What are the components of injection molding machine manipulators?

The mechanism composition of injection molding machine manipulator:

First, the implementation system mechanism

The actuator of the manipulator is divided into hand, arm and trunk;

1. Hands

The hand is mounted at the front of the arm. The inner hole of the arm is equipped with a drive shaft, which can pass the application to the wrist to turn, stretch the wrist, and open and close the finger.

The structure of the manipulator hand is modeled after the human finger, which is divided into three types: articulation-free, fixed and free. The number of fingers can be divided into two fingers, three fingers, four fingers, etc., of which the second finger is the most used. According to the shape and size of the clamping object equipped with a variety of shapes and sizes of the chuck to meet the needs of the operation. The so-called hands without fingers generally refer to vacuum or magnetic suction cups.

2. Arms

The role of the arm is to guide the fingers to accurately grasp the workpiece and deliver it to the desired position. In order for the manipulator to work correctly, all three degrees of freedom of the arm must be precisely positioned.

3. Torso

The torso is the bracket for mounting the arms, power source and various actuators.

Second, drive system mechanism

There are four main driving mechanisms used by the manipulator: hydraulic drive, pneumatic drive, electrical drive and mechanical drive. Among them, hydraulic drive and pneumatic drive are the most used.

1, hydraulic drive type

Hydraulically driven manipulator is usually composed of hydraulic motor (various cylinders, oil motors), servo valve, oil pump, oil tank and other driving system, which is carried out by the driving manipulator actuator. Usually it has a great snatch capacity (up to a few hundred kilograms or more), which is characterized by compact structure, smooth action, shock resistance, shock resistance, good explosion-proof, but the hydraulic components require high manufacturing accuracy and sealing performance, otherwise the oil leakage will pollute the environment.

2, pneumatic drive type

Its drive system is usually composed of cylinders, air valves, air tanks and air compressors, which is characterized by convenient air source, rapid action, simple structure, low cost and easy maintenance. However, it is difficult to control the speed, and the air pressure cannot be too high, so the snatch ability is low.

3, electric drive type

Electric drive is one of the most commonly used driving methods for manipulators. It is characterized by convenient power supply, fast response, large driving force (joint type holding weight has reached 400kg), convenient signal detection, transmission, processing, and can use a variety of flexible control schemes. The driving motor generally adopts stepper motor and DC servo motor (AC) as the main driving mode. Due to the high speed of the motor, it is usually necessary to use a decelerating mechanism (such as harmonic drive, RV cycloidal pin wheel drive, gear drive, spiral drive and multi-bar mechanism, etc.). The manipulator has begun to use a large torque, low speed motor without deceleration mechanism for direct drive (DD), which can simplify the mechanism and improve the control accuracy.

4, mechanical drive type

Mechanical drive is only used when the action is fixed. Generally, CAM linkage mechanism is used to realize the specified action. It is characterized by reliable action, high working speed and low cost, but it is not easy to adjust.

Others also use hybrid drive, that is, liquid-gas or electric-hydraulic hybrid drive.

3. Control system

The elements of manipulator control include work order, arrival position, action time, movement speed, acceleration and deceleration speed, etc.

The control of manipulator is divided into two kinds: point control and continuous trajectory control.

The control system can be designed using digital sequential control according to the requirements of the action. It must first prepare a program to be stored, and then according to the specified procedure, control the manipulator to work.

There are two ways of storing the program: separate storage and centralized storage. Separate storage is to store the information of various control factors in more than two kinds of storage devices, such as the sequence information stored in the latch plate, CAM drum, punch belt; Position information is stored in time relay, constant speed rotary drum, etc. Centralized storage is to store all the information of various control factors in a storage device, such as tape, magnetic drum, etc. This method is used in situations where sequence, position, time, speed, etc. must be controlled at the same time, that is, in the case of continuous control.

The latch plate is used in situations where a rapid change of program is required. Change a program only need to change a latch board limit, and the same plug-in can be used repeatedly; The program length of the perforated tape is not limited, but if an error occurs, it must be replaced entirely; The information capacity of the punch card is limited, but it is easy to replace, save and reuse; Magnetic cores and drums are only suitable for applications with large storage capacity. As for which control element to choose, it is determined according to the complex and precise procedures of the action.

For the manipulators with complex movements, a teaching-seeking and reproducible control system is adopted. More complex manipulators employ digital control systems, minicomputers, or microprocessor controlled systems.

The control system is most used by the latch plate, followed by the CAM drum. It is equipped with a number of cams, each CAM assigned to a movement axis, rotating drum movement one week to complete a cycle.

The special manipulator of injection molding machine is an automatic production equipment that can imitate some functions of the upper limb of the human body and can be automatically controlled to make it transport products or handle tools for production operations according to predetermined requirements. Injection molding manipulator is a machine specially equipped for the automation of injection molding production, which can reduce heavy manual labor, improve working conditions and safe production. It plays an important role in improving the production efficiency of injection molding machine, stabilizing product quality, reducing scrap rate, reducing production costs, and enhancing the competitiveness of enterprises.