How to ensure the working efficiency of injection molding manipulator when installing fixture?

When installing the fixture, the working efficiency of the injection molding manipulator can be ensured by the following aspects:

First, optimize the installation accuracy and speed

Adopt precise installation tools and methods

Use high-precision positioning tools, such as positioning pins and positioning holes, to ensure that the fixture can be installed on the robot hand quickly and accurately. The diameter tolerance of the locating pin can be controlled within ±0.01-±0.03mm, which is closely matched with the locating hole, so that the fixture can be installed in one step and the adjustment time can be reduced.

For some fixtures and manipulator interfaces that need accurate alignment, laser alignment instrument can be used to assist installation. The laser centering instrument can accurately measure the deviation between the fixture and the manipulator interface, and the accuracy can reach 0.01 mm. By adjusting the fixture position, it can quickly align with the center line of the manipulator, which greatly improves the installation speed and accuracy.

Pre-assembly and modular design

Before installing the fixture, pre-assembly shall be carried out as far as possible outside the workshop or during non-working hours. Some parts of the fixture are pre-assembled, for example, the clamping jaw mechanism and the driving device are assembled into a module, so that when the fixture is installed on the manipulator, only the whole module needs to be installed once, which reduces the time for installing the parts on the manipulator one by one.

The fixture with modular design is also easy to replace and upgrade. If a module breaks down, it can be quickly disassembled and replaced with a new module without complicated maintenance of the whole fixture, thus reducing the downtime of the manipulator and improving the work efficiency.

Second, ensure the high efficiency of power transmission between fixture and manipulator.

Matching and Optimization of Power Interface

When the fixture is driven by pneumatic or hydraulic pressure, it is necessary to ensure that its power interface is completely matched with the power system of the injection manipulator. For example, the diameter and interface form of the air inlet and oil outlet of the air cylinder or hydraulic cylinder of the fixture should be adapted to the air path and oil path of the manipulator, and the sealing performance of the interface should be good to prevent leakage during power transmission.

Optimize the power transmission line to shorten the length of gas or oil circuit as much as possible. Too long gas path or oil path will increase pressure loss and response time. For example, put the air pump or oil pump as close as possible to the driving device of the fixture, reduce the elbows and resistance elements in the pipeline, so that the opening and closing action of the fixture can quickly respond to the control signal of the manipulator and improve the working efficiency.

Adjustment and adaptation of dynamic parameters

According to the load and action requirements of the fixture, the power output parameters of the injection manipulator are reasonably adjusted. For example, for the fixture that needs quick clamping and loosening, the pressure of the pneumatic system should be appropriately increased (but within a safe range), and the air pressure can generally be adjusted to 0.4-0.6MPa to speed up the action of the fixture.

At the same time, the flow of the power system should be controlled. By installing a flow regulating valve, the flow of gas or liquid can be accurately adjusted according to the action speed requirements of the fixture. For example, in the clamping action stage of the fixture, the flow rate can be appropriately increased, so that the gripper can quickly clamp the injection molded product; In the loosening action stage, the flow rate should be reduced reasonably to avoid the product from falling due to sudden loosening, and to ensure the stability and efficiency of the working process.

Third, ensure the reliability and stability of the fixture

Strict quality inspection and testing

Before installing the fixture, conduct a comprehensive quality inspection on the fixture. Including checking whether the parts of the fixture are damaged and whether the machining accuracy meets the requirements. For example, to check whether the surface roughness of the gripper meets the standard, the general gripping surface roughness Ra of the gripper should be less than 1.6μm, so as to ensure that the injection molded product can be gripped firmly and avoid the product slipping during gripping.

Test the function of the fixture, simulate the clamping, loosening, rotation and other actions in the actual working environment for at least 100 times, and check whether there is any abnormality in the repeated actions of the fixture, such as jamming and loosening. Only the fixture that has passed the strict test can be installed on the mechanical hand, so as to reduce the downtime and maintenance time caused by fixture failure during work.

Reasonable fixture balance design

After the fixture is installed, the balance of the whole manipulator system should be ensured. For some large or asymmetric fixtures, the mechanical hand should be stressed evenly during the movement by adding counterweight or adjusting the position of the center of gravity. For example, when installing a heavy side-taking fixture, an appropriate counterweight can be installed on the other side of the manipulator, so that the center of gravity of the manipulator is located on the rotation axis, which can reduce the vibration and shaking of the manipulator during the movement, improve the movement speed and positioning accuracy, and thus improve the work efficiency.

Fourth, improve the compatibility of fixture and manipulator control system.

Control system interface optimization

Ensure that the control interface of the fixture is compatible with the control system of the injection manipulator. For example, when the fixture is equipped with a sensor to detect whether the product is successfully grabbed, the signal type (such as digital signal or analog signal), voltage level (such as 24V DC) and communication protocol (such as Profibus, EtherCAT, etc.) of the sensor should match the control system of the manipulator.

Optimize the interface of the control system to reduce the signal transmission delay. High-speed communication cables can be used to connect the fixture and the control system of the manipulator. For example, optical fiber cables can be used instead of ordinary cables, which can significantly reduce the signal transmission time, enable the fixture to respond to the control instructions of the manipulator faster and improve the work efficiency.

Intelligent control program integration

According to the function and action requirements of the fixture, an optimized control program is written for the injection manipulator. For example, for fixtures with multiple grasping modes, an intelligent control program is written to enable the manipulator to automatically select the appropriate grasping mode according to the different shapes, sizes and positions of injection molded products.

Using the feedback function of the control system, the working state of the fixture is monitored in real time. When the fixture is abnormal, such as the clamping jaw is not completely clamped or loosened, the control system can give an alarm in time and take corresponding corrective measures, such as re-performing clamping action or adjusting the position of the fixture, so as to avoid affecting the work efficiency due to fixture failure.