With the improvement of the domestic plastic machinery manufacturing level, the export of injection molding machines has increased, and the safety protection requirements for injection molding machines have become more and more important. CE standards or SPI standards are important standards for exporting machines, and how to effectively use them in safety standards. Configuration, which optimizes cost and equipment, is a direction of safety project design.
This article explores only a part of the safety standards for injection molding machines. It distinguishes several different points of conventional machines. These projects are subject to change with the development of plastic machinery in the future.
For the situation existing in the production of safety standard project of injection molding machine and the misunderstanding in the production process of some manufacturers, the following discusses some safety standard items of injection molding machine:
Mechanical protection device and safety device
There are three standards for safety distance in mechanical safety: preventing the upper limb from reaching the safe distance of the danger zone, preventing the lower limb from reaching the safe distance of the danger zone, and avoiding the minimum distance of compression of various parts of the human body.
The mechanical protective cover is mainly to prevent the danger of moving parts. There are mainly fixed protective devices, interlocking active protective devices, etc. The main differences between the safety items and the conventional items of the injection molding machine are:
Moving the upper cover plate in the clamping area: According to the requirements of the safety standard to prevent the upper limb from reaching the safe distance of the dangerous area, the height of the protective structure is required to be not lower than the required height in the standard. Otherwise, the upper sealing plate protection structure should be provided to prevent the upper limb Cross the protective structure to reach the danger zone.
Safety door closing distance: According to the safety standard, the minimum distance required to avoid various parts of the human body is set. The safety distance between the front edge and the operation box after the safety door is closed is generally in the form of anti-collision strip, round hollow rubber strip, plus At the front edge of the safety door and the operation box, when the safety door contacts the operation box, the computer panel is effectively protected against impact vibration and the upper limb is prevented from reaching the danger zone.
Linkage hydraulic safety lock: According to the requirements of the safety standard regarding the type of dangerous protection in the clamping area, once the front and rear safety doors are opened, the hydraulic control valve and the travel switch can simultaneously act to cut off the hydraulic power source of the mold clamping action or The power supply meets the safety protection clauses in the safety standard and can be combined with a single trip switch to increase the level of safety protection.
Others: Safety items such as the nozzle guard, the closed fuse barrel cover, and the loading port are all important.
Electrical and hydraulic protective components and wiring specifications
Valve plug wire: At present, most manufacturers adopt DIN plug connection type, which is consistent with ISO standard and conforms to CE standard. Common methods of wiring the hydraulic control valve are direct wiring method and casing wiring method. The direct wiring method is unsheathed, and the sheath wire is directly connected to the valve plug. The wiring is convenient and the cost is low, but it is not waterproof and dustproof. The wiring is not easy to be fixed, looseness may occur, and the protection requirement is not reached at the connection. , areas where protection is not available. The casing wiring method uses a (corrugated) plastic hose joint. Each valve plug has a separate hose connected to the transition junction box, which can overcome the shortcomings of the direct wiring. The protection level after using the sleeve can be It achieves the same level of protection as the hydraulic control valve.
High-pressure hose joint connection prevents the device from coming out: In order to prevent the vibration, the hose and the connecting parts above 5MPa should be able to prevent the escape or unintentional disassembly, thus causing personal injury. In the safety project, it is required to add protection at the joint of the hose joint to effectively prevent it. Damage caused by the escape or unintentional disassembly of the high pressure hose connection. Generally, the current hoses have special devices such as explosion-proof chains.