An injection molding apparatus including a stack mold tool and a ball screw centering device. The stack mold tool including a stationary mold block, a center mold block movable relative to the stationary mold block, and a distal mold block movable relative to the center mold block. The ball screw centering device includes a center bearing housing connected to the center mold block, a rotatable shaft having a first side ball track and a second side ball track, a first nut coupled to the stationary mold block, the first nut including a track portion cooperating with the first side ball track to define a passage for a first set of ball bearings, and a second nut coupled to the distal mold block, the first nut including a track portion cooperating with the second side ball track to define a passage for a second set of ball bearings.

A mold clamping apparatus includes a mold clamping mechanism having a screw shaft, a crosshead, and a cylindrical cover member configured to house the screw shaft. The cover member includes a rear cover member arranged between a mold clamping housing and the crosshead and a front cover member arranged between the crosshead and a movable platen, and the rear cover member expands and contracts in accordance with change in a facing distance between the mold clamping housing and the crosshead caused by movement of the crosshead.

A clamping apparatus of an injection molding machine is provided. A first driving device operates a movable platen to perform mold opening/closing. A second driving device applies a clamping force to the movable platen. A screw mechanism converts rotational power of the driving devices into linear power. By contact/separation between a first rotation plate coupled to a screw shaft and a second rotation plate, a power transmission device switches transmission of power from the second driving device to the screw mechanism. At the normal time, an urging mechanism integrally moves the screw shaft and the first rotation plate in a mold closing direction and releases the connection of the second driving device. When the mold closing is completed, the urging mechanism allows the screw shaft and the first rotation plate to integrally move in a mold opening direction, and brings the second driving device into a connected state.

A plastic injection molding machine and molding method related to an injection molding machine for stack molds, wherein the central portion of the mold remains fixed and it has two molding faces that act on the fixed central portion by means of a hydraulic chamber that produces the clamping force and prevents the deformations due to bending on the molding faces. Likewise, it relates to a molding method.

A tandem mold for creating injection-molded parts from synthetic material includes a first part (2), a second part (4), a third part (6), and a guide (20, 22, 26, 28). A first parting surface is defined between the first part (2) and the third part (6), and a second parting surface is defined between the second part (4) and the third part (6). The mold also includes, for each parting surface, at least one mechanical stop (44) that is movable between a first position, where said stop prevents a drive mechanism from reaching the closed position of the mold, and a second position, or retracted position, where the mold can reach its closed position.

A mold clamping device includes two mold platens; a plurality of ball screw mechanisms connecting the mold platens to each other; and a plurality of servo motors configured to drive the respective ball screw mechanisms. Each of ball screws respectively configuring the plurality of ball screw mechanisms is provided with a cover which covers at least a part of the corresponding ball screw between the two mold platens.

In order to calculate a ball screw abrasion amount of an injection-axis ball screw or a mold-clamping-axis ball screw, a position of a ball nut fitted to the ball screw is photographed by a camera installed in an injection molding machine. Then, if the photographed position of the ball nut is found, as a result of analysis of an image captured by the camera, to be deviated from the position of the ball nut when a ball screw has no abrasion, it is determined that the ball screw is abraded.

A plastic injection molding machine and molding method related to an injection molding machine for stack molds, wherein the central portion of the mold remains fixed and it has two molding faces that act on the fixed central portion by means of a hydraulic chamber that produces the clamping force and prevents the deformations due to bending on the molding faces. Likewise, it relates to a molding method.

An injection molding machine capable of opening/closing a movable mold relative to a stationary mold by moving a crosshead backward and forward to move a movable platen backward and forward relative to a stationary platen through a toggle link. The injection molding machine includes a reciprocating mechanism that receives a counterforce exerted on the crosshead in the back-and-forth direction when the movable mold and the stationary mold are closed, and a load acquisition unit that acquires a load exerted on the reciprocating mechanism in a direction perpendicular to the back-and-forth direction of the crosshead.

Provided is a mold opening/closing device that can prevent a ball screw shaft from reaching a risky speed while using a ball screw having a cantilever supporting structure. A mold clamping device according to the present invention is provided with: a ball screw having a ball screw shaft and a ball screw nut that meshes with the ball screw shaft; and a motor that drives the ball screw. One end of the ball screw shaft is supported by a fixation plate or a movable plate so as to be rotatable or non-rotatable, while being restricted in movement in an axial direction and thereby serving as a fixed end, and the other end thereof serves as a free end. Further, the mold clamping device is characterized in that a distance between the ball screw nut and the fixed end is shorter than a distance between the fixed plate and the movable plate.