Valves
High dynamics and extremely short response times combined with optimum control characteristics are attained when incorporating Voith valves into your hydraulic system.
The compact valve design simplifies the integration into the machine or plant. In addition to our directional control valve, flow control valve and pressure valve range, Voith also offers sandwich plate valves, servo valves, as well as special valves for cooling and lubrication applications in machine tools.
Benefits
- Outstanding dynamic behavior
- High productivity
- Low operating costs
- High precision
- Easy integration
Hydraulic valves
Directional control valves
Extremely fast switching times combined with a very compact design, the Voith directional control valves belong to the solenoid valve product family. These valves achieve a switching time of less than 20 ms, without a booster. Furthermore, when installed with a booster, a switching time of less than 10 ms can be attained.
A potential space saving of up to 30 percent can be achieved when installing a double-acting solenoid, 4/3 Voith directional control valve. This space saving potential is based on a comparison of what is commercially available on the market from alternative suppliers.
The directional control valves are particularly well suited to hydraulic systems with short response times. The valves can be switched in real time virtually, facilitating an efficient and safe actuator cycle design. Short process times and high process reliability can be achieved in your system when installing Voith directional control valves.
Application fields
- Hydraulic power packs and hydraulic systems
- Machine tools
- General mechanical engineering
- Presses
Technical data
| Nominal sizes | NG 4, NG 6, NG 10, NG 25 |
| Standard designs | 4/2, 4/3 |
| Switching times (switching on and off) |
|
| Maximum operating pressure | 315 bar |
| Maximum volume flow | Up to 450 l/min |
| Designs |
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| Ports | As per ISO 4401 |
| Switch position monitoring | Optional |
| Operating voltages |
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| Protection class | IP 65 |
Advantages over proportional or servo valves
Hydraulic system designers often use servo valves or proportional valves as switching valves to achieve fast switching times in highly dynamic hydraulic systems. In these cases, you should consider using Voith directional control valves. They offer a whole range of advantages:
- Up to 50 percent lower procurement costs
- Less commissioning effort: no controller setting
- Lower oil purity required: less filtration effort and no pressure filter circuits
- Greater protection against malfunctions
- Up to 50 percent less installation space needed
- Reduced wiring effort
Flow control valves
In order to set volume flow precisely and repeatedly down to less than 10 cm3/min, which equates to roughly a flow rate of 3 drops per second, Voith flow control valves are recommended. They control the volume flow independently of the differential hydraulic fluid pressure and viscosity.
These flow control valves are ideally suited for hydraulic systems with controlled actuators that perform slow, precise movements. The values are set either with high sensitivity using a scaled hand wheel or by remote control, using a stepper motor with an analog or digital set-point signal. High process quality is consistent and is made possible with the installed actuator that moves uniformly.
Application fields
- Hydraulic systems with actuators that perform slow and precise movements without position control
- Feed control system in, for example, band saw systems
- Stroke control systems
Technical data
| Nominal sizes | NG 6 |
| Design | Two-way flow control valve |
| Volume flows | 10 to 20 000 cm3/min |
| Operating pressure | Up to 250 bar |
| Adjustment methods |
|
| Ports | As per ISO 4401 |
| Reproducibility | ± 2.5 percent |
Pressure valves
Operational reliability of your hydraulic system can be improved when using Voith pressure control valves. The valves limit or control the pressure within the hydraulic system. Alternatively, they can switch volume flows as a function of signal pressures. Four types of pressure valves are available:
- Pressure relief valves
- Pressure-reducing valves
- Check valves
- Accumulator charging valves
Application fields
- Hydraulic power packs and hydraulic systems
- Machine tools
- General mechanical engineering
- Accumulator charging units and accumulator charging circuits
Technical data
Pressure relief valves, pressure-reducing valves and check valves
| Nominal sizes | NG 4, NG 6 |
| Maximum operating pressure | Up to 315 bar |
