Clinching method and tool for performing the same

Patent metadata

Field	Value
Publication number	US-9259774-B2
Application number	US-201113099932-A
Country	US
Kind code	B2
Filing date	May 3, 2011
Priority date	May 3, 2011
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A first layer is established on a second layer and an induction coil is disposed within induction proximity to the second layer. The induction coil is electrically energized thereby heating the second layer to a target temperature. A die having a die cavity is translated from a first location spaced substantially beyond an induction heating distance from the induction coil to a clamping location adjacent the second layer such that the induction coil surrounds a predetermined location on an external surface of the die. The die is heated by induction between the induction coil and the die while the die is translated toward the clamping location until the die reaches a predetermined die temperature. The induction coil is de-energized after the die has reached the predetermined die temperature. The first layer and the second layer are clamped between a binder and the die.

First claim

The invention claimed is:

1. A clinching tool, comprising:
a retractable punch;
a clinching die, including:
a die cavity defined in the clinching die, the die cavity having an aperture, a reaction surface opposed to the punch, an annular recess with an outer diameter substantially equal to an outer diameter of the aperture, the recess surrounding the reaction surface and extending axially deeper into the clinching die than the reaction surface; and
a support surface circumscribing the aperture, the support surface configured to receive a first layer overlapping a second layer;
an induction coil having an annular end surface and an internal surface; and
a binder having an aperture defined therein, the binder configured to clamp the first layer overlapping the second layer to the support surface while the punch is advanced toward the die and as the punch is retracted;
wherein the first layer is established on the second layer and the second layer is disposed within induction proximity of the induction coil, and the second layer is heated to a target temperature, after which the die is translated relative to the induction coil along the center axis to a clamping location adjacent the second layer such that the induction coil surrounds the die circumferentially around an external diameter of the die at a predetermined axial location on the die.

2. The clinching tool defined in claim 1 wherein the induction coil is configured to heat the die to a predetermined die temperature, and the clinching tool is configured to press the punch into the first layer forming a depression in the first layer and the second layer thereby compressing the first layer and the second layer together between the punch and the clinching die, thereby causing a portion of the second layer to extrude into the annular recess and simultaneously causing a portion of the first layer to radially extrude into an annular volume previously occupied by the second layer thereby forming an interlocking assembly of the first layer and the second layer.

3. The clinching tool defined in claim 1 wherein the induction coil substantially defines a cylinder.

4. The clinching tool defined in claim 1 wherein the induction coil is configured to induce heat selectably axially or radially.

5. The clinching tool defined in claim 1 wherein the induction coil is configured to induce heat simultaneously axially and radially in selectable proportions.

6. The clinching tool defined in claim 1 wherein the predetermined die temperature is between about 300 degrees C. and about 500 degrees C.

7. The clinching tool defined in claim 1 wherein the target temperature is between about 250 degrees C. and about 350 degrees C.

8. The clinching tool defined in claim 1 wherein the induction proximity is between about 1 mm and about 5 mm.

9. The clinching tool defined in claim 1 wherein the first layer is formed from a first material, and the second layer is formed from a second material different from the first material.

10. The clinching tool defined in claim 9 wherein the first material is one of aluminum and an aluminum alloy, and the second material is one of magnesium and a magnesium alloy.

11. A method of using the clinching tool of claim 1 , comprising:
establishing the first layer on the second layer on the support surface;
disposing the induction coil within induction proximity to the second layer;
electrically energizing the induction coil thereby heating the second layer to the target temperature;
translating the die having the die cavity relative to the induction coil from a first location spaced substantially beyond an the induction heating distance from the induction coil to clamping location adjacent the second layer such that the induction coil surrounds the die circumferentially around the external diameter of the die at the predetermined axial location on the die;
heating the die by induction between the induction coil and the die while translating the die toward the clamping location and until the die reaches a predetermined die temperature;
de-energizing the induction coil after the die reaches the predetermined die temperature; and
clamping the first layer and the second layer between a binder and the die.

12. The method defined in claim 11 , further comprising:
pressing a retractable punch through the aperture defined in the binder into the first layer, thereby forming a depression in the first layer and the second layer;
compressing the first layer and the second layer together between the punch and the clinching die;
radially extruding a portion of the second layer into an annular recess defined in the die adjacent the die cavity and concentric with the die cavity while simultaneously radially extruding a portion of the first layer into an annular volume previously occupied by the second layer thereby forming an interlocking assembly of the first layer and the second layer;
withdrawing the punch from the interlocking assembly;
withdrawing the interlocking assembly from the die cavity; and
translating the die to the first location.

13. The method defined in claim 11 wherein the induction coil substantially defines a cylinder.

14. The method defined in claim 11 wherein the die is substantially formed from tool steel.

15. The method defined in claim 13 wherein the induction coil induces heat selectably axially or radially.

16. The method defined in claim 13 wherein the induction coil induces heat simultaneously axially and radially in selectable proportions.

17. The method defined in claim 11 wherein the predetermined die temperature is between about 300 degrees C. and about 500 degrees C., and the target temperature is between about 250 degrees C. and about 350 degrees C.

18. The method defined in claim 11 wherein the induction proximity is between about 1 mm and about 5 mm.

19. The method defined in claim 11 wherein the first layer is formed from a first material and the second layer is formed from a second material that is different from the first material.

20. The method defined in claim 19 wherein the first material is one of aluminum and an aluminum alloy, and the second material is one of magnesium and a magnesium alloy.

Assignees

• Carter Jon T
• Gm Global Tech Operations Inc

Inventors

• Carter Jon T

Classifications

• H05B6/101

  for local heating of metal pieces · CPC title

• B21D39/031 Primary

  Joining superposed plates by locally deforming without slitting or piercing · CPC title