The COFA tool system has been the first and still unrivaled tool system for removing burrs on the front and back of a drilled through-hole on even and uneven surfaces in a single cycle. It radially removes the burrs off the bore edges, without requiring the work piece to be turned or the spindle to be stopped. These features also qualify it as a deburring tool for crossbores. COFAt can be applied universally in automatic operations for efficient and process capable high volume production but also manually.
- The COFA standard tool series ranges from bore diameter Ø2.0mm up to Ø26.0 mm. The cassette system is designed for bore diameters larger than Ø26 mm.
- The exchangeable carbide blades are carried out with material dependant coatings.
- The COFA system guarantees a consistent, radially shaped deburring of even and uneven bore edges.
- Tool types C6 up to C12 allow up to three different deburring sizes without changing the tool due to the exchangeable blade sizes.
- Machining of the bore edge without creating a secondary burr.
- The cassette solution intgrates the deburring process into an existing customer tool. By combining two or several processes in one single tool, the cycle time can be reduced considerably.
- The thread tool series has been optimized for easy center positioning of the screws.
The COFA blade is mounted spring-loaded in the tool body. In COFA C2 to 5M, the swivel movement is guided by a rollpin, whereas it is a blade holder for COFA C6 to C12 (illustrated below). This way, the cutting edge follows the uneven bore edge. The more the tool enters into the bore, the more the blade swings into the tool body. The result is a radially shaped consistent deburring of the bore edge.
1 - Tool body
2 - Spring
3 - Blade holder
4 - Blade Type C6 - C12
5 - Cutting edge forward
6 - Cutting edge backward
The process is very simple. First, rapid traverse of the cutting unit of the tool above the top material surface of hole or burr. Referencing the front edge of the cutting blade.
In working feed forward and with working speed, the deburring of the upper bore edge is carried out.
Once deburring is complete, traverse in rapid feed without stopping the spindle in the hole unless there are interfering edges such as a cross bore in the interior.
Despite of the swivel movement of the spindle, the ball shaped blade head glides softly on the surface without any damage. Not even reamed surfaces will suffer.
As soon as the blade swings out again at the back side of the work piece, the rapid feed is stopped.
In working feed, the deburring of the back bore edge is carried out. Once finished, traverse in rapid speed and without stopping the spindle out of the hole.
The COFA tool family consists of three different groups of tool types. It starts with COFA C2 and C3, followed by COFA 4M and 5M in the intermediate segment. COFA New Generation C6, C8, C12 representing the upper end of the range is the latest development.
The concepts differ because of the different tool dimensions. Whereas the blade and the blade holder form a unit in COFA C2/C3 and 4M/5M which is held in the tool body by a rollpin, it has been split into two seperate components in COFA New Generation.
The product range consists of tools for the use in bore diameters ranging from 2.0 mm to 26.0 mm. In addition, using cassettes, any size of bore diameter can be deburred. The deburring capacity (radially) is 0.1 up to 1.4 mm maximum depending on bore dimension and blade selection. Within the tool range, there are variants of diameters that cover a minimal bore diameter range.
|Bore||Max. Deburring Size||Tool Series|
|Ø 2.0 – Ø 3.1 mm||0.10 mm||C2|
|Ø 3.0 – Ø 4.1 mm||0.15 mm||C3|
|Ø 4.0 – Ø 5.0 mm||0.25 mm||COFA 4M|
|Ø 5.0 – Ø 6.0 mm||0.35 mm||COFA 5M|
|Ø 6.0 – Ø 8.4 mm||0.70 mm||C6|
|from Ø 10.0 mm||0.70 mm||C6 Cassette|
|Ø 8.0 – Ø 12.4 mm||0.90 mm||C8|
|from Ø 14.0 mm||0.90 mm||C8 Cassette|
|Ø 12.0 – 26.0 mm||1.40 mm||C12|
|from Ø 20.0 mm||1.40 mm||C12 Cassette|