How to choose a suitable single-axis injection manipulator?

Choosing a suitable single-axis injection manipulator is based on the properties of injection parts and the parameters of injection molding machine, matching the key indicators such as driving mode, stroke and load bearing of the manipulator, and taking into account the production requirements (such as mass production/small batch, whether it is necessary to expand functions) and field working conditions, taking into account the cost performance, convenient operation and adaptability to avoid "overqualified" or "equipment overload". Single-axis manipulator only realizes the vertical movement of Z axis, and the selection logic focuses more on the matching of core parameters, without considering multi-axis positioning. The following is a five-step selection method that can be directly landed, covering the matching of core parameters, the selection of expanding institutions, the screening of brands and configurations, with pit avoidance points and selection comparison tables attached, which is suitable for all small injection molding production scenarios.

Step 1: Core Basis-First, make clear two key basic data (the premise of type selection).

All selection actions are centered around the core parameters of injection molding parts and the basic parameters of injection molding machines, and accurate statistics/measurements are needed first to avoid the equipment being unusable due to the mismatch of subsequent parameters:

1. Key parameters of injection molded parts (directly determine the bearing and grasping mode of the manipulator)

Single-piece weight+total weight of nozzle: count the single-piece weight of finished product, add the nozzle weight (when picking the piece, it should be calculated according to the total weight), and record it as the actual grabbing weight (core index, directly corresponding to the rated load-bearing of the manipulator);

Product size/shape: measure the maximum length, width and height of the product (focusing on the height, which affects the picking height of the manipulator), and confirm whether the product is a regular part (pneumatic gripper is used for regular parts, and customized sucker can be provided for slightly irregular parts);

Posture requirements for taking parts: confirm whether the product sticks to the mold after mold opening and whether it needs to be turned over (if a side posture mechanism is needed for sticking the mold and a rotating mechanism is needed for turning over), and select the basic model if there is no special requirement.

2. Key parameters of injection molding machine (directly determine the stroke and installation mode of manipulator)

Clamping force of injection molding machine: Single-axis manipulator is only suitable for small injection molding machines of 100-500T (over 500T is medium-sized and large-sized injection molding parts, and double-axis/triple-axis manipulator is required), and the clamping force determines the installation and adaptation model of manipulator;

Mold opening stroke: measure the maximum mold opening stroke (cavity spacing after the mold is completely opened) of the injection molding machine, and the vertical effective stroke of the manipulator should be 5-10cm larger than the mold opening stroke (to ensure that it can go down to the bottom of the cavity to take parts);

Modulus of Capacity/height of the mold: confirm the height of the closed mold, match the height of the mounting bracket of the manipulator, and avoid interfering with the opening and closing of the mold after installation;

Pick-up space: check the pick-up space next to the fixed mold/moving mold of the injection molding machine. If there is no obstruction, select the standard model, and if there is slight obstruction, select the narrow single-axis manipulator.

Step 2: Match the core parameters-select three core indicators (the key to type selection).

According to the basic data of the first step, the three core indexes of the manipulator, namely, the rated load, the driving mode and the vertical effective stroke, are accurately matched, which is the key to determine whether the manipulator is suitable or not, and all indexes need to leave a safety margin of 1.2-1.5 times (to avoid the failure caused by the long-term full-load operation of the equipment).

1. Select rated bearing capacity according to "actual grab weight"

Core principle: rated load of manipulator ≥ actual grasping weight× 1.5 times safety margin (considering slight shaking and tooling weight when taking parts).

Recommended rated load-bearing adaptation product type for actual grab gross weight.

≤ 100g 200g Electronic precision small parts (such as connectors and earphone shells)

100-200g 300g small articles for daily use (such as toothbrush handle and switch button)

200-300g 500g packaging small pieces (such as bottle caps and crisper buckles)

300-500g 800g/1kg automobile mini-parts, slightly larger daily-use parts (such as clothes hanger accessories)

Note: The maximum rated load of single-axis manipulator is generally less than 1kg. If it exceeds 1kg, double-axis/triple-axis manipulator needs to be replaced.

2. Select the driving mode according to "production demand+weight"

Single-axis manipulator can be divided into pneumatic type and servo type, with no intermediate option. The core is selected according to production batch, picking accuracy and cost budget. Pneumatic type is the entry type, and servo type is the precision type, with obvious adaptability differences:

Contrast dimension pneumatic single-axis manipulator servo single-axis manipulator

Core drive cylinder+solenoid valve servo motor+screw rod

The picking accuracy is 1 mm (general) 0.1 mm (high accuracy).

The running speed is fixed (not adjustable) and stepless speed regulation (can match the injection rhythm)

Low cost (about 1/2-1/3 of servo) (high cost performance)

Adapt to the small batch, multi-variety and low-precision requirements of the scene (such as small toys and daily miscellaneous parts) and large batch, high beat and high-precision requirements (such as mass production of electronic accessories and bottle caps)

Adaptive weight ≤ 300g (it is easy to shake due to overweight) ≤ 1kg (it runs smoothly without shaking).

