PD mechanical engineering technology, pump housing part

Contents

CONTENTS

Introduction

1 Analysis of source data

1.1 Brief description and service purpose of the part

1.2 Basic Process Analysis

1.3 Purpose and objectives of the diploma project

2 Process Design

2.1 Process inspection of part drawing

2.2 Definition of production type

2.3 Selection of procurement type and method

2.4 Development of routing process

2.5 Calculation of allowances and interoperative dimensions

2.6 Selection of equipment and equipment

2.7 Calculation of cutting modes and time standards

2.8 Conclusions on section

3 Engineering of technological equipment

3.1 Purpose and operating principle of clamping fixture for paw milling

3.2 Determination of required clamping force

3.3 Purpose and Operating Principle of Eight-Spindle Drill Head

3.4 Boring cutter strength and stiffness calculations

4 Ensuring Life Safety

4.1 Analysis of harmful and hazardous factors of the manufacturing process of the housing

4.2 Safety and protection of CNC machines

4.3 Calculation of protective grounding

4.3.1 Ensuring electrical safety

4.3.2 Calculation of protective grounding

5 Technical and economic calculations

5.1 Process Efficiency Assessment

5.1.1 Calculation of capital investments

5.1.2 Calculation of process cost

5.2 Calculation of basic parameters and operational planning of the serial production area

5.2.1 Calculation of manufacturing cycle duration of parts batch

Conclusion

List of literature

Appendix A

Appendix B

PAPER

The explanatory note contains ___ sheets, 9 figures, 22 tables, ___ sheets of format A1, 22 sources, 2 annexes.

PROCESS, WORKING STROKE, TRANSITION, FEED, SPEED, CUTTING TOOL, ACCESSORY.

The object of development is the housing, which is part of the vacuum pump.

The purpose of the work is to develop a progressive technological process for the manufacture of the hull and its equipment in relation to the conditions of Penzcompressormash OJSC.

As a result of the work, the technological process of manufacturing the Hull part and technological equipment were developed, allowing to master the production of this product at an industrial enterprise.

Degree of implementation - the developed technological process can be used at Penzcompressormash OJSC.

The developed process equipment can be used in the manufacture of parts of a similar class for vacuum pumps of other modifications and models.

The effectiveness of the developed technology is confirmed by the calculation given in the work.

ANALYSIS OF INITIAL DATA

Brief description and service purpose of the part

Purpose and operating principle of the article

Part under consideration - "Housing" is a part of "Vacuum pump." This product belongs to the class "Liquid-ring rotary machines."

The "Housing" part is multifunctional in its operational purpose:

serves as a stationary base for vacuum pump shaft supports;

provides installation of vacuum pump due to presence of paws for fixation on foundation.

provides gas suction and injection due to the presence of internal cavities and external nozzles in the structure of the part;

provides hydraulic gate and fluid circulation in vacuum pump.

The main working surfaces of the part are (sheets 2 and 3):

- two-stage central hole (∅105N9 and ∅86N9). It provides fitting of axle boxes and bushings, sealing with soft packing. The above-mentioned parts constitute the hydraulic gate units of the vacuum pump.

is the inner surface of the ∅375N7. Provides fit and installation of gas distributing disks.

is the inner surface of the ∅395N9. Provides landing and installation of the housing.

- left end face and outer surface of the ∅185js7. Ball bearing cover is fitted and installed.

Part Material

For production of casting of a product gray cast iron - GOST 141285 SCh20 is used. Cast iron smelting is performed in induction furnace IST016; IST-018.

Chemical composition

Carbon (C)................................. 3,3 ÷ 3,50 %

Manganese (Mn)................................ 0,7 ÷ 1,0 %

Silicon (Si)................................. 1,40 ÷ 2,4 %

Phosphorus (P)......................................................................................................................................................... less than 0.2%

Sulphur (S)............................................................................................. less than 0.15%

Mechanical properties

Temporary resistance at stretching: σвр = 160 MPas.

Hardness: HV 170... 241.

