Inspection Fixture Basic Principles and Components
Inspection fixtures are auxiliary devices on machine tools, serving as process equipment for mounting workpieces. For the workpiece to be formed, there must be relative movement between the workpiece and the cutting tool. Therefore, the position of the workpiece relative to the cutting tool must be determined, and this relative position must remain constant during the cutting process.
Checking the Fixture Positioning Principle
Six-Point Positioning Principle: A workpiece with six degrees of freedom operates in a Cartesian coordinate system. A fixture uses six rationally distributed support points to restrict each of these six degrees of freedom, completely defining the workpiece's position within the fixture. This is called the "six-point positioning principle."
Application of the Six-Point Positioning Principle-Complete Workpiece Positioning: When all six degrees of freedom are restricted by the fixture's positioning components, placing the workpiece in a completely defined position within the fixture, this is called complete positioning.
Application of the Six-Point Positioning Principle-Incomplete Workpiece Positioning: Positioning where some degrees of freedom are not restricted by the fixture's positioning components, and this does not affect machining requirements, is called incomplete positioning.
Positioning Structure
Positioning by round hole
Positioning by outer cylinder
Positioning by one pin on one side
Positioning by one pin on both sides
