How to choose a suitable fixture for injection molding manipulator according to injection molding products?

Choosing a suitable EOAT for injection molding products requires comprehensive consideration of product characteristics, production lead time and equipment parameters. The following are specific selection guidelines:

1. Select fixture type according to product appearance and material characteristics.

Appearance-sensitive products: If the product has strict appearance requirements (such as automobile A-class surface interior decoration, electronic product shell, etc.), vacuum suction cups or rigid fixtures should be avoided to avoid scratching or leaving suction marks. It is suggested to choose a clamp made of soft materials such as acetal to ensure reliable grasping and protect the surface smoothness of the product.

Brittle or ultra-thin products: For ceramic substrates, glass or ultra-thin plastic parts, it is necessary to avoid product damage caused by rigid impact. It is suggested to choose elastic clamping (such as spring/silica gel pad to provide pre-pressure) or vacuum adsorption (non-contact clamping) to prevent the product from cracking or deformation.

Special products with difficulty in demoulding: For products with many top blocks or dermatoglyphics on the surface, it is easy to fall off simply by using suction cups, and it is easy to deform when using holding tools. The fixture of "sucker+retractable hook" can be used, and the product can be hooked out of the top block by the hook, and the sucker is responsible for fixing the anti-skid, thus realizing zero alarm and full automatic demoulding.

2. Match the fixture according to the size, weight and shape of the product.

Weight and volume evaluation: when the surface area of the product is too small or the weight is too large, the vacuum sucker may not provide enough adsorption force, so the mechanical clamp should be used for grasping. At the same time, the selection of fixture must match the load capacity of manipulator, and it is usually required that "product weight+fixture weight" is multiplied by 1.5 times the safety factor to prevent the equipment from overloading for a long time.

Shape and structure adaptation: there is no universal fixture, and it must be customized according to specific products. For example, when the nozzle position of injection molded parts is low or there is a special gap, it is necessary to choose a widened fixture or a fixture with a limit clip to ensure that the product can be accurately clamped and prevent it from tilting or rotating when it is taken out.

Three, combined with the production rhythm and accuracy requirements

Response speed matching: For high-speed injection molding machine (molding cycle ≤5 seconds), the response time of fixture is very important. It is recommended to equip vacuum sucker with quick response valve first, because pneumatic clamping/releasing usually takes 0.1–0.5 seconds, which can effectively avoid slowing down the overall production cycle.

Positioning accuracy requirements: the positioning accuracy of the fixture for general plastic parts is within ±0.1mm; However, for medical consumables, optical lenses or precision electronic micro-accessories, it is necessary to choose special precision fixtures to press the repeated positioning accuracy to the level of ±0.05mm or even ±0.02mm to ensure the assembly fit.

Fourth, consider the die changing frequency and automation matching.

Demand for quick die change: If the same machine needs to switch production dies frequently, it is recommended to configure manual or automatic quick change fixture module. The module can integrate gas circuit and sensor signal, realize rapid replacement and high-precision positioning of fixture, avoid the tedious debugging of position and rewiring, and greatly shorten the production preparation period.

Complex action requirements: For in-mold labeling and other scenes requiring multi-step operations such as picking, inserting and fixing, a special in-mold labeling terminal tool needs to be customized to reduce the device size and improve the label fitting quality.