Molding apparatus and die changing apparatus for exclusive die

A 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, and
• the fixed die and the movable die each include a general-use die of the same type and an exclusive die that forms a cavity, the exclusive die being removably coupled to the general use die, and further comprising:
• a pair of internal rails 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 the moveable rail can be moved into proximity to or away from the fixed rail.