| Maximum volume flow | Up to 30 l/min |
| Pressure ranges | 3 to 30, 5 to 60, 10 to 150 or 20 to 250 bar |
| Adjustment methods |
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| Designs |
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Accumulator charging valves
| Maximum operating pressure | Up to 315 bar |
| Maximum volume flow | Up to 180 l/min |
| Pressure ranges | 20 to 60, 45 to 80, 80 to 120, 120 to 175, 175 to 250 or 250 to 315 bar |
| Switching hysteresis | 5, 10, 15 or 20 percent |
| Adjustment methods |
|
Sandwich plate valves
Up to 50 percent installation space savings can be achieved by installing Voith hydraulic systems, as they require no pipe or hose connections. The building of compact, highly functional but still cost-effective hydraulic systems is made easy with Voith sandwich plate valves. The dynamic behavior of the system is further improved by concise control channels and the resulting short oil columns. The following sandwich plate valves are available:
- Pressure relief valves
- Pressure-reducing valves
- Check valves
Application fields
- Hydraulic power packs and hydraulic systems
- Machine tools
- General mechanical engineering
Technical data
| Nominal sizes | NG 4, NG 6, NG 10 |
| Maximum operating pressure | Up to 315 bar |
| Maximum volume flow | Up to 150 l/min |
| Pressure ranges | 3 to 30, 5 to 60, 10 to 150 or 20 to 250 bar |
| Adjustment methods |
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| Design | Sandwich plate valve with ISO 4401 ports |
Servo valves
Freely programmable, highly dynamic and with maximum process reliability, Voith servo valves (electro-hydraulic amplifiers) ensure that short-stroke actuator movements are carried out flawlessly. The current actuator position is fed back using a direct mechanical linkage and consequently in real time.
Benefit from high-quality parts and a long service life when equipping your machines with our servo valves. When designing position control circuits, the actuator position is usually fed back using electrical signals. The controller signal conversion and processing act as the limiting factors, thus ensuring position accuracy and the dynamic behavior of the control system.
Application fields
- Machines with highly dynamic, short stroke actuator movements
- Punching machines
- Presses
- Shearing machines
- Cutting machines
- Stamping machines
Technical data
| Volume flow | Up to 1 500 l/min |
| Operating pressure | 280 bar maximum |
| Settling time | 5 to 10 ms typically |
| 100% control time | 10 to 15 ms typically |
| Control | Using HS4 electronic control (RS-232, CAN, Profibus, Ethernet, USB) |
| Methods of mechanical position feedback |
|
Type SVIZ servo valve includes a gear rack to mechanically feed the current actuator position back
The stepper or servo motor specifies the position setpoint and actuates a nut-shaft drive that moves the individual valve pistons. The valve pistons open the valve and the actuator moves. The gear rack is linked to the actuator and feeds the actual position back to the valve piston actuation system directly using the pinion (mechanical feedback). As soon as the actuator has reached the programmed position, the pinion returns the valve piston to its initial position and the valve closes again.
| 1 Stepper or servo motor |
| 2 Actuator |
| 3 Nut-shaft drive |
| 4 Gear rack |
| 5 Pinion |
| 6 Valve piston |
| 7 Valve piston actuation system |
Valves for cooling and lubrication applications
Directional control valves and mounting plates
Utilizing a small amount of space yet providing the largest number of possible variations, our directional control valves and modular attachment plates are ideal for lubrication and cooling applications. Additional benefits include: fast machine assembly, upgrade/modernization possibilities as well as the fact that the product is ideally suited for retrofit projects.
The standard version with a ceramic ball ensures clean flow channels in the valve, preventing deposits and guaranteeing high wear resistance. For pilot control, the existing energy source on the machine is used and only low electrical circuit power is required.
| Design | Seat valve |
| Type of operation | Pneumatic, electrically switched |
| Type of attachment | 4 x M5 x 110 ISO 4762, 10.9 |
| Line connection | Mounting plate |
| Installation position | any |
| Ambient temperature | +10 to +50 °C |
| Mass valve | < 1 kg |
Benefits
- Integrated check function
- Flange construction and expandable controls
- Longitudinal and cross-linking can be extended, as required
- Different or equal pressure ranges
- Retrofit within existing plants
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