NTC-11.94 “Hydraulic equipment with electric proportional control”

• proportional electromagnet;
• discharge hydraulic valve with proportional control;
• hydraulic distributor with proportional control;
• reducing valve with proportional control;
• three-port flow regulator with proportional control.

The stand includes a hydroelectric station, which is made in the form of a separate module. The hydraulic station consists of a hydraulic tank, a gear pump NSh10-3L, driven into rotation from an asynchronous three-phase electric motor. A filter and a pressure hydraulic valve are installed in the pressure line of the pump. The stand has a frame structure with a table and two panels: hydraulic and electric. A two-line flow regulator and research objects – four devices with electric proportional control (pressure valve, hydraulic valve, pressure reducing valve and three-line flow regulator) are installed on the table. In addition to the listed devices, a proportional magnet is installed on the table.

On the hydraulic panel are installed:

• adjustable throttle;
• flow meter;
• thermometer;
• three manometers;
• two sockets for connection to manometers.

The stand has a non-rigid (variable) structure. Structuring the scheme is carried out using elastic pipelines with quick disconnect connections (BRS). Each BRS consists of two parts: half couplings with a check valve and half couplings with a lock. The stand includes a set of flexible pipelines. Half-couplings with clamps are installed at the ends of the pipelines. Two pipelines are simple, that is, they do not have branches, and the remaining two have branches (of smaller diameter). Branches are used to connect to a pressure gauge. A tee with a branch must be installed on the side of the device for which (at the inlet or outlet) it is necessary to measure the pressure, which will improve the accuracy of determining the characteristics of the devices.

On the electrical panel of the stand, a hydraulic circuit diagram of the stand is shown, as well as electrical control devices for the stand and its subsystems and digital registration of parameters. By means of the “NETWORK” switch, the stand power is turned on. The buttons SB1 and SB2 are used to control the pump of the hydraulic station. The voltage level supplied to the proportional magnet is set using the regulator (voltage regulation is possible within 0 … 24 V). The electromagnet power device is turned on using the toggle switch. The switch SA1 provides connection to the power source of the electromagnet (coil) of the corresponding device. The four devices studied at the stand contain five electromagnets with proportional control. Each of these devices has one electromagnet installed, with the exception of the control valve, which contains two electromagnets. In individual tests of the proportional magnet, switch SA1 should be set to “K” (coil). The signal supplied to the electromagnet is recorded using digital indicators – “Voltage, V” and “Current, A”.
To register the time passing through the flowmeter of a given volume of liquid (for subsequent determination of flow), an electronic stopwatch is installed on the stand. The results of measuring the force at the anchor of a magnet with electric proportional control during its separate tests are displayed in Newtons on a digital indicator – “Force, N”.

In addition to four hydraulic devices with electric proportional control, the stand provides for research of an individual electromagnet. This electromagnet is mounted on a table. The magnet armature interacts with a gauge beam through the movable rod of the dial gauge, designed to measure the force generated by the magnet. In the transmission mechanism, a special emphasis is installed on the thread between the indicator and the strain gauge. When screwing the stop and the presence of voltage on the coil, the core (anchor) of the magnet extends. This allows for various positions of the armature to determine the force provided by the magnet, and to determine its main characteristic.

A set of methodological and technical documentation intended for the teaching staff is supplied with the stand.