Exchange rate by technology

Contents

Introduction

General part

Part material and its properties

1. Process Part

1.1. Select Procurement Type and Method

1.2. Define dimensions, tolerances and machining tolerances for workpiece surfaces

1.3. Define Stock Weight

1.4. Calculation of material utilization factor

1.5. Type of production and its technical and economic characteristics

1.6. Calculation of allowances by analytical method

1.7. Development of routing process of part manufacturing

1.8. Selection and description of process equipment

1.9. Selection and description of machine tools

1.10. Selecting and Describing a Cutting Tool

1.11. Selection and description of measuring tool

1.12. Calculation of cutting modes by operations

1.13. Calculation of technical time norm for operations

Literature

Introduction

The life of a modern man is inconceivable without machines that assist him in work, in movements over close and long distances that contribute to meeting his material and spiritual needs. In a person's life, a machine serves as a means by which a technological process is carried out that gives him the necessary material or cultural benefits. Thus, any machine is created to carry out a certain technological process, the result of which is a useful product for humans.

Human society constantly feels the need for new types of products, or for reducing labor costs in the production of mastered products. In both cases, these requirements can only be met by new processes and new machines required for their implementation. Therefore, the incentive to create a new machine is always a new technological process, the possibility of which depends on the level of scientific and technological development of human society.

The resources of work in human society are of the highest value. Therefore, a person has always sought to save labor in any business he does. Creating a machine, a person sets himself two tasks:

1) make the machine high-quality and thereby provide labor savings in the production of products produced with its help.

2) spend less labor in the process of creating and ensuring the quality of the machine itself.

The way to create a machine is complicated. The idea of ​ ​ a new machine arises when developing the technological process of manufacturing products, the production of which has arisen. This idea is expressed in the form of the wording of the service purpose of the machine, is the initial document in the design of the machine. To manufacture the designed machine, a technological process is developed and based on it a production process is created, as a result of which a machine is obtained, which is necessary to carry out the technological process of manufacturing the product and meet the necessary need.

In order to create a high-quality machine with the lowest cost of work, it is necessary, first, to design machines based on its service purpose and provide connections of material properties and dimensional connections embedded in the design of the machine.

Secondly, it is necessary to build the links of the production process in strict consistency with the system of links contained in the design of the machine.

The process of creating a machine from the formulation of its official purpose to the receipt in its finished form is clearly divided into two stages: design, manufacture. The first stage is completed by designing the machine and presenting it in the drawings. The second is the implementation of the design using the production process. The construction and implementation of the second stage constitutes the main task of engineering technology.

This course project was developed on the basis of recent advances in technology, progressive latest forms of production with a high level of mechanization and automation of technological processes.

General part

Description of part design and its operational purpose (general purpose)

Currently, gears and gears are widely used in many machines and mechanisms. They are designed to transmit and change torque. The operation of the gear is characterized by high reliability, the ability to withstand high loads and work in various conditions.

According to the classifier, this part belongs to the type class "bodies of revolution."

The process characteristic of the gear is determined by the technological classifier of parts of mechanical engineering and instrument making.

By main process characteristics:

1) dimensional characteristic:

- largest outer diameter, mm 139

- width, mm 35

- diameter of central hole, mm 40

2) material group - Steel 25HGT GOST 4543-71

3) view of the part by process characteristic.

According to the process classification of parts processed by cutting:

a) initial billet - stamping on MCP

b) quota

- external surface h11

c) roughness parameter Ra 2.5

d) mass characteristic 2.8 kg

The gear drawing contains all the necessary information about the part.

Consider all machined shaft surfaces to establish the machining method.

In the center of a gear wheel has a through opening of Ø40H7 of mm with a shponochny groove width 12Js9. Hub is made with diameter 65 mm, width 350.2. Dividing diameter of gear teeth is 125 mm, diameter of teeth vertices is 139h11, width of rim is 250.32.

Surface with diameter Ø40H7 has roughness Ra 1.25; surface of teeth roughness Ra 2.5. The remaining surfaces are made 14 square meters, roughness Rz 40.

Tolerance of radial run-out of diameter 139h11 relative to surface A - 0.15; tolerance of end run-out of hub side surfaces relative to surface A is 0.1.

These requirements are necessary to ensure kinematic accuracy in transmission.

We analyze the processability of the part design.

