Surface measurement technology in a rough environment

Transcription

1 Surface measurement technology in a rough environment Process Control Quality Assurance Cost Reduction

2 The perfection of measurement technology Measurement of roundness and waviness to multi-wave standard 2

3 OptoSurf places particular emphasis on the intensive consulting it offers its customers. Prior to delivery and productive implementation we always conduct meaningful test measurements Dr. Rainer Brodmann developed the first commercial scattered light measurement device at Rodenstock, together with the Technical University of Berlin 1989 Successful applications at Daimler, VW and IBM 2004 OptoSurf GmbH founded in Ettlingen 2007 First implementations in the manufacturing of crankshafts, ball studs and femoral heads 2009 Winner of the Innovation Award of the State of Baden-Württemberg 2012 Introduction of the first automatic measuring machine for waviness during the Control trade fair 2006 Market introduction of the second generation of the OS 500 scattered light measurement systems OptoSurf develops, manufactures and markets inline surface measurement systems for real-time quality assurance of precision parts during production. The focus areas are the automotive industry and the engineering industry. Our core competence is scattered light technology, which is particularly characterized by robustness, accuracy and high measurement speed. The objectives of all manufacturers of precision components and the objectives of the suppliers to these manufacturers, are to optimise cost-intensive manufacturing processes and reduce tool costs, to produce 100% tested parts and to investigate the functional behaviour of surfaces. OptoSurf now makes this possible with the new technology of its inline surface measurement systems. We view ourselves as a niche supplier supplementing the traditional manufacturers of tactile and optical surface measurement devices. 3

4 Scattered light measurement technology RZ 1,0 µm RZ 1,5 µm Macrostructure Microstructure Measurement method Scattered light measurement technology is a relatively new process, in which the surface is illuminated with a measuring spot, and the light beams deflected through the microstructure are measured with a detector. The resulting scattering angle distribution curve is a measure for surface roughness. The calculated characteristic value, Aq, is the variance of the distribution and is described in the VDA 2009 guideline. Advantage The great advantages of scattered light measurement technology are the robustness for implementation in rough environments, the high measurement accuracy, as well as the measuring instrument capability even for finely machined surfaces. Measured variables In the macro range the sensor works in accordance with the familiar deflection principle. The local form deviation angle is measured, from which for the known x, the absolute form deviation y can be calculated. For the roundness or straightness measurement, the sensor is either guided over the surface, or the measurement object is moved with appropriate precision. On extremely smooth, e.g. polished surfaces, even form deviations < 0.02 µm can be measured. 4

5 Sensor-system Sensor OS Ø 70 mm Ø 50 mm 140 mm 55 mm 5 Sensor OS Ø 70 mm Ø 57 mm System controller (PC) Reference standard and calibration set 170 mm 69 mm 50 Mode of operation The scattered light sensor consists of the light source for illumination of the surface, precision optics that detect scattered light distribution in the angle range of 32 or 16 and the linear detector that measures the scattered light distribution in the form of an intensity distribution curve. Via a fast USB connection the digitalised measured values are transferred to a PC, which then takes over calculation of the roughness characteristic value Aq. Technical data OS /16 n Scattered light sensor with 32 or 16 optics n Measuring range 1.6 < Aq<95 n Available measuring spot size: 1.8 / 0.9 / 0.3 / 0.03 mm n Measuring distance 5 or 50 mm n USB interface n Trigger input V n Up to 2,000 measurements/s n Degree of protection IP 65 5

6 Automotive industry Crankshafts Balance shafts Gearshafts Roughness and roundness measurement on the control gear Examples of various application possibilities Real-time quality assurance during the process In recent years engine manufacturing tolerances and transmission manufacturing tolerances have become ever more narrowly defined. The reasons for this are the increasing requirements imposed on surface quality to achieve friction and to avoid noise. In this regard, the stylus instruments formerly used for quality assurance are increasingly approaching their limits.the systems in the production-related area often no longer achieve the required measurement instrument capability. In this area scattered light technology offers incredible advantages because it provides extremely stable measured variables on surfaces with roughness values < 1µm Rz and reacts with particular effectiveness to the bearing ratio of the functional surfaces. Applications n Toothed racks Roughness measurement on the finished sliding guide n Crankshafts Roughness measurement of the finished main bearings and pin bearings n Gearshafts Measuring roundness, roughness and waviness n Pump plungers 100% roundness measurement in the submicrometer range and detection of polishing errors 6

