The physical basis of the metal cutting process. Chip formation process. Build-up on cutting tools. The device of the main components of lathes.
The workshop of the plant.
The cutter removes a layer of metal on the part.
The metal is a polycrystal.
Cartoon explaining the structure of metal, changes in it when exposed to metal.
A cartoon explaining the processes occurring in metal when exposed to it with a cutter and the formation of chips.
The chip moves along the normal to the shear plane.
If the normal passes outside the cutting wedge of the cutter, the chips after deformation come out of contact with the cutter and curl freely.
If the normal passes inside the cutting wedge of the cutter, then the chips cannot move freely, because they collide with the front surface of the cutter and are additionally deformed.
Due to the chip pressure on the cutter and the high temperature, the particles of the deformable metal are inhibited.
A cartoon explaining the concept of a stagnant zone, a build-up and the reasons affecting the work of the cutter.
During finishing work, the appearance of an excrescence is undesirable.
The growth is formed most intensively when working with plastic metals.
Then the joint or drain chips are obtained.
When processing brittle metals, such as cast iron or bronze, the growth is not retained on the cutter.
Cartoon explaining the deformation of the incisor.
Increasing the cleanliness class of the front surface of the tool, achieved by careful sharpening and fine-tuning, the use of appropriate coolant reduces the intensity of the formation of growths.
The cutting speed has a great influence on the formation of the growth.
When processing carbon steel at a speed of 20-30 meters per minute, intensive growth formation occurs.
A sample of an incisor with a similar growth.
At lower speeds, the temperature in the cutting zone is insufficient for welding deformed metal particles, so no build-up is formed.
When working at high speeds, the temperature in the cutting zone increases significantly, as a result of which the growth becomes plastic and practically disappears.
A thin over-incisor layer is formed.
Chip formation process.
The process of build-up.
All lathes, regardless of types and sizes, have the same type of components and parts.
A cartoon showing the main components of a lathe.
The bed of the lathe.
The frame on which all the main parts of the machine are mounted is made of cast iron and consists of two longitudinal walls connected by transverse stiffeners.
The bed can have flat, prismatic or mixed guides.
The carriage and tailstock move along the guides.
The headstock serves to transmit the main movement - the rotation of the workpiece.
The main part of the headstock is the spindle rotating in rolling and sliding bearings.
The front end of the spindle has a conical hole for mounting the front center and a threaded surface for mounting and securing the chuck or faceplate.
The spindle has a through hole for the rod material.
Disassembly and assembly of the lathe, fixing the rod in the spindle.
Setting different spindle rotations.
A mobile gear unit for switching spindle revolutions.
Friction and cam couplings.
A cartoon explaining the gear ratio.
Metal processing on a lathe is carried out in two coordinated movements.
The main movement is the rotation of the part.
Translational movement of the cutter.
A cartoon explaining how both types of movement are obtained.
A cartoon explaining the mechanisms of the cutter feed and details.
The cartoon frames are accompanied by filming of the lathe operation.
The change in the feed value is carried out by switching the control handle.
For threading on a lathe, it is necessary that the cutter receives a longitudinal displacement equal to the thread pitch for each revolution of the spindle, i.e. the speed of the longitudinal movement of the cutter must be consistent with the spindle rotation speed.
Such precise interaction is achieved with the help of a lead screw connected to the gear box of the gear system.
A cartoon explaining the work of kinematic circuits.
Inch thread cutting.
Metric and modular thread cutting.
Continuation of the cartoon explaining the work of kinematic circuits.
The device of the main components of the machine.
The apron is used to convert the rotational movement of the drive shaft or the lead screw into the translational movement of the caliper with the cutter.
Cartoon explaining the movement of the caliper during longitudinal turning.
Alternating with the frames of the lathe operation.
The rotational movement turns into translational, the longitudinal feed is carried out.
A cartoon explaining the movement of the caliper with a transverse feed.
Caliper control using the handle.
A cartoon explaining how the handle controls the movement of the caliper.
The direction of movement of the handle when turned on coincides with the direction of movement of the caliper.
Implementation of the auxiliary movement of the caliper using a special device.
A cartoon explaining the operation of the overtaking clutch in the feed box.
Turning on the engine of the overtaking clutch drive.
A cartoon explaining the operation of the accelerated drive.
Fixing the cutting tool in the caliper.
The carriage with a support moves along the guides of the bed.
Upper guides for the transverse movement of the caliper.
The rotary part of the caliper is installed on the transverse sled.
Turning the caliper to handle a small cone part.
It consists of a plate moved along the guides of the frame, a housing with a hole into which a pinole is inserted, a flywheel mounted on a screw.
Pinole use cases.
Two types of tailstock fastening.
Workshop with various types of lathes.
The device of the main components of the machine.