How to install a suitable injection manipulator to pick up the parts in the beverage bottle processing factory?

When installing an injection molding manipulator to pick up the parts, the beverage bottle processing factory should combine the model of injection molding machine, the specifications of beverage bottles (such as PET bottle blanks and HDPE bottle bodies), the production rhythm and the automation requirements to ensure the high efficiency and stability of picking up the parts and reduce the damage to the molds and products. The following are specific installation points and precautions:

I. Pre-selection: Matching production demand

According to the parameter selection of injection molding machine

Tonnage and stroke: the tonnage of the injection molding machine (such as 50T-500T) determines the load capacity of the manipulator (usually, the weight of the bottle blank/bottle body is relatively light, so the load of 5-20kg can be selected); The mold opening stroke of the injection molding machine should match the "back and forth telescopic distance" of the manipulator (to ensure that the manipulator can go deep into the mold to take the parts).

Mold opening and closing speed: high-speed injection molding machine (such as bottle blank production cycle of 3-5 seconds) needs to be equipped with high-speed traversing manipulator (traversing speed ≥1.5m/s) to avoid that the picking speed cannot keep up with the production rhythm; Ordinary servo manipulator can be selected for low-speed machine.

Selection according to product characteristics

Bottle blank/bottle shape:

Long and thin bottle blanks (such as mineral water bottle blanks) need multi-station clamps (grab 4-8 pieces at a time), and cooperate with the side posture group (adjust the angle of taking parts) to prevent them from falling askew when taking parts;

Special-shaped bottles (such as beverage bottles with handles) need customized copying fixtures (silicone or PU materials to avoid scratching the bottles) to ensure stable grasping.

Product temperature: The temperature of the bottle blank that has just been demoulded is relatively high (about 80-120℃), so it is necessary to choose a high-temperature resistant fixture (such as metal clamping jaw+thermal insulation coating) or an air cooling device (synchronous cooling when taking the parts).

Second, the installation position and fixed specification

Installation position determination

Conventional installation: the manipulator column is fixed on the side or above the fixed template of the injection molding machine, so as to ensure that the movement track of the traverse arm avoids the injection molding machine pull rod, safety door and peripheral equipment (such as conveyor belt), and reserve at least 50cm operation space.

Special scene: If multiple injection molding machines are produced side by side, gantry manipulator (cross-machine picking) can be selected and installed on the ground behind the injection molding machines, so that multiple machines can share through the track, but the levelness of the track (error ≤0.5mm/m) should be ensured to avoid running jam.

Fixation and calibration

Fix the manipulator base on the cement floor (or the body of injection molding machine) with expansion bolts, and check the levelness of the base after tightening (calibrated with a spirit level, with an error of ≤1mm/m) to prevent displacement caused by vibration during operation.

Calibrate the relative position of manipulator and mold;

The "dropping pick-up point" of the manipulator needs to be aligned with the position of the product in the mold (deviation ≤0.5mm), and the manipulator can be manually controlled to move, and the coordinates are marked with a marker pen and then entered into the system;

The horizontal arm is parallel to the parting surface of the mold, so as to avoid the clamping jaw colliding with the mold cavity when taking the parts (especially for the precision bottle blank mold, the collision will easily lead to the wear of the cavity).

Third, fixture design and debugging of picking action

Fixture selection and installation

Claw type:

The bottle blank is usually opened and closed by pneumatic gripper (driven by air cylinder), and the material of the gripper is wear-resistant silicone (to avoid scratching the thread of the bottle mouth) or metal (with buffer spring to prevent the clamping force from being deformed by excessive pressure);

A vacuum sucker can be used for the lightweight bottle body (the diameter of the sucker needs to be matched, such as a silica gel sucker with a diameter of 10-20mm, and the suction force is adjusted by a vacuum generator to ensure that it is tightly sucked and does not fall off).

Fixture installation should be firm: the gripper/sucker and the manipulator end effector (flange) are fixed by screws, and anti-loosening gaskets are installed to avoid falling off during high-speed movement.

Optimization of picking action process

Standard action flow: the mold opening signal is triggered → the manipulator descends → the gripper closes (taking parts) → the manipulator ascends → the gripper moves horizontally → the gripper opens (putting parts) → resets. It is necessary to set the speed and time of each link through the manipulator control system (such as PLC) to ensure synchronization with the mold opening and closing rhythm of the injection molding machine (for example, the manipulator begins to descend 0.5 seconds before the mold opening is completed, reducing the waiting time).

Debugging of key parameters:

Descending speed: slow down when approaching the mold (for example, from 500mm/s to 100mm/s) to avoid impacting the product;

Gripping force: adjust according to the product weight (for example, 10g bottle blank, the gripping force is about 0.5-1kg), which can be realized by adjusting the air pressure (pneumatic gripper) or vacuum degree (suction cup), and observe whether the product is deformed or falls off when trying to grasp;

Placement position: aim at the center of the conveyor belt (or magazine), and release of the gripper/sucker will be delayed for 0.2 seconds during placement to prevent the product from deviating when falling.

Fourth, signal docking and automation linkage

Signal interaction with injection molding machine

Connect the signal lines between the manipulator and the injection molding machine (such as the signal of mold opening in place, the signal of part taking completion, and the emergency stop signal), and ensure that the manipulator can take parts only after the injection molding machine opens the mold in place, and the injection molding machine can close the mold only after the part taking is completed, so as to avoid equipment collision caused by "grabbing action".

Install safety interlock device: if the manipulator is not reset, the injection molding machine cannot close the mold; If the injection molding machine stops suddenly, the manipulator will stop immediately to prevent accidents.

Linkage with downstream equipment

After picking up the parts, the products should be sent to the conveyor belt (or testing equipment), and the height of the manipulator should be adjusted to be flush with the conveyor belt (the drop is less than or equal to ≤10cm) to avoid scratches or deformation when the products fall.

If it is matched with automatic inspection (such as roundness inspection of bottle mouth), the action of "rotation inspection" can be added before placing (the manipulator drives the product to rotate and cooperate with the visual sensor to detect), and the unqualified products can be placed in the waste box separately through the manipulator.

Five, safety and maintenance points

Safety protection

A protective fence (height ≥1.2m) shall be installed in the manipulator work area, and a safety grating shall be installed at the fence door, so that the equipment shall be stopped immediately when personnel enter;

One emergency stop button should be set next to the manipulator and the injection molding machine, and the logo should be clear to ensure quick operation in case of emergency.

daily maintenance

Check the pneumatic system every day: whether there is air leakage in the air pipe, drain water from the filter (to prevent water from entering the cylinder and causing rust), and fill the piston rod of the cylinder with lubricating oil;

Clean the surface of the gripper/sucker every week (especially the scraps left in the bottle blank) and check the wear of the vacuum sucker (replace it in time after aging to avoid the decrease of suction);

Calibrate the movement accuracy of the manipulator every month (if the repeated positioning error exceeds ±0.1mm, it needs to be compensated by the control system), check the lubrication of the guide rails of each shaft, and add special guide rail oil.

summary

The core of installing the injection manipulator in the beverage bottle processing plant is "accurate matching+efficient linkage" —— from parameter adaptation during selection, to position calibration during installation, and then to detail optimization of action debugging, it is necessary to focus on the goal of "taking parts quickly, putting parts stably, and not damaging products and molds", and at the same time realize automatic cooperation with injection molding machines and downstream equipment through signal docking, and finally improve production efficiency (usually 30%-50% can be reduced)