Cylinder; Servo Solenoid Valve; Valve Amplifier; Shutoff Valve - Siemens Sinumerik 840D Series Function Manual

02.99
10.03
1.3.2

Cylinder

Construction
Quality criteria
1.3.3

Servo solenoid valve

Task
Function
1.3.4

Valve amplifier

1.3.5

Shutoff valve

1.3.6

Position measuring system

Task
 Siemens AG, 2003. All rights reserved
SINUMERIK 840D/SIMODRIVE 611 digital, HLA Module (FBHLA) - 10.03 Edition
1.3 Structure of an electro-hydraulically-controlled drive axis
The cylinder represents the simplest form of linear motor and can be integrated
easily into the machine guide. The cylinder normally has a piston rod at one
end.
The following are critical quality criteria:
S
The surface quality of barrel and piston rod and
S
The seals and guides (low-friction, servo quality...).
This is the final control element in the closed control loop and forms the electro-
hydraulic converter.
The valve steplessly converts electrical signals into a hydraulic flow.
Its quality is defined by static and dynamic parameters, such as
S
Zero overlap
S
Hysteresis
S
Limit frequency, etc.
This circuit contains the power electronics for the solenoid in the servo solenoid
valve which adjusts the valve spool position.
The position controller in the valve amplifier (on-board electronics - OBE) con-
trols the position of the valve spool proportionally to the output value
(U=0..."10 V).
Shut-off valves are used to add safety functions to a valve control with servo
solenoid valve. Shut-off valves can prevent uncontrolled motion of the cylinder.
The position measuring system supplies the actual value for the position of the
moving machine element.
1 General
1-19