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US-20260124675-A1 - MONITORING DEVICE AND MONITORING METHOD

US20260124675A1US 20260124675 A1US20260124675 A1US 20260124675A1US-20260124675-A1

Abstract

A monitoring device includes an acquisition unit configured to acquire acceleration information of a plunger during an injection operation, a determination unit configured to determine presence of an abnormality in a drive mechanism that drives the plunger in a case where a variation width of an acceleration of the plunger in a traveling direction exceeds a value that is predetermined and in a case where a variation frequency of the acceleration of the plunger in the traveling direction includes a component of a frequency that is predetermined, and an output unit configured to output a determination result of the determination unit.

Inventors

  • Tomohiro Koyama

Assignees

  • TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date
20260507
Application Date
20251021
Priority Date
20241101

Claims (5)

  1. 1 . A monitoring device comprising: an acquisition unit configured to acquire acceleration information of a plunger during an injection operation; a determination unit configured to determine presence of an abnormality in a drive mechanism that drives the plunger when both of following conditions are satisfied: a variation width of an acceleration of the plunger in a traveling direction exceeds a value that is predetermined, and a variation frequency of the acceleration of the plunger in the traveling direction includes a component of a frequency that is predetermined; and an output unit configured to output a determination result of the determination unit.
  2. 2 . The monitoring device according to claim 1 , wherein the determination unit is configured to determine presence of the abnormality in the drive mechanism that drives the plunger when both of following conditions are satisfied: the variation width of the acceleration of the plunger in the traveling direction exceeds the value that is predetermined, and during an acceleration measurement period, the variation frequency of the acceleration of the plunger in the traveling direction continuously includes the component of the frequency that is predetermined.
  3. 3 . The monitoring device according to claim 2 , wherein the determination unit is configured to determine presence of an abnormality other than in the drive mechanism that drives the plunger when either of following conditions is satisfied even when the variation width of the acceleration of the plunger in the traveling direction exceeds the value that is predetermined: the variation frequency of the acceleration of the plunger in the traveling direction includes the component of the frequency that is predetermined only during a part of the acceleration measurement period, or during the acceleration measurement period, the variation frequency of the acceleration of the plunger in the traveling direction does not include the component of the frequency that is predetermined.
  4. 4 . The monitoring device according to claim 1 , wherein the determination unit is configured to further determine presence or absence of galling of at least either a plunger sleeve or the plunger based on information on an acceleration in a direction perpendicular to the traveling direction of the plunger among the acceleration information.
  5. 5 . A monitoring method comprising: acquiring acceleration information of a plunger during an injection operation; determining presence of an abnormality in a drive mechanism that drives the plunger when both of following conditions are satisfied: a variation width of an acceleration of the plunger in a traveling direction exceeds a value that is predetermined, and a variation frequency of the acceleration of the plunger in the traveling direction includes a component of a frequency that is predetermined; and outputting a result of the determining.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2024-192633 filed on November 1, 2024. The disclosure of the above-identified application, including the specification, drawings, and claims, is incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a monitoring device and a monitoring method. 2. Description of Related Art An injection molding machine, also referred to as a die casting machine, is required to detect various abnormalities that affect the injection of a molten metal by a plunger and to quickly repair the abnormalities in order to provide a high-quality molded product. A technique related to the die casting machine is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2020-138209 (JP 2020-138209 A). A die casting machine disclosed in JP 2020-138209 A includes acceleration sensors that are capable of detecting an acceleration in three axial directions and provided on a plunger sleeve and at least one of a plunger tip or a plunger rod. Chatter (vibration) generated due to galling (abrasion) of the plunger sleeve or the plunger tip is detected from accelerations in a vertical direction detected by the acceleration sensors. SUMMARY The abnormalities that affect the injection of the molten metal by the plunger include not only the galling but also an abnormality of a drive mechanism that drives the plunger. However, in JP 2020-138209 A, abnormalities other than the galling, among the abnormalities that affect the injection of the molten metal by the plunger, cannot be detected. The present disclosure has been made in view of the above background, and provides a monitoring device and a monitoring method capable of specifying a location where an abnormality that affects injection of a molten metal by a plunger occurs. A monitoring device according to the present disclosure includes: an acquisition unit configured to acquire acceleration information of a plunger during an injection operation; a determination unit configured to determine presence of an abnormality in a drive mechanism that drives the plunger when both of the following conditions are satisfied: a variation width of an acceleration of the plunger in a traveling direction exceeds a value that is predetermined, and a variation frequency of the acceleration of the plunger in the traveling direction includes a component of a frequency that is predetermined; and an output unit configured to output a determination result of the determination unit. The monitoring device according to the present disclosure can accurately detect the abnormality of the drive mechanism that drives the plunger. That is, the monitoring device according to the present disclosure can detect abnormalities other than galling, among abnormalities that affect the injection of the molten metal by the plunger. Since the injection molding machine can perform the repair of an abnormality location as necessary based on a monitoring result of the monitoring device according to the present disclosure, a high-quality molded product can be provided. A monitoring method according to the present disclosure includes: acquiring acceleration information of a plunger during an injection operation; determining presence of an abnormality in a drive mechanism that drives the plunger when both of the following conditions are satisfied: a variation width of an acceleration of the plunger in a traveling direction exceeds a value that is predetermined, and a variation frequency of the acceleration of the plunger in the traveling direction includes a component of a frequency that is predetermined; and outputting a result of the determining. The monitoring method according to the present disclosure can accurately detect the abnormality of the drive mechanism that drives the plunger. That is, the monitoring method according to the present disclosure can detect abnormalities other than galling, among abnormalities that affect the injection of the molten metal by the plunger. Since the injection molding machine can perform the repair of an abnormality location as necessary based on a monitoring result in the monitoring method according to the present disclosure, a high-quality molded product can be provided. According to the present disclosure, it is possible to provide a monitoring device and a monitoring method capable of specifying a location where an abnormality that affects the injection of the molten metal by the plunger occurs. BRIEF DESCRIPTION OF THE DRAWINGS Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: FIG. 1 is a schematic cross-sectional view showing the injection molding machine to which the monitoring device according to the present disclosure is applied; FIG