Injection molding machine CE certification safety analysis/Injection molding machine CE certification query/What is CE certification

Ningbo Aihua Testing Technology Co., Ltd.
Telephone Wang Zhengke
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Address Ningbo High-tech Zone
Wante Business Center Building, Yangmaqi Road
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1. Overview Injection molding machinery has the ability to mold plastic products with complex shapes, precise dimensions or dense texture with metal inserts in one go. It is widely used in national defense, electromechanical, automobile, Transportation, building materials, packaging, agriculture, culture, education, health and various fields of people's daily life. The working principle of the injection molding machine is similar to that of a syringe for injection. It uses the thrust of the screw (or plunger) to inject the plasticized plastic into the closed mold cavity. The process of obtaining finished products after curing and setting. Injection molding is a cyclic process. Each cycle mainly includes quantitative feeding, melting, plasticizing, pressure, injection, mold filling, cooling, mold opening and removal. After taking out the plastic part, the mold is closed again and the next cycle is carried out. A general injection molding machine includes an injection device, a mold clamping device, a hydraulic system and an electrical control system.
2. Risk Analysis
Any piece of machinery has certain dangers. A safe machine must be able to perform its functions, installation, commissioning, maintenance and disassembly without causing any harm to workers throughout its service life. According to European standards
, the safety level requirement of injection molding machinery is level 1 or above. The dangers mainly exist in the mold clamping area, clamping mechanical device area, neutron moving area, ejector pin driving mechanism, nozzle area, injection molding unit area, discharging area, etc., including mechanical hazards, high-pressure liquid release hazards, and electrical hazards. , dangers caused by heat sources, dangers caused by gas, steam, dust, etc. We can identify and evaluate the above dangers and risks according to European standards
and injection molding machinery standards
, and then take appropriate measures to reduce their risks, isolate their dangers, and finally design and manufacture a safe injection molding machine. mechanical.
For the entire machine, an emergency stop button can be installed according to European standards. Once the emergency stop button is triggered, it must send an action that overrides all other signals and cuts off the power to the motor and valve to make the machine Safe stop.
For the mold closing area, the movement of the template can cause fatal injuries to the operator. We must add safety protection devices to isolate dangers from workers, and ensure that when the safety protection devices are triggered, the machine must stop safely. According to European standards
and
, we use a forced disconnection contact switch and a non-forced disconnection contact switch as the monitoring input signal of the safety door. When the front door is opened, stop all actions in the mold closing area, including cutting off the power supply to control valves such as mold closing and injection. When the back door is opened, not only the action in the mold clamping area needs to be stopped, but the power to the motor must also be cut off. The top cover protective door can use a forced open contact switch as the monitoring input signal. When the top cover is opened, stop all movements in the mold closing area.
At the same time, a cam valve must be installed under the safety door. When the door opens, the cam action controls a shut-off valve to disconnect the hydraulic circuit. For this cam valve, we need to monitor its working status. If this stop valve fails, the power supply to the valves controlling mold closing, injection, etc. needs to be cut off.
For the injection molding unit area, we must add injection protection doors to reduce the risk in this area. When the injection protection door is opened, cut off the power supply to the valves that control injection, seating, and discharging.
According to different applications, mode switching switches, key locks or enable buttons can also be used in injection molding machinery to control operations and actions in special modes - for example, after opening the door, some valves, Perform operations such as mold opening and ejection.
According to different specifications of injection molding machinery, the tie rod distance can be used to determine whether a safety carpet needs to be installed. For automatic safety doors with pneumatic devices, it can be evaluated according to the level to consider whether it is necessary to use an edge switch and connect the signal to the safety system to protect the operator during the closing process of the safety door.
Since the safety level of injection molding machinery is required to be above level 1, the above safety input and safety output signals must be controlled by a reliable system, such as safety relay or safety. If we control the above safety input and safety output signals by a non-safety system, such as ordinary or industrial, once any fault occurs in these systems - such as irregular processor operation, output short circuit, input welding, etc. - This will cause the safety protection device to fail. The special safety module adopts a redundant structure, coupled with a reliable circuit structure and various detection circuits, so that it can meet the requirements of high safety level.
The above safety functions can be controlled by a single safety relay, and then the outputs of these safety relays are logically connected through hard wiring, and finally the corresponding safety outputs are controlled. However, such a solution can cause many problems. First, costs increase. In order to achieve a high safety level, a safety relay must be used to control a safety function. This not only increases the implicit usage cost of the security module, but also increases the wiring cost and implicit design cost. Secondly, fault diagnosis is difficult. Since the logical relationship between various safety functions is completed using hard wiring, diagnosis and maintenance will inevitably become extremely difficult when both a certain safety level and logical functions must be achieved. Third, poor scalability. If additional safety functions are to be added to this safety system, wiring changes and the installation of safety modules will bring more workload. Therefore, a single safety relay solution is not suitable for this application.
For such an application where the safety function is between It is a multifunctional, freely configurable modular security system. Unlike other safety relays, the safety circuit can be easily generated on a PC using graphical configuration tools. It consists of a basic module and several extension modules. The basic module can be used alone, including an input point that can be connected to all safety functions such as emergency stop buttons, safety doors, and two-hand controllers, a semiconductor safety output with a capacity, a relay safety output, an auxiliary non-safety output, and a test pulse output. Expansion modules can be used to add input and output points, speed monitoring, and fieldbus connection functions. Programs can be written directly to the smart card through the interface on the basic module, or a card reader can be used to write programs to the smart card and then insert and run them.
It has the following characteristics
Modular structure, flexible use
There are already versions of basic modules,,, and. The input and output modules cannot be expanded, but the communication module can be expanded. The input and output modules and communication modules can be expanded and are basic modules specially developed for the press. For small injection molding machinery, safety function control can be used. For medium and large-sized injection molding machines, especially those with mode selection or key lock functions, a structure with input and output expansion modules can be used for control.

Programmable, easy to operate, no special programming knowledge required
Use graphic configuration tools for programming, thereby achieving more configurations and less wiring. There are multiple language versions, including Chinese, German, English, Spanish, French, Italian, and Japanese. By simply dragging with the mouse, you can quickly complete a safety circuit, shortening the design and development cycle. Each basic module requires a card to store programs. Programs can be downloaded to the base module in two ways. Programs can be downloaded to the card via a card reader. Programs can be downloaded to the base module via a serial cable and the serial port on the base module. If functionality expansion is required, updates can be made within the program without cumbersome changes to the hardwiring.

Powerful diagnostic function
Fault diagnosis can be carried out in the following ways
) Each input and output point has an indicator light
) It can be used through serial cables and basic The serial port on the module performs dynamic program display function for fault diagnosis and equipment debugging
) Faults can be quickly determined through fault stack information
) The status of each function block can be judged through diagnostic words
/> ) can be used in conjunction with to obtain visual diagnostic information through the human-machine interface