There are two types of commonly used high-performance hydraulic valves:
1. Servo characteristic proportional valve
Also known as high frequency response proportional valve or proportional servo valve. This kind of valve is used more. The ±10V control signal must be selected when selecting the model (4-20mA control signal cannot be selected).
2. Servo valve (current drive)
This kind of valve has been called a servo valve since it was created, and it needs a current input to drive, for example, a drive current of ±50mA. When the RMC controller is used in conjunction with the servo valve, a voltage-to-current mode is required
Piece. The VC2124 module produced by the American DELTA company can convert two ±10V signals into two ±100mA current-driven servo valves.
Servo characteristic proportional valve
In order to achieve excellent performance, convenient debugging and reliable equipment, the United States DELTA recommends the use of zero-opening linear valves and valves with integrated circuit boards.
RMC75E and RMC150E can support non-linear valves (with an inflection point), but additional parameter settings are required for debugging. Linear valves are easier to use.
Linear valve:
The linearity of the valve means that the relationship between the flow rate and the control command is linear (at least linear within ±8V) (see the figure below):
If the valve selection data uses terms such as bend, inflection point, gradual change and other terms to describe the characteristics of the valve, it indicates that the characteristics of the valve are non-linear, and should be avoided as far as possible.
Zero opening valve:
This refers to the mechanical characteristics of the valve port so that as long as voltage is applied to the valve, the hydraulic medium starts to flow immediately.
The circuit board is integrated in the valve:
Users of this valve do not have to worry about the installation and wiring of the circuit board. Generally, for a good valve, the user does not need to make any adjustments to the circuit board part.
important hint:
Generally speaking, it is not worth the gain to select valves with overlapping valve ports or called dead zones and nonlinear valves for closed-loop control. It is necessary to avoid them when selecting models. Recommended servo characteristic proportional valves, the following are several valves that have been successfully used with the American DELTA RMC controller. Many valves provide ±10V or 4-20mA input. Be sure to choose a valve with a ±10V control signal. Recommended servo characteristic proportional valves, the following are several valves that have been successfully used with the American DELTA RMC controller. Many valves provide ±10V or 4-20mA input. Be sure to choose a valve with a ±10V control signal.
Bosch Rexroth
4WRPEH: Specifications NG6 and 10. The valve must be specified with a linear option.
Parker
D1FP and D1FP*S: Specifications NG6 and D04. Be sure to select the ±10V control signal option.
Atos
DLHZO and DLKZOR: Specifications NG6 and 10. Be sure to choose a linear valve. DELTA also recommends to choose the type with TE option that is integrated circuit board into the valve body.