AUTOMATION AND PROCESS CONTROL
H118D - Modular Oil Power Hydraulic Trainer
1. General
Didacta’s H118D is a modular system specially designed to test out the techniques for the transfer of fluid power and electrohydraulic control techniques.
It is suitable for technical and professional training at different levels.
It consists of a trolley mounted structure with a hydraulic power supply unit and two panels, one for the basic oil power
components and one for On/Off and proportional electrical control.
The two panels are functionally independent, but can be coupled so as to form a double-faced structure, which is installed on
the trolley mounted frame.
The panels can be used independently, using an external hydraulic power supply with suitable characteristics.
The trainer can be easily interfaced with Didacta’s CP30D PLC or another programmable logic controller available to the
user in order to program complex operating cycles.
The trainer is supplied with an exhaustive manual, including a technical description of all the components, operating and
maintenance instructions and many exercises.
2. Composition
Basic assembly

Panel bearing trolley mounted structure, complete with hydraulic power supply unit (Code 936221);

H118/1D panel for basic oil power tests (Code 936210);

H118/2D panel for On/Off electrical control tests (Code 936211).
Options available for panel H118/2D

Proportional valve with electronic control (Code 936230);

Slow/fast function hydraulic valve (Code 936231);
DIDACTA Italia S.r.l. - Strada del Cascinotto, 139/30 - 10156 Torino - Italy
Tel. +39 011 2731708 - Fax +39 011 2733088 - http://www.didacta.it - E-mail: info@didacta.it


Pressure relief valve for use without the hydraulic control unit (Code 936232);
Additional hydraulic power supply unit enabling the two panels, H118/1D and H118/2D, to be used simultaneously (Code
936234).
PLC in educational version (option)

CP30D/C – PLC with RS232 output for PC (Code 971351);

Remote programming unit for CP30D/C (Code 971353);

CMOS-RAM memory cartridge with battery for CP30D/C (Code 971354);

CP30D/C programming software for H118D (Code 917003).
The options available for the CP30D/C PLC are described in a separate data sheet.
3. Description
Panel bearing trolley mounted structure complete with hydraulic power supply unit (Code 936221)
The structure consists of a tubular steel frame treated with epoxy paint, a fibreglass reinforced plastic tank for possible oil
leaks, a bottom tray accommodating the hydraulic power supply unit, a tool drawer.
The hydraulic power supply unit is supplied with a (24 l) oil reservoir and a gear pump designed to ensure a flow-rate of 9
l/min at a max. pressure of 30 bar.
H118/1D panel for basic oil power tests (Code 936210)
General characteristics
The panel makes it possible to test basic oil power technologies. The industrial type components are mounted on bases
conforming to ISO standards, with fast connectors at front.
The panel can be used to perform functional tests, and for the calibration and adjustment of each component.
Flow control and divert components

3 cut-off valves

1 pressure reducing valve

1 compensated flow control valve

1 2/2 distributor, lever operated

1 3/2 distributor, lever operated

1 4/2 distributor, lever operated

1 check valve

1 hydraulically controlled check valve

1 diaphragm type accumulator

1 fluid distribution block

1 fluid discharge block
Actuators

1 double-acting cylinder
Measuring instruments

2 pressure gauges, 0 - 60 bar

1 flow-meter, direct reading 2-15 l/min
Accessories

Set of hoses complete with fast connectors

Complete set of pipes and unions for pressure drop detection
Fig. 1 - H118/1D panel
H118/2D panel to test On/Off electrical control techniques (Code 936211)
General characteristics
The panel is fitted with components for technical and professional training on On/Off control oil power circuits.
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The options available make it possible to extend the tests to proportional control.
The panel uses modular type components.
This technology is the same as is used in the construction of industrial oil powered automation machinery (numerical control
machines, transfers, pick & place robots, etc.).
Each module includes a closed centre solenoid valve and a certain number of valves with flow-rate and pressure adjustment
and control functions.
On the output side of each module we find the connections to link the module front to the actuators by means of hoses.
The unit can be started only by means of a key-operated selector.
The pressurised fluid will reach the actuator only if the relative solenoid valve is commutated. In this manner the exercise can
be carried out in maximum safety conditions.
The compressed air supply and discharge lines are common to all modules.
All circuits are depicted in a silk-screen printed scheme to the side of the panel.
Flow control and divert components

Module 1: pressure switch, 4/2 solenoid valve, check valve;

Module 2: 4/3 solenoid valve, compensated single-acting flow control valve, 2/4 solenoid valve;

Module 3: 4/3 solenoid valve, single-acting flow control valve, pressure relief valve;

Module 4: 4/3 distributor, 2 hydraulically controlled check valves;

Module 5: 4/3 solenoid valve, 2 single-acting flow control valves;

Module 6: 4/3 solenoid valve, 4/2 solenoid valve;

Module 7: 4/3 solenoid valve, pressure relief valve;

Module 8: 3/2 solenoid valve, sequence valve;
Optional flow control and divert components

Module 9: proportional valve with electronic control (Code 936230);

Module 10: hydraulic valve with fast/slow function (Code 936231).
Electrical control panel components

Automatic switch

220 V AC / 24V AC transformer.

24 V AC / 24 V DC rectifier.

Control relay to assemble automation devices.

Circuit commutation selectors, module pre-setting.

Maximum pressure switch.

Signal test connectors.

Relay type exchange contacts.

Solenoid valve “On” telltales.

Silk-screen printed aluminium panel.
Actuators

1 single-acting cylinder with 2 limit switches.

1 double-acting cylinder with 3 limit switches.

