The injection molding machine is a kind of thermoplastic molding equipment which plasticizes the solid plastic, and then injects it into the closed mold cavity with certain pressure and speed with the help of the screw, and after curing and finalizing, obtains the products.
Injection molding machine is generally composed of injection device, mold closing device, frame, gearbox, hydraulic and electrical system and other major components.
In the process of injection molding, there are not only the rotary, linear and spiral motion of mechanical equipment, but also the kinetic energy transmission of hydraulic equipment, as well as the heat energy conversion of electric heating device, which puts forward more requirements for lubrication.
Of course, for the lubrication of injection molding machine, we can follow the general rules of mechanical equipment, hydraulic equipment and electric heating equipment respectively according to the motion mode, but some parts (such as injection parts and gearbox, etc.) need to be considered comprehensively and adopt the mixed lubrication method.
Good lubrication and maintenance can greatly extend the life of injection molding machine and reduce the cost for our enterprise. This is also why some enterprises have problems with their injection molding machines after they have been used for 5 years, while others have been able to use them for more than 10 years. Now let's talk about the lubrication of injection molding machine.
1、 Lubrication of manual or semi-automatic plastic injection molding machine
1. Lubrication of gearbox
Any failure of the transmission will affect the quality and quantity of processing. The hardened spur gear and quenched and tempered shaft in the box shall be provided with a uniform and reliable lubricating oil film. Generally, the oil cup and splash lubrication method can meet the lubrication requirements.
2. Lubrication of injection parts
The function of the injection part is to heat the plastic evenly to the injection temperature through the electric heating ring, and the injection pressure is formed by the screw pressure bar. Generally, the lubrication method of the pressing rod is oil cup, oil rope, etc.
3. Lubrication of clamping part
The mold locking part is composed of belt pulley, lead screw, nut, vise, etc. Adjust the position of the ram on one side of the vise to match with the travel switch on the base to control the feed stroke of the screw rod, so as to make the vise open and close the die. Because the friction joint of screw rod and nut is small, the oil film is easy to be squeezed and cracked, so the lubricating oil should have better oil property. Generally, l-an46 oil or HL hydraulic oil is used to lubricate through oil cup and oil rope.
4. Lubrication of base part
The slide guide on the base is generally made of cast iron. Because the load and speed of the guide rail are not large, a certain boundary oil film can be ensured by using mineral lubricating oil. Generally, when you touch the guide rail surface with your hand gently, you can see the oil trace on your hand, which means that a layer of oil film has been maintained on the guide rail surface.
2、 Lubrication of automatic hydraulic injection molding machine
The features of this injection molding machine are: high automation, stable performance, electrical and hydraulic interlock protection device, high precision and complex structure.
1. Lubrication of injection part
Because this part is the key part of the injection molding, which completes the injection double cylinder pulling the pre plastic gearbox, pushes the screw through the gearbox, and injects the evenly plasticized plastic into the film cavity. The movement is frequent, and there are electric heating devices, so the lubrication system must be strictly implemented. Main lubrication parts of this part:
① Add l-an46 total loss system oil to the injection base and rack guide rail surface once a shift.
② Add l-an46 total loss system oil to the guide rail surface at the bottom of gearbox (roller), once per shift.
③ . grease the turning center, about 0.3L.
④ Add about 10L of l-an46 total loss system oil into the gearbox.
2. Lubrication of moving parts
The hydraulic power and direct pressure filling device are adopted for the mould transfer, which are simple in structure, reliable in operation and few in lubricating points. The main purpose is to ensure the formation of lubricating oil film on the four guide pillars, which can be lubricated by l-an46 mechanical oil through oil cup and oil rope.
3. Motor lubrication
Most of the automatic hydraulic injection molding machines are driven by multiple motors. During the daily lubrication, the motors should be lubricated according to the requirements.
According to iso8681-1985, China has formulated gb7631.1-87 classification of lubricants and related products (L category), which is divided into 19 groups according to the application occasions and fields of lubricants. Where l represents lubricant class, a represents total loss system, and N represents the first letter of viscosity. 46 for viscosity index. Therefore, l-an46 must be the oil for full loss system, and it can never be used as hydraulic oil, because hydraulic oil is indicated by the letter H. N-46 refers to lubricating oil with viscosity index of 46.