About the characteristics, benefits and areas of use of the security edge
The "Machine Directive" points out that for dangerous machines to be put into operation, comprehensive safety measures must be taken to protect the people who use these machines.
One of the measures is to protect the automatic drive device that has a significant risk of cutting blade and crushing damage.
In order to prevent the risk of cutting edges and breakage, safety-sensitive touch edges can be used.
For example, some typical applications, machine protection, lifting platform, theater stage, etc. When you trigger the safety edge, the power will be cut off immediately. Before CYNDAR launched the safety edge, there were either electric operating devices based on the N/O principle (when the safety edge was touched, two conductive bands or layers would be connected), or alternative standard photoelectric devices System (beam is interrupted). Devices like this operate via signals, which need to be converted and processed via the control unit.
CYNDAR contact chain design and operation mode
Machines and equipment with dangerous movements must be equipped with emergency stop devices. This device is monitored by an appropriate safety relay unit.
Our safety contacts are connected in series with a mechanical N/C switch, which is established in the form of a contact chain. Conductive contact rollers and insulating adjustment parts (wedge rollers) are alternately arranged on the expansion line. Through the pretension, the contact rollers will squeeze together to make the current flow.
The impact force will cause the wedge-shaped adjustment component to move and disconnect at least one pair of contact rollers in the safety contact edge, so that the current will be interrupted. Since the current interruption generates a signal, there is no need to perform output signal conversion, and the circuit interruption signal is direct
Available. The interrupt signal is transmitted to the safety relay control and directly received by the emergency stop button. Good switching characteristics The sensor part of the safety edge is located directly behind the rubber. The connection interruption is not caused by the deflection of the contact chain, but by the conversion of external radial forces into axial forces. Even with a small trigger force and a short displacement, this force can trigger the shutdown function. The remaining height of the rubber can be used in overtravel. Especially with regard to injury prevention, large overtravel safety and sensitive touch edges are extremely important.
Due to the rotationally symmetrical design of the contact chain, theoretically our contact edge can be operated in any direction, that is to say, its sensitive range can cover 360°.
Benefits for users
Since the contact chain is electromechanically interrupted by the contacts, a special control unit is not required, and the interrupted signal can be used immediately. In addition to saving costs, no expensive connection and wiring operations are required.
No need for an additional control unit to win treasure on a crowded control panel
Expensive space. Of course, another non-existent device cannot go wrong. The use of disconnect contacts guarantees a higher level of safety.
The contact chain safety edge conforms to DIN ISO category 3 in the corresponding design configuration
EN 13849-1-including the sensor part. For our system, dual-channel or more design is not necessary, the failure mode analysis of the German laboratory BG
It shows that: a single failure will not lead to the loss of the safety function, which means that the establishment of a simple structure system is allowed.
When a single error occurs, the system will immediately change to a safe state: shut down. If the safety edge and the end cap are not perfectly bonded, or the seal becomes poor because the glue becomes brittle, any insulators such as dust and dirt that may enter will not cause the loss of the safety function.
Define the field of use for each application
For any electrical component, the key feature is usually sealing, and of course the same is true for the safety edge. Humidity or water intrusion may cause damage to the components. The key to safe edge sealing is that the interface between the rubber and the end cap is usually glued together.
Indoors, there is no problem in using a device that uses glue to glue the end caps. Here, the safety edge is usually exposed to harsh environments, such as oil, coolant, etc., but water rarely occurs in large amounts. In addition, high concentrations of extreme temperature, ozone, and ultraviolet radiation are rarely found.
Outdoors, the opposite is true. Under such conditions, the glue of the end cap will become brittle over time, which will affect the tightness.
CYNDAR provides different materials and sealing technologies for indoor and outdoor use. Our outdoor safety edge is a vulcanized bottom cover, so water is not a problem.