Hydraulic Press

 Hydraulic Press

"The hydraulic press is device used for lifting heavy weights by the application of much smaller force."

A hydraulic press is a machine press 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.

Working Principle of a Hydraulic Press

A Hydraulic press work on the principle of pascal's law which states that-"Intensity of pressure in a static fluid is transmitted equally in all directions"

Construction of a Hydraulic Press

The hydraulic press consists of the two cylinders of different diameters. One of the cylinder is of large diameter & contain a ram, while other cylinder is of small diameter & contain a plunger. The two cylinder are connected by a pipe. The cylinder & pipe contain a liquid through which pressure is transmitted.

Working of a Hydraulic Press

When a Small force F1 is applied on the plunger in the downward direction, a pressure is applied on the liquid in contact with the plunger. This pressure is transmitted equally in all directions & act on the ram in upward direction. The heavier weight placed on the ram is then lifted.

Let W= Weight to be lifted

F1= Force applied on plunger

F2= Force applied on Ram

A1= Area of plunger

A2= Area of Ram

P= Pressure intensity produced by force F1.

Pressure of fluid due to the application force F₁

${\displaystyle P={F_{1} \over A_{1}}}$ ..........................(1)

Resulting force F₂ on the larger cylinder due to the pressure of the fluid. With A₁ and A₂ being the areas of cylinder 1 and 2 respectively.

${\displaystyle F_{2}=PA_{2}=F_{1}{A_{2} \over A_{1}}}$ ....................(2)

${\displaystyle {F_{2} \over F_{1}}={A_{2} \over A_{1}}}$ .....................(3)

A small effort force acts on a small plunger. This creates a pressure which is transferred through the hydraulic fluid to apply a greater force on the larger ram.

Types of a Hydraulic Press

1. Single column hydraulic press

2. Four column hydraulic press

3. Vertical hydraulic press

4. Horizontal hydraulic press

5. Universal hydraulic press

1. Single column hydraulic press- As the name suggests this machine have single column & C type frame.

2. Four column hydraulic press- It's have four column & generally used for Bending & Punching operations.

3. Vertical hydraulic press- This types of hydraulic press consists two column & over ram connected with the column. In this types of press the pressure applied vertically.

4. Horizontal hydraulic press- In this types of hydraulic press workpiece is place between two vertical plates & pressure is applied horizontally or parallel to the axis of machine.

5. Universal hydraulic press- This types of the hydraulic press used in multitasking operations like forging, Punching, Blanking, Bending etc without any external attachments.

According to tonnes

1. 63 T Hydraulic Press Machine

2. 100 T Hydraulic Press Machine

3. 150 T Hydraulic Press Machine

4. 200 T Hydraulic Press Machine

5. 250 T Hydraulic Press Machine

6. 300 T Hydraulic Press Machine

7. 315 T Hydraulic Press Machine

8. 500 T Hydraulic Press Machine

9. 630 T Hydraulic Press Machine

10. 800 T Hydraulic Press Machine

Parts of a Hydraulic Press

1. Safety door
2. Limit Switch
3. Manual Control Valve
4. Electric Control Valve
5. Relief Valve
6. Pressure Gauge
7. Hydraulic Cylinder
8. Motor
9. Oil Tank
10. Pressing Plate
11. Bailing Compartment

Advantages of a Hydraulic Press

1. Built-in overload protection.
2. Greater versatility compared to the mechanical press.
3. It is compact.
4. It is quiet in operation.
5. It is safe compared to the mechanical press.
6. Lower initial and operating cost.
7. It offers a full-power stroke.
8. Lower tool cost due to built-in overload protection.

Disadvantages of a Hydraulic Press

1. Handling of hydraulic oil can be messy.

2. There are chances of hydraulic fluid leakage.

3.Hydraulic lines could burst due to excess pressure.

4. Some hydraulic fluids can catch fire.

5. The system gets heated because the hydraulic fluid is forced through the pumps.

6. It has a low operational speed.

7.They have relatively high energy consumption.

Application of a Hydraulic Press

1. Metal presswork (to press sheet metal to any required shape).

2. Drawing and pushing rods.

3. Bending and straightening any metal piece.

4. Packing press.