Clock crown press-fit

Clock crown press-fit

In watch manufacturing, one of the production processes consists of pressing the crown onto a pin. Our customer previously carried out this process using a pneumatic press. The pressing was carried out on a block. For quality assurance, random samples were then taken and checked by hand for tensile force. However, it sometimes happened that components with insufficient holding force were passed on to the subsequent production process. 

As part of a modernization with the aim of improving quality, our customer opted for a flexiPRESS electric servo press from Parkem. The servo press electric actuator, force sensor and the comPRESS force measurement control system were designed to meet the exact requirements. The same applies to the easyPRESS press function.

Due to the special requirements, an easyPRESS standard function has been expanded to include additional monitoring, which records and evaluates the force difference during the pressing process. This massively optimizes the hit rate between "good" and "bad" components. Even the smallest deviations are detected. The bad parts are sorted out immediately and do not move on to the next production step.

The EtherCAT real-time bus is used as the interface. In combination with the comPRESS force measurement controller, in which the drive controller is directly integrated, fast response times of just a few milliseconds are possible, even when transmitting several set and actual values (cyclical and acyclical). The force sensor is read out and evaluated in the internal 500us task.

How Parkem supported the customer

  • Design of the electrical and mechanical components
  • Integration of the selected functions and interfaces in the force measurement controller
  • Connection of force measurement control via EtherCAT to Beckhoff controller incl. bus mapping
  • On-site commissioning and support for various test measurements with different samples

How the customer has benefited

  • Optimum selection of components and functions (modular concept)
  • Cost-effective servo press well under CHF 10,000
  • Ethercat interface and data transmission tailored to the application, incl. bus mapping
  • Fast cycle times, high sampling rate of the force sensor
  • Support from Parkem from design to commissioning