Patent Number: 6,332,355

Title: Method of estimating a life of ball screw included in electric injection molding machine and life estimating system

Abstract: An injection unit including a heating barrel and an injection screw rotationally and axially movable and placed in the heating barrel is disposed on one side of a clamping mechanism for clamping a mold. The injection screw is driven and controlled for operation through a ball screw by an electric motor. Products, each of a moving speed of the ball screw and an operating current supplied to the electric motor in a unit time, are accumulated to calculate a total energy value indicating the amount of total energy supplied to the ball screw. A life energy value is predetermined on the basis of products, each of force generated by the ball screw and a moving speed of the ball screw. It is decided that a life of the ball screw has terminated when the total energy value A is equal to or greater than the life energy B (A.gtoreq.B).

Inventors: Totani; Tsuginobu (Numazu, JP), Sasaki; Kiyoshi (Mishima, JP), Kanda; Akira (Numazu, JP), Iimura; Yukio (Shimizu-Cho, JP), Koike; Jun (Shimizu-Cho, JP), Katoh; Fumiyuki (Nagaizumi-Cho, JP), Tamaki; Masahiro (Susono, JP), Yamaguchi; Yutaka (Kannami-Cho, JP)

Assignee: Toshiba Kikai Kabushiki Kaisha

International Classification: F16H 57/00 (20060101); G01N 17/00 (20060101); G01M 005/00 ()

Expiration Date: 12/25/2018