7 Engineering industry Forming tools Bearing rings Linear guides In-process surface measurement on rollers Examples of various application possibilities 100 % Roughness measurement and form measurement In the engineering sector there are four key application areas for scattered light technology: - The roller bearing industry - Grinding of precision rollers - Flat grinding of linear guides - Inline measurement of thin sheet metal surfaces. Detection and measurement of waviness is the main priority for almost all applications. In addition, the Aq roughness parameter provides information on tool wear and characterises the desired surface texture. The fast scattered light sensor enables 100% measurement of all parts, and if required also measurement of the entire functional surface, as well, through the use of 3D scan technology. Applications n Needle bearing rings Waviness and roughness measurement on the honed raceway. Cycle time max. 3 s n Linear guides Waviness measurements, roughness measurement on the entire raceway n Rollers Measuring roughness and waviness while machining n Sheet metals, strips Inline roughness measurement of rolled and ground sheet metal surfaces and strip surfaces 7

8 Medical technology Nitinol tubes Artificial hip joint Artificial knee joint Automatic femoral head measuring machine Examples of various application possibilities Measuring 100 % of the surface In the medical technology industry extremely high requirements are imposed on surfaces of implants, for example. Thus the prosthesis head of hip joints must not have any scratches or contamination whatsoever over the entire surface. Form deviation must not exceed 2µm. On all polished medical technology surfaces, tactile roughness and form measurement devices pose problems because they could damage the surface, and in each case only a minute section of the functional surface can be evaluated. Scattered light technology enables 100% surface measurement for all parts within a short time with the appropriate sensor movement. Applications n Femoral heads Complete roughness, form and defect measurement with a special measurement fixture n Nitinol tubes Roughness measurement during the centreless grinding process n Polished surfaces Roughness measurement of special hand-polished implants 8

9 Measuring systems OptoScan 100 linear measuring station OptoShaft 12 shaft measuring machine Crankshaft measuring module Complete solutions for manufacturing For some applications we can already offer finished solutions, such as n Module for automatic measurement of the finish quality of crankshaft bearings The system is integrated in the PLC controller of the line via a PROFIBUS interface. n Measuring machine OptoShaft 12 for roundness, roughness and waviness of gearshafts In this case the shafts are clamped between centres. The sensor automatically measures all bearings at 3 points. Data transfer in accordance with qs-stat. n OptoScan 100 measuring machine for level or slightly curved surfaces Scanning of surfaces (2D or 3D) in 1-second cycles. n OptoRack 07 toothed rack measuring machine Measuring of roughness and waviness on the longitudinal finished surface 9

10 Software Process monitoring Form and waviness measurement Automatic surface measuring station Settings for machine control 10 Software characteristics The OS 500 software controls the software, processes the measurement data, presents it graphically, and in addition, stores all data (parameter settings and measured data) in an SQL database. Limit values can be entered for process monitoring, which when exceeded switch a traffic light from yellow to red or trigger an external control signal. Presets of the parameters, such as measuring point density, measurement length and filter settings can be saved under a name. For implementation in machines, the software can be controlled externally, e.g. via a PROFIBUS interface. Software characteristics n Aq (roughness), I (reflection), M (macro-angle). n Calculation of roundness (LSC) n Calculation of FFT (up to the 500th order) n Wave filter in accordance with ISO n Straightness, waviness for linear guides n Dominant waviness in accordance with VDA 2007 n Morphological filter Aq* for defects n Automatic parts detection n Excel data transport n qs-stat interface n Profibus interface

11 Software module 3D Grinding faults Directly after truing Just before truing Waviness on chromium layer Defect on deep-drawn part Softwaremodul 3D The software module SW 3D permits control of 2 motors for the whole-area roughness and waviness measurement of cylindrical parts (z/j), level areas with circular movement (x/j) or level areas with rectangular scan (x/y). Presentation possibilities n 3D graphics (Aq, I, M, WDSc, PV-Form) n Presentation of the raw data n Presentation of the filtered data n High-pass, low-pass, band-pass ISO filter settings Presentation of the measurement data viewed from above or as a projection permits Cartesian coordinates or polar coordinates. 11

12 Optical surface measurement with scattered light Fast Robust High Precision OptoSurf GmbH Nobelstr Ettlingen (Germany) Tel.: / Fax: / info@optosurf.de Internet: