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Use safety relays properly to prevent mechanical safety accidents. http://yunrun.com.cn/tech/2626.html In the zinc ingot stacking operation line of Shift 307 in a smelting plant, operator A entered the area where the automatic ingot stacking machine was operating through the unsecured safety gate, without shutting down the machine first. He carried out cleaning work within the operating radius of the robotic arm. When he moved to the area where the ingots were taken from the machine, the ingot handling device received signals from the water-cooled chain conveying the zinc ingots; these signals were sent to the robotic arm, which then automatically rotated to pick up the ingot. As a result, Jin was pushed against the ingot handling device, and the gripping mechanism used to hold the ingot pressed against his left chest. Figure: As victim A entered the operating radius of the robotic arm, zinc ingot packing worker B immediately activated the emergency stop switch and called for help from people nearby to carry out rescue efforts. After Team Leader C of Shift 307 in the casting process arrived at the scene, he organized the staff to remove the foot bolts of the robotic arm and used an electric single-girder crane to lift the arm, rescuing the injured person 19 minutes after the accident occurred. Emergency responders arrived at the scene to provide first aid, and the victim was then transported to the County’s Second People’s Hospital where they died despite efforts to save them. According to relevant reports, one-third of all production accidents worldwide are mechanical safety incidents. If we open the Pandora’s box of accidents, it is not difficult to see that the causes of safety incidents in machining can be simplified to: employee exposure and equipment failure. However, in this case, although the company has clear regulations stating that \"it is strictly prohibited to enter the area where the robotic arm is operating,\" and that \"operators may enter the operational radius only after the robotic arm has been powered off,\" this also means that one of the principles required for preventing mechanical risks – the principle of isolation and shutdown – can only be enforced through administrative measures. The actual safety facilities on site are inadequate; the safety gates and barriers are not properly interlocked with the robotic arm, leaving operators exposed to danger... Thus, we cannot help but consider the following hypothesis: Hypothesis 1: Install a safety door lock switch on the safety gate. The safety door switch consists of two separate components: the switch body and its actuating element. When the safety guard door is opened, the switch actuator is pulled out of the switch body, and at this point the normally closed contacts inside the switch are disconnected by a mechanical rebound mechanism. As soon as the operating element is pulled out of the main body, the controller immediately cuts off the power supply to stop the movement of the components inside the guard rail. In the aforementioned accidents, if a safety door lock switch were installed on the safety door of the guardrail, then as soon as Kim opened that safety door, the robotic arm would lose power and stop operating. Combined with the procedure of locking and labeling, this ensures that once Kim enters the protective enclosure, the robotic arm remains powered off, which not only complies with the company’s regulations but also safeguards his own safety. Hypothesis 2: Installing safety mats within the operating radius of the robotic arm. Safety mats are a type of pressure-sensitive safety device; when a predetermined minimum weight is applied to the mat, the switch is turned off, and the controller then sends a stop signal to the machine being protected in order to halt its movement. It provides reliable protection for operators from various potential hazards. In the aforementioned accidents, if a safety carpet is laid within the operating radius of the robotic arm (with a certain safety distance maintained), then once Kim steps into the dangerous area, the controller can put the robotic arm into a power-off state to protect the safety of the people. Life comes with no assumptions, and safety in work must not be taken lightly. As workers become familiar with repetitive tasks over time and their understanding of potential risks becomes incomplete, they tend to let their guard down. The likelihood of accidents resulting from negligence or improper procedures **increases**! At this point, the necessity of installing safety interlocks becomes self-evident. As mentioned above, detection devices such as door locks, safety mats, or safety edges have their signals routed through safety relays and interlocked with the operation signals of the machinery, ensuring that any intrusion is detected promptly and that the machinery does not start up. Among them, the function of the safety relay is to ensure that the detection signal can be transmitted accurately. Architecture diagram of machine equipment control system using safety relays: http://yunrun.com.cn/upload/201907/18/201907180230014625.png