Maintenance and Care of Die Casting Machine 3

6 Lubrication part

6.1 Grease / monthly inspection

All grease nipples of the whole machine should be greased once a month, and lithium-based grease and molybdenum disulfide grease should be used. Note that the grease at the sliding bearing of the movable seat plate should not be injected too much so that the dust seal can slide out of the hole.

6.2 Machine hinge lubrication / daily inspection

Before operating the machine every day, the lubricating pump should supply oil to the lubricating system, and it is not allowed to start the machine after the lubricating alarm forcibly.

6.3 Lubricating oil pipe/weekly inspection

Check the lubrication pipelines of the toggle lubrication system and the hammer lubrication system every week. It is required that each lubrication pipeline has sufficient lubricating oil to ensure that the lubricating oil pipeline is unobstructed. If the lubricating oil pipe joint is loose or falling off, it should be dealt with in time.

6.4 Mold adjusting device/monthly inspection

If the mold adjusting device is lubricated with grease, it should be filled once a month. Before filling, clean the surface of the die adjusting nut and the screw motion pair, the contact surface between the gland and the nut, and the sprocket or gear transmission, and then evenly apply grease.

6.5 Ejection cylinder guide rod/check every three months

The guide rod of the ejector cylinder is lubricated with grease once every 3 months.

6.6 Slide seat and steel plate (belt)/monthly inspection

If the sliding seat and steel plate (belt) are lubricated with grease, they should be lubricated once a month. Before filling, remove the sliding feet of the middle plate, wash them with clean diesel oil, wipe off the dust and sundries on the surface of the steel plate (belt), then install the sliding feet of the middle plate, and use an oil gun to inject into the oil groove of the sliding feet. An appropriate amount of grease is ideal; apply a thin film of oil on the steel plate.

6.7 Reasonable selection of lubricating oil

Do not mix several grades of oil to ensure that the lubricating oil is not polluted, and do not use deteriorated lubricating oil. The high-quality lubricating oil can make the die-casting machine run smoothly; prevent scratches on the friction surface; prevent the parts of the machine from rusting and not corroded; reduce the loss of lubricant. It is recommended to use No. 68 Caltex high-quality machine tool slide lubricant (Way Lubricant) as the toggle lubricant for die casting machines.

6.8 Hammer lubrication (cold room)

The injection hammerhead of the cold chamber die casting machine should be lubricated with high-quality lubricating oil or lubricant.

7 Cooling system

7.1 Cooling system connection / annual inspection

Every year, each connecting water pipe of the cooling system should be overhauled to observe whether the water pipe is corroded or leaked; otherwise, it should be repaired or replaced in time.

7.2 Cooling water tower

The cooling water of the machine should be purified as fresh water, the water tower must filter the river water, and the filter device of the water tower should be cleaned every six months.

7.3 Cooler/semi-annual inspection

After the cooler usually works for half a year, the surface of the tube wall is fouled, and the heat exchange performance is reduced.

7.4 Check the cooling system effect

The cooling system should ensure that the hydraulic oil temperature does not exceed 55℃ when the machine is working continuously, and the surface temperature of each oil cylinder does not exceed 60℃.

7.5 Prevent condensation

When shutting down for a long time in freezing weather, release the fresh water in the cooler to avoid condensation.

8 High-temperature parts

8.1. Injection chamber and plunger tip

8.1.1 Material temperature

The temperature of the aluminum alloy feed liquid is controlled to be 620-680 °C, and the temperature of the zinc alloy feed liquid is controlled to be 400 to 430 °C. If the material temperature is too high, it will speed up the wear and corrosion of the hammerhead, steel order, injection chamber (feeding barrel), material pot, and even stick the hammer.

8.1.2 Cleaning up the slag

Clean up the scum on the alloy liquid surface in the crucible in time. Once the alloy slag enters the injection chamber (or the barrel of the material pot), it will strain the injection chamber (the barrel) and the surface of the hammerhead.

8.1.3 Plunger Tip lubrication

The cold chamber die-casting machine should be regularly added with plunger tip lubricant to ensure the lubrication effect of the plunger tip. Do not use hydraulic oil and engine oil to replace the plunger tip lubricant.

8.1.4 Preheating

Before injection, the injection chamber and plunger tip should be preheated. For a small die-casting machine, the simple method is to pour an appropriate amount of alloy solution into the pressure chamber in the state of fitting (mold), and after solidification, start the machine and push it out before the hammer repeats 2 to 3 times.

8.2 Crucible

8.2.1 Clean up

Crucibles should be cleaned before use to remove surface oil, rust, slag, and oxides.

8.2.2 Anti-corrosion coating

Metal crucibles must be preheated and coated with high-quality paint before use. It is recommended to use (NIKKIN FLUX INC) NC-8 protective coating distributed by NIKKIN FLUX INC. Its application method is as follows:

  • Preheat the new crucible to about 200℃.
  • Apply a layer of paint on the working surface after cooling.
  • Heat the crucible to make the paint dry.
  • In order to increase the protection, you can apply the above steps 1-2 times.
  • If it is not a new crucible, be sure to clean up the residual material in the crucible and then apply the paint. After drying, you can repaint 1 to 2 times to strengthen the protection.
8.2.3 Additives

When the new furnace is loaded with alloy materials, the alloy ingots should be stacked according to the requirements of the furnace specification, and the alloy ingots added later are required to be immersed in the solution. All alloy ingots must be clean and dry.

8.2.4 Stop scooping

For aluminum alloy furnaces, if the downtime is too long (generally more than 8 hours), all the alloy melt should be scooped out. And at least two-thirds of the zinc alloy crucible should be scooped out to reduce the corrosion of the alloy melt to the crucible, which can also be shortened. The next time the furnace is opened to melt the material, the stress of thermal expansion and contraction of the alloy liquid is reduced, and the crucible is prevented from bursting.

8.2.5 Install the burner

When installing the burner, do not direct the flame to the crucible. It should be installed at a downward angle of 3° to avoid thermal cracking caused by direct local heating of the flame.

8.2.6 Clean the bottom of the crucible / monthly inspection

Clean the refractory material at the bottom of the crucible once a month to prevent the crucible from bursting due to poor heat transfer. After cleaning the crucible, re-coat a layer of protective paint on its surface.

8.2.7 Rotate 120°/Monthly Check

For aluminum alloy furnaces, the crucible is rotated by 120° every month to prevent the crucible from cracking on one side of the crucible for a long time.

8.2.8 Inspection of furnace probes/monthly inspection

Check the furnace heat probe monthly to prevent abnormal temperature control, and clean the alloy material on the heat probe sheath at the same time.