Machining is actually a surface forming process
How to form the work surface
Any surface can be regarded as the trajectory of a busbar moving along another wire. The busbar and wires are collectively referred to as the generating lines that form the surface.
How to form the occurrence line
The generation line is obtained by the relative motion between the cutting edge of the tool and the workpiece.
Relationship between cutting edge shape and generation line
1. The cutting edge shape is a single point,
2. The shape of the cutting edge is a cutting line, which completely matches the shape of the generating line 2 to be formed. When cutting, the cutting edge makes line contact with the surface to be cut.
3. The shape of the cutting edge is a cutting line, but it does not match the shape of the line that needs to be formed. During cutting, the cutting edge of the tool is tangent to the surface to be formed, which can be regarded as point contact. The cutting edge is relative to the workpiece. Rolling, that is, generating motion, the required forming line is the envelope of the cutting line of the tool, and the tool and the workpiece need to have conjugate generating motion
Methods of forming occurrence lines and required movements
1. Forming method
2. Development method
3. Trajectory method
4. Tangential method
Tool coordinate system
stationary coordinate system
Base plane, cutting plane, main section
Main section:
rake angle, front face and base surface
Relief angle, rear face and cutting plane
Wedge, front and back
Base:
Main deflection, the projection of the main cutting edge and the cutting direction on the bottom plane
Secondary offset, the projection of the secondary blade and the opposite direction of the tool feed on the bottom plane
Tool tip angle, the angle between the projection of the main and negative cutting edges on the bottom plane
Cutting plane:
Edge inclination angle, main cutting edge and base surface
The rake surface is determined by the tip, rake angle and blade
The flank surface is defined by the tip, relief angle, and cutting edge.
Cutting edge, defined by leading angle and edge inclination angle
Working coordinate system:
Working base surface, perpendicular to the resultant cutting speed
The working cutting plane is tangent to the cutting edge and perpendicular to the working base surface
Main working section, perpendicular to the first two faces
The working plane is a working plane that passes through the selected point on the cutting edge and contains both the main movement speed and the feed movement speed direction.
The influence of feed motion on the working coordinate system
The influence of the installation height of the tool tip on the working angle
Cutting layer parameters
Cutting method
Free cutting, single edge
Non-free cutting, curves or multiple edges