Core selection suggestion: ≤200g+pneumatic type in small batch (cost saving); ≥200g+servo type for mass selection (stable precision and high efficiency).

3. Select the vertical effective stroke according to the "mold opening stroke of injection molding machine"

Core principle: vertical effective stroke of manipulator = maximum mold opening stroke of injection molding machine+5-10cm safety margin.

Injection molding machine 100-200T: mold opening stroke is generally ≤30cm, and the effective stroke of manipulator is recommended to be 40cm；;

Injection molding machine 200-300T: mold opening stroke is generally 30-40cm, and the effective stroke of manipulator is recommended to be 50cm；;

Injection molding machine 300-500T: mold opening stroke is generally 40-50cm, and the effective stroke of manipulator is recommended to be 60cm；;

Note: The effective stroke of the manipulator is "the maximum distance that can move up and down", excluding the height of the mounting bracket. Please make sure to mark it as "effective stroke" instead of the total height when selecting the manipulator.

Step 3: Matching as required-expanding the mechanism and grasping fixture (fitting the actual production)

The basic single-axis manipulator can only move vertically up and down, so it is necessary to select the expanding mechanism and grasping fixture according to the product picking demand and production process, which is the key to adapt the manipulator to the actual production. All expanding mechanisms need to select the original factory accessories with the same brand as the manipulator (to avoid compatibility problems), and the core selection items are as follows:

1. Grab fixture (required, selected according to product shape)

Pneumatic gripper: it is suitable for regular hard parts (such as plastic shell, bottle cap and button), which are divided into two-finger gripper and three-finger gripper, and the gripper stroke (generally 10-30 mm) is selected according to the product width;

Vacuum sucker: it is suitable for soft parts, thin parts and easy-to-scratch parts (such as plastic film parts, precision electronic housings and curved parts). The size of the sucker (generally 5-20mm) is selected according to the product area, and a small vacuum generator is matched;

Customized fixture: it is suitable for slightly irregular parts (irregular grasping surface). Non-standard fixtures can be customized according to the product shape, and 3D drawings of the product should be provided in advance.

2. Attitude adjustment mechanism (optional according to requirements, to solve the product die-sticking/flipping requirements)

Side cylinder: The products that fit the die must be selected to realize 90-degree side flip, so that the products can be separated from the die from the die-attached state to avoid scratching the product/die when taking the parts, and the side angle can be fine-tuned (85-95);

Rotating mechanism (C-axis): it is suitable for the products that need to be turned over for blanking, and realizes 0-180 rotation, so that the products can be blanking according to the specified posture (such as text facing up and opening facing down), which can be divided into pneumatic rotation and servo rotation (pneumatic as the basic model and servo as the high-precision model);

Lifting fine-tuning mechanism: it is suitable for multi-variety production, and can fine-tune the picking height (5 cm). It is not necessary to disassemble the manipulator when changing the mold and changing production, saving debugging time.

3. Process supporting institutions (select as needed to realize simple process integration)

Simple nozzle cutting tool: it is suitable for the products whose nozzle is connected with the product and the nozzle is easy to break, and the nozzle is cut/broken in the process of picking up, replacing the manual nozzle, and supporting the fixed cutter or pneumatic cutter;

Blanking slideway/conveyor belt joint: realize the direct blanking to the conveyor belt/material frame after picking up the parts, without manual transfer, and match the scratch-proof slideway (such as flannelette) to avoid scratching the products during blanking;

Detection sensor: to meet the requirements of high precision, photoelectric sensor/pressure sensor is installed to realize that there is no part that can't be grabbed and the alarm can't be caught, so as to avoid the mold closing damage caused by missing parts.

Step 4: Details Screening-Pay attention to four key details (the core of pit avoidance determines the service life of equipment).

After matching the core parameters, attention should be paid to the details such as the material, installation mode, control system and protection level of the manipulator, which is the key to avoid faults in later use and reduce maintenance costs. The following four points should be selected:

Fuselage material: aluminum alloy profiles (lightweight, corrosion-resistant, easy to clean) are preferred, and ordinary carbon steel (easy to rust and heavy) is avoided. Brand accessories (such as Yintai and Shangyin guide rails) are needed for key stress parts (such as screw rods and guide rails);

Installation method: according to the structure of injection molding machine, choose machine side installation (the most mainstream, installed next to the moving die of injection molding machine) or machine top installation (suitable for the scene with narrow pickup space), and the installation bracket should have the function of height fine adjustment and horizontal fine adjustment (convenient and accurate positioning of pickup point);

Control system: pneumatic simple button control (easy to operate, suitable for ordinary workers), servo touch screen control (can set picking speed, stroke and delay, suitable for multi-variety production), and the control system needs to be equipped with emergency stop button, manual/automatic switching and fault alarm functions;

Protection level: There are many dusts and oil stains in the injection workshop, and the protection level of the manipulator should be ≥IP54 (dustproof and splash-proof), and the electrical components (such as solenoid valves and motors) should be provided with dust covers, and the lead screw/guide rail should be provided with dust covers (to avoid the jamming caused by dust entry);

Additional functions: the manipulator with mold protection function is preferred. If the parts are failed/missed, the manipulator will give an alarm and prevent the mold from closing, so as to avoid mold damage (pit avoidance point at the core of injection molding production).

