Title of Invention

"A MECHINE FOR ELECTROCHEMICALLY ASSISTED ARC MACHINING FOR 2-D SHAPE GENERATION".

Abstract

A machine for electrochemically assisted arc machining for 2-D shape generation which comprises a machine tool consisting of wire feeder mechanism which is mounted on a horizontal table holding frame, the said machine tool being mounted on an electrically insulated frame capable of horizontal movement to enable contact of traveling wire with a job to be machined, the said job being mounted on a horizontally moveable electrically insulated bed, the contact surface of the said traveling wire and the said job being provided with electrolyte supply through means such as one or more nozzles connected to an electrolyte tank , the said traveling wire and said job being electrically connected to negative and positive terminals respectively of a DC power source and the said machine being characterized in the use of wire feeder mechanism where in traveling wire being used as cathode and the said traveling wire having the freedom of rotation in a vertical, horizontal or inclined plane.

Full Text

The present invention relates to a machine for electrochemically assisted arc machining for 2-D shape generation. Electrochemically assisted arc machine is a non conventional cutting machine that can be used for fast cutting of billets, rods and sheets of metallic materials, which are difficult-to-cut by conventional methods. This machine has been developed by combining electrochemical dissolution and arcing processes in a novel electrolyte composition as described and claimed in our copending patent application No 477:DEL 2002..The machine for electrochemically assisted arc machining (ECAAM) for 2-D shape generation is useful for industrial applications, as conventional methods of cutting cannot be employed for machining difficult to cut super alloy materials such as Inconel, Nimonics, Stainless Steel, Titanium aluminide, tungsten carbide and heat treated high speed steel (HSS). The principle in this machine is that a travelling wire is used as cathode for 2-D shape generation by Programme Logic Controller (PLC). In mechanical engineering industry there is a need for cutting billets, rods and sheet stock of metallic materials and alloys prior to machining specific components. This operation proves to be time consuming especially with materials like stainless steel, nimonic etc. For cutting these, special alloy steel blades, diamond coated blades or slitting saws are used. This process proves to be costly because of the consumption of expensive tool. Flame cutting is also used for these metals. Disadvantages with flame cutting are a good bit of material is lost since the cut is quite wide and the method is well suited only for plates. Plasma arc or laser cutting also produce a cut edge with severe undulation. Super alloy materials such as Inconel, nimonics, Titanium aluminide and tungsten carbide cannot be cut easily by conventional methods. In the light of the above one can see that there is a need for fast cutting of difficult to cut hard metals of various sections into a desired shape. To the best of our knowledge and belief the very concept of combined arc and electrochemical machining is novel and as such is not known in the art. This has been confirmed as no literature or patents available for such a machine. The main object of the present invention is to provide a machine for electrochemically assisted arc machining for 2-D shape generation using a travelling wire as a cathode. Another object of the present invention is to provide a machine for electrochemically assisted arc machining for 2-D shape generation, which are difficult to cut materials of super alloys such as Inconel, Nimonics, Stainless Steels, Titanium aluminide, tungsten carbide and heat treated high speed steel (HSS) material. Still another object of the present invention is to provide a machine for electrochemically assisted arc machining for 2-D shape generation wherein the electrolyte used is as described and claimed in our copending patent application Yet another object of the present invention is to provide a machine for electrochemically assisted arc machining for 2-D shape generation wherein electrochemical dissolution and arcing processes are combined to provide machining of metallic materials which are difficult to cut by conventional methods. In the drawing accompanying this specification, figure 1 represents the schematic view of the machine of the present invention wherein the various parts are : 1 . CNC control panel 2. DC power source 3. Wire feeder mechanism for 2-D shape generation 4. Bed 5. Travelling wire 6. Horizontal table holding frame (Y-axis table) 7. Horizontal table holding bed for mounting job (X-axis table) 8. Electrolyte tank and pump. Figure 2 represents wire feeder mechanism for 2-D shape generation wherein the various parts are: 9. Wire take off spool 10. Fresh wire spool 11. Carbon brush 12. Current carrying roller (Drum) 13. Upper arm for wire length adjustment 14. Lower fixed arm for wire length adjustment 15. Guide pulleys for wire. Accordingly, the present invention provides a machine for electrochemically assisted arc machining for 2-D shape generation which comprises a machine tool essentially consisting of wire feeder mechanism for 2-D shape generation which is mounted on a horizontal table holding frame ( Y-axis table), the said machine tool being mounted on an electrically insulated frame capable of horizontal movement to enable contact of traveling wire with a job to be machined, the said job being mounted on a horizontally moveable electrically insulated bed, the contact surface of the said traveling wire and the said job being provided with electrolyte supply through means such as one or more nozzles connected to an electrolyte tank through a conventional chemical pump, the said traveling wire and said job being electrically connected to negative and positive terminals respectively of a DC power source and the said machine being characterized by a wire feeder mechanism where in traveling wire being used as cathode and the said traveling wire having the freedom of rotation in a vertical, horizontal or inclined plane . In an embodiment of the present invention the wire feeder mechanism consists of a supply spool and a take off spool which may be effected by an electric motor. In another embodiment of the present invention wherein the travelling wire used may be brass or copper or steel wire in a spool. In yet another embodiment of the present invention the prime mover used may be an electric motor. In still another embodiment of the present invention the