Abstract: Comparison of manipulator end tools - purchase - experience: a brief explanation of some precautions in the purchase and use of manipulator end tools. The following content is compiled by Dishi.com for your reference. How to choose an end-of-arm tool (EOAT)

Today's injection molding processing companies attach great importance to the selection of injection molding machines or robots. However, few people have paid attention to the use of end-of-arm tooling (EOAT). In fact, EOAT is a very important part in the injection molding process.

If injection molding processing companies want their robots to be able to complete automated operations such as picking, placing, moving, handling and holding products, they must seriously consider choosing the end-of-end tooling system (EOAT) that is most suitable for their robots. .

The multi-joint manipulator and flexible end tool are connected together to economically move a variety of products.

Selection of EOAT

What kind of end-of-end tooling system (EOAT) can meet the needs of products and production? Usually, in order to select the most efficient EOAT system, injection molding processing companies must first comprehensively consider the opinions from the maintenance department, purchasing department and production department. At the same time, they should also consider other factors that affect the demoulding of the product. Specifically, these factors are:

1. In order to avoid unnecessary marks on the product, appropriate modifications to the mold should be considered. So that the product can be removed more easily. In order to make the product easy to release from the mold, the shape of the ejector pin is usually required to be appropriate. At the same time, the ejector pin must also have sufficient stroke so that it can push the product forward.

2. In the design of the product appearance, small chamfers are added to make it easier to demould.

3. Changing the material temperature can not only make the demoulding of the product easier, but also reduce the chance of marks or deformation on the surface of the product after demoulding.

After optimizing the design and modification of the mold, you must also understand the following questions:

1. How much pulling force or shearing force is required to remove the product?

2. Take the product out of the mold and put it into a container or on a conveyor belt. What operations can the robot provide? What supplementary actions does the EOAT system need to perform with the manipulator?

3. Can the robot hand reach the farthest point?

4. Is it necessary to install an extension arm?

5. Are there enough air/vacuum circuits and current input and output terminals on the manipulator so that it can be connected to the EOAT?

6. Can the robot reach the speed required by the molding cycle?

After fully considering the above conditions and factors, the EOAT system can be designed and selected. When choosing an EOAT system, you should also consider the following issues: the weight and texture of the product, whether the product has a suitable location for clamping, whether the product will be hindered by the mold when taking it out, the temperature of the product when it is ejected, The area that comes into contact with the tool when the product is placed on the conveyor belt. Finally, it should be noted that the total weight of the product and EOAT cannot exceed the load-bearing range of the robot.

Use of EOAT

Different types of end-of-end tools (EOAT) have different characteristics. For example, lightweight EOAT can meet the needs of the robot load range and can reduce equipment maintenance. Cost; Flexible, combined EOAT not only allows good adjustability of operation, but can also be used again in subsequent production; strong, rigid EOAT can firmly hold the product and has a longer service life; An EOAT made from standard parts is often less expensive than custom-made special tools, and its accessories are usually more readily available.

A variety of standard end tool components

Generally speaking, using vacuum suction cups to grab products is the cheapest method. Vacuum suction cups come in various varieties and can be made from different materials. Among them, suction cups made of elastomer and silicone rubber can operate at high temperatures. Suction cups made of silicone rubber are very suitable for grabbing products with rough surfaces; suction cups made of polyurethane are very durable. In addition, in actual production, if the suction cup is required to be oil-resistant, you can consider using materials such as polyurethane, nitrile rubber or vinyl-containing polymers to make suction cups.

Generally, in order to prevent the surface of the product from being scratched, it is best to choose a suction cup with a bellows made of nitrile rubber or silicone rubber.

When EOAT uses a vacuum suction cup (without clamp), it should be noted that the moving speed of the manipulator cannot be too high, otherwise a shear force will be generated on the suction cup, causing the product to twist rapidly It is easy to fall off during the process. In some cases, a clamp may be used to ensure safe delivery of the product. Taking into account the possibility of "product sticking to the mold", a clamp can usually be installed to solve this problem. When the surface area of ??the product is too small or the product is too heavy to use a vacuum suction cup, this problem can also be solved by using a clamp.

If the product has strict requirements on appearance, then the clamped part cannot be the outer surface. To solve this problem, a sensing circuit can be installed. After confirming that the clamp or suction cup has firmly grasped the product, the sensor will send a signal to the manipulator so that it can proceed with the next operation.

When the movement ability of the robot is limited and manual twisting or tilting is required to demold the product or move the product and EOAT out of the molding area, you can add a robot that can move the EOAT independently without relying on the robot. This problem can be improved by operating a special cylinder.

The end tool for in-mold labeling can complete three actions: In a limited space, EOAT first picks up and inserts the label, and then fixes the label in the mold. This operation reduces the size of the unit compared to static labeling units. The final action of EOAT is to remove the branded plastic bottle from the mold.

Generally, when injecting automotive parts, special care must be taken when handling products with Class A surfaces. In order to avoid scratches on its surface, the use of vacuum suction cups must be absolutely prohibited. At this time, you can consider installing a clamp made of acetal on the EOAT, which can effectively avoid scratching the surface of the product.

So, how to use EOAT in complex machining and molding processes? To illustrate this problem, let's take an example of "over-injection molding using nylon and rubber." In this example, a versatile end-of-arm tool (EOAT) is used to move the nylon product away from the operator. During the movement, the EOAT rotates at a certain angle. When it is adjusted to a suitable position, the nylon is placed into the mold cavity for over-injection with the rubber. After the injection molding is completed, the nylon/rubber products are taken out by EOAT. In this example, the molding cycle was greatly shortened by using this end tool, and it also provided operations that a single robot could not accomplish.

In the production of small products, the operation speed is often required, but the operating space is very small. In this case, the retracting vacuum arm (RVA) can be used to remove the small electronic parts from the mold. This EOAT is very lightweight and has a small cylinder that can first grab the product and then move it through automatic retraction.

Of course, for injection molding processing companies, if they have the time and ability, they can choose the parts and assemble the EOAT that suits their own production needs. If you are limited by time and technology, look for a full-service provider.