Showa Denko K.k.

Toshiba Machine Co., Ltd.

Tohoku Munekata Co., Ltd

Munekata Co., Ltd.

Atsuhiro Suzuki

Shigeru Fujita

Kiyoshi Sasaki

Hiroshi Katsuta

Motoyuki Hirata

Yasumasa Sugiyama

Hirofumi Tateyama

Hiroshi Okuyama

Kazuhiro Tashiro

Shogo Ishibashi

Kazuyuki Ushizaka

In the filling step, the forward movement speed of the screw is controlled in accordance with a predetermined speed pattern until the screw reaches a deceleration initiation point, LS B. After the screw reaches LS B, a deceleration step is started. In the deceleration step, the forward movement speed of the screw is controlled in a feedback manner such that the internal pressure of the mold reaches a predetermined target pressure. When the screw reaches a pressure holding initiation point, LS (or pressure holding initiation time, TR ), the pressure holding step is started. In the pressure holding step, the target pressure, which is a function of time, is changed with time in accordance with a program. When the operation goes to the pressure holding step, the set of PID coefficients within the feedback control loop are replaced by different set of PID coefficients.

Method for controlling the forward movement speed of the screw in an injection molding machine

A reference pressure of melted material injected to a mold cavity of a mold is set as a function of injection passing time from a start of an injecting process or a function of a distance of movement of an injection plunger, and the movement of the plunger is started at a temporarily constant injection speed. A correction value of the injection speed is obtained to eliminate a difference between a sensed pressure of the melted material injected to the mold cavity of the mold and the reference pressure in a range that the sensed pressure of the melted material exceeds the reference pressure during the injection passing time from the start of the injection process wherein the plunger is started to move or during the movement of the plunger, and the injection speed is corrected in accordance with the corrected value. The corrected value of the injection speed, and the injection passing time from the start of the injection process or the distance of the movement of the plunger, those of which corresponding to the range, are memorized in a memory unit, and are characterized to a desired injection speed pattern, and the pattern is read out from the memory unit as an injection molding speed condition.

Method for automatically setting injection molding speed condition in

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Fukushima, Japan

Atsuhiro Suzuki