Development of the manufacturing process of the gear unit of the Model 6T13 machine feed box

Contents

Contents

Summary

Contents

Introduction

1 Tool Wide Universal Milling 

SF machine

1.1 Main components, description and technical characteristics of turning-screw machine 16K

1.2 Service purpose of the metal cutting machine assembly under consideration

1.3. General layout

1.4 Service purpose of a certain part of the metal cutting machine assembly under consideration

1.5. Machinability analysis of the metal cutting machine assembly in question

1.6. Service purpose of part of the considered unit of metal machine "Gear wheel unit"

1.6.1 Part Assignment

1.6.2 Analysis of part material

1.6.3 Systematization of part surfaces

1.6.4 Analysis of workability of part design

2. Identification of the type of production and selection of a strategy for the development of the technological process

2.1. Production volume and justification of production type

2.2 Selection and justification of procurement method

3. Development of part processing process, metal cutting machine assembly under consideration

3.1 Development of part processing process route

3.2 Development of baselines

3.3 Selection of process equipment

4. Development of technological operations

4.1 Selection of technological equipment

4.2 Cutting Tool Selection

4.3 Selection of controls -

4.4. Design tolerances of machined surface

5. Calculation of cutting modes

5.1.Turning of outer diameter

5.2. Hole Swelling

5.3. Chamfer turning

5.4.Trim ends

5.5. Drilling

5.6. Hole Drilling

5.7. Zubodolbezhny

List of literature

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Summary

In this course work, the main stages of the development of the technological process for machining the part "Gear Block," which is part of the speed box of the wide-universal milling machine model SF676, were considered.

Process development stages include analysis of unit and part processability, material characteristic, analysis of design and process bases, selection of initial workpiece, calculation of interoperability allowances on one of surfaces and calculation of cutting modes for two operations, namely lathe on NC machine and denture.

The explanatory note contains, and also includes roadmaps and operating maps and specification of the metal cutting machine assembly in question.

Graphic part of the term paper includes the assembly drawing, the drawing of a detail, a route of processing of a detail, technological adjustments.

Introduction

The steady, progressive development of the national economy is largely determined by the technical progress of mechanical engineering. For the national economy, it is necessary to increase the output of mechanical engineering products and improve its quality. This growth is carried out mainly due to the intensification of production based on the widespread use of the achievements of science and technology, the use of progressive technologies. Increasing production efficiency is possible by automating and mechanizing it, equipping high-performance CNC machines, industrial robots, and creating flexible production systems.

Technological progress in mechanical engineering is characterized not only by the improvement of machine structures, but also by the continuous improvement of their production technology. It is important to manufacture the machine in a high-quality, economical and timely manner with minimal costs.

The domestic machine tool industry has created high-performance machines for various technological purposes and progressive cutting tool designs that provide high processing intensity and accuracy.

Machine tool building is the most important branch of mechanical engineering. Machine tool technology studies the laws of the technological processes of machine tools manufacture, reveals the parameters, influencing which, it is possible to intensify their production.

Vertical cantilever - milling machine 6T13

Purpose and scope.

The vertical cantilever machine 6T13 is designed for milling all kinds of parts from various materials.

It is used in single and serial production conditions.

Vertical and horizontal planes, slots, angles, frames, gears, etc. are machined on the machine. The machine can operate in three modes: emergency, push and manual.

In automatic mode, the machine operates at various automatic cycles, including the frame cycle.

In push mode, the table is set to move. Markup work is possible. In manual universal mode, the machine works using working feeds, quick movements, as well as manual movements from the flywheels and handle.

There is a device to limit the gap in the helical pair of longitudinal movement of the table, individual lubrication of the vertical movement screw, which increases its durability and reduces the lifting force of the cantilever.

Additional devices for protection against spreading chips and emulsion are introduced.

Stiffness of machine is increased due to rectangular guides of frame and cantilever.

There is automatic braking of the spindle in operating mode and in case of emergency shutdown.

Automated lubrication of units increases their durability and reduces maintenance time.

The machine table can rotate about a vertical axis by ± 45 °, which allows you to mill various helical spirals using dividers.

The rotary spindle head of the machines is equipped with a mechanism for manual axial movement of the spindle sleeve, which allows processing of holes, the axis of which is located at an angle of up to ± 45 ° to the working surface of the table.

The power of the drives and the high rigidity of the machines allow the use of mills made of fast-cutting steel, as well as a tool equipped with plates made of hard and super-hard synthetic materials.

Mechanized tool attachment. The transverse feed screw is located along the axis of the cutter, which increases the accuracy of processing. Technological capabilities of the machine can be expanded using a dividing head, a rotary round table and other devices.

The possibility of adjusting the machine to various semi-automatic and automatic cycles allows you to organize multi-stage maintenance and use the machine to perform various work in in-line production.

The machine can be supplied in a country with a temperate, cold and tropical climate.

Machine accuracy class - H as per GOST 8 - 82E

The main design advantages of machine tools are:

mechanized attachment of the tool in the spindle;

a proportional feed retardation mechanism;

device for periodic adjustment of clearance value in helical pair of longitudinal supply;

safety clutch of supply drive protection against overloads;

braking of horizontal spindle at stop by electromagnetic clutch;

device for protection against spreading chips.

The main technological advantages of machine tools are:

various automatic operation cycles of the machine;

wide range of spindle rotation and table feed speeds;

high power of drives;

high rigidity;

reliability and durability.

The processing capabilities of the machines can be expanded by using a dividing head, a round turntable and other devices.