The purpose of the casting is general purpose.

The nature of casting is casting for parts calculated for strength at pressure exceeding the working pressure of the product.

List of controlled quality indicators: appearance, dimensions, chemical composition, mechanical properties, presence and nature of defects on critical (working) surfaces of the part.

Thermal treatment of the article

Before machining the housing, it undergoes heat treatment - artificial aging. Heat treatment is performed for:

- relieving internal stresses arising during cooling of metal after its pouring into molds;

- elimination of structural heterogeneity;

- obtaining the required mechanical properties.

Heat treatment mode

The species is artificial aging.

Temperature at loading - not more than 400 ° С

Temperature at exposure − 700 ° C? 800 ° C

Speed of heating, °C/hour - 100 ÷ 150

The holding time is 4 hours.

The level of mechanical properties shall comply with GOST 141285.

Purpose and objectives of the diploma project

The production of vacuum pumps is currently constrained due to the high cost of their manufacture.

The situation can change with a significant decrease in the cost of pumps.

In this diploma project, an attempt was made to reduce the cost of production and processing labor by introducing CNC machines. The main objectives of the project are:

1. Progressive process design.

2. Development of technological equipment.

3. Feasibility study of the effectiveness of the new project.

PROCESS DESIGN

Part Drawing Process Inspection

The working drawing of the part "Housing" serves for the development of the process and adjustment of machines. It must contain all the information that gives you a complete view of the part.

The housing drawing fully complies with the requirements. The drawing shows all dimensions with the required deviations and roughness of the machined surfaces.

There are all the necessary projections and sections of the part that uniquely determine its configuration.

Detail material "Case" - SCh20 of GOST 141285 is well processed by cutting, is fragile, has average wear resistance and susceptibility to variable loadings.

Processability is a set of properties of a part structure that determine its adaptability to achieve optimal costs during production, operation and repair for given indicators of quality, volume of production and conditions of work performance.

A part is technological if:

in the process of its manufacture, minimum labor costs, materials and minimum cost are ensured;

in the process of technological preparation of part production, minimum costs for its design and technological preparation of production are provided.

The Housing part is complex in the configuration of the exterior and interior profile. Therefore, molding is carried out using rods that form both internal cavities and external elements: ribs, hooks, bosses. These elements are determined by constructive considerations and are difficult to change.

The developed process version has a large number of machining operations, they for the most part do not pose significant technological difficulties. The surfaces of the part allow processing per pass and allow the use of high-performance cutting modes.

The highest requirements are for the following surfaces:

Central hole (∅105N9 and ∅86N9) - roughing and finishing are carried out on a horizontal boring machine.

Internal surfaces ∅375N7 and ∅395N9 - rough and finishing are carried out according to one control program on a NC turning and carousel machine.

Outer surface ∅185js7 - Roughing and finishing are carried out on a NC turning and carousel machine.

Conclusion: The Housing part is easy to manufacture, no tools and accessories of complex design are required during machining, it is advisable to use CNC machines.

Selection of equipment and equipment

The selection of equipment for the developed version of the technological process is carried out based on the technical requirements for the manufacture of the part, its geometric shape, accuracy of the given dimensions, processing conditions and material, taking into account the selected type of production - medium-size .

Let's take a closer look at the technical characteristics of the main process equipment.

1. CNC Turning and Carousel (mode. 1512F3)

Turning and carousel machines are designed for processing heavy blanks of large diameter and small length. All kinds of turning work can be carried out on these machines, including turning of the external and internal surfaces, drilling, countersinking and unfolding of holes located along the axis of rotation of the part, thread cutting by marks. These machines may be provided with additional milling and grinding devices.

The horizontal arrangement of the machine plate facilitates the installation and attachment of blanks, as a result of which carousel machines are widespread in heavy machine building.

A mod machine. 1512F3 is equipped with an NC NC system. These devices are designed to control machines of the main type. They have a rigid structure, are self-contained for each machine and control the processing by program in the code ISO7 bits prepared in advance for each part.