Step 5: brand and configuration screening-both cost-effective and after-sales (long-term use guarantee)

Single-axis injection molding manipulator is an entry-level automation equipment, so it is not necessary to blindly pursue high-end brands. Domestic brands with high performance-to-price ratio (mature technology, convenient after-sales, and lower cost than imported ones by more than 60%) are preferred, and the core is selected according to brand reputation, after-sales guarantee and configuration materials. Specific suggestions are as follows:

Brand selection: priority is given to domestic mainstream brands of injection molding robots (such as Weili, Tuosida, Yizhimi and Tianxing), all of which have mature single-axis manipulator series, standardized accessories and easy replacement in the later stage; Avoid choosing products from small factories without brands (poor materials, high failure rate and no after-sales);

Configuration materials: focus on the brand of core accessories (guide rail, screw rod, motor and solenoid valve), give priority to brand accessories (such as Panasonic motor, Yadeke solenoid valve and Yintai guide rail), and avoid choosing miscellaneous accessories (short service life and easy failure);

After-sales guarantee: confirm whether the brand provides local after-sales service (the failure of injection molding manipulator requires timely maintenance, and the after-sales response in different places is slow), and whether it includes free installation and debugging, more than one-year warranty, and lifelong parts supply to avoid post-maintenance insecurity;

Cost budget: The budget of pneumatic single-axis manipulator (including gripper) is about 5,000-10,000 yuan, and that of servo single-axis manipulator (including gripper+rotating mechanism) is about 15,000-30,000 yuan. Choose according to production requirements, and do not blindly pursue high-priced configuration.

Key points of pit avoidance in the selection of single-axis injection molding manipulator (direct application to avoid selection errors)

Bearing without allowance: it is forbidden to choose rated bearing according to the actual grabbing weight, and 1.5 times safety allowance must be left, otherwise the long-term full-load operation of the equipment will lead to screw deformation and motor burning;

Error in stroke matching: It is forbidden to choose a manipulator whose effective stroke is less than or equal to the opening stroke of the injection molding machine, otherwise it will not be able to go down to the bottom of the cavity to pick up the parts, which will lead to the failure of picking up the parts;

Wrong selection of driving mode: selecting pneumatic type in mass production will lead to low precision and unstable operation, and selecting servo type in small batch production will lead to cost waste;

Non-original accessories: it is strictly forbidden to choose and match the expansion mechanism/fixture with miscellaneous brands, otherwise there will be compatibility problems (such as clamping jaws not moving and rotation angle deviation);

Neglect of mold protection: if the manipulator with mold protection function is not selected, the mold will be seriously damaged when the parts are missed, and the loss far exceeds the cost of the manipulator;

Out-of-range use: It is forbidden to use single-axis manipulator to adapt injection molding machines with a weight of over 500T and products with a weight of over ＞1kg. Forced use will lead to frequent equipment failures and even safety accidents.

Comparison table for rapid selection of single-axis injection molding manipulator (directly applied without complicated calculation)

The clamping force of injection molding machine actually grabs the total weight, recommends the driving mode, recommends the rated load, recommends the vertical effective stroke, and selects the necessary accessories as required.

100-200t ≤ 100g pneumatic 200g 40cm pneumatic gripper side posture cylinder

200-300t100-200g pneumatic/servo type 300g 50cm pneumatic gripper side posture cylinder+water nozzle tooling.

300-400t 200-300g servo 500g 50cm pneumatic gripper/sucker rotating mechanism+conveyor belt joint

400-500t300-500g servo-type 800g/1kg 60cm customized fixture profile+rotation+mold protection

summary

The logical core of the selection of single-axis injection molding manipulator is * * "Orientation of basic data, accurate matching of core parameters, detailed screening to avoid pits, matching and sticking production as needed", which focuses on the actual parameters of injection molding parts and injection molding machines, without considering the complicated multi-axis positioning, leaving a safety margin for all indicators, and selecting original accessories for the expanding organization. For a 100-500T injection molding machine and a small regular part * * of ≤1kg, accurate fitting can be realized by selecting the model according to this method; If the product weight is > ＞1kg, the clamping force of the injection molding machine is > ＞500T, or multi-dimensional picking/accurate setting is needed, it needs to be upgraded to a two-axis/three-axis injection manipulator.