Occupational hazards and protective measures of mold work

1. Occupational hazards

The main occupational hazards of light metal forging are:

1. Accidents. The die forging workshop produces aluminum alloy forgings, and accidents of lifting injuries, scalds from hot workpieces, and band saw cuts often occur.

Free forgings and die forgings are processed on vertical hydraulic presses. In the free forging of aluminum alloy, if the blank is not clamped, set up, loosened and eccentric, the forging will run away. When forging punching parts, if the upper and lower dies are not matched, the lower dies can be forced to fly. It is even more dangerous if the clamp is not firm and the clamp is facing the abdomen.

When using die forging hydraulic press for forging, the forging temperature range is very narrow, in order to prevent rapid heat dissipation, the mold must be preheated, and the preheating temperature is 250～420℃. Contact with hot molds and hot workpieces may cause burns. When the mold is installed, it must be clamped upright. Tighten the mold and fix it with iron wedge. It is also very dangerous to use a crane to hit the iron wedge with a hammer.

When free forging and molding aluminum alloy, such as visiting the mold or workpiece under the movable beam, it can not only cause crushing, but also may slip and fall due to the oil on the ground, and accidentally touch the hot mold or hot workpiece and burn it.

Due to the different specifications of the production die forgings, the die needs to be replaced frequently. The upper and lower molds of the mold are hoisted at the same time. The weight is heavy and the hoisting is frequent. A slight error in the hoisting will hurt people. Lifting rods must be used for loading and unloading molds into the mold heating furnace, and loading and unloading molds on the hydraulic press. The selection of lifting rods must be matched with the lifting holes, such as using large diameter lifting holes, small diameter lifting rods, or other steel rods instead of lifting rods, the lifting rods will collapse during lifting.

Die forgings have certain flash, which must be cut off with a band saw. Band saws are equipment with very high cutting speeds. Saw blade breaks often occur. Careless operation will cause cuts.

2. Acid mist. In order to clean the surface of the die forgings, remove graphite powder and oil stains, and check the surface defects for repairing, the die forgings need to be pickled and alkali washed. The acid and alkali mist generated will irritate the human respiratory tract.

2. Preventive measures:

1. When producing free forgings or die forgings, the forgings should be placed in the center of the hydraulic press and should not exceed the eccentricity value. The mold should be installed on the center of the hydraulic press to prevent the workpiece from flying off the workpiece or damage to the equipment due to excessive eccentricity. The pneumatic wedge iron device is used for loading and unloading molds, which is safe and reliable, and can reduce cumbersome physical labor.

In order to make the forgings easy to take out from the die cavity, lubrication is required. The lubricant is a mixture of graphite and spindle oil. When applying lubricant to the mold cavity and molded parts, it is not only easy to catch fire, but also produces black smoke, so a long handle must be used

Oil brush. The black smoke produced should be exhausted with a ventilator. During the molding process, no one is allowed to visit the mold and the workpiece under the movable beam. If you need to visit, you can move the workbench out. Install hot molds, take hot wool, and hit hot die forgings

Printing, should wear gloves to prevent burns. The molded work piece should be packed in the material basket. The work site should be kept clean, and the oil on the ground should be cleaned up in time to avoid slipping and injuring people.

Reasonably select the slings and slings for lifting the mold, and adopt the correct method of lifting the mold. When lifting, the upper module cannot be large and the lower module is small; the small diameter lifting rod cannot be inserted into the large diameter lifting hole for lifting.

2. In addition to ventilation and exhaust measures, isolation measures are adopted for pickling and alkaline washing of aluminum alloy forgings, that is, personnel operate in a room with glass isolation to prevent the harm of acid and alkali mist. Try to avoid artificial lifting acid

The tank pours acid into the sink to reduce the hazard. It is best to add acid outdoors, make a platform, install pipelines, use valves to control the flow of acid liquid, and gradually add it to the sink to eliminate the risk of acid mist and burns.