Method of and a device for the compaction of a powder into a cutting insert green body

Patent metadata

Field	Value
Publication number	US-9919359-B2
Application number	US-201515303659-A
Country	US
Kind code	B2
Filing date	Mar 20, 2015
Priority date	Apr 16, 2014
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A device for manufacturing a cutting insert green body by compacting a powder includes a first punch, a second punch having a punch edge that has a curvature around the circumference of the punch edge that is at least partially non-perpendicular with a pressing axis of the device, a first die part, and a second die part. When the first and second die parts are joined together when filling the die with powder, one of the first and second die parts is on top of the other and, when the device is in a position ready for filling of powder into the die, the device presents a cavity defined by the lower die part, a punch being introduced into the lower and upper die part. An opening in an upper end surface of the upper die part enables filling of the powder into the cavity.

First claim

The invention claimed is:

1. A method of compacting a powder into a cutting insert green body comprising the steps of:
providing a compaction device including a first punch; a second punch that presents an abutment surface for abutment with the powder to be compacted, an outer peripheral surface, and a punch edge disposed at an intersection between the abutment surface and the outer peripheral surface, wherein the punch edge presents a predetermined curvature around the circumference of the second punch; a first die part presenting a chamber having an inner peripheral surface which corresponds to a peripheral surface of a cutting insert green body to be compacted in said first die part, a bore for receiving said first punch, said bore extending from an opening in a first end surface of the first die part to said chamber, and an opening region extending with an expanding cross-section from said chamber to an opposite second end surface of the first die part and defining an opening in said opposite second end surface; a second die part presenting a bore for receiving said second punch, said bore extending from an opening in a first end surface of the second die part to a second end surface thereof, thereby defining an opening in said second end surface, wherein an edge that defines said opening in the second end surface of the first die part has a curvature corresponding to the predetermined curvature of said punch edge of the second punch;
arranging the second end surface of the first die part and the second end surface of the second die part contiguously such that said opening in the second end surface of the first die part meets said opening of the second end surface of the second die part;
positioning the device such that one of said first and second die parts is contiguously arranged above the other die part;
arranging said first end surface of the one of the die parts being arranged above the other die part such that it extends rectilinearly in at least one direction;
introducing one of said punches into the bore of the one of the die parts being arranged below the other die part, wherein said predetermined curvature of the punch edge of the second punch is at least partly non-perpendicular to a pressing axis of the device and that the edge of the opening in the second end surface of the first die part presents a corresponding curvature with regard to said pressing axis; and
filling powder into a cavity defined by the one of the die parts being arranged below the other die part, the punch introduced therein and the one of the die parts being arranged above the other die part by introducing the powder through the opening in the first end surface of the one of the die parts being arranged above the other die part; and
compacting the powder.

2. A method according to claim 1 , wherein the step of compacting the powder includes introducing into said cavity by advancing the other of said first and second punches through the opening in the first end surface of the one of the first and second die parts being arranged above the other die part towards said chamber to a final compacting position.

3. A method according to claim 1 , wherein the step of compacting the powder includes introducing into said cavity by advancing the second punch through the second die part until the punch edge is at a distance from said inner peripheral surface of said chamber of the first die part so short that an edge of the compacted green body will be formed in the region in which said punch edge is adjacent to said inner peripheral surface.

4. A method according to claim 3 , wherein the second punch is advanced until the distance between the punch edge and the inner peripheral surface of the chamber in the first die part is equal to or less than 50 μm, equal to or less than 30 μm, equal to or less than 10 μm, or equal to or less than 5 μm.

5. A method according to claim 1 , further comprising the steps of exposing the compacted cutting insert green body by retracting the first die part from the second die part, and displacing the compacted green body from the first die part through the opening in the second end surface thereof.

6. A method according to claim 1 , further comprising the step of providing a region around said opening in the second end surface of the second die part with a curvature corresponding to the curvature of the edge that defines the opening in the second end surface of the first die part, such that the second surface of the second die part will be in a sealing relation with said edge of the first die part when the first die part is contiguously arranged in relation to the second die part.

7. A method according to claim 1 , further comprising the step of providing a powder-filling device and positioning it on top of said opening in the first end surface of the upper die part or removing it from said position by permitting it to slide on said first end surface of the upper die part in said direction in which said surface extends rectilinearly.

8. A method according to claim 1 , wherein the compacted cutting insert green body has the shape of a positive cutting insert, and that the inner peripheral surface of said chamber in the first die part has a corresponding shape, with a cross section cross wise to the pressing axis that increases towards the opening in the second end surface of the first die part.

9. A device for manufacturing a cutting insert green body by compacting a powder, said device comprising:
a first punch;
a second punch that presents an abutment surface for abutment with the powder to be compacted, an outer peripheral surface, and a punch edge at an intersection between the abutment surface and the outer peripheral surface, wherein the punch edge presents a predetermined curvature around the circumference of the second punch;
a first die part, presenting a chamber having an inner peripheral surface which corresponds to a peripheral surface of a cutting insert green body to be compacted in said first die part, a bore for receiving said first punch, said bore extending from an opening a first end surface of the first die part to said chamber and an opening region extending with an expanding cross-section from said chamber to an opposite second end surface of the first die part and defining an opening in said opposite second end surface;
a second die part, presenting a bore for receiving said second punch, said bore extending from an opening in the first end surface of the second die part to a second end surface of the second die part, thereby defining an opening in said second end surface, wherein an edge that defines said opening in the second end surface of the first die part has a curvature corresponding to the predetermined curvature of said punch edge of the second punch, the second end surface of the first die part being configured to be contiguously arranged in relation to the second surface of the second die part such that said opening in the second end surface of the first die part meets said opening in the second end surface the second die part, wherein, when the first and second die parts are contiguously arranged to each other in connection to filling of powder into the die, one of said first and second die parts is arranged above the other, said first end surface of the one of the die parts being arranged above the other die part extends rectilinearly in at least in one direction, said predetermined curvature being at least partly non-perpendicular to a pressing axis of the device and that the edge of the opening in the second end surface of the first die part presents a corresponding curvature with regard to said pressing axis; and
when the device is in a position ready for filling of powder into the die, it presents a cavit

Assignees

• Seco Tools Ab
• Sandvik Intellectual Property

Inventors

• Sterkenburg Dirk

Classifications

• B22F2005/001

  Cutting tools, earth boring or grinding tool other than table ware · CPC title

• B22F5/10

  of articles with cavities or holes, not otherwise provided for in the preceding subgroups · CPC title

• B30B15/32

  Discharging presses · CPC title

• B30B15/304

  by using feed frames or shoes with relative movement with regard to the mould or moulds · CPC title

• B22F2003/033

  with multiple punches working in the same direction · CPC title