Tool Making and Die Sinking Machines

Tool Making and Die Sinking Machines

Tool Making and Die Sinking Machines - The making of press tools, drop forging dies, die casting moulds, moulds for plastics products, dies for hot brass pressings and for machine forging, often necessitates the machining of extremely complicated shapes.

 While a certain amount of above said work may be done on the standard machine tools of the tool room, there are many cases where special facilities (machines), as discussed in this chapter, must be provided.

Fig. shows a die impression.

Die Impression

In the formation of the elements of a die impression, shapes often occur which cannot be obtained by any of the usual machining processes. The only method of producing these is to rough them to the nearest shape by some machining process, and then finish them by hand. The hand methods to be adopted will, of course, depend on circumstances, but hammer and chisel, file, graver etc., will figure largely in the process.

In many cases, a special die impression may be formed by a contributory set of operations on different machines, and Fig. 28.1 shows a form which lends itself to standard machining with only a small amount of hand finishing. One sequence for machining this impression could be as follows: I. Bore out and recess one-half of the impression.

2. Bore out and recess the other half to break into the first machining.

3. End mill the upper recessed surfaces to match up with the turning.

4. End mill the sides of the hole with the job tilted to give the angle. Match up at the bottom of the holes.

5. Rough out the end slots by the best possible means.

6. Set at correct angles and machine the sloping slot sides as far as possible, using the diameter of a small end mill. (Alternatively these could be shaped or slotted.)

7. Mill the bottom of the slot as far as possible with the end of a small end mill.

8. Finish off by hand at the joining corners of the slots inaccessible to the machining processes used.

The following special machines for tool making and die-sinking will be discussed in this chapter.

1. Milling machine for tool and die makers.

2. Pantograph die sinking and engraving machine.

3. Hand duplicator.

4. Automatic die sinking and copy milling machine.