The three major units of an injection molding machine are Mechanical devices, Hydraulic devices, Electronic and electrical devices.
These components work in conjunction with each other to form the three main categories: bases, hoppers, barrels and clamping units. In addition, there are smaller components such as nozzles, ejector pins, mould divider, clamping unit, injection unit and hydraulic unit.
The base holds all the other parts and electronics required for machine operation. The electronics on the device must control a range of heaters, hydraulics, sensors and injection pressures.
The three major units of an injection molding machine are：
- Mechanical devices
- Hydraulic devices
- Electronic and electrical devices
Below you will find our detailed descriptions of each unit.
Major unit injection molding machine-Mechanical devices
Mechanical devices are mainly composing of locking parts, injection parts, and other auxiliary parts.
Injection molding machines are mainly composing of mechanical devices, hydraulic devices, electronic devices,
Injection system: This is the core component of the injection molding machine, usually acting of a screw (or plunger), a barrel, and a feeding seat.
Driven by the transmission system, the screw conveys and compacts the plastic from the hopper, and melts the material under the action of the heater outside the barrel, and then injects the molten plastic into the mold through the screw.
The clamping device has three main functions:
First, to achieve reliable opening and closing of the mold;
Second, to ensure sufficient locking force during injection and pressure holding to prevent overflow of the plastic part;
Third, to achieve demolding of the plastic part.
The clamping device is a device that ensures that the mold is completely closed and that the mold is opened and closed smoothly according to the process requirements.
During the injection process of the injection molding machine.
The mold can still reliably remain in a closed state under the action of the clamping mechanism when the high-pressure molten material enters the cavity.
The clamping device is mainly composed of a clamping mechanism, a demolding mechanism, a mold adjustment mechanism, a template, a tie rod, etc.
Hydraulic devices
Hydraulic devices are mainly composed of hydraulic oil pumps, hydraulic oil valves, hydraulic cylinders, hydraulic pipelines, and other parts.
Used to provide motion and force control. During the injection molding process.
Hydraulic systems able to close and lock the mold and provide the necessary force to push the screw during the injection phase.
The working principle of the hydraulic system of the injection molding machine
- Hydraulic pump start
- Hydraulic cylinder action
- High-pressure injection
- Mold closing and mold opening
Hydraulic pump start:
When hydraulic pump is starting, the hydraulic oil is sucked from the oil tank and transported to each actuator in the system through the oil pipe.
Hydraulic cylinder action:
After the hydraulic oil enters the hydraulic cylinder.
It pushes the piston rod and its bearing placed in the thrust seat, thereby pushing the screw forward or backward.
The axial position of the two parallel piston rods and the axial position of the injection screw can be adjusted through the nut on the piston rod head.
High-pressure injection:
Under the piston thrust of the injection cylinder, the screw injects the molten material in the storage chamber into the mold cavity through the nozzle at high speed and high pressure.
After the molten material in the cavity is maintained under pressure, cooled, solidified, and shaped, the mold cavity is opened and the product is ejected.
Mold closing and mold opening:
The mold closing device consists of a fixed mold plate, a movable mold plate, a mold opening and mold closing mechanism, and a product ejection mechanism.
The mold closing and mold opening are achieved by controlling the speed and pressure.
Electronic and electrical devices
These are mainly composing of electronic and electrical parts to form control systems, as well as input and output power drive circuits
The electrical control system able to control the various actions and parameters of the injection molding machine.
Such as injection speed, pressure, temperature, etc., to ensure the accuracy and stability of the injection molding process.
Major unit injection molding machine-Electronic and electrical devices Working principle
- Temperature control:
- Pressure control
- Speed control
- Time control
- Sequence control
The working principle of the electrical control system of the injection molding machine showing as the following steps:
Temperature control:
During the injection molding process, the control of the barrel temperature is crucial.
The controller monitors the barrel temperature in real-time through the temperature sensor and adjusts the power of the heater according to the set value to keep the barrel temperature within the appropriate range.
Injection Pressure control:
The controller receives the signal from the pressure sensor and adjusts the output of the hydraulic system or servo motor according to the set pressure value to achieve precise control of the injection pressure
Speed control:
The controller controls the injection speed by adjusting the speed of the motor according to the speed reference signal.
Speed control usually adopts a closed-loop control method to ensure the stability and repeatability of the speed
Time control:
The controller controls the execution order and duration of each step according to the set time parameters to ensure that the injection molding process is carring out according to the predetermined procedure
Sequence control:
The controller performs the actions of mold closing, injection, pressure holding, cooling。
And mold opening in sequence according to the requirements of the injection molding process.
After each step is finish, the system will enter the next step
Haichen injection molding machine
Haichen Machine is a global manufacturer of high-precision plastic injection molding machines.
Our headquarters is centrally located in Ningbo and is an injection molding machine production factory that integrates production, sales, and after-sales service.
Haichen machine is fully equipping to support sales, service, mold trials, customer training, maintenance.
Our service teams are staffed with experienced, professional service technicians who are fully committed to supporting the success and profitability of our customers.
Haichen injection molding machine, ranging from 30 tons to 3000 tons, with more than 20 years of experience.
Haichen machine generally stocks over 100 injection molding machines for quick delivery.
