US 6,805,827 B2 · Mold clamping device, method of increasing/decreasing pressure for such device, and mold releasing method

Abstract

A stationary platen (14) and a movable platen (18), which are connected with each other by tie rods (28), to which metallic molds are respectively attached, are opened and closed by an electrically driven ball screw mechanism. The movable platen is composed of a platen body and a pressure plate (304) attached to the platen body which can be contacted with and separated from the platen body. Between the movable platen and the pressure plate, clamping is conducted by the expansion and contraction of a bladder (318) into which hydraulic oil for clamping can be introduced. The bladder houses an insert die (320), the shape of which is identical with an internal shape of the bladder, and a hydraulic oil path is formed in the insert die. While a ball screw member (102) of an electrically driven ball screw mechanism is being supported being capable of moving in the axial direction, a brake means (130) for restricting rotation is provided, and a mold releasing cylinder mechanism (116) is connected. The mold releasing cylinder mechanism is operated when it shares a hydraulic pressure supply source for supplying hydraulic pressure to the bladder and the hydraulic oil path is changed over.

Claims23

Dependent claims

A clamping device comprising:

a movable platen having a movable metallic mold, capable of going forward and back;
a stationary platen having a stationary metallic mold, arranged being opposed to the movable platen;
and
an opening and closing operation mechanism for opening and closing the movable and the stationary platen respectively having the movable and the stationary metallic mold, the movable and the stationary platens being connected with each other by tie rods,
the clamping device further comprising a pressurizing mechanism,
the pressurizing mechanism including:
a pressure plate arranged between the stationary platen and the stationary metallic mold, the stationary metallic mold being attached to the pressure plate;
a piston slidably arranged in a cylinder provided in the stationary platen, the piston being capable of protruding toward the pressure plate;
a bladder arranged between the piston and the cylinder in the stationary platen, the bladder being capable of clamping the movable and the stationary metallic molds via the piston when the bladder is expanded and contracted by supplying and discharging hydraulic pressure;
and
a soft protective member interposed between the piston and the bladder and capable of closing a gap between them when the bladder is expanded.

8 more elements

A control method of increasing and decreasing hydraulic pressure for clamping in which metallic molds are closed by a stationary platen and a movable platen, which are connected with each other by tie rods, to which the metallic molds are respectively attached, and hydraulic pressure is introduced into a pressurizing mechanism capable of pushing out a pressure plate attached to the platen body, the pressure plate being capable of coming into contact with and separating from the platen body, wherein

after hydraulic pressure has been increased to a clamping pressure when the rotation of a piston pump is controlled in the case of increasing hydraulic pressure so as to supply hydraulic oil to the pressurizing mechanism, the hydraulic pressure is contained on the pressurizing mechanism side, after that, hydraulic pressure in a hydraulic oil path on the upstream side of the pressure containing position is smoothly decreased by controlling a reverse speed of the piston pump, after the hydraulic pressure has been sufficiently decreased, the piston pump is stopped,
after hydraulic pressure has been increased to a clamping pressure when the rotation of a piston pump is controlled in the case of decreasing hydraulic pressure so as to supply hydraulic oil to the pressurizing mechanism, the hydraulic pressure is contained on the pressurizing mechanism side, and the piston pump is operated and hydraulic pressure in a hydraulic oil path on the upstream side of the hydraulic pressure containing position is increased so that the hydraulic pressure before the pressure containing position and the hydraulic pressure after the pressure containing position can be equivalent to each other, after the pressure containing has been released, hydraulic pressure in a hydraulic oil path on the upstream side of the pressure containing position is smoothly decreased by controlling a reverse speed of the piston pump, and hydraulic pressure is released to the tank side via the piston pump.

Dependencies are inferred from the claim text.

Mold clamping device, method of increasing/decreasing pressure for such device, and mold releasing method

Life of this patent

Mold clamping device, method of increasing/decreasing pressure for such device, and mold releasing method

Life of this patent

Abstract

Claims23