Field of the invention

The technical solution deals in hydraulic equipment for locking device locking device with hydraulic cylinders in parallel connection designed for railway turnouts switch rail setting.

The state of the art

Currently known and used hydraulic locking devices designed for the railway turnouts switch rail setting apply either independent hydraulic drive for each single locking device, or the central hydro-drive unit equipped with hydraulic cylinders in the parallel or series arrangement. The switch rail movement synchronization with locking devices equipped with more hydraulic cylinders is carried out by means of consecutive start up of the single hydro-drive motors, or by their revolutions electronic control. In terms of common hydro-drive of the hydraulic cylinders with series arrangement the compromising synchronization is secured by the principle of serial arrangement of the circuit itself, with adding of the set of transfer valves, which secure the operation under different cylinders geometry volumes and in dependency with working conditions (the resistance when adjusting). As to parallel connection, in the field of railway practice there are known some solutions with manually adjusted throttling of the hydraulic fluid flow into single cylinders and using of self-synchronising ability of the switch rails in the switch. Moreover the other smart solutions are known with electronically controlled proportional valves with fluent regulation of the fluid flow.

The emergency manual throw-over of the locking device is commonly applied via external manual pump by means of swinging, or rotating movement with application of the three-way valve for the function change. We know the solution with application of the electric motor shaft for manual setting by means of crank and fast running drive-box, which increases the electric motor revolutions within the process of the manual setting.

The limitation of the single cylinders maximal setting force is solved with individual drives by means of transfer valves, or with mechanic clutch with controlled slipping. As to system with common hydro-drive, we know the principle of mechanic dogs equipped with telescopic endings and with compression springs as well.

The disadvantage of the individual hydraulic drives and described synchronization of the running is the perplexity and demandingness of manufacture process. Another disadvantage is the spatial exigency of independent drives and deterioration of the system of tamping and maintenance. The disadvantage of series arranged systems is the high demandingness for pressurization of the system and this way the increased jeopardy of pressure liquid leakage and possible failures in the system. To secure the maximal setting force limitation on the single cylinders is a very difficult task. The synchronization is carried out by the jump system of the single cylinders filling. Currently known systems with parallel connection from the view of principle have not solved the synchronization of the single cylinders piston rods movement when the geometry volume differs one from another. Known solution with stable adjusted flow throttling in the single cylinders is dependent with hydraulic liquid temperature and with setting resistance of the switch in single points of the setting. The switch rails self-synchronization ability may be applied just for two and three-fold locking systems. Another known system of the synchronization control for multiple setting devices may be application of a smart proportional regulator with electric fluently controlled gates or valves. The high cost, spatial exigency, low resistance against low temperatures and vibrations and consequently the lower reliability are the disadvantages of this solution.

The manual emergency setting of the hydraulic system disadvantage by means of independent manual pump is the high spatial exigency, higher complexity and lower readiness because of necessity to switch over the functions. The disadvantage of systems which applies the electric motor shaft revolving via crank and with mechanic drive box is its complexity and production exigency of the drive box and possibly dilating mechanic clutches as well.

The disadvantage of systems with setting force limiters used in design with common hydro-drive is the proper operability just in the limiting positions and the function in the course of full cylinders stroke is unreliable.

The nature of technical solution

To remove the imperfections of given known equipment in possible largest extent is the task of the technical solution.

This can be reached with hydraulic equipment with parallel connection of the hydraulic cylinders pursuant to the technical solution, in which there exists the main reverse pump and on the same shaft is assembled the auxiliary reverse pump, which is connected with hydraulic circuit of the main reverse pump via couple of one-way valves for the pressure delivery and via couple of one-way valves for intake for one thing via the throttling element with tank for hydraulic fluid, where the main and auxiliary reverse pump are connected via one-way intake valves.

The advantage of this arrangement is possibility of simple, prompt and operationally reliable emergency setting of the switch, or the crossing part of the turnout, by means of crank put just on the hydraulic drive electric motor shaft. The suitably selected parameters of the stated pumps and valves may secure the appropriate hydraulic reduction, rated fluid intake pressure and the suitable system efficiency under low revolutions of the crank as well -approximately 60 till 100 r.p.m. Another advantage of the mentioned solution it is the spatially undemanding built-up area, absence of the three-way valves and possibility of the whole system locking cylinders setting from the one single point with one person and within the real time.

With respect to the simple and operationally reliable synchronization of the hydraulic cylinders within the two, till three-fold locking devices it is advantageous, when in the hydraulic circuit of the main reverse pump are the hydraulic cylinders in the parallel connection via self-regulating flow valves with by-pass on the intake and output side of the cylinders.

For hydraulic cylinders synchronization of more locking devices it is advantageous, when the hydraulic cylinders are connected into hydraulic circuit of the main reverse pump via pulse controlled electric-magnetic valves. The pulse control is carried out by the control unit with the feedback utilization, which means the higher reliability, higher resistance against vibration and very good synchronization of single locking devices.

To secure the reliable restriction of the setting force in the hydraulic cylinders of single locking devices, to reach the easier way of the switch trailing by the railway vehicle and enable the liquid filtration by the central filtering bridge, the furnishing of the transfer valves into hydraulic cylinders pistons is essential.

