Patent GB-1373471-A (GB)
Title: Grinding machine
IPC: B24B5/14
Filed: 1973-01-18
Abstract: 1373471 Grinding SEIKO SEIKI KK 18 Jan 1973 [19 Jan 1972 (4)] 2699/73 Heading B3D  A machine for grinding the surface of a workpiece W, Figs. 2 and 6, comprises a base 1, a wheel carrier table 3 which is slidable in a first direction in the base, a plurality of rotatable grinding wheel carriers 11, 12 carried by the table, a feed table 32 mounted on the base and supporting a workpiece carrier 38, the feed table being slidable in a second direction which is at an angle with respect to the first direction, and means for locating the workpiece carrier and each of the grinding wheel carriers in relative operative positions. As described, the machine is for internal grinding of the surfaces of a workpiece. The table 3 is guided for linear movement in the first direction by roller guides 4, Fig. 4, in a stand 2 on the base 1 and has a follower 6, Fig. 5, secured thereto and urged by a hydraulic cylinder 5 into engagement with a cam 7c rotated by a motor 7a to effect reciprocation of the table. A first swivel table 9 is adjustable about.a pivot 9a on the table 3 and has roller guides 10 for a second wheel carrier table 8 which has a follower 17 urged by a hydraulic cylinder 16, Fig. 4, against a cam 19 rotated by a hydraulic motor 18 to effect reciprocation of the table 8. A second swivel table 13 is adjustable about a pivot 13<SP>1</SP> on the table 8. A grinding wheel spindle carrier 11 having a wheel 11<SP>1</SP> for grinding the bore a of the workpiece is mounted on table 13 which has a stand 13b slidably adjustable by a screw 14 and carrying a grinding wheel spindle carrier 12 having a wheel 12<SP>1</SP> for grinding a seal surface b on the workpiece. The first wheel carrier table has a groove 22, Fig. 1, for a pair of adjustable dogs 23, 24 which co-operate with a stop 25 having abutments 25a, 25b and with an intermediate stop 27 connected by leaf springs 27a to a rod of a cylinder 26 whereby it can be moved between operative and inoperative positions. A clamp 29 can be raised by a cylinder 28 to hold the dog 23 against the intermediate stop 27 for determining the position of the spindle 12 relative to the workpiece, and a similar clamp 31 can be raised by a cylinder 30 to hold the dog 24 against the abutment 25b to determine the position of the spindle 12 for dressing. The feed table 32 is mounted for movement at right angles to the movement of table 3 on a table 33 and is urged by a spring 35, Fig. 7, to a position determined by a screw 34. A shift table 36 is slidable on roller guides on the feed table by a hydraulic cylinder 37 to positions determined by abutment of screws 41, 42 with an abutment 43. A workpiece carrier spindle 38, Fig. 8, and its motor 39 are mounted on table 36, and the screws 41, 42 engage the abutment 43 to position the table 36 so that the workpiece spindle is aligned with either the grinding wheel spindle 11 or the grinding wheel spindle 12. The table 36 also carries a dressing device comprising an arm 46, Fig. 8, which is rockable about a pivot 45 by a hydraulic cylinder 47 to a position determined by a stop 51 so that dressing diamonds 49, 50 are moved into operative position. The table 32 is fed forwardly for a grinding operation by rotation of a cam 59, Figs. 3 and 7, which is driven by a motor 55 and engages a follower 70 in one end of a lever 68, the other end of which is pivoted to the stand 33 and has a part 68a abutting a feed rod 67 which, in turn, engages an eccentric disc 64 on a shaft 61 mounted in a housing 60 in the table 32. A control pin 71 is urged by parallel springs 74 against the eccentric disc and connected to sensors 76, (77, 78, Fig. 10, not shown), such as differential transformers, which control the movement of the table. Sensor 76 detects the position of table 32 for dressing, sensor (77) detects the grinding position for seat b, and the other sensor (78) the position for grinding the surface a. The table 32 is moved for a dressing infeed by rotation of the eccentric disc 64 and shaft 61 which is secured to a worm wheel 63 rotated stepwise by gearing driven through a one-way clutch by a pinion engaging a rack movable by a hydraulic cylinder, the stroke of the cylinder being controlled by an adjustable limit switch. The one-way clutch can be released so that operation of a screw 91 effects a manual dressing adjustment. Microswitches are mounted on the table stand 33 and are actuated by adjustable screws 98, 99, 100 on the table 32 to position the table for effecting infeed for dressing of rear wheels, detecting the maximum size of the dressed wheels, and detecting the minimum size of the wheels for grinding. The shaft 61 can also be rotated through gearing driven by a motor (103, Fig. 9, not shown). During dressing, the relative position between the grinding wheel 12 for grinding the seat surface b and the table 32 alters and is compensated by movement of the second table 8 through rotation of the cam follower 17 by a feed mechanism 106 having a hydraulic motor connected by a rack-and-pinion and one-way clutch to the shaft carrying the follower. The clutch can be released for manual adjustment. In operation, the first swivel table 9 is adjusted to the angle of the seat surface b of the workpiece and the second swivel table 13 is adjusted so that the grinding spindles 11, 12 are parallel to the workpiece spindle. The wheels 11<SP>1</SP>, 12<SP>1</SP> are dressed by moving the shift table 36 so that screw 41 engages abutment 43, advancing the dressing arm 46, and advancing table 3 by cylinder 5, and the disc 64 is then intermittently rotated so that the wheel 11<SP>1</SP> is dressed. The table 3 is retracted so that the dog 24 engages abutment 25b and clamp 31 is raised. Shift table 36 is moved to its alternate position and the second table is advanced by cylinder 16 and reciprocated for dressing the wheel 12<SP>1</SP>. After dressing, the arm 46 is raised and table 36 shifted to align the workpiece spindle 38 with spindle 11. Clamp 31 is lowered and the second table 8 fixed by engaging abutment 20. The table 3 and spindle 11 are reciprocated by rotation of cam 7c and the feed table 32 is advanced by movement of the lever 68. The table 32 is controlled by the sensors to effect rapid forward movement, rough grind, sparkout, return movement, dressing, rapid forward movement, first fine grinding, second fine grinding, spark-out and rapid return. When this surface a has been ground, table 3 is retracted and the intermediate abutment 27 and clamp 29 are raised to locate the table. The shift table 36 is moved to its other position and the second table 8 is advanced to insert the wheel 12<SP>1</SP> for grinding the seat surface b which is ground when the table 32 is advanced as for grinding the cylindrical surface a. In another embodiment, the machine has three spindles carrying wheels for grinding three surfaces on a workpiece, the position of the table 3 being determined by an additional intermediate abutment.