A hydraulic press is a machine press that generates compressive force by the use of a hydraulic cylinder. It is a device that is used for lifting heavyweights with the application of a much smaller force. The hydraulic press was invented by Joseph Bramah in England. He accomplished the project in the 17th century (1795). Bramah has also developed some toilet-flushing materials used in our daily life.
Read more: How to Bleed a Hydraulic Clutch
The hydraulic press work is based on Pascal’s law. This law state that the intensity of pressure in a static fluid is transmitted equally in all direction.
The working principle of the hydraulic press is quite interesting and easy. Just as earlier mentioned, it uses Pascal’s law for its working. There are two cylinders of different diameters. The first cylinder is of larger diameter and it carries the ram, the other small cylinder carries the plunger.
These two cylinders are connected by a pipe that contains a liquid through which liquid is transmitted. Whenever a little force is applied to the plunger in the downward direction, pressure is produced. This pressure is produced on the liquid in contact with the plunger.
The pressure produced is equally transmitted to all directions and lets the ram play its role in the upward direction. While the heavier weight placed on the ram moves along with it.
You can the video below to have a full understanding of how the hydraulic press works:
Read more: Understanding hydraulic pump
Applications of Hydraulic press
Below are the applications of the hydraulic press machine:
Due to the wide application of this presser machine, it is used for converting any metal block to a sheet. The machine tool is used for blanking, forging, clinching, molding, deep drawing, punching, and metal forming operations.
Some other applications include:
- RTM (Resin Transfer Molding)
- Carbon Fiber Molding
- GMT (Glass Mat Transfer), and
- SMC (Sheet Molded Composites)
There are major parts that the hydraulic press comprises of, these parts include:
Safety door: the safety door is a correction gate that allows any workpiece to be fixed when damaged.
Limit switch: this part prevents the travel of an object in a mechanism. It is mechanically operated by the motion of the object.
Manual control valve: it aids the operation to be carried out manually using the valve.
Relief valve: the relief valve is used to release or control the pressure whenever it exceeds the limit of the valve.
Pressure gauge: this part is used to measure the pressure.
Hydraulic cylinder: a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke.
Oil tank: this is the reservoir that is used to store and supply hydraulic oil.
Passing plate: this plate is of high strength and used for exerting pressure on the workpiece.
Bailing compartment: the workpiece is placed in this part so it can be pressed. It can be adjusted to any shape and size of the piece.
The hydraulic press is categorized into five different types that play their effective role according to the feature. These include:
Four-column hydraulic press: this type is vast in its working, making it useful in most pressing operations like bending, punching, etc.
Universal hydraulic press: this presser is used on almost all pressing processes such as punching, forging, etc. Without any external attachment.
Single-column hydraulic press: it is also known as C-type. It has only one column and a C-type frame just as it’s being named.
Horizontal hydraulic press: pressure is applied horizontally or parallels to the axis of the machine. The workpiece remains between the vertical plate.
Vertical hydraulic press: unlike the single column, this type has two columns and there is an overarm connected to the columns. Yet, the pressure is applied vertically.
Read more: Understanding hydraulic jacks
Hydraulic press machine can be specified according to the followings:
- Vertical or down stroking.
- The frame they carry.
- Maximum load of pressing.
- The return capacity of the machine.
- A number of cylinders are inside the machine.
- Stroke of the ram.
- Cylinder types are either single or double acting.
- Speed of the ram in mm/sec.
- Electrical power consumed by the machine in KW. Finally,
- Operating method (automatic or semi-automatic).
Advantages and disadvantages of hydraulic pressing machine
Below are the benefits of the hydraulic press:
- It working is cool and quiet because there are less number of moving parts.
- A high amount of pressure is generated.
- High tonnage capacity.
- Greater versatility. That is the ability to adapt.
- Overloading or weight damage is not an issue.
- Smooth pressing.
- Simple design.
- Small floor space is occupied.
- Easy to operate.
- The rigidity and strength of the workpiece are improved.
- Longer tool life.
Despite the advantages of hydraulic press machines, some limitations still occur. The following are the disadvantages of this machine tool:
- Maintenance requirement and cost are high.
- Availability of carbon footprint.
- Limited pressure.
That’s it for this article “Hydraulic Machine Press” where I’ve examined its applications and working principles. Its types, specifications, advantages, and disadvantages have also been explained. I hope the knowledge is attained, if so, kindly comment, share, and recommend this site to other technical students. Thanks!