Patent ID: 7604037
Filing Date: 2009-10-20
Classification: B29C,F15B

Abstract:
1. A change over method for performing change over of an exclusive die of a molding apparatus, the molding apparatus including a fixed plate supporting a fixed die; a movable plate supporting a movable die; a plurality of tie bars inserted through and extending from the fixed plate and the movable plate; die opening-closing means that moves the movable plate forward and backward with respect to the fixed plate thus opening and closing the movable die with respect to the fixed die; first tie bar fixing means that removably fixes one end portion of each of the tie bars to the fixed plate; second tie bar fixing means that removably fixes an other end of each of the tie bars to the movable plate when in a closed die position; a die clamping cylinder which is provided near to tie bar insertion holes of the fixed plate or the movable plate and which generates a clamping force that pushes the movable plate toward the fixed plate side using the first or the second tie bar fixing means and the tie bars; and a tie bar removal cylinder that moves each of the tie bars in a removal direction from the fixed plate, wherein the die opening-closing means includes a motor and a movement conversion mechanism that converts rotation of the motor to linear movement that is transmitted to a support plate on which the movable plate is mounted, the support plate being disposed on a base stand via a linear movement guide, and the die opening-closing means being disposed between the support plate and the base stand, the fixed die and the movable die each include a general-use die of the same type and the exclusive die that forms a cavity, the exclusive die being removably coupled to the general use die, and a pair of internal rails are provided which guide movement of a change over carriage for changing over the exclusive dies the pair of internal rails comprising a fixed rail and a movable rail, wherein each rail is positioned below the tie bars on a lower side and between the fixed plate and the movable plate, the pair of internal rails extending in a direction that intersects with the tie bars, on one side, the fixed rail is fixedly disposed at a front surface of the fixed plate and, on an other side, the movable rail is disposed such that it can be moved into proximity to or away from the fixed rail, the change over method comprising: after the movable plate is moved back to an open die position by the die opening-closing means, releasing the fixing of the fixed plate side to the tie bars on the lower side while the tie bar removal cylinders are activated so as to remove the tie bars on the lower side from the fixed plate, and replacing the exclusive die by moving the change over carriage using the internal rails as a guide.