Stepped shaft

Contents

Introduction

1 Purpose and principle of the article operation

2 Service purpose, technical specifications

and workability of the part

3 Analysis of existing process

part manufacturing process

4 Definition of production type and lot size

5 Substantiation of selection of method and method of procurement

6 Purpose of processing methods

7 Selection of process bases

8 Development of routing process

8.1 Determination of the number of processing steps for each surface

preparations

8.2 Workpiece Surface Treatment Sequence

8.3 Formation of process flow diagram

route

8.4 Construction of sketched process route

9 Substantiation of selection of equipment, accessories, cutting and

measuring tool

10 Calculation of operational dimensions

10.1 Calculation of long dimensions

10.2 Calculation of diametrical dimensions

10.3 Adjustment of workpiece dimensions

11 Calculation of cutting modes

12 Rationing of operations

13 Development of adjustment map or calculation and processing map

(RTC) for one of the operations

14 Design of special accessory

14.1 Design Input

14.2 Schematic diagram of the accessory

14.3 Calculation of fixing force with determination of characteristics

power drive

14.4 Calculation of the accessory for accuracy

14.5 Description of the designed accessory operation

15 Design of special control device

15.1 Design Input

15.2 Test diagram and schematic diagram of accessory

15.3 Calculation of the accessory for accuracy

15.4 Description of the designed accessory operation

Project Findings

List of sources used

Application

Introduction

The purpose of the course project is to acquire skills in the development of a route technological process for the manufacture of a given part - shaft, an operational technological process for the performance of individual operations, the design of machine tools and control devices.

In this course project, the development of a technology for processing a shaft-type part based on basic technology was carried out taking into account the achievements of modern machine-building production. The peculiarity of the project is the use of CNC machines, as well as semi-automatic machines.

1. Purpose and principle of the article operation

Reduction gears are used due to the need to reduce the speed of the actuator shaft to the required frequency, as well as to increase the torque on the output shaft. The main characteristics of the gearboxes are output torque and gear ratio.

Gearbox housing accommodates conical, helical, chevron and spur gears of external engagement fixed on shafts. Shafts are supported by bearings located in the housing.

2. Service purpose, technical characteristics and workability of the part

Shafts are designed to transmit torques and, in most cases, to maintain various parts of machines rotating with them relative to bearings. Shafts carrying the parts through which torque is transmitted receive loads from these parts and, therefore, work simultaneously on bending and torsion. By purpose, there are gear shafts on which gear wheels, sprockets, couplings and other gear parts are installed, and core shafts on which not only gear parts are installed, but also other parts, such as flywheels, cranks, etc.

Part - the shaft is made of structural carbon steel of grade 45 with subsequent strengthening of the surface layer, using TVH hardening to a depth of about 2... 3 mm.

As a result of the qualitative evaluation of the part for processability, the following conclusions can be drawn:

1. Part material - steel 45 GOST 105088 fully complies with operating conditions and requirements for strength, wear resistance and surface deformations.

2. The design of the part provides sufficient rigidity in machining on metal cutting equipment.

3. The shapes of the surfaces to be treated are not complex (mainly the surfaces of rotation); it is possible to maximize the use of standardized and normalized cutting and measuring tools.

4. The weight of the part is 20.31 kg .

5. From the point of view of providing the specified accuracy and roughness of the surfaces, the part is not complex, accordingly it can be considered technological.

3. Analyzing Existing Part Manufacturing Process

The existing process consists of draft, finish and final stages.

The workpiece for this part according to the existing process is obtained by the strip cutting method from rolled stock, so it has very large processing allowances. The weight of the blank is 30.22 kg.

Processing route:

1) Operation 005 - Procurement.

2) Operation 010 - Milling and Centering.

3) Operation 015 - Turning (rough turning). In this operation, we pro-process the external cylindrical surfaces of the part (surfaces 3, 4, 5, 6), prepare the bases for subsequent processing. Processing is carried out on a lathe with CNC 16K20F3 with removal of large allowances (significant cutting forces, low processing accuracy).

4) Operation 020 - Turning (rough turning). In this operation, the external cylindrical surfaces of the part (surfaces 7, 8, 9, 10, 11, 12, 13) are processed. Processing is carried out on a lathe with CNC 16K20F3 with removal of large allowances (significant cutting forces, low accuracy of about-work).

5) Operation 025 - Turning (finishing turn). Finish the cylindrical surfaces of the part (surfaces 3,4, 5, 6). This operation is the most time consuming in the manufacturing process of the part. Machining on a CNC lathe (the cutting forces are insignificant, the machining is precise, a number of surfaces are finally machined, the row is subject to subsequent finishing).