1 orbital hydraulic motor with digital rpm measuring system.
Measuring instruments

3 pressure gauges, 0 - 60 bar

1 flow-meter, direct reading 2-15 l/min
Accessories

Set of hoses complete with fast connectors.
Fig. 2 - H118/2D panel
4. Experiments
H118/1D panel
Theoretical exercises

Hydraulic physical quantities and measuring unit.

Physical principles of hydrostatics.

Motion of fluids.

Head losses in pipe lines.

Valve and distributor characteristics.

Properties of fluids.

Characteristics of hydraulic power supply unit.

Pressure and flow-rate measuring instruments.

Accumulators.
Practical exercises
 Pressurisation and determination of Q=f (p) curve on hydraulic pump.
 Pressure measurements and functionality test on direct control pressure reducing valve.
 Functionality tests on 2-way, 3-way, 4-way, 2-position, lever operated hydraulic distributors.
 Functionality tests on single-acting valves and hydraulically controlled check valves.
 Flow-rate and pressure drop measurements on compensated flow control valves.
 Flow-rate and pressure drop measurements on flow limiting valve.
 Measurement of pressure drops in straight pipe lines and elbow fittings.
 Accumulator circuit with fluid charging and discharging in cylinder and tank. Measurement of pressure and flow-rate.
 Stick-slip effect in double-acting cylinder with load applied to the stem.
 Adjustment of flow-rate at output of double-acting cylinder.
 Load applied to the stem.
 Elimination of stick-slip effect.
H118/2D panel
Theoretical exercises
 Characteristics of the cylinders.
 Characteristics of hydraulic motors.
 Characteristics of hydraulic pumps absolute intake pressure and pump vacuum level above free surface of tank.
 Absolute intake pressure and overpressure with pump at bottom of tank.
 Intake height of pump.
 Project elements of a hydraulic circuit.
 Cycle diagram.
 Functional wiring diagrams.
 GRAFCET method for sequence cycle.
 Open and closed circuit.
 Basic programs and management of I/O electric controls with PLC.
 Characteristics of proportional valves.
 Application circuits with proportional valves.
Practical exercises
Module 1
 Setting pump on discharge by means of pressure switch and solenoid valve.
Module 2
 Operation of double-acting cylinder with solenoid valves under commutation. Fast approach, slow operation controlled by
pressure and thermally compensated valve.
 Solenoid commutation with automatic relay control and limit switches.
 Measurement of pressure and flow-rate.
 Determination of theoretical forces applied to the piston.
Module 2

Operation of hydraulic motor with compensated flow adjustment valve. Speed adjusted in one direction.

Reversal of direction of stroke.

Measurement of rotation speed with magnetic proximity sensor and digital measuring instrument.

Measurement of flow-rate.

Reading and interpreting the characteristics of the motor given in the diagram.

Theoretical calculation of motor torque and power.
Module 3
 Operation of double-acting cylinder with solenoid valve, flow limiting valve and pressure relief valve.
 Commutation of set pressure and adjustment of forward stroke speed.
 Measurement of pressure and flow-rate.
 Commutation of solenoids by means of a selector.
 Determination of theoretical forces applied to the piston.
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Module 4
 Operation of double-acting cylinder with distributor and hydraulically controlled check valves.
 Forward stroke and return by inching with piston position locking in either direction.
Module 5
 Operation of double-acting cylinder by means of solenoid valve and flow limiting valves.
 Adjustment of speed during piston forward stroke and return.
 Solenoid commutation in automatic mode with relays and limit switches.
 Measurement of flow-rate and determination of speed.
 Operation of single-acting cylinder by means of solenoid valve. Solenoid commutation by means of selector.
Module 6
 Operation of double-acting cylinder by means of solenoid valves under commutation.
 Automatic change-over from regenerated to normal during forward stroke.
 Return to normal speed.
 Solenoid commutation by means of relays and limit switches.
 Operation of double-acting cylinder with fast/slow hydraulic module during forward stroke.
 Slow speed adjustment.
 Fast return.
 Measurement of flow-rate and pressure.
 Operation in sequence between double-acting cylinder and hydraulic motor.
Module 7
 Hydraulic balancing by means of double-acting cylinder with pressure relief valve and solenoid valve.
 Measurement of controlled pressure and analysis of balancing forces acting on the piston.
Module 8
 Operation in sequence between double-acting cylinder and single-acting cylinder
 Measurement of pressures.
 Commutation of relay solenoids.
Module 9 - Option
 Operation of double-acting cylinder with electronically controlled proportional valve.
 Continuous speed adjustment.
 Setting the acceleration and deceleration ramp.
 Controlling the direction of flow.
 Measurement of pressure and flow-rate.
 Measurement of current in solenoids and plotting the Q = f (i) curve.
 Operation of actuators (single-acting cylinder, double-acting cylinder, hydraulic motor) with simulation of machine tool
circuits.
 Plotting the cycle diagram.
 Interpreting the functional wiring diagram.
Module 10 - Option
 Operation of double-acting cylinder with slow-fast hydraulic module and fast return.
 Measurement of pressures and flow-rates.
 Analysis of fast/slow valve operation.
5. Required Services



Single-phase 220V AC 50/60 Hz electrical power supply.
Low viscosity 3-4°E hydraulic oil (20 l supplied as standard with the trainer).
Hydraulic circuit to be supplied with ca 9 l/min at a max. pressure of 30 bar, if the trolley mounted structure with the
hydraulic power supply unit is not purchased.
6. Weights and dimension
Trolley mounted structure with H118/1D and H118/2D panels

Dimensions: 1200 x 1000 x 1600 h mm.

Net weight: 400 kg.

Gross weight: 610 kg.
Cod. R00161/E 0813Ed. 01 Rev. 03
In any time and without notice, Didacta Italia can carry out any appropriate modification on the product details, always
maintaining their main features, according to the designing and teaching necessity.
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