| 摘要 |
PURPOSE:To enhance the accuracy of the parallelism of platens and ensure the parallelism which does not vary over a long period of time, by a structure wherein a large number of annular oil grooves are provided axially on the inner peripheral surface of the bearing part of the rod of a mold-clamping cylinder and on the outer peripheral surface of a piston extended from the rod. CONSTITUTION:Balancing grooves 20 serving as oil grooves are provided at a bearing part 5. A large number of annular V-grooves 26 serving as oil grooves are provided in the outer peripheral surface of the piston of a mold-clamping ram 2. Because pressure oil is fed from an oil pressure source 22 through pressure ports 21 to the respective balancing grooves 20... at all times so as to uniformly act radially in order to radially balance the oil pressure. A rod 3 supports a movable side platen 12 and a mold 13 in an overhung manner by means of its rigidity. Because the consequent side pressure applied to the bearing part 5 automatically balances, the parallelism between both the rod and the platen and mold is kept with no eccentricity. Further, because the pressure oil in the balancing grooves 20..., 26... balance automatically against the increase of their side pressures, the degree of horizontality of the rod 3 itself is kept correctly and consequently the parallelism of platens can be kept at all times. |