List of drawing illustrations

The technical solution shall be clarified under the drawing utilization, where on the Fig. 1 it is depicted the hydraulic circuit with main reverse pump and with auxiliary reverse pump, at Fig. 2 we can see the hydraulic cylinders arrangement with transfer valves in pistons and their connection to the hydraulic circuit via self-acting flow regulating valves and on the Fig. 3 there is an alternative connection of hydraulic cylinders to the hydraulic circuit via pulse controlled electro-magnetic valves.

Examples of the technical solution

The locking device hydraulic equipment pursuant to Fig. 1 consists of the main reverse pump 1 and the auxiliary reverse pump 2 arranged on the mutual shaft 0 with electric motor 3. The main reverse pump 1 is the gear pump and it is designed with respect to the requirements of hydraulic circuit 17. The auxiliary reverse pump 2 has generally the lower output and it is advantageous as a gear pump as well. Into hydraulic circuit 17 of the main reverse pump 1 is the auxiliary reverse pump 2 connected via two output one-way valves 8 and via two intake one-way valves 9. The pressure regulation in the over-pressured circuit 18 is carried out by throttling element 6. The pressure regulation in the main circuit 17 is carried out by the safety transfer valves 10. The working liquid is coming into the main reverse pump 1 and into auxiliary reverse pump 2 sucked in always from couple of suction one-way valves 4 from vessel 5. The part of the main hydraulic circuit 17 is the reverse compressive filter 7. In the main hydraulic circuit 17 pursuant to arrangement in the Fig. 2 the hydraulic cylinders 11 of the closing system are connected to the main hydraulic circuit 17 in parallel connection via couple of self- acting regulating valves 14 of the flow with bypass. This connection is suitable for locking devices with three-fold hydraulic cylinders 11 at most. For locking systems with more hydraulic cylinders 11 it is suitable the hydraulic cylinders parallel type of connection 11 via electro-magnetic valves 15 pulse controlled electronic unit 16 pursuant to Fig. 3. At both variants are the controlling elements 14.15 built just on the hydraulic cylinders H. In case the arrangement is carried out pursuant to Fig. 2, then according to the Fig. 3 are the hydraulic cylinders H pistons 12 equipped with integrated transfer valves 13, which may be used with advance as a ball valves.

The hydraulic equipment for locking devices of the railway turnouts is based on the principle of hydraulic circuit 17 overflow of the main reverse pump 1 by the squeezed out volume of the working liquid from the auxiliary reverse pump 2. The overflow, comes always into actual suction, part of the hydraulic circuit 17 or to the main reverse pump 1 by means of suction via open appropriate discharge one-way valve 9. The discharge one-way valves 8 hold down the auxiliary reverse pump 2 suction just from the tank 5.

The actual overflow of the main reverse pump suction 1 for one thing prevents efficiency of the main reverse pump and moreover it prevents rupture of the working liquid column and increases the efficiency of the main reverse pump 1 (which is substantial) within the low revolutions of the manual operation by means of crank (not illustrated) inserted on the shaft 0 of the electric motor 3. The permanent overpressure in the overflow circuit 18 is secured by the throttling element 6, where the working liquid is flown back to the tank 5. As a throttling element the membrane may be applied, or the transfer valve as well.

The synchronous movement of pistons 12 of the hydraulic cylinders H according to the design pursuant to Fig. 2 is carried out by self-acting flow regulating valves 14 equipped with bypass of general design and just adjusted this way to be able to work within the most advanced field of regulating characterization with respect to the given flow, which is appointed by hydraulic cylinder H geometric volume and by the time period of its adjustment. This kind of regulation does not consist the feedback and operates just with using of the turnout switch rails self-regulation ability, which partly substitutes the feedback.

The synchronization of the piston movement 12 is reached in design pursuant to Fig. 3 by means of pulse controlled electro-magnetic valves 1JL which are in the primary state closed by the electric pulses coming from the control unit 16L With this design the piston position scanning by the piston position sensors 12 is necessary. This signal creates the feedback to carry out the appropriate regulating intervention.

The transfer valves 13 in pistons 12 of the hydraulic cylinders 11 are adjusted to the overflow pressure corresponding with necessary setting force of pistons 12, which enables the little bit higher pressure of the hydraulic liquid source to secure the proper activity of the self-acting regulation valves 10. This pressure is limited by the common safety transfer valves 13. The opening of the transfer valves 13 is carried out for instance the case occurs, when the partition penetrates between the switch rail and the stock rail of the turnout and the hydraulic liquid pressure on the piston side 12 is increased in front of the transfer valve 13. The transfer valves 13 also perform their function when the railway vehicle is trailing wrongly adjusted switch, when the working liquid pumping from the piston one side 12 to the opposite side is quickly carried out. In the same time the transfer valves 13 follow its filtration function, when the= electric motor 3 operates for a short time after the limiting position of the piston 12 is attained, when the increased pressure opens the transfer valves†3 and the fluid starts to flow and filtration in the reverse pressurized filter 7 is carried out.