Metal stamping tool with a hybrid magnetorheological-nitrogen spring

Patent metadata

Field	Value
Publication number	US-10408296-B2
Application number	US-201615053444-A
Country	US
Kind code	B2
Filing date	Feb 25, 2016
Priority date	Feb 25, 2016
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A metal stamping tool includes a hybrid magnetorheological-nitrogen spring including a housing having an interior wall defining an interior volume. A fixed divider separates the interior volume into a nitrogen gas chamber and a magnetorheological fluid chamber. A piston extends into both the nitrogen gas chamber and the magnetorheological fluid chamber. The piston defines a magnetorheological fluid gap within the magnetorheological fluid chamber. An electric coil positioned adjacent the fluid gap to apply a magnetic field to magnetorheological fluid within the fluid gap when the electric coil is energized.

First claim

What is claimed is:

1. A metal stamping tool comprising:
a hybrid magnetorheological-nitrogen spring including a housing having an interior wall defining an interior volume;
a fixed divider separating the interior volume into a nitrogen gas chamber and a magnetorheological fluid chamber;
a piston extending into both the nitrogen gas chamber and the magnetorheological fluid chamber and defining a magnetorheological fluid gap within the magnetorheological fluid chamber;
an electric coil positioned adjacent the fluid gap to apply a magnetic field to magnetorheological fluid within the fluid gap when the electric coil is energized.

2. The metal stamping tool of claim 1 , wherein the hybrid magnetorheological-nitrogen spring is coupled to at least one of a binder and a pad of the stamping tool.

3. The metal stamping tool of claim 1 , wherein the electric coil is carried by the piston.

4. The metal stamping tool of claim 3 , wherein an outer wall of the piston surrounds the electric coil and defines a portion of the fluid gap.

5. The metal stamping toot of claim 1 , wherein the electric coil has a pre-discontinuity state in which a pre-discontinuity current is supplied to the coil causing the spring to exhibit a pre-discontinuity force-to-travel ratio and a post-discontinuity state in which a post-discontinuity current is supplied to the coil causing the spring to exhibit a post-discontinuity force-to-travel ratio.

6. The metal stamping tool of claim 5 , wherein the pre-discontinuity current is zero.

7. The metal stamping tool of claim 5 , wherein the spring exhibits a change from the pre-discontinuity state to the post-discontinuity state that is substantially instantaneous.

8. The metal stamping tool of claim 5 , wherein the tool has an operating state in which a stamping speed of the tool does not need to be altered during a change from the pre-discontinuity state to the post-discontinuity state.

9. The metal stamping tool of claim 5 , wherein the tool has an operating state in which a current supplied to the coil is alternated between the pre-discontinuity current and the post discontinuity current.

Assignees

• Zhou Dajun
• Fca Us Llc

Inventors

• Zhou Dajun

Classifications

• F16F9/535

  Magnetorheological [MR] fluid dampers (springs comprising magnetorheological [MR] elastomers F16F1/361) · CPC title

• F16F9/061

  Mono-tubular units · CPC title

• B21D24/08 Primary

  Pneumatically or hydraulically loaded blank holders · CPC title

• F16F13/002 Primary

  comprising at least one fluid spring (F16F13/005, F16F13/02, F16F13/04 take precedence) · CPC title