The Development Trend of CNC Compound Surface and Back Grinding Machine

At CIMT2019, the world’s leading grinding machine manufacturers all participated in the exhibition. The following is a brief review of some representative CNC precision all-round cylindrical grinders, namely compound cylindrical grinders, in this exhibition.

1. Introduction of some representative exhibits

1. S31 CNC fine all-round cylindrical grinding machine from STUDER of UNITE GRINDING Group

The new S31 CNC universal cylindrical grinder is a new model launched in 2019. The center of the exhibition is 175mm high and the center distance is 650 mm. During the exhibition, the machine tool demonstrated the use of two cylindrical grinding wheels to grind the step shaft.

Compared with the old model, the main change of the new model is: the machine adopts a new appearance, the center distance is widened from 650/1000mm to 400/650/1000/1600mm, the maximum workpiece weight supported by the center is changed from 120 kg to 150 kg, and the X-axis travel is changed from 280 mm is increased to 370mm; the bed adopts a new design, the sink is directly cast from artificial stone, and the grinding wheel dresser is installed on the double T-slot of the worktable to reduce the workload of adjustment and replacement. The B axis cancels 2.5 degrees Indexing, direct drive and high-resolution measurement can be used with a grinding wheel to grind multi-diameter and multi-cone surfaces without dressing the grinding wheel; the CNC system is changed from FANUC31i-A to 0i-TF, and 31i-B becomes high-speed grinding Cut options.

This machine tool can be equipped with an all-round work head, which can perform both live spindle grinding and two-center grinding. It can also be equipped with a chuck type work head suitable for grinding with chuck clamping. The workpiece headstock spindle is equipped with roller bearings, which are almost maintenance-free and can reach extremely high-precision roundness 0.4μm during live spindle grinding. 0.2μm is optional. When the live spindle is grinding, the cylindricity can be adjusted within 1 micron through the fine adjustment equipment of the workpiece headstock. Same as the tailstock, the workpiece headstock is also equipped with air cushion lifting organization, which is convenient for the movement of the workpiece headstock during the adjustment of the machine tool setting.

The machine is equipped with a stretch spring tailstock as standard, which is clamped by the stretch spring tailstock sleeve, and the taper can be fine-tuned. Tailstock equipment 1: Morse No. 3 center, sleeve stroke 35mm, sleeve diameter 50 mm; Tailstock equipment 2: Morse No. 4 center, sleeve stroke 60mm, sleeve diameter 60mm. It can also be equipped with a synchronous tailstock with a load-bearing capacity of 50kg. When grinding the full length of the workpiece, or when the conventional workpiece drive mode cannot be used, the synchronous tailstock will be particularly economical and efficient.

STUDER also exhibited the new S33 CNC fine all-round cylindrical grinder. This series of grinders are basically universal with the new S31, with outstanding and cost-effective features. The main difference is the wheelhead equipment.

2. Hardinge Group’s new JONES&SHIPMAN 10 CNC fine all-round cylindrical grinder, etc.

Judging from the new JONES&SHIPMAN 10 CNC fine all-round cylindrical grinder, the new KELLENBERGER100 and 1000CNC CNC precision machining fine all-round cylindrical grinder, Hardinge Group has carried out a greater integration of its fine all-round cylindrical grinder products, which is also After acquiring JONES&SHIPMAN, it has integrated its grinding machine line products and launched a new product many times. This product has an outstanding cost performance.

The new KELLENBERGER 100 and 1000 CNC fine all-round cylindrical grinders are new models launched by Hardinge’s KELLENBERGER company’s integrated grinder products. Among them, KELLENBERGER 1000 represents its highest level of grinding. This series of fine all-round cylindrical grinders has a center distance of 1000/1600mm, a center height of 200/250/300mm, and two centers with a load-bearing capacity of 150/200/300kg. The use of static pressure technology for each guide rail to meet the highest precision grinding requirements is basically the original KEL-VARIA series.

This series of grinders use HEIDENHAIN GRINDpuls 640 or FANUC 31i CNC system. The X axis of the grinding wheel carriage, the Z axis of the table movement and the B axis of the grinding wheel rotation are all selected by closed hydrostatic guides, and the X/C axis interpolation can be completed. Non-circular grinding/thread grinding/coordinate grinding/groove grinding, X/Z axis interpolation can complete taper grinding/general grinding/dressing, X/Z/B axis interpolation can complete with B axis The general grinding and the forming of the follow-up function are general grinding. At the same time, the use of static pressure guide rail ensures the linearity of 0.0015mm on the length of 800mm and the linearity of 0.002mm on the length of 1200mm.

The headstock can be equipped with standard type, chuck type and direct drive type. The headstock bearing selects high-precision roller bearings. The roundness of the workpiece is 0.4μm. 0.2μm is optional. C-axis non-circular grinding is equipped with Heidenhain circle. Raster. The tailstock uses dense bearing support sleeves, which have the function of fine-tuning the taper.

The grinding wheel frame can be equipped with various specifications of grinding heads. The cylindrical grinding head uses multi-oil wedge dynamic pressure bearings. Water-cooled motors: general, diagonal, front and rear placement types and mass production types. The B axis is directly driven by a torque motor. It can be locked without deformation. The grinding wheel active measurement system measures and stores the size of the grinding wheel. After the B axis rotates, the system automatically updates the grinding wheel coordinates. The internal grinding head uses high frequency electric spindle.

2. The development trend of CNC universal cylindrical grinders, that is, composite surface and back cylindrical grinders

1. Diversified wheel head equipment, rich grinding function. The grinding wheel holder ranges from the original typical 1 straight grinding wheel, 1 inclined grinding wheel and 1 internal round grinding wheel to the current universal type, diagonal type, front and rear placement type and mass production type. It can also be used for high-speed grinding of CBN grinding wheels. Grinding, can complete the grinding of various surface, inner and round parts of shaft sleeve parts in one clamping, and can be ground in small and medium batches or even large batches.

2. The skills of the B axis of the wheel holder are getting better and better. The B-axis drive has started with manual 2.5-degree indexing of the squirrel wheel, active 1-degree indexing, and successive indexing of the worm and worm gear driven by the servo motor, to the direct drive of the torque motor, the direct detection of the circular grating, and the bearing from the rolling turntable bearing to the current selection of closed Type hydrostatic guide rail. It can be used to grind multi-diameter and multi-cone surfaces with one grinding wheel without dressing the grinding wheel or X/Z/B axis interpolation. It can complete B+ general grinding and follow-up function forming general grinding.

3. Use static pressure guide rail or exclusive technical guide rail. Fine CNC universal cylindrical grinding machine worktable and grinding wheel guide rails are widely used to select static pressure guide rails or exclusive technical guide rails to ensure grinding accuracy and vibration resistance