A hydraulic drive has a defect and the service personnel received the request to resolve this as soon as possible.
After the first assessment it is already clear that the problem possibly lies in the hydraulic control circuit of the drive.
But how to limit the defect or even to localize it directly?
Was it caused by the missing setpoint of the external control, does the valve have a sufficiently high power supply, is the control piston in the valve blocked or is there any problem with the mechanics system ? It is frequent the case that several people on site with different types of know-how are discussing about the technical problem but only presumption can be made about the cause of the problem.
Many questions come to light which at first instance can only be answered with difficulty.
With modern hydraulic valves with integrated electronics (On Board Electronics) the electric signal cable is directly connected to the valve, without further measurement sockets or optical feedback.
Consequently, the electrical engineer has no chance to check the electrical signals directly on the valve.
The hydraulic engineer cannot test the function of the valve on site as he cannot manipulate the required setpoint signal of the external control.
The mechanic can also not check system parts since nothing happens without valve function.
All that remains is to exchange suspicious components in the hope that you chose the right component.
Mostly, an exchanged hydraulic valve is not replaced when there is a failure and then it is send to the manufacturer for inspection at high costs.
That doesn’t have to be the case!
By looping the valve testing device VTB1-2X the service personnel has the following options:
- Test of supply voltage
- Switching of up to two shut-off valves (pressure release)
- Set required valve enable (24V)
- Check external valve setpoints (voltage or current)
- Input of a manually controlled, internal valve setpoint (voltage or current)
- Control of valve actual value (voltage or current)
- Input of a controlled setpoint profile (in %)
- Graphical trend recording of setpoint and actual value with the possibility of data storage to an external USB memory stick
Overview Data and technical functions:
- Monitored operating voltage: >21V DC .. <28V DC
- Monitored current operation of proportional valve
- Permissible ambient operating temperature: 0°C .. 40°C
- Protection class IP50 (dust-protected, no water protection)
- Weight: 2.35kg
- Resolution of the analog inputs and outputs: 12bit (+-10V; +-20mA)
- No signal delay times with function „loopthrough external setpoint“
- Voltage or current differential input for external valve setpoint.
- Polarity protection of the supply voltage.
- Short-circuit proof switching outputs A & B for 24V solenoid switches.
- Short-circuit proof analog outputs.
- Shock-resistant ABS plastic casing with guard rails.
- Supply voltage via valve supply 24V on the machine or ext. mains adapter.
- Safeguarding of the 24V supply voltage via changeable fuse.
- Standard signal assignment of device input connector and valve cable socket (6+PE).
- All required pre-settings via 7-inch touchscreen configurable.
- Switching function for different national languages.
- Structured clear menu navigation.
- Selectable help texts for each menu option.
- Functions that cannot be used and which are excluded by menu configurations and they are hidden graphically and textually.
- Optional drive of a switching shut-off valve or a switching way valve with a 24V solenoid or two 24V solenoids (2A current load per channel).
- Support of 10 possible analog valves setpoint signal types.
- Signal range for valve setpoint and actual value: +-10V ; +-20mA
- Mixed operations are possible (e. g. setpoint: +4..+12..+20mA; actual value-10..0..+10V)
- Additional, standardized valves setpoint display in the unit%.
- Internal valve setpoint set-up via rotary pulse generator with push-button function.
- Parametrizable, open loop oscillation profile for endurance test or bleeding function usable.
- Two-channels, graphical trend display with USB memory function for current valve setpoint and actual value.
- Dependent on the existing machine dynamics, all internal setpoint inputs can be operated via an adjustable ramp time.
Electrical pin assignment "6+PE" (according to EN 175201-804).
We also supply signal adapters for hydraulic valves with 11-pole(s) device connection.
Currently, 10 signal types for the valve setpoint configuration are available.
The possible signal types consist of three voltage and seven current signal types.
1. Voltage -10V .. 0V .. +10V with 0V for the hydraulic zero position
2. Voltage 0V .. +10V with 0V for the hydraulic zero position
3. Voltage 0V .. +5V .. +10V with +5V for the hydraulic zero position
4. Current +4mA .. +12mA ..+20mA with 12mA for the hydraulic zero position
5. Current +4mA .. +20mA with 4mA for the hydraulic zero position
6. Current 0mA .. +20mA with 0mA for the hydraulic zero position
7. Current 0mA .. +10mA with 0mA for the hydraulic zero position
8. Current -20mA .. 0mA .. +20mA with 0mA for the hydraulic zero position
9. Current -10mA .. 0mA .. +10mA with 0mA for the hydraulic zero position
10. Current -15mA .. 0mA .. +15mA with 0mA for the hydraulic zero position
The following valve types can be tested with the valve testing device VTB1-2X
- Proportional pressure control valves:
- Proportional way valves:
DHZE-A DHZO-T* DLHZO-T*
DKZE-A DKZOR-T* DLKZOR-T*
- Proportional integrated valves: