The JUCENTER CBN high-speed grinding machine combines mutually complementary grinding possibilities under one hood. Instead of lining up individual grinding machines for different grind-ing tasks, both grinding processes take place in two separate clamping set-ups on one machine. The result: highly efficient grinding – all with top precision.
Gear shaft grinding At station 1, JUCENTER grinds plunge-cuts and faces in a high-speed gear shaft grinding process. With the help of a B-axis, the grinding spindle can be swiveled to grind plunge-cuts, as well as faces with very fast cycle times. In station 2, multiple-bearing grind-ing of all centric diameters takes places
In station 1, CBN multiple-bearing grinding of all centric diameters (bearings and pivot) takes places. Parallel to this, other grinding carriages in the next clamping set-up (station 2) carry out non-circular grinding - that is, the grinding of main bearings. This is done using the pendulum grinding method with separately controlled CBN grinding wheels. Depending on workpiece-specific factors, workpieces can also be run in the opposite direction (from station 2 to station 1).
In station 1, sets of bearings are ground with one plunge-cut, using multiple-bearing technology. In station 2, JUNKER offers a versatile solution for grinding a variety of cam shapes. By using two independant infeed axes on station 2 for non-circular grinding, the machine can grind cams with unequal radial alignment just as fast as when using a set of grinding wheels.
The Erwin Junker Operator Panel was specifically developed to control grinding machines. All machine components are controlled using the operator panel – irrespective of the series and the used control system. The identical structure, intuitive menu guidance and visualization of the workpiece geometry make for extreme user convenience and flexibility in operation. Programming takes place directly using the operator panel or an external programming tool.
An integrated loading gantry reduces downtimes to an absolute minimum: it picks the blank up from the conveyor, brings it to station 1 and removes the ground part, which is then brought to station 2. The transfer options for blanks and finished parts outside the machine can be defined by the customer.
The machine bed made of mineral cast provides impressive damping behavior and torsional rigidity. The temperature stability allows fluctuations in the ambient temperature to be compensated with a minimum of effort, ensuring a high level of dimensional stability throughout the whole day.
Depending on the application, the abrasive CBN or diamond is used. The basic bodies of the grinding wheels comprise steel or carbon. In conjunction with CBN, it can make sense to use a carbon base body: It is light, has vibration-damping properties and remains dimensionally stable even at high speeds.
The measurement systems are also individually adjusted to the various workpieces and customer specifications. The measurement processes entail evaluating the recorded measured values and utilizing them for measurement correction in line with the prepared measurement strategy. A grinding wheel measuring system to determine the diameter, axial position and width of the grinding wheel completes the wide range of systems on offer.
JUNKER offers both internal and external loading systems for all its machine series, depending on customer and workpiece requirements. The loading systems can be combined with different infeed and discharge systems such as conveyor belts or custom tailored systems.
Grinding wheel dressing is CNC controlled. A driven diamond dressing wheel or a workpiece-dependent diamond profile roller can be used. Dressing takes place manually or using an automatic dressing program with grinding wheel compensation.
In order to generate a precise width and angular position of the main and pin bearing, the position must be precisely determined when clamping the crankshaft. For this, a touch probe measures the radial position of the pin bearing and the longitudinal position of the main and pin bearing. The measured values are automatically integrated in the grinding process by the control system.
In case of an fire, the machine interior is automatically hermetically sealed, suffocating a fire before it has a chance to spread. If required, extinguishers (CO² or water mist systems) and exhaust air purification systems can be additionally installed. A competent partner for fire protection and filtration solution solutions is LTA Lufttechnik GmbH, which also belongs to the JUNKER Group and which researches, develops and produces filtration systems for industrial air purification.
The Filtration systems
All JUCENTER versions can also be equipped with carbon grinding wheels. Technical advantages are higher cushioning and reduced weight. There is also an important economic aspect: higher productivity thanks to longer tool life and dressing cycles, as well as significantly fewer wheel changes.
As an option, self-centering three-point steadies ensure stable support. Tracking hydraulic jaws guarantee a balanced ratio of forces at all three support points, and with it a grinding process with repeat accuracy.