Specialty equipment manufacturer HAHN's automated, compact manufacturing cell assembles shock absorbers at 20-second intervals. Its automation solution includes a range of safety sensors, such as a safety gate system and coded safety switches. These sensors are connected via peripheral devices to Pilz's configurable, compact control system, PNOZmulti 2, to ensure safe operation and maintenance of the automated assembly system.
Support from PNOZmulti Configurator, a configuration tool for small controllers: HAHN benefits from highly efficient device control, saving time and costs. For HAHN, Pilz has been a trusted one-stop supplier of components, systems, and competent advisors for 20 years.
High-efficiency assembly
Within a 5m by 2m assembly unit, two rotary tables are used for final assembly testing in the factory workshop. At the loading station, a worker inserts the central tube into a pneumatic trolley and inserts two sewn support rings into nests at the adjacent station. He leaves the safety zone of two pairs of light curtains and initiates the assembly process via an operating switch: the grippers on the rotary index table close; the alignment cylinders retract automatically. The rotary index table is now clear and can cycle. The following describes the multi-stage assembly and connection process via two rotary table modules (eight in total). First, the provided O-rings must be placed in the appropriate grooves: the insertion funnel itself is positioned above the central tube, the grippers pick up the support rings, and a three-part assembly tool pushes the support rings into the desired position. Then, a processing unit connects the central tube to the inner tube, and the grippers apply the assembly removal. The trolley is back in its starting position, ready to receive the next part. The transfer unit transports the semi-finished shock absorber components to the first station on the adjacent rotary table. The position and positioning of the shock absorber components must be maintained. The insertion unit pushes the pressure adapter down until it is positioned at the required height. In the penultimate station of the rotary table, pre-installed shock absorber units are pressed onto the valve cone; sensor technology is used to reliably monitor force and displacement. If subsequent testing indicates that the shock absorber meets quality specifications, the approved components will be removed from the final station.
Keywords: flexibility
The assembly unit will soon be delivered to the production facility of a well-known automotive parts supplier, which operates on a three-shift system. The unit will produce shock absorbers continuously at 20-second intervals. The equipment is highly flexible, requiring minimal changeover and downtime, and can manufacture up to eight different types of shock absorbers with inner tube lengths ranging from 200 to 600 mm. The rotary table-based automation solution saves space, allows for shorter changeover times, and is ideal for complex component assembly. Specialty equipment manufacturer HAHN Automation is located in the Rhein-Hunsrück region. The rotary table is just one of several methods for translating customer needs into technologically advanced solutions. HAHN Automation, an international company within the HAHN Group, employs approximately 800 people in 12 countries worldwide and has been dedicated to developing efficient solutions, particularly for automating assembly and testing processes, for the past 25 years. Its target industries include automotive, consumer goods, electronics, and medical technology. “Our customers appreciate our extensive expertise and above-average development and vertical integration capabilities,” says Dirk Scherer, head of the electrical design team.
Focus on security
For HAHN, safety has always been a top priority. The requirements for safety are considered equally important as the effectiveness, efficiency, and operability of equipment. Their core mission is to protect personnel near equipment from danger, but these safety principles do not hinder operation or production processes, nor do they provide any justification for manipulation.
HAHN Automation quickly realized that flexible software solutions were superior to hardware applications, which were more prone to problems throughout the process, from engineering and commissioning to production, and were also more complex to install. In 2002, the PNOZmulti controller was launched, offering four modules: for the first time, users could generate software programs from a single computer to control multiple safety-related functions on a single device. Configurable inputs and outputs provided electrical design engineers with unprecedented flexibility. Soon after, HAHN Automation began using the configurable, compact PNOZmulti controller, with Pilz having been HAHN's safety partner from the beginning. "Pilz has extensive expertise in safety applications," said Dirk Scherer, "and their product portfolio is perfectly suited to our equipment."
Modular model solutions are the goal
Pilz's safety solutions will undoubtedly be applied to the current assembly unit. Specifically, HAHN's automated development equipment comprises two modules, built separately, which are then interconnected to form a combined unit. The two modules share a single controller, managed through an electrical control cabinet. In addition to cylinders, servo drives are used for material handling. Risk analysis indicates the need for appropriate safeguards for two interfering areas and five doors that only need to be opened during maintenance.
The required security solution is not just a customized solution for this device, but a flexible, modular, and scalable solution model applicable to similar devices.
The configurable compact controller PNOZmulti2 provides a clear case study: its modular hardware platform and extensive expansion modules easily cover a wide range of functions, from emergency stop monitoring, safety gates, safety light curtains, two-hand controls, pressure safety valves, analog measurements to motion monitoring. Depending on the application, the PNOZmulti 2 can meet or exceed EN ISO 13849-1 PL e/Cat. 4 or EN/IEC 62061 SIL CL 3 standards. The base unit, PNOZ m B0, provides 20 safety inputs, including 8 freely configurable auxiliary outputs, 4 safety semiconductor outputs, and 4 configurable test pulse outputs. Up to 6 expansion modules (I/O or motion monitoring modules) can be connected when needed, enabling numerous safety and automation functions with just one base unit.
Complete automation solutions
By combining Pilz's PSENcode contactless coded safety switch for position monitoring, a single pair of safety light curtains can ensure the safety of two interfering areas. Pilz's contactless safety door system protects five safety doors instead of traditional mechanical safety switches. PSENslock integrates safety monitoring and contactless magnetic locking functions into a single unit. This product, combining safety position monitoring and process protection, is highly versatile and meets stringent safety requirements.
HAHN Automation currently favors a distributed, intelligent installation approach, and Pilz's PDP67 module is particularly well-suited for signal collection. Distributed modules reduce installation and wiring workload, saving time and costs, and further reducing space requirements within the control cabinet. It boasts an IP67 protection rating, making it dustproof and waterproof. At first glance, it may seem complex, but with the PNOZmulti Configurator configuration tool, everything becomes much simpler: using a graphical user interface, the entire safety concept can be intuitively implemented on a computer. The configuration tool provides support from project design, configuration, documentation, and debugging all the way to production on the client side.
“We have a long-standing, equal partnership with Pilz, which provides reliable support on safety-related issues. While our own electrical engineers are highly trained, the aspects covered by the standard DIN EN 13849 are very complex. With Pilz as a strong partner, all questions regarding technology, products, and efficient solutions are readily answered, resulting in solutions tailored to our customers,” Dirk Scherer concluded.
