CE certification directives for machinery recommendations and requirements

About mechanical CE certification,Global Technical service Co. Ltd. Certification Testing Institute provides you with recommendations and requirements for machinery for CE certification directives.
　　The general mechanical hazard comes mainly from the following four parts：
 
　　1、When the processing machine is used normally, if the workpiece is easy to rebound and hurt the staff, the design and manufacture of the processing machine should prevent the rebound of the workpiece to avoid harm；
 
　　2、If the contact with the tool is still dangerous after the machining machine stops running, the machining machine must have an automatic stop device to ensure that the tool is stopped in a very short time；
 
　　3、If the processing machine with the tool is not fully automated, it should be designed and manufactured to prevent injury events; or use a circular section of the tool and limit its cutting thickness to keep the hazard to a minimum.
　　4、Mechanical hazard: mainly from moving components, including the danger of crushing, shearing or twisting caused by the moving shaft and the transmission mechanism. Fixed or mobile shields are recommended to prevent personnel from accessing hazardous areas，
 
　　Several suggestions that the sewing machine head should consider when being designed：
 
　　1、The breakage of the needle during use can cause injury to the artificial personnel, even to the eyes, etc., and can be protected by adding a shield or a needle guard.
 
　　2、Fingers are also required at the tip of the needle.
 
3、Add a protective cover to the belt and so on.
 
　　Some points that the injection molding machine should consider:
 
　　1、Component requirements: Control circuits related to safety functions must use well-established components in the design, selection and assembly process, ie extensive and successful use in similar applications, or components manufactured according to reliable safety standards. And use mature technology. The safety control circuit must be able to withstand the expected operational strength and withstand the effects of the working medium during operation and the associated external environment. Use of proven components, that is, extensive and successful use in similar applications, or components manufactured according to reliable safety standards, and the use of proven technology. When designing a circuit, components that work extremely safely and reliably should be used, regardless of the possibility of failure of the component itself. At the same time, in order to avoid short circuit, reduce the incidence of failure, determine the type of fault, accurately detect the fault and avoid the occurrence of secondary fault, you can use such as: isolation circuit, sufficient load capacity, timely open circuit power failure in case of failure, good grounding and other measures.
 
2、Safe stop of the machine: the safety protection of the machine and equipment, the core is to stop the dangerous action of the machine,how to move the machine from running to stopping is very important. Depending on the safety device used, there can be different safety stop functions. The stop function used in normal operation must be able to avoid damage to the machine equipment, products and processes, and to prevent the machine from being restarted. This is the requirement for the safety stop function.
 
In paragraph 9.2.2 of the EN60204-1 standard, three stop categories are specified:
 
- Stop category 0：The stop is achieved by immediately cutting off the power supply to the machine, ie the stop is not controlled.
 
- Stop Category 1: Controlled stop, the power supplied to the machine's actuator is maintained, so that the machine is gradually stopped. The power is turned off only when the machine is completely stopped.
 
- Stop Category 2: Controlled stop, the power supplied to the machine's drive unit is maintained.
 
1、The choice of the correct stop category must be based on a risk analysis of the machine and equipment, as specified in the prEN954-1:1994  standard.
 
2、All machines must have a stop function that stops category 0. Stopping the stop function of category 1 and / or 2 is only available if the safety and functional requirements of the machine are necessary.
 
3、The use of two-hand control devices: In many dangerous machines, such as forging equipment, punching equipment, etc., two-hand control devices are used. The two-hand control device is an electro-sensitive safety protection device. When a person operates the machine equipment and gives the machine equipment a signal to generate dangerous actions, it is forced to use both hands at the same time, so that it must be in one place, thus ensuring safety.
 
4、Safe distance solution: A can be used in the safety protection of machine equipment by using safety door switch lock, electro-sensitive safety protection device, safety carpet and two-hand controller.  In addition to the use of safe and reliable protection components, for very dangerous machinery and equipment, it is also necessary to make certain requirements for its safety protection control circuit to improve the level of safety protection, such as: safety monitor module.
 
5、Use of safety carpets: In the safety protection of machinery and equipment, in some cases it is impossible to use safety fences and safety guard doors to protect dangerous areas. For example, in some large-scale injection molding machines, it is often necessary to perform maintenance and adjustment inside the machine. In this case, it is necessary to ensure that the machine cannot be started externally. In this case, it is obviously impossible to use the safety protection door. In addition, in some cases where safety protection doors are required and can be used, it is also possible to use safety protection doors for convenience and aesthetics. In both cases, in order to achieve safety protection for hazardous areas, contact-type safety devices can be used. In this type of safety protection device, the safety carpet is very distinctive and is also a widely used one.