According to the part drawing, we install:

1) all surfaces of the part can be manufactured using a standard tool;

2) the workpiece can be obtained by stamping, which will provide the lowest metal consumption to the chips during machining;

3) the design of the part is rigid.

Based on the analysis, it can be concluded that the design of the shaft is technological and does not cause production difficulties.

Process Part

1.1. Select Procurement Type and Method

When selecting the procurement type and method, consider and compare the following process factors:

- production type - serial;

- part purpose - gear;

- part design - body of revolution;

- maximum size - Ø139 mm;

- part weight - 2.8 kg;

- material is GOST 454371 steel 25HGT.

Based on these characteristics, we choose stamping on horizontal forging machines (GCM).

The horizontal forging machine is designed for forging forgings such as rods with thickening at the ends, bushings, etc. The advantage of stamping on GKM over stamping on hammers and presses is higher productivity, the possibility of stamping without burrs, obtaining forgings without metal waste to form holes during punching and providing a good fibrous macrostructure. Stamping is made of piece blanks or bar. The die has three parts: a fixed die in the seat of the bed, a movable die in the movable cheek and punches fixed in the main slide of the machine. The stamped rod is fed until stop and clamped by dies. The die has a connector along two mutually perpendicular planes, due to which the overlaps on the forgings and stamping slopes are small or absent. When the punch moves towards the matrices, the forging shape is obtained due to the metal filling of the plane of the closed matrices. During the reverse movement of the machine, the punch and the movable die return to the initial position and forging is removed from the stream. Stamping on the MCP is carried out in several transitions in streams, the axes of which are located one above the other. Each transition corresponds to one working stroke of the machine.

The design of the process of forging forging on the MCC is carried out taking into account the basic rules for landing, which exclude the occurrence of a longitudinal shield and scrap on the clamps. Forging on GKM produces forging with weight from 0.1 to 100 kg with maximum diameter of 315 mm. Stamping on GKM is one of the productive methods and can be profitable for a certain type of billets. Performance up to 100 forgings per hour. Stamping is made from bars and pipes of hot rolled metal of increased accuracy up to 400 mm long and with a diameter of 20 to 270 mm. Sometimes cold-stretched steel is used, which significantly improves the accuracy of forging. Tolerances and allowances for forging made on MCC are regulated by GOST 750555.

Technical characteristics of the production method

billet on horizontal forging machine.

Weight, kg < 200

Precision quota... 14 2

Ra, μm 12.5... 3.25

Blacksmith slopes, deg Matrix 0

Punson 0.5... 3

Relative cost,% 70-75

Forging characteristics:

Accuracy class - T4

Steel Group - M1

Degree of difficulty - C1

Parting surface - P (flat)

Source Index - 11

1.5. Type of production and its technical and economic characteristics

The serial type of production is characterized by the production of a limited range of products, which is periodically repeated. The products are put into production in series and the parts are processed in batches at predetermined intervals.

The series refers to the number of structurally and technologically identical products launched into production simultaneously or sequentially.

The repeatability of the manufacture of the same products economically justifies the use, along with universal and specialized equipment, devices and tools, leads to a specialization of work places. Fast-changing machine machines, manipulators, CNC machines are widely used, which makes it possible in serial production conditions to increase labor productivity and reduce the activity of the production cycle.

In serial production, a technological process is developed in detail, which allows reducing processing allowances and improving the accuracy of blanks.

Large-scale production specializes in the production of products of a relatively narrow range of products in large quantities. It is characteristic of many processes in mechanical engineering, for shoe and sewing enterprises. The fixing factor is 2-10.

1.8. Selection and description of process equipment

Based on the design features of the part, the shaft, as well as depending on the type of production, the following equipment is selected for the production of the part.

Operation 005 and 010 Turning

Lathe 16K20F3 is used in these operations

Machine is designed for treatment of external and internal surfaces of parts such as bodies of revolution.

Technical characteristics of the machine.

The largest diameter of the workpiece to be processed, mm:

above the frame 400

above caliper 200

Naib. length of workpiece to be processed, mm 1000

Cut Thread Pitch:

metric, mm up to 20

Spindle speed, rpm: 12.5-2000

Number of spindle speeds 22

Largest displacement of caliper, mm:

longitudinal 900

cross 250

Caliper supply, mm/min:

longitudinal 3-1200

transverse 1.5-600

Number of feed stages b/s

Speed of quick movement of caliper, mm/min:

longitudinal 4800

cross 2400

Electric motor power, kW 10

Weight, kg 4000

Operations 015 Dental

Zubofrezerny semiautomatic device 53A20

Technical characteristics.

