DE3619723A1 - Additional controller, having contacts, for safety circuits - Google Patents

Abstract

The invention relates to an additional controller, having contacts, for safety circuits, especially for monitoring electrical and electronic equipment. The additional controller, which has contacts, consists of a functional circuit to which in each case two auxiliary contactors or equivalent relays are allocated for each machine movement to be monitored, whose normally-open contacts, which are connected in series, have a redundant safety behaviour and act directly on the load circuit or circuits with a function which is relevant to safety. A defect monitoring circuit checks the opening and closing function of the auxiliary contactors or equivalent relays by means of dynamic defect simulation, during each connection of the control voltage.

Description

The invention relates to a contact Additional control for safety circuits in particular for monitoring safety-relevant Functional areas of electrical and electronic Resources.

To avoid dangerous conditions for people and machine in the event of a fault electrical and electronic Equipment is a special security measure hold true.

One of these measures are higher-level locking circuits with switchgear with contacts like auxiliary contactors or equivalent relays. The activation such safety circuits are carried out by corresponding command devices, such as emergency stop command device or position switch for safety shutdown of mechanical movements, especially linear ones Machine movements. The downstream of the command devices Lock control worked so far in a simple circuit structure such. B. with a Auxiliary contactor.

According to DIN VDE 0113 Part 1, in future, such Safety circuits the use of fault-monitoring Auxiliary contactor combinations are required such that if a contactor fails in the safety chain at least a second auxiliary contactor Shutdown of the safety-relevant circuits takes over.  

Self-monitoring of the safety chain is also necessary prescribed when switching on the control voltage, d. that is, after switching on the control voltage NO contact function of each contactor in the Safety chain to be checked.

The object of the invention is to meet the requirements according to DIN VDE 0113 part 1, safe and economical with circuitry simple means by use available and standardized switchgear, to be fulfilled and thus redundant safety behavior the security chain and self-monitoring the entire interlock circuit in the contact Additional control for safety circuits to reach.

According to the invention, this object is achieved by that a contact-based additional control from a Functional circuit and a fault monitoring circuit exists, with the function group for each to be monitored Machine movement two auxiliary contactors each equivalent relays are assigned, their normally open contacts connected in series a redundant safety behavior have and directly on the or the load circuits with safety-relevant function and indirectly by feedback on the electrical inputs and electronic equipment, and that the fault monitoring circuit has the normally closed function any contactor or contactor The relay of the additional circuit with contacts is monitored, by the control voltage or the emergency stop potential, the function of the contacts Additional control through dynamic error simulation is checked.  

Furthermore, according to the invention it is important that the contact-based additional control the emergency stop Safety circuit or other safety circuits added.

An advantageous development of the invention is that in the event of a fault, one of the auxiliary contactors in the contact Additional control only for this auxiliary contactor associated functional circuit interrupted becomes.

The fault-monitored circuit structure with contacts Switching devices, such as auxiliary contactors, are required at least two auxiliary contactors, their contacts in series enable the safety circuit or lock. Relating to electronic equipment the contact paths connected in series work directly to the voltage supply lines of the output transistors, -Triac's or -Relay. You switch safety-related directly to the consumer free of tension.

Refers to this redundant safety behavior the inventive idea of a circuit arrangement with two auxiliary contactors or equivalent Relay provides and one of these circuitry assigned error monitoring.

A preferred embodiment of the invention additional circuit with contact is in the Drawing shown. Show it

Fig. 1 Function and error monitoring circuit of the additional circuit with contact according to the invention.

Fig. 2 The emergency stop safety combination, which is supplemented by the contact-based additional control according to the invention.

Fig. 3 The locking contact arrangement of the auxiliary contactor contacts from the additional circuit with contacts in the control of the electronic input level and the voltage supply.

Fig. 4 control diagram of the dynamic error simulation in the contact-related additional circuit after switching on the control voltage or the emergency stop potential.

Fig. 1 shows the function and fault monitoring circuit of the contact-type booster circuit according to the invention. In this embodiment, the upper and lower positioning limits of linear monitors 1 and 2 are to be monitored. The positive opening safety limit switches S 10 and S 20 are intended to immediately switch off the corresponding movement sequence of the machines.

In the normal position of the machine, the safety limit switches S 10 and S 20 are not actuated and their NC contacts 21-22 are closed.

Since KO 41 and KO 51 have dropped out, the fault monitoring circuit is activated when the emergency stop potential LO 13 is connected. KO 31 switches on when NC contacts 61-62 of all other auxiliary contactors are closed. This checks whether all other auxiliary contactors have dropped out.