horizontal movement of the frame mounted with machine tool may be effected by an electric motor. In further embodiment of the present invention the horizontal movement of the bed may be effected by an electric motor. In still further embodiment of the present invention the electrolyte used may be such as described and claimed in our copending patent application No:.477 DEL 2002. In still yet another embodiment of the present invention the brass or copper or steel wire is the cathode and the job is the anode. The present invention describes a machine for generating 2-D shapes using electrochemically assisted arc machining. In the present invention, a novel method of achieving fast cutting and shaping of metals and alloys by arcing in a specially formulated electrolyte composition was achieved. In this method, the cutting action is best described as electrochemically assisted arc machining. In other words, electrochemical dissolution and arcing alternatively take place resulting in fast cutting. The electrolyte composition formulated is able to play the dual role of permitting electrolyte dissolution of job as well as formation of arc on the job surface. The present invention describes a cutting machine for 2-D shape generation that can be used with the specially formulated electrolyte of copending patent Patent application No:-477DE2002 The machine for electrochemically assisted arc machining for 2-D shape generation consists of a DC power supply, a machine tool and an electrolyte circulation system. The power supply is a full wave rectifier without any smoothing. A thyristor controlled rectifier may also be used. The power supply has a short circuit protection and also a current limit. The machine tool consists of a wire transport mechanism which has a supply spool and a take off spool driven by a stepper motor. In the machining gap the wire travels vertically. The speeds of supply and take off spools are controlled to maintain the desired tension. Two spring loaded carbon brushes provide the electrical contact to the travelling wire through a current carrying roller (Drum). The travelling wire may be made to rotate in a vertical, horizontal or inclined plane. However, the preferred one is vertical. For cutting and the shape generation, the job is mounted on a horizontally moveable electrically insulated bed. The said travelling wire through a current carrying roller (Drum) and said job mounted table being electrically connected to negative and positive terminals respectively of a DC power supply. 8 The 2 axis programme logic controller (PLC) moves the horizontal X-Y table to generate the 2-D shape. The principle in this machine is that a travelling wire is used as cathode and the job is mounted on the horizontal X-axis table and the table is moved appropriately by PLC to generate the desired shape. Machining is accomplished by the electric current passing through the specially formulated electrolyte, which is pumped in the gap between the wire and job through one or more nozzles by chemical pump. The electrolyte flowing out of the gap is collected in a tank and is recirculated. The machine is provided with an enclosure to prevent splashing of electrolyte. The work enclosure is provided with an exhaust system to avoid spray of electrolyte from getting into the machining area. The main advantages of the present invention are : i. The electrochemically assisted arc machining (ECAAM) for 2-D shape generation is very useful for industrial applications, as conventional methods of cutting cannot be employed for machining difficult to cut super alloy materials. ii. The electrochemically assisted arc machining for 2-D shape generation can be used for fast cutting of difficult to cut hard metals of various sections into a desired shape. iii. The electrochemically assisted arc machining for 2-D shape generation can give higher productivity and it is not expensive. It is cost effective. iv. The electrolyte employed in the electrochemically assisted arc machining for 2-D shape generation is environmentally friendly, non-hazardous, non-polluting and safe to handle. v. The electrolyte used in the electrochemically assisted arc machining for 2-D shape generation is versatile, since it can be used for cutting all the ferrous materials. 10 We claim: 1. A machine for electrochemically assisted arc machining for 2-D shape generation which comprises a machine tool essentially consisting of wire feeder mechanism for 2-D shape generation which is mounted on a horizontal table holding frame ( Y-axis table), the said machine tool being mounted on an electrically insulated frame capable of horizontal movement to enable contact of traveling wire with a job to be machined, the said job being mounted on a horizontally moveable electrically insulated bed, the contact surface of the said traveling wire and the said job being provided with electrolyte supply through means such as one or more nozzles connected to an electrolyte tank through a conventional chemical pump, the said traveling wire and said job being electrically connected to negative and positive terminals respectively of a DC power source and the said machine being characterized in the use of wire feeder mechanism where in traveling wire being used as cathode and the said traveling wire having the freedom of rotation in a vertical, horizontal or inclined plane . 2. A machine for electrochemically assisted arc machining for 2-D shape generation as claimed in claim 1, wherein the wire feeder mechanism consists of a supply spool and a take off spool which is moved by an electric motor. 3. A machine for electrochemically assisted arc machining for 2-D shape generation as claimed in claim 1, wherein the travelling wire used is brass or copper or steel wire in a spool. 4. A machine for electrochemically assisted arc machining for 2-D shape generation as claimed in claim 1, wherein the electrolyte used is as described and claimed in our copending patent application No. 477DEL2002 5. A machine for electrochemically assisted arc machining for 2-D shape generation as claimed in claim 1, wherein the brass or copper or steel wire is the cathode and job is the anode. 6. A machine for electrochemically assisted arc machining for 2-D shape generation substantially as herein described with reference to the drawings accompanying this specification.

Documents:

479-del-2002-abstract.pdf

479-del-2002-claims.pdf

479-del-2002-correspondence-others.pdf

479-del-2002-correspondence-po.pdf

479-del-2002-description (complete).pdf

479-del-2002-drawings.pdf

479-del-2002-form-1.pdf

479-del-2002-form-19.pdf

479-del-2002-form-2.pdf

479-del-2002-form-3.pdf