MAGNETIC FIXING DEVICE

• US 20100013583A1
• Filed: 06/26/2007
• Published: 01/21/2010
• Est. Priority Date: 02/23/2007
• Status: Active Grant

• Current Assignee: Pascal Engineering Corporation.
• Original Assignee: Pascal Engineering Corporation.
• Inventors: Kimura, Seiji
• Granted Patent: US 8,031,038 B2
• Time in Patent Office: Days
• US Class Current: 335/294
• CPC Class Codes: B29C 2045/1746 using magnetic means
• CPC Class Codes: B29C 45/1742 Mounting of moulds; Mould supports mounting of exchangeable mould inserts B29C45/2675

Abstract

The magnetic fixing device comprises a clamping plate having a fixing surface to which a clamping object is fixed and plural magnetic force generation mechanisms. The magnetic force generation mechanisms each comprise a magnetic material member facing the fixing surface, plural permanent magnets arranged around the outer periphery of the magnetic material member, a first Alnico magnet placed on the back of the magnetic material member, and a first coil for switching the polarity of the first Alnico magnet, and can be switched between the absorption state in which the clamping object is adsorbed and the non-absorption state in which the clamping object is not adsorbed. An operation state indication mechanism capable of presenting an indicator indicating that the plural magnetic force generation mechanisms are in the absorption state or in the non-absorption state is provided on the fixing surface or outer periphery of the clamping plate.

Claims

1. A magnetic fixing device comprising a clamping plate having a fixing surface for fixing a clamping object such as a mold and plural magnetic force generation mechanisms installed in the clamping plate for fixing the clamping object to the fixing surface by magnetic force, characterized in that:

each of the magnetic force generation mechanisms comprises a magnetic material member facing said fixing surface, plural permanent magnets arranged around an outer periphery of the magnetic material member, a first Alnico magnet provided on a back of the magnetic material member, and a first coil for switching a polarity of said first Alnico magnet, and can be switched between an absorption state in which the clamping object is adsorbed and a non-absorption state in which the clamping object is not adsorbed, and

an operation state indication mechanism capable of presenting an indicator indicating that said plural magnetic force generation mechanisms are in the adsorption state or in the non-adsorption state is provided on the fixing surface or outer periphery of said clamping plate.

2. The magnetic fixing device according to claim 1 wherein said operation state indication mechanism comprises a casing member installed in said clamping plate, a transparent cover member closing a front of the casing member, a first housing pit formed in said casing member, a second Alnico magnet housed in the first housing pit, a second coil wound around the second Alnico magnet, and a movable indication member consisting of a permanent magnet housed in a second housing pit formed in said casing member on a front side of the first housing pit;

and

an energizing circuit that energizes the second coil only while the plural first coils of said plural magnetic force generation mechanisms are energized is provided.

3. The magnetic fixing device according to claim 2 wherein said movable indication member is made of a disc-shaped permanent magnet that can be turned around in said second housing pit and said indicators are provided on end faces of said disc-shaped permanent magnet.

4. The magnetic fixing device according to claim 2 wherein said movable indication member is made of a cylindrical permanent magnet that can be turned around in said second housing pit, said indicators are provided on end faces of said cylindrical permanent magnet, and a pin member rotatably supporting said cylindrical permanent magnet at the longitudinal midpoint is provided.

5. The magnetic fixing device according to claim 2 wherein said movable indication member is made of a cylindrical permanent magnet housed in said second housing pit in a manner that it is axially movable by a predetermined stroke and said indicators are provided on end faces of the cylindrical permanent magnet.

6. The magnetic fixing device according to any of claims 1 to 5 wherein

said magnetic fixing device is mounted on a platen of an injection molding machine.