Patent GB-956385-A (GB)
Title: Honing method and apparatus
IPC: B24B33/02
Filed: 1961-02-22
Abstract: 956,385. Honing. MICROMATIC HONE CORPORATION. Feb. 22, 1961 [Feb. 23, 1960], No. 6571/61. Heading B3D. The bore of a workpiece is honed by rotating a honing tool in the bore in a given direction, reciprocating the honing tool in the bore, intermittently introducing gauge means into the bore to sense the enlargement to a predetermined size, and reversing the direction of rotation of the honing tool in response to sensing of the enlargement of the bore to a predetermined size. A carriage 26 mounted on ways on the machine frame 22 is movable, by piston and cylinder device 260, towards and away from the workholding fixture 27. The carriage 26 has a housing 30 with a cylindrical bore 32 containing a quill 34 provided with piston rings 36 which receive the pressure of hydraulic fluid admitted to the bore 32 to effect reciprocation of the quill 34. A reversible motor 56 suspended from the underside of the carriage 26 drives, through belts 54 and gears 53, 51, a spline shaft 50 mounted in the carriage 26 and engaged by an internally splined sleeve 46 rotatably mounted in a housing 42 secured to the rear end of the quill 34. A gear 48 on the sleeve 46 drives a gear 40 on a spindle 38 rotatably mounted in the quill 34. The spindle 38 is connected by a pin 62 to a tubular coupling 60 to which a tubular drive member 74 is secured by a nut 76. The end of the drive member 74 carries flange members 150, 152 the bores of which receive a pilot portion 148 of the honing tool drive shaft 120 which is secured by a collar 154. A stone expansion rod 118 is secured by a pin 158 to an expansion member 130 having circumferentially arranged sets of cam surfaces 166, 168, 170 bearing against the seats of honing stones 126, 124, 128 so that the stones are expanded radially when the member 130 is moved axially. A piston 64, movable within the tubular coupling 60 by fluid pressure, is bolted to a rod 66 having an end portion disposed within a sleeve 68 and secured thereto for co-rotation by a pin 70 the ends of which engage helical slots 72 in the drive member 74. The sleeve 68 is internally splined to receive the splined end 78 of a push rod 80 having ball detents 162 engaging a grooved member 610 on the end of the push rod 118. A pin 84 extends through a transverse bore 82 in the rod 80 and through slots 86 in the drive member 74. The wall of the bore 82 is inclined to the axis of rotation. Thus axial movement of the piston 64 effects axial movement of the push rods 80, 118 rapidly expanding the honing stones. The ends of the pin 84 fit within an inner collar 88 surrounding the drive member 74 and rotatably mounted within an outer collar 92 externally threaded to engage internally threaded adjusting sleeve 94 on which is rotatably mounted a worm wheel 96 which can be locked to the sleeve 94 by manual operation of a pawl or clutch 98. The worm wheel 96 meshes with a worm 104 on a shaft 106 journalled in a housing 108 mounted on the forward end of the quill 34. The shaft 106 is driven, through worm wheel 110 and worm 112, by a reversible fluid motor 116. The outer collar 92 is held against rotation relative to the housing 108 so that actuation of the motor 116 to rotate the sleeve 94 effects axial movement of the outer collar 92, inner collar 88 and pin 84, causing axial movement of the push rods 80, 118 to expand the honing stones. The workholding fixture 27 supports a number of workpieces W, e.g. connecting rods while the bores in their big ends are honed. The fixture includes a bed 174 supported on a vertical shaft 176 rotatable by worm gearing 178, 180 so that the fixture can be indexed 180 degrees to position one batch of workpieces in register with the tool 122 and to bring the other batch out of register with the tool for loading and unloading. The bed has supporting blocks 182, 184 on either side of a supporting block 186. The big ends are supported on the blocks 182, 184 with the rod portions alternately extending in oppoite directions. The big ends are disposed in alignment and supported by parallel spaced vertical plates 196. Torque plates 198 above the big ends receive the force tending to rotate the workpieces when the honing tool is rotated in a given direction. Each of the plates 198 has a coupling 210 through which coolant is admitted for cooling the workpieces. The small ends rest on abutment members 200, 202, 204, 206, the outwardly disposed small ends of the batch being honed being positioned below a stationary torque plate 208. The inwardly disposed small ends of the batch being honed are restrained against upward movement by shouldered members 212 carried by a rod 214. To permit loading and unloading the members 212 are normally held out of vertical alignment with the small ends by springs 216; the rod 214 off the batch in honing position is abutted by a rod 218 on the carriage 26 when the latter is moved into honing position. A disc-shaped air gauge 220 is carried on a shaft 222 so as to be movable by an air cylinder 224 in and out of the bores of the workpieces at the right-hand end of the batch, the gauge coming to rest in the workpiece which is second from the end of the batch. The shaft 222 is supported by a bracket 226. The air cylinder 224 is mounted on a platform 232 of the frame 22. A rod 234 carried by the shaft 222 has a finger 236 arranged to actuate a limit switch LS3 when the gauge is within the bore. As the tool is reciprocated it contacts the gauze pushing it out of the bores at the end of its stroke against the bias of the cylinder 224, the contacts of switch LS3 being opened to prevent a false indication of bore size. The gauge has bevelled flange portions 220a, 220b facilitating its movement in and out of the workpieces. On its periphery the gauge has a pair of diametrically opposed nozzle orifices 228 from which air is emitted against the wall of the bore. The air is passed through a control unit 230 containing switches responsive to the back pressure, and set to trip at varying pressures to sense predetermined diameters. The hydraulic control circuit includes variable delivery pumps 252, 254 driven by an electric motor M and drawing fluid from a tank T through strainers S. A panel 256 controls reciprocation of the quill 34 and admission of pressure to the piston 64. A valve 258 controls the movement of the carriage 26 which operates forward and rearward limit switches LS1, LS4. Compressed air is supplied to the pneumatic circuit through a filter 278 and pressure regulator 280. A valve 270 actuated by a solenoid 3 controls the operation of the air cylinder 224. Operation.-Closure of start switch S2 energizes relay CR1 and SOL.1, the latter actuating valve 250 supplying fluid to cylinder 260 to advance carriage 26. When the carriage reaches the end of its stroke, switch LS1 is closed, (a) energizing SOL. 2 initiating reciprocation of quill 34 and (b) energizing SOL. 3 actuating valve 270 supplying air to cylinder 224 causing air gauge 220 to be advanced into the bores of the workpieces. Upon the first reciprocation of quill 34, pressure switch PS1 is closed (a) energizing forward motor starter relay F producing forward rotation of the spindle drive motor 56; (b) energizing SOL. 4, SOL. 5 actuating valves 272, 274 starting fluid motor 116 to effect expansion of the honing stones beyond that to which they were expanded by piston 64. When the gauge enters, limit switch LS3 is closed energizing relay TD1. After a delay, contacts TD1A close. When the bore diameter reaches a value slightly less than desired, pressure switch PS2 closes, energizing relay CR2 energizing reverse motor starter relay R and de-energizing forward motor relay R, whereby rotation of spindle motor 56 is reversed. Upon attainment of final desired size, pressure switch PS3 remains closed after the gauge has entered, energizing, through time delay contacts TD1B, the relay CR3 energizing relay TD2. After a time delay contacts TD2A close, energizing SOL. 6 causing complete retraction of quill 34 and retraction of piston 64. Opening of contacts TD2B de-energizes relay CR1, deenergizing SOL. 1; closing of contacts TD2A energizes SOL. 7; valve 258 is thus actuated to fully retract carriage 26. Energization of SOL. 8 actuates valve 274 to reverse the motor 116 and collapse the tool; after a time delay, contacts TD3A open to terminate the collapse.