Edited by Mary C. Gannon,
Senior Associate Editor
Position transducers make automation with penumatics even more effective by serving as reprogrammable limit and proximity switches. Equipped with an expanded range of functions, the new series SF1 cylinder sensors from Bosch Rexroth, Lexington, Ky., substantially reduce installation and maintenance costs during operation while making position sensing even more user-friendly. All of the sensor’s components are securely joined to the cylinder.
|Designed for use on miniature pneumatic actuators, the SF1 series sensor provides position sensing control in either analog or digital versions. |
The sensor was developed to give machine builders a choice for pneumatic actuator position control and monitoring. It is available for either analog or digital cylinder condition monitoring, for specific position monitoring, or to measure the entire stroke. The sensor can be used on cylinders in many applications and machines including packaging, material handling, and general automation.
Going small for sensing
Currently the SF1 sensor is available on Rexroth series OCT cylinders, a line of pneumatic mini cylinders with strokes from 65 to 500 mm that is certified to ISO 6432. Also known as the Octagon cylinder because of its octagon shape piston, it features rotating or non-rotating rods. The SF1 is integrated to make the cylinder sensor a functional component of the pneumatic actuator, rather than an accessory. It is built into the cylinder profile with an integrated foil sensor, reducing the number of moving parts and eliminating the need for separate installation and adjustment of the sensor on the cylinder. This also makes it very sturdy and protected against external mechanical influences.
Standard cylinders are also available or a custom combination of bore/stroke and options can be designed using Bosch Rexroth’s online configurator for cylinders and valve systems.
Set switching points easily
The analog version of the SF1 enables analog depiction of the entire cylinder stroke, using an operating voltage of 15 to 30 V. The digital option version supports two or four switching points, using simple “select” and “set” buttons on the attached electronics. Digital switching point setting is done through a simple teach-in procedure that makes setup and operation easy compared to laborious mechanical adjustment of the cylinder switches, and any number of intermediate positions can be recorded.
The easy-to-use teach-in procedure does away with manual setting, reducing the number of moving parts and making installation quicker and easier. A further step towards condition monitoring is the option of monitoring the entire stroke using an analog output signal. The sensors’ ability to make position inquiries using digital switching points or through analog methods along the entire stroke is the latest stage in development from a pure accessory part to an integral functional component of the pneumatic actuator.
The sensing, setting, and adjustment of switching points for the cylinder is possible using a handheld device or PLC without having to reach into the machine. In addition, the sensor can be integrated into a control concept to allow the pneumatic stroke to be monitored at any time.
The SF1 is rated at IP50 protection and can be used in ambient temperature environments from 32° F to 122°F. Repeatability is ± 0.1 mm while the accuracy is stroke/1000.
Visit www.boschrexroth-us.com or call (800) 739-7684 for more information.