When pressure or vacuum is applied to hydraulic cylinders, the cylinders either expand or retract in response to the force. (Travel measurement on hydraulic cylinders) The only things that can restrict the movement are the technical design of the cylinder and the length of the piston rod if it occurs. On the other hand, the pressure inside the cylinder is maintained even in the absence of either automatic or manual management. It is possible to do this on purpose, for instance, in order to maintain the same height for a load. The movement of a linear cylinder, on the other hand, can be made significantly more comfortable with the assistance of a route measurement.
Use of path Travel measurement on hydraulic cylinders
A sensory detection of the extended or retracted piston in a particular path is what the path measurement is all about. The terminal position of the piston is sent to a control unit through this mechanism, which subsequently has the ability to initiate any actions that are necessary. (Travel measurement on hydraulic cylinders) Measurement of distance is useful for a variety of applications, including to:
- Limitation of the extension path of the piston
- Repeatable movement along a defined path of the piston
- Triggering a chain of actions after reaching a defined distance
- Security features
The structure department has two possibilities for implementing a displacement measurement: either during the initial planning of the hydraulic system or as a subsequent extension. Anticipatory planning of hydraulic pistons with displacement measurement is significantly more straightforward and convenient than retrofitting.
Technical principles for displacement measurement
When a hydraulic linear motor is measured, the travel measurement (Travel measurement on hydraulic cylinders) is used to record the distance that the piston tip of the motor has traveled. In the past, relatively basic touch switches were utilized. These switches opened or closed an electrical circuit with the assistance of a pin. The problem of them, however, was that they only had a limited service life due to the wear and tear that was caused by mechanical wear.
This is the reason why non-contact sensors are the only ones that are utilized for hydraulic cylinders that have built-in end position detection available today. With that being said, mechanical systems are nonetheless frequently utilized in the present day for the purpose of subsequently implemented end position detection. These are primarily compatible with cables.
Advantages of built-in end position sensors when measuring distances
Almost every manufacturer of hydraulic cylinders provides an option for their linear motors that include either built-in end position sensing or travel measuring. In order to maintain the measurement’s repeatability and prevent wear and tear, magnetic or eddy current sensors are utilized. Optical sensors are not appropriate for this function because of the limited reliability they possess in situations that are frequently filthy. There is no requirement that the hydraulic system be installed in a particularly filthy location of any kind. Even the oil mist that escapes from the cylinder has the potential to render a picture sensor useless in a very short amount of time.
To function, the magnetic sensors make use of a powerful permanent magnet that is integrated inside the piston rod. This causes the signal to be triggered whenever it passes through the sensor. The signal is registered by the control unit, which has the ability to initiate any sequence of activities. As an example, this includes bringing the cylinder to a stop and retracting it, as well as activating additional actuators, signals, and orders. A comparable operation is carried out by eddy current sensors.
Their primary distinction is that they are able to function with magnetic fields that are not as powerful. The presence of an aluminum sleeve on the piston rod is all that is required to bring about the desired change in the value that is being measured by the sensor when using these sensors. On the other hand, induction sensors of superior quality are characterized by their utilization of two electromagnetic coils that, when brought into close proximity to one another, mutually induce a measuring current.
Price, service life, size, and precision are the primary areas in which these principles will differ from one another. One thing that distinguishes them from one another is the fact that they can be practically incorporated into the piston rod. This, however, is only allowed in the case of ex-works. There is no way to retrofit a hydraulic or pneumatic cylinder with an induction, eddy current, or magnetic sensor once it has already been installed.
Retrofittable distance measurement by cable sensors
Compared to integrated, non-contact path measuring sensors, draw-wire sensors are considered to be more fundamental from a technical standpoint. On the other hand, they are not as well suited for use in conditions that are very demanding. Draw-wire sensors are frequently used in the fields of construction trucks and other similar applications. The degree of personalization that they provide is rather considerable, and they are also able to handle temperature swings effectively. However, the daily maintenance procedure needs to incorporate their control in order to be effective.
This way you can measure travel hydraulic cylinder (Travel measurement on hydraulic cylinders)
