Principles, functions and precautions of safety light curtains
1. The use of safety grating
The safety grating is also the photoelectric safety protection device (also called safety protector, punch protector, infrared safety protection device, etc.). In modern factories, people and machines work together, on some potentially dangerous mechanical equipment, such as stamping machinery , Shearing equipment, metal cutting equipment, automated assembly lines, automated welding lines, mechanical transmission and handling equipment, hazardous areas (toxic, high pressure, high temperature, etc.), easily cause personal injury to the staff.
1) Safety gratings are also called photoelectric protectors, safety light curtains, photoelectric protection devices, etc. They are mainly used in machining equipment and hazardous work areas to prevent mechanical equipment from harming operators and personal injuries caused by entering dangerous areas by mistake , Protect personal safety.
2) For the press that the slider can stop at any position of the stroke, install the safety grating to realize the safety protection of the entire stroke or cooperate with the cam switch to realize the safety protection of the stroke between 30° and 180°.
3) For industrial manipulator injection molding machines, packaging equipment paper cutting machines, filter machines, automation equipment, welding assembly lines and other hazardous work areas, install safety gratings, which can alarm when entering dangerous areas or interlock with the safety protection system of the equipment, thereby Protect personal safety.
2. Composition of safety grating
The illuminator is composed of a number of light-emitting units and emits infrared light.
The light receiver, the safety light curtain is composed of several light receiving units, which receive infrared light and correspond to the light emitter to form a protective light curtain to generate light-through and light-shielding signals, which are transmitted to the controller through a signal cable.
Controller: Supply power to the light emitter and the light receiver, and process the light-on and shading signals generated by the light receiver, and generate control signals. The brake control loop of the machine tool or the alarm device of other equipment can be used to realize the parking or safety alarm of the machine tool. . The controller can be divided into built-in controller (Q) and external controller (W); the built-in controller has a small and compact structure and can be installed in the electrical cabinet of machine tools or other equipment; the external controller has a beautiful and firm structure. It can be directly installed on the wall of the machine bed or other equipment. Signal cable: used to transmit the signal between the controller and the light emitter and the light receiver.
The control cable is used to connect the controller and the control unit of the machine tool and equipment to realize the safety control of the machine tool and equipment.
Under abnormal conditions, when there are obstructions in the protection area of the light scale sensor, such as when the staff enters, the light is interrupted. The grating sensor immediately sends an interruption signal to the controller. The equipment is stopped and cannot be started, thereby protecting the staff from injury.
3. Matters needing attention
1) The existence of blind spots:
Due to the defects of the installation and the grating itself, the grating has some areas when in use, and shielding the grating in the blind area does not provide protection, so special attention should be paid when using it.
When installing new equipment, try to use non-area gratings
2) Strict inspection
Before each shift, it is necessary to check whether the control of the equipment measures by the safety grating is normal.
Do not change the position of the grating at will during use.
3) When malfunctions occur, they should be repaired by professional staff.
4) During use, be careful not to allow workpieces, tools, waste, etc. to collide with the photoelectric protection device.
5) The optical surface of the grating needs to be cleaned regularly.
It is forbidden to short-circuit the control signal along with the competition
Some workers short-circuit the control signal because the grating is damaged and cannot produce in a short time, making the control system think that the grating is normal. However, once the operator puts his hand or other body parts in the dangerous area, a personal injury accident will occur. Therefore, Do not short-circuit the safety device for others.
