Abstract

The invention relates to the production of the grooves in barrels by means of a PECM (precise electrochemical machining) method. In known solutions, the barrels are inserted into and clamped in the PECM tool in a horizontal position. A disadvantage of this is that the prevalent gravitation can cause undesired effects (long, thin barrels can deflect or sag somewhat depending on the clamping situation). In addition, horizontal machine tools require a relatively large amount of space. The problem addressed by the invention is that of eliminating the aforementioned disadvantages of the known solutions. The design of the tool was thoroughly revised such that the barrels can be inserted into the tool in a vertical position and therefore gravitational effects are entirely eliminated. This design also makes it possible to reduce the space required by the machine tool. Because of the design of said tool, one or more barrels can be inserted and machined simultaneously, which reduces the machining time. Barrels up to a length of 1500 mm can be produced by means of said tool.

IPC Classes  ?

• B23H 9/00 - Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects
• F41A 21/18 - GroovesRifling
• B23H 3/00 - Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte
• B23H 9/14 - Making holes

Abstract

The present invention relates to a method for rifling the barrels of firearms using a barrel (6) as a workpiece (6), which in its longitudinal direction defines an axis A and has a bore that lies in the longitudinal direction and defines an inner wall of the barrel, and a tool (8) having a tool head (10) with an outer contour that corresponds to the shape of the rifling to be produced and that consists of an electrically conductive material. An electrolyte solution is pumped through the bore of the barrel (6) while the tool (8) is guided through the bore of the barrel (6), and a pulsed electrical voltage is applied to the workpiece (6) and the tool (8) and generates a direct current, the workpiece (6) representing the anode and the tool head (10) the cathode. The barrel (6) is positioned vertically with its longitudinal direction. A gap extends around the tool head (10) between the electrically conductive outer contour of the tool head (10) and the inner wall of the barrel (6) and the electrolyte solution flows through said gap. During the application of the pulsed voltage the tool (8) is moved through the bore of the barrel (6) relative to the workpiece (6) and is rotated at the same time about the axis A, thereby producing the rifling on the inner wall of the bore. The invention also relates to a device for carrying out the method.

IPC Classes  ?

• B23H 9/00 - Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects
• F41A 21/18 - GroovesRifling
• B23H 3/00 - Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte
• B23H 9/14 - Making holes