In Europe, mechanical products are required to be put on the market or delivered without jeopardizing personal safety and health, animal and plant and property safety, and the possible dangers of products are classified.

First, the general mechanical danger mainly comes from the following four parts:

In the normal use of processing machinery, if the processed parts are easy to rebound and hurt the staff, the design and manufacture of the processing machinery should be able to prevent the processed parts from rebounding, so as not to cause harm.

If the contact with the tool is still dangerous after the processing machine stops running, the processing machine must be equipped with an automatic stop device to ensure that the tool is stopped in a very short time.

If the processing machine with a tool is not a fully automated equipment, its design and manufacturing should prevent injuries, or use a tool with a circular cross section and limit its cutting thickness to keep the hazard to a minimum.

Mechanical hazards: mainly from moving components, including crushing, shearing or kinking caused by moving shafts and transmission mechanisms. Experts recommend the use of fixed or mobile shields to prevent personnel from approaching the hazardous area.

Second, the safety of machinery should consider the following:

1. Component requirements

Control circuits related to safety functions must use mature components in the design, selection and assembly process, that is, they have been widely and successfully used in similar applications, or components manufactured according to reliable safety standards, and Use proven technology. The safety control circuit must be able to withstand the expected operating intensity, and be able to withstand the effects of the working medium and the related external environment during operation. When designing a circuit, extremely safe and reliable components should be used, and the possibility of failure of such components itself can be ignored. At the same time, in order to avoid short circuits, reduce the incidence of faults, determine the types of faults, accurately detect faults and avoid the occurrence of secondary faults, such as isolation circuits, sufficient load carrying capacity, timely open-circuit power failure when a fault occurs, Grounding and other measures.

2. Machine Safe Stop Requirements

The core of the safety protection of machinery and equipment is to stop the dangerous actions of machinery and equipment. How to stop the machinery and equipment from running to stop is very important. Depending on the safety protection device used, there can be different safety stop functions. The stop function used in normal operation must be able to prevent the equipment, products and processing processes from being damaged, and at the same time prevent the restart of the machine and equipment. This is the requirement for the safe stop function.

In paragraph 9.2.2 of the EN60204-1 standard, three stop categories are specified:

Stop category 0: Stop is realized by immediately cutting off the power supply to the equipment, that is, the stop is not controlled.

Stop category 1: controlled stop, the power supply to the actuators of the machinery and equipment is always maintained to gradually stop the machinery and equipment. The power is cut off only when the machine equipment is completely stopped.

Stop category 2: Controlled stop, the power supply to the drive equipment of the equipment is maintained.

The selection of the correct stop category must be based on a risk analysis of the machinery and equipment, which is specified in the prEN954-1: 1994 standard.

All equipment must have a stop function of stop category 0. The stop functions of stop categories 1 and 2 can only be used if the safety and functional requirements of the machine are necessary.

3． Use of two-hand control

In many highly dangerous machines, such as forging equipment, punching and shearing equipment, both-hand control devices are used. The two-hand control device is an electro-sensitive safety protection device. Its role is to force the machine to use both hands when someone is operating the machine and give a signal that the machine is producing a dangerous action, so it must stay in a place to ensure safety. .

4． Safe distance solution

(1) It can be realized by safety door switch lock, electro-sensitive safety protection device, safety carpet and two-hand controller.

(2) In the safety protection of machinery and equipment, in addition to using safe and reliable protection elements, for very dangerous machinery and equipment, certain requirements must be made on their safety protection control circuits to improve the level of safety protection, such as Security monitor module.

5． Use of safety carpet

In the safety protection of machinery and equipment, in some occasions, it is impossible to use a safety fence and a safety protection door to protect the dangerous area. For example, in some large injection molding machines, it is often necessary to maintain and adjust the inside of the machine. At this time, it is necessary to ensure that It is not possible to start the machine from outside, in which case it is obviously not possible to use a safety door. In addition, in some occasions where a safety protection door can be used, for convenience and aesthetic considerations, it may not be willing to use a safety protection door. In the above two situations, in order to realize the safety protection of the dangerous area, a contact type safety protection device can be used. In this type of safety protection device, safety carpet is a very distinctive and widely used type.