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DE-202024107387-U1 - Monitoring device

DE202024107387U1DE 202024107387 U1DE202024107387 U1DE 202024107387U1DE-202024107387-U1

Abstract

Monitoring device (100) with a light curtain (1) for monitoring access to a danger area, wherein the light curtain (1) has two sensor units arranged at opposite edges of the access, and with movable door elements (18) which project into edge areas of the access in their intended positions, wherein a safety function is triggered when at least one door element (18) is deflected from the intended position, characterized in that each sensor unit is arranged in a device column (16) wherein each door element (18) is fixedly connected to a device column (16) and wherein the device column (16) is rotatable about its longitudinal axis.

Assignees

  • LEUZE ELECTRONIC GMBH CO KG

Dates

Publication Date
20260513
Application Date
20241218
Priority Date
20241218

Claims (20)

  1. Monitoring device (100) with a light curtain (1) for monitoring access to a danger area, wherein the light curtain (1) has two sensor units arranged at opposite edges of the access, and with movable door elements (18) which project into edge areas of the access in their intended positions, wherein a safety function is triggered when at least one door element (18) is deflected from the intended position, characterized in that each sensor unit is arranged in a device column (16) wherein each door element (18) is fixedly connected to a device column (16) and wherein the device column (16) is rotatable about its longitudinal axis.
  2. Monitoring device (100) according to Claim 1 , characterized in that a conveying unit (14) runs through the access point, on which permissible objects (15) are transported, and that the widths of the door elements (18) are dimensioned such that no person can pass through the gaps between the door elements (18) and the permissible object (15).
  3. Monitoring device (100) according to Claim 2 , characterized in that the sizes of the gaps between the door elements (18) and a permissible object (15) do not exceed a predetermined maximum value.
  4. Monitoring device (100) according to one of the Claims 1 until 3 , characterized in that the light curtain (1) has as a first sensor unit a transmitter unit (2) with a series arrangement of light beams (3) emitting transmitters (4) and as a second sensor unit a receiver unit (5) with a series arrangement of light beams (3) receiving receivers (6).
  5. Monitoring device (100) according to one of the Claims 1 until 3 , characterized in that the light curtain (1) has as a first sensor unit a transmitter-receiver unit (10) with a multiple arrangement of light beams (3) emitting transmitters (4) and light beams (3) receiving receivers (6) as well as a second sensor unit in the form of a reflector unit (12).
  6. Monitoring device (100) according to one of the Claims 1 until 5 , characterized in that the light curtain (1) is a safety sensor.
  7. Monitoring device (100) according to one of the Claims 1 until 6 , characterized in that the light curtain (1) monitors a protective field, wherein in normal operation the light curtain (1) generates a switching signal when registering an object intrusion in the protective field with which a safety function is generated.
  8. Monitoring device (100) according to Claim 7 , characterized in that in a muting operation of the light curtain (1) the protective field is completely or partially bridged, wherein an object intervention in the bridged part of the protective field does not lead to the triggering of the safety function.
  9. Monitoring device (100) according to one of the Claims 2 and 8 , characterized in that the muting operation is activated while a permissible object (15) passes through the protective field.
  10. Monitoring device (100) according to Claim 9 , characterized in that the permissible object (15) passes through the protective field in its bridged area, such that the permissible object (15) passes through the protective field without the light curtain (1) triggering the safety function.
  11. Monitoring device (100) according to one of the Claims 9 or 10 , characterized in that muting sensors (17) are provided by means of which permissible objects (15) can be identified, wherein the muting operation is activated or deactivated depending on muting signals of the muting sensor (17).
  12. Monitoring device (100) according to one of the Claims 9 or 10 , characterized in that muting signals, by means of which the muting operation is activated or deactivated, are specified by a controller.
  13. Monitoring device (100) according to Claim 12 , characterized in that the muting operation can be activated by means of a gating function.
  14. Monitoring device (100) according to one of the Claims 1 until 13 , characterized in that each device column (16) is rotatably mounted on a base body (20) about its longitudinal axis.
  15. Monitoring device (100) according to one of the Claims 1 until 14 , characterized in that each device column (16) is fixed in a zero position by a snap connection, wherein in the zero position of the device column (16) the door element (18) attached to it is in its intended position.
  16. Monitoring device (100) according to one of the Claims 14 and 15 , characterized in that the locking connection is formed by at least one ball pin (30) mounted on the base body (20) and a locking receptacle (31) on a support plate (28) of the device column (16).
  17. Monitoring device (100) according to one of the Claims 15 or 16 , characterized in that , upon impact against a door element (18), the locking connection of the associated device column (16) is released and the door element (18) with the device column (16) is rotated out of the intended position.
  18. Monitoring device (100) according to one of the Claims 14 until 17 , characterized in that each base body (20) has adjustment means by means of which the rotational position and inclination of the respective device column (16) can be adjusted.
  19. Monitoring device (100) according to one of the Claims 1 until 18 , characterized in that each door element (18) is mounted in a groove extending in the longitudinal direction of the device column (16).
  20. Monitoring device (100) according to one of the Claims 1 until 19 , characterized in that each door element (18) is formed from a transparent panel or a fence element.

