Mold clamping device, injection molding machine, and offset load inspection method for mold clamping device

Patent metadata

Field	Value
Publication number	US-12583157-B2
Application number	US-202318331299-A
Country	US
Kind code	B2
Filing date	Jun 8, 2023
Priority date	Jun 15, 2022
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

A mold clamping device includes at least two mold platens and a plurality of rod-shaped members connecting two of the mold platens. An offset load detector is provided for at least one of the rod-shaped members at a connection portion between the at least one of the rod-shaped members and at least one of the mold platens. The offset load detector is configured to detect loads at two or more different detection positions, respectively, in a circumferential direction of the at least one of the rod-shaped members.

First claim

What is claimed is:

1 . A mold clamping device comprising:
at least two mold platens; and a plurality of rod-shaped members, the plurality of rod-shaped members connecting two of the mold platens, tension being generated in the plurality of rod-shaped members during mold clamping, wherein an offset load detector is provided for at least one of the rod-shaped members at at least one of connection portions between the at least one of the rod-shaped members and the mold platens, and wherein the offset load detector is configured to detect loads at two or more different detection positions, respectively, in a circumferential direction of the at least one of the rod-shaped members.

2 . The mold clamping device according to claim 1 , wherein the offset load detector is provided for all of the rod-shaped members at at least one of the respective connection portions between the rod-shaped members and the mold platens.

3 . The mold clamping device according to claim 1 , wherein at least one position of the two or more different detection positions of the offset load detector is disposed on a side of the rod-shaped member facing a center of the one mold platen, and another one of the two or more different detection positions is disposed on a side of the rod-shaped member away from the center of the one mold platen.

4 . The mold clamping device according to claim 1 ,
wherein each of the rod-shaped members includes a ball screw, wherein a ball nut attached to the ball screw is provided on one of the two mold platens, and wherein a servo motor, which is configured to rotate the ball screw, is provided on the other of the two mold platens.

5 . The mold clamping device according to claim 4 , wherein the offset load detector is provided between the ball nut and the one of the two mold platens.

6 . The mold clamping device according to claim 1 , wherein the offset load detector is configured by a load cell.

7 . The mold clamping device according to claim 1 , further comprising:
a control device configured to:
monitor the respective loads detected at the two or more different detection positions of the offset load detector; and
in a case where a difference between the loads exceeds a threshold set in advance, determine that there is an abnormality.

8 . An injection molding machine comprising:
a mold clamping device configured to clamp a mold; and an injection device configured to inject an injected material, wherein the mold clamping device comprises:
at least two mold platens; and
a plurality of rod-shaped members,
wherein the plurality of rod-shaped members connects two of the mold platens, tension being generated in the plurality of rod-shaped members during mold clamping, wherein an offset load detector is provided for at least one of the rod-shaped members at at least one of connection portions between the at least one of the rod-shaped members and the mold platens, and wherein the offset load detector is configured to detect loads at two or more different detection positions, respectively, in a circumferential direction of the at least one of the rod-shaped members.

9 . The injection molding machine according to claim 8 , wherein the offset load detector is provided for all of the rod-shaped members at at least one of the respective connection portions between the rod-shaped members and the mold platens.

10 . The injection molding machine according to claim 8 , wherein at least one position of the two or more different detection positions of the offset load detector is disposed on a side of the rod-shaped member facing a center of the one mold platen, and another one of the two or more different detection positions is disposed on a side of the rod-shaped member away from the center of the one mold platen.

11 . The injection molding machine according to claim 8 ,
wherein each of the rod-shaped members includes a ball screw, wherein a ball nut attached to the ball screw is provided on one of the two mold platens, and, wherein a servo motor, which is configured to rotate the ball screw, is provided on the other of the two mold platens.

12 . The injection molding machine according to claim 11 , wherein the offset load detector is provided between the ball nut and the one of the two mold platens.

13 . The injection molding machine according to claim 8 , wherein the offset load detector is configured by a load cell.

14 . The injection molding machine according to claim 8 , further comprising:
a control device configured to:
monitor the respective loads detected at the two or more different detection positions of the offset load detector; and
in a case where a difference between the loads exceeds a threshold set in advance, determine that there is an abnormality.

15 . An offset load inspection method for a mold clamping device,
the mold clamping device comprising:
at least two mold platens; and
a plurality of rod-shaped members, the plurality of rod-shaped members connecting two of the mold platens, tension being generated in the plurality of rod-shaped members during mold clamping,
the method comprising:
at at least one of connection portions between at least one of the rod-shaped members and the mold platens, detecting loads at two or more detection positions, respectively, in a circumferential direction of at least one of the rod-shaped members;
monitoring a difference between the detected loads; and
in a case a difference between the detected loads exceeds a threshold set in advance, determining that there is an abnormality.

16 . The mold clamping device according to claim 1 , wherein the offset load detector is a first offset load detector, and
wherein a second offset load detector and a third offset load detector are provided for at least one of the rod-shaped members at at least one of connection portions between the at least one of the rod-shaped members and the mold platens, and wherein the second offset load detector is configured to detect a component in a x-direction with respect to an offset load generated during the mold clamping together with the first offset load detector, and the third offset load detector is configured to detect a component in a y-direction with respect to the offset load generated during the mold clamping together with the first offset load detector.

17 . The mold clamping device according to claim 1 , wherein the offset load detector is configured to detect loads at two or more different detection positions, respectively, which are disposed on a same circumference in the circumferential direction of a same rod-shaped member among the at least one of the rod-shaped members.

18 . The mold clamping device according to claim 17 , wherein the offset detector comprises two or more two discrete load cells provided at the two or more different positions, where an offset load is calculated based on a difference between the detected loads detected by the two or more discrete load cells.

19 . The injection molding machine according to claim 8 , wherein the offset load detector is configured to detect loads at two or more different detection positions, respectively, which are disposed on a same circumference in the circumferential direction of a same rod-shaped member among the at least one of the rod-shaped members, and the offset detector comprises two or more two discrete load cells provided at the two or more different positions, where an offset load is calculated based on a difference between the detected loads detected by the two or more d

Assignees

• Japan Steel Works Ltd

Inventors

• Mitani Souma

Classifications

• B29C45/7653 Primary

  mould clamping forces · CPC title

• B29C2945/76013

  Force · CPC title

• B29C2945/76224

  Closure or clamping unit · CPC title

• B29C45/66 Primary

  mechanical · CPC title