GB1347387A - Grinding method and apparatus - Google Patents

Abstract

1347387 Grinding BENDIX CORP 25 May 1971 [25 May 1970] 17030/71 Heading B3D A machine for grinding a workpiece 18 comprises means for advancing into each other an abrading member 12 and the workpiece, means for causing adjacent surfaces to be in relative motion to create a grinding action, and means for relatively moving cyclically the workpiece and abrading member transversely to the grinding and feeding motion. The workpiece is clamped against a shoulder 20 of an arbor 22 by a nut 24 and washer 26, one end of the arbor having a tapered bore 48 for receiving a centre 34 of a tailstock 30. The arbor has a bore receiving a piston 36 which is formed with a slot 42 engaged by a screw 40 in the arbor and has an extension 38 receiving the centre 30 of a headstock spindle 28 which transmits drive to the arbor by a dog 44 and pin 46. A nut 62 on the extension is adjustable to determine the extent of axial movement of the arbor on the piston 36. A chamber 58 at the other end of the piston is connected by passages 66, 68 in the arbor and tailstock centre and a pipe 20 to a pumping chamber 72 which is connected to a coolant tank 84 and has a piston 82 connected to a further piston reciprocated at a frequency determined by adjustment of a valve 26 in an air supply line. The tailstock centre 34 is mounted in a piston 49 urged towards the arbor so as to act to reduce the volume of chamber 58 by pressure of air in a chamber 50 connected by a control valve 56 and regulator 54 to an air supply 52. As the piston 82 is reciprocated in chamber 72, the volume of chamber 58 is cyclically expanded and contracted to effect reciprocation of the arbor 22 and workpiece through a distance determined by nut 62 as the grinding wheel is rotated and advanced into the workpiece. The grinding wheel is cooled by coolant supplied from a nozzle 96, may be cleaned by a jet, and dressed by a crush roller, the reciprocation permitting the coolant to reach the work. In another embodiment, a workpiece 100, Fig. 2, is internally ground by a grinding wheel cooled from nozzles 112 and cleaned by a jet cleaner 116. The workpiece is held by a clamp 106 on a shaft 110 mounted in bearings 128 in a ring member 126 having a portion disposed between ports 136, 138 connected by lines 152, 154 and orifices 148, 150 to an hydraulic source 146, the orifices being calibrated so that equal pressure is supplied to the lines. The lines are also connected by bleed lines 162, 164 to a four-way valve 166 which is controlled by a timer 172 and connected by adjustable orifices 176, 178 to a sump. As the valve is operated by the timer, the lines 152, 154 are alternately connected to the bleed lines and orifices 176, 178 to alternately drop the pressure at the ports 136, 138 so that the ring member 126, and hence the shaft 110 and workpiece 100 are reciprocated. When the workpiece is to size, the pressure at the ports is equalized to centralize the wheel.