What kind of injection manipulator can the washing machine shell injection processing factory choose?

The shell of washing machine is a large-scale injection-molded part, which is large in size and heavy in weight, and the surface is usually required to be smooth and flawless. Therefore, when selecting the injection manipulator, it is necessary to focus on load capacity, abduction length, motion accuracy and stability. The following are some suggestions on manipulator selection for washing machine shell injection molding factory, covering types, configurations, core parameters and adaptation points:

I. Analysis of core requirements based on product characteristics

1. Product parameter reference

Size: The shell size of common washing machines is about 800mm×600mm×1200mm (length× width× height), and the unit weight is 10-15kg(ABS or PP material).

Structural features: the surface is flat, the edge has flanging, and some models have installation holes or buckle structure, so it is necessary to avoid deformation or scratch when taking parts.

Production lead time: low and medium speed production is the mainstay (15-30 seconds per mold), but the stability of continuous operation (such as 24-hour uninterrupted production) should be ensured.

2. Matching requirements of injection molding machine

Clamping force: Generally, a 1000-2000 ton injection molding machine (such as Izumi UN2000) is used, the template size is ≥1200mm×1200mm, and the mold opening stroke is 800-1000mm.

Installation location: horizontal injection molding machine is the main part, and the manipulator needs to take parts horizontally from the side to avoid interference with the mold ejection mechanism.

Second, the manipulator type and structure selection suggestions

1. Five-axis or six-axis servo manipulator is preferred.

Type core advantage adaptation scenario reference cost

Five-axis servo manipulator-the arm span is 1.5-2.5m, the load is 20-50kg, and the repetitive positioning accuracy is ±0.2mm；;

-It is equipped with pitch (R1) and rotation (R2) joints, which can flexibly adjust the picking angle to avoid the shell edge colliding with the mold. Conventional washing machine shell (without complicated internal ribs) needs to be turned over and placed on the conveyor belt. 180,000 to 300,000 yuan

Six-axis multi-joint manipulator-6 degrees of freedom, arm span up to 3 meters, load 30-80kg, positioning accuracy ±0.1mm；;

-Humanoid arm structure, which can complete complex trajectory movement (such as taking out the shell with inverted button from the deep cavity of the mold). High-end washing machine shell (such as curved surface modeling or embedded metal parts) needs high-precision assembly. 350,000 to 600,000 yuan

2. Avoid choosing three-axis manipulator.

Three-axis manipulator (XYZ axis) can only move in a straight line, which can't meet the multi-angle demand of washing machine shell, and it is easy to cause the following problems:

Scratched the surface of the product due to fixed angle when taking the parts;

It is impossible to avoid the mold thimble or hot runner parts, and there is a risk of interference.

Iii. Key points of core configuration and function customization

1. Design of end effector (fixture)

Fixture type:

Vacuum suction cup combination: large-area silica gel suction cups (100-150mm in diameter, 4-6 in number) are uniformly distributed on the top surface of the shell to ensure the adsorption force ≥20kg (safety factor ≥1.5 times);

Auxiliary mechanical claws: 2-4 soft claws (such as nylon) are added to the bottom edge of the shell to prevent the parts from falling when the suction cup leaks.

Anti-deformation design:

A flannel buffer layer is added to the surface of the suction cup to avoid leaving an indentation during adsorption;

The clamping jaw pressure can be adjusted (0.1-0.3MPa) to prevent the shell from deforming due to excessive clamping force.

2. Drive and control system

Servo motor configuration:

The power of the X-axis (horizontally moving) motor is ≥2kW, so as to ensure that the running speed is ≥ 0.8m/s under 20kg load;

The Z-axis (vertical lifting) motor has the function of locking the brake to prevent the manipulator from falling when power is cut off.

Control system:

Adopt PLC+touch screen combination (such as Siemens S7-1200), support parameter storage (more than 20 groups of product programs can be saved), which is convenient for quick switching when changing molds.

3. Detection and safety system

Vacuum detection: install a pressure sensor to monitor the vacuum degree of the suction cup in real time (alarm and stop when it is lower than-60kPa) to prevent the parts from falling off during the picking process.

Collision protection:

An elastic buffer is installed at the end of the mechanical arm to absorb the impact force during collision;

An infrared light curtain (detection range ≥ 3m) is set in the operation area, and the speed will be automatically reduced to 0.3m/s when people approach.

IV. Integration Scheme with Peripheral Devices

1. Assembly line docking

Conveyor belt design:

The width is ≥ 1.2m, the speed is 0.5-1m/s, and the surface is covered with non-slip rubber to prevent the shell from sliding;

The placement position of the manipulator should match the height of the conveyor belt (usually 800-1000mm above the ground) to ensure the smooth placement of parts.

2. Deburring and detection linkage

If the edge of the shell needs to be deburred, a floating grinding head (such as a pneumatic sandpaper wheel) can be integrated on the mechanical hand, and the edge grinding can be completed synchronously after taking the parts;

Optional visual inspection system (such as KENS VR-3000) can be used to detect defects such as lack of material and flash, and the detection accuracy is 0.3 mm..

V. Supplier Selection and Acceptance Criteria

1. Key evaluation indicators

Case experience: the supplier is required to provide at least three cases of the manipulator project of washing machine shell to verify its load capacity and stability (such as continuous operation for 8 hours without failure).

Simulation ability: It is necessary to provide a simulation video of the picking movement of the manipulator, focusing on the following scenes:

Obstacle avoidance trajectory when taken out of the mold;

Angle control when placed on conveyor belt (error ≤ 1).

2. Acceptance test items

Load test: run it for 1000 times under 20kg load, and detect the jitter of the manipulator (vertical direction ≤ 0.5mm);

Beat test: run continuously for 24 hours according to the set cycle (e.g. 20 seconds/module), and the success rate of picking should be ≥ 99.8%;

Noise detection: The noise at a distance of 1m from the manipulator is ≤78dB, which meets the workshop environmental protection standards.

VI. Reference of Cost and Return on Investment

1. Cost composition (taking five-axis servo manipulator as an example)

Mechanical arm body: 120,000-180,000 yuan (accounting for 60%);

Fixture and sucker system: 30,000-50,000 yuan (accounting for 15%);

Control system and detection device: 30,000-40,000 yuan (accounting for 15%);

Installation, debugging and training: 20,000-30,000 yuan (accounting for 10%).

2. ROI calculation (taking a production line as an example)

Manpower saving: replacing two operators (annual salary of 80,000 yuan/person), saving 160,000 yuan annually;

Efficiency improvement: automatic picking is 3-5 seconds faster than manual work, and the annual production capacity is increased by about 50,000-80,000 pieces (calculated by unit price 10 yuan, the annual income is increased by 500,000-800,000 yuan);

Return period: usually the cost can be recovered in 10-14 months, which is suitable for mass production scenarios.

summary

The servo manipulator with "large load, long arm extension and high flexibility" should be selected for the injection molding of the washing machine shell, and the five-axis or six-axis structure should be given priority. By customizing the vacuum sucker fixture, anti-deformation design and intelligent inspection system, the picking efficiency and product yield can be ensured. It is suggested that manufacturers should simultaneously consider the integration scheme with conveyor belt and testing equipment when selecting models, so as to realize the automation of the whole process from picking to sorting, reduce labor costs and improve the stability of production lines.