A mechanical press applies pressure to a material to change its shape or size. They are used in various industries, including metal stamping and punching.
They have a number of advantages over hydraulic presses, including ease of set-up and operation and a lower environment risk due to no fluid use. They also offer high levels of control, precision, and accuracy.
Types
Mechanical presses apply a regulated force to a workpiece to shape, deform, and assemble products. These machines are commonly used in industrial manufacturing facilities and come in a variety of sizes and power sources.
A press can be a single, double, or multiple-ram or slide design. They can also be hand-powered or electromechanically operated. All types of presses exert force by radial movement of the mechanical components, which is converted into linear motion and exhibited as a pressing force on a workpiece.
Some of the main components that a mechanical press has include: drives, flywheels, clutches, break, and power systems. Drive motors are used to power the press; flywheels and clutches generate energy that powers the ram or slides in the press; and breaks allow for a braking function.
There are several types of drives that a mechanical press can use, including: swing, rack, and pinion, crank, and eccentric or crank drives. These types of drives are suitable for different applications and have different advantages.
Swing or eccentric drives have lower cost and a greater range of stroke than crank-driven presses, but they require a more complicated design and are not always as reliable. They are also more susceptible to damage and may require more maintenance than other types of drives.
Crank or eccentric driven presses have a longer ram-stroke and can produce higher amounts of force than other types of presses. They also have a more rigid construction and less tendency to redirection than other types of presses.
Hydraulic presses are a type of mechanical press that uses a hydraulic system with a hollow cylinder, piston, and power unit. The cylinder and power unit increase internal fluid pressure, which forces the piston within the cylinder to move along its axis, increasing the amount of force that can be applied.
Although hydraulic presses are capable of producing a larger amount of force than other types of presses, their tonnage rating is limited by the size of the cylinder bore and by limitations on the power unit’s ability to generate pressure. Additionally, they are prone to leaks and environmental contamination.
Components
A mechanical press is a machine that uses mechanical means to produce metal parts. It is commonly used in a variety of manufacturing processes, such as cutting, punching, bending, and forming. The basic components of a mechanical press are a frame, ram, and bed or bolster plate.
Each of these elements is designed to exert pressure on the tool or die, depending on which type of press you have. For instance, a single-slide (ram) press exerts pressure on its own tool or die, while a double-slide (ram) press has two rams that each work independently of each other.
Once the ram has created enough force on its own or on the tool or die, it retracts and the motor and flywheel begin a process of creating energy all over again. This process is repeated for each 360-degree cycle of the press, or stroke.
During each stroke, energy in the flywheel is consumed, and this causes the motor to slow. The energy is then restored on the next upstroke of the press.
In order to keep the press functioning at peak performance, it must be maintained properly. This requires scheduling routine preventative maintenance, and keeping common items and consumable replacement parts on hand to avoid downtime or unnecessary repairs.
The key to effective mechanical press maintenance is thorough inspection. Check for proper oil level, operating temperature, and pressure in the pump.
If the pump runs hot, it is likely due to cavitation from air entering the fluid being pumped. This can lead to early breakdowns and poor circuit performance.
Another important part of a mechanical press’s maintenance is checking the lift clearance. It is critical to maintain this because all presses wear down over time. If the lift clearance exceeds a certain amount, it is time for repair.
In general, mechanical presses are easy to set up and operate and offer high levels of precision and accuracy. This makes them a good choice for large-scale part production. However, they can also be costly if not maintained correctly. As such, it is essential to schedule routine maintenance at a time that works for your business and keep the right team members on hand to help.
Maintenance
The right maintenance procedures are essential to the long life of mechanical presses. Failure to follow them can result in significant breakdowns, requiring costly repairs and replacements.
Daily maintenance checks can save a company money and increase productivity. They can also help pinpoint any problems before they become serious.
A clean press makes it easier to spot oil leaks, air leaks, and breaks. Check the ram for oil drops (see Figure 1). Replace a broken seal when one is visible, and make sure bronze bushings are greased as necessary.
Regular oil inspections will ensure the proper amount of hydraulic oil is being pumped through the system. Over time, low or dirty oil will reduce its fluidity and efficiency. It will also reduce the life of the hydraulic system.
Monitor the oil temperature to catch any circuit components that are passing too much heat, which can lead to premature failure. The system can be run with either an air cooler or a water cooler to maintain an ideal operating temperature.
Another important maintenance procedure involves checking the press for stress. The frame should be inspected weekly for any cracks or other damage that could cause the press to not function properly.
The press’s operator should be able to tell when a problem occurs, such as a broken stud nut or loose bed bolt. They should be able to stop production immediately and call for help.
Investing in computerized maintenance management software is an excellent way to track and control all your maintenance tasks. This type of software will gather and store all maintenance information in a central database, allowing you to quickly identify and prioritize issues.
Preventive maintenance can reduce the number of total machine breakdowns, which will save a business money in the long run. It can also keep your equipment functioning well, enabling you to meet production schedules and sell products on time.
There are many different types of maintenance, each designed for specific scenarios. Taking the time to learn about all of them will help you decide which one is best for your needs.
Automation
As the business of metal forming continues to evolve, companies are looking for ways to maximize their production rates while also reducing operating costs. Automated equipment helps to meet this need, especially for presses that are used for a variety of applications.
In a traditional stamping and press operation, the feed of workpieces, the replacement of dies and the movement of the ram are all manual operations that can be made much more efficient by using an automation system. The main goal is to reduce the time it takes to complete an operation, which will help to lower operational costs and improve product quality.
There are several types of automation procedures, including the use of motors and actuators to create rotary motion. Actuators can be used to open and close valves, raise and lower heavy press-rolls and apply pressure.
Power press automation systems can help to simplify the changeover of dies, as well as to increase production rates. They can include swing-out platens that make the die replacement process easier and faster.
They can also be programmed to run at a specific stroke rate and strokes per minute, which will help plant operators to schedule their production and prevent downtime. Job storage and retrieval software can also be used to track all pressroom activities.
Other important automation functions involve monitoring job status, advancing feed lengths, checking progressive dies, varying press speeds and ensuring that all press functions are operating properly. Electronic controls have greatly improved this process by reducing downtime, engineering changes and plant maintenance.
Another automation procedure is the use of computer-controlled ancillary devices, such as transfer axes and air counterbalances. These can be adjusted by software for the correct die height, air counterbalance, and cushion air settings in one programming change, reducing downtime and engineering changes.
Besides saving time, press automation procedures can also help to improve safety. By reducing the amount of part handling that goes into a stamping or pressing process, an operator can stay outside of the die area and eliminate the risks that come with the manual operation of a mechanical press.
