Multifunctional four-port directional control valve constructed from logic valves E. Lisowski a,⇑ , W. Czy _ zycki a , J. Rajda b a Cracow University of Technology, al. Jana Pawła II 37, 31-864 Kraków, Poland b PONAR Wadowice S.A., ul. Wojska Polskiego 29, 34-100 Wadowice, Poland article info Article history: Received 11 December 2013 Accepted 1 July 2014 Available online 23 August 2014 Keywords: Hydraulic valve Directional control valve Logic valve CFD analysis abstract The paper refers to four-port solenoid pilot operated valves, which are subplate mounted in a hydraulic system in accordance with the ISO 4401 standard. Their widespread use in many machines and devices causes a continuing interest in the development of their design by both the scientific centers and the industry. This paper presents an innovative directional control valve based on the use of logic valves and a methodology followed for the design of it by using Solid Edge CAD and ANSYS/Fluent CFD software. The valve design methodology takes into account the need to seek solutions that minimize flow resis- tance through the valve. For this purpose, the flow paths are prepared by means of CAD software and pressure-flow curves are determined as a result of CFD analysis. The obtained curves are compared with the curves available in the catalogs of spool type directional control valves. The new solution allows to replace the whole family of spool type four-port directional control valves by one valve built of logic valves. In addition, the innovative directional control valve provides leak-proof shutting the flow paths off and also it can control flow rate and even pressure of working liquid. A prototype of the valve designed by the presented method has been made and tested on the test bench. The results quoted in the paper confirm that the developed logic type directional control valve is able to meet all designed connection configurations, and the obtained pressure-flow curves show very good conformity with the results of CFD analysis. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Directional control valves are components of virtually any hydraulic system and hence they are subject to continuous devel- opment. A lot of scientific papers are dedicated to the issues of their performance characteristics improvement, such as papers of Amirante et al. [1–3], wherein CFD (Computational Fluid Dynam- ics) methods are more and more often used to analyze the design of directional valves. The similar trends in the application of CFD methods in the development of hydraulic system components can be seen in the papers of, among others, Del Vescovo et al. [4] Chattopadhyay et al. [5] and Pan et al. [6]. In the recent years there has been a growing interest in the technique based on logic valves for slip-in mounting, especially the poppet type ones, which is reflected in the catalogs of manufac- turers of hydraulic components, for example [7–10]. The develop- ment of those creates the possibility of higher internal tightness and greater speed of control, and the ability to build special sys- tems for large capacities of the volumetric flow rate, even several thousand liters per minute [11–14]. The logic valves are relatively new solutions, which are being systematically introduced to hydraulic controls and drives. A single logic valve has a simple structure that allows control of the flow direction through one flow path, depending on the given pressure control signal. Due to the fact that the usual working ele- ment has poppet type closing system, it is possible to obtain high internal tightness with almost no leakage. A single logic valve is usually not able to fulfill the function of a directional control valve which controls the direction of movement of a hydraulic cylinder or motor. Using a sufficient number of logic valves, theoretically, we can build a directional control valve for these advanced control functions [7,10,15]. Their assembly as a functional unit, such as four-port hydraulic directional control valve, is a relatively com- plex task [16]. Proposals of ready-made solutions are rare and, fur- thermore, does not take into account the applicable standards [17]. Application of ISO 4401 standard [18] enables mounting and connecting many different spool type directional control valves, as well as valves with different functions, to one type of subplate. http://dx.doi.org/10.1016/j.enconman.2014.07.008 0196-8904/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail addresses: lisowski@mech.pk.edu.pl (E. Lisowski), czyzycki@mech.pk. edu.pl (W. Czy _ zycki), janusz.rajda@ponar-wadowice.pl (J. Rajda). Energy Conversion and Management 87 (2014) 905–913 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman