Pressing device

Patent metadata

Field	Value
Publication number	US-12447707-B1
Application number	US-202318861524-A
Country	US
Kind code	B1
Filing date	May 16, 2023
Priority date	Jun 13, 2022
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A piston axial force information detection unit ( 53 ) detects piston axial force information pertaining to an axial force applied to a piston body ( 21 ). A friction information storage unit ( 62 ) stores friction information pertaining to a frictional force between a piston seal ( 23 ) and a pressure vessel ( 10 ) when the piston body ( 21 ) moves relative to the pressure vessel ( 10 ). A drive control unit ( 65 ) controls a drive device ( 40 ) on the basis of the piston axial force information and the friction information. In a holding stroke for controlling the pressure inside the pressure vessel ( 10 ) so as to be constantly held, the drive control unit ( 65 ) controls the drive device ( 40 ) so that the piston body ( 21 ) reciprocates with respect to the pressure vessel ( 10 ).

First claim

The invention claimed is:

1. A pressing device comprising:
a pressure vessel;
a piston body fitted into an inside of the pressure vessel movably in an insertion direction and an extraction direction relative to the pressure vessel;
a piston seal provided in the piston body and configured to seal a gap between the piston body and the pressure vessel;
a piston axial force information detection unit configured to detect piston axial force information pertaining to an axial force applied to the piston body in a movement direction of the piston body relative to the pressure vessel;
a driving device configured to move the piston body relative to the pressure vessel;
a friction information storage unit configured to store friction information pertaining to a frictional force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel; and
a drive control unit configured to control the driving device based on the piston axial force information detected by the piston axial force information detection unit, and the friction information stored in the friction information storage unit,
wherein in a holding stroke for controlling a pressure inside the pressure vessel so as to be constantly held, the drive control unit controls the driving device so that the piston body performs a reciprocating motion relative to the pressure vessel.

2. The pressing device according to claim 1 ,
wherein the friction information storage unit stores the friction information when the piston body moves in the insertion direction relative to the pressure vessel, and the friction information when the piston body moves in the extraction direction relative to the pressure vessel, and
the drive control unit selects the friction information corresponding to a direction of movement of the piston body relative to the pressure vessel, and controls the driving device based on the selected friction information.

3. The pressing device according to claim 1 ,
wherein the friction information storage unit stores the friction information of each of movement speeds in a plurality of patterns of the piston body relative to the pressure vessel, and
the drive control unit selects the friction information corresponding to a movement speed of the piston body relative to the pressure vessel, and controls the driving device based on the selected friction information.

4. The pressing device according to claim 1 , further comprising
a piston position information detection unit configured to detect position information of the piston body relative to the pressure vessel.

5. The pressing device according to claim 1 ,
wherein the piston axial force information detection unit further includes a strain gauge that is mounted on the piston body to detect strain of the piston body.

6. The pressing device according to claim 1 ,
wherein the driving device includes:
a fluid pressure cylinder configured to move the piston body by a fluid pressure;
a fluid pressure detection unit configured to detect a fluid pressure supplied to the fluid pressure cylinder; and
a fluid pressure control unit configured to control an operation of the fluid pressure cylinder based on the fluid pressure detected by the fluid pressure detection unit,
wherein the piston axial force information detected by the piston axial force information detection unit includes the fluid pressure detected by the fluid pressure detection unit.

7. The pressing device according to claim 1 ,
wherein in the holding stroke, the drive control unit controls the driving device so that a reciprocating distance in the reciprocating motion of the piston body relative to the pressure vessel gradually decreases.

8. The pressing device according to claim 1 , further comprising
a pressure detection member provided removably from the pressure vessel, and configured to detect a pressure inside the pressure vessel,
wherein the friction information is acquired based on the piston axial force information detected by the piston axial force information detection unit, and the pressure inside the pressure vessel detected by the pressure detection member when the piston body moves relative to the pressure vessel.

9. The pressing device according to claim 8 ,
wherein the pressure detection member is disposed inside the pressure vessel removably from an inside of the pressure vessel, and
the friction information is acquired with the pressure detection member disposed inside the pressure vessel.

Assignees

• Kobe Steel Ltd

Inventors

• Nakai Tomomitsu
• Maegawa Akinori

Classifications

• B30B11/002

  Isostatic press chambers; Press stands therefor · CPC title

• B30B1/32

  by plungers under fluid pressure · CPC title

• B30B15/16 Primary

  Control arrangements for fluid-driven presses (pumps per se F04; hydraulic accumulators per se F15B; valves per se F16K; control devices in general G05) · CPC title

• B30B5/02 Primary

  wherein the pressing means is in the form of a flexible element, e.g. diaphragm, urged by fluid pressure · CPC title