GB1173534A - Improvements in or relating to Hydraulic Feed Arrangements for Honing Machines. - Google Patents

Abstract

1,173,534. Honing. P. NAGEL. 4 March, 1967, No. 10359/67. Heading B3D. A feed arrangement for honing - machines comprises a pressure rod for expanding a honing tool, the pressure rod being connected to an hydraulic piston drive which has a pressure control monitor responsive to pressure in a pump conduit leading to a thrust space of the hydraulic piston drive controlling an electric control means, said pressure control monitor being able to interrupt the pump delivery into the piston drive thrust space by switching over an electromagnetically-operated control valve by closing the electric control switch after rapid expansion of the honing tool has ended in the contact of the honing stones against the wall of a workpiece bore, said switching simultaneously controlling a piston dosaging device which may be controlled by time responsive means, the piston dosaging device being adapted to displace intermittently into the thrust space of the piston drive small partial quantities of fluid from the conduit upstream of the dosaging device to thereby activate the piston drive. A pump 1 delivers, at a pressure determined by a valve 14, to an electromagneticallyoperated valve 6 connected by conduits 7, 8 to the feed and return chambers 9, 10 of a feed cylinder 11 having a piston 13 connected to a presser rod 12 which expands the honing tool. The conduit 7 is connected to a pressure monitor 17 operating a switch 18. A dosaging device in the conduit 7 comprises a piston 16 in a cylinder 15 having an inlet port 20 and a non-return valve 21; upstream of the dosaging device the conduit 7 contains a storage loop 22. A pump 2 delivers, at a pressure determined by a valve 26, to a valve 28 electromagneticallyoperated under the control of a timer 34. The valve is connected by a conduit 29 to a cylinder 31 containing a piston 32 actuating the dosaging piston 16 against a return spring 33. For rotary adjustment of the dosaging piston 16 which has a chamfer 23, the piston slides in a pinion 36 meshing with a rack 35 movable by an electromagnet 37 against a return spring 38, the initial position of the rack being determined by an adjustable stop screw 39. Operation.-Electromagnet 37 is energized, rotating the piston 16 so that chamfer 23 registers with port 20. Valve 6 is in its righthand position, pump 1 thus supplying fluid to feed chamber 9; valve 28 is in its right-hand position, pump 2 thus supplying fluid to cylinder 31 to raise piston 16 until it holds open non-return valve 21. Rapid expansion of the honing tool is effected. After the honing stones -contact the wall of the bore; pressure monitor 17 operates switch 18 which (a) moves valve 6 to its mid-position, stopping pump delivery to the feed space 9 (b) de-energizing electromagnet 37 so that piston 16 rotates to a position determined by stop 39; and (c) starts timer 34 which periodically reverses valve 28 ;to reciprocate piston 16 whereby fluid is forced intermittently into feed chamber 9 to expand the honing tool intermittently.