Method and device for manufacturing a cutting insert green body

Patent metadata

Field	Value
Publication number	US-9956702-B2
Application number	US-201414901132-A
Country	US
Kind code	B2
Filing date	Jul 4, 2014
Priority date	Jul 5, 2013
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A method and device for manufacturing a cutting insert green body, the method includes the step of providing a compression tool having an upper and lower die, and an upper and lower punch. The upper die defines a punch tunnel in which the upper punch slides, and the lower die defines a punch tunnel in which the lower punch slides. The dies define a die cavity to accommodate a powder to be compressed by action of the respective punches to form the green body. Powder in the die cavity is compressed by forwarding the upper punch through the punch tunnel of the upper die and a predetermined distance L through the opening of the lower die. The upper die is displaced relative to the opening of the lower die and the upper punch is removed from the lower die to move the green body out of the lower die through the opening thereof.

First claim

The invention claimed is:

1. A method for manufacturing a cutting insert green body by compressing a powder, comprising the steps of
providing a compression tool having an upper die and a lower die, an upper punch and a lower punch, wherein the upper die defines a punch tunnel in which the upper punch is arranged to slide, and the lower die defines a punch tunnel in which the lower punch is arranged to slide, and wherein the dies, when joined together define a die cavity provided to accommodate a powder to be compressed by action of the respective punches for the forming of said green body;
providing the lower punch in a predetermined position in the punch tunnel of the lower die;
filling powder into an open cavity defined in the lower die;
joining the upper and lower dies such that an opening of the upper die meets and communicates with a corresponding opening of the lower die and such that said cavity filled with powder in the lower die forms part of said die cavity;
compressing the powder in said die cavity by action of said punches, wherein said upper punch is forwarded through the punch tunnel of the upper die and is forwarded a predetermined distance L through said opening of the lower die and into the lower die, whereby said green body is formed;
displacing the upper die relative the opening of the lower die, thereby providing for more space for the green body to exit through; and
removing the upper punch from the lower die, and moving the green body out of the lower die through said opening of the lower die, wherein the die cavity defined by the dies has a vertical centre axis and that, in the region of said opening of the lower die, an inner peripheral surface of the lower die has an inclination angle α relative to said centre axis such that an inner circumference of the inner peripheral surface of the lower die increases towards said opening thereof, wherein the upper punch presents an abutment surface for abutment against the powder, an outer peripheral surface, and a punch edge at an intersection between the abutment surface and the outer peripheral surface, wherein the upper punch is forwarded the distance L into the lower die such that there is a remaining gap g between said inner peripheral surface of the lower die and said punch edge, wherein 0 μm<g≤30 μm, wherein the level of the punch edge will define an upper edge of the green body, and wherein the upper edge is formed where said inner peripheral surface intersects a plane of the abutment surface of the upper punch.

2. A method according to claim 1 , wherein the opening of the upper die is smaller than the opening of the lower die, such that the upper die overlaps the opening of the lower die with a distance l when the dies are joined.

3. A method according to claim 2 , wherein l≤55 μm.

4. A method according to claim 1 , wherein L≥50 μm.

5. A method according to claim 1 , wherein 2°≤α≤30°.

6. A method according to claim 1 , wherein in the region of the opening of the upper die, there is formed a gap k between an outer peripheral surface of the upper punch and an inner peripheral surface of the upper die, wherein k<50 μm.

7. A method according to claim 1 , wherein the green body is moved out of the lower die either by withdrawal of the lower die while the lower punch is maintained in its position, or by ejection of the lower punch through the lower die while the latter is maintained in its position, or a combination thereof.

8. A device for manufacturing a cutting insert green body by compressing a powder, said device comprising:
a compression tool including an upper die and a lower die, an upper punch and a lower punch, wherein the upper die defines a punch tunnel in which the upper punch is arranged to slide, and the lower die defines a punch tunnel in which the lower punch is arranged to slide, and wherein the dies, when joined, together define a die cavity provided to accommodate a powder to be compressed by action of the respective punches for the forming of said green body, the upper and lower dies each having a respective opening such that an opening of the upper die meets and communicates with a corresponding opening of the lower die when the upper and lower dies are joined, whereby the upper punch is arranged so as to be forwarded a predetermined distance L through said opening of the lower die and into the lower die upon compaction of the powder, and whereby the upper die is displaceable relative to the opening of the lower die, and being arranged so as to be displaced relative said opening of the lower die before removal of said green body through said opening of the lower die, thereby providing for more space for the green body to exit through, wherein the die cavity defined by the dies has a vertical centre axis and that, in the region of said opening of the lower die, an inner peripheral surface of the lower die has an inclination angle α relative to the centre axis such that an inner circumference of the inner peripheral surface of the lower die increases towards said opening thereof, wherein the upper punch presents an abutment surface for abutment against the powder, an outer peripheral surface, and a punch edge at an intersection between the abutment surface and the outer peripheral surface, and wherein the upper punch is arranged to be forwarded the distance L into the lower die such that there is a remaining gap g between said inner peripheral surface of the lower die and said punch edge, wherein 2°≤α≤30°, wherein the level of the punch edge will define an upper edge of the green body, and wherein the upper edge is formed where said inner peripheral surface intersects a plane of the abutment surface of the upper punch.

9. A device according to claim 8 , wherein the opening of the upper die is smaller than the opening of the lower die, such that the upper die overlaps the opening of the lower die with a distance/when the dies are joined.

10. A device according to claim 9 , wherein l≤55 μm.

11. A device according to claim 8 , wherein L≥50 μm.

12. A device according to claim 8 , wherein in the region of the opening of the upper die, there is formed a gap k between an outer peripheral surface of the upper punch and an inner peripheral surface of the upper die, wherein k<50 μm.

Assignees

• Sandvik Intellectual Property

Inventors

• Bolander Christer
• Lindskog Per
• Larsson Johan

Classifications

• B30B11/027

  Particular press methods or systems · CPC title

• B22F3/03 Primary

  Press-moulding apparatus therefor · CPC title

• B30B15/022

  Moulds for compacting material in powder, granular of pasta form · CPC title

• B22F3/02

  Compacting only · CPC title

• B28B7/10

  Moulds with means incorporated therein, or carried thereby, for ejecting {or detaching} the moulded article ({flexible moulds bent open for ejecting B28B7/06; ejecting by tilting or inverting the mould B28B7/08; } devices, not forming part of the mould, for ejecting the moulded article B28B13/06) · CPC title