Description

The invention relates to a monitoring device. Such monitoring devices have a safety sensor in the form of a light curtain and a safety controller that controls the system. In this case, the term "safe" means that the respective units have a fail-safe design and meet the relevant normative requirements. The light curtain secures a hazardous area at the facility. In particular, the light curtain monitors access to the hazardous area. The light curtain features a series of transmitter-receiver pairs forming beam axes, by means of which a planar, plane-bound protective field is monitored. Typically, the light curtain comprises a transmitter unit, which integrates a series of light-emitting transmitters, and a receiver unit with a series of light-receiving receivers and an evaluation unit. With the protective field clear, the light beams of each transmitter converge on an assigned receiver, thus forming a transmitter-receiver pair and a beam axis of the light curtain. If an object enters the protective field, the object interrupts the light beams of at least one beam axis. Depending on whether an object is present in the protective field, the light curtain generates a switching signal, which the safety controller then uses to control the system. If no object is present in the protective field, the switching signal is in a state that enables the system to operate. If the light curtain detects an object in the protective field, it generates a shutdown signal, i.e., a switching signal with a state that triggers a safety function, shutting down the system. This eliminates any further hazards emanating from the system, ensuring that there is no longer any danger, particularly for a person who enters the danger zone through the protective field of the light curtain. Typically, during operation of the system, it is necessary to feed permissible objects, i.e., non-safety-critical objects such as pallets, boxes, or the like, into the system. For this to happen, these non-safety-critical objects must pass through the protective field of the light curtain. Triggering the safety function would be unnecessary in this case and would unnecessarily restrict the availability of the system by generating a shutdown signal in the light curtain and causing unnecessary downtime. To avoid such unnecessary shutdowns of the system, it is known to operate the light curtain in a muting mode. For this purpose, unauthorized objects are detected and identified using suitable muting sensors before they enter the protective field. Depending on the signals from the muting sensors, the light curtain is muted for a predetermined time interval during which an authorized object passes through the protective field. This means that the safety function of the light curtain is overridden; that is, the light curtain does not generate a shutdown signal when the non-safety-critical object passes through the protective field. In the simplest case, muting involves muting the entire light curtain, so that regardless of which and how many beam axes of the light curtain are interrupted by the permissible objects, the safety function of the light curtain is bypassed. It is also generally known to perform partial muting. In this case, only a portion of the light curtain's beam axes are muted, so that an object entering the area of these beam axes does not trigger the safety function. The remaining beam axes of the light curtain are not muted, meaning that an object entering the area of these beam axes will trigger the safety function. This partial muting is useful when the sizes of permissible objects are known, so that only the portion of the beam axes interrupted by these known permissible objects is muted. The monitoring function of the light curtain remains intact for the remaining beam axes, thus increasing the safety of the monitoring device. For example, manipulations can be detected if a person sitting on a permitted object, such as a box, attempts to pass through the light curtain's protected area. While the light curtain is partially muted when the permitted object passes, it is not muted in the area where the person is located, so the person is identified by the light curtain as a prohibited object. This is detected, which triggers the safety function. In the event that a conveyor unit carrying permissible objects runs through the access to the danger zone of a plant, a further safety risk arises when the light curtain is muted. In this case, the spaces between the permitted objects and the perimeter boundaries of the access, which are typically formed by fences, are unsecured. If the light curtain is muted, a person can pass laterally past the permitted object through the gap between the fence and the permitted object without the light curtain triggering the safety function. To prevent such hazardous situations, it is known to secure these gaps with swing doors positioned at the perimeter. The swing doors extend directly to the permitted object, so t