9 PROCESSING OF WORKPIECES ON PLANING AND TANNING

MACHINES

9.1 Characteristics of the planing and tanning process

Planing and boring machines are mainly intended for processing flat and

shaped surfaces with a straight line, located in horizontal, vertical, and inclined

planes, as well as for processing grooves such as, for example, dovetail, machine T-

shaped, rectangular, etc. .

When planing, the tool (in transverse planing machines) or the workpiece (in

longitudinal planing machines) performs a reciprocating main movement in the

horizontal plane.

When hammering, the main movement – reciprocating movement of the tool –

is carried out in the vertical plane.

Cutters are a tool for planing or finishing. In their shape, planing cutters are

similar to lathe cutters, but since they work in more difficult conditions (at the

moment of cutting the cutter there is an impact), the holders make them more

massive. Planing cutters, as well as turning cutters, are divided by the location of the

cutting edge on the right and the left ; according to purpose - for passing, cutting,

cutting , shaped; according to the nature of processing - on rough and final.

During processing, the planing cutter bends and the top of the straight cutter,

describing an arc, sinks into the body for preparation, which leads to damage to the

processed surface. Therefore, planing cutters are usually bent so that the axis of the

cutter holder passes through its top.

9.2 Works performed on planing machines

With planing, processing accuracy of 8...13 qualities is obtained with surface

roughness R z = 80...20, and with fine planing - R a = 2.5...1.5.

In fig. 31 shows examples of work performed on planing machines. Horizontal

planes are treated with passing cutters (Fig. 9.1, a, b), vertical planes (Fig. 9.1, c) -

with passing or undercutting cutters fixed in the cutter holder, which can be turned

at some angle to the treated surface. Inclined planes are treated with passing or

undercutting cutters (Fig. 9.1, d). Grooves and grooves are processed with bent and

slotted cutters. For example, slotted (Fig. 9.1, e ), right and left bent cutters (Fig. 9.1,

f ), and chamfered cutter (Fig. 9.1, g) are successively used for processing machine

T -shaped grooves .

Wide cutters 6 (Fig. 9.1) are used for smooth planing of guide frames, slabs,

and tables . The cutting depth in this case is 0.05...0.1 mm and such planing can be

the final finish.

Figure 9.1 – Examples of planing works

It should be noted that all such surfaces can also be processed by milling, which

is a more productive process, but in those cases when the final processing is planing,

for example, when processing direct beds of metal-cutting machines, preference

should be given to planing, after which the planing process is carried out much easier

than after milling.

Сontrol questions:

1. What is the main movement in planing and finishing?

2. What tool is used for planing and finishing?

3. What works can be performed on planing and tanning machines?