How to optimize the program in the debugging process of injection molding manipulator?

This paper introduces the practical method of program optimization of injection manipulator in toy factory, which is done from six dimensions: path, speed, signal, delay, stability and appearance yield. All the parameters can be directly changed on site, regardless of theory.

First, make clear the optimization goal (toy factory values it most)

Products that do not bump, drop or scratch (safety+appearance)

Shortest cycle (no drag on the injection molding machine)

Stable operation: there is no alarm and no position drift for hundreds of modules continuously.

Simple maintenance: clear program logic and easy to remember parameters.

Second, the path optimization (the most critical, directly decide whether to hit the die or not)

1. Path principle: "near, straight, steady and avoiding"

Proximity: Pick-up point → Transition point → Drop-off point, with the shortest path, which reduces idle time.

Straight: try to be straight and turn less; The more turns, the greater the jitter and the more pieces are dropped.

Steady: low speed in the mold, steady in the air, and extremely slow loading.

Avoid: Keep away from the mold, thimble, hot nozzle and parting surface, leaving a safety gap of 20–50 mm.

2. Four key points that must be set (toy factory standard)

In-mold safety point (P00): Right above the center of the mold, 30–50 mm higher than the highest point of the mold, and the point that must pass when entering and leaving the mold.

Pick-up point (P01): 5–10 mm directly above the product, and the suction/clamping is lowered.

Out-of-mold standby point (P02): outside the mold, which does not affect the mold opening or block the safety door.

Drop point (P03): 5–10 mm above the assembly line/magazine, put it gently.

3. Path optimization action

Delete redundant intermediate points. If two points can be in place, don't use three points.

Enlarge the turning radius (R30-R50) to reduce jitter.

Multi-cavity: take the parts in sequence, and the paths do not cross to prevent collision.

Third, speed and acceleration optimization (anti-dropping, anti-scratching, cycle reduction)

1. Segment speed setting (gold parameter of toy factory)

form

Purpose of speed acceleration in action section

In-mold entry/exit 30%–50%–20%–30% anti-scratch and anti-dropping parts.

20%–30% and 10% anti-collision products and anti-dent.

70%-80%, 60%-70% in the air is fast and steady.

50%–60% and 40% do not tremble when going up or down.

Drop/loosen the parts by 10%–20% and 10% with care and no scratches.

2. Optimization points

Don't go all the way at high speed: large jitter, many pieces falling off and scratches on the product.

Don't slow down the whole process: the cycle is long and the efficiency is low.

Acceleration is better to be small than large: toys are thin-walled and light, and if they accelerate too hard, they will fall off.

Fourth, signal and interlock optimization (collision avoidance machine, misoperation prevention)

1. Core signal timing (must fit together)

Injection molding machine: after the mold is opened → the ejector pin is in place → signal the manipulator.

Manipulator: after receiving the signal → enter the mold → take the part → exit the mold.

Manipulator: completely quit → send "Pick-up Complete" to the injection molding machine.

Injection molding machine: receiving signal → locking → injecting glue.

2. Signal optimization

Cancel redundant signals: only the necessary eight signals (mold opening, safety door, part taking, no manipulator in the mold, emergency stop, alarm, ejector pin withdrawal, and part placing) are reserved.

Signal delay precision:

After the mold is opened → the manipulator enters: 0.2-0.5s (when the mold is stable, it will not grab the signal).

Pick-up completed → Injection molding machine: 0.1s (no cycle delay)

Interlocking must be hard:

The manipulator is in the mold → absolutely prohibit mold locking.

The safety door is not closed → the manipulator must not enter the mold.

Five, delay optimization (to solve the problem of parts, die, position is not allowed)

1. Time delay commonly used in toy factories (directly applied)

Holding time of suction parts: 0.3-0.5s (ensure the suction is firm, and 0.5s for thin-walled parts).

Delay of blowing/releasing parts: 0.2s (put them in place lightly and then loosen them).

Time delay of ejector pin withdrawal: 0.2-0.3s (to prevent ejector pin from scratching the product)

In-mold residence time: the shortest, and exit immediately after taking it.

2. Optimization principle

The longer the delay, the better: too long the delay period, too short the parts are dropped.

Set the middle value first, and then gradually reduce it until it does not drop parts or stick to the mold.

Six, stability optimization (continuous hundreds of modules without problems)

1. Position compensation

If there is slight drift (≤0.5mm) after continuous operation, turn on automatic position compensation (most manipulators have this function).

Multi-cavity: each cavity is fine-tuned independently to ensure the consistency of taking parts.

2. Jitter suppression

Check whether the manipulator is firmly fixed (anchor, bracket, connecting screw)

Clean guide rail, rack and gear, and add a little lubrication.

Reduce the acceleration of high-speed section and reduce the start-stop impact.

3. Countermeasures for dropping parts/sticking dies

Vacuum sucker: suction force-0.06~-0.08MPa, blowing off, anti-sticking mold.

Fixture: pressure 0.3–0.5 MPa, soft rubber pad, anti-pinch mark.

Product die sticking: extend the blowing time, adjust the position of ejector pin and polish the die.

Seven, cycle optimization (don't drag the injection hind legs)

Measure the manual picking cycle first, and the manipulator target is less than or equal to the manual cycle.

Optimization sequence: first ensure safety and stability → then raise speed → finally squeeze cycle.

Common bottlenecks:

Slow in-mold speed → appropriately increased to 40%–50%.

Slow loading → Shorten the waiting time before loading.

Long signal waiting time → Check whether the injection molding machine signal is delayed.

Eight, the acceptance criteria after program optimization (toy factory production line)

Continuous 200 molds: no mold collision, no missing parts, and no product scratch/pinch.

The success rate of picking is ≥99.5%.

Stable cycle, faster or even than manual operation.

The program parameters are recorded clearly, and die changing can be called quickly.

Nine, toy factory common optimization cases (direct copy)

Small thin-walled toys: low suction, low speed, short delay and light handling.

Multi-cavity (4/8 cavity): the paths do not cross, the picking sequence is fixed, and each point is fine-tuned.

Take the material head+product together: take the product first, then take the material head, and separate the paths to prevent the material head from scraping the product.