Largest workpiece diameter, mm 200

Maximum dimensions of cut wheels, mm:

module 6

tooth length of spur wheels 180

angle of teeth inclination, ° ± 60

Largest diameter of worm cutters to be installed, mm 125

Distance from table end to cutter axis, mm 160-410

Distance from tool axis to blank spindle axis 25-200

Greatest axial movement of cutter, mm 170

Tool spindle speed, rpm 75-500

Feed, mm/v, blanks:

vertical or longitudinal 0.45-120

radial 0.11.6

Electric motor power, kW 8.5

Operations 020 Long

Horizontal-extension machine 7B55

Technical characteristics.

Nominal traction force, kN 100

Longest sled length, mm 1250

The size of the support surface of the plate, mm 450 × 450

Hole diameter, mm:

in the base plate for the faceplate 160

in tablet 125

Working stroke speed, m/min 1.5... 11.5

Recommended speed of retraction, m/min 20... 25

Electric motor power, kW 18.5

1.9. Selection and description of machine tools

When developing the technological process of machining the workpiece, we choose devices that should contribute to increasing labor productivity, processing accuracy, improving working conditions, eliminating preliminary marking of the workpiece and reconciling them when installed on the machine.

Operations 005 and 010 Turning

In this operation we use:

- self-centering three-shoulder cartridge:

Boss of 71000035 GOST 3675-80

Operation 015 Toothfreezer

In this operation we use:

- mandrel with split collets for precise works:

Mandrel 71121464 GOST 31.1066.02-85

Operation 020 Long

In this operation we use:

- spindle mandrel with pneumatic clamp:

Mandrel 71121487 GOST 31.1066.02-85

1.10. Selecting and Describing a Cutting Tool

When designing the machining process of a workpiece, the selection of the cutting tool, its type, design and dimensions is largely predetermined by the machining methods, the properties of the material to be machined, the required machining accuracy and the quality of the workpiece surface to be machined. The cutting tool must be selected according to appropriate standards and reference literature, depending on how the parts are processed.

Based on the design, configuration, and precision requirements of the part, the following cutting tool should be used.

Operation 005 and 010 Turning

As cutting tool we select:

- lathe deflected left cutter with hard alloy plate T15K6, GOST 18877-73

b × h = 16 × 25 mm - section of the cutter holder;

L = 140 mm - cutter length;

Cutter geometric parameters:

α = 45 - rear angle, γ = 45 - front angle ,

φ =45 ° - a corner in the plan, r = 1 mm

Cutter Symbol:

Cutter 21020056 GOST 18877-73

- lathe boring cutter with hard alloy plate T15K6 with a plan angle of 60 °, GOST 18882-73

b × h = 20 × 25 mm, L = 240 mm;

Cutter geometric parameters:

α = 30°, φ =60°

Designation:

Cutter 21400083 GOST 18882-73

- solid machine sweep with conical shank as per GOST 1672-80

d = 40 mm - diameter;

corner in the plan φ =5 °; front angle γ = 5 °; rear angle α = 8 °.

Operation 015 Toothfreezer

As cutting tool we select:

- worm mill of accuracy class B as per GOST 932480.

module m = 5 mm; diameter d = 100 mm; length l = 100mm

Operation 020 Long

- keyway 12 mm wide according to GOST 23360-78:

Keyway 12, GOST 25160-82

1.11. Selection and description of measuring tool

When designing a workpiece machining process for interoperative and final inspection of machined surfaces, it is necessary to use a standard measuring tool, taking into account the type of production, but when appropriate, a special measuring tool or instrumentation should be used.

In mass and large-scale production, it is recommended to use limit calibers (braces, plugs, templates, etc.) and active control methods, which are widespread in many branches of mechanical engineering.

In steps 005 and 010, the lathe is selected as the measuring tool:

- the caliper of ShTs11250,1 of GOST 16689, range of measurement is 125 mm, the price of division of the nonius of 0.1 mm;

- caliber-clamps 40H7, 139h11 GOST 1835573. Designed to control smooth outer cylindrical surfaces;

- template on chamfer 1.6. Designed to control chamfers.

In operation 020 Extension, we select:

- caliper of ShTs11250,1 of GOST 16689;

- caliber-plug 12Js9 GOST 1481069.