Double-disc surface grinding re-defined

During production, any expensive extra that wasn’t necessary for achieving the stipulated goal was foregone. Instead, it was precision that was of paramount importance: Great importance was therefore attached to a high degree of rigidity provided by a closed box frames instead of a C-frame, forged instead of turned tool spindles, 360° spindle tilting mechanisms and a double-walled frame design for temperature insensitivity. Indeed, the all-important dressing process requires such rigidity in order to create the appropriate tool geometries.

Other highlights include the spindle sleeve feed system in conjunction with a worm gear, the associated patented pneumatic compensation for thread play and high-precision ABEC-7 class bearings. Furthermore, effective options are also included such as an automatic tool-wear compensation system for the lower grinding disc provided by in-process measurement and a post process measurement with MARPOSS working in a closed loop.

This leads to exceptional machining results: With steel piston rings with a diameter of 68 mm, parallelism below 6 µm, and surface results of Ra 4.0 µm can be achieved with a cycle time of 1.3 seconds. In another application using aluminium, the machine achieves a removal of up to 0.5 mm per pass in 1.0 seconds with a parallelism of 10 µm.

User friendliness and minimal changeover times are other important advantages: A patented swivel transport disc bracket allows the operator to change the grinding discs easily through the large front opening just a few seconds after the spindles have come to a stop. This can be done in just a few minutes using an adaptable tool-changing aid. The pneumatic panel and the control cabinet are also easily accessible. Depending on the tolerances to be achieved, workpieces can be machined using a flow, flow/plunge or oscillation process. For the highest component specifications, the workpieces can also be propelled in the grinding gap with the appropriate transport disc designs.

Nissei has managed to compress this vertical machining solution into a footprint of just 2 x 2.5 m including the control cabinet, which also makes it suitable for compact production lines. There are various automatic loading options for feeding and removing workpieces, ranging from stack magazines to robots.

Whilst Nissei is responsible for the construction, installation and running-in of the client’s workpieces, all service aspects, including dealing with enquiries, advice, quotations and sample processing, through to commissioning, training, warranties and after-sales, are provided by the Thielenhaus team for Europe and North America. The project planning of automatic loading systems and filter systems is also managed by Thielenhaus so that a complete turn key solution can be offered. As a result, operators have the advantage of a local contact who can be reached quickly throughout the whole life cycle via the 24/7 service hotline. With this support, even small and medium-sized companies are able to purchase and operate a high-quality Japanese machine with a long service life and outstanding cost-effectiveness.