A secure grip on the gearbox - handling of a gear wheel

The automotive supplier LINAMAR SEISSENSCHMIDT Forging is breaking new ground for the machining of a transmission wheel: A cobot was placed between two machining machines and now works towards the machine operator. The robot takes over the transport of the component between the first and the second processing machine as well as to the needle embossing. ZIMMER Group ensures a secure grip during transport with its gripper solution for robot-based handling.

Against the background of electromobility, the perspective of the automotive industry is playing an increasingly important role, especially for its suppliers: the LINAMAR SEISSENSCHMIDT Forging Group (LSF) is already well positioned for the future here, as it has already been able to win several orders for e-mobility products. The manufacturing programme of the group of companies with its headquarters in Plettenberg includes precision components for transmissions, engines, differentials, axles, cardan shafts as well as for drive and chassis. The LINAMAR SEISSENSCHMIDT Forging Group is part of the Canadian Linamar Group.

A large and important order came from a well-known customer for a transmission wheel. This is to go into series production at the end of this year. The gear wheel is forged on fully automatic Hatebur presses in Plettenberg and the mechanical processing also takes place at this location. One challenge besides forging on the Hatebur unit was the mechanical machining of the component. For the mechanical processing of the gear wheel, three different process steps on two processing machines as well as a needle embosser had to be linked in a sensible and at the same time economical way.

In order to solve this challenge or process as intelligently and efficiently as possible, cross-departmental cooperation was carried out under the theme of "collaborative robotics".

A COBOT PROVIDES RELIEF

In collaborative robotics, also called human-robot collaboration (HRC), man and machine work hand in hand at one workplace. Collaborative robotics does not require fencing because the technology of this robot is much more sensitive than that of conventional robots. Due to the more intelligent control technology, the robot can work much more closely with humans. Each collaborative robot, also known as a cobot, must also be approved by the TÜV and approved for collaborative work. In addition, the selected gripper of the cobot can also be approved by TÜV for the use of collaborative robotics. This is to ensure that the safety of the employees is guaranteed at all times. It is important to note that the robot is not intended to replace humans, but to support them in their activities.

For the gear wheel job, such a cobot from the Danish robot manufacturer Universal Robots has now been placed between two processing machines to assist the machine operator. The robot takes over the transport of the component between the first and the second processing machine as well as to the needle embossing. The machine operator can now devote himself more intensively to the actual quality of the machining of the raw parts and its inspection. At the same time, the productivity of the processing machine is increased by the use of a collaborative robot and the resulting shortening of the intermediate steps in the machining process. The focus of this partial automation is to relieve the machine operator of time-consuming and monotonous intermediate steps.

TEST TRIALS UNDER LABORATORY CONDITIONS WITH ZIMMER GRIPPERS

Before LINAMAR SEISSENSCHMIDT Forging decided to use the ZIMMER Group gripper, various types of grippers were tested internally under laboratory conditions. One challenge was to find a gripper that had the required gripping force to move forged components and at the same time ensure the safety of the employees. Even though the intelligent robot technology is TÜV-certified and thus has official permission to operate unfenced in production, the LSF team played it safe in the pilot project. This means that the cobot used there was additionally safeguarded with a laser, even though this is not a regulation. Similar to the interaction form of coexistence, the laser detects movements in the robot's occupied area. If something is in this area, the movement of the cobot slows down.

In addition to the safety of the gripper, the maximum gripping force, which meets the requirements of the component from the pilot project, was also decisive for the selection. According to ISO TS 15066, each HRC gripper has an approved maximum gripping force, which must not be exceeded for safety reasons. ZIMMER Group currently has the largest certified HRC gripper portfolio worldwide. However, due to the additional protection provided by the laser scanner, it was possible to use a conventional gripper with a higher relevant gripping force (based on the ISO TS 15066 guideline) for the component. The final decision was made in favour of the GEP5006IL model - an electronic, so-called 2-jaw parallel gripper from the gripper specialist ZIMMER Group. This has a high gripping force and at the same time a mechanical self-locking mechanism in the event of a power failure, which speaks for the safety and performance of the gripper. In addition, the control via human-machine interface (HMI) is already integrated into the user interface of ZIMMER GROUP components used on robots from Universal Robots  - a feature that can in principle also be implemented on robots from other manufacturers.


PROGRAMMING FOR EVERYONE

There are also different control techniques within collaborative robotics. In LSF's pilot project, the focus was on being able to use the cobot efficiently and flexibly in production. Therefore, the robot's ease of operation was also taken into account in the selection process. The ease of operation is convincing, especially in interaction with the gripper. Where previously time-consuming programming work and complex programming knowledge were required, the Cobot from Universal Robots and its gripper are very easy to operate. It is controlled or programmed directly via the robot operating panel, which is intuitively designed - comparable to a smartphone app. The pilot use of the cobot in the mechanical processing of LSF opens up new possibilities in terms of efficiency and flexibility. Thanks to the easy operability and installation of the intelligent robot and its gripper, the automotive supplier can now meet the increasing individualisation to a greater extent. This is of great advantage to LSF, especially for future plans to use human-machine collaboration.

FUTURE USE OF COBOTS AND ZIMMER GRIPPERS AT LSF

If the LSF pilot project proves successful in practice, the automotive supplier can imagine expanding this technology in-house. However, it is particularly important to the company that the employees benefit from the collaborative work. The cobots with their grippers are supposed to be a relief for the respective machine operator.

TO THE PRODUCT

UR-Roboter mit GEP5000IL-IO-Link-Greifer