KO 31 holds itself over its normally open contact 13-14 , whereby the normally closed contacts 71-72 are checked by KO 51. KO 31 opens the current paths of movements 1 and 2 with break contacts 61-62 ( 71-72 ) and switches on KO 41 and KO 51 via its make contact 23-24 . KO 41 and KO 51 switch off the auxiliary contactor KO 31 due to the opening of their NC contacts 61-62 and 71-72 . Thus, the current paths for KO 11, KO 12, KO 22 close via NC contacts 61-62 ( 71-72 ) from KO 31 and NO contacts 13-14 ( 23-24 ) of auxiliary contactors KO 41 and KO 51. Up to this At the time, KO 41 and KO 51 held their own through the break contacts 71-72 of the auxiliary contactors KO 11, KO 12, KO 21 and KO 22 and their make contacts 33-34 . The NC contacts 71-72 in this current path all open because KO 11- KO 22 are switched on in the function circuit and keep themselves open via their NO contacts 13-14 . KO 41 and KO 51 switch off.

The switching process described here with subsequent behavior runs every time the supply voltage is switched on or the emergency stop potential from time to time provides a dynamic error simulation for self-monitoring the additional circuit with contacts. In this switching cycle, every auxiliary contactor opens tested its opening and closing functions. A faulty auxiliary contactor prevents the Machine function.

FIG. 4 shows a control diagram which illustrates the dynamic error simulation of the additional control with contact after the control voltage or the emergency stop potential has been switched on.

Here the time t ₁ means the response delay of the auxiliary contactor KO 31. The time t ₂ means the response delay of KO 41 and KO 51. The time t ₃ is made up of the response delay of the auxiliary contactors KO 11- KO 22 and the dropout delay of KO 41 and KO 51 together.

As shown in Fig. 1, the make contacts X of KO 11 and Y of KO 12 are connected in series. KO 11 and KO 12 release movement 1 via make contact X and give signals to the PLC (programmable logic controller) as feedback for movement 1. The same applies to KO 21 and KO 22 for make contact Y and movement 2. An error an auxiliary contactor would interrupt these contact paths as well as moving to or operating the safety switch S 10 ( S 20).

Of great advantage in the additional circuit according to the invention is that all possible mistakes can be recognized immediately in the interlock circuit, interrupt the movement of the machine and thus, there is no danger to humans or machines becomes.

In FIG. 2, supplemented by the additional circuit according to the invention is shown emergency safety combination. This switching combination also has the required redundant switching behavior.

Fig. 3 shows the arrangement of the auxiliary locking contact contactors or equivalent relay contacts from the contact-type additional circuit in the control of the electronic input plane and in the power supply. The output transistors -triac's or -relays 0.0 to 1.2 are connected to +24 V LO 11 via a circuit breaker F 4 and via the release of the emergency stop safety combination Fig. 2 via KO 3 and KO 4 33-34 with emergency stop potential LO 13 provided.

The safety contacts 23-24 from KO 11- KO 22 are connected to the voltage supply line of the Q-modules O-1 in the safety-relevant control area and, in the event of a fault in the additional circuit Fig. 1, directly disconnect the consumer V 1- V 3 in terms of current.

All Q modules 2- n , the outputs of which do not control any functions to be monitored, can be supplied directly with +24 LO 11 via an F 3 circuit breaker.

The inputs are controlled by means of actuators with +24 V LO 11 via a circuit breaker F 5 with LO 14. The make contacts 23-24 of the auxiliary contactors KO 3 and KO 4 mean the release of the control voltage via the emergency stop safety combination Fig. 2 and act on the electronics input I 0.0. The feedback from the additional circuit with the contacts 33-44 of the auxiliary contactors KO 11- KO 22 affect the inputs I 2.2 and I 2.3 of the electronics. This could, for. B. in programmable logic controllers program interventions to z. B. to activate visual or acoustic warning messages or to carry out software locking.

The invention described with reference to the drawing additional circuit with contacts for safety circuits is universally applicable. In the drawing and description is for better Manageability a simple circuit example picked up. Of course, other circuit configurations are with those characterized in the claims Features, for safety circuits possible.

Claims (3)

1. Contact-related additional control for safety circuits, in particular for monitoring the safety-relevant functional areas of electrical and electronic equipment, characterized in that the contact-related additional control ( Fig. 1) consists of a function circuit ( A ) and an error monitoring circuit ( B ), the function circuit ( A ) for Every machine movement to be monitored is assigned two auxiliary contactors or equivalent relays ( KO 11, KO 12 or KO 21, KO 22), the normally open contacts ( X or Y ) of which are connected in series, have redundant safety behavior and are directly connected to the load circuit or circuits act with safety-relevant function and indirectly through feedback on the inputs of electrical or electronic equipment, and that the fault monitoring circuit ( B ) monitors the NC contact function of each contactor or equivalent relay of the contact-based additional control ( Fig. 1) by each connection of the control voltage or the emergency stop potential ( LO 13), the function of the contact-based additional control is checked by a dynamic error simulation ( FIG. 4). 2. Contact-based additional control according to claim 1, characterized in that the contact-based additional control ( Fig. 1), the emergency stop safety circuit ( Fig. 2) or other safety circuits, supplements. 3. Contact additional control according to claims 1 and 2, characterized in that in the event of a fault, in the contact additional control ( Fig. 1) auxiliary contactor or equivalent relay, only the faulty functional circuit is switched off.