project report on design of hydraulic press

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project report in hydraulic press design in pdf

ABSTRACT
In an attempt to alleviate the problem of the dearth of equipment in our laboratories in most of our higher institutions, a 30-ton hydraulic press was desgined, constructed and tested using locally sourced materials. The principal parameters of the design included the maximum load (300 kN), the distance the load resistance has to move (piston stroke, 150 mm), the system pressure, the cylinder area (piston diameter = 100 mm) and the volume flow rate of the working fluid. The major components of the press designed includes the cylinder and piston arrangment, the frame and the hydraulic circuit. The machine was tested for performance with a load of 10 kN provided by two compression springs of constant 9 N/mm each arranged in parallel between the upper and lower platens and was found to be satisfactory. The cost estimate for the hydraulic press was N47,890.00 (US$320) at prices in Benin City, Nigeria, as at the time of press manufacture.

Introduction
The development of engineering over the years has been the study of finding ever more efficient and convenient means of pushing and pulling, rotating, thrusting and controlling load, ranging from a few kilograms to thousands of tons (Sumaila 2002). Presses are widely used to achieve this. Presses, as defined by Lange (1975), are pressure exerting machine tools. They can be classified into three principal categories as: hydraulic presses which operate on the principles of hydrostatic pressure, screw presses which use power screws to transmit power and mechanical presses which utilize kinematic linkage of elements to transmit power (Niebel et al. 1989; Degarmo et al. 1997; Sharma 2005). In hydraulic press, the force generation, transmission and amplification are achieved using fluid under pressure. The liquid system exhibits the characteristics of a solid and provides a very positive and rigid medium of power transmission and amplification. In a simple application, a smaller piston transfers fluid under high pressure to a cylinder having a larger piston area, thus amplifying the force. There is easy transmissibility of large amount of energy with practically unlimited force amplification. It has also a very low inertia effect. A typical hydraulic press consists of a pump which provides the motive power for the fluid, the fluid itself which is the medium of power transmission through hydraulic pipes and connectors, control devices and the hydraulic motor which converts the hydraulic energy into useful work at the point of load resistance (Sumaila 2002; Sharma 2005). The main advantages of hydraulic presses over other types of presses are that they provide a more positive response to changes in input pressure, the force and pressure can accurately be controlled, and the entire magnitude of the force is available during the entire working stroke of the ram travel.

Advantages of Hydraulic Presses
The mechanical press has been the first choice of many press users for years. The training of tool and die makers and manufacturing engineers in North America has been oriented toward applying mechanical presses to sheet-metal pressworking. Modern hydraulic presses offer good performance and reliability. Widespread application of other types of hydraulic power equipment in manufacturing requires maintenance technicians who know how to service hydraulic components. New fast acting valves, electrical components, and more efficient hydraulic circuits have enhanced the performance capability of hydraulic presses.

Factors That May Favor the Use of a Hydraulic Press
Factors that may favor the use of hydraulic presses over their mechanical counterparts may include the following:

1. Depending on the application, a hydraulic press may cost less than an equivalent mechanical press.
2. In small lot production where hand feeding and single stroking occurs, production rates equal to mechanical presses are chieved.
3. Single stroking does not result in additional press wear.
4. Die shut heights variations do not change the force applied.
5. There is no tonnage curve derating factor.
6. Forming and drawing speeds can be accurately controlled throughout the stroke.
7. Hydraulic presses with double actions and or hydraulic die cushions are capable of forming and drawing operations that would not be possible in a mechanical press.