Raycon Introduces Microhole Drilling Machine

Raycon, a TransTec company, launched the Novagen EDM 4 head drilling center. The latest in the Raycon family of microhole drilling machines, it is capable of precision drilling microholes in a wide variety of injectors. It offers up to 25% faster drilling than previous machines and is capable of machining holes of 0.1mm diameter up to 1mm deep.

      The design is an evolution of technology proven on other Raycon machines, and has been developed using expertise gathered from many years of experience working with fuel system designers throughout the world. It incorporates the Raycon patented flow measurement technology, which can be used for either closed loop control (hole to hole control) or adaptive control (i.e. trend adjustment). The flow system measures the total flow of each nozzle and generates an SPC analysis of the latest 32 parts. From these results a deviation of the average flow from the drawing mean requirement is generated. Using the software database within the generator, parameters are selected to bring the average flow and the drawing mean to the same figure. This means that the absolute size of the electrodes are not vital.

      The Novagen ensures reduced drilling time and less variation in hole size - for example, with a 0.2mm diameter hole and a flow accuracy of 5%, the hole diameter drilled is within 0.005mm, for a 0.1mm hole size and a flow accuracy of 1% the hole diameter is within 0.0005mm. The machine makes machining reverse taper possible and provides for simpler part changeover and simple machine calibration.

      This is achieved due to the design and advanced technology utilized on the Novagen. The innovative axis configuration provides the flexibility to accommodate the various types of injector for both diesel and gasoline engines.

      One to four components are mounted vertically onto locations on individually programmable A-axis stations. The A-axis assembly is in turn mounted on a servo driven U-axis. This simplifies tool and part changeover and gives accurate control of sac center position. The A & U-axis assembly is mounted on a programmable C-axis which allows accurate adjustment of the spray angle.

      Mounted opposite the part locations are the EDM servo heads which in turn are mounted on a linear X-axis which provides accurate electrode/noseguide stand-off position. The electrodes and EDM servo heads which are mounted horizontally are not adversely affected by gravity, thus allowing more compact noseguide design, leading to smaller diameter hole drilling.

      Access to the positioning module is only required from the front of the machine and to the control equipment from the rear. This means the machines can be sited close to each other which, when combined with the reduced footprint afforded by the new design, this makes Novagen economical in terms of floor space. During machine operation the work area is totally enclosed. This highly practical machine configuration is supported by similar improvements in the machine control system, process control and maintenance requirement.

      The nanopluse generator has increased the machine's out current, stable output, and high voltage even at maximum current. The use of high quality cables ensures maximum benefit from the higher switching frequency. Optimum parameters are selected automatically from the resident database to simplify part programming. The EDM generator has up to 10 EDM parameter blocks per program, and is capable of drilling up to 25% faster than previous machines - for instance a 1mm deep hole of 0.2mm diameter can be produced in about 25 seconds - and can drill holes of 0.1mm diameter up to 1mm deep. Parameter changes are controlled accurately with depth relative to the first spark zero datum on the part surface. A warning indicator can advise automatically that the electrode is below the usable level. The parameter changes during the drilling process ensures compliance with the requirement of fuel injection design that only a taper of less than 5 microns (0.005mm) can be accommodated within the depth of the hole.

      The Novagen is controlled by an Amchem developed, PC-based open architecture control system. The Windows-based operating system provides a friendly interface with drilling parameters being selected from the database. Based on Digital Signal Processing technology, it provides simple data input defining both machining parameters and position on a "page per hole" basis and has no requirement for standard part programs. A distributed I/O system using the latest Interbus technology reduces machine wiring, simplifying machine maintenance and improving reliability.

      For more information contact:
      Don Braden
      Raycon Corporation
      2850 South Industrial Highway
      Ann Arbor, MI 48104
      734-677-2614
      Fax 734-677-2778