Optimization of Manufacturing Processes by Reducing the Costs of Tools and Equipment on Hydraulically Operated High-Pressure Technological Lines

Abstract

Most technological manufacturing lines include hydraulically operated stationary tools, devices and equipment. During a manufacturing cycle, there are phases, usually short, in which part of the hydraulic cylinders of the drive systems concerned, with small gauges and displacement speeds, have to generate / maintain high clamping or pressing forces, which implies functioning at high working pressures. The solution for such cylinders is to use modular hydraulic pumping units comprising: oil tank; low-pressure electric pump; hydraulic directional valve for starting, stopping and changing the direction of displacement of the cylinder; electric pump pressure control valve; pressure filter; return filter; oscillating hydraulic pressure intensifier (minibooster mounted directly on the cylinder). Such pumping units, which consume low pressure (in the primary side of the minibooster) to generate high pressure (in the secondary side of the minibooster), are cost-effective when it comes to the procurement of components, installing them, the space required for installation, and their maintenance, too. The classic applications of using them are for achieving and maintaining high pressure values, either in volumes of closed spaces (endurance tests on pipes and tanks), or at the active stroke end of hydraulic cylinders (hydraulic presses). The authors demonstrate, on a laboratory test bench, the following: - The range of applications of such pumping units can be extended in a third direction, namely for actuation of hydraulic cylinders with low gauge / speeds and constant high load (high working pressure) over the entire stroke; - The uniformity of displacement of these cylinders with load over the entire stroke, fed and actuated by such pumping units, is weakly affected by the pulsating mode of operation of the hydraulic pressure intensifier.