Robot offers a solution for complex products with precise finishing
ZEST carried out this project on behalf of Alligator Plastics, also based in Eindhoven, manufacturer and developer of plastic injection molded products.
ZEST
ZEST markets innovative systems and devices for its customers. ZEST can turn ideas into reality through business development, development and financing. The development consists of the use of HMI, design and mechatronics, always with a view to the greatest possible success of the device in the market. Special machines are mainly built for the Dutch manufacturing industry, where ZEST uses years of experience to make customer production better, more efficient and therefore cheaper.
Accessible
ZEST had originally considered using cobots for this project. However, through discussions with Yaskawa, ZEST came to the conclusion that a standard robot was better for this purpose instead of one of the cobots in the range. Preference was given to a local robot manufacturer and another customer had experience with Yaskawa robots. “Yaskawa turned out to be very accessible,” says Cyrille Gradus, Commercial Director at ZEST. “That's why we chose Yaskawa.”
Alligator Plastics produces, among other things, injection molding products for the energy supply, specifically for green energy, for one of its customers. During the development of a new product range, the desire arose to mount a metal plate, equipped with a screw thread, in the product to guarantee a sufficiently firm fixation of the end product. ZEST was approached for this mechanization process and it was decided, due to the complexity of the product, the required speed of positioning and the difficult position where the metal had to be placed, that the best option was to do this using 6-axis robots.
Complex system
“It has become a rather complex system. The finishing position of the robot goes quite deep into the product, so we've equipped it with a long gripper," says Rens van Hulst, Automation Software Engineer at ZEST. "We used a vision system initially to let the components pass under the camera on a conveyor belt. The robot was stationed at the end of the conveyor belt to pick up the components and place them into the product.”
In practice, it turned out that products often got stuck on the conveyor belt, and the tilting of the products didn't always go smoothly. Eventually, we now use a vibrating filler, ensuring that the products always end up in the same spot," continues Van Hulst. "This way, we only need to teach the robot one position. The robot receives a signal, and then it picks it up, which is a much better solution.”
Vibratory filler
With the original system there was an area in which the robot chose a picking position based on the camera. This moved with the speed of the conveyor belt. “Now with the final system, the plate comes out of the vibratory filler and our system ensures that it is pushed in a certain direction so that it always remains in the same position. Then we send a signal to the robot and it picks it up. On the other side, where the product has been delivered from the injection molding machine, the plate that has been removed from the conveyor belt will be placed,” says van Hulst. There are two deposit positions and based on the deposit position that is requested, the robot will go left or right. This happens four times during each injection molding round.
Light products
For this system, ZEST has chosen the Yaskawa GP7 handling robot, a fairly small variant because it works with light products weighing a few hundred grams. One robot is used per machine, but three different machines have been delivered to the customer, so a total of three GP7 robots are used.