6) Operation 030 - Turning (finishing turn). Finish the external cylindrical surfaces (surfaces 7, 8, 9, 10, 11, 12, 13). Machining is done on a CNC lathe (insignificant cutting forces, precise machining). All surfaces are finished.

7) Operation 035 - Milling. In this operation, two key slots (surface 16, 17) are milled to the finished surface. The planes are processed permanently. Machining on Vertical NC Machine 6P13F3.

8) Operation 040 - Locksmith. Manual abrasive tool removes burrs and sharp edges after milling operation 035.

9) Operation 045 - Control.

10) Operation 050 - Thermal quenching by TVH heating. Quenching is carried out in an induction furnace.

11) Operation 055 - Control.

12) Operation 060 - Grinding. In this operation, cylindrical surfaces are finished, which are subject to high requirements for processing accuracy, geometry and surface roughness based on the service purpose of the part (these surfaces are design bases and determine the position of the actuating elements of the assembly structure).

13) Operation 065 - Flushing. Parts are washed after grinding (to remove chips and abrasive dust associated with the remains of the emulsion used in grinding the part).

14) Operation 070 - Control. It is carried out at the control area. This operation is final in the process plan.

The process is built according to the classic differential scheme of multi-stage processing using mentally and physically obsolete equipment and a significant amount of manual labor.

8. Development of routing process

8.1 Determination of the number of processing steps for each surface of the workpiece

Machining is necessary to achieve the specified surface accuracy and quality parameters most quickly and economically. At each processing step, micro-irregularities and a defective layer of the previous step are removed, and micro-irregularities and a defective layer of the implemented step appear .

At the rough stage, the main part of the allowance is removed (6070% of the total allowance) and processing is carried out in "rough" modes (small cutting speeds and large feeds). At the final stage, 1015% of the allowance is removed, and processing is carried out at higher speeds and lower supplies than at the final processing. At the final stage, 5% of the allowance is removed, and processing is carried out at even higher speeds and lower feeds.

9. Justification for selection of equipment, accessories, cutting and measuring tools

When selecting equipment, we are guided by the type of production. In the conditions of mass production, it is recommended to use universal, special machines and semi-automatic machines, machines with numerical software control. Preference is given to CNC machines because they can significantly reduce auxiliary time.

To install and secure the part, we use mainly universal devices, since the machined part is a body of revolution.

The analysis of surfaces of a detail showed that the detail can be processed by the universal cutting tool (cutters, mills, abrasive wheels). Serial manufacturing allows the use of several non-standard cutting tools in the process.

When selecting measuring instruments, they are subject to the following basic requirements:

- compliance with accuracy indicators of the checked element;

- maximum simplicity of design and minimum cost;

- speed.

We will mainly use standard measuring means, mainly not expensive. Special measuring tools and devices are used to control some surfaces.

Project Findings

The assignment for the course design was the design of the technological process for the manufacture of the shaft. During the project, the purpose and principle of the product, which includes the part, are disclosed. The service purpose and technical characteristics of the part are given. Based on the technical characteristics of the part, conclusions have been drawn about the possibility of obtaining it using existing processing methods using standard tools and equipment.

The production type defined in section 3 and the calculated lot size of the machined parts affected the equipment selection. Preference from-given to hardware with numerical software control.

The choice of the method and method of obtaining the workpiece is justified. The procurement has been pre-calculated. The calculation determined its dimensions, the weight of the figure describing the part, which affects the flow rate.

As a result of analysis of part surfaces (KP 151001.VTU09.08 01) according to the drawing, methods of its processing were assigned, technological bases, assumed basing diagrams were selected, number of stages of part surfaces processing and their sequence were determined. After that, a preliminary technological route for the manufacture of the part was developed.

Calculation of operational long and diametrical dimensions was followed by adjustment of the workpiece drawing (KP 151001.VTU09.08 02) and the route process (KP 151001.VTU09.08.03 SM).

Calculations of cutting modes and norms of processing time at drilling operation were made. The calculation of the time standards for the operation makes it possible to judge how many pieces of equipment are needed for its full load .

A calculation and processing chart for one of the turning operations has been developed (KP 151001.VTU09.08. 04 SM).

Special accessories are designed (KP 151001.VTU09.08.01 SS) and (KP 151001.VTU09.08.02 SS). The machine tool is designed for fixing force, and the control - for accuracy. Description of work of designed devices is given.

The graphic part consists of the above six sheets.

The developed routing process is documented on the process maps (Book 2).

Appendices to this book contain specifications of components and parts included in special accessories.