Magnetic clamping device, an injection moulding machine comprising such a device and a method for manufacturing such a device

• US 20070290780A1
• Filed: 06/08/2007
• Published: 12/20/2007
• Est. Priority Date: 06/16/2006
• Status: Active Grant

• Current Assignee: Staubli Faverges (Stã¤Ubli Holding AG)
• Original Assignee: Staubli Faverges (Stã¤Ubli Holding AG)
• Inventors: Tiberghien, Alain-Christophe, Brun, Eric
• Granted Patent: US 7,782,164 B2
• Time in Patent Office: Days
• US Class Current: 335/285
• CPC Class Codes: B25B 11/002 Magnetic work holders
• CPC Class Codes: B29C 33/305 Mounting of moulds or mould support plates handling of moulds B29C31/006; mounting of moulds for injection moulding B29C45/1742
• CPC Class Codes: B29C 45/1742 Mounting of moulds; Mould supports mounting of exchangeable mould inserts B29C45/2675
• CPC Class Codes: H01F 7/04 Means for releasing the attractive force

Abstract

This magnetic clamping device comprises a clamping support (41) and at least one magnetic pad (5) housed in this support, each pad comprising a magnet that can be switched between an activated state, in which the magnetic flux lines generated by the pad may extend towards the outside of the clamping device, and a deactivated state, in which the magnetic flux lines are confined in the clamping device. Each pad (5) comprises at least one solenoid coil, each end of this solenoid coil being connected to a terminal. The terminals of at least one pad (5) are connected to a circuit by means of removable connectors (7A, 7B, 9).

Claims

1. Magnetic clamping device comprising a clamping support and at least one magnetic pad housed in this support, each pad comprising a magnet that can be switched between an activated state, in which the magnetic flux lines generated by the pad may extend towards the outside of the clamping device, and a deactivated state, in which the magnetic flux lines are confined in the clamping device, each pad comprising at least one solenoid coil, each end of this solenoid coil being connected to a terminal, wherein the terminals of at least one pad are connected to a circuit by means of removable connectors.

2. Magnetic clamping device according to claim 1, wherein each pad comprises a solenoid coil for measuring the magnetic flux generated by the pad, each end of the measurement solenoid coil being connected to a measurement terminal, the measurement terminals of at least one pad being connected to a magnetic flux measurement circuit by means of removable connectors.

3. Magnetic clamping device according to claim 2, comprising reference pads whose measurement terminals are connected in series to form a first flux measurement circuit, the measurement terminals of the other pads being connected in series to form a second flux measurement circuit, the measurement terminals in the first and second measurement circuits being connected to one another and to a control unit by means of the said removable connectors.

4. Magnetic clamping device according to claim 3, wherein each pad comprises a continuity terminal and is connected to at least one adjacent pad in the support by means of one of the said connectors, this connector being of a first type when it connects two pads of the same kind amongst the reference pads and the other pads, and of a second type when it connects two pads of different kinds.

5. Magnetic clamping device according to claim 4, wherein a connector of the said first type connects together terminals of the same kind amongst the measurement terminals and the continuity terminals of two adjacent pads, while a connector of the said second type connects together terminals of different kinds of two adjacent pads.

6. Magnetic clamping device according to claim 1, wherein each pad comprises a switchable magnet comprising a permanent magnet surrounded by a power solenoid coil, each end of the power solenoid coil being connected to a power terminal, the power terminals of at least one pad being connected to a power circuit by means of removable connectors.

7. Magnetic clamping device according to claim 4, wherein each pad comprises a switchable magnet comprising a permanent magnet surrounded by a power solenoid coil, each end of the power solenoid coil being connected to a power terminal, the power terminals of at least one pad being connected to a power circuit by means of removable connectors, and wherein the said connectors comprise at least one plug furnished with three pins for connection respectively to a measurement terminal, a continuity terminal and a power terminal of a pad.

8. Magnetic clamping device according to claim 4, wherein each pad comprises a switchable magnet comprising a permanent magnet surrounded by a power solenoid coil, each end of the power solenoid coil being connected to a power terminal, the power terminals of at least one pad being connected to a power circuit by means of removable connectors, and wherein each terminal of a pad extends over an angular sector with an apex angle greater than or equal to 40°

, each pad comprising at least two connection portions for connecting a connector, each connection portion extending over an angular sector with an apex angle greater than or equal to 45°

, the said connector being capable of being connected simultaneously to three terminals, respectively a measurement terminal, a continuity terminal and a power terminal, on each of said connection portions.

9. Magnetic clamping device according to claim 8, wherein the relative radial distance between the measurement terminals and power terminals of a pad on the one hand, and the relative radial distance between the power terminals and continuity terminal, on the other hand, is constant in each connection portion and identical from one connection portion to another.

10. Magnetic clamping device according to claim 4, wherein each pad comprises a switchable magnet comprising a permanent magnet surrounded by a power solenoid coil, each end of the power solenoid coil being connected to a power terminal, the power terminals of at least one pad being connected to a power circuit by means of removable connectors, and wherein each pad comprises two semicircular measurement terminals and two semicircular power terminals, the continuity terminal of each pad being of circular shape and closed, the measurement terminals, continuity terminal and power terminals being placed concentrically relative to one another.

11. Magnetic clamping device according to claim 10, wherein each pad comprises a cylindrical insulating casing, this casing comprising three concentric circumferential grooves for receiving, respectively, the measurement terminals, the continuity terminal and the power terminals of the said pad.

12. Magnetic clamping device according to claim 10, wherein the ends of the measurement solenoid coil are connected to each measurement terminal in a mid-zone of the latter.

13. Magnetic clamping device according to claim 1, wherein the support comprises housings for receiving pads and housings for receiving connectors.

14. Injection moulding machine, comprising a magnetic clamping device according to claim 1.

15. Method for manufacturing a magnetic clamping device according to claim 1, comprising the steps of:

a) inserting pads into housings of the support and immobilizing these pads relative to the support;

b) connecting the pads to one another and to a control unit by inserting removable connectors into housings of the support in such a way as to place the connector pins in contact with the terminals of the pads.