NC class devices are built on the principle of a digital model or digital machine. In a digital model device, all operations necessary to control the machine are performed in parallel with separate units. The systems are designed to control complex machines with three or more coordinates.

The main technical characteristics of the machine:

1. The largest parameters of the workpiece being processed are:

- diameter: 1120 mm;

- height: 1000 mm;

- weight: 6000 kg.

2. Plate diameter: 1120 mm.

3. Frequency of rotation of the faceplate: 1.25 ÷ 250 min.-1.

4. The supply is vertical and horizontal: 0.1-4.5 min-1.

5. Motor power of the main drive: 30 kW.

6. Overall dimensions of the machine:

- length: 2920 mm;

- width: 2705 mm;

- height: 4100 mm.

7. Machine weight: 14800 kg.

2. Longitudinal milling machine (mode. 6605)

The Model 6605 Longitudinal-Milling 2-Spindle Machine is a general purpose machine and is designed to process parts made of ferrous and non-ferrous metals, various alloys and plastics.

The main method of machining on the machine is the treatment of planes with end cutters.

In addition, on the machine it is possible to mill planes with cylindrical milling cutters, process slots and ledges with disk milling cutters, use end, shaped and angular milling cutters.

The considerable capacity of the spindle drives, the wide ranges of speeds and feed and the sufficient rigidity of the machine allows both conventional and high-speed milling on it, as well as the treatment of high-alloyed, stainless and heat-resistant steels and light alloys.

The machine can be used in single, mass production of machine-building plants, as well as in repair and tool shops of various industries. The relatively high degree of automation of the machine allows for its productive operation in production lines.

The main technical characteristics of the machine:

1. Cone for attachment of tool in retractable spindle:

- Morse No. 3.

2. Distance between ends of horizontal spindles, mm:

- smallest: 340

- largest: 740

3. Distance from horizontal spindle axis to table surface, mm:

- smallest: 25

- largest: 600

4. The largest weight of the workpiece: 1500 kg.

5. Spindle rotation speed: 16 sound1600 min-1.

6. Number of spindle speeds: 22

7. Feed:

- spindle head: 10 sound800 mm/min.

- table: 10 sound3000 mm/min.

8. Spindle head motor power: 11 kW.

10. Overall dimensions of the machine:

- length: 5400 mm;

- width: 3520 mm;

- height: 2330 mm.

11. Machine weight: 13600 kg.

3. Drilling and milling machine (mod. 2431C)

The machine is designed to perform finishing operations on parts weighing up to 300 kg, when high accuracy of the machined holes and surfaces is required, as well as their mutual arrangement. The machine is equipped with an optical reading device.

The main technical characteristics of the machine:

1. Largest diameter of drilling in medium hardness steel:

50 mm

2. Table dimensions, mm: 750 × 500

3. Limits of revolutions per minute: 10-3000 min-1

4. Spindle motor power: 2.8 kW

5. Overall dimensions of the machine:

- length: 1900 mm;

- width: 1580 mm;

- height: 2300 mm.

6. Machine weight: 3300 kg.

4. NC Radial Drilling Machine (mod. 2M55F2)

The CNC radial drilling machines are designed for non-detectable and non-conductive processing of holes, mainly fasteners, in body parts, covers, flanges plates, etc. Their use is advisable in small and medium-sized production conditions.

Radial drilling machine with NC modes. 2M55F2 is equipped with an outdated but very reliable C68 Coordinate NC device. This device controls coordinate movements of the table according to the program specified on the five-track punch tape in BTsK5 code. The program includes setting information about the working progress of the tool, spindle speed, tool supply, processing cycle of each hole, etc.

Designed for drilling, boring, countersinking, unfolding, stretching holes, thread cutting by throwers, as well as other similar operations in the processing of various body parts.

The main technical characteristics of the machine:

1. Largest diameter of drilling in medium hardness steel:

50 mm

2. Spindle departure (distance from the spindle axis to the generatrix of the column): 450 wave1500 mm

4. Distance from the lower end of the spindle to the plate:

470 ÷ 1500 mm.

