Precision Manufacturing of Laser Drilling
The demands on technical products are becoming increasingly specialized, leading to a growing importance of small-batch production. For example, stricter emission regulations compel engine manufacturers to use injection systems tailored specifically to their setups. Standardized models from large-scale manufacturers no longer suffice, while in-house production often fails to justify the utilization of necessary machinery. GFH GmbH has therefore specialized in precision production for small to medium-sized series. Their systems are designed for flexibility, allowing reconfiguration for various applications even in low-quantity production. Despite this adaptability, GFH machines ensure process reliability and maintain tight tolerances, achieving micrometer-level precision akin to large-scale production standards.
View into the production area: GFH recently invested two million euros in new machinery and equipment technology.
A good prototype is no guarantee of the highest quality in series production," says Anton Pauli, managing partner of GFH. Until now, industries with high demands for precise processing often relied on large-scale production, where one million or more units of a model were produced. Specific requirements could not be taken into account in this process. "Our strength lies primarily in process-secure manufacturing in particularly low tolerance ranges for small to medium-sized series of about 100 to 100,000 units," says Pauli. The company specializes in precision manufacturing of various components and devices, such as injection components, medical instruments, or sensors for measurement systems.
With its experience in processes ranging from turning and milling applications to grinding, EDM, laser processing, and finishing, GFH is able to handle the complete manufacturing chain for injection components, for example, without relying on subcontractors. This allows the individual manufacturing steps to be coordinated and the production times to be gradually improved with a focus on quality. To support this, the company has recently invested two million euros in new machinery and equipment technology. For processes and requirements where no adequate processing systems currently exist, new in-house systems are continually being developed. This significantly contributes to the continuous improvement of manufacturing in terms of both quality levels and costs.
High-precision micro drilling in injection components
One of GFH's core competencies is the production of micro-holes, and the company is a global technology leader in this area. The manufacturing is done through machining, EDM processes, or laser drilling technology. In addition to cylindrical holes, positive and negative conical holes with a K-factor up to 20 are also possible (K1 corresponds to 6 d = 10 µm/mm). This particular expertise of GFH is especially used for injection holes: Since the injection hole drilling has a decisive influence on internal combustion, the focus is on precisely manufacturing the hole geometries within pre-set tolerances. In this process, the company not only creates the hole itself but also takes care of the exact calibration of the injection hole through hydroerosive processing with the help of a fluid abrasive. This method achieves an accuracy of < ± 1 percent of the total flow rate. To ensure the quality of their laser drilling, GFH has developed a non-destructive method using a negative imprint procedure, through which the size and geometry of the injection hole can be verified. Traditional measurement methods required cutting the components, meaning that measurements could only be done on a sample basis. However, with the new method, a special two-component material, custom-made by GFH for this measurement process, is injected into the nozzles. This creates a negative imprint, from which the measurements can be taken.
In the manufacturing of injection components such as nozzles, laser drilling in the micrometer range is required. For precision manufacturing, GFH has developed its own measurement procedure that delivers highly precise results.
Various measurement and testing systems for the highest possible manufacturing quality.
GFH's range of services also includes surface finishing, from simple laser engraving to 3D micro-structuring. Depending on the requirements, topographies can be created to minimize friction and material wear or to deliberately induce stick-slip effects. In many application areas, such as sealing surfaces, not only flatness and roughness requirements, but also the machining structure determine the functionality. Therefore, the precise measurement of surface quality is a crucial step in the production process. For this, GFH uses white light interferometry, a technique that non-contactly measures surface topography based on the interference of polychromatic light. This is one of several methods the company employs to ensure quality and precision. Others include the aforementioned negative imprint process, as well as additional coordinate, form, and position measuring systems. The data from these systems is processed statistically to monitor the manufacturing process. To coordinate production, GFH uses a custom-developed production planning tool, which allows for quick responses to short-term changes in drawings or specifications, ensuring short lead times.
"Our strength lies primarily in process-secure manufacturing in particularly low tolerance ranges for small to medium-sized series," says Anton Pauli, managing partner of GFH (Factory images: GFH GmbH, Deggendorf).