting a Workpiece Manufacturing Method and Sketching

Select how the workpiece is manufactured.

To obtain the workpiece, we will use the hot stamping method. Hot stamping is carried out on hammers and presses in open and closed dies, by extrusion, flexible, using various processes.

Among various methods, we will choose a method of hot stamping in closed dies. It is used to obtain forgings of a simple shape, mainly in the form of bodies of revolution. Method provides reduction of metal consumption by 30%, accuracy of dimensions corresponding to 12m quota, dense microstructure, high quality of surface layer, low roughness.

Sketching.

A blank drawing to obtain a flange is shown in Figure 3.

2.4. Develop a route for machining the main surfaces of a part

2.5. Technical normalization of specified operations with calculation of basic time

When designing each process operation (transition, installation), the following parameters of cutting modes are calculated:

- cutting depth t, mm;

- supply s, mm/v;

- cutting speed v, m/min;

- spindle speed n, rpm;

- main time to, s.

Depending on the type of process operation, all parameters are calculated according to the corresponding formulas. The operating technology for this part uses the following operations:

- turning;

- drilling.

The following dependencies are used to calculate all cutting mode parameters for each operation.

Turning.

Cutting depth t.

In case of rough turning and absence of restrictions on equipment power, stiffness of AIDS system is taken equal to allowance for processing; during finishing turning, the allowance is cut in two transitions or more. At each subsequent transition, you should assign a smaller cutting depth than the previous one. With the roughness parameter of the treated surface, Ra = 3.2 μm inclusive t = 0.5? 2.0 mm; Ra≥0.8 of micron, mm t=0.1÷0.4.

Feeding s.

During rough turning, the maximum allowable power of the equipment, the stiffness of the AIDS system, the strength of the cutting insert and the strength of the holder is taken. Recommended feeds during rough turning of external turning are given in Table 11 (p. 266 ,/2/), and during rough thinning - in Table 12 (p. 267 ,/2/).

Maximum values of feed at turning of steel 45, permissible by strength of hard alloy plate, are given in Table 13 (p. 268, ,/2/).

The final turn feed is selected depending on the desired surface roughness and cutter tip radius (Table 14, page 268 ,/2/).

When the slots are cut and cut, the amount of transverse feed depends on the properties of the material to be treated, the size of the slot and the diameter of the treatment (Table 15, p. 268 ,/2/).

Recommended feeds for shaped turning are shown in Table 16 (page 269 ,/2/).

Cutting speed v.

At external longitudinal and transverse turning and stretching it is calculated by empirical formula:

Drilling.

Cutting depth t.

At drilling, cutting depth t = 0.5D, at drilling, countersurring and unfolding t = 0.5 (D-d), where D - drill diameter, d - hole diameter.

Feeding s.

When drilling holes without limiting factors, we select the maximum allowable feed for the drill strength (Table 25, p. 277 ,/2/). When drilling holes, the feed recommended for drilling can be doubled up to two times. In the presence of limiting factors of feed during drilling and drilling are equal. They are determined by multiplying the table supply value by the corresponding correction factor.

Cutting speed v.

Drilling Cutting Speed

Values of Cv coefficients and degree indices are given for drilling in Table 28 (page 278 ,/2/), for drilling, sanding and deployment - in Table 29 (page 279 ,/2/), and values of persistence period T - in Table 30 (page 279 ,/2/).

Total correction factor for cutting speed, taking into account actual cutting conditions,

where Lp is the operating length; i is the number of passes; n - spindle rotation speed; s - feed.

Calculation of all values for each transition, as well as values of coefficients, which were used, are given in Annex 1. The resulting cutting parameters are shown in Table 1.

Table 1.

Cut Parameter Values

Fixture Design and Calculation

3.1. Development of fixture diagram

For the drilling operation, we develop an accessory - a rock conductor. The rock conductor arrangement (Figure 4) is designed to handle four holes in the flange. The conductor is a bushing, which includes a housing (1), a conductor plate (2) with a set of conductor bushings (6) moving along the rockers, a support (3) with a mounting pin. The case, konduktorny plate are manufactured of SCh18, konduktorny sleeves - of tool steel U10, an adjusting finger and a support - of Steel 20X with cementation and the subsequent zaalka.

3.2. Selection of mounting, clamping and other components

To set the workpiece in vertical position, we base it on internal diameter and end face. To do this, a finger element is used, which is pressed into the stand (3). Support is attached to conductor housing by means of four bolts.

Part is secured by movable plate (2) of rock conductor through spherical washer (7).

Required arrangement of holes is provided by required set of conductor plates.

3.3. Drawing up a diagram of the forces acting on the workpiece and calculation of the clamping device

Diagram of forces acting on the workpiece is given in Fig. 5.

Figure 5: Q is the clamp force, M is the drilling torque.

Note the formula for determining the clamping force Q:

3.4. Purpose of technical requirements for accessory ensuring specified accuracy

1. Nonparallel of base of support relative to surface A is not more than 0.05 mm.

2. Non-perpendicular axes of bushings relative to surface A are not

more than 0.02 mm.

List of literature

1. Handbook of engineering technologist. In 2 vols. T.1/Edited by A.G. Kosilova and R.K. Meshcheryakov. - 4th edition, redesign. and additional - M.: Engineering, 1985, 665s., il.

2. Handbook of engineering technologist. In 2 tons. T. 2/Edited by A.G. Kosilova and R.K. Meshcheryakov. - 4th edition, redesign. and additional - M.: Engineering, 1985, 496s., il.

3. Engineering technology: In 2 tons T. 2. Machine production: Textbook for universities/V.M. Bartsev, A.S. Vasiliev, O.M. Deev and others; Ed. G.N. Melnikov. - M.: Publishing House MSTU named after N. E. Bauman, 1999. - 640 s., Il.

4. Machine tools: Handbook. In 2 t ./Ed. council: B. N. Vardashkin (before) and others - M.: Engineering, 1984. - T. 1/Ed. B. N. Vardashkina, A. A. Shatilova, 1984. 592 s, silt.

5. Machine tools: Handbook. In 2 t ./Ed. council: B. N. Vardashkin (before) and others - M.: Engineering, 1984. - T. 2/Ed. B.N. Vardashkina, V.V. Danilevsky, 1984. 656s, silt.

6. Machine tools, Kosov N.P., M: Mechanical engineering, 1968, p. 216

7. The basics of device design: Textbook for universities. - 2nd ed., Redesign. And additional - M.: Engineering, 1983. - 277 s., Il.