5. The greatest vertical movement of the hose along the column:

680 mm.

6. Largest axial movement of spindle: 350 mm

7. Spindle Cone: Morse No. 5

8. Highest tool weight: 30 kg

9. Number of spindle speeds: 18

10. Limits of RPM per minute: 30 sound1700 min-1

11. Spindle motor power: 4.5 kW

12. Overall dimensions of the machine:

- length: 2625 mm;

- width: 968 mm;

- height: 3265 mm.

11. Machine weight: 4100 kg.

When selecting a cutting tool, they are primarily guided by manufacturing technology, equipment used, part material and technical requirements. The body is made of gray cast iron CH 20 GOST 141285, for the treatment of this material it is recommended to use a cutting tool equipped with hard alloy plates VK6, which allows you to conduct processing at increased cutting modes and without compromising the accuracy of the dimensions and surface roughness. For turning operations, the standard GOST tool is mainly used. A special boring cutter installed on the mandrel is used on the turning-carousel machine to spread the inner surfaces (angle in plan - ¼ = 90 °). For treatment of the central two-stage hole (∅105N9 and ∅86N9), coordinate boring cutters are used as per GOST 2598783.

Drills according to GOST 1090377, gauges according to GOST 326681, countersinks of workshop manufacture are used for processing of holes for fastening elements. A specially designed elongated drill ∅8N14 is used to treat the oil hole (for lubrication of the pressure mechanism) ∅8 (L = 243.5 mm). For treatment of planes (supports for fundamental fixation, external branch pipes) end nozzle cutters with plates of solid alloy VK6 according to GOST 2435980, mandrels according to GOST 1378668 are used. End cutters with hard alloy crowns BK6 are used for processing of slots in supports.

In general, the equipment of the developed version of the machining process with a cutting tool satisfies the conditions for obtaining a high-precision high-quality part with high labor productivity and with less capital costs for it.

When selecting measuring instruments, the main requirement is the qualitative and fast control of the obtained dimensions, both during the processing and after it. To control the diametrical and linear dimensions of the 14th quota of accuracy, calipers are used as per GOST 16689. For surface cleanliness control, roughness samples as per GOST 937893 are used. A large number of special measuring tools are used (gauge for checking the alignment of holes, templates for checking the profile of chamfers, etc.)

With regard to the organization of work on the site, for the convenience of the main workers (machine tools), the following measures are provided:

1) Pre-assembly of technical documentation, blanks, tools, accessories and delivery to the workplace is carried out by the auxiliary personnel serving the production;

2) Installation and removal of accessories, adjustment of the machine for this operation is carried out by fitters;

Tool sharpening - centralized.

In connection with the use of CNC machines at the enterprise, the Bureau of CNC Machines is organized as part of the service of the department of the chief technologist, which develops and implements control programs.

Maintenance and repair of the machine fleet is carried out by the chief mechanic service, as well as the software systems maintenance bureau, which is part of the main electronics service.

On the site there are provided places for storing blanks and finished parts, a place for the foreman and BTK.

Conclusions under section

Comparative analysis of the initial and calculated data allows to distinguish the following advantages of the developed process over the basic one:

Reducing the time spent on support techniques;

Increasing productivity;

Increase in the proportion of regular time;

Reduction of piece time;

The equipment is located in the process;

Savings from making a more accurate casting with a lower mass;

Allows to reduce the share of highly skilled manual labor;

Reduces the labor input of the workpiece;

Reduces the production area.

PROCESS EQUIPMENT DESIGN

Purpose and Operating Principle of Clamping Fixture for Paw Milling

Milling device with pneumatic hydraulic drive (sheet 9) is intended for basing and fixing of blanks of "Housing" type when milling legs in size 5301.75 with end cutters on longitudinal milling machine 6605. The process base is a hole ∅375N7 and an adjacent end. Clamping is performed by 2 clamps (pos. 1).

