How to calculate of Power Press calculation

Mechanical Power Press is a useful sheet metal machine for bending, cutting, pressing, and shaping work pieces into various sizes and forms. It is typically utilised in metal fabrication companies and shops. This multi-tasking piece of equipment uses a press mechanism to compress and shape the appropriate material. The apparatus is capable of clamping the sheet of metal between its tools. Its basic frames are defined by its force or tonnage, as well as its working length. Power Press Machines are widely accessible in the market in both standard and customized configurations. 

Mechanical power presses are devices that generate force and execute metalworking operations such as cutting, punching, and bending by utilizing mechanical energy. They are usually made composed of a motor, a flywheel, a clutch, and a ram that travels up and down to deliver force to the workpiece. 

Types of Mechanical Power Press 

Power presses can be classified in several ways, such as by mainframe type, driving mechanism type, or task activity (mechanism).

Mechanical power presses are further categorized according to their frame design, driving system, and operating type. Among the most prevalent types of mechanical power presses are:

Types of Frames

Power presses of various types, including the c-frame type and h-frame type for metal sheet machining work used in the manufacturing industry, are readily available on the market.

1. C-Frame Power Press:  These can be used for a variety of operations and have a C-shaped frame that makes it simple to access the work area. The press frame has more angular and longitudinal deflection than other frame types because of its c shape. 

2. Hybrid Frame or Ring Frame:  H-frame and C-type frame designs are combined to create ring frames. The c-type frame press serves as the front support in this design. The open size makes it more rigid and deflection-resistant. For power presses weighing 110 to 250 tonnes, it is helpful. Precision of job operation and tool life will both increase with H-frame designs.

3. H -Frames/Straight Side Frames With Tie Rods:  The frame bodies of these pillar frames are also of the box type, but they are divided into four sections: the pillar 1, pillar 2, crown, and base or bed. Hydraulic tie rods are provided for all four of these components. These are employed for high-speed, high-precision operations and have a straight frame.

Drive Mechanism Types
               Although slider crank mechanics are a need for all power presses, there are three different crank kinds. They are the crankshaft, eccentric shaft, and eccentric gear.

1. Eccentric Gear Crank Mechanism:  Parts of the crank and gear are combined. It's a reliable system.

2. Crankshaft mechanism:  They transform the rotary action of the motor into the linear motion of the slide using a rotating crankshaft. It is used with compact power presses that can press up to 250 tonnes (at times up to 400 tons). For high stoves, it is not appropriate.

3. Eccentric Shaft Crank Mechanism:  It is simple and reliable for presses with very little stroke force and high speeds.

Job Operation Basis (Mechanism)
                    The following are the basic tasks performed by power presses:

1. Blanking Power Press:  The blanking press is utilised in applications for punching and notching. They can be found with high-speed processing in 4-column types and c-type frame designs to meet specific manufacturing needs.

2. High speed stamping power press:  The high-speed stamping press is appropriate for producing precise components at a low cost with excellent cutting precision. High production rates and low cost per piece are guaranteed by these quick and durable equipment.

How to Calculate  Mechanical Power Press Design Calculation Methods

Power Capacity (Pr)	=	45 Ton
Stroke Length (St)	=	100 mm
Rated Distance	=	3.974 mm
Stroke per Minute	=	75 SPM
Rated distance	=	(1-cosα°)St/2
3.974	=	(1-cosα°)50
α°	=	23°
Torque transmitted by the Crank Shaft in Mechanical Press
Tc	=	Pr. sin23°
	=	45 X 10³ × 50X10‾³ × sin23°
	=	879.14 Kg.m
	=	880 Kg.m
Tc  (1.15%)	=	1015 Kg.m
Power Need for Electrical Motor in Mechanical Press
P	=	E × (Stroke Per Min.) ÷ (60×0.8×0.8)
	=	(45 × 104 × 3.974 × 10‾³ × 75) ÷ (60 × 0.8 × 0.8)
	=	3492.77 Watt
P	=	3.5 KW
But it is standard motor is 3.7 kw = 5 HP
Flywheel Rim Design Process and we are determining flywheel rim weight, flywheel width in Mechanical Press, Flywheel are used to store energy. We suppose that the size value is determined
Rim OD	=	590 mm
Rim ID	=	390 mm
mean dia	=	490 mm
Flywheel Speed  (N2)	=	350 rpm
Flywheel Speed  (N2)	=	332.5 rpm (Fluctuation 5%)
Flywheel Energy  (E )	=	½mv²
Flywheel Velocity (v)	=	πDN÷60)
E	=	1015 Kg.m) above value
E	=	½m × [(πdN1 ÷60)² - (πdN2 ÷60)²]
1015	=	½m × [(3.14×0.49×350÷60)² -(3.14×0.49×332.5 ÷60)² ]
m	=	256.9 Kg
Now we can find out width and flywheel material is cast iron.
Use a clutch in a mechanical press to control the power supplied from the flywheel shaft to the crank shaft in engaged and disengaged states. Right now, we're learning how to choose a clutch capacity in a mechanical press.
Back shaft torque is
Tb	=	Tc ÷ (Gear Ratio)
Gear ratio	=	4.66 (it is a ratio of crank shaft and back shaft )
Tb	=	880÷4.66
	=	188.84  kg
Tb   (1.15%)	=	236  kg.m
Mechanical Press Force Chart
This chart Identify the load versus crank displacement. In this graph, load and crank angle are not constants. Nonetheless, the load will remain constant in the range of 0 to 4 mm. And the minimum load produced by this press machine is 10 tonnes.