Technologies for automotive systems
Innovative strength, development and process competence are decisive factors for Handtmann when it comes to being able to work successfully with our customers.
Here at Handtmann, we depend on state-of-the-art plants and systems for reliable assembly.
Welding of Cr/Ni steel using a solid-state laser in the pulse method. Flashlamp-pumped 250 W pulse lasers.
Welding of aluminium components using a fibre laser in the CW method. 3 kW diode-pumped fibre lasers.
In-process weld pool monitoring by means of a position-resolving, high-speed camera through detection of the back-reflected laser beam. This allows the recording and analysis of laser-specific quality features such as focal position, welding position, energy density, welding feed, shield gas, weld pool geometry, holes and spatter.
In-process weld pool monitoring by means of wavelength-based photodiode sensors. This records the back reflection of the laser beam, temperature of the keyhole (melt) and intensity of the plasma beam. For quality assessment purposes, the actual signals and their characteristics are viewed in correlation with reference signals from good parts.
The electron beam welding method enables – through the universal beam formation under high vacuum – the virtually error-free welding of aluminium pressure die cast, which presents its own problems due to the effects of compressed, trapped gases.
The electron beam produced in the generator at approx. 30-50 % the speed of light is magnetically focused and aimed at the surface of the component to be welded. When it strikes the component, the conversion of kinetic energy into thermal energy causes the material to melt. This method requires an environment under high vacuum, which in turn requires suitable chamber and vacuum technology in addition to the beam technology.
The rivetting method enables incredibly strong, resilient metal connections without the disadvantage of thermally induced structural changes in the base material. The radial rivetting technique also allows higher-strength steels to be plastically reshaped with little effort in order to achieve positive rivetting. The special hypocycloid path of the rivetting die makes dot-shaped contact with the workpiece and thus an even outward kneading of the material to be reshaped. Typical applications are shaft/lever connections for the transmission of torque.
The bolting methods used at Handtmann are based on fully electronic systems with integrated torque/rotation angle monitoring. The spectrum covers hand-held systems with mechanical or electronic position control as well as automated positioning systems. Depending on the degree of automation and the quantities required, the bolts can be supplied individually and screwed into place by hand or fully automatically.
The monitoring and control software also allows a sensitive bolting routine to suit the case in question. Thread errors, coating errors, missing workpieces and material errors can be detected and analysed.
Joining of pipe nozzles, pins and caps under the influence of high axial force. Pneumatic, hydropneumatic and electrospindle drives are used in the power units. In this way, more complex joining processes can be reliably organised by means of staggered process sequences. An online process evaluation of the connection is done by means of a sensory force-displacement measurement. Effects on the expected connection quality, such as surface, friction factor, coating and dimensional excess can be sufficiently determined in this way.
When it comes to testing components that operate under high pressure to ensure they are not leaking any liquid, this can only be reliably done by means of helium testing. The process involves completely evacuating the test chamber. This requires highly sophisticated vacuum pump technology. The test chamber is then pressurised with helium. The helium atoms, which are smaller than those of normal air, can easily penetrate any leaks and are then collected and analysed using a mass spectrometer. The method is used on components such as high-pressure fuel rails.
Low-pressure systems, such as suction systems, are tested for leak tightness using the differential pressure method. This involves subjecting the device under test and a reference test room in the measuring device to the same pressure. Next, a special differential pressure cell measures any differences in pressure caused by a component leak. This method enables measurements down to 1 Pascal, or 1/100,000 bar.
Handtmann uses a wide range of systems for the optical inspection of markings, assembly states and surface checks.
Marking: Code readers are used to decode and analyse DataMatrix codes. The codes themselves can be applied by means of label printing, dot peening and laser labelling.
End-of-line testing: This checks the correct assembly state. A camera image is produced and analysed under optimal lighting conditions. The respective inspection task can be performed by means of edge/object detection and the associated measuring algorithms.
Surface testing: Inspection of machined cast surfaces for pores and cavities by means of 2D cameras that can be moved on NC axes. Evaluation according to the light/dark field method.
All process data of the assembly systems relevant for the process are saved in databases. A cyclical analysis of these data in accordance with statistical methods enables a high degree of production transparency. Live displays of actual conditions therefore permit short response times in the event of departures from trend or increased error rates.