Design And Fabrication Of Hydraulic Press

ABSTRACT

The paper presents the development of a manually operated hydraulic press which encompasses the design, fabrication and performance evaluation of the press. The components parts of the machine were designed using various design equations. The design results were used to select materials for various components. The detailed drawing of the developed machine was done using Pro E software. In fabricating the machine, mild steel was used as the locally sourced material. The use of mild steel is due to the fact that its strength, rigidity and machinability falls within the design specifications. Some components of the machine developed include; the frame, cylinder mounting table, press pin, working table/bed, hydraulic tank, and hand lever. Some of the bought out parts include: ram assembly, pressure hose, pressure indicator and hydraulic pump. In evaluating the performance of the machine developed, mild steel plate of length 220 mm, breadth 70 mm and thickness 20 mm was put on the machine working table. This piece of material was bent after pressing the hand lever. The pressure at which bending took place was read to be 50 bar as indicated on the pressure gauge. The machine developed was also used to press a sleeve of internal diameter of 85 mm and external diameter of 89 mm into the cylinder of an engine block at a pressure of 15 bar.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

1.1      INTRODUCTION

1.1      OBJECTIVE OF THE PROJECT

1.2      SIGNIFICANCE OF THE PROJECT

1.3      SCOPE OF THE PROJECT

1.4     LIMITATION OF STREET LIGHTING

1.5   APPLICATION OF THE PROJECT

CHAPTER TWO

2.0     LITERATURE REVIEW

2.1      OVERVIEW OF THE PROJECT

2.2      MACHINE WORKING PRINCIPLE

2.3      MACHINE APPLICATION

CHAPTER THREE

3.0     CONSTRUCTION

3.1      INTRODUCTION

3.2      DESIGN ANALYSIS OF SOME MACHINE COMPONENTS

3.3      COMPONENT DESIGN

3.3.1. Hydraulic Cylinder

3.3.2. Cylinder End-Cover Plate

3.3.3. Design for Bolts

3.3.4. Cylinder Flange

3.3.5. Flange  Thickness  Determination

3.3.6. Piston

3.3.7. Selection of Seals

3.4.     FRAME DESIGN

3.5.     DETAIL MANUFACTURINGPROCEDURE

CHAPTER FOUR

RESULT ANALYSIS

4.1      PERFORMANCE TEST RESULT

4.2      COST ANALYSIS

4.3      LABOUR COST

4. 4 OVERHEAD COST

4.5     SUMMARY OF COSTS

CHAPTER FIVE

5.1      CONCLUSION

5.2      RECOMMENDATION

5.3      REFERENCES

 

CHAPTER ONE

1.1                                                        INTRODUCTION

A hydraulic press is a device using a hydraulic cylinder to generate a compressive force. It uses the hydraulic equivalent of a mechanical lever, and was also known as a Bramah press after the inventor, Joseph Bramah, of England. He invented and was issued a patent on this press in 1795. As Bramah (who is also known for his development of the flush toilet) installed toilets, he studied the existing literature on the motion of fluids and put this knowledge into the development of the press.

The hydraulic press depends on Pascal’s principle-the pressure throughout a closed system is constant. One part of the system is a piston acting as a pump, with a modest mechanical force acting on a small cross-sectional area; the other part is a piston with a larger area which generates a correspondingly large mechanical force. Only small-diameter tubing (which more easily resists pressure) is needed if the pump is separated from the press cylinder.

Pascal’s law: Pressure on a confined fluid is transmitted undiminished and acts with equal force on equal areas and at 90 degrees to the container wall.’ A small effort force acts on a small piston. This creates a pressure which is transferred through the hydraulic fluid to large a large piston”.

This machine is powered by high-pressure fluid and used for working of materials by pressure. The first hydraulic presses were used at the end of the 18th century and the beginning of the 19th for such purposes as baling hay, pressing grapes, and squeezing butter. By the middle of the 19th century hydraulic presses were being widely used in metalworking for forging of billets, sheet metal stamping, die stamping, bending and straightening, volumetric stamping, extrusion of piping and structural shapes, packaging and briquetting of waste products, compressing of powdered materials, metal sheathing of cables, and so on. Hydraulic presses have also found use in making plastic and rubber articles, wood veneers, plywood, textolite, and the like. They are also employed in syntheses of new materials (such as artificial diamonds).

The operation of the hydraulic press is based on Pascal’s law. Its force is developed by a piston of a working cylinder to which fluid (water or oil) under high pressure is admitted. The piston in turn is connected to the working tool. A hydraulic press may be driven by a pump or by a pump-accumulator station with steam, air, hydraulic, or electromechanical actuation. The working cylinder may be either vertical or horizontal. The pressure of the working fluid is usually 20-32 meganewtons/m² (200-203 kilograms-force/ cm²), but in special cases (such as diamond syntheses) it may reach pressures of 450 meganewtons/m² (4,500 kilograms-force/cm²). The cost of metalworking on the hydraulic press is lower than the cost of hammering and the efficiency is higher. The hydraulic press does not require a heavy foundation and does not cause great vibrations and noise such as is inevitable during hammer operation.

1.2                                             OBJECTIVE OF THE PROJECT

The objective of this work is to fabricate a machine that is powered by high-pressure fluid and used for working of materials by pressure

1.3                                         SIGNIFICANCE OF THE PROJECT

A hydraulic press is used for almost all industrial purposes. But basically it is used for transforming metallic objects into sheets of metal. In other industries, it is used for the thinning of glass, making powders in case of the cosmetic industry and for forming the tablets for medical use. The other common uses of the hydraulic presses are as follows:

• For crushing cars. A hydraulic press is the heart of any car crushing system. In this process, a hydraulic motor applies a large pressure on the fluids into the cylinders. The fluid pressure makes the plates rise and with a large force, the plate is driven on the car thereby crushing it.
• Fat-free cocoa powder. While processing the cocoa beans, a liquid known as chocolate liquor is derived. For making fat-free cocoa powder, this liquid is squeezed out in a hydraulic press. After this stage, this liquid is processed further to make a powder. The powder thus derived is cocoa powder, which is fat-free.
• For sword making. In the process of making swords, a hydraulic press is used to give a flat shape to the raw steel.

1.4                                          APPLICATION OF THE PROJECT

A hydraulic press is very versatile and can be used in all kinds of applications viz:

Compacting Food and Other Consumables

Compressed food products are packed using hydraulic presses. Many popular meat and cheese products would not be possible without the use of a hydraulic press. Powdered make up and pills are often compressed using specialized hydraulic presses.

Making Appliances

Hydraulic presses are frequently used when manufacturing appliances. A hydraulic press might be used to create or assemble the electrical parts of a refrigerator, or stamp a panel. Microwaves, dishwashers, and laundry machines all require hydraulic presses for shaping panels and many of them require hydraulic presses for other uses as well.

Manufacturing Electrical Parts

A hydraulic press is often used in the manufacturing of electrical equipment used in major electrical installations. Housings and switches found in switching stations and elsewhere are assembled using a hydraulic press. The thermostats that help keep our houses, and businesses at the correct temperature are often manufactured using a pressing process.

Making Ceramics

Hydraulic presses are used to compress the particulate matter that makes up ceramics into their ceramic form. Ceramics see all sorts of uses; from potent magnets to most forms of industrial manufactured clay product ceramics help make the modern world possible. Ceramics are also used in body armor to keep soldiers and other people in dangerous situations safe. Some super high tech fields like semiconductors really entirely on ceramics.

Manufacturing Car Parts

Many of the parts of automobiles are shaped using hydraulic presses. From clutches, to gear and bearing assemblies, a hydraulic press helps make even the most vital car parts possible. Simpler products like windshield wiper blades are also manufactured using hydraulic presses. Hydraulic presses even see use in more precise manufacturing applications like fuel injection sensors. Hydraulic presses optimize many sorts of forming and stamping operations.

Building Aircraft

Similarly to with cars, the same or analogous parts of aircraft are built using hydraulic presses. In addition to things like windshield wiper blades and gear assemblies even the airplane body panels and wings are built using hydraulic presses.

Military Application

Hydraulic presses are used when loading shells and other ammunition related tasks. Hydraulic shop presses are often located aboard navy ships, or even outside the military in the merchant marines, in case emergency repairs are needed. Every single air force base probably has a hydraulic shop press located somewhere. There are numerous other military applications from making vehicle tires and tracks to fuel cell compression.

1.5                                               BENEFIT OF THE PROJECT

1) Hydraulic presses have the ability to compress any material to the maximum unlike their mechanical equals.

2) Hydraulic presses occupy only half the space taken up by mechanical machines because they are able to constrict large pressure in a small diameter cylinder.

3) They can deliver full exerted force anywhere in the stroke’s range thereby adding to its innate flexibility.