Accessory housing (pos. 4) is a cast of gray cast iron CH 20 of box shape. On the housing there is a ring (pos. 5) and support (pos. 6), as well as grabs (pos. 1). Ring (pos. 5) it is necessary to mask the blank into the accessory along the hole ∅375N7. supports and ring are attached by screws (pos. 14) to the accessory housing. The accessory is based on the machine table using prismatic keys (pos. 10). Keys are made of steel 45. Eye bolts (pos. 17) are intended for transportation of the accessory. The accessory set includes pneumatic hydraulic booster (pos. 3). Pneumatic hydraulic booster is used in cases when there is no hydraulic station on the machine, but it is necessary to provide a large clamping force of the workpiece. The accessory is installed on the machine table, it is based by keys (pos. 10) and fixed with 4m machine bolts.

The principle of operation of the device is as follows:

1) The blank is installed in the accessory.

2) Cutters with the help of probes and installations (pos. 9) are set to a size of 5301.75.

3) Turn the handle of the 4-position control valve, which is located on the pneumatic hydraulic booster air under the pressure of 0.4 MPa is supplied from the factory pneumatic system to the left cavity of the pneumatic hydraulic booster.

4) The grabs are rotated and simultaneously moved downwards, thereby pre-clamping the blank.

5) Then turn the control valve with your hand, supply air to the right chamber of the pneumatic hydraulic booster, as a result of which the piston moves to the left, cutting off the oil from the left chamber of the pneumatic hydraulic booster with the rod.

6) Moving further to the left, the rod creates an operating pressure of 8MPa in the upper cavity, thereby finally clamping the blank in the appliance.

7) The operating pressure is created due to the difference in the cross-sectional areas of the piston ∅180 and the plunger ∅40.

8) Air must be supplied to LH chamber of pneumatic hydraulic booster by means of control valve to perform expansion of billet.

9) The piston and rod will move to the right, oil through the hole in the support enters the left cavity of the pneumatic hydraulic booster. As a result, the oil pressure in the upper cavity will decrease significantly from 8 MPa to 0.4 MPa.

10) Then air is supplied to lower chamber of hydraulic cylinders by means of control handle. The pistons will move up. The grabs will begin to move upwards while simultaneously turning around the axis. The workpiece is expanded

11) The blank is unloaded from the accessory.

Purpose and Operating Principle of Eight-Pin Drill Head

The eight-spindle drill head (sheet 10) is designed to drill 8 holes ∅23 simultaneously on the vertical drilling machine 2G175.

The drill head structure comprises a composite body 1, inside of which there are gears. Using radial bearings (pos. 40) the ends of the spindles and shafts are fixed. Cover is closed from above (pos. 19). Flange (pos. 2) which is necessary to secure the drill head to the spindle of the machine. Traffic jams (pos. 20, 21) are necessary for filling and draining oil, for lubrication of gears.

The head is attached to the machine using a flange (pos. 2). Shank (pos. 24) is inserted into the spindle hole of the machine. Flange (pos. 2) is tightened with 2 bolts (pos. 42). The spindle of the machine transmits torque to the shank (pos. 24) and further to the drive shaft (pos. 6). Torque from the drive shaft is transmitted to four intermediate wheels (pos. 8), and then eight wheels connected to the spindles (pos. 9).

In the spindle (pos. 9) bushings (pos. 10), in which there are conical holes for drill shanks.

The head is based on the diameter of the ∅375e8 conductor plate (pos. 30) into the hole ∅375N7 on the blank.

CONCLUSION

In the basic process, the replacement of universal machines with CNC machines and the use of technological equipment led to increased processing accuracy, increased labor productivity, reduced production preparation cycle, and reduced labor input.

Analyzing the obtained technical and economic parameters of processing the part of the basic and design version, we see that the proposed technology is labor-saving and energy-saving.

Also, the cost of manufacturing the part is significantly reduced and capital investments in production are reduced.

The annual economic effect can be about 300,000 rubles.

You can conclude that it is advisable to introduce a new process plan into production.