How to customize your own special manipulator for injection molding machine according to different injection molding products?

The core of customizing the special manipulator for injection molding machine is to quantify and match item by item according to the path of product and mold parameters → axis number and structure → load and stroke → precision and beat → end effector → safety and integration, and then verify and iterate through the prototype.

First, do the "three lists": quantify the demand into hard indicators.

Product list

Weight of single piece+total weight of nozzle (to be superimposed when taking the whole), with a margin of 20%.

Maximum length, width, height, wall thickness, whether there is undercut/deep cavity/insert.

Appearance requirements (whether pinch marks are allowed), dimensional tolerance, and repeated positioning accuracy requirements.

Pick-up posture: close to the mold, need to flip/side posture, need secondary positioning (such as two-color/in-mold insert).

Production lead time: single-mode cycle and target capacity (times/hour).

List of molds and injection molding machines

Clamping force → corresponding manipulator load level (small/medium/large).

Rod spacing (Corinthian column spacing) → arm width must be less than this value and leave a gap.

Die opening stroke, template size, ejection distance → match Z axis and drawing stroke.

Die type: two plates/three plates/overlapping die/hot runner → determine single arm/double arms and action sequence.

Site and process list

Installation space, interference (safety door, peripheral equipment).

Process expansion: whether it is necessary to combine detection, labeling, assembly and packaging.

Environment: cleanliness level (such as Class 100,000), temperature and humidity, dust/corrosiveness.

Second, the number of shafts and structural selection: determine the scheme according to the complexity of the action.

form

Axis number/structural core competence Typical products are not applicable to the scene cost range.

Single/two-axis (diagonal arm/horizontal walk) straight-line pick and place, high-speed and low-cost bottle caps, electronic small parts, regular daily necessities die-sticking, need to flip/low side posture (10,000-50,000).

Three-axis servo (XYZ) can be used for lateral posture/overturning, and it can be used for general household appliances and medium-sized parts with complex posture and deep cavity inversion (50,000-150,000).

Five-axis (XYZ+R1/R2) pitch+rotation, interference-free two-color/multi-color, with inserts, ultra-precision curved surface parts/extremely complex trajectories (150,000–300,000).

Six-axis multi-joint all-space posture, obstacle avoidance, strong deep cavity inversion, complex curved surface, high-speed beat of in-mold assembly and high load (300,000-600,000).

Tau-head/frame long stroke, heavy-load stable strip parts, large exterior decoration parts with small space, light load and medium height (200,000-400,000).

Quick decision:

Pick-up only, no posture → three axes.

Stick to the mold, need to flip/side posture → three-axis side posture or five-axis side posture.

Two-color/in-mold insert, secondary positioning → five-axis/six-axis+vision.

Long/large pieces → tauren/frame type.

3. Matching of key parameters: travel, load, accuracy and beat.

1) Travel design (full motion path must be covered)

X axis (horizontal): ≥ template width+blanking area width+safety clearance (≥50mm).

Z axis (up and down): ≥ mold opening stroke+product height+safety clearance (≥50mm).

Drawing stroke: ≥ ejection distance+gap between product and mold cavity (≥20mm).

Deflection compensation and double guide rails are needed for long travel to avoid jitter.

2) Load and drive

Payload = product+fixture+allowance (≥1.2 times).

Example: product 3kg+fixture 1kg → selection ≥4.8kg.

Servo+synchronous belt for light load and high speed; Servo+ball screw for heavy load and high precision.

3) Accuracy and Beat

Ordinary parts: 0.1 mm.

Precision parts (electronic casing, medical treatment): ≤ 0.05 mm.

Ultra-precision (in-mold assembly): ≤±0.02mm, with vision and high-precision servo.

Beat target: single cycle time ≤ injection molding machine cycle; The high-speed line needs **≤3 seconds/time * *.

Fourth, the end effector (fixture/sucker) customization: determines the success or failure of grasping.

