Die-clamping apparatus with aligning device

Molding apparatus comprising:

• a stationary die plate for holding a stationary die, a movable die plate for holding a movable die,
• an opening/closing hydraulic cylinder for moving said movable die plate forwardly/rearwardly with respect to said stationary die plate to thereby open/close the dies,
• a die-clamping hydraulic cylinder comprising a hollow piston slidably positioned in a hydraulic chamber in said stationary die plate,
• a tie bar for clamping said movable die and said stationary die by the die-clamping force generated by said die-clamping hydraulic cylinder, said tie bar extending through said hollow piston, and
• an alignment mechanism associated with said tie bar so as to join said movable die and said stationary die via said tie bar in such a manner that alignment of the movable die held on said movable die plate and the stationary die held on said stationary die plate can be performed, said alignment mechanism comprising a flexible first alignment device connecting a portion of said tie bar to the end of said hollow piston remote from said movable die plate regardless of the position of said movable die plate, wherein said flexible first alignment device comprises a first hydraulic actuator positioned between said hollow piston and said portion of said tie bar, said first hydraulic actuator having a housing forming a hydraulic chamber and a piston rod slidably positioned in the hydraulic chamber of said first hydraulic actuator, with said housing of said first hydraulic actuator being mounted to one of said hollow piston and said portion of said tie bar and said piston rod of said first hydraulic actuator being mounted to the other of said hollow piston and said portion of said tie bar, and means for applying hydraulic fluid under pressure to said hydraulic chamber of said first hydraulic actuator.

Molding apparatus comprising:

• a stationary die plate for holding a stationary die,
• a movable die plate for holding a movable die,
• an opening/closing hydraulic cylinder for moving said movable die plate forwardly/rearwardly with respect to said stationary die plate to thereby open/close the dies,
• a die-clamping hydraulic cylinder comprising a hollow piston slidably positioned in a hydraulic chamber in said stationary die plate,
• a tie bar for clamping said movable die and said stationary die by the die-clamping force generated by said die-clamping hydraulic cylinder, said tie bar extending through said hollow piston,
• a movable die plate support member extending through a hole in said movable die plate for supporting said movable die pate, the diameter of said hole in said movable die plate being greater than the diameter of the portion of said movable die plate support member in said hole so as to provide a gap between said movable die plate and said movable die plate support member, wherein said tie bar extends through a hole in said movable die plate support member to said stationary die plate to guide said movable die plate support member and to provide for clamping said movable die and said stationary die by the die-clamping force generated by said die-clamping hydraulic cylinder, wherein said movable die plate support member is elongated along the axis of said tie bar from said movable die plate toward said stationary die plate, and wherein regardless of the position of the movable die plate said tie bar extends beyond the end of said movable die plate support member which is remote from said stationary die plate, thereby extending the distance along which said movable die plate support member is supported on said tie bar and providing greater accuracy of the alignment of the movable die plate with respect to the stationary die plate,
• a first alignment mechanism associated with said tie bar so as to join said movable die and said stationary die via said tie bar in such a manner that alignment of the movable die held on said movable die plate and the stationary die held on said stationary die plate can be performed, said first alignment mechanism comprising a flexible first alignment device connecting a portion of said tie bar to the end of said hollow piston remote from said movable die plate regardless of the position of said movable die plate, and
• a second alignment device, said second alignment device joining said movable die plate to said movable die plate support member in such a manner that the alignment of said movable die plate with respect to said tie bar can be performed, and at least two ball bearings positioned between said movable die plate support member and said tie bar at spaced apart locations along the length of said tie bar, thereby permitting said movable die plate to slide in the axial direction of said tie bar in response to the action of the opening/closing hydraulic cylinder while using the tie bar as a guide.

Molding apparatus comprising:

• a stationary die plate for holding a stationary die,
• a movable die plate for holding a movable die,
• an opening/closing hydraulic cylinder for moving said movable die plate forwardly/rearwardly with respect to said stationary die plate to thereby open/close the dies,
• a die-clamping hydraulic cylinder,
• movable die plate support member extending through a hole in said movable die plate for supporting said movable die plate, the diameter of said hole in said movable die plate being greater than the diameter of the portion of said movable die plate support member in said hole so as to provide a gap between said movable die plate and said movable die plate support member,
• a tie bar extending through a hole in said movable die plate support member to said stationary die plate to guide said movable die plate support member and to provide for clamping said movable die and said stationary die by the die-clamping force generated by said die-clamping hydraulic cylinder,
• wherein said movable die plate support member is elongated along the axis of said tie bar from said movable die plate toward said stationary die plate, and wherein regardless of the position of the movable die plate said tie bar extends beyond the end of said movable die plate support member which is remote from said stationary die plate, thereby extending the distance along which said movable die plate support member is supported on said tie bar and providing greater accuracy of the alignment of the movable die plate with respect to the stationary die plate, and
• a first alignment device joining said movable die plate to said movable die plate support member in such a manner that the alignment of said movable die plate with respect to said tie bar can be performed, and at least two ball bearings positioned between said movable die plate support member and said tie bar at spaced apart locations along the length of said tie bar, thereby permitting said movable die plate to slide in the axial direction of said tie bar in response to the action of the opening/closing hydraulic cylinder while using the tie bar as a guide.