ROEMHELD, a leader in clamping technology, has engineered a high-precision clamping and centering system tailored for grinding intricate printing machine components. Developed as an application-specific solution, this system utilizes HILMA machine vices from the new MC-P series. Implemented at the Brandenburg plant of Heidelberger Druckmaschinen AG (Heidelberg), it enables the machining of surfaces on delicate workpieces with minimal deformation.

Heidelberg has achieved exceptional precision, surpassing tolerance specifications to produce a flatness of less than 10 μm. The resulting flatness deviation falls comfortably within tolerance requirements, significantly outperforming values achieved with clamping devices from other manufacturers.

Precision Grinding of Unstable Components

In the realm of fine grinding, a challenging task arises when clamping a slender component. Measuring 500 mm in length, with a depth of merely 12 mm and a width of 90 mm, the workpiece exhibits extreme instability. Crafted from an iron-nickel alloy, the workpiece undergoes milling, drilling, and pre-grinding before reaching the grinding stage. Several years ago, the Brandenburg production site assumed responsibility for production, aiming to enhance its expertise and ensure consistent workpiece quality. "We are constantly embracing new production challenges," asserts Daniel Böttger from Heidelberg's Tool and Machine Technology Department, "and are dedicated to achieving perfection in our results."

Specific Search for Deformation Challenges

The Bradenburg company looked for support from clamping technology manufacturers but found that there were little to no useful solutions for the process. So, the company developed its own clamping fixture, achieving improved results. However, the rate of rejection continued at an unacceptable rate.

“The component lay flat, was clamped, ground, and then released—and was warped,” Böttger explains. In order to reduce scrap, half of the workpieces had to be reworked.

"We have a very large assortment, the total range of the ROEMHELD Group comprises more than 20,000 articles. If nobody else has a solution, we'll find it," says Neuhaus. "Even if we don't make any progress with standard clamping devices, we can help, because one of our core competencies is the development of systems for individual applications.”

Concentric and Position-Flexible Design of the MC-P Machine Vise

Drawing upon the versatile HILMA MC-P machine vice, which offers options for both position-flexible and concentric clamping, ROEMHELD engineers devised a tailored clamping solution through extensive testing. "Our goal was to get the most out of this element, which was originally developed for machining centers," reports the product manager.

In the concentric clamping configuration, two interlinked clamping slides move jointly towards the center of the clamping system. With the clamping spindle positioned high within the housing, any deformation of the workpiece is minimized.

For the position-flexible machine vices, the clamping point is floating when the locking is released. Similarly, the clamping slides initially approach the workpiece concentrically. Once the first clamping jaw makes contact with the component, the second clamping jaw adjusts until both are accurately positioned. The desired clamping force is then applied using a torque wrench, and the clamping point is secured via a clamping spindle, ensuring precise adaptation to the workpiece's position.

Development of an Effective Clamping system in a Short Timeframe

Following unsuccessful attempts with a combination of three concentric clamping vices with 100 mm jaw width, clamping technology specialists embarked on testing a more intricate solution comprising five elements. This involved a central concentric vice initially clamping the workpiece, followed by clamping on the right and left sides with two position-flexible vices, culminating in a locking mechanism. To enhance clamping precision, specially manufactured extra-flat clamping jaws, each 60 mm wide, were utilized for this application.

"Our internal tests worked very well," says Neuhaus, "so we were able to make the clamping system available to the customer at the beginning of June 2017 for free testing under production conditions.”

The system was well-received and eventually ordered by the company in November. This underscores the successful collaboration between design and technical sales, benefiting all parties involved.

Currently, the clamping technology experts are refining their comprehensive solution. Newly developed clamping jaws featuring a special coating for improved grip aim to further enhance machining outcomes.

About Heidelberger Druckmaschinen AG:

Heidelberger Druckmaschinen AG has been a reliable partner for the global printing industry for many years with a high level of innovative strength. For more than 160 years it has stood for quality and sustainability. This makes it a company with a long tradition, but at the same time Heidelberger Druckmaschinen AG determines the future trends in its industry thanks to modern technologies and innovative business ideas.

About ROEMHELD:

Whether for aircraft, automobiles, machine tools or cases for smartphones: technologies and products of the ROEMHELD Group have been used to manufacture numerous industrial commodities and goods for end users for more than 60 years.

Efficient clamping technology solutions for workpieces, as well as for dies in forming technology and plastics processing, form the core of our ever-increasing portfolio. This is supplemented with components and systems for assembly and handling technology, drive technology and locking mechanisms for rotors on wind energy systems.

As well as a wide range of approximately 20,000 catalogue items, the ROEMHELD Group is also specialized in the development and realization of customized solutions and is internationally respected as one of the market leaders for quality today.