1) Selection of clamping mode

form

Material/structure points for attention in product feature recommendation scheme

Flatten NBR/silica gel of thin plate/box cover vacuum sucker group, and evenly distribute multiple suckers to avoid insufficient negative pressure; Food/medical food grade

Special-shaped/concave-convex parts are customized with mechanical jaws of nylon/PEEK/stainless steel, which are elastically limited to prevent pinch marks; Long-stroke gripper for deep cavity

Compensation for thermal deformation of high temperature resistant jaws/suction cups fluororubber/superalloy for high temperature parts (> 80℃)

Soft clamping jaw of precision parts+vacuum polyurethane/silica gel, lightly pressed without scratches.

Insert/multi-color positioning fixture+clamping jaw stainless steel/PEEK, quick release and repeated positioning ≤ 0.05 mm.

2) Key points of fixture design

Quick change structure: the change time is ≤5 minutes.

Avoid interference: fixture height ≤ mold opening height, edge fillet transition.

Anti-dropping parts: multiple suction cups/claws, with anti-dropping detection (proximity switch/pressure sensor).

Cleanliness requirements: no oil stain, easy to clean, food/medical stainless steel+passivation.

V. Integration of control system and linkage: Let the manipulator "understand" the injection molding machine.

1) Interface and signal

High-speed I/O(≤10ms delay), realizing mold opening → taking parts → closing and interlocking.

Ethernet/Profinet/EtherCAT docking PLC, vision and detection equipment.

Reserved expansion I/O, leaving interface for subsequent labeling/assembly.

2) Program and trajectory

Standard flow: standby → descending → grabbing → ascending → translating → placing → resetting.

Complex path: off-line programming+simulation to avoid interference.

Key signals: the parts are taken and put, and the abnormal alarm is interlocked with the injection molding machine.

VI. Safety and Protection: Compliance and Stability

Safety fence, grating and emergency stop button are linked with the safety circuit of injection molding machine.

Dust-proof/waterproof/anti-corrosion: arm seal, protection grade IP54+; Dust environment with protective cover.

Overload/overtravel/collision protection: dual protection of servo alarm and mechanical limit.

Clean scene: dust-free lubrication, anti-static, easy disinfection, in line with GMP/Class classification.

7. Prototype Verification and Mass Production Iteration: Avoid on-line rollover

Prototype test

100,000 life tests, recording the beat, accuracy and failure rate.

Run at full load and verify vibration and positioning drift.

Full-condition interference simulation (mold opening limit, maximum product size).

Mass production optimization

Adjust the acceleration and deceleration curve according to the actual beat to reduce the impact.

Optimize the adsorption force/clamping force of fixture, and reduce parts dropping and clamping marks.

Add fault self-diagnosis and remote operation and maintenance functions.

Eight, typical scene customization example

Small daily necessities (bottle cap, 0.5kg, beat 5 seconds/time) scheme: two-axis traverse servo, sucker grasping, x = 800–1200 mm, z = 500–800 mm, accuracy ±0.1mm, cost 1–30,000.

Medium-sized parts of household appliances (3kg, side posture required for die sticking) scheme: three-axis servo side posture, customized gripper, x = 1200–1800 mm, z = 800–1200 mm, accuracy ±0.05mm, and cost 50–100,000.

Two-color/in-mold insert (0.5kg, secondary positioning ±0.05mm) scheme: five axes+visual positioning, elastic positioning fixture, accuracy ±0.02mm, cost 150,000-250,000.

Scheme of large exterior decoration (10kg, long strip, 3000T injection molding machine): tauren five-axis, heavy-duty gripper, X=2370mm, Y=3000mm, Z=4500mm, load ≥50kg, cost 200,000-400,000.

Nine, landing list (directly sent to suppliers)

Product: weight, size, tolerance, posture, whether it is inserted/inverted.

Injection molding machine: clamping force, pull rod spacing, mold opening stroke, template size and ejection distance.

Site: installation space, beat target, cleanliness level and peripheral equipment.

Function: Do you need to test/label/assemble/change quickly?

Budget: scope and priority (accuracy/efficiency/cost)

Bottom line: First, quantify the product and mold parameters, then select the shaft number and structure, match the stroke/load/precision/beat, customize the end effector, complete the linkage and safety, and finally verify the prototype iteration, so as to make an injection manipulator that is completely suitable for its own production line.