Service purpose of the metal cutting machine unit under consideration

The speed box is designed to obtain the rotation frequency of the spindle necessary to provide a technological operation. Rotation to the input shaft of the gearbox is transmitted due to V-belt transmission from the engine installed at the base of the machine pedestal. Rotation is transmitted to the spindle using gear wheel blocks that move along the splines on the shafts and engage the wheels to obtain the necessary gear ratio.

The gear wheel units are moved using handles located on the speed gearbox. When turning the handle, the cam located on the shaft assumes the position in accordance with the table of rotation speeds located near the handle. At the same time, the finger located in the slot of the cam drives the rod located on the wheel block, thereby moving the block along the shaft. The front end of the spindle has an internal conical bore with a Morse cone No. 6, into which the front center and other fixtures for fixing the blanks are inserted .

Machinability analysis of the metal cutting machine assembly in question

By the processability of the design of the product is understood a set of structural properties that allow you to conduct technological preparation of production, manufacture, operate and repair the product at the lowest cost of labor, funds, time and materials compared to the same type of design of products of the same purpose with the provision of established quality indicators (GOST 1883173). The processability of the assembly unit structure, which is an integral part of the product, must have the same properties and ensure the processability of the product, which includes it. The processability of the design is evaluated qualitatively and quantitatively.

Qualitative characteristics of the constructability include:

interchangeability;

controllability;

3) control suitability;

4) instrumental accessibility.

Taking into account all the above listed indicators in terms of qualitative indicators of processability, the given unit can be considered technological, since:

interchangeability of the box is ensured by a method of connecting it to the frame, namely by bolting; It should also be noted that all fits carried out during assembly are made using full interchangeability techniques;

the speed box has clearly defined basic parts (body and body cover), which serve as the basis for the assembly process;

adjustment of the axial distance between the shafts of the box is also provided;

during assembly, there is a free approach of simple standard tools to the places of attachment of mating parts, it is possible to exclude mechanical adjustment of parts during assembly;

the number of parts in the assembly assembly is brought to a minimum, and the standard and normalized ones are sufficiently used.

during assembly operations and during final assembly of the assembly, methods of control of assembly parameters are carried out.

body structure provides tool access to elements during manufacture, testing, maintenance and repair.

The following key indicators are used to quantify processability:

labour intensity of manufacture;

process cost;

level of workability of the structure in terms of labour intensity of manufacture;

level of processability at manufacturing cost.

Service purpose of the part of the considered unit of metal cutting machine "Gear wheel unit"

1.6.1 Part Assignment

This part is designed to transmit torque between shafts and change the number of revolutions of the spindle. The main base of the part is a splined hole. The actuating surface of this part is toothed rims. The wheel block has two gear rims, for this type of wheels the main technological bases are the surface of the hole and the larger end [2, p. 151].

Selection and justification of procurement method

As a workpiece, we select stamping on MCP. This type of workpiece is selected because the part is in the form of bodies of revolution. Also, this method makes it possible to obtain a blank with relatively small allowances and good surface quality and dimensional accuracy (1213 sq.) [4, p.137] The use of other types of stamping blanks is advisable in a large-scale type of production.

Development of baselines

Operation 015 - NC Lathe. External diameter and smaller end face are used as technological bases. Rotation of the workpiece is transferred using a three-cap cartridge.

Operation 025: Dental. As technological bases we use the surface of the hole and the larger end. Rotation of the workpiece is transmitted using a mandrel.

Selection of process equipment

The main factors determining the selection of process equipment are:

1) correspondence of dimensions of the machine working area to dimensions of the workpiece to be treated (for lathe - the largest diameter of processing above the bed, distance between centers, the largest diameter of the rod to be treated, etc.);

2) the possibility of achieving the required accuracy and roughness (determined in accordance with the accuracy class of the machine);

3) correspondence of kinematic data (spindle speed, table speed, etc.) to calculated values of these mode parameters;

4) compliance of machine power with the required design values;

5) ensuring the required equipment capacity;

6) the equipment shall meet the requirements of safety, ergonomics and ecology.

All of the above factors are satisfied by the selected equipment listed in Table 6.

Development of technological operations

4.1 Selection of technological equipment

When selecting machine tools for securing workpieces and tools, the following recommendations should be followed:

1) the accessory shall ensure materialization of the procurement basing process diagram received at the operation;

2) the accessory must ensure reliable fastening of the workpiece during processing;

3) the accessory shall be fast-acting, easy to operate;

4) in large-scale and mass production, the clamping of the blank should be carried out automatically;

5) The accessory shall be inexpensive and technological in operation and repair.

In single and small-scale production, standard and normalized devices should be preferred.

When turning, we use a center and a drive cartridge, we also use a fixed lunet for additional basing of the workpiece, since the part does not have sufficient rigidity due to its length. When milling the splines of the slots, we also use a leash cartridge and a center. The selected process equipment meets the characteristics of the machine. All accessories used during processing are listed in Table 6.

4.2 Cutting Tool Selection

Use the following guidelines when selecting a cutting tool:

1) selection of cutting tool is determined by method of machining, configuration and arrangement of surfaces .

2) tool material is selected based on the grade of the workpiece material, surface condition, type of treatment, period of resistance, cost.

3) geometric parameters of the cutting part are assigned based on the type of treatment, the shape of the surface being treated, and the material of the workpiece.

In single, small-scale and medium-scale production, standard and normalized instruments should be preferred.

During turning, select the thrust cutter GOST 2913291, plate T5K10, GOST 1905780, and when milling splines, select the worm cutter for spline shafts GOST 802786. The selected cutting tools are listed in Table 7.