4) Hydraulic presses are easy to design according to the customers’ individual requirements.
5) You can modify tonnage or even maximize the time cycle for every job by using a hydraulic press enabling the user to be more productive through elimination of changing pressure, excessive ram pressure and maintaining/varying ram speeds via the cycle. If you modify the options for every job, you can maximize the cycle time.

6) Hydraulic presses can be built to any sophistication level; be it a simple exclusive cell press or a multi-purpose system that’s fully integrated, hydraulics are cost effective and easily altered for whichever task at hand.

7) Hydraulic presses’ components are readily available in the market at great affordable prices for both long term and up-front operations.

8) The hydraulic force principles enable creative engineering which include traditional multi-action, side-acting, up-acting and down-acting operations. Power systems can be positioned remote, below or above the force and press actuators.

9) The hydraulic relief valve incorporation into the hydraulic system offer in-built overload protection. No press-force can supersede the pressure it is enabled to build therefore restraining the maximum pressure obtainable controls extreme force.

10) The hydraulic presses have limitless control options ranging from basic relays to more complex PC or PLC control systems. In order to facilitate ease of work, operator interfaces can be included by storing specific job parameters or every dye. Hydraulic presses can be controlled for exact position and pressure including speed control, dynamic adjustments, present time performance variances and pressure holding. Speed and ram force can be controlled in any way with various precision levels.

11) Hydraulics enables high pressure generation over a small surface area. This potential minimizes the general structure needed to support the actuators force.

12) The control of the hydraulic press over the motions and forces permits the press to offer greater general quality of a manufactured part than several other kinds of presses.

1.6                                               LIMITATIONS OF PROJECT

This work is limited to designing a hydraulic press with:
i.  175mm cylinder stroke

1. 0-920mm adjustable bed height

iii. 510 mm table widths

1. Movable head for off centre pressing

1.7                                            PROBLEMS OF THE PROJECT

This machine is designed for heavy compression of a variety of objects along with cutting and punching of metal components in specific industrial assembly processes and applications. Modern press machines offer exceptional performance and reliability, which explains their widespread appeal and application in manufacturing. Like all tools, the hydraulic press can become damaged over time through heavy usage. Here are common problems associated with hydraulic press

1. Oil leakage: Oil leaks are the most reported problem with hydraulic presses. If your press is working well, you should not have an oil leak.  Oil leaks can show up on hydraulic lines, hose end fittings and around the ram.
2. Overheating: Another common problem with hydraulic presses is overheating. For optimal performance, your hydraulic press machine should not be running higher than 150° F. Higher temperatures will damage seal compounds and degrade the oil.

• Slow Pressure Build Up: When working at peak performance, your hydraulic pump should reach its required pressure in about one second.  Pressure buildups of over two seconds may signal a problem with the pump.

1. Abnormal noise is produced during operation.
2. High fluid temperature.
3. Slow in operation.

• Cavitational wear generate.
• At high speed, tiles is not produced properly.

1.8                                                  DEFINITION OF TERMS

• Bed – The main foundation and supporting structure upon which the operating parts of the machine are mounted and guided.
• Bolster: A Bolster plate is attached to the top surface of the press bed.
• Cylinder – Cylinder assembly consists of a cylinder, piston, ram, packing, and seals. Piston diameter and oil pressure determine the force (tonnage) that a given press can deliver.
• Daylight – The clearance from the bolster bottom (when fully retracted) to press bed.
• Frame – The main structure of the press containing the cylinder and the working surfaces.
• Stroke – Stroke length can be set for any distance within the stroke limits of the cylinder. Adjustments include: top of stroke, pre-slowdown point, and bottom of stroke.
• Throat Clearance – The distance from the vertical centerline of the ram to the frame member behind the bed. This distance determines the largest diameter piece that can be positioned with the part centerline under the center of the ram.
• Moving Plate – A plate which is mounted on the cylinder Ram and moves when the cylinder extended.
• Dual Push Buttons – A most common method of actuating hydraulic presses considering the safety of the operator.
• Pendant: Electrical control device with Push Buttons Mounted
• Work Height – The distance from the floor to the top of the bed.CHAPTER TWO

2.0                                                    LITERATURE REVIEW

2.1                                             OVERVIEW OF THE PROJECT

A hydraulic press is a device using a hydraulic cylinder to generate a compressive force. It uses the hydraulic equivalent of a mechanical lever, and was also known as a Bramah press after the inventor, Joseph Bramah, of England.^[1] He invented and was issued a patent on this press in 1795. As Bramah installed toilets, he studied the existing literature on the motion